1
|
Groeneveld DC, Leung LKH, Guo Y, Vasic A, El Nakla M, Peng SW, Yang J, Cheng SC. Lookup Tables for Predicting CHF and Film-Boiling Heat Transfer: Past, Present, and Future. NUCL TECHNOL 2017. [DOI: 10.13182/nt152-87] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- D. C. Groeneveld
- Atomic Energy of Canada Limited, Chalk River Laboratories Ontario K0J 1J0, Canada and University of Ottawa Department of Mechanical Engineering, Ottawa, Ontario K1N 6N5, Canada
| | - L. K. H. Leung
- Atomic Energy of Canada Limited Chalk River Laboratories, Ontario K0J 1J0, Canada
| | - Y. Guo
- Atomic Energy of Canada Limited Chalk River Laboratories, Ontario K0J 1J0, Canada
| | - A. Vasic
- Atomic Energy of Canada Limited Chalk River Laboratories, Ontario K0J 1J0, Canada
| | - M. El Nakla
- University of Ottawa, Department of Mechanical Engineering Ottawa, Ontario K1N 6N5, Canada
| | - S. W. Peng
- University of Ottawa, Department of Mechanical Engineering Ottawa, Ontario K1N 6N5, Canada
| | - J. Yang
- University of Ottawa, Department of Mechanical Engineering Ottawa, Ontario K1N 6N5, Canada
| | - S. C. Cheng
- University of Ottawa, Department of Mechanical Engineering Ottawa, Ontario K1N 6N5, Canada
| |
Collapse
|
2
|
Knafl D, Tobudic S, Cheng SC, Bellamy DR, Thalhammer F. Dalbavancin reduces biofilms of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE). Eur J Clin Microbiol Infect Dis 2016; 36:677-680. [PMID: 27896496 PMCID: PMC5366172 DOI: 10.1007/s10096-016-2845-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [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: 08/18/2016] [Accepted: 11/11/2016] [Indexed: 01/29/2023]
Abstract
Activity of dalbavancin against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) in biofilm was investigated and the microbicidal biofilm concentrations (MBC) were determined. Biofilms obtained from ten MRSA and ten MRSE bloodstream isolates, collected from patients in the General Hospital of Vienna between 2012 and 2015, were incubated with dalbavancin in trypticase soy broth (TSB) in serial dilution from 0.0625 mg/l to 256 mg/l using a microtiter plate biofilm model. The plates were incubated for 24 h at 37 ° C and 50% humidity. Biofilms were fixed with 2.5% glutaraldehyde and stained with crystal violet. Subsequently the optical density (OD620) was used to measure the MBC, defined as the concentration of dalbavancin leading to a 50% reduction of biofilm. MBC for MRSA was 1 mg/l–4 mg/l (minimal inhibitory concentrations (MIC) 0.0312 mg/l–0.064 mg/l). MBC for MRSE was 2 mg/l–16 mg/l (MIC 0.023 mg/l–0.0625 mg/l). Dalbavancin successfully reduced MRSA and MRSE in biofilms, and therefore provides a promising option for the treatment of biofilm-associated infections.
Collapse
Affiliation(s)
- D Knafl
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
| | - S Tobudic
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - S C Cheng
- Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - D R Bellamy
- Dunedin School of Medicine, University of Otago, Wellington, New Zealand
| | - F Thalhammer
- Division of Infectious Diseases and Tropical Medicine, Department of Medicine I, Medical University Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria
| |
Collapse
|
3
|
Lago-Hernandez CA, Feldman H, O'Donnell E, Mahal BA, Perez V, Howard S, Rosenthal M, Cheng SC, Nguyen PL, Beard C, D'Amico AV, Sweeney CJ. A refined risk stratification scheme for clinical stage 1 NSGCT based on evaluation of both embryonal predominance and lymphovascular invasion. Ann Oncol 2015; 26:1396-401. [PMID: 25888612 DOI: 10.1093/annonc/mdv180] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 04/07/2015] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Active surveillance is an increasingly accepted approach for managing patients with germ-cell tumors (GCTs) after an orchiectomy. Here we investigate a time-to-relapse stratification scheme for clinical stage 1 (CS1) nonseminoma GCT (NSGCT) patients according to factors associated with relapse and identify a group of patients with a lower frequency and longer time-to-relapse who may require an alternative surveillance strategy. PATIENTS AND METHODS We analyzed 266 CS1 GCT patients from the IRB-approved DFCI GCT database that exclusively underwent surveillance following orchiectomy from 1997 to 2013. We stratified NSGCT patients according to predominance of embryonal carcinoma (EmbP) and lymphovascular invasion (LVI), using a 0, 1, and 2 scoring system. Cox regression and conditional risk analysis were used to compare each NSGCT group to patients in the seminomatous germ-cell tumor (SGCT) category. Median time-to-relapse values were then calculated among those patients who underwent relapse. Relapse-free survival curves were generated using the Kaplan-Meier method. RESULTS Fifty (37%) NSGCT and 20 (15%) SGCT patients relapsed. The median time-to-relapse was 11.5 versus 6.3 months for the SGCT and NSGCT groups, respectively. For NSGCT patients, relapse rates were higher and median time-to-relapse faster with increasing number of risk factors (RFs). Relapse rates (%) and median time-to-relapse (months) were 25%/8.5 months, 41%/6.8 months and 78%/3.8 months for RF0, RF1 and RF2, respectively. We found a statistically significant difference between SGCT and patients with one or two RFs (P < 0.001) but not between SGCT and NSGCT RF0 (P = 0.108). CONCLUSION NSGCT patients grouped by a risk score system based on EmbP and LVI yielded three groups with distinct relapse patterns -and patients with neither EmbP nor LVI appear to behave similar to SGCT.
Collapse
Affiliation(s)
- C A Lago-Hernandez
- Harvard Medical School, Boston Department of Medical Oncology-Genitourinary Division, Dana-Farber Cancer Institute, Boston
| | - H Feldman
- Albert Einstein College of Medicine, New York Department of Medical Oncology-Genitourinary Division, Dana-Farber Cancer Institute, Boston
| | - E O'Donnell
- Department of Medical Oncology-Genitourinary Division, Dana-Farber Cancer Institute, Boston
| | - B A Mahal
- Harvard Medical School, Boston Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston
| | - V Perez
- University of Puerto Rico Medical School, San Juan PR
| | - S Howard
- Departments of Imaging, Dana-Farber Cancer Institute, Boston, USA
| | - M Rosenthal
- Departments of Imaging, Dana-Farber Cancer Institute, Boston, USA
| | - S C Cheng
- Biostatistics/Computational Biology, Dana-Farber Cancer Institute, Boston, USA
| | - P L Nguyen
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston
| | - C Beard
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston
| | - A V D'Amico
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston
| | - C J Sweeney
- Department of Medical Oncology-Genitourinary Division, Dana-Farber Cancer Institute, Boston
| |
Collapse
|
4
|
Chau JYM, Chan WL, Woo SB, Cheng SC, Wong TM, Wong TK, Yen CH, Wong K, Wong WC. Hyaluronic acid instillation following arthroscopic anterior cruciate ligament reconstruction: a double-blinded, randomised controlled study. J Orthop Surg (Hong Kong) 2012; 20:162-5. [PMID: 22933671 DOI: 10.1177/230949901202000205] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
PURPOSE To assess the effect of hyaluronic acid instillation after arthroscopic anterior cruciate ligament (ACL) reconstruction for improving pain, range of movement, and function of the knee. METHODS 28 men and 4 women underwent arthroscopic ACL reconstruction for isolated ACL rupture (partial or complete) and instability after recreational sports injury 2 to 120 months earlier. They were randomised to undergo arthroscopic ACL reconstruction followed by intra-articular viscoseal instillation (13 men and 3 women) or arthroscopic ACL reconstruction alone (15 men and 1 woman). The knee injury osteoarthritis outcome score (for pain, symptoms, activities of daily living, sport and recreation function, and quality of life), range of movement, knee circumference, and analgesic use were assessed on days -1, 1, and 2, and weeks 2, 6 and 12. RESULTS Patient demographics were similar at baseline. At postoperative days 1 and 2, all subscales of the knee injury osteoarthritis outcome score (except for quality of life) were significantly higher in the viscoseal group. At weeks 2, 6, and 12, improvement in both groups equalised. Knee swelling (change in knee circumference) was significantly less in the viscoseal group at days 1 and 2 (p=0.009 and p=0.038, respectively, Mann-Whitney U test). Only one patient in the viscoseal group had a limited range of movement. No patient developed any adverse reaction. CONCLUSION Intra-articular viscoseal instillation improved pain control and swelling 2 days after arthroscopic ACL reconstruction.
