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Crook JL, Pientka W, Zhang AY, Golden A, Koehler D, Sammer D. Risk factors for surgical site infection after surgical treatment of closed distal radial fractures. J Hand Surg Eur Vol 2024; 49:310-315. [PMID: 37666217 DOI: 10.1177/17531934231194672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
We assessed operatively treated closed distal radial fractures to identify independent risk factors for surgical site infection after treatment. A retrospective review was carried out of 531 operatively treated closed distal radial fractures over a 5-year period. Multiple logistic regression was performed with infection as the dependent variable, using a stepwise regression procedure to select variables to construct the final model. In total, 19 (3.6%) fractures were complicated by postoperative surgical site infection. Uncontrolled diabetes with HbA1c >7, the presence of external fixation or external Kirschner wires, and tobacco use were significant independent predictors of infection. Age and time in the operating room were also statistically significant predictors but deemed to be not clinically meaningful.Level of evidence: IV.
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Affiliation(s)
- Jennifer L Crook
- Department of Plastic Surgery, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - William Pientka
- Department of Orthopaedic Surgery, John Peter Smith Hospital, Fort Worth, TX, USA
| | - Andrew Y Zhang
- Department of Plastic Surgery, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Ann Golden
- Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Daniel Koehler
- Department of Orthopaedic Surgery, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
| | - Douglas Sammer
- Department of Plastic Surgery, University of Texas Southwestern Medical Center at Dallas, Dallas, TX, USA
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2
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Farewell JT, Perez K, Henderson S, Crook J, Hunter M, Zhang AY. Psychological impact of the COVID-19 pandemic on breast cancer patients. J Plast Reconstr Aesthet Surg 2023; 84:313-322. [PMID: 37390540 PMCID: PMC10257321 DOI: 10.1016/j.bjps.2023.06.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 06/06/2023] [Indexed: 07/02/2023]
Abstract
PURPOSE The COVID-19 pandemic uniquely impacted patients with breast cancer as mastectomies were allowed to proceed, yet breast reconstruction surgeries were halted. The purpose of this study was to examine the effect of the COVID-19 pandemic on the rates of breast reconstruction and patients' well-being. METHODS A chart review included all patients who underwent mastectomy from December 2019 to September 2021. Patients were contacted by a member of the research team and asked to participate in a COVID-19-specific survey and to complete the Hospital Anxiety and Depression Scale (HADS). Patients were then grouped into "surge" or "nonsurge" groups based on the date of mastectomy. RESULTS Two hundred and fifty-nine patients were included in this study. During the study period, 42% (n = 111) of the patients underwent breast reconstruction. The "surge" group included 106 patients whereas the "nonsurge" group included 153 patients. Fewer patients began breast reconstruction during the surge period compared with the nonsurge period (34.0% vs. 49.0%, p = 0.017). Eighty-six patients participated in the COVID-19 survey. Forty-one percent (n = 35) of the patients felt that their care was disrupted because of COVID-19. Eighty-three patients completed the HADS survey. Overall, 16.8% and 15.7% of the respondents fell into the moderate to severe ranges for both anxiety and depression scales, respectively. CONCLUSIONS Patients with breast cancer have faced increased difficulties with access to breast reconstruction throughout the COVID-19 pandemic. Our institution demonstrated decreased rates of breast reconstruction and an increase in anxiety and depression. The positive benefits of breast reconstruction cannot be overlooked when determining resource allocation in the future.
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Affiliation(s)
- Jordyn T Farewell
- University of Texas Southwestern, Department of Plastic Surgery, 1801 Inwood Road, Dallas, TX, USA
| | - Kevin Perez
- University of Texas Southwestern, Department of Plastic Surgery, 1801 Inwood Road, Dallas, TX, USA
| | - Silas Henderson
- Baylor College of Medicine, Department of Surgery, Houston, TX, USA
| | - Jennifer Crook
- University of Texas Southwestern, Department of Plastic Surgery, 1801 Inwood Road, Dallas, TX, USA
| | - Madysen Hunter
- University of Texas Southwestern, Department of Plastic Surgery, 1801 Inwood Road, Dallas, TX, USA
| | - Andrew Y Zhang
- University of Texas Southwestern, Department of Plastic Surgery, 1801 Inwood Road, Dallas, TX, USA.
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3
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Meade A, Wisecarver I, Cho MJ, Davis JJ, Duque S, Farewell JT, Zhang AY. The Role of Reconstruction on Desmoid Tumor Recurrence: A Systematic Review and Technical Considerations. Ann Plast Surg 2023; 90:S195-S202. [PMID: 36729103 DOI: 10.1097/sap.0000000000003381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Desmoid tumors occur throughout the body, presenting as aggressive, locally invasive lesions that can impede quality of life. Many controversies remain regarding the optimal surgical treatment of desmoid. This article presents a systematic review and meta-analysis on surgical management, focusing on risk of recurrence and the utility of reconstruction within this unique patient population. METHODS A systematic review was conducted to search for articles. The clinical course of patients diagnosed with desmoid tumors and treated by our institution's multidisciplinary team was retrospectively reviewed over a 13-year period. Meta-analysis study findings were compared with our cohort. RESULTS From the systematic review, 10 studies with level of evidence III were found, which resulted in 981 patients. Twenty patients from our institution met the inclusion criteria for our study. In both our study cohort and the pooled results, recurrence was significantly higher in patients with positive microscopic margin after resection. In our study cohort, patients with recurrence had higher rates of positive margins compared with those without recurrence (83.3% vs 7.1%, P = 0.004), whereas the pooled study showed a difference of margin positivity of 50% vs 40% ( P = 0.01). No patients who underwent reconstruction in our study cohort had a recurrence during the study period. CONCLUSION In both our cohort and pooled results, recurrence was significantly higher in patients with positive margins after initial resection. Reconstruction was not found to be a risk factor for recurrence. Reconstruction following desmoid tumor resection should be considered a viable option if a large and aggressive resection is required to obtain negative margins.
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Affiliation(s)
- Anna Meade
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX
| | - Ian Wisecarver
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX
| | - Min-Jeong Cho
- Department of Plastic and Reconstructive Surgery, The Ohio State University College of Medicine, Columbus, OH
| | - Justin J Davis
- Institute for Plastic Surgery, Southern Illinois University, Springfield, IL
| | - Sofia Duque
- Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA
| | - Jordyn T Farewell
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX
| | - Andrew Y Zhang
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX
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4
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May JM, Pathak A, Pientka WF, Meade AE, Duque S, Farewell JT, Zhang AY. Static and Dynamic Stabilization of the Shoulder After Total Scapulectomy in an Electric Burn Patient. Ann Plast Surg 2023; 90:S216-S220. [PMID: 36752401 DOI: 10.1097/sap.0000000000003392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
ABSTRACT An otherwise healthy 49-year-old man experienced a high-voltage electrical injury to the left shoulder resulting in total scapulectomy, partial calviculectomy, and a substantial soft tissue defect. The majority of the muscles around his shoulder were debrided because of necrosis, with only the pectoralis and latissimus dorsi muscles remaining attached to the humerus. Surprisingly, the patient's brachial plexus remained intact, and his left elbow, wrist, and hand function were preserved. A novel combination of 3 static and dynamic suspension techniques were used to stabilize his shoulder and prevent traction injury to the brachial plexus. Postoperative follow-up at 1 year demonstrated excellent stability of his reconstructed shoulder, which allowed him to ambulate independently and return to employment.
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Affiliation(s)
- Jessica M May
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX
| | | | | | - Anna E Meade
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX
| | - Sofia Duque
- Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA
| | - Jordyn T Farewell
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX
| | - Andrew Y Zhang
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX
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5
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Seaward JR, Carter LR, Nagarkar P, Zhang AY. Rating the Rater: A Technique for Minimizing Leniency Bias in Residency Applications. Plast Reconstr Surg Glob Open 2023; 11:e4892. [PMID: 37101610 PMCID: PMC10125539 DOI: 10.1097/gox.0000000000004892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 02/03/2023] [Indexed: 04/28/2023]
Abstract
Each program in the highly competitive match for a surgical residency needs a way to review applicants effectively. Often this task is undertaken by individual faculty members, reviewing an applicant's file and assigning a score. Despite being asked to rate on a standardized scale, our program found that ratings of the same applicants varied dramatically, with certain faculty consistently scoring higher or lower than others. This is termed leniency bias, or the Hawk-Dove effect, and can affect who is invited to interview depending on which faculty are assigned to review an applicant's file. Methods A technique to minimize leniency bias was developed and applied to this year's 222 applicants for our plastic surgery residency. The effect of the technique was evaluated by comparing variance between ratings of the same applicants by different faculty before and after our technique. Results The median variance of ratings of the same applicants reduced from 0.68 before correction to 0.18 after correction, demonstrating better agreement between raters of the applicants' scores after our technique had been applied. This year, applying our technique affected whether or not 16 applicants (36% of interviewees) were invited for interview, including one applicant who matched to our program but who otherwise would not have been offered an interview. Conclusions We present a simple but effective technique to minimize the leniency bias between raters of residency applicants. Our experience with this technique is presented together with instructions and Excel formulae for other programs to use.
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Affiliation(s)
- James R. Seaward
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, Tex
| | - Lillian R. Carter
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, Tex
| | - Purushottam Nagarkar
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, Tex
| | - Andrew Y. Zhang
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, Tex
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6
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Abstract
BACKGROUND Pollicization of the index finger is a rarely performed reconstructive option for patients with total thumb amputations with nonsalvageable carpometacarpal (CMC) joint and thenar muscles. Successful pollicization can provide basic grasp and pinch to help patients carry out activities of daily living. We present a retrospective review of 4 patients who underwent index finger pollicization for traumatic total thumb amputations. METHODS A retrospective review of 4 cases of pollicization using an injured index finger for traumatic thumb amputation was performed. Patients available for follow-up were contacted for functional assessment. Outcomes including range of motion (ROM), grip strength, key pinch, 2-point discrimination, and Disabilities of the Arm, Shoulder, and Hand score were obtained. Functional thenar muscle and the CMC joint were absent in all cases. Injury mechanism was firework in 2 patients and crush in 2 patients. RESULTS The time from injury to pollicization ranged from 8 days to 17 months. Follow-up time ranged from 10 weeks to 3 years. Three patients regularly used the pollicized thumb in activities of daily living such as writing. Tip pinch and lateral pinch along with grip strength were weak in all cases; the best recorded pinch strength was 24% and grip strength was 25% compared with the contralateral hand. The ROM of the pollicized thumb was limited. CONCLUSIONS Index finger pollicization following total thumb amputation can be a viable last-resort option for patients. The pollicized digit acts as a sensate post and avoids further morbidity from the traumatized extremity.
