[The efficacy of chemotherapy re-challenge in third-line setting for metastatic colorectal cancer patients: a real-world study]

Objective: To explore the efficacy of chemotherapy re-challenge in the third-line setting for patients with metastatic colorectal cancer (mCRC) in the real world. Methods: The clinicopathological data, treatment information, recent treatment efficacy, adverse events and survival data of mCRC patients who had disease progression after treatment with oxaliplatin-based and/or irinotecan-based chemotherapy and received third-line chemotherapy re-challenge from January 2013 to December 2020 at Tianjin Medical University Cancer Institute and Hospital were retrospectively collected. Survival curves were plotted with the Kaplan-Meier method, and the Cox proportional hazard model was used to analyze the prognostic factors. Results: A total of 95 mCRC patients were included. Among them, 32 patients (33.7%) received chemotherapy alone and 63 patients (66.3%) received chemotherapy combined with targeted drugs. Eighty-three patients were treated with dual-drug chemotherapy (87.4%), including oxaliplatin re-challenge in 35 patients and irinotecan re-challenge in 48 patients. The remaining 12 patients were treated with triplet chemotherapy regimens (12.6%). Among them, as 5 patients had sequential application of oxaliplatin and irinotecan in front-line treatments, their third-line therapy re-challenged both oxaliplatin and irinotecan; 7 patients only had oxaliplatin prescription before, and these patients re-challenged oxaliplatin in the third-line treatment. The overall response rate (ORR) and disease control rate (DCR) reached 8.6% (8/93) and 61.3% (57/93), respectively. The median progression free survival (mPFS) and median overall survival (mOS) were 4.9 months and 13.0 months, respectively. The most common adverse events were leukopenia (34.7%) and neutropenia (34.7%), followed by gastrointestinal adverse reactions such as nausea (32.6%) and vomiting (31.6%). Grade 3-4 adverse events were mostly hematological toxicity. Cox multivariate analysis showed that gender (HR=1.609, 95% CI: 1.016-2.548) and the PFS of front-line treatments (HR=0.598, 95% CI: 0.378-0.947) were independent prognostic factors. Conclusion: The results suggested that it is safe and effective for mCRC patients to choose third-line chemotherapy re-challenge, especially for patients with a PFS of more than one year in front-line treatments.

[A prediction model of pathological complete response in patients with locally advanced rectal cancer after PD-1 antibody combined with total neoadjuvant chemoradiotherapy based on MRI radiomics]

Objective: To construct a prediction model of pathologic complete response (pCR) in locally advanced rectal cancer patients who received programmed cell death protein-1 (PD-1) antibody and total neoadjuvant chemoradiotherapy by using radiomics based on MR imaging data and to investigate its predictive value. Methods: A clinical diagnostic test study was carried out. Clinicopathalogical and radiological data of 38 patients with middle-low rectal cancer who received PD-1 antibody combined with total neoadjuvant chemoradiotherapy and underwent TME surgery from January 2019 to September 2021 in our hospital were retrospectively collected. Among 38 patients, 23 were males and 15 were females with a median age of 68 (47-79) years and 13 (34.2%) a chieved pCR. These 38 patients were stratified and randomly divided into the training group (n=26) and test group (n=12) for modeling. All the patients underwent rectal MRI before treatment. The clinical, imaging and radiomics features of all the patients were collected, and the clinical feature model and radiomics model were constructed. The receiver operating characteristic (ROC) curves of each model were drawn, and the constructed model was evaluated through the area under the curve (AUC), accuracy, sensitivity, specificity, positive predictive value and negative predictive value. Results: There were no significant differences in age, gender, primary location of tumor and postoperative pathology between the two groups (all P>0.05). Forty-one features were extracted from region of interest in each modality, including 9 first-order features, 24 gray level co-occurrence matrix features and 8 shape features. From 38 patients, 41 features were extracted from each imaging modality of baseline and preoperative DWI and T2WI images, totally 164 features. Only 4 features were preserved after correlation analysis between each pair of features and t-test between pCR and non-pCR subjects. After LASSO cross validation, only the first-order skewness of the baseline DWI image before treatment and the volume in the baseline T2WI image before treatment were retained. The area under the curve, sensitivity, specificity, positive and negative predictive values of the prediction model established by applying these two features in the training group and the test group were 0.856 and 0.844, 77.8% and 100.0%, 88.2% and 75.0%, 77.8% and 66.7%, 88.2% and 100.0%, respectively. The decision curve analysis of the radiomics model showed that the strategy of this model in predicting pCR was better than that in treating all the patients as pCR and that in treating all the patients as non-pCR. Conclusion: The pCR prediction model for rectal cancer patients receiving PD-1 antibody combined with total neoadjuvant radiochemotherapy based on MRI radiomics has the potential to be used in clinical screening or rectal cancer patients who can be spared from radical surgery.