Collapse
Affiliation(s)
- Jackie Y M Chau
- Department of Orthopaedics and Traumatology, Kwong Wah Hospital, Kowloon, Hong Kong.
| | | | | | | | | | | | | | | | | |
Collapse
|
5
|
|
6
|
|
7
|
Sivardeen Z, Cheng SC, Buchanan D, Hulse D, Fairbairn KJ, Kemp SPT, Brooks JHM, Wallace WA. Shoulder laxity and traumatic shoulder instability in professional rugby players. Br J Sports Med 2011. [DOI: 10.1136/bjsm.2010.081554.54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
8
|
Ling SKK, Cheng SC, Yen CH. Stonefish envenomation with acute carpal tunnel syndrome. Hong Kong Med J 2009; 15:471-473. [PMID: 19966353] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
Stonefish envenomation is a common marine sting. Although stonefish injuries are commonly sustained during maritime activities, this local delicacy can also be considered a regional occupational hazard for chefs. The availability and consumption of stonefish in local restaurants has increased the risk of acute carpal tunnel syndrome after a stonefish injury. This case report describes acute carpal tunnel syndrome following stonefish envenomation. An excellent recovery was achieved after surgical decompression of the carpal tunnel syndrome. Standard management of stonefish injuries should therefore take into account the possibility that this orthopaedic emergency may complicate the injury.
Collapse
Affiliation(s)
- Samuel K K Ling
- Department of Orthopaedics and Traumatology, Kwong Wah Hospital, 25 Waterloo Road, Kowloon, Hong Kong.
| | | | | |
Collapse
|
9
|
Pang CH, Chan WL, Yen CH, Cheng SC, Woo SB, Choi ST, Hui WK, Mak KH. Comparison of total knee arthroplasty using computer-assisted navigation versus conventional guiding systems: a prospective study. J Orthop Surg (Hong Kong) 2009; 17:170-3. [PMID: 19721145 DOI: 10.1177/230949900901700209] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
PURPOSE To compare knee alignments in total knee arthroplasty (TKA) using computer-assisted navigation versus conventional guiding systems. METHODS Five men and 49 women aged 49 to 79 years underwent TKA for primary osteoarthritis of the knee with varus deformity. All valgus knees were associated with inflammatory arthritis and thus excluded. Computer-assisted navigation was used for the first 35 TKAs, whereas conventional extramedullary tibial and intramedullary femoral guiding systems were used for the next 35 TKAs. The mechanical axis, coronal tibial and femoral angles, sagittal tibial and femoral angles in the 2 groups were compared. RESULTS Sagittal tibial and femoral angles aligned more optimally in TKAs using computer-assisted navigation. In the respective computer-assisted navigation and conventional guiding systems, 33 (94%) and 26 (74%) of the TKAs attained a postoperative mechanical axis of <3 degrees varus/valgus. CONCLUSION Computer-assisted navigation gives a more consistent alignment correction and reduces outliers during implant positioning.
Collapse
Affiliation(s)
- C H Pang
- Department of Orthopaedics and Traumatology, Kwong Wah Hospital, 25 Waterloo Road, Hong Kong.
| | | | | | | | | | | | | | | |
Collapse
|
10
|
Cheng SC, Hulse D, Fairbairn KJ, Clarke M, Wallace WA. Comparison of dynamic ultrasound and stress radiology for assessment of inferior glenohumeral laxity in asymptomatic shoulders. Skeletal Radiol 2008; 37:161-8. [PMID: 18030465 DOI: 10.1007/s00256-007-0401-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 09/12/2007] [Accepted: 09/17/2007] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine the level of agreement between dynamic ultrasound imaging and stress radiography used for the measurement of inferior glenohumeral laxity in asymptomatic shoulders, and to determine the repeatability of the dynamic ultrasound technique. MATERIALS AND METHODS Using a custom-made stress device to apply an inferior displacement force of 90 N, we assessed 20 asymptomatic male subjects for inferior glenohumeral laxity, using stress radiography and dynamic ultrasound. Paired differences between the two methods were evaluated by the 95% limits of agreement method. At a separate session, 19 subjects had inferior glenohumeral laxity assessed by two observers, using dynamic ultrasound. Inter- and intra-observer repeatability was determined for the ultrasound technique. RESULTS The mean [(+/-standard deviation (SD)] inferior translation was 4.7+/-4.1 mm by stress radiography and 4.4+/-2.3 mm by dynamic ultrasound. The 95% limits of agreement showed good agreement between the two methods. The paired difference between the two measurement methods varied with the magnitude of the measurement (P<0.001). Intra-observer repeatability of dynamic ultrasound was determined by the use of intra-class correlation coefficients and was 0.94 and 0.89 for the two investigators. Inter-observer repeatability was 0.85. The standard error of the measurement was 0.60 mm and 0.66 mm, for repeated measurements by the two investigators, and 0.85 mm between investigators. Repeatability coefficients demonstrated excellent consistency of measurement between sessions and good consistency between observers. CONCLUSION Dynamic ultrasound is a valid and reproducible method for the assessment and quantification of inferior glenohumeral laxity.
Collapse
Affiliation(s)
- S C Cheng
- Department of Orthopaedic & Accident Surgery, Queen's Medical Centre Campus, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | | | | | | | | |
Collapse
|
11
|
Staniforth ME, Cheng SC, Coyne DW. Once-weekly intravenous paricalcitol in the treatment of secondary hyperparathyroidism in hemodialysis patients. Clin Nephrol 2005; 63:454-60. [PMID: 15960147 DOI: 10.5414/cnp63454] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [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: 11/18/2022] Open
Abstract
BACKGROUND Paricalcitol, a vitamin D analog, is commonly administered three times weekly to control secondary hyperparathyroidism in hemodialysis patients. Less frequent dosing would be more convenient, require less nursing time, and be an option in other dialysis modalities. No studies have examined the efficacy of once-weekly dosing of paricalcitol. METHODS Chronic hemodialysis patients receiving a stable dose of paricalcitol three times weekly with intact PTH (iPTH) 100-500 ng/l were monitored during a two-week baseline, then were converted to a single mid-week paricalcitol dose equal to the previous cumulative weekly dose. Serum calcium and phosphorus were monitored weekly and iPTH levels determined during study Weeks 4 and 8. A single paricalcitol dose adjustment was made during study Week 5 based on iPTH to achieve a target value of 150-300 ng/l. Phosphate binders and calcium dialysate bath were kept constant during the study. RESULTS In the 25 patients, mean iPTH was 295 +/- 107 ng/l at baseline, and not significantly different at Week 4 (307 +/- 111 ng/l) or Week 8 (285 +/- 98 ng/l). Paricalcitol dose increases mid-study were almost exclusively in patients with iPTH > 300 ng/l. Calcium, phosphorus, and calcium x phosphorus product were not significantly different on weekly therapy. (Only one patient developed a calcium > 2.55 mmol/l during the study.) CONCLUSION Once-weekly dosing of paricalcitol is an effective option in treatment of secondary hyperparathyroidism. Less frequent dosing may better allocate nursing time and potentially benefit other patient populations with CKD and ESRD.
Collapse
Affiliation(s)
- M E Staniforth
- Department of Internal Medicine, Renal Division, Washington University School of Medicine, St. Louis, MO 63110, USA
| | | | | |
Collapse
|
12
|
Cheng SC, Hung TSL, Tse PYT. Investigation of the use of drained blood reinfusion after total knee arthroplasty: a prospective randomised controlled study. J Orthop Surg (Hong Kong) 2005; 13:120-4. [PMID: 16131672 DOI: 10.1177/230949900501300203] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
PURPOSE To compare the use of a blood salvage and reinfusion system with standard allogeneic blood transfusion after total knee arthroplasty--a procedure associated with significant postoperative blood loss. METHODS Between June 2002 and May 2004, 60 patients undergoing total knee arthroplasty were randomly allocated into a reinfusion group (n = 26) or a control group (n = 34). Patients in the reinfusion group had their blood reinfused from drains within 6 hours of surgery. Both groups received allogeneic blood transfusions according to specified transfusion criteria if the haemoglobin level fell below 90 g/l, or in the presence of severe anaemic symptoms. Haemoglobin levels and drain output were recorded daily for 3 consecutive days after surgery. RESULTS There was no significant difference between the 2 groups in demographic data, drain output, total blood loss, and mean postoperative haemoglobin levels. Significantly more allogeneic blood was required by the control group than by the reinfusion group (p = 0.022). CONCLUSION Postoperative reinfusion of drained blood reduced the need for blood transfusion after total knee arthroplasty, while having an effect on postoperative haemoglobin level equivalent to standard allogeneic blood transfusion.
Collapse
Affiliation(s)
- S C Cheng
- Department of Orthopaedics and Traumatology, Kwong Wah Hospital, Hong Kong.
| | | | | |
Collapse
|
13
|
Abstract
A mean residual life function is the average remaining life of a surviving subject, as it varies with time. The proportional mean residual life model was proposed by Oakes and Dasu (1990, Biometrika77, 409-410) in regression analysis to study its association with related covariates in absence of censoring. In this article, we develop some semiparametric estimation procedures to take censoring into account. The proposed methodology is evaluated via simulation studies, and further applied to a clinical trial of chemotherapy in postoperative radiotherapy of lung cancer patients.