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Affiliation(s)
- Ryan M Dickey
- University of Texas Southwestern Medical Center, Dallas, USA
| | - Anna E Meade
- University of Texas Southwestern Medical Center, Dallas, USA
| | | | - Andrew Y Zhang
- University of Texas Southwestern Medical Center, Dallas, USA
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7
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Urquia LN, Henderson SP, Farewell JT, Duque S, Garibay M, Nevin J, Zhang AY. Tissue Expander-Based Breast Reconstruction at a Major Safety-Net Hospital: Managing the Outsized Risk of Infection. Aesthet Surg J Open Forum 2022; 4:ojac036. [PMID: 35673613 PMCID: PMC9167491 DOI: 10.1093/asjof/ojac036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background Immediate tissue expander (TE) breast reconstruction is reported to have the highest rate of postoperative infection among reconstructive modalities. The risk of infection is higher among patients treated at safety-net hospitals. Objectives The goal of this study was to identify significant contributing factors to the elevated infection risk at our major safety-net institution. Methods A retrospective chart review was conducted on all TE-based reconstruction patients with a diagnosis of postoperative infection between 2015 and 2019. Preoperative, perioperative, and postoperative risk factors for infection were determined and compared across patient and procedure demographics. Results Two hundred forty-three patients, for a total of 412 breast reconstructions, were included in our study. Significant preoperative selection factors were identified to contribute to the elevated risk of infection, including the following: older age, higher BMI, and diabetes. Significant intraoperative and postoperative contributing factors included greater mastectomy weight, larger TE's and intraoperative fill volume, and longer drain duration. Doxycycline treatment for infected patients resulted in a significantly higher rate of resolution. Conclusions Safety-net hospital population patients undergoing TE breast reconstruction are at higher risk for postoperative infection. Personal and procedural risk factors are identified. Balancing the benefits of immediate breast reconstruction with TEs with the elevated risk of postoperative infection remains challenging. Implementation of more stringent eligibility criteria may help mitigate the risk of infection. Level of Evidence 4
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Affiliation(s)
- Lindsey N Urquia
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Silas P Henderson
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jordyn T Farewell
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sofia Duque
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Maycie Garibay
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Julia Nevin
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Andrew Y Zhang
- Corresponding Author:Dr Andrew Y. Zhang, Department of Plastic Surgery, University of Texas Southwestern Medical Center, 1801 Inwood Road, 4th Floor, Dallas, TX 75390, USA. E-mail:
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8
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Meade A, Cummins S, Farewell JT, Duque S, Mulqueen S, Chuah A, Zhang AY. 56. BREAKING BARRIERS TO BREAST RECONSTRUCTION AMONG SOCIOECONOMICALLY DISADVANTAGED BREAST CANCER PATIENTS: LESSONS LEARNED AT A LARGE SAFETY-NET HOSPITAL. Plast Reconstr Surg Glob Open 2022. [PMCID: PMC8984366 DOI: 10.1097/01.gox.0000828212.40138.cd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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9
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Abstract
Background The type of content that influences plastic and reconstructive surgery (PRS) residency program selection and attracts applicants is everchanging and not clearly understood. Further, the COVID-19 pandemic had a major impact on residency selection that is undetermined. Objectives The purpose of this study was to determine to what degree and the type of PRS SM content that drives prospective applicants’ interest of a residency program, especially in the context of COVID-19. Methods Prospective PRS residency applicants were surveyed anonymously. Results An average of 60% of respondents reported that PRS social media (SM) content influenced their perception of a program. Fifty-eight percent reported that resident lifestyle content made them gain interest in a program. Separately, 32% reported that resident lifestyle content influenced them to rank a program higher. Seventy-two percent of respondents claimed SM content did not make them lose interest in a program. Rarely posting, outdated content, and lack of engagement were cited as factors for loss of interest in a program. A majority of respondents (53%) reported wanting to see more resident life and culture content on SM. Of the existing PRS SM content, respondents were most interested in resident lifestyle, followed by clinical and program-specific content. Conclusions The COVID-19 pandemic amplified the importance of SM PRS residency selection. Resident lifestyle content was consistently indicated as more likely to make respondents gain interest in a program, rank a program higher, and as the most desired content. PRS programs will benefit from highlighting resident camaraderie, quality of life, hobbies, and lifestyle to attract applicants.
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Affiliation(s)
- Sofia Duque
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Vincent Riccelli
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Sydney Mulqueen
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Andrew Y Zhang
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
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10
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Abstract
INTRODUCTION Firearm morbidity and mortality have been increasing in recent years, and with this, the demand for medical personnel firearm injury treatment knowledge. Extremities contribute to a majority of firearm injuries, with these injuries being particularly complex because of neurovascular proximity within a confined space. Knowledge of firearm mechanism of injury and treatment management options is important for any trauma hand surgeon. Many factors play vital roles in the treatment of complex upper extremity (UE) gunshot wounds (GSWs). The aim of our review and case illustrations is to provide hand surgeons with an up-to-date guide for initial emergent management, soft tissue, bony, and nerve repair and reconstruction. PATIENT AND METHODS A literature review was conducted in the current management of UE GSW injuries, and 2 specific patient case examples were included. High-energy versus low-energy GSWs were documented and compared, as well as containment injures. Management including soft tissue, bony, and nerve injuries was explored along with patient outcome. Based on these findings, guidelines for GSW management were purposed. CONCLUSION Gunshot wounds of the UE encompass a group of highly heterogeneous injuries. High-energy wounds are more extensive, and concomitant injuries to bone, vessel, nerve, muscle, and soft tissue are common. Early treatment with adequate debridement, skeletal fixation, and soft tissue coverage is indicated for complex injuries, and antibiotic treatment in the pre-, peri-, and postoperative period is indicated for operative injuries. Soft tissue coverage options include the entire reconstructive ladder, with pattern of injury and considerations of wound characteristics dictating reconstructive choice. There are arguments to using either external or internal bony fixation techniques for bone fracture management, with choice tailored to the patient. For management of nerve injuries, we advocate earlier nerve repair and a shorter duration of observation before secondary reconstruction in selective cases. If transected nerve endings cannot be brought together, nerve autografts of shorter length are recommended to bridge nerve ending gaps. A significant number of patients with GSW fail to make necessary follow-up appointments, which adds to challenges in treatment.
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Affiliation(s)
- Anna Meade
- From the Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX
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11
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Abstract
BACKGROUND Complications associated with autologous breast reconstruction are well reported in the literature. Regardless of the type of free flap harvested, the anastomosis is most commonly performed to the recipient internal mammary vessels. Although pneumothorax is a known possible complication of breast surgery, incidence of pneumothorax in breast reconstruction involving the use of the internal mammary vessels is rarely discussed. The aim of our study was to determine the incidence of pneumothorax in deep inferior epigastric perforator (DIEP) flap breast reconstruction. METHODS A single-institution review was performed examining the incidence of pneumothorax in cases of DIEP flap breast reconstruction with anastomosis to the internal mammary vessels over a 4-year period. Intraoperative irrigation was used to visually assess for evidence of pneumothorax during recipient vessel dissection and anastomosis. Anteroposterior chest radiographs were obtained on the first postoperative day to assess for pneumothorax. Additional variables analyzed included type of retractor used during recipient vessel dissection and history of radiation. RESULTS A total of 180 patients underwent autologous DIEP breast reconstruction at our institution. The overall incidence of pneumothorax was 1.4 per 100 recipient vessel dissections and 2.2 per 100 patients undergoing breast reconstruction. There was a total of 4 cases of pneumothorax. Three were attributed to unknown causes, and 1 was due to direct injury to the parietal pleura via electrocautery. CONCLUSION The use of the internal mammary artery and vein as recipient vessels continues to be the most common and reliable recipient for autologous breast reconstruction. Based on our data, pneumothorax does not seem to be a common complication of this procedure. If concern for iatrogenic injury to the pleura arises intraoperatively, we suggest the use of a saline bubble test to investigate the possible injury. Routine postoperative radiographs are not indicated unless the patient develops symptoms suggestive of pneumothorax.
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Affiliation(s)
- Joseph A Kelling
- From the Department of Plastic Surgery, University of Texas at Southwestern Medical Center, Dallas, TX
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12
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Zhang AY. Commentary on: Insta-Grated Plastic Surgery Residencies: 2020 Update. Aesthet Surg J 2021; 41:383-384. [PMID: 33000127 DOI: 10.1093/asj/sjaa216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Andrew Y Zhang
- Department of Plastic Surgery, UT Southwestern Medical Center, Dallas, TX
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13
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Abstract
Background: Skeletal muscle lacerations are a relatively common injury. Compared with nonrepaired lacerations, surgically repaired muscle lacerations regenerate faster, develop less scar tissue, have a higher return to baseline strength, and have lower incidence of hematomas. Despite the benefits of repair, the optimal repair technique is still unknown. The purpose of this study was to examine the biomechanical properties of common muscle repair techniques to determine the optimal repair. Methods: Forty-two fusiform porcine muscle specimens were dissected and used for this study. Three suture techniques were used for comparative analysis: Figure-eight, Mason Allen, and Perimeter. Each muscle was transected and then repaired using one of the 3 techniques. Fourteen muscle-tendon specimens were prepared for each group and tested for tensile failure using a material testing system. Biomechanical properties, including peak failure point and stiffness, were compared for differences between the suture groups by 1-way analysis of variance. The average time per repair technique was also recorded. Results: The Perimeter technique showed a statistically significant higher peak failure point than the Mason Allen technique (P = .03). Both the Figure-eight (P = .047) and Perimeter techniques (P < .001) were significantly stiffer than the Mason Allen technique. The repair time was comparable across all 3 techniques. Conclusions: The Figure-eight and Perimeter repairs were found to be similar in peak failure point and stiffness, whereas the Mason Allen technique showed significantly lower stiffness and peak failure point. The Figure-eight was the quickest repair to perform. The Figure-eight technique may be strongly considered for muscle laceration repairs due to its simplicity and efficiency.