[Short-term outcome of programmed cell death protein1 (PD-1) antibody combined with total neoadjuvant chemoradiotherapy in the treatment of locally advanced middle-low rectal cancer with high risk factors]

Objective: Total neoadjuvant chemoradiotherapy is one of the standard treatments for locally advanced rectal cancer. This study aims to investigate the safety and feasibility of programmed cell death protein 1 (PD-1) antibody combined with total neoadjuvant chemoradiotherapy in the treatment of locally advanced middle-low rectal cancer with high-risk factors. Methods: A descriptive cohort study was conducted. Clinicopathological data of 24 patients with locally advanced middle-low rectal cancer with high-risk factors receiving PD-1 antibody combined with neoadjuvant chemoradiotherapy in Gastrointestinal Cancer Center, Unit III, Peking University Cancer Hospital between January 2019 and April 2021 were retrospectively analyzed. Inclusion criteria: (1) rectal adenocarcinoma confirmed by pathology; patient age of ≥ 18 years and ≤ 80 years; (2) the distance from low margin of tumor to anal verge ≤ 10 cm under sigmoidoscopy; (3) ECOG performance status score 0-1; (4) clinical stage T3c, T3d, T4a or T4b, or extramural venous invasion (EMVI) (+) or mrN2 (+) or mesorectal fasciae (MRF) (+) based on MRI; (5) no evidence of distant metastases; (6) no prior pelvic radiation therapy, no prior chemotherapy or surgery for rectal cancer; (7) no systemic infection requiring antibiotic treatment and no immune system disease. Exclusion criteria: (1) anticipated unresectable tumor after neoadjuvant treatment; (2) patients with a history of a prior malignancy within the past 5 years, or with a history of any arterial thrombotic event within the past 6 months; (3) patients received other types of antitumor or experimental therapy; (4) women who were pregnant or breast-feeding; (5) patients with any other concurrent medical or psychiatric condition or disease; (6) patients received immunotherapy (PD-1 antibody). The neoadjuvant therapy consisted of three stages: PD-1 antibody (sintilimab 200 mg, IV, Q3W) combined with CapeOx regimen for three cycles; long-course intensity modulated radiation therapy (IMRT) with gross tumor volume (GTV) 50.6 Gy/CTV 41.8 Gy/22f; CapeOx regimen for two cycles after radiotherapy. After oncological evaluation following the end of the third stage of treatment, surgery or watch and wait would be carried out. Surgical safety, histopathological changes and short-term oncological outcome were analyzed. Results: There were 15 males and 9 females with a median age of 65 (47-78) years. Median distance from the lower margin of the tumor to the anal verge was 4 (3-7) cm. The median maximal diameter of the tumor was 5.1 (2.1-7.5) cm. Twenty patients were cT3, 4 were cT4, 8 were cN1, 5 were cN2a, 11 were cN2b. Ten cases were MRF (+) and 10 were EMVI (+). All the patients were mismatch repair proficient (pMMR). During the neoadjuvant treatment period, 6 patients (25.0%) developed grade 1-2 treatment-related adverse events, including 3 immune-related adverse events. As of April 30, 2021, 20 patients (83.3%, 20/24) had received surgical resection, including 19 R0 resections and 16 sphincter-preservation operations. Morbidity of postoperative complication was 25.0% (5/20), including 2 cases of Clavien-Dindo grade II (1 of anastomotic bleeding and 1 of pseudomembranous enteritis), 3 cases of grade I anastomotic stenosis. Pathological complete response (pCR) rate was 30.0% (6/20) and major pathological response rate was 20.0% (4/20). None of Ras/Raf mutants had pCR or cCR (0/5), while 6 of 17 Ras/Raf wild-type patients had pCR and 3 had cCR, which was significantly higher than that of Ras/Raf mutants (P<0.01). Nine of 16 patients with Ras/Raf wild-type and differentiated adenocarcinoma had pCR or cCR. Among other 4 patients without surgery, 3 patients preferred watch and wait strategy because their tumors were assessed as clinical complete response (cCR), while another one patient refused surgery as the tumor remained stable. After a median follow-up of 11 (6-24) months, only 1 patient with signet ring cell carcinoma had recurrence. Conclusions: PD-1 antibody combined with total neoadjuvant chemoradiotherapy in the treatment of locally advanced rectal cancer has quite good safety and histopathological regression results. Combination of histology and genetic testing is helpful to screen potential beneficiaries.