Collapse
Affiliation(s)
- Y Q Chen
- Program in Biostatistics, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.
| | | | | | | |
Collapse
|
14
|
Maris JM, Yanik G, Messina J, Kersun L, Goldsby RE, Huberty J, Veatch J, Brophy P, Cheng SC, Hawkins RE, Matthay KK. A phase II study of 131I-MIBG for refractory neuroblastoma. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.8504] [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: 11/20/2022] Open
Affiliation(s)
- J. M. Maris
- Children’s Hosp of Philadelphia, Philadelphia, PA; Univ of Michigan, Ann Arbor, MI; Univ of CA, San Francisco, San Francisco, CA
| | - G. Yanik
- Children’s Hosp of Philadelphia, Philadelphia, PA; Univ of Michigan, Ann Arbor, MI; Univ of CA, San Francisco, San Francisco, CA
| | - J. Messina
- Children’s Hosp of Philadelphia, Philadelphia, PA; Univ of Michigan, Ann Arbor, MI; Univ of CA, San Francisco, San Francisco, CA
| | - L. Kersun
- Children’s Hosp of Philadelphia, Philadelphia, PA; Univ of Michigan, Ann Arbor, MI; Univ of CA, San Francisco, San Francisco, CA
| | - R. E. Goldsby
- Children’s Hosp of Philadelphia, Philadelphia, PA; Univ of Michigan, Ann Arbor, MI; Univ of CA, San Francisco, San Francisco, CA
| | - J. Huberty
- Children’s Hosp of Philadelphia, Philadelphia, PA; Univ of Michigan, Ann Arbor, MI; Univ of CA, San Francisco, San Francisco, CA
| | - J. Veatch
- Children’s Hosp of Philadelphia, Philadelphia, PA; Univ of Michigan, Ann Arbor, MI; Univ of CA, San Francisco, San Francisco, CA
| | - P. Brophy
- Children’s Hosp of Philadelphia, Philadelphia, PA; Univ of Michigan, Ann Arbor, MI; Univ of CA, San Francisco, San Francisco, CA
| | - S. C. Cheng
- Children’s Hosp of Philadelphia, Philadelphia, PA; Univ of Michigan, Ann Arbor, MI; Univ of CA, San Francisco, San Francisco, CA
| | - R. E. Hawkins
- Children’s Hosp of Philadelphia, Philadelphia, PA; Univ of Michigan, Ann Arbor, MI; Univ of CA, San Francisco, San Francisco, CA
| | - K. K. Matthay
- Children’s Hosp of Philadelphia, Philadelphia, PA; Univ of Michigan, Ann Arbor, MI; Univ of CA, San Francisco, San Francisco, CA
| |
Collapse
|
15
|
Lin SH, Lo CW, Cheng SC, Kuo MY, Chin LS. Use of reconstruction nails to manage ipsilateral displaced femoral neck-shaft fractures: assessment of a new approach. J Orthop Surg (Hong Kong) 2002; 10:185-93. [PMID: 12493933 DOI: 10.1177/230949900201000214] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [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] [Indexed: 11/16/2022] Open
Abstract
PURPOSE Owing to unpredictable femoral neck reduction, reconstruction nails are not suitable for fixation of group 3 ipsilateral femoral neck-shaft fractures. We developed a new one-step fixation technique to overcome this problem. This study aims to assess this new technique at the Orthopaedic Department, Chi-Mei Foundation Medical Center, Tainan. METHODS Of 31 consecutive patients with femoral fractures treated by reconstruction nails, five patients had group 3 ipsilateral femoral neck-shaft fractures, 4 of whom were treated by a new surgical technique. Two 5.0-mm drills were firstly inserted to tether the trochanter fragment, and distal locking screws were secondly applied to immobilise the shaft fracture. The neck-shaft angle was then restored in a closed fashion and proximal cephalomedullary screws were attached. Patients were followed up by post-operative radiography. RESULTS All 5 cases of group 3 ipsilateral femoral neck-shaft fracture obtained radiographic union without significant surgical sequelae. Three of the patients had implants removed. No patients presented with osteonecrosis at the 3-year follow-up. CONCLUSION The new approach to manage ipsilateral femoral neck-shaft fractures by using reconstruction nails obtains relatively good clinical results.
Collapse
Affiliation(s)
- S H Lin
- Orthopaedic Department, Chi-Mei Foundation Medical Center, 901 Junghua Road, Yungkang City, Tainan, Taiwan.
| | | | | | | | | |
Collapse
|
16
|
|
17
|
Lee-Chen GJ, Lin SP, Ko MH, Chuang CK, Chen CP, Lee HH, Cheng SC, Shen CH, Tseng KL, Li CL. Identification and characterization of mutations underlying Sanfilippo syndrome type A (mucopolysaccharidosis type IIIA). Clin Genet 2002; 61:192-7. [PMID: 12000360 DOI: 10.1034/j.1399-0004.2002.610304.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [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: 11/23/2022]
Abstract
Sanfilippo syndrome type A (mucopolysaccharidosis type IIIA; MPS IIIA) is caused by a deficiency of the lysosomal enzyme haparan N-sulphatase (NS). The genomic DNA segments of the NS gene from two Chinese patients with MPS IIIA were amplified by polymerase chain reaction, followed by DNA sequencing to study the molecular lesions. Four mutations (i.e. N42K, D235N, P293S and R377C) and five polymorphisms (i.e. IVS2-72A --> G, IVS2-26T --> C, IVS5+17C --> T, IVS5-37GC --> CTGT and R456H) were identified. Transfection of COS-7 cells with cDNA mutagenized to the corresponding mutations did not yield active enzyme, demonstrating the deleterious nature of the mutations. Western blot analysis revealed a 62-kDa precursor and 56-kDa mature forms for cells transfected with wild-type and polymorphic R456H enzymes. For cells transfected with mutant enzymes, the reduction in precursor and mature forms suggests an increased degradation of the mutant enzymes. The polymorphic DNA haplotype of the NS gene was analysed in 52 unrelated subjects. All five polymorphisms were in Hardy-Weinberg equilibrium. The strong non-random association among the five polymorphisms suggests little or no recombination in the NS gene.
Collapse
Affiliation(s)
- G J Lee-Chen
- Department of Biology, National Taiwan Normal University, Taipei, Taiwan, ROC.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Helgason CM, Malik DS, Cheng SC, Jobe TH, Mordeson JN. Statistical versus fuzzy measures of variable interaction in patients with stroke. Neuroepidemiology 2001; 20:77-84. [PMID: 11359073 DOI: 10.1159/000054764] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [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: 11/19/2022] Open
Abstract
UNLABELLED Evidence-based medicine, founded in probability-based statistics, applies what is the case for the collective to the individual patient. An intuitive approach, however, would define structure in the (physiologic) system of interest, the human being, directly relevant to other systems (patients) composed of similar variables. A difference in measure of variable interaction in the patient from that in the collective would show how extrapolation of information from the latter to the single patient is counterintuitive. METHODS We compare statistical to 'fuzzy' measures of variable interaction. Three diagnostic variables are considered in 30 stroke patients who underwent the same diagnostic tests. 'Fit' (fuzzy information) values [0, 1] for degree of variable severity were expertly assigned by 2 blinded raters for real and fabricated patients. Fabricated patients were composed of real-patient 'fit' values after shuffling. Real and fabricated patients were each numerically represented as a set. Three groups of fabricated patients and the real patient group were studied. Statistical [Pearson's product-moment (regression analysis) and Spearman's rank correlation] and three different fuzzy measures of variable interaction were applied to patient data. RESULTS Interaction for blood-vessel measured strong in real patients, and weak after one shuffle, using all fuzzy measures. By comparison, the same interaction was found in real patients by only 1 rater (Rater 2) using 1 statistical technique (Spearman's rank correlation) which, as did Pearson product-moment correlation, found a 'significant' interaction between blood-heart in fabricated patients. CONCLUSION Our study suggests that the measure of variable interaction in nature - as combined in the individual (real) patient - is captured robustly by fuzzy measures and not so by standard statistical measures.
Collapse
Affiliation(s)
- C M Helgason
- Department of Neurology and Psychiatry, University of Illinois College of Medicine at Chicago, Ill., 60611, USA.