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Affiliation(s)
| | | | - Randal Morris
- The University of Texas Medical Branch
at Galveston, USA
| | | | - Surjit Rai
- The University of Texas Medical Branch
at Galveston, USA
| | | | - Dat Tran
- The University of Texas Medical Branch
at Galveston, USA
| | - Ludwik Branski
- The University of Texas Medical Branch
at Galveston, USA
| | - Andrew Y. Zhang
- University of Texas Southwestern,
Dallas, USA,Andrew Y. Zhang, Department of Plastic
Surgery, University of Texas Southwestern, 1801 Inwood Road, 4th Floor, Dallas,
TX 75390-1932, USA.
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14
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Kirby B, Kenkel JM, Zhang AY, Amirlak B, Suszynski TM. Three-dimensional (3D) synthetic printing for the manufacture of non-biodegradable models, tools and implants used in surgery: a review of current methods. J Med Eng Technol 2020; 45:14-21. [PMID: 33215944 DOI: 10.1080/03091902.2020.1838643] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The advent of three-dimensional (3D) printing in the 1980s ushered in a new era of manufacturing. Original 3D printers were large, expensive and difficult to operate, but recent advances in 3D printer technologies have drastically increased the accessibility of these machines such that individual surgical departments can now afford their own 3D printers. As adoption of 3D printing technology has increased within the medical industry so too has the number of 3D printable materials. Selection of the appropriate printer and material for a given application can be a daunting task for any clinician. This review seeks to describe the benefits and drawbacks of different 3D printing technologies and the materials used therein. Commercially available printers using fused deposition modelling or fused filament fabrication technology and relatively inexpensive thermoplastic materials have enabled rapid manufacture of anatomic models and intraoperative tools as well as implant prototyping. Titanium alloys remain the gold-standard material for various implants used in the fixation of craniofacial or extremity fractures, but polymers and ceramics are showing increasing promise for these types of applications. An understanding of these materials and their compatibility with various 3D printers is essential for application of this technology in a healthcare setting.
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Affiliation(s)
- Benjamin Kirby
- Department of Surgery, University of Missouri Health Care, Columbia, MO, USA
| | - Jeffrey M Kenkel
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Andrew Y Zhang
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Bardia Amirlak
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Thomas M Suszynski
- Department of Plastic Surgery, University of Texas Southwestern Medical Center, Dallas, TX, USA
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15
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Cho MJ, Halani SH, Davis J, Zhang AY. Achieving balance between resident autonomy and patient safety: Analysis of resident-led microvascular reconstruction outcomes at a microsurgical training center with an established microsurgical training pathway. J Plast Reconstr Aesthet Surg 2020; 73:118-125. [DOI: 10.1016/j.bjps.2019.07.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/09/2019] [Accepted: 07/27/2019] [Indexed: 10/26/2022]
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16
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Zhang AY, Judson I, Benson C, Wunder JS, Ray-Coquard I, Grimer RJ, Quek R, Wong E, Miah AB, Ferguson PC, Dufresne A, Teh JYH, Stockler M, Tattersall MHN. Author Correction: Chemotherapy with radiotherapy influences time-to-development of radiation-induced sarcomas: a multicenter study. Br J Cancer 2018; 118:1682. [PMID: 29808016 PMCID: PMC6008468 DOI: 10.1038/s41416-018-0079-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Since the publication of this paper, the authors noticed an error in Fig. 1. The X-axis on all the figure panels should read 'Time (years)', not 'Time (months)'. The corrected Fig. 1 is shown below.
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Affiliation(s)
- A Y Zhang
- The University of Sydney, Sydney, 2006, Australia. .,Chris O'Brien Lifehouse, Sydney, 2050, Australia.
| | - I Judson
- Royal Marsden NHS Foundation Trust, London, SW3 6JJ, UK
| | - C Benson
- Royal Marsden NHS Foundation Trust, London, SW3 6JJ, UK
| | - J S Wunder
- Musculoskeletal Oncology Unit, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.,Department of Surgery, University of Toronto, Toronto, ON, M5S, Canada
| | - I Ray-Coquard
- Centre Léon Bérard, University Claude Bernard, Lyon, 69100, France
| | - R J Grimer
- The Royal Orthopaedic Hospital NHS Trust, Birmingham, B31 2AP, UK
| | - R Quek
- National Cancer Centre, Singapore, 169610, Singapore
| | - E Wong
- Royal Marsden NHS Foundation Trust, London, SW3 6JJ, UK
| | - A B Miah
- Royal Marsden NHS Foundation Trust, London, SW3 6JJ, UK
| | - P C Ferguson
- Musculoskeletal Oncology Unit, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada.,Department of Surgery, University of Toronto, Toronto, ON, M5S, Canada
| | - A Dufresne
- Centre Léon Bérard, University Claude Bernard, Lyon, 69100, France
| | - J Y H Teh
- National Cancer Centre, Singapore, 169610, Singapore
| | - M Stockler
- Chris O'Brien Lifehouse, Sydney, 2050, Australia.,NHMRC Clinical Trials Centre, University of Sydney, Sydney, 2006, Australia
| | - M H N Tattersall
- The University of Sydney, Sydney, 2006, Australia.,Chris O'Brien Lifehouse, Sydney, 2050, Australia
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17
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Zhang AY, Grogan JS, Mahon KL, Rasiah K, Sved P, Eisinger DR, Boulas J, Vasilaris A, Henshall SM, Stricker PD, Kench JG, Horvath LG. A prospective multicentre phase III validation study of AZGP1 as a biomarker in localized prostate cancer. Ann Oncol 2018; 28:1903-1909. [PMID: 28486686 DOI: 10.1093/annonc/mdx247] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Background Prostate cancers (PCs) with similar characteristics at the time of diagnosis can have very different disease outcomes. Conventional biomarkers of PC still lack precision in identifying individuals at high risk of PC recurrence. While many candidate biomarkers are proposed in the literature, few are in clinical practice as they lack rigorous validation. This study prospectively enrolled an independent phase III cohort to evaluate the clinical utility of zinc-alpha 2-glycoprotein (AZGP1) as a prognostic biomarker in localized PC. Patients and methods In our multicentre, prospective phase III study, AZGP1 status in 347 radical prostatectomy specimens was assayed by immunohistochemistry in a NATA-accredited laboratory. The AZGP1 score was assessed in a multivariable model incorporating established prognostic factors. We also report extended outcomes from our previous phase II study. The primary endpoint was biochemical relapse-free survival (BRFS). Secondary endpoints were metastasis-free survival (MFS) and PC-specific survival (PCSS). Results In the phase II cohort, with a median follow-up of 15.8 years, low/absent AZGP1 expression was an independent predictor of poor BRFS (HR, 1.4; 95% CI, 1.1-1.9; P = 0.03), MFS (HR, 2.8; 95% CI, 1.2-6.6; P = 0.02) and PCSS (HR, 3.8; 95% CI, 1.5-9.5; P = 0.005). These results were validated in our prospective phase III cohort. Low/absent AZGP1 expression independently predicted for BRFS (HR, 1.9; 95% CI, 1.1-3.3; P = 0.02), with shorter MFS (HR, 2.0; 95% CI, 1.1-3.4; P = 0.02). AZGP1 improved the discriminatory value when incorporated into existing prognostic risk models. Conclusion Our study provides prospective phase III validation that absent/low AZGP1 expression provides independent prognostic value in PC. This study provides robust evidence for the incorporation of this biomarker into clinical practice.
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Affiliation(s)
- A Y Zhang
- Department of Medical Oncology, Chris O'Brien Lifehouse, Camperdown.,Cancer Division, Garvan Institute of Medical Research/The Kinghorn Cancer Centre, Darlinghurst.,Sydney Medical School, University of Sydney, Camperdown
| | - J S Grogan
- Cancer Division, Garvan Institute of Medical Research/The Kinghorn Cancer Centre, Darlinghurst
| | - K L Mahon
- Department of Medical Oncology, Chris O'Brien Lifehouse, Camperdown.,Cancer Division, Garvan Institute of Medical Research/The Kinghorn Cancer Centre, Darlinghurst
| | - K Rasiah
- Cancer Division, Garvan Institute of Medical Research/The Kinghorn Cancer Centre, Darlinghurst.,Sydney Medical School, University of Sydney, Camperdown.,Department of Urology, Royal North Shore Hospital, Crows Nest
| | - P Sved
- Sydney Medical School, University of Sydney, Camperdown.,Department of Urology, Royal Prince Alfred Hospital, Camperdown, Australia
| | - D R Eisinger
- Department of Urology, Royal Prince Alfred Hospital, Camperdown, Australia
| | - J Boulas
- Department of Urology, Royal Prince Alfred Hospital, Camperdown, Australia
| | - A Vasilaris
- Department of Urology, Royal Prince Alfred Hospital, Camperdown, Australia
| | - S M Henshall
- Three Stories Consulting - Global Health Advocacy, USA
| | - P D Stricker
- Cancer Division, Garvan Institute of Medical Research/The Kinghorn Cancer Centre, Darlinghurst.,Sydney Medical School, University of Sydney, Camperdown.,Department of Urology, St Vincent's Clinic, Darlinghurst.,Discipline of Medicine, University of New South Wales
| | - J G Kench
- Cancer Division, Garvan Institute of Medical Research/The Kinghorn Cancer Centre, Darlinghurst.,Sydney Medical School, University of Sydney, Camperdown.,Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Camperdown, Australia
| | - L G Horvath
- Department of Medical Oncology, Chris O'Brien Lifehouse, Camperdown.,Cancer Division, Garvan Institute of Medical Research/The Kinghorn Cancer Centre, Darlinghurst.,Sydney Medical School, University of Sydney, Camperdown.,Discipline of Medicine, University of New South Wales.,Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Camperdown, Australia
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18
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Abstract
As an anti-inflammatory cytokine, interleukin-37 (IL-37) provides certain protective effects against inflammatory and autoimmune diseases. Recent reports indicate that IL-37 is expressed in foam cells of atherosclerotic plaques in both the coronary and carotid arteries of humans, suggesting the possible involvement of IL-37 in the pathogenesis and progression of atherosclerosis. Current evidence supports the protective role that IL-37 plays against atherosclerosis via the regulation of different subtypes of macrophage. Atherosclerosis was induced in apolipoprotein E -/- mice through diet, and the mice were then given IL-37 to observe patterns in the aorta plaque. Furthermore, human peripheral blood-derived monocytes were cultured for seven days to induce the differentiation of macrophages. Specifically, we observed the effect of IL-37 on oxygenated low density lipoprotein (ox-LDL)-induced macrophage polarity, in addition to conducting an expressional assay of the M1 cell markers tumor necrosis factor (TNF)-α and CD86 and the M2 marker CD206. IL-37 effectively decreased the area ratio between the aorta plaque and vascular cavity. We also observed that M1 macrophages can be induced from peripheral monocytes by ox-LDL, with significant elevation of marker molecules TNF-α and CD86. The co-stimulation of IL-37 and ox-LDL, however, inhibited the induction of M1 cells and facilitated the transformation of macrophages into M2 cells, as supported by the elevation of cell-specific marker CD206. These results indicate that IL-37 can prevent atherosclerosis by modulating macrophage polarity.