Cdc25C/cdc2/cyclin B, raf/MEK/ERK and PERK/eIF2α/CHOP pathways are involved in forskolin-induced growth inhibition of MM.1S cells by G2/M arrest and mitochondrion-dependent apoptosis

Multiple myeloma (MM) remains an incurable hematological malignancy characterized by proliferation and accumulation of plasma cells in the bone marrow. Innovative and effective therapeutic approaches that are able to improve the outcome and the survival of MM sufferers, especially the identification of novel natural compounds and investigation of their anti-MM mechanisms, are needed. Here, we investigated the effects and the potential mechanisms against MM of forskolin, a diterpene derived from the medicinal plant Coleus forskohlii, in MM cell line MM.1S. CCK-8 assay showed that forskolin significantly inhibited MM.1S cells viability in a time- and dose-dependent manner. Furthermore, we demonstrated that forskolin induced G2/M phase arrest with a remarkable increase of p-cdc25c, p-cdc2, and a decrease of cyclin B1, indicating the suppression of cdc25C/cdc2/cyclin B pathway. Moreover, we found that forskolin induced mitochondrion-dependent apoptosis which was accompanied by the increase of pro-apoptotic proteins Bax, Bad, Bim and Bid, the decrease of anti-apoptotic proteins Bcl-2 and Bcl-xl, the changes of the mitochondrial membrane potential (MMP) and increase of cleaved caspase-9, cleaved caspase-3 and cleaved PARP. Of note, we demonstrated that forskolin induced a decrease of p-C-Raf, p-MEK, p-ERK1/2 and p-p90Rsk, and an increase of p-PERK, p-eIF2α and CHOP, which indicated that the inhibition of Raf/MEK/ERK pathway and activation of PERK/eIF2α/CHOP pathway were involved, at least partially, in forskolin-induced MM.1S cells apoptosis. These findings confirm the anti-MM action of forskolin and extend the understanding of its anti-MM mechanism in MM.1S cells, as well as reinforcing the evidence for forskolin as a natural chemotherapeutic compound against MM.

Lycorine hydrochloride induces reactive oxygen species-mediated apoptosis via the mitochondrial apoptotic pathway and the JNK signaling pathway in the oral squamous cell carcinoma HSC-3 cell line

Poor drug efficacy is a prominent cause of oral squamous cell carcinoma (OSCC) treatment failure. Although increased efforts in developing OSCC therapeutic strategies have been achieved in recent decades, the 5-year survival rate of patients with OSCC remains poor and effective drugs to treat OSCC are lacking. The aim of the present study was to investigate the apoptotic effect caused by lycorine hydrochloride (LH) and to identify its mechanism in the OSCC HSC-3 cell line. The findings demonstrated that LH effectively induced HSC-3 cell apoptosis and cell cycle arrest at the G₀/G₁ phase, resulting in the inhibition of cell proliferation. Furthermore, it was found that LH increased reactive oxygen species (ROS) production, triggered mitochondrial membrane potential (MMP) disorder, enhanced the protein expression levels of Bax, Bim, cleaved caspase-9, caspase-3 and poly(ADP-ribose) polymerase 1 and decreased Mcl-1 expression. The protein expression levels of important members of the JNK signaling pathway, including phosphorylated (p)-JNK, p-mitogen-activated protein kinase kinase 4 and p-c-Jun, were significantly increased in LH-treated cells, accompanied by an increase in ROS. However, N-acetyl cysteine (NAC), a potent antioxidant, reversed the upregulated mRNA expression of c-Jun, as well as the enhanced ROS production, the disorder of MMP and the apoptosis of HSC-3 cells induced by LH. These results suggested that LH may induce HSC-3 cell apoptosis via the ROS-mediated mitochondrial apoptotic pathway and the JNK signaling pathway, which indicated that LH may be a potential drug candidate for anti-OSCC therapy.

[Application of imaging diagnosis in watch and wait strategy for locally advanced rectal cancer patients after neoadjuvant therapy]

After neoadjuvant chemoradiotherapy(nCRT), 15%-40% of rectal cnacers has a pathological complete response (pCR), with non-malignant cells demonstrated in histological assessment of the surgical resection specimen. Since these patients have excellent oncological outcomes, there has been a rapidly growing interest in organ preservation for those who achieve a clinical complete response (cCR), that is "Watch and Wait strategy" (W&W). One of the major challenges in the W&W of rectal cancer is the careful and precise selection of patients suitable for this approach. The published series on W&W has all used different modalities to assess response post nCRT, including the MSKCC's three-tiered evaluation plan and Mercury's mrTRG criteria. Except significant heterogeneous results, the evidence available comes mostly from retrospective cohort studies, furthermore, there is a lack of data of long-term outcomes. How to accurately screen pCR patients preoperatively is an important and difficult issue of clinical concern.