| | | | | | | | | |
Collapse
|
19
|
Chan KT, Cheng SC, Xie H, Xie Y. A humanized monoclonal antibody constructed from intronless expression vectors targets human hepatocellular carcinoma cells. Biochem Biophys Res Commun 2001; 284:157-67. [PMID: 11374885 DOI: 10.1006/bbrc.2001.4837] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 12/11/2022]
Abstract
An anti-human hepatocellular carcinoma (HCC) monoclonal antibody, hHP-1, was genetically humanized from a murine monoclonal antibody. In this study, a concept of positional template approach was applied to design the amino acid sequence of hHP-1's variable region, and synthetic DNA fragments for protein expression were produced through overlapping PCR from single strand oligonucleotides. Synthetic DNA fragments and human antibody constant region cDNA were used to construct two CMV promotor-based expression vectors for the antibody light and heavy chains, in which the variable region was connected directly to the constant region without an intron sequence. Completely assembled humanized antibody was successfully expressed in mammalian cells as IgG1 kappa molecules and purified using protein A affinity column. The immunogenicity of the hHP1 was estimated by the amino acid sequence and determined through a HAMA (human anti-murine antibody) serum reaction assay. Results indicated that the immunogenicity of hHP-1 was significantly reduced. In vitro binding activity assay showed that the hHP-1 had retained its binding function to a human HCC SMMC-7721 cell-line, without cross binding to other human normal tissues. Immunofluorescence staining showed that hHP-1 had a strong binding activity to SMMC cells. A competitive binding assay showed that the relative binding activity of hHP-1 was approximately 25% binding activity of the original murine antibody. Our results indicate that a humanized antibody could be produced using intronless vectors and expressed as a complete IgG1 kappa antibody. Hence we believe that hHP-1 could be a potential candidate for HCC treatment.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal/isolation & purification
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal/physiology
- Antibody Specificity/immunology
- Base Sequence
- Binding, Competitive/drug effects
- Binding, Competitive/immunology
- CHO Cells
- Carcinoma, Hepatocellular/immunology
- Carcinoma, Hepatocellular/metabolism
- Chromatography, Affinity
- Cricetinae
- Cytomegalovirus/genetics
- Dose-Response Relationship, Drug
- Enzyme-Linked Immunosorbent Assay
- Fluorescent Antibody Technique
- Genetic Vectors/genetics
- Genetic Vectors/metabolism
- Humans
- Immunoglobulin G/isolation & purification
- Immunoglobulin G/pharmacology
- Immunoglobulin G/physiology
- Immunoglobulin Heavy Chains/genetics
- Immunoglobulin kappa-Chains/genetics
- Introns/genetics
- Liver Neoplasms/immunology
- Liver Neoplasms/metabolism
- Mice
- Molecular Sequence Data
- Serologic Tests
- Tumor Cells, Cultured
Collapse
Affiliation(s)
- K T Chan
- Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China
| | | | | | | |
Collapse
|
20
|
Abstract
Bcl-2 family proteins play a critical role in the regulation of apoptosis. Treatment of a human hepatocellular carcinoma cell line, QGY-7703, with Taxol induced apoptosis and Bcl-2 protein phosphorylation. Microscopic observation indicated that apoptotic bodies (0-15%) of Taxol-treated QGY cells appeared after 12 h of treatment, and apoptotic QGY cells gradually increased to 40% after 24 h and 70% after 48 h. A DNA fragmentation assay showed that Taxol induced genomic DNA cleavage into 200 bp DNA fragments. Bcl-2 protein was phosphorylated in Taxol-treated QGY cells within 3 h of treatment, and continued gradually up to 24 h. By 48 h, the protein was unphosphorylated. Other Bcl-2 family proteins, including Bax (a heterodimerization partner of Bcl-2), Bcl-XL, Bak and Bad, were expressed, but at constant levels. The results show a close correlation between Bcl-2 phosphorylation and apoptosis in QGY cells. The inactivation of Bcl-2 protein phosphorylation could be one of the key mechanisms needed for the induction of apoptosis in Taxol-treated QGY cells.
Collapse
Affiliation(s)
- S C Cheng
- Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR China
| | | | | |
Collapse
|
21
|
Chan EW, Cheng SC, Sin FW, Xie Y. Triptolide induced cytotoxic effects on human promyelocytic leukemia, T cell lymphoma and human hepatocellular carcinoma cell lines. Toxicol Lett 2001; 122:81-7. [PMID: 11397559 DOI: 10.1016/s0378-4274(01)00353-8] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [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: 01/23/2023]
Abstract
Triptolide, a traditional Chinese medicine, has been reported to be effective in the treatment of auto-immune diseases, and it can also induce anti-neoplastic activity on several human tumor cell lines. This study investigates the cytotoxic function and the functional mechanism of triptolide on tumor cells. Promyelocytic leukemia, (HL-60), T cell lymphoma (Jurkat), and human hepatocelluar carcinoma (SMMC-7721) cells were subjected to triptolide treatment, and cell growth inhibition was examined by XTT cell viability assay. Cell death mechanism (apoptosis) was confirmed through DNA fragmentation and DAPI staining. Triptolide inhibited 50% of cell growth (IC(50)) on HL-60 cells at 7.5 nM, Jurkat cells at 27.5 nM and SMMC cells at 32 nM. Characteristic apoptotic features including internucleosomal DNA fragmentation and chromatin condensation were observed in triptolide treated cells. Data from the study indicates that triptolide could induce apoptosis in human tumor cell lines and it may be applicable as a potential chemotherapeutic agent for cancer treatment.
Collapse
Affiliation(s)
- E W Chan
- Department of Biology, The Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong ROC
| | | | | | | |
Collapse
|
22
|
Cheng SC, Chu TS, Huang KY, Chen YM, Chang WK, Tsai TJ, Wu KD. Association of hypertriglyceridemia and insulin resistance in uremic patients undergoing CAPD. Perit Dial Int 2001; 21:282-9. [PMID: 11475344] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
OBJECTIVE Hyperlipidemia is frequently encountered in uremic patients and may be worsened by continuous ambulatory peritoneal dialysis (CAPD) treatment. The lipid abnormalities in these patients may be multifactorial. Insulin resistance (or its compensatory hyperinsulinemia) is commonly observed in uremic patients, but its association with hyperlipidemia in these patients has not been studied. PATIENTS AND METHODS Lipid profiles of 35 nondiabetic nonobese patients undergoing CAPD for more than 1 year (mean 52.3 months) were studied. Current laboratory data and parameters related to peritoneal dialysis (PD) within the previous 3 months were recorded. After overnight fasting and interruption of PD, an oral 75-g glucose tolerance test (OGTT) was examined. RESULTS After CAPD treatment for more than 12 months, these patients had higher serum triglyceride (TG) (p = 0.001) and total cholesterol (p = 0.0058) levels than their values before commencing CAPD. Twelve of 14 patients with serum TG higher than 200 mg/dL (high-TG) were diagnosed de novo, in contrast with only 1 patient diagnosed of de novo hypercholesterolemia (total cholesterol > 240 mg/dL). There was no difference in age, gender, body mass index (BMI), duration of PD treatment, serum albumin, hematocrit, intact serum parathyroid hormone (iPTH), peritoneal glucose load, solute transport, or weekly Kt/V urea between normal-TG and high-TG patients. After adjusting for age, gender, BMI, weekly Kt/V urea, and iPTH, the high-TG patients had higher levels of area under the curve for glucose (AUC(Glu)), area under the curve for insulin (AUC(Ins)), and AUC(Ins)/AUC(Glu) ratios (F = 10.63, 10.14, and 8.65; p = 0.0029, 0.0035, and 0.0065, respectively), indicating that the high-TG patients were more insulin resistant. There were 24 patients with normal glucose tolerance (NGT), and 11 patients with impaired glucose tolerance (IGT). The IGT group had higher serum TG (F = 10.43, p = 0.003) and total cholesterol (F = 8.05, p = 0.009) than the NGT group, after adjusting for BMI, duration of CAPD treatment, peritoneal glucose load, solute transport, serum albumin, and lipid levels before PD treatment. TheTG levels after CAPD treatment were positively correlated with AUC(Glu), AUC(Ins), and AUC(Ins)/AUC(Glu) ratio (r = 0.48, 0.53, and 0.49; p = 0.0037, 0.001, and 0.0028, respectively). CONCLUSIONS These results indicate that insulin resistance is an important factor in the development of hypertriglyceridemia in CAPD patients.
Collapse
Affiliation(s)
- S C Cheng
- Department of Internal Medicine, National Taiwan University Hospital, Taipei
| | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
In clinical trials designed to evaluate treatment efficacy, it is common practice to terminate a treatment arm in which the observed rate of an adverse event is unacceptably high. This practice may be formalized by a group-sequential test based on a multivariate outcome including both adverse and efficacy events. Recently, Thall and Cheng proposed a family of tests for randomized trials of an experimental treatment versus a standard where patient outcome is bivariate with entries characterizing efficacy and safety. The test is motivated by the idea that clinically meaningful improvements over the standard may be characterized by a two-dimensional parameter quantifying trade-offs between efficacy and safety. We provide optimal two-stage designs based on this test that minimize either the mean sample size under the null hypothesis of no treatment difference, or the maximum sample size if the trial continues to a second stage. A more general group-sequential version of the design also is described, an illustration is provided, and application to the special case of single-arm phase II trials is discussed.
Collapse
Affiliation(s)
- P F Thall
- Department of Biostatistics, Box 447, The University of Texas, M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030, USA.
| | | |
Collapse
|
24
|
Zhou J, Cheng SC, Luo D, Xie Y. Study of multi-drug resistant mechanisms in a taxol-resistant hepatocellular carcinoma QGY-TR 50 cell line. Biochem Biophys Res Commun 2001; 280:1237-42. [PMID: 11162660 DOI: 10.1006/bbrc.2001.4268] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [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: 11/22/2022]
Abstract
Cancer chemotherapy with taxol often fails due to acquired resistance of cancer cells, which is frequently associated with an overexpression of P-gp and alterations of beta-tubulin. A taxol-resistant cell line, QGY-TR50, derived from a human hepatocellular carcinoma (HCC) QGY-7703 cell line was used to investigate the mechanisms of taxol-resistance. QGY-TR50 cells showed more than 250-fold resistance to taxol and exhibited cross-resistance to other drugs including actinomycin D, doxorubicin, vinblastine, and vincristine. P-gp was highly expressed in QGY-TR50 cells. Expression levels of five human beta-tubulin isotypes (betaI-, betaII-,betaIII-, betaIva, and betaIvb-tubulin) were examined by real-time semi-quantitative PCR. Comparing with QGY-7703 cells, QGY-TR50 cells did not show any significant change in the expression levels of betaI-, betaIva, and betaIvb-tubulin. While a 1.2-fold increased in betaII-tubulin and a 0.5-fold decreased in betaIII-tubulin levels were observed. All results suggest that the P-glycoprotein could be one key factor involved in enhancing drug resistance in QGY-TR50 cells.