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Affiliation(s)
- J Huang
- Department of Cardiology, Weifang People's Hospital, Weifang, Shandong, China
| | - F L Hou
- Department of Health, Weifang People's Hospital, Weifang, Shandong, China
| | - A Y Zhang
- Department of Cardiology, Weifang People's Hospital, Weifang, Shandong, China
| | - Z L Li
- Department of Health, Weifang People's Hospital, Weifang, Shandong, China
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19
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Abstract
Pain is a unique somatosensory perception that can dramatically affect our ability to function. It is also a necessary perception, without which we would do irreparable damage to ourselves. In this article, the authors assess the impact of pain on function of the hand. Pain can be categorized into acute pain, chronic pain, and neuropathic pain. Hand function and objective measurements of hand function are analyzed as well as the impact of different types of pain on each of these areas.
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Affiliation(s)
- Nicholas Howland
- Division of Plastic Surgery, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77550, USA
| | - Mariela Lopez
- Division of Plastic Surgery, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77550, USA
| | - Andrew Y Zhang
- Division of Plastic Surgery, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77550, USA.
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20
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Abstract
BACKGROUND Music is commonly played in operating theaters. Some surgeons believe music reduces stress and operative time, while others think music is a distraction and should be avoided. There is limited published evidence evaluating the effects of music on surgical performance. OBJECTIVE The goal of this study is to evaluate the effect of music on simple wound closure. METHODS Plastic surgery residents were asked to perform layered closures on pigs' feet with and without their preferred music playing. Simple randomization was used to assign residents to the music playing first or music playing second group. The time to complete the repair was measured and repairs were graded by blinded faculty. Results were analyzed to determine significant differences in time to complete the task and quality of repair. Participants were retested in a second session with music played in the opposite order to evaluate consistency. RESULTS Listening to preferred music decreased repair time by 8% for all plastic surgery residents (p = 0.009). Subgroup analysis demonstrated even more significant improvement in speed for senior residents (PGY 4-6), resulting in a 10% decrease in repair time (p = 0.006). The quality of repair was also better in the music group, at 3.3 versus 3.1 (p = 0.047). Retesting revealed results remained significant whether music was played first or second. CONCLUSIONS Playing preferred music made plastic surgery residents faster in completing wound closure with a 10% improvement in senior residents. Music also improved quality of repair as judged by blinded faculty. Our study showed that music improves efficiency of wound closure, which may translate to healthcare cost savings.
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Affiliation(s)
- Shelby R Lies
- From the Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Texas Medical Branch, Galveston, TX
| | - Andrew Y Zhang
- From the Division of Plastic and Reconstructive Surgery, Department of Surgery, University of Texas Medical Branch, Galveston, TX
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21
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Abstract
We describe an unusual case of trans-scaphoid perilunate injury where the proximal half of the scaphoid avulsed from all attaching ligaments and extruded into the forearm. Treatment involved anatomic reduction and internal fixation of the fracture, scapholunate (SL) ligament repair, temporary K-wire fixation, and prolonged immobilization. At 19-month follow-up, the fracture healed, SL ligament remained intact, and the patient recovered much of his hand function.
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Affiliation(s)
- Lisa Moody
- Division of Plastic and Reconstructive Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0724 USA
| | - Andrew Y. Zhang
- Division of Plastic and Reconstructive Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555-0724 USA
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22
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Zhang AY, Van Nortwick S, Hagert E, Ladd AL. Thumb carpometacarpal ligaments inside and out: a comparative study of arthroscopic and gross anatomy from the robert a. Chase hand and upper limb center at stanford university. J Wrist Surg 2013; 2:55-62. [PMID: 24436790 PMCID: PMC3656572 DOI: 10.1055/s-0033-1333683] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Purpose We propose to identify and correlate arthroscopic internal ligaments with external ligaments, providing an accurate roadmap for arthroscopic ligament and joint anatomy. Ligamentous laxity is considered an important risk factor in developing the common basilar arthritis of the thumb. Controversy exists as to the precise ligamentous anatomy of the thumb carpometacarpal (CMC) joint (CMC-I); description of the internal arthroscopic anatomy is limited. Methods We performed CMC-I joint arthroscopy using the 1-Ulnar (1U) and thenar portals in five cadavers, seeking to identify the following seven ligaments arthroscopically: the superficial anterior oblique ligament (sAOL), deep anterior oblique ligament (dAOL), ulnar collateral ligament (UCL), dorsal trapeziometacarpal ligament (DTM-1), posterior oblique ligament (POL), dorsal central ligament (DCL), and dorsal radial ligament (DRL). After grading articular changes of the trapezium, we passed Kirschner wires (K-wires) (0.028) outside-in to mark the arthroscopic insertion of each ligament on the trapezium. Gross dissection was performed to confirm the wire placement; the anatomic identity and position of joint stabilizing ligaments, and the location of frequently used portals. Results The volar ligaments-the sAOL, dAOL, and UCL-were highly variable in their arthroscopic appearance and precise location. The sAOL is a thin veil of membranous tissue that variably drapes across the anterior joint capsule. The reported dAOL and UCL, in our study, correlated to a thickened portion of this veil around the volar beak and was not consistently identified with gross dissection. In contrast, the arthroscopic appearance and location of the dorsal ligaments-DTM-I, POL, DCL, and DRL-were consistent in all specimens. Conclusion Our study further defines and correlates the arthroscopic and external ligamentous anatomy of the CMC-I joint.
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Affiliation(s)
| | | | - Elisabet Hagert
- Stanford, University, Palo Alto, California
- Karolinska Institutet, Solna, Sweden
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23
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Saber S, Zhang AY, Ki SH, Lindsey DP, Smith RL, Riboh J, Pham H, Chang J. Flexor Tendon Tissue Engineering: Bioreactor Cyclic Strain Increases Construct Strength. Tissue Eng Part A 2010; 16:2085-90. [DOI: 10.1089/ten.tea.2010.0032] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Sepideh Saber
- Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Stanford, California
- Division of Plastic and Reconstructive Surgery, VA Palo Alto Health Care System, Palo Alto, California
| | - Andrew Y. Zhang
- Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Stanford, California
- Division of Plastic and Reconstructive Surgery, VA Palo Alto Health Care System, Palo Alto, California
| | - Sae H. Ki
- Division of Plastic and Reconstructive Surgery, VA Palo Alto Health Care System, Palo Alto, California
| | - Derek P. Lindsey
- Bone & Joint Center Rehabilitation R&D Center, VA Palo Alto Health Care System, Palo Alto, California
| | - Robert Lane Smith
- Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Stanford, California
- Division of Plastic and Reconstructive Surgery, VA Palo Alto Health Care System, Palo Alto, California
| | - Jonathan Riboh
- Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Stanford, California
- Division of Plastic and Reconstructive Surgery, VA Palo Alto Health Care System, Palo Alto, California
| | - Hung Pham
- Division of Plastic and Reconstructive Surgery, VA Palo Alto Health Care System, Palo Alto, California
| | - James Chang
- Division of Plastic and Reconstructive Surgery, Stanford University Medical Center, Stanford, California
- Division of Plastic and Reconstructive Surgery, VA Palo Alto Health Care System, Palo Alto, California
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Abstract
This is a case report of a 61-year-old cardiac transplant patient who developed a disseminated infection involving the upper extremity with a rare fungus known as Aspergillus ustus. The patient was successfully treated with aggressive serial debridements, antifungal medications, and reduction of immunosuppression. With these interventions, the patient avoided amputation despite the aggressive nature of this infection.
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Affiliation(s)
- Olushola Olorunnipa
- Division of Plastic Surgery, School of Medicine, Stanford University, Suite 400, 770 Welch Rd., Palo Alto, CA 94304 USA
| | - Andrew Y. Zhang
- Division of Plastic Surgery, School of Medicine, Stanford University, Suite 400, 770 Welch Rd., Palo Alto, CA 94304 USA
| | - Catherine M. Curtin
- Division of Plastic Surgery, School of Medicine, Stanford University, Suite 400, 770 Welch Rd., Palo Alto, CA 94304 USA ,Department of Surgery, Palo Alto VA, 3801 Miranda Ave., Palo Alto, CA 94304 USA
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25
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Zhang AY, Bates SJ, Morrow E, Pham H, Pham B, Chang J. Tissue-engineered intrasynovial tendons: optimization of acellularization and seeding. ACTA ACUST UNITED AC 2010; 46:489-98. [PMID: 19882484 DOI: 10.1682/jrrd.2008.07.0086] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The purpose of this research was to develop a tissue-engineered intrasynovial flexor tendon construct with the use of an acellularized flexor tendon scaffold repopulated with intrasynovial tendon cells. New Zealand white rabbit intrasynovial flexor tendons were acellularized by the following methods: high concentration NaCl + SDS, Trypsin/EDTA, Trypsin/EDTA + Triton X-100, Triton X-100, Triton X-100 + SDS, and freezing at -70 degrees C followed by Trypsin/EDTA + Triton X-100. Epitenon and endotenon cells were also isolated from rabbit intrasynovial tendons and expanded in culture. Acellularized tendon scaffolds were then reseeded with these cells. A subset of epitenon and endotenon cells was labeled with green and red fluorescent markers, respectively, to further characterize the preferred location of their attachment. Optimal acellularization was achieved by freezing at -70 degrees C followed by Trypsin/EDTA + Triton X-100. After reseeding, light microscopy of tendon constructs showed attachment of both epitenon and endotenon to the tendon scaffolds, with endotenon cells more likely to be found in the core of the scaffold. An intrasynovial tendon construct was developed with the use of acellularized intrasynovial tendons repopulated with intrasynovial tenocytes. These constructs grossly resemble normal intrasynovial tendons, and cells were found both on the surface and the core of the construct histologically. This new construct represents an important first step in developing a viable tissue-engineered flexor tendon.