[Genotype and evolution of hantavirus in Tiantai of Zhejiang province, 2011-2018]

Objective: By investigating the genotype and evolutionary variation of hantavirus (HV) in Tiantai county, a national surveillance site for hemorrhagic fever with renal syndrome (HFRS) was set in Zhejiang province, from 2011 to 2018, to reveal the molecular epidemiological characteristics of hantavirus (HV) in Tiantai. Methods: Total RNA was extracted from ultrasound treated HV antigen- positive rat lung samples in Tiantai from 2011 to 2018. After cDNA was prepared, nested PCR was used to amplify partial sequence of M fragments by using specific primers of HV. The sequences of HV in Tiantai from 2011 to 2018 were compared with other known HV sequences in order to identify the genotype and analyze the evolution and variation of the virus. Results: In 67 HV antigen-positive lung specimens, 31 were positive in nested PCR amplification with type-specific primers, including 30 Hantaan virus (HTNV) positive samples, 1 Seoul virus (SEOV) positive sample, and all the 31 samples were from Apodemus agrarius. The phylogenetic tree based on partial M segment was divided into monophyletic group, 30 strains were distributed in HTNV group and 1 was in SEOV group. The HTNV strain Tiantai T2018-130 was independently in one branch, sharing 84.8%-87.9% homology with other strains both at home and abroad, including 29 strains in HTNV group in Tiantai. The other 29 HTNV strains in Tiantai showed closer relationship. The SEOV strain T2016-31 from Apodemus agrarius showed closer relationship with previous strains of SEOV, Tiantai ZT71, ZT10 and Z37 strains of Wenzhou, Zhejiang province. Conclusions: HTNV, the main genotype of HV in Tiantai of Zhejiang province, showed obvious geographic clustering, but the strain T2018-130 was distinct from the others in Tiantai. Meanwhile, by sequence analysis, we confirmed that The SEOV strain T2016-31 existed in in Apodemus agrarius, indicating there was a phenomenon of "spillover" between virus and host in SEOV evolution.

[Application value of colonoscopic assessment in "watch and wait" strategy for mid-lower rectal cancer after neoadjuvant chemoradiotherapy]

Objective: To investigate the value of colonoscopic assessment in "watch and wait" strategy for mid-lower rectal cancer after neoadjuvant chemoradiotherapy (nCRT). Methods: A single-center retrospective case series study was performed. Database of mid-lower rectal cancer patients at Department of Gastrointestinal Oncology, Peking University Cancer Hospital & Institute from March 2011 to June 2017 was retrieved. Inclusion criteria: (1) nCRT was completed (50.6 Gy/22 f, plus oral capecitabine); (2) radical surgery was performed within 12 weeks after nCRT treatment; (3) clinical response to nCRT was determined as clinical complete response (cCR) or near-cCR. Patients who did not undergo colonoscopy and MRI in our center during initial assessment and follow-up, or whose colonoscopy data were unable to re-evaluated, were excluded. Initial evaluation of nCRT response was carried out between 6 and 16 weeks after nCRT. The results of endoscopy (eCR, near-eCR and non-eCR) and MRI (mCR, near-mCR and non-mCR) were compared to local lesion relapse during follow-up. The consistency of the results of colonoscopy and MRI was evaluated by Kappa test (Kappa value of 0.21 to 0.40 indicates general consistency, 0.41 to 0.60 moderate consistency, and 0.61 to 0.80 high consistency). The non-regrowth disease-free survival (NR-DFS) curves of the eCR group and the near-eCR group were plotted by Kaplan-Meier method and compared by log-rank test. Clinical significance of colonoscopy examination in the following "watch and wait" strategy during follow-up period was analyzed. Results: A total of 32 patients were enrolled in the study, including 21 (65.6%) males and 11 (34.4%) females with a median age of 57 years old. The differentiated type of rectal cancer included 1 (3.1%) case of well-differentiated, 26 (81.2%) of moderately differentiated and 5 (15.6%) of poorly differentiated. Clinical stage of the patients included 9 (28.1%) cases of T2-3N0 and 23 (71.9%) of T2-3N+. Median follow-up period was 48 (18 to 80) months. The local regrowth rate was 34.4% (11/32) and median interval of local regrowth was 10.0 (4 to 37) months. Initial colonoscopy evaluation was carried out at a median time of 9 (5 to 19) weeks after nCRT was completed. According to endoscopic findings, patients were divided into 3 groups, including 15 cases in eCR group, 15 cases in near-eCR group and 2 cases in non-eCR group. According to the appearance of MRI, patients were divided into 3 groups, including 8 cases in mCR group, 21 cases in near-mCR group and 3 cases in non-mCR group. The regrowth rate of eCR group was lower than that of mCR group (1/15 vs. 1/8) without significant difference (P=1.000). The regrowth rate of near-eCR group was higher than that of near-mCR group [9/15 vs. 42.9% (9/21)] without significant difference as well (P=0.500). The consistency between colonoscopy and MRI in response evaluation of cCR or near-cCR after nCRT was unsatisfactory (Kappa=0.341, P=0.011). After initial evaluation, 31 patients underwent watch and wait strategy, and 1 underwent local resection. The 1- and 3-year NR-DFS in the eCR group was both 100%, which was higher than that in the near-eCR group (53.3% and 38.9%, respectively), and the difference was statistically significant (P=0.001). During watch and wait period, 11 cases developed local regrowth by colonoscopy examination and the biopsy result included 4 case of high-grade intraepithelial neoplasia (HIN), 6 cases of adenocarcinoma and 1 case of chronic mucosal inflammation. Meanwhile lateral developmental tumor of ascending colon in 1 case and of sigmoid in a case was found by colonoscopy and confirmed as HIN by postoperative pathology. Besides, 4 cases developed colonic multiple adenoma and all underwent endoscopic resection. Conclusion: Colonoscopy examination plays an important role in both initial assessment and regrowth monitoring during watch and wait strategy after nCRT treatment.