Collapse
MESH Headings
- ATP Binding Cassette Transporter, Subfamily B/genetics
- ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics
- Antineoplastic Agents/pharmacology
- Carcinoma, Hepatocellular/drug therapy
- Carcinoma, Hepatocellular/genetics
- Carcinoma, Hepatocellular/pathology
- Cell Survival/drug effects
- Dactinomycin/pharmacology
- Doxorubicin/pharmacology
- Drug Resistance, Multiple/genetics
- Drug Resistance, Neoplasm
- Fluorouracil/pharmacology
- Gene Expression Regulation, Neoplastic
- Humans
- Inhibitory Concentration 50
- Mitomycin/pharmacology
- Paclitaxel/pharmacology
- Protein Isoforms/genetics
- RNA, Neoplasm/genetics
- RNA, Neoplasm/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Time Factors
- Tubulin/genetics
- Tumor Cells, Cultured
- Vinblastine/pharmacology
- Vincristine/pharmacology
Collapse
Affiliation(s)
- J Zhou
- Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong SAR, China
| | | | | | | |
Collapse
|
25
|
Chen CH, Tsai WY, Chen HR, Wang CH, Cheng SC. Identification and characterization of two novel components of the Prp19p-associated complex, Ntc30p and Ntc20p. J Biol Chem 2001; 276:488-94. [PMID: 11018040 DOI: 10.1074/jbc.m006958200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [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: 11/06/2022] Open
Abstract
The yeast Saccharomyces cerevisiae Prp19p protein is an essential splicing factor and a spliceosomal component. It is not tightly associated with small nuclear RNAs (snRNAs) but is associated with a protein complex consisting of at least eight proteins. We have identified two novel components of the Prp19p-associated complex, Ntc30p and Ntc20p. Like other identified components of the complex, both Ntc30p and Ntc20p are associated with the spliceosome in the same manner as Prp19p immediately after or concurrently with dissociation of U4, indicating that the entire complex may bind to the spliceosome as an intact form. Neither Ntc30p nor Ntc20p directly interacts with Prp19p, but both interact with another component of the complex, Ntc85p. Immunoprecipitation analysis revealed an ordered interactions of these components in formation of the Prp19p-associated complex. Although null mutants of NTC30 or NTC20 showed no obvious growth phenotype, deletion of both genes impaired yeast growth resulting in accumulation of precursor mRNA. Extracts prepared from such a strain were defective in pre-mRNA splicing in vitro, but the splicing activity could be restored upon addition of the purified Prp19p-associated complex. These results indicate that Ntc30p and Ntc20p are auxiliary splicing factors the functions of which may be modulating the function of the Prp19p-associated complex.
Collapse
Affiliation(s)
- C H Chen
- Institute of Microbiology and Immunology, National Yang-Ming University, Shih-Pai 112, Taiwan, Republic of China
| | | | | | | | | |
Collapse
|
26
|
Wong HT, Cheng SC, Chan EW, Sheng ZT, Yan WY, Zheng ZX, Xie Y. Plasmids encoding foot-and-mouth disease virus VP1 epitopes elicited immune responses in mice and swine and protected swine against viral infection. Virology 2000; 278:27-35. [PMID: 11112477 DOI: 10.1006/viro.2000.0607] [Citation(s) in RCA: 64] [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] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
VP1 is a capsid protein of foot-and-mouth disease virus (FMDV) and contains epitopes of the virus. Plasmids encoding two VP1 epitopes (amino acid residues 141-160 and 200-213) and a host-self immunoglobulin molecule were constructed to produce a new type of FMD DNA vaccine. Two plasmids, namely, pCEIM and pCEIS, containing mouse immunoglobulin (IgG) or swine IgG were subjected to immunogenicity testing in mice and swine, respectively. In mice administrated pCEIM in the abdomen using a genegun, both FMDV-specific T-cell proliferation and neutralizing antibodies were detected. In swine immunized with pCEIS at the back of the ear, immune responses were achieved after the second administration. Swine showed a T-cell proliferative response with a stimulation index (SI) of up to 8.1 and a neutralizing antibody response that was able to protect suckling mice from 10(2) LD(50) (lethal dose 50) FMDV challenge. To compare the immunogenicity of the DNA-based vaccine candidate, versus the protein-based vaccine candidates, a second group of swine was immunized with the protein F1-scIgG, which was encoded by the plasmid pCEIS. Injection with F1-scIgG elicited a T-cell proliferative response of SI < 1.7 and a neutralizing antibody response that protected suckling mice from up to 10(5) LD(50) FMDV challenge. In the challenge test, three of three swine immunized with pCEIS were fully protected from FMDV challenge.
Collapse
Affiliation(s)
- H T Wong
- Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, China
| | | | | | | | | | | | | |
Collapse
|
27
|
Luo D, Cheng SC, Xie H, Xie Y. Effects of Bcl-2 and Bcl-XL protein levels on chemoresistance of hepatoblastoma HepG2 cell line. Biochem Cell Biol 2000; 78:119-26. [PMID: 10874473] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
The ratio between apoptotic promoters and repressors in the Bcl-2 family determines the chemosensitivity of cells to apoptotic stimuli. This study examines the chemoresistance of a transfected human hepatoblastoma HepG2 cell-line during Taxol and Doxorubicin application. Sense bcl-2, and anti-sense bcl-XL gene fragments were separately inserted into HepG2 cells via stable transfection. The expression profile of the Bcl-2 family proteins was determined by Western blot analysis. Chemosensitivity of the transfected cells was measured by Trypan blue exclusion assay and XTT reduction assay during drug application. In the absence of Bax protein, HepG2 cells with elevated Bcl-2 protein levels did not exhibit any significant increase in chemosensitivity towards the drugs. Transfected cells with reduced Bcl-XL levels became more sensitive to the drugs, and a significant difference in IC50 values was observed. The chemosensitivity of HepG2 cells to Taxol and Doxorubicin was not affected by Bcl-2 levels, while reduction of Bcl-XL levels rendered the cells more sensitive to the drugs. This suggests that the Bcl-2 protein alone could not protect HepG2 cells from drug-induced apoptosis, and that the Bcl-XL protein may be a target for gene therapy in hepatoblastoma treatment.
Collapse
Affiliation(s)
- D Luo
- Department of Biology, Hong Kong University of Science and Technology, Kowloon, China
| | | | | | | |
Collapse
|
28
|
Chan EW, Wong HT, Cheng SC, Yan WY, Zheng ZX, Sheng ZT, Zhu LQ, Xie Y. An immunoglobulin G based chimeric protein induced foot-and-mouth disease specific immune response in swine. Vaccine 2000; 19:538-46. [PMID: 11027819 DOI: 10.1016/s0264-410x(00)00186-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [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: 11/16/2022]
Abstract
Epitopes containing the residues 141aa-160aa and 200aa-213aa from foot-and-mouth disease (FMD) serotype O1K HK type FMDV VP1 were joined to a swine immunoglobulin G single heavy chain constant region (scIgG), creating a novel chimeric protein, named F1-scIgG. In this study, inoculation with F1-scIgG induced both FMD virus-neutralizing antibody response and T cell response in swine. Antisera from these F1-scIgG-inoculated swine protected suckling mice against 1000 lethal dose 50 (1000LD(50)) FMD challenge. F1-scIgG-inoculated swine were also fully protected against 50LD(50) FMD virus challenge. The present study demonstrates the clear potential for viral epitopes linked with self-Ig in novel FMD vaccine design.
Collapse
Affiliation(s)
- E W Chan
- Department of Biology, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Abstract
In Saccharomyces cerevisiae, positioning of the mitotic spindle depends on the interaction of cytoplasmic microtubules with the cell cortex. In this process, cortical Kar9p in the bud acts as a link between the actin and microtubule cytoskeletons. To identify Kar9p-interacting proteins, a two-hybrid screen was conducted with the use of full-length Kar9p as bait, and three genes were identified: BIM1, STU2, and KAR9 itself. STU2 encodes a component of the spindle pole body. Bim1p is the yeast homologue of the human microtubule-binding protein EB1, which is a binding partner to the adenomatous polyposis coli protein involved in colon cancer. Eighty-nine amino acids within the third quarter of Bim1p was sufficient to confer interaction with Kar9p. The two-hybrid interactions were confirmed with the use of coimmunoprecipitation experiments. Genetic analysis placed Bim1p in the Kar9p pathway for nuclear migration. Bim1p was not required for Kar9p's cortical or spindle pole body localization. However, deletion of BIM1 eliminated Kar9p localization along cytoplasmic microtubules. Furthermore, in the bim1 mutants, the cytoplasmic microtubules no longer intersected the cortical dot of Green Fluorescent Protein-Kar9p. These experiments demonstrate that the interaction of cytoplasmic microtubules with the Kar9p cortical attachment site requires the microtubule-binding protein Bim1p.