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Affiliation(s)
- Andrew Y Zhang
- Division of Plastic Surgery, Stanford University Hospital and Clinics, 770 Welch Rd, Suite 400, Stanford, CA 94304, USA.
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26
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Zhang F, Zhang AY, Li P. Dependence of Cathepsin L –induced Coronary Endothelial Dysfunction upon Activation of NAD(P)H Oxidase. FASEB J 2009. [DOI: 10.1096/fasebj.23.1_supplement.937.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Fan Zhang
- Department of Pharmacology & ToxicologyMedical College of Virginia CampusVirginia Commonwealth UniversityRichmondVA
| | - Andrew Y Zhang
- Department of Pharmacology & ToxicologyMedical College of Virginia CampusVirginia Commonwealth UniversityRichmondVA
| | - Pin‐Lan Li
- Department of Pharmacology & ToxicologyMedical College of Virginia CampusVirginia Commonwealth UniversityRichmondVA
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Abstract
Dupuytren's disease is characterised by nodular fibroblastic proliferation of the palmar fascia leading to contracture of the hand. Transforming growth factor beta (TGF-beta) is thought to play a role in its pathogenesis. We performed a cDNA microarray analysis of Dupuytren's diseased cord tissue with an emphasis on TGF-beta isoforms. Normal-appearing transverse ligament of the palmar fascia from adjacent to the diseased cord and palmar fascia from patients undergoing carpal tunnel release were used as controls. TGF-beta gene expression was confirmed by quantitative real-time polymerase chain reaction. Over 20 unique genes were found to be significantly up-regulated, including several previously reported genes. A dominant increase in TGF-beta2 expression was seen in the cord tissue, whereas TGF-beta1 and TGF-beta3 were found not to be significantly up-regulated. Quantitative real-time polymerase chain reaction confirmed these findings. This gene expression profile allows for further experiments that may eventually lead to gene therapy to block the development and progression of Dupuytren's disease clinically.
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Affiliation(s)
- A Y Zhang
- Division of Plastic Surgery, Stanford Hospital and Clinics, Stanford, CA, USA.
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29
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Karnik SK, Chen H, McLean GW, Heit JJ, Gu X, Zhang AY, Fontaine M, Yen MH, Kim SK. Menin controls growth of pancreatic beta-cells in pregnant mice and promotes gestational diabetes mellitus. Science 2007; 318:806-9. [PMID: 17975067 DOI: 10.1126/science.1146812] [Citation(s) in RCA: 251] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
During pregnancy, maternal pancreatic islets grow to match dynamic physiological demands, but the mechanisms regulating adaptive islet growth in this setting are poorly understood. Here we show that menin, a protein previously characterized as an endocrine tumor suppressor and transcriptional regulator, controls islet growth in pregnant mice. Pregnancy stimulated proliferation of maternal pancreatic islet beta-cells that was accompanied by reduced islet levels of menin and its targets. Transgenic expression of menin in maternal beta-cells prevented islet expansion and led to hyperglycemia and impaired glucose tolerance, hallmark features of gestational diabetes. Prolactin, a hormonal regulator of pregnancy, repressed islet menin levels and stimulated beta-cell proliferation. These results expand our understanding of mechanisms underlying diabetes pathogenesis and reveal potential targets for therapy in diabetes.
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Affiliation(s)
- Satyajit K Karnik
- Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
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30
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Yi F, Zhang AY, Li N, Zhang F, Xia M, Li PL. Role of cyclic ADP-ribose-Ca2+ signaling in mediating renin production and release in As4.1 cells. Cell Physiol Biochem 2007; 19:293-302. [PMID: 17495469 DOI: 10.1159/000100648] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/13/2006] [Indexed: 11/19/2022] Open
Abstract
The present study was designed to test the hypothesis that cyclic-ADP-ribose (cADPR) serves as a novel second messenger to mediate intracellular Ca(2+) concentration in As4.1 cells, a prototype of renal juxtaglomerular cells, and thereby regulates the renin production and release. Western blot analysis showed that CD38, an enzyme responsible for the production of cADPR, was abundant in As4.1 cells. Using cADPR cycling assay, it was found that NaCl stimulated cADPR production in these cells, which was blocked by inhibition of ADP-ribosyl cyclase with nicotinamide. HPLC analysis showed that the conversion rate of beta-NGD into cGDPR was dramatically increased by NaCl, which was attenuated by nicotinamide. Using fluorescent microscopic imaging analysis, NaCl (100 mM) was demonstrated to stimulate a rapid Ca(2+) increase from the endoplasmic reticulum (ER), which was inhibited by a cADPR antagonist, 8-bromo-cADPR (30 microM), an inhibitor of ADP-ribosyl cyclase, nicotinamide (6 mM), the ryanodine receptors blocker, ryanodine (30 microM), or a Ca(2+)-induced Ca(2+) release inhibitor, tetracaine (10 microM) by 70-90%. Finally, NaCl was found to significantly lower the renin production and release levels in As4.1 cells, which was accompanied by decreases in renin mRNA levels. Pretreatment of these cells with various inhibitors or blockers above significantly blocked the inhibitory effect of NaCl on renin production and release. These results indicate that cADPR-mediated Ca(2+) signaling pathway is present in As4.1 cells and that this signaling pathway may play a contributing role in the regulation of renin production and release.
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Affiliation(s)
- Fan Yi
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, USA.
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Zhang AY, Yi F, Jin S, Xia M, Chen QZ, Gulbins E, Li PL. Acid sphingomyelinase and its redox amplification in formation of lipid raft redox signaling platforms in endothelial cells. Antioxid Redox Signal 2007; 9:817-28. [PMID: 17508908 DOI: 10.1089/ars.2007.1509] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This study examined the role of acid sphingomyelinase (ASM) and its redox amplification in mediating the formation of lipid raft (LR) redox signaling platforms in coronary arterial endothelial cells (CAECs). Using small interference RNA (siRNA) of ASM, Fas ligand (FasL)-induced increase in ASM activity, production of ceramide, and LR clustering in CAECs were blocked, and clustered Fas was also substantially reduced in detergent-resistant membrane fractions of CAECs. LR clustering, gp91(phox) aggregation, and p47(phox) translocation to the LR clusters induced by FasL were also blocked in ASM-siRNA transfected CAECs. Corresponding to this reduction of LR clustering with NAD(P)H oxidase subunits in ASM-siRNA transfected CAECs, superoxide (O(2)(-*)) production was significantly decreased as measured by either ESR or fluorescent spectrometry. Interestingly, superoxide dismutase (SOD) not only scavenged (O(2)(-*)), but also markedly attenuated LR clustering. Xanthine/xanthine oxidase, an exogenous (O(2)(-*)) generating system, dramatically increased ASM activity and LR clustering in EC membrane and enhanced FasL-induced LR clustering, which were blocked by SOD. These results suggest that that ASM activates LR clustering to form redox signaling platforms, where (O(2)(-*)) production enhances ASM activity, and thereby results in a forwarding amplification of LR and redox signaling. This ASM-mediated feedforwarding mechanism may be critical for an efficient transmembrane signaling through LRs.
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Affiliation(s)
- Andrew Y Zhang
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298, USA
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Bates SJ, Morrow E, Zhang AY, Pham H, Longaker MT, Chang J. Mannose-6-phosphate, an inhibitor of transforming growth factor-beta, improves range of motion after flexor tendon repair. J Bone Joint Surg Am 2006; 88:2465-72. [PMID: 17079405 DOI: 10.2106/jbjs.e.00143] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Adhesion formation between the flexor tendon and its surrounding fibro-osseous sheath results in a decreased postoperative range of motion in the hand. Transforming growth factor-beta (TGF-beta) is a key cytokine in the pathogenesis of tissue fibrosis. In this study, the effects of two natural inhibitors of TGF-beta, decorin and mannose-6-phosphate, were investigated in vitro and in vivo. METHODS In the in vitro investigation, primary cell cultures from rabbit flexor tendon sheath, epitenon, and endotenon were established and each was supplemented with TGF-beta along with increasing doses of decorin or mannose-6-phosphate. Collagen-I production was measured with enzyme-linked immunosorbent assay (ELISA). For the in vivo study, rabbit zone-II flexor tendons were transected and then immediately repaired. Single intraoperative graded doses of decorin, mannose-6-phosphate, or phosphate-buffered saline solution (control) were added to the repair sites, and the forepaws were tested for the range of motion and repair strength at eight weeks postoperatively. RESULTS Decorin and mannose-6-phosphate both reduced TGF-beta upregulated collagen production. Intraoperative application of low-dose mannose-6-phosphate significantly improved the range of motion of the operatively treated digits. The effect on breaking strength of the tendon repair was inconclusive. CONCLUSIONS Mannose-6-phosphate is effective in reducing TGF-beta upregulated collagen production in an in vitro model. This finding correlated with our in vivo finding that a single intraoperative dose of mannose-6-phosphate improved the postoperative range of motion.
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Affiliation(s)
- Steven J Bates
- Stanford University Medical Center, 770 Welch Road, Suite 400, Stanford, CA 94304, USA
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33
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Abstract
Cyclic ADP-ribose (cADPR) is a novel Ca(2+) mobilizing second messenger, which is capable of inducing Ca(2+) release from the sarcoplasmic reticulum (SR) via activation of ryanodine receptors (RyR) in vascular cells. This signaling nucleotide has also been reported to participate in generation or modulation of intracellular Ca(2+) sparks, Ca(2+) waves or oscillations, Ca(2+)- induced Ca(2+) release (CICR) and spontaneous transient outward currents (STOCs) in vascular smooth muscle cells (VSMCs). With respect to the role of cADPR-mediated signaling in mediation of vascular responses to different stimuli, there is accumulating evidence showing that cADPR is importantly involved in the Ca(2+) response of vascular endothelial cells (ECs) and VSMCs to various chemical factors such as vasoactive agonists acetylcholine, oxotremorine, endothelin, and physical stimuli such as stretch, electrical depolarization and sheer stress. This cADPR-RyR-mediated Ca(2+) signaling is now recognized as a fundamental mechanism regulating vascular function. Here we reviewed the literature regarding this cADPR signaling pathway in vascular cells with a major focus on the production of cADPR and its physiological roles in the control of vascular tone and vasomotor response. We also summarized some publish results that unveil the underlying mechanisms mediating the actions of cADPR in vascular cells. Given the importance of Ca(2+) in the regulation of vascular function, the results summarized in this brief review will provide new insights into vascular physiology and circulatory regulation.