Enhanced Cell Response to Zirconia Surface Immobilized with Type I Collagen

Zirconia (ZrO₂) dental implants provide good biocompatibility, have good corrosion resistance, and have a color that is similar to that of natural teeth. Unfortunately, ZrO₂ is a bioinert material and therefore achieves osseointegration difficultly. In this study, we sought to enhance osseointegration by producing rough ZrO₂ surfaces that contain hydroxyl groups (designated ZSA) through the use of sandblasting in conjunction with alkaline treatment. We immobilized type I collagen on ZSA surfaces using the natural cross-linker, procyanidin. Our results further showed that surfaces produced in ZSA-P/C featured more and steadier type I collagen than surfaces produced in ZSA-C. The ZSA-P/C also presented superior cell responses in terms of adhesion, proliferation, and mineralization of human bone marrow mesenchymal stem cells. The enhanced cell responses in the ZSA-P/C were induced through the prolonged activation of focal adhesion kinase, AKT (the phosphoinositide 3-kinase pathway), and p38 (the mitogen-activated protein kinase pathway). The simple and novel approach to immobilize type I collagen on roughened ZrO₂ surfaces presented in this article can likely benefit dental implant applications.

[Application of decision curve on evaluation of MRI predictive model for early assessing pathological complete response to neoadjuvant therapy in breast cancer]

Objective: To construct a dynamic enhanced MR based predictive model for early assessing pathological complete response (pCR) to neoadjuvant therapy in breast cancer, and to evaluate the clinical benefit of the model by using decision curve. Methods: From December 2005 to December 2007, 170 patients with breast cancer treated with neoadjuvant therapy were identified and their MR images before neoadjuvant therapy and at the end of the first cycle of neoadjuvant therapy were collected. Logistic regression model was used to detect independent factors for predicting pCR and construct the predictive model accordingly, then receiver operating characteristic (ROC) curve and decision curve were used to evaluate the predictive model. Results: ΔArea(max) and Δslope(max) were independent predictive factors for pCR, OR=0.942 (95%CI: 0.918-0.967) and 0.961 (95%CI: 0.940-0.987), respectively. The area under ROC curve (AUC) for the constructed model was 0.886 (95%CI: 0.820-0.951). Decision curve showed that in the range of the threshold probability above 0.4, the predictive model presented increased net benefit as the threshold probability increased. Conclusions: The constructed predictive model for pCR is of potential clinical value, with an AUC>0.85. Meanwhile, decision curve analysis indicates the constructed predictive model has net benefit from 3 to 8 percent in the likely range of probability threshold from 80% to 90%.