Collapse
Affiliation(s)
- R K Miller
- Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, New Jersey 08544, USA
| | | | | |
Collapse
|
30
|
Huang RN, Yeh HY, Cheng SC, Chow LP, Lee TC. Arsanilic acid-Sepharose chromatography of pyruvate kinase from KB cells. J Chromatogr B Biomed Sci Appl 2000; 740:109-16. [PMID: 10798300 DOI: 10.1016/s0378-4347(00)00043-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In the present study, arsanical-based affinity chromatography for pyruvate kinase (PK) isolation was explored. p-Arsanilic acid (4-aminophenyl arsonic acid), which contains an arsonic acid moiety structurally similar to inorganic pentavalent arsenate, was conjugated to Sepharose 4B via its para-amino group to form an As(V)-Sepharose matrix. The cellular proteins from KB cells bound to arsonic acid moieties were eluted by 50 mM sodium arsenate in Tris-HCl buffer (50 mM, pH 7.6). A single protein band with a molecular mass of 58 kDa was shown on a sodium dodecyl sulfate-polyacrylamide gel. By immunoblotting, amino acid sequencing and enzymatic analysis, the sodium arsenate-eluted 58-kDa protein was demonstrated to be a human PK (type M2). By using this one-step As(V)-Sepharose chromatography, PK from KB cells was purified 35.4-fold with a specific activity of 153.15 U/mg protein in the presence of 6 mM fructose-1,6-biphosphate. Although PK was eluted from an As(V)-Sepharose column with sodium arsenate, PK activity was apparently inhibited by the used eluent system, but not by p-arsanilic acid, indicating a specific interaction of As(V) to PK. In summary, our results indicate that As(V)-Sepharose can serve as a simple and efficient chromatographic support for PK purification from KB cells.
Collapse
Affiliation(s)
- R N Huang
- Institute of Life Sciences, National Central University, Chung-Li, Taiwan, ROC.
| | | | | | | | | |
Collapse
|
31
|
Luo D, Cheng SC, Xie Y. Expression of Bcl-2 family proteins during chemotherapeutic agents-induced apoptosis in the hepatoblastoma HepG2 cell line. Br J Biomed Sci 2000; 56:114-22. [PMID: 10695052] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
This study demonstrates that two anticancer drugs, taxol and doxorubicin (Dox), can kill human hepatoblastoma HepG2 cells in a dose-dependent manner via the induction of apoptosis. Characteristic events, including externalization of phosphatidylserine, cytoplasmic shrinkage, chromatin condensation and DNA degradation, were observed in a large majority of the drug-treated cells. DNA fragmentation showed that a ladder of DNA fragments of approximately 200 bp multiples was observed in taxol-treated, but not in Dox-treated, cells. In addition, the expression patterns of Bcl-2 family members during taxol or Dox treatment were investigated. Results from Western blot analysis indicated that HepG2 cells did not express either the death repressor Bcl-2, or the death promoters Bcl-XS and Bax. However, during the apoptotic process one death repressor, Bcl-XL, and two death promoters, Bak and Bad, were expressed. The expression levels of Bcl-XL and Bak remained unchanged, whereas the level of Bad was down-regulated. As the ratio between death repressors and death promoters in the Bcl-2 family will determine the sensitivity of cells to apoptotic stimuli, the findings suggest that the changed expression patterns of Bcl-2 family proteins caused by anticancer drugs in liver cancer cells may be involved in chemoresistance.
Collapse
Affiliation(s)
- D Luo
- Department of Biology, Hong Kong University of Science and Technology, SAR, China
| | | | | |
Collapse
|
32
|
Khoo KL, Cheng SC, Tan YK. Endobronchial mass in a patient with Burkholderia pseudomallei infection. Ann Acad Med Singap 2000; 29:108-9. [PMID: 10748977] [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] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
INTRODUCTION Burkholderia pseudomallei infection, the great mimicker of infectious diseases, has protean clinical manifestations. CLINICAL PICTURE A 37-year-old man who presented with community-acquired pneumonia affecting the right upper lobe had unremitting fever. Bronchoscopy showed an endobronchial mass in the right upper lobe bronchus. TREATMENT Intravenous ceftriaxone and oral erythromycin, with empiric antituberculous treatment added later. This was subsequently switched to intravenous ceftazidime and oral doxycycline after the diagnosis was made. OUTCOME There was resolution of the endobronchial mass. CONCLUSION This case illustrates a unique and unreported presentation of melioidosis.
Collapse
Affiliation(s)
- K L Khoo
- Department of Respiratory & Critical Care Medicine, Singapore General Hospital, Singapore
| | | | | |
Collapse
|
33
|
Abstract
In the context of competing risks, the cumulative incidence function is often used to summarize the cause-specific failure-time data. As an alternative to the proportional hazards model, the additive risk model is used to investigate covariate effects by specifying that the subject-specific hazard function is the sum of a baseline hazard function and a regression function of covariates. Based on such a formulation, we present an approach to constructing simultaneous confidence intervals for the cause-specific cumulative incidence function of patients with given risk factors. A melanoma data set is used for the purpose of illustration.
Collapse
Affiliation(s)
- Y Shen
- Department of Biomathematics, M. D. Anderson Cancer Center, University of Texas, Houston 77030, USA.
| | | |
Collapse
|
34
|
Abstract
Bcl-2 protein is one of the major apoptosis regulators. The study examines the effect of Bcl-2 protein on the chemosensitivity of a human hepatocellular carcinoma cell line, QGY-7703. Western blot analysis showed that Bcl-2 and Bax proteins were expressed in QGY-7703 cells. Characteristic features of Taxol- and doxorubicin-induced apoptosis were evidenced by the Annexin-V binding assay, TUNEL and DAPI staining. At constant Bax protein levels, stable sense and antisense gene-transfected QGY-7703 cells showed that constitutive expression of Bcl-2 could render the cells more resistant to Taxol and doxorubicin. Contrarily, decreased Bcl-2 levels caused the cells to be more sensitive to the drugs. As Bcl-2 levels are directly proportional to the resistance of QGY-7703 cells to Taxol and doxorubicin, manipulation of Bcl-2 could be performed to enhance the sensitivity of liver cancer to chemotherapeutic agents.
Collapse
Affiliation(s)
- D Luo
- Department of Biology, Hong Kong University of Science and Technology, Hong Kong, China
| | | | | | | |
Collapse
|
35
|
Abstract
In addition to their desired anticancer effects, most cancer treatments may also cause transient toxicity, permanent organ damage, or death. A critical question in comparing an experimental treatment to a standard is how much increase in an adverse event rate is an acceptable trade-off for achieving a targeted improvement in efficacy, or vice versa. We consider settings where one may characterize patient outcome as a bivariate (efficacy, safety) variable and quantify treatment effect as a corresponding two-dimensional parameter. A set of target parameters, each representing a clinically meaningful improvement over the standard, are elicited from the physician. Each target is a two-dimensional generalization of the usual one-dimensional shift parameter. We define the alternative hypothesis in the two-dimensional effect space as the convex hull of the sets of parameters that are at least as desirable as each target point. The rejection region is obtained by shifting the alternative toward (0,0) to achieve a given type I error, with sample size computed to achieve a given power at the targets. The method is illustrated by application to two cancer chemotherapy trials.
Collapse
Affiliation(s)
- P F Thall
- Department of Biostatistics, M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
| | | |
Collapse
|
36
|
Fleming JB, Berman RS, Cheng SC, Chen NP, Hunt KK, Feig BW, Respondek PM, Yasko AW, Pollack A, Patel SR, Burgess MA, Papadopoulos NE, Plager C, Zagars G, Benjamin RS, Pollock RE, Pisters PW. Long-term outcome of patients with American Joint Committee on Cancer stage IIB extremity soft tissue sarcomas. J Clin Oncol 1999; 17:2772-80. [PMID: 10561352 DOI: 10.1200/jco.1999.17.9.2772] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [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: 02/03/2023] Open
Abstract
PURPOSE It has been suggested that patients with small (< 5 cm), high-grade extremity soft tissue sarcomas (STS) have an excellent overall prognosis and, consequently, may not require adjuvant therapies. PATIENTS AND METHODS A comprehensive review of all patients with extremity STS treated at a tertiary care cancer hospital over a 9-year period (January 1984 to December 1992) was performed. Prognostic factors, treatment data, and long-term outcome were evaluated in the subset of 111 patients with American Joint Committee on Cancer stage IIB (G3/4, T1a/b) disease. RESULTS The median tumor size was 3.0 cm (range, 0.6 to 4.9 cm), and 55 tumors (50%) were deep in location. All patients underwent surgical resection; 68 (61%) received pre- or postoperative radiotherapy, and 32 (29%) received doxorubicin-based chemotherapy. The median follow-up was 76 months. Forty patients (36%) experienced 59 recurrences. First recurrences occurred at local, regional, and distant sites in 21, five, and 14 patients, respectively. The 5-year actuarial local recurrence-free, distant recurrence-free, disease-free, and overall survival rates were 82%, 83%, 68%, and 83%, respectively. The presence of a microscopically positive surgical margin was an independent adverse prognostic factor for both local recurrence (relative risk [RR] = 3.75; 95% confidence interval [CI], 1.25 to 11.25; P =.02) and disease-free survival (RR = 2.57; 95% CI, 1.33 to 4.98; P =.005). CONCLUSION Event-free outcome for this subset of patients with high-grade STS does not seem as favorable as previously reported by other investigators. Patients who undergo maximal surgical resection with microscopically positive margins represent a subset of T1 STS patients who warrant consideration for adjuvant therapies.