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Affiliation(s)
- Andrew Y Zhang
- Department of Pharmacology & Toxicology, Medical College of Virginia, Virginia Commonwealth UniversityVA, USA
| | - Pin - Lan Li
- Department of Pharmacology & Toxicology, Medical College of Virginia, Virginia Commonwealth UniversityVA, USA
- * Correspondence to: Pin-Lan LI, M.D, Ph.D. Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, 410 N 12th, Richmond, VA 23298, USA. Tel.: (804) 828-4793; Fax: (804) 828-2117 E-mail:
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Yi F, Zhang AY, Li N, Muh RW, Fillet M, Renert AF, Li PL. Inhibition of ceramide-redox signaling pathway blocks glomerular injury in hyperhomocysteinemic rats. Kidney Int 2006; 70:88-96. [PMID: 16688115 DOI: 10.1038/sj.ki.5001517] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Ceramide-activated NAD(P)H oxidase has been reported to participate in homocysteine (Hcys)-induced abnormal metabolism of the extracellular matrix (ECM) in rat glomerular mesangial cells. However, it remains unknown whether this ceramide-redox signaling pathway contributes to glomerular injury induced by hyperhomocysteinemia (hHcys) in vivo. The present study was designed to address this question, defining the role of ceramide and activated NAD(P)H oxidase in the development of hHcys-induced glomerular injury. Uninephrectomized Sprague-Dawley rats were fed a folate-free diet for 8 weeks to produce hHcys and the de novo ceramide synthesis inhibitor myriocin or the NAD(P)H oxidase inhibitor apocynin was administrated. Rats with folate-free diet significantly increased plasma Hcys levels, renal ceramide levels, and NAD(P)H oxidase activity accompanied by marked glomerular injury. Treatment of rats with myriocin significantly reduced ceramide levels and improved glomerular injury, as shown by decreased urinary albumin excretion and reduced glomerular damage index. ECM components changed towards to normal levels with decreased tissue inhibitor of metalloproteinase-1 and increased matrix metalloproteinase-1 activity. NAD(P)H oxidase activity and Rac GTPase activity were reduced by 69 and 66%, respectively. In rats treated with apocynin, similar beneficial effects in protecting glomeruli from hHcys-induced injury were observed. These results support the view that de novo ceramide production is involved in Hcys-induced NAD(P)H oxidase activity in the kidney of hHcys rats and indicate the important role of ceramide-mediated redox signaling in hHcys-induced glomerular injury in rats.
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Affiliation(s)
- F Yi
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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35
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Zhang AY, Zhang G, Li VX, Teggatz EG, Li P. NADPH OXIDASE‐MEDIATED O
2
−·
PRODUCTION AMPLIFIES VASOCONSTRICTOR RESPONSE OF SMALL CORONARY ARTERIES TO M
1
‐MUSCARINIC RECEPTOR ACTIVATION. FASEB J 2006. [DOI: 10.1096/fasebj.20.4.a723-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Andrew Y Zhang
- Pharmacology & ToxicologyMedical College of VirginiaVirginia Commonwealth University410 N 12thRichmondVA23298
| | - Guo Zhang
- Pharmacology & ToxicologyMedical College of VirginiaVirginia Commonwealth University410 N 12thRichmondVA23298
| | - Victoria X. Li
- Pharmacology & ToxicologyMedical College of VirginiaVirginia Commonwealth University410 N 12thRichmondVA23298
| | - Eric G. Teggatz
- Pharmacology & ToxicologyMedical College of VirginiaVirginia Commonwealth University410 N 12thRichmondVA23298
| | - Pin‐Lan Li
- Pharmacology & ToxicologyMedical College of VirginiaVirginia Commonwealth University410 N 12thRichmondVA23298
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Zhang F, Zhang G, Zhang AY, Koeberl MJ, Wallander E, Li PL. Production of NAADP and its role in Ca2+ mobilization associated with lysosomes in coronary arterial myocytes. Am J Physiol Heart Circ Physiol 2006; 291:H274-82. [PMID: 16473958 DOI: 10.1152/ajpheart.01064.2005] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study was designed to determine the production of nicotinic acid adenine dinucleotide phosphate (NAADP) and its role associated with lysosomes in mediating endothelin-1 (ET-1)-induced vasoconstriction in coronary arteries. HPLC assay showed that NAADP was produced in coronary arterial smooth muscle cells (CASMCs) via endogenous ADP-ribosyl cyclase. Fluorescence microscopic analysis of intracellular Ca2+ concentration ([Ca2+]i) in CASMCs revealed that exogenous 100 nM NAADP increased [Ca2+]i by 711 +/- 47 nM. Lipid bilayer experiments, however, demonstrated that NAADP did not directly activate ryanodine (Rya) receptor Ca2+ release channels on the sarcoplasmic reticulum. In CASMCs pretreated with 100 nM bafilomycin A1 (Baf), an inhibitor of lysosomal Ca2+ release and vacuolar proton pump function, NAADP-induced [Ca2+]i increase was significantly abolished. Moreover, ET-1 significantly increased NAADP formation in CASMCs and resulted in the rise of [Ca2+]i in these cells with a large increase in global Ca2+ level of 1,815 +/- 84 nM. Interestingly, before this large Ca2+ increase, a small Ca2+ spike with an increase in [Ca2+]i of 529 +/- 32 nM was observed. In the presence of Baf (100 nM), this ET-1-induced two-phase [Ca2+]i response was completely abolished, whereas Rya (50 microM) only markedly blocked the ET-1-induced large global Ca2+ increase. Functional studies showed that 100 nM Baf significantly attenuated ET-1-induced maximal constriction from 82.26 +/- 4.42% to 51.80 +/- 4.36%. Our results suggest that a lysosome-mediated Ca2+ regulatory mechanism via NAADP contributes to ET-1-induced Ca2+ mobilization in CASMCs and consequent vasoconstriction of coronary arteries.
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Affiliation(s)
- Fan Zhang
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA 23298, USA
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37
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Lee LC, Zhang AY, Chong AK, Pham H, Longaker MT, Chang J. Expression of a novel gene, MafB, in Dupuytren's disease. J Hand Surg Am 2006; 31:211-8. [PMID: 16473681 DOI: 10.1016/j.jhsa.2005.09.007] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2005] [Revised: 09/17/2005] [Accepted: 09/29/2005] [Indexed: 02/02/2023]
Abstract
PURPOSE Dupuytren's disease (DD) is characterized by fibroblastic proliferation of the palmar fascia, often leading to flexion contracture in the hand. Although there is a strong genetic component the genome-wide expression of novel genes is not known. The purpose of this study was to use DNA microarray technology to identify upregulated genes in DD. METHODS Human tissue samples were harvested from 3 patient sources: DD cord tissue (n = 20), normal-appearing adjacent control fascia (n = 15), and palmar fascia from patients having carpal tunnel release (n = 15). DNA microarray analysis was performed on amplified sample RNA. Novel genes were compared with known gene functions. A candidate gene of interest was studied further by using immunohistochemistry on DD tissue samples and controls. RESULTS Several novel genes not described previously in the study of DD were upregulated significantly, including MafB, collagen type V, alpha-2 (COL5A2), collagen type VIII, alpha-1 (COL8A1), contactin I (CNTN1), and leucine-rich repeat containing 17 (LRRC17). These upregulated genes were compared with their known gene-expression profiles in other tissues and their purported functions. MafB was found to be of particular interest because of its prominent role in tissue development and cellular differentiation. MafB immunohistochemistry showed positive staining in 50% of the DD specimens but complete absence of MafB in all control tissues (adjacent control fascia, carpal tunnel fascia). Co-localization experiments with MafB and alpha-smooth muscle actin showed staining properties in similar regions but these 2 proteins were not confined solely to the same cells. CONCLUSIONS Microarray analysis of DD tissue has identified significant upregulated gene expression of MafB. MafB protein also is found in Dupuytren's cords but not in control fascia. Co-localization data suggest that the association of MafB with DD is not related exclusively to myofibroblast proliferation. Because of its role in fibroblastic transformation in other models MafB and its relationship to the pathogenesis of DD deserves further study.
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Affiliation(s)
- Lucy C Lee
- Stanford University School of Medicine, Stanford, CA, USA
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38
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Abstract
Recent studies have indicated that lipid rafts (LRs) in the cell membrane are clustered in response to different stimuli to form signaling platforms for transmembrane transduction. It remains unknown whether this LR clustering participates in redox signaling in endothelial cells. The present study tested a hypothesis that clustering of LRs on the membrane of coronary endothelial cells produces aggregation and activation of reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase, thereby forming a redox signaling platform. By confocal microscopic analysis of agonist-stimulated rafts patch formation, we found that several death receptor ligands or apoptotic factors, including tumor necrosis factor α, Fas ligand, or endostatin, stimulated the clustering and trafficking of individual LRs on the plasma membrane of coronary endothelial cells. Interestingly, double labeling of a membrane-bound NADPH oxidase subunit, gp91
phox
, and LRs showed that gp91
phox
colocalized within the LR patches when endothelial cells were stimulated by Fas ligand. In isolated LR fractions from Fas-stimulated endothelial cells, gp91
phox
, p47
phox
(a crucial cytosolic regulatory subunit of NADPH oxidase), and Rac GTPase were markedly increased and blocked by nystatin, a compound that disrupts LRs. These clustered LRs contained high NADPH oxidase activity, which increased in response to Fas stimulation. Functionally, Fas ligand–induced inhibition of endothelium-dependent vasorelaxation was reduced if LRs were disrupted or NADPH oxidase was inhibited. These results suggest that LR clustering occurs in coronary endothelial cells. The formation of redox signaling platforms on the cell membrane mediates transmembrane signaling of death receptors, resulting in endothelial dysfunction.