Risk of complications of ultrasound-guided renal biopsy for adult and pediatric patients with systemic lupus erythematosus

Objective The objective of this paper is to identify the risk of complications of real-time ultrasound-guided renal biopsy in adult and pediatric patients with systemic lupus erythematosus (SLE). Materials and methods This retrospective study examined outcomes of 296 renal biopsy procedures in 275 SLE patients. Imaging-confirmed symptomatic hematoma was regarded as a major complication when intervention (blood transfusion, angiographic embolization, or surgery) was required or as a minor complication otherwise. Clinical and laboratory data were compared between groups with or without complications after initial or subsequent renal biopsy. Binary logistic regressions were used to evaluate complication risk of initial renal biopsy. Results Overall complication rate of initial renal biopsy was 8.7% (major: 2.9%, minor: 5.8%). Three patients expired from pulmonary hemorrhage, thrombotic microangiopathy, and pneumonia. Pediatric SLE patients tended to have a higher rate of major complications (12.5%) than adult patients (2.3%). According to multivariable analysis results, elevated serum creatinine (SCr) level (OR 1.45; 95% CI 1.17-1.81 per mg/dl), prolonged prothrombin time (PT) (OR 2.2; 95% CI 1.05-4.62 per second), and thrombocytopenia (OR 4.3; 95% CI 1.56-11.9) increased overall complication risk of initial renal biopsy. Age < 18 years (OR 8.43; 95% CI 1.21-58.8), thrombocytopenia (OR 16.4; 95% CI 2.44-110.5), and elevated SCr level (OR 1.97; 95% CI 1.36-2.86 per md/dl) increased risk of major complications. Thrombocytopenia, prolonged PT, and elevated SCr level were associated with complications after subsequent renal biopsy (all p = 0.01). Conclusions SLE patients, particularly patients under 18 years old or with elevated SCr level, prolonged PT, or thrombocytopenia, have an increased risk of complications after initial or subsequent renal biopsy.

[Recombinant expression of hantaan virus protein N with application of Western-blot in detecting anti-hantavirus antibody]

Objective: S gene of hantavirus(HV) was expressed in insect cells by genetic engineering technology. The expression product of S gene was used as antigen to detect anti-HV specific antibody IgG in serum. Methods: Gene encoding NP of the strain HV-Z10 was amplified by PCR and then its eukaryotic expression system rBAC-Z10S-TN was constructed by using the routine genetic engineering method. SDS-PAGE was applied to measure the expression of rNP.Ion-exchange plus Ni-NTA-affinity chromatography was performed to purify the recombinant product. Indirect immuno-fluorescence assay (IFA) was used to determine the specific immune-reactivity of rNP. WB assay was established to detect the serum samples from 95 confirmed HFRS patients. Parameters related to the outcomes of detection were compared with the routine HV-IgG IFA method. Results: rBAC-Z10S-TN was able to express rNP with high efficiency. The purified rNP only showed a single protein fragment in the gel after SDS-PAGE. HV IgG could efficiently recognize rNP and hybridize with the recombinant protein. 97.67% of the serum samples from the HFRS patients were positive confirmed by WB. Conclusions: We successfully constructed a high efficient prokaryotic expression system of NP encoding gene from hantavirus strain HV-Z10. WB assay which was established in this study could be used as a new serological test for HFRS diagnosis, thanks to the simplicity, safety, sensitivity and specificity of this method.

[Risk factors for central neck lymph node metastases of papillary thyroid carcinoma]

Objective: To investigate the impact factors for central neck lymph node metastases(CLNM) of papillary thyroid carcinoma(PTC). Methods: A total of 498 patients with PTC who underwent total or hemi-thyroidectomy plus central neck lymph node dissection between January 2014 and July 2016 were included. Univariate and multivariate analyses were performed to identify clinicopathological characteristics, thyroid function parameters and US findings that associated with CLNM of PTC. A nomogram was developed to predict the probability of CLNM. The receiver operating characteristic curve(ROC) was used to estimate the efficiency of the nomogram. Results: Among 498 patients, 284 patients were affected by CNLM. The sensitivity and specificity of US in predicting PTC metastasis in the central neck were 31.3% and 88.3%, respectively. Univariate and multivariate analyses showed that gender, age, number and size of suspicious malignant nodules in thyroid, and suspicious lymph node metastasis detected by ultrasonography were independently correlated with CLNM. The ROC showed that the AUC was 0.748, with sensitivity of 80.8%, and specificity of 59.8%. Conclusions: Gender, age, number and size of suspicious malignant nodules in thyroid, suspicious lymph node metastasis were predictive factors for CLNM in patients with PTC. The nomogram developed based on related factors with CLNM is more sensitive than sonographic central neck lymph node features in predicting the probability of CLNM.