Collapse
Affiliation(s)
- J B Fleming
- Sarcoma Center at The University of Texas M.D. Anderson Cancer Center, Houston, TX 77030-4195, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Chen HR, Tsao TY, Chen CH, Tsai WY, Her LS, Hsu MM, Cheng SC. Snt309p modulates interactions of Prp19p with its associated components to stabilize the Prp19p-associated complex essential for pre-mRNA splicing. Proc Natl Acad Sci U S A 1999; 96:5406-11. [PMID: 10318896 PMCID: PMC21872 DOI: 10.1073/pnas.96.10.5406] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [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: 11/18/2022] Open
Abstract
The SNT309 gene was identified via a mutation that causes lethality of cells in combination with a prp19 mutation. We showed previously that Snt309p is a component of the Prp19p-associated complex and that Snt309p, like Prp19p, is associated with the spliceosome immediately after or concomitantly with dissociation of U4 from the spliceosome. We show here that extracts prepared from the SNT309-deleted strain (DeltaSNT309) were defective in splicing but could be complemented by addition of the purified Prp19p-associated complex. Isolation of the Prp19p-associated complex from DeltaSNT309 extracts indicated that the complex was destabilized in the absence of Snt309p and dissociated on affinity chromatography, suggesting a role of Snt309p in stabilization of the Prp19p-associated complex. Addition of the affinity-purified Prp19p-Snt309p binary complex to DeltaSNT309 extracts could reconstitute the Prp19p-associated complex. Genetic analysis further suggests that Snt309p plays a role in modulating interactions of Prp19p with other associated components to facilitate formation of the Prp19p-associated complex. A model for how Snt309p modulates such interactions is proposed.
Collapse
Affiliation(s)
- H R Chen
- Institute of Microbiology and Immunology, National Yang-Ming University, Shih-Pai, Taiwan 112
| | | | | | | | | | | | | |
Collapse
|
38
|
Tsai WY, Chow YT, Chen HR, Huang KT, Hong RI, Jan SP, Kuo NY, Tsao TY, Chen CH, Cheng SC. Cef1p is a component of the Prp19p-associated complex and essential for pre-mRNA splicing. J Biol Chem 1999; 274:9455-62. [PMID: 10092627 DOI: 10.1074/jbc.274.14.9455] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [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: 11/06/2022] Open
Abstract
The Prp19p protein of the budding yeast Saccharomyces cerevisiae is an essential splicing factor and is associated with the spliceosome during the splicing reaction. We have previously shown that Prp19p is not tightly associated with small nuclear ribonucleoprotein particles but is associated with a protein complex consisting of at least eight protein components. By sequencing components of the affinity-purified complex, we have identified Cef1p as a component of the Prp19p-associated complex, Ntc85p. Cef1p could directly interact with Prp19p and was required for pre-mRNA splicing both in vivo and in vitro. The c-Myb DNA binding motif at the amino terminus of Cef1p was required for cellular growth but not for interaction of Cef1p with Prp19p or Cef1p self-interaction. We have identified a small region of 30 amino acid residues near the carboxyl terminus required for both cell viability and protein-protein interactions. Cef1p was associated with the spliceosome in the same manner as Prp19p, i.e. concomitant with or immediately after dissociation of U4. The anti-Cef1p antibody inhibited binding to the spliceosome of Cef1p, Prp19p, and at least three other components of the Prp19p-associated complex, suggesting that the Prp19p-associated complex is likely associated with the spliceosome and functions as an integral complex.
Collapse
Affiliation(s)
- W Y Tsai
- Institute of Microbiology and Immunology, National Yang-Ming University Shih-Pai, Taiwan, Republic of China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Wu WH, Bandilla E, Ciccone DS, Yang J, Cheng SC, Carner N, Wu Y, Shen R. Effects of qigong on late-stage complex regional pain syndrome. Altern Ther Health Med 1999; 5:45-54. [PMID: 9893315] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
CONTEXT Despite the growing popularity of qigong in the West, few well-controlled studies using a sham master to assess the clinical efficacy of qigong have been conducted. OBJECTIVE To study the effect of qigong on treatment-resistant patients with late-stage complex regional pain syndrome type I. DESIGN Block-random placebo-controlled clinical trial. SETTING Pain Management Center at New Jersey Medical School. PATIENTS 26 adult patients (aged 18 to 65 years) with complex regional pain syndrome type I. INTERVENTIONS The experimental group received qi emission and qigong instruction (including home exercise) by a qigong master. The control group received a similar set of instructions by a sham master. The experimental protocol included 6 forty-minute qigong sessions over 3 weeks, with reevaluation at 6 and 10 weeks. Assessment included comprehensive medical history, physical exam, psychological evaluation, necessary diagnostic testing. Symptom Check List 90, and the Carleton University Responsiveness to Suggestion Scale. MAIN OUTCOME MEASURES Thermography, swelling, discoloration, muscle wasting, range of motion, pain intensity rating, medication usage, behavior assessment (activity level and domestic disability), frequency of pain awakening, mood assessment, and anxiety assessment. RESULTS 22 subjects completed the protocol. Among the genuine qigong group, 82% reported less pain by the end of the first training session compared to 45% of control patients. By the last training session, 91% of qigong patients reported analgesia compared to 36% of control patients. Anxiety was reduced in both groups over time, but the reduction was significantly greater in the experimental group than in the control group. CONCLUSIONS Using a credible placebo to control for nonspecific treatment effects, qigong training was found to result in transient pain reduction and long-term anxiety reduction. The positive findings were not related to preexperimental differences between groups in hypnotizability. Future studies of qigong should control for possible confounding influences and perhaps use clinical disorders more responsive to psychological intervention.
Collapse
Affiliation(s)
- W H Wu
- Pain Management Center, Newark, NJ, USA
| | | | | | | | | | | | | | | |
Collapse
|
40
|
Abstract
A recent meta-analysis of 16 publications suggested that bone mineral density (BMD) is not associated with vitamin D receptor (VDR) gene polymorphism (VDRGP) at the 0.05 significance level when a study with genotyping mistakes is excluded. We wished to determine whether 'positive' findings supporting the BMD-VDRGP association may be explained by chance, and what factors affect the outcomes of these studies. Seventy-five articles and abstracts on the association of VDRGP with BMD and related skeletal phenotypes published before January 1997 were identified. Twenty-three of 67 (34.3%) studies on spinal BMD and 22 of 51 (43.1%) on femoral neck BMD had found a BMD-VDRGP association at p < 0.05, significantly (p = 7 x 10(-14) for spinal BMD, p = 9 x 10(-16) for hip BMD) higher than the expected 5% false positive rate under the null hypothesis of 'no association'. 'Positive' results were more frequently observed in studies on females before the menopause than those on females after the menopause (p < 0.02) or on male and female subjects combined (p < 0.05) when skeletal phenotypes at any bone sites were considered. The 'positive rate' among studies was also influenced by the age range of subjects studied and by the inclusion of subjects with osteoporosis. It is concluded that: (1) BMD is associated with VDRGP with high levels of confidence and (2) non-genetic factors and genetic heterogeneity interfere with the detection of the effects of VDRGP on bone phenotypes.
Collapse
Affiliation(s)
- G Gong
- Osteoporosis Research Center, Creighton University, Omaha, Nebraska 68131, USA
| | | | | | | | | | | | | |
Collapse
|
41
|
Abstract
Recent developments and advances in contrast echocardiography have been made to improve the diagnosis and evaluation of cardiac structures and function. By coupling new developments in acoustic instrumentation with new contrast agents, information that was previously difficult or impossible to gather by standard 2-dimensional echocardiography can now be obtained. Numerous studies have been published confirming the advantages of using contrast during echocardiographic studies, particularly with stress testing and myocardial perfusion. This review aims to summarize (1) the various contrast agents that are available or being developed; (2) factors that have been found to affect the strength of enhanced signals; (3) the new developments in instrumentation that improve the ability of scanners to differentiate echo contrast from cardiac tissue; and (4) the documented and possible future uses of contrast echocardiography.
Collapse
Affiliation(s)
- S C Cheng
- Department of Internal Medicine, Rush-Presbyterian-St. Luke's Medical Center and the University of Illinois at Chicago, 60612-3833, USA
| | | | | |
Collapse
|
42
|
Chen HR, Jan SP, Tsao TY, Sheu YJ, Banroques J, Cheng SC. Snt309p, a component of the Prp19p-associated complex that interacts with Prp19p and associates with the spliceosome simultaneously with or immediately after dissociation of U4 in the same manner as Prp19p. Mol Cell Biol 1998; 18:2196-204. [PMID: 9528791 PMCID: PMC121462 DOI: 10.1128/mcb.18.4.2196] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [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: 02/07/2023] Open
Abstract
The yeast protein Prp19p is essential for pre-mRNA splicing and is associated with the spliceosome concurrently with or just after dissociation of U4 small nuclear RNA. In splicing extracts, Prp19p is associated with several other proteins in a large protein complex of unknown function, but at least one of these proteins is also essential for splicing (W.-Y. Tarn, C.-H. Hsu, K.-T. Huang, H.-R. Chen, H.-Y. Kao, K.-R. Lee, and S.-C. Cheng, EMBO J. 13:2421-2431, 1994). To identify proteins in the Prp19p-associated complex, we have isolated trans-acting mutations that exacerbate the phenotypes of conditional alleles of prp19, using the ade2-ade3 sectoring system. A novel splicing factor, Snt309p, was identified through such a screen. Although the SNT309 gene was not essential for growth of Saccharomyces cerevisiae under normal conditions, yeast cells containing a null allele of the SNT309 gene were temperature sensitive and accumulated pre-mRNA at the nonpermissive temperature. Far-Western blot analysis revealed direct interaction between Prp19p and Snt309p. Snt309p was shown to be a component of the Prp19p-associated complex by Western blot analysis. Immunoprecipitation studies demonstrated that Snt309p was also a spliceosomal component and associated with the spliceosome in the same manner as Prp19p during spliceosome assembly. These results suggest that the functions of Prp19p and Snt309p in splicing may require coordinate action of these two proteins.