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Affiliation(s)
- Andrew Y. Zhang
- From the Department of Pharmacology and Toxicology (A.Y.Z., F.Y., P-L.L.), Medical College of Wisconsin, Milwaukee; Department of Pharmacology and Toxicology (G.Z.), Medical College of Virginia, Virginia Commonwealth University, Richmond; and Department of Molecular Biology (E.G.), University of Essen, Germany
| | - Fan Yi
- From the Department of Pharmacology and Toxicology (A.Y.Z., F.Y., P-L.L.), Medical College of Wisconsin, Milwaukee; Department of Pharmacology and Toxicology (G.Z.), Medical College of Virginia, Virginia Commonwealth University, Richmond; and Department of Molecular Biology (E.G.), University of Essen, Germany
| | - Guo Zhang
- From the Department of Pharmacology and Toxicology (A.Y.Z., F.Y., P-L.L.), Medical College of Wisconsin, Milwaukee; Department of Pharmacology and Toxicology (G.Z.), Medical College of Virginia, Virginia Commonwealth University, Richmond; and Department of Molecular Biology (E.G.), University of Essen, Germany
| | - Erich Gulbins
- From the Department of Pharmacology and Toxicology (A.Y.Z., F.Y., P-L.L.), Medical College of Wisconsin, Milwaukee; Department of Pharmacology and Toxicology (G.Z.), Medical College of Virginia, Virginia Commonwealth University, Richmond; and Department of Molecular Biology (E.G.), University of Essen, Germany
| | - Pin-Lan Li
- From the Department of Pharmacology and Toxicology (A.Y.Z., F.Y., P-L.L.), Medical College of Wisconsin, Milwaukee; Department of Pharmacology and Toxicology (G.Z.), Medical College of Virginia, Virginia Commonwealth University, Richmond; and Department of Molecular Biology (E.G.), University of Essen, Germany
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39
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Abstract
Recent studies have indicated that lipid rafts (LRs) in the cell membrane are clustered in response to different stimuli to form signaling platforms for transmembrane transduction. It remains unknown whether this LR clustering participates in redox signaling in endothelial cells. The present study tested a hypothesis that clustering of LRs on the membrane of coronary endothelial cells produces aggregation and activation of reduced nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase, thereby forming a redox signaling platform. By confocal microscopic analysis of agonist-stimulated rafts patch formation, we found that several death receptor ligands or apoptotic factors, including tumor necrosis factor alpha, Fas ligand, or endostatin, stimulated the clustering and trafficking of individual LRs on the plasma membrane of coronary endothelial cells. Interestingly, double labeling of a membrane-bound NADPH oxidase subunit, gp91phox, and LRs showed that gp91phox colocalized within the LR patches when endothelial cells were stimulated by Fas ligand. In isolated LR fractions from Fas-stimulated endothelial cells, gp91phox, p47phox (a crucial cytosolic regulatory subunit of NADPH oxidase), and Rac GTPase were markedly increased and blocked by nystatin, a compound that disrupts LRs. These clustered LRs contained high NADPH oxidase activity, which increased in response to Fas stimulation. Functionally, Fas ligand-induced inhibition of endothelium-dependent vasorelaxation was reduced if LRs were disrupted or NADPH oxidase was inhibited. These results suggest that LR clustering occurs in coronary endothelial cells. The formation of redox signaling platforms on the cell membrane mediates transmembrane signaling of death receptors, resulting in endothelial dysfunction.
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Affiliation(s)
- Andrew Y Zhang
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, USA
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40
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Zhang G, Teggatz EG, Zhang AY, Koeberl MJ, Yi F, Chen L, Li PL. Cyclic ADP ribose-mediated Ca2+ signaling in mediating endothelial nitric oxide production in bovine coronary arteries. Am J Physiol Heart Circ Physiol 2005; 290:H1172-81. [PMID: 16243917 DOI: 10.1152/ajpheart.00441.2005] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study tested the hypothesis that cyclic ADP ribose (cADPR) serves as a novel second messenger to mediate intracellular Ca2+ mobilization in coronary arterial endothelial cells (CAECs) and thereby contributes to endothelium-dependent vasodilation. In isolated and perfused small bovine coronary arteries, bradykinin (BK)-induced concentration-dependent vasodilation was significantly attenuated by 8-bromo-cADPR (a cell-permeable cADPR antagonist), ryanodine (an antagonist of ryanodine receptors), or nicotinamide (an ADP-ribosyl cyclase inhibitor). By in situ simultaneously fluorescent monitoring, Ca2+ transient and nitric oxide (NO) levels in the intact coronary arterial endothelium preparation, 8-bromo-cADPR (30 microM), ryanodine (50 microM), and nicotinamide (6 mM) substantially attenuated BK (1 microM)-induced increase in intracellular [Ca2+] by 78%, 80%, and 74%, respectively, whereas these compounds significantly blocked BK-induced NO increase by about 80%, and inositol 1,4,5-trisphosphate receptor blockade with 2-aminethoxydiphenyl borate (50 microM) only blunted BK-induced Ca2+-NO signaling by about 30%. With the use of cADPR-cycling assay, it was found that inhibition of ADP-ribosyl cyclase by nicotinamide substantially blocked BK-induced intracellular cADPR production. Furthermore, HPLC analysis showed that the conversion rate of beta-nicotinamide guanine dinucleotide into cyclic GDP ribose dramatically increased by stimulation with BK, which was blockable by nicotinamide. However, U-73122, a phospholipase C inhibitor, had no effect on this BK-induced increase in ADP-ribosyl cyclase activity for cADPR production. In conclusion, these results suggest that cADPR importantly contributes to BK- and A-23187-induced NO production and vasodilator response in coronary arteries through its Ca2+ signaling mechanism in CAECs.
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Affiliation(s)
- Guo Zhang
- Department of Pharmacology and Toxicology, Medical College of Virginia, Virginia Commonwealth University, 410 N 12th St., Richmond, Virginia 23298, USA
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41
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Teggatz EG, Zhang G, Zhang AY, Yi F, Li N, Zou AP, Li PL. Role of cyclic ADP-ribose in Ca2+-induced Ca2+ release and vasoconstriction in small renal arteries. Microvasc Res 2005; 70:65-75. [PMID: 16095628 DOI: 10.1016/j.mvr.2005.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Revised: 06/23/2005] [Accepted: 06/29/2005] [Indexed: 11/23/2022]
Abstract
Cyclic-ADP-ribose (cADPR) has been reported to serve as a second messenger to mobilize intracellular Ca2+ independent of IP3 in a variety of mammalian cells. This cADPR-mediated Ca2+ signaling pathway importantly participates in the regulation of various cell functions. The present study determined the role of endogenous cADPR in mediating ryanodine-sensitive Ca2+-induced Ca2+ release (CICR) in vascular myocytes from small renal arteries and vasomotor response of these arteries. In freshly-isolated renal arterial myocytes, addition of CaCl2 (0.01, 0.1, and 1 mM) into the Ca2+-free bath solution produced a rapid Ca2+ release response from the sarcoplasmic reticulum (SR), with a maximal increase of 237+/-25 nM at 1 mM CaCl2. This CaCl2 response was significantly blocked by a cell-membrane permeant cADPR antagonist, 8-bromo-cADP-ribose (8-br-cADPR) (30 microM) or ryanodine (50 microM). Caffeine, a classical CICR or ryanodine receptor activator was found to stimulate the SR Ca2+ release (Delta[Ca2+]i: 253+/-35 nM), which was also attenuated by 8-br-cADPR or ryanodine. Using isolated and pressurized small renal arteries bathed with Ca2+-free solution, both CaCl2 and caffeine-induced vasoconstrictions were significantly attenuated by either 8-br-cADPR or ryanodine. Biochemical analyses demonstrated that CaCl2 and caffeine did not increase cADPR production in these renal arterial myocytes, but confocal microscopy showed that a dissociation of the accessory protein, FK506 binding protein 12.6 (FKBP12.6) from ryanodine receptors was induced by CaCl2. We conclude that cADPR importantly contributes to CICR and vasomotor responses of small renal arteries through enhanced dissociation of ryanodine receptors from their accessory protein.
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Affiliation(s)
- Eric G Teggatz
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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42
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Abstract
BACKGROUND We recently demonstrated that homocysteine (Hcys) increases superoxide (O2-) production via NADH/NADPH oxidase in renal mesangial cells. This O2- production contributes to increased expression of tissue inhibitor of metalloproteinase (TIMP-1) and consequent deposition of collagen in response to Hcys. However, the mechanism by which Hcys activates NADH/NADPH oxidase remains unknown. Given that ceramide is an intracellular activator of this oxidase in several cell types, the present study tests the hypothesis that Hcys activates NADH/NADPH oxidase through a ceramide-mediated signaling pathway in rat mesangial (MG) cells, resulting in O2- production. METHODS Rat MG cells were incubated with L-homocysteine (L-Hcys) to determine the mechanism by which Hcys activates NADH/NADPH oxidase. Thin layer chromatography (TLC), Western blot analysis, Rac GTPase activity pull down assay, and NADH/NADPH oxidase activity measurements were performed. RESULTS TLC analysis demonstrated that L-Hcys increased de novo production of ceramide in MG cells. L-Hcys and increased ceramide did not alter the amount of NADH/NADPH oxidase subunit p47phox and p67phox in both membrane and cytosolic fractions from MG cells. However, L-Hcys or ceramide markedly increased the level of GTP-bound Rac, which was accompanied by enhanced activity of NADH/NADPH oxidase. These Hcys or ceramide-induced actions were substantially blocked by a Rac GTPase inhibitor, GDPbetaS, and a de novo ceramide synthesis inhibitor, fumonisin B1 (FB1). CONCLUSION These results indicate that Hcys activates NADH/NADPH oxidase by stimulating de novo ceramide synthesis, and subsequently enhancing Rac GTPase activity in rat MG cells. This ceramide-Rac GTPase signaling pathway may mediate Hcys-induced oxidative stress in these glomerular cells.
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Affiliation(s)
- Fan Yi
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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Zhang AY, Yi F, Teggatz EG, Zou AP, Li PL. Enhanced production and action of cyclic ADP-ribose during oxidative stress in small bovine coronary arterial smooth muscle. Microvasc Res 2004; 67:159-67. [PMID: 15020207 DOI: 10.1016/j.mvr.2003.11.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2003] [Indexed: 11/28/2022]
Abstract
Recent studies in our lab and by others have indicated that cyclic ADP-ribose (cADPR) as a novel second messenger is importantly involved in vasomotor response in various vascular beds. However, the mechanism regulating cADPR production and actions remains poorly understood. The present study determined whether changes in redox status influence the production and action of cADPR in coronary arterial smooth muscle cells (CASMCs) and thereby alters vascular tone in these arteries. HPLC analyses demonstrated that xanthine (X, 40 microM)/xanthine oxidase (XO, 0.1 U/ml), a superoxide-generating system, increased the ADP-ribosyl cyclase activity by 59% in freshly isolated bovine CASMCs. However, hydrogen peroxide (H2O2, 1-100 microM) had no significant effect on ADP-ribosyl cyclase activity. In these CASMCs, X/XO produced a rapid increase in [Ca2+]i (Delta[Ca2+]i=201 nM), which was significantly attenuated by a cADPR antagonist, 8-Br-cADPR. Both inhibition of cADPR production by nicotinamide (Nicot) and blockade of Ca2+-induced Ca2+ release (CICR) by tetracaine (TC) and ryanodine (Rya) significantly reduced X/XO-induced rapid Ca2+ responses. In isolated, perfused, and pressurized small bovine coronary arteries, X at 2.5-80 microM with a fixed XO level produced a concentration-dependent vasoconstriction with a maximal decrease in arterial diameter of 45%. This X/XO-induced vasoconstriction was significantly attenuated by 8-Br-cADPR, Nicot, TC, or Rya. We conclude that superoxide activates cADPR production, and thereby mobilizes intracellular Ca2+ from the SR and produces vasoconstriction in coronary arteries.