[Association between ambulatory arterial stiffness index with left ventricular mass index in the elderly hypertensive patients]

Objective: To investigate the relationship between ambulatory arterial stiffness index (AASI) and left ventricular mass index (LVMI) in the elderly hypertensive patients. Methods: This study population consisted of 332 elderly hypertensive patients, who hospitalized in our department from January 2012 to December 2014.AASI was calculated from 24 h ambulatory BP monitoring recordings and LVMI from echocardiography examination.According to the median value of AASI, patients were divided to less than the AASI median group (low AASI group) and equal to or above the AASI median group (high AASI group). Differences between two groups were evaluated using the Student's t-test and Chi-square test.Univariate association was assessed by the Pearson correlation analyses.Multivariate linear regression models were performed to analyze the correlation between AASI and LVMI. Results: LVMI was significantly higher in high AASI group compared with low AASI group ( (115.91±21.36) g/m² vs.(104.11±17.24) g/m^2,P=0.008). Pearson correlation analyses showed that AASI and 24 h pulse pressure were positively correlated to LVMI (r=0.332, P<0.001; r=0.169, P=0.002). In multivariate linear regression model, AASI(β=44.48, P<0.001), LDL-C(β=-5.97, P<0.001) and UA (β=0.02, P=0.045)showed significant association with LVMI. Conclusion: AASI independently associated with LVMI, and AASI might be one predictor of left ventricular hypertrophy in hospitalized elderly hypertensive patients.

A point-prevalence survey of healthcare-associated infection in fifty-two Chinese hospitals

BACKGROUND

Healthcare-associated infection (HCAI) represents a major problem for patient safety worldwide.

AIM

To demonstrate the prevalence, causative agents, and risk factors for HCAI in Chinese hospitals.

METHODS

A one-day point-prevalence survey was conducted in 52 Chinese hospitals between October 2014 and March 2015. A web-based software system was developed for data entry and management.

FINDINGS

Among 53,939 patients surveyed, the prevalence of patients with at least one HCAI was 3.7%. Of 2182 HCAI episodes, the most frequently occurring types were lower respiratory tract infections (47.2%), followed by urinary tract infection (12.3%), upper respiratory tract infection (11.0%), and surgical site infection (6.2%). The prevalence of patients with at least one HCAI in critical care units was highest (17.1%). Device-associated infections, including ventilator-associated pneumonia, catheter-associated urinary tract infection, and central catheter-associated bloodstream infection, accounted for only 7.9% of all HCAIs. The most frequently isolated micro-organisms were Pseudomonas aeruginosa [206 infections (9.4%)], Acinetobacter baumannii [172 infections (7.9%)], Klebsiella pneumoniae [160 infections (7.3%)], and Escherichia coli [145 infections (6.6%)]. Of the survey patients (18,206/53,939), 33.8% were receiving at least one antimicrobial agent at the time of the survey. Risk factors for HCAI included older age (≥80 years), male gender, days of hospital admission, admission into a critical care unit, and device utilization.

CONCLUSION

Our study suggests that the overall prevalence of HCAI in surveyed Chinese hospitals was lower than that reported from most European countries and the USA. More attention should be given to the surveillance and prevention of non-device-associated HCAI in China.

Serum uric acid level and left ventricular hypertrophy in elderly male patients with nonvalvular atrial fibrillation

BACKGROUND AND AIMS

Recent studies have suggested that serum uric acid (SUA) induces oxidative stress and inflammation, which are involved in the mechanism of cardiac hypertrophy. In patients with atrial fibrillation (AF), comorbidity of left ventricular hypertrophy (LVH) exacerbates cardiac function. In this study, we investigated the association between SUA and cardiac hypertrophy in AF patients.

METHODS AND RESULTS

Initially, 1296 consecutive elderly patients (age >60) with nonvalvular AF were retrospectively selected from the inpatient clinic between January 2012 and April 2015. Demographic, clinical, and echocardiographic characteristics were carefully recorded. The final study population was 577 patients. The mean SUA level was significantly higher in patients with LVH than those without LVH. Compared with the non-LVH group, the LVH group was older, had a higher percentage of female patients, and had lower hemoglobin levels and estimated glomerular filtration rates. Patients in the LVH group also had a higher rate of coronary heart disease and fewer had history of radiofrequency ablation compared with the non-LVH group. In the hyperuricemia group, B-type natriuretic peptide levels, left atrial diameter, left ventricular mass index, and percentage of NYHA (New York Heart Association) class III/IV were significantly higher than the SUA normal group. Multivariate logistic regression analysis indicated the independent risk factors for LVH in elderly AF patients included SUA, age, male sex, the presence of coronary heart disease, and diuretic therapy. Subgroup analysis identified SUA as a significant risk factor associated with LVH in men.

CONCLUSIONS

SUA was independently associated with LVH in elderly male patients with nonvalvular AF.

Practices and thinking of laboratory detection in the aid to West Africa to fight against Ebola

BACKGROUND

The outbreak of Ebola virus disease in West Africa has brought great disaster to the people's health in affected countries. China dispatched first group of public health experts and medical staff to Sierra Leone in September 2014 to fight Ebola.