Collapse
Affiliation(s)
- H R Chen
- Institute of Microbiology and Immunology, National Yang-Ming University, Shih-Pai, Taiwan, Republic of China
| | | | | | | | | | | |
Collapse
|
43
|
|
44
|
Cheng SC, Fine JP, Wei LJ. Prediction of cumulative incidence function under the proportional hazards model. Biometrics 1998; 54:219-28. [PMID: 9544517] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In the presence of dependent competing risks in survival analysis, the Cox model can be utilized to examine the covariate effects on the cause-specific hazard function for the failure type of interest. For this situation, the cumulative incidence function provides an intuitively appealing summary curve for marginal probabilities of this particular event. In this paper, we show how to construct confidence intervals and bands for such a function under the Cox model for future patients with certain covariates. Our proposals are illustrated with data from a prostate cancer trial.
Collapse
Affiliation(s)
- S C Cheng
- Department of Biomathematics, M. D. Anderson Cancer Center, University of Texas, Houston 77030, USA.
| | | | | |
Collapse
|
45
|
Pisters PW, Patel SR, Varma DG, Cheng SC, Chen NP, Nguyen HT, Feig BW, Pollack A, Pollock RE, Benjamin RS. Preoperative chemotherapy for stage IIIB extremity soft tissue sarcoma: long-term results from a single institution. J Clin Oncol 1997; 15:3481-7. [PMID: 9396401 DOI: 10.1200/jco.1997.15.12.3481] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.4] [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: 02/05/2023] Open
Abstract
PURPOSE To review a single institution's long-term results with doxorubicin-based preoperative chemotherapy for American Joint Committee on Cancer (AJCC) stage IIIB extremity soft tissue sarcoma (STS). PATIENTS AND METHODS The records of all patients with AJCC stage IIIB extremity STS treated with preoperative chemotherapy between 1986 and 1990 at The University of Texas M.D. Anderson Cancer Center were reviewed to assess rates of response, local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), disease-free survival (DFS), and overall survival (OS). RESULTS Seventy-six patients with stage IIIB disease received preoperative chemotherapy. The median sarcoma size was 10 cm. Seventy-two patients (95%) had tumors located deep to the muscular fascia. Most patients received a median of three preoperative cycles of doxorubicin and dacarbazine (ADIC), cyclophosphamide and ADIC (CyADIC), or other doxorubicin-based regimens. Radiographic response rates were as follows: complete response (CR), 9%; partial response (PR), 19%; minor response, 13%; stable disease, 30%; and progression, 30%. The overall objective major response rate (CRs plus PRs) was 27%. At a median follow-up time of 85 months, 5-year actuarial rates of LRFS, DMFS, DFS, and OS with 95% confidence intervals (CIs) were 83% (CI, 73% to 94%), 52% (CI, 41% to 66%), 46% (CI, 35% to 60%), and 59% (CI, 48% to 72%), respectively. Comparison of responding patients (CRs plus PRs) and nonresponding patients did not show any significant differences in LRFS, DMFS, DFS, or OS. CONCLUSION Preoperative doxorubicin-based chemotherapy was associated with response, DFS, and OS rates similar to those observed in randomized postoperative chemotherapy trials. Responding patients had rates of LRFS, DMFS, DFS, and OS comparable to those of nonresponders.
Collapse
Affiliation(s)
- P W Pisters
- Sarcoma Center, The University of Texas M.D. Anderson Cancer Center, Houston 77030-4195, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
|
47
|
Abstract
p53 mutation has been rarely reported in cerebral primitive neuroectodermal tumors (PNET). To determine the significance of p53 mutations in the development of cerebral PNET, we studied cerebral PNET samples from 14 patients, 8 females and 6 males with a mean age of 38 years (range 10 months to 77 years) who had total or subtotal surgical resection. Histological typing of PNET with neuronal (N) and non-neuronal (NN) differentiation groups revealed 8 and 6 cases, respectively. Six (43%) of the 14 patients had p53 mutation. The p53(+) and p53(-) groups had an age range of 19-77 with a mean of 49 years and 10 months to 57 years with a mean of 30 years, respectively. p53 expression between the PNET-N and PNET-NN groups was 5 of 8 (62.5%) and 1 of 6 (16.7%), respectively. The mutations contained 3 transitions, 2 transversions and 1 frameshift; none of them occurred at the site of 'hot-spot' residues (codons 175, 248, 273). The results suggest that: (1) p53 mutation in cerebral PNET tends to show a higher incidence of neuronal differentiation and occurs in the older age group in Taiwan, (2) there was no difference in survival time between the PNET-N and PNET-NN groups (7 months and 6 months) (P = 0.54), and between p53(+) and p53(-) groups (6 months and 7 months) (P = 0.57), and (3) PNET may be an entity of a heterogenous group of tumors with different genetic mechanisms controlling their trends of differential lineage. Further studies are needed to determine the significance of p53 mutations in PNET development, especially the role of carcinogens in the genesis of PNET in Taiwan.
Collapse
Affiliation(s)
- Y S Ho
- Department of Pathology, Chang-Gung Memorial Hospital, Taipei, Taiwan
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Cheng SC, Dravid VP, Goodwin TJ, Shelton RN, Radousky HB. Determination of the valence of Pr in (Eu1.5-xPrxCe0.5)Sr2Cu2NbO10 superconducting compounds by electron-energy-loss spectroscopy. Phys Rev B Condens Matter 1996; 53:11779-11783. [PMID: 9982805 DOI: 10.1103/physrevb.53.11779] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
49
|
McLaughlin TJ, Soumerai SB, Willison DJ, Gurwitz JH, Borbas C, Guadagnoli E, McLaughlin B, Morris N, Cheng SC, Hauptman PJ, Antman E, Casey L, Asinger R, Gobel F. Adherence to national guidelines for drug treatment of suspected acute myocardial infarction: evidence for undertreatment in women and the elderly. Arch Intern Med 1996; 156:799-805. [PMID: 8615714] [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] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Evidence-based guidelines for the treatment of patients with acute myocardial infarction (AMI) have been published and disseminated by the American College of Cardiology and the American Heart Association. Few studies have examined the rates of adherence to these guidelines in eligible populations and the influence of age and gender on highly effective AMI treatments in community hospital settings. METHODS Medical records of 2409 individuals admitted to 37 Minnesota hospitals between October 1992 and July 1993 for AMI, suspected AMI, or rule-out AMI, and meeting electrocardiographic, laboratory, and clinical criteria suggestive of AMI were reviewed to determine the proportion of eligible patients who received thrombolytic, beta-blocker, aspirin, and lidocaine hydrochloride therapy. The effects of patient age, gender, and hospital teaching status on the use of these treatments were estimated using logistic regression models. RESULTS Eligibility for treatment ranged from 68% (n=1627) for aspirin therapy, 38% (n=906) for lidocaine therapy, and 30% (n=734) for thrombolytic therapy to 19% (n=447) for beta-blocker therapy. Seventy-two percent of patients eligible to receive a thrombolytic agent received this therapy; 53% received beta-blockers; 81% received aspirin; and 88% received lidocaine. Among patients ineligible for lidocaine therapy (n=1503), 20% received this agent. Use of study drugs was lower among eligible elderly patients, especially those older than 74 years (thrombolytic agent: odds ratio, 0.2; 95% confidence interval, 0.1 to 0.4; aspirin: odds ratio, 0.4, 95% confidence interval, 0.3 to 0.6; beta-blocker: odds ratio, 0.4; 95% confidence interval, 0.2 to 0.8). Female gender was associated with lower levels of aspirin use among eligible patients (odds ratio, 0.7; 95% confidence interval, 0.6 to 0.9); and there was a trend toward lower levels of beta-blocker and thrombolytic use among eligible women. CONCLUSIONS Use of lifesaving therapies for eligible patients with AMI is higher than previously reported, particularly for aspirin and thrombolytic use in nonelderly patients. Lidocaine is still used inappropriately in a substantial proportion of patients with AMI. Increased adherence to AMI treatment guidelines is required for elderly patients and women.
Collapse
Affiliation(s)
- T J McLaughlin
- Department of Ambulatory Care and Prevention, Harvard Medical School, Boston, Mass, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Chen HR, Hsu MT, Cheng SC. Spheroplast preparation facilitates PCR screening of yeast sequence. Biotechniques 1995; 19:744-6, 748. [PMID: 8588910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Affiliation(s)
- H R Chen
- Institute of Microbiology and Immunology, National Yang Ming University, Taiwan, Republic of China
| | | | | |
Collapse
|