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Affiliation(s)
- Andrew Y Zhang
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Zhang AY, Teggatz EG, Zou AP, Campbell WB, Li PL. Endostatin uncouples NO and Ca2+ response to bradykinin through enhanced O2*- production in the intact coronary endothelium. Am J Physiol Heart Circ Physiol 2004; 288:H686-94. [PMID: 15471985 DOI: 10.1152/ajpheart.00174.2004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The present study tested the hypothesis that endostatin stimulates superoxide (O2*-) production through a ceramide-mediating signaling pathway and thereby results in an uncoupling of bradykinin (BK)-induced increases in intracellular Ca2+ concentration ([Ca2+]i) from nitric oxide (NO) production in coronary endothelial cells. With the use of high-speed, wavelength-switching, fluorescence-imaging techniques, the [Ca2+]i and NO levels were simultaneously monitored in the intact endothelium of freshly isolated bovine coronary arteries. Under control conditions, BK was found to increase NO production and [Ca2+]i in parallel. When the arteries were pretreated with 100 nM human recombinant endostatin for 1 h, this BK-induced NO production was reduced by 89%, whereas [Ca2+]i was unchanged. With the conversion rate of L-[3H]arginine to L-[3H]citrulline measured, endostatin had no effect on endothelial NO synthase (NOS) activity, but it stimulated ceramide by activation of sphingomyelinase (SMase), whereby O2*-. production was enhanced in endothelial cells. O2*-. scavenging by tiron and inhibition of NAD(P)H oxidase by apocynin markedly reversed the effect of endostatin on the NO response to BK. These results indicate that endostatin increases intracellular ceramide levels, which enhances O2*-. production through activation of NAD(P)H oxidase. This ceramide-O2*-. signaling pathway may contribute importantly to endostatin-induced endothelial dysfunction.
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Affiliation(s)
- Andrew Y Zhang
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA
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45
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Chen YF, Zhang AY, Zou AP, Campbell WB, Li PL. Protein Methylation Activates Reconstituted Ryanodine Receptor-Ca 2+ Release Channels from Coronary Artery Myocytes. J Vasc Res 2004; 41:229-40. [PMID: 15118362 DOI: 10.1159/000078178] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2002] [Accepted: 01/27/2004] [Indexed: 11/19/2022] Open
Abstract
Ryanodine receptors (RyR) play an important role in the regulation of intracellular Ca(2+) concentration and in the control of vascular tone. However, the mechanism regulating the activity of RyR is poorly understood. The present study determined whether protein methylation participates in the control of RyR activity. Using a planar lipid bilayer clamping system, S-adenosyl-L-methionine (SAM), a methyl donor, significantly increased the activity of a 245-pS reconstituted Ca(2+) release channel from coronary arterial smooth muscle (CASM) in a concentration-dependent manner. Addition of the protein methylation blockers, 3-deazaadenosine, S-adenosylhomocysteine or sinefungin into the cis solution markedly attenuated SAM-induced activation of RyR/Ca(2+) release channels. By Western blot analysis, arginine N-methyltransferase (PRMT1) and FK506 binding protein (FKBP) were detected in the SR used for reconstitution of RyR. In the presence of anti-PRMT1 antibody (1:100), SAM-induced activation of RyR/Ca(2+) channel was completely abolished. In addition, this SAM-induced increase in RyR/Ca(2+) channel activity was blocked by 30 microM ryanodine and by FK506 (100 microM), a ligand for the RyR accessory protein. These results suggest that protein methylation activates RyR/Ca(2+) release channels and may participate in the control of intracellular Ca(2+) mobilization in CASM cells by transferring a methyl group to the arginine moiety of the RyR accessory protein, FKBP 12.
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Affiliation(s)
- Ya-Fei Chen
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee 53226, USA
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46
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Zhang AY, Pham H, Ho F, Teng K, Longaker MT, Chang J. Inhibition of TGF-beta-induced collagen production in rabbit flexor tendons. J Hand Surg Am 2004; 29:230-5. [PMID: 15043894 DOI: 10.1016/j.jhsa.2003.11.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2003] [Revised: 11/03/2003] [Accepted: 11/03/2003] [Indexed: 02/02/2023]
Abstract
PURPOSE Postoperative adhesions frequently compromise the success of flexor tendon repair. Manipulation of growth factors responsible for scar formation may be a method of decreasing adhesion formation. Transforming growth factor beta (TGF-beta) is a key cytokine in the pathogenesis of tissue fibrosis. The purpose of this study was to examine the effectiveness of TGF-beta neutralizing antibody in blocking TGF-beta-induced collagen I production in rabbit flexor tendons in vitro. METHODS Sheath fibroblasts, epitenon tenocytes, and endotenon tenocytes were obtained from rabbit flexor tendons. Each cell culture was supplemented with 1 ng/mL of TGF-beta along with increasing doses of TGF-beta neutralizing antibody (0.1-2.0 microg/mL). Collagen I production was measured by enzyme-linked immunoabsorbent assay and TGF-beta bioactivity was measured by the luciferase assay. Results were compared with TGF-beta alone and unsupplemented controls. RESULTS The addition of neutralizing antibody significantly reduced TGF-beta-induced collagen I production in a dose-dependent manner in all 3 cell cultures. TGF-beta bioactivity was also reduced by its neutralizing antibody. CONCLUSIONS This study shows that TGF-beta inhibition through its neutralizing antibody was effective in cultured flexor tendon cells. The results encourage further experiments that use such agents to modulate flexor tendon wound healing in in vivo models in the hope of eventually blocking the effect of TGF-beta on flexor tendons clinically.
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Affiliation(s)
- Andrew Y Zhang
- Division of Plastic Surgery, Stanford University Medical Center, 770 Welch Road, Stanford, CA 94305, USA
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47
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Abstract
This study examines self-perceived physical and mental health among 213 Chinese elderly who visited the Geriatric Outpatient Clinic of Beijing Hospital, the People's Republic of China. The study hypothesizes that cultural factors, specified by family relations, along with demographic factors, number of diseases, economic well-being, and living conditions have a significant impact on subjects self-perceived health status. Pearson correlation, linear and logistic regression analyses are performed. Results indicate that age, number of diseases, perceived family respect, neighborhood relations, and percentage of income spent on rent are significant predictors of self-perceived physical health. These same factors plus preference to live with a son and personal monthly income are significant predictors of self-perceived mental health. Socio-cultural implications of these findings are examined.
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Affiliation(s)
- L C Yu
- Department of Health Policy and Administration, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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48
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Abstract
The present study examined correlates of life satisfaction among 350 Chinese elderly aged 65 or older. Subjects consisted of a clinic sample (n = 200) and a randomly selected community sample (n = 150) recruited from the same area in Beijing. Linear regression analysis was performed, using health, financial status, and family support as independent variables. Results showed that the regression model explained 38 percent of the variance in life satisfaction in the total sample, 34 percent and 43 percent of the variance respectively in the clinical and community samples. Life satisfaction was significantly predicted by health and financial status among community elderly and by health, financial status, as well as family support among outpatient elderly. Findings suggest that the socio-cultural context has exerted important impacts on the Chinese elderly's life satisfaction.
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Affiliation(s)
- A Y Zhang
- School of Public Health, University of California at Berkeley, 94720-7360, USA.
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49
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Abstract
Despite technical advances in suture methods and rehabilitation protocols, challenges remain in the field of flexor tendon repair. This article reviews the state-of-the-art research in the tissue engineering of flexor tendons. These early published data will hopefully lay the foundation for molecular methods and materials that can be used to reconstruct tendons to restore normal form and function in the hand.
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Affiliation(s)
- Andrew Y Zhang
- Division of Plastic Surgery, Stanford University School of Medicine, NC 104, Stanford, CA 94305, USA
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50
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Zhang AY, Chen YF, Zhang DX, Yi FX, Qi J, Andrade-Gordon P, de Garavilla L, Li PL, Zou AP. Urotensin II is a nitric oxide-dependent vasodilator and natriuretic peptide in the rat kidney. Am J Physiol Renal Physiol 2003; 285:F792-8. [PMID: 12783779 DOI: 10.1152/ajprenal.00342.2002] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Recent studies have indicated that urotensin II (UII), a cyclic peptide, is vasoactive and may be involved in cardiovascular dysfunctions. It remains unknown, however, whether UII plays a role in the control of renal vascular tone and tubular function. In the present study, a continuous infusion of synthetic human UII (hUII) into the renal artery (RA) in anesthetized rats was found to increase renal blood flow (RBF) and urinary water and sodium excretion (UV and UNaV) in a dose-dependent manner. At a dose of 20 ng. kg-1. min-1, it increased RBF by 20% and UV and UNaV by 94 and 109%, respectively. Nitric oxide (NO) synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME) completely abolished hUII-induced increases in RBF and water/sodium excretion. In isolated, pressurized, and phenylephrine-precontracted small RA with internal diameter of approximately 200 microm, hUII produced a concentration-dependent vasodilation with a maximal response of 55% at 1.5 microM. l-NAME significantly blocked this hUII-induced vasodilation by 60%. In denuded RA, hUII had neither vasodilator nor vasoconstrictor effect. With the use of 4,5-diaminofluorescein diacetate-based fluorescence imaging analysis of NO levels, hUII (1 microM) was shown to double the NO levels within the endothelium of freshly dissected small RA, and l-NAME blocked this UII-induced production of endothelial NO. These results indicate that UII produces vasodilator and natriuretic effects in the kidney and that UII-induced vasodilation is associated with increased endothelial NO in the RA.
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Affiliation(s)
- Andrew Y Zhang
- Deptartment of Physiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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