METHODS

To systematically collect huge amount of primary data, and to make analysis, draw conclusions and lessons in terms of six aspects, respectively as training before departure, local disease information, track of epidemic situation, transformation of temporary laboratory, detection of Ebola virus samples as well as assessment through single blind test.

RESULTS

1) Our team has launched preparatory works in advance before going to Sierra Leone. 2) Malaria is the country's severest infectious disease. 3) Observation centers were overcrowded with large number of suspected cases being inspected, implying high risk of nosocomial infection. 4) A BSL-II laboratory with 3 work areas and 2 buffer areas was built, achieving several major functions within 6 days. 5) Confirmed by South African Raqqa laboratory, our detection accuracy reached 100%. 6) At one week before return, the daily average sample amount of our team reached 66 cases and our detection capability was equivalent to that of USA.

CONCLUSIONS

Successful experience from fighting against Ebola in Sierra Leone could be summarized as: 1) Optimized processes and scientific security measures are prerequisite to improving the detection ability. 2) The close collaboration between laboratory and observation center has created a new model of China's foreign aid. 3) Comprehensive information investigation and training lay a solid foundation for the successful completion of tasks.

Association between dietary intake of folate and MTHFR and MTR genotype with risk of breast cancer

We investigated the association between dietary intake of folate, vitamin B6, and the 5,10-methylenetetrahydrofolate reductase (MTHFR) genotype with breast cancer. A matched case-control study was conducted, and 413 patients with newly diagnosed and histologically confirmed breast cancer and 436 controls were recruited. Folate intake, vitamin B6, and vitamin B12 levels were calculated, and the MTHFR C677T and A1298C and MTR A2756G polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism. Breast cancer cases were generally older, older at first live birth, and younger at menarche, had a higher body mass index, were smokers, had higher energy intake, and more first-degree relatives with breast cancer as well as more live births compared to controls. With respect to energy intake, we found that higher energy intake were more likely to increase the risk of breast cancer. The MTHFR 667TT genotype was associated with a moderately increased risk of breast cancer when compared with the CC genotype, and a significant odds ratio (OR; 95% confidence interval, CI) was found (OR = 1.70, 95%CI = 1.06-2.73). Individuals carrying T allele were associated with higher risk of breast cancer when compared with C allele (OR = 1.34, 95%CI = 1.06-1.70). We did not find a significant effect of the MTHFR A1298C and MTR A2756G on the risk of breast cancer. We did not find any association between folate intake and MTHFR C677T polymorphisms. In conclusion, we found that the MTHFR C667T polymorphism is associated with the risk of breast cancer, indicating that this genotype plays a role in breast cancer development.

Parathyroid hormone-related peptide (PTHrP): prokaryotic expression, purification, and preparation of a polyclonal antibody

Parathyroid hormone-related peptide (PTHrP) plays important roles in promoting cancer occurrence and in the development of bone metastases. To increase our knowledge of the biological functions of PTHrP, the prokaryotic expression vector pET-PTHrP was successfully constructed and the His-PTHrP fusion protein was expressed in Escherichia coli. Anti-PTHrP polyclonal antibody was then prepared from rabbits. Finally, the goat tissue expression profile of PTHrP was analyzed by Western blot with the anti-PTHrP polyclonal antibody. The results showed that the expression of PTHrP in goat mammary glands was significantly higher than that in other organs. This indicates that PTHrP may play important roles in the goat mammary gland. The antibody prepared will be a useful tool for detecting PTHrP and will be valuable in future studies investigating the role of PTHrP in calcium metabolism in the goat model.

Magnetically driven metal-insulator transition in NaOsO3

The metal-insulator transition (MIT) is one of the most dramatic manifestations of electron correlations in materials. Various mechanisms producing MITs have been extensively considered, including the Mott (electron localization via Coulomb repulsion), Anderson (localization via disorder), and Peierls (localization via distortion of a periodic one-dimensional lattice) mechanisms. One additional route to a MIT proposed by Slater, in which long-range magnetic order in a three dimensional system drives the MIT, has received relatively little attention. Using neutron and x-ray scattering we show that the MIT in NaOsO(3) is coincident with the onset of long-range commensurate three dimensional magnetic order. While candidate materials have been suggested, our experimental methodology allows the first definitive demonstration of the long predicted Slater MIT.

A novel high-throughput scanning microscope for label-free detection of protein and small-molecule chemical microarrays

We describe a novel scanning optical microscope based on a polarization-modulated nulling ellipsometry. The new microscope employs a combination of scanning mirror and sample translation and thus enables high-throughput label-free detection of biomolecular microarrays with more than 10 000 protein or small-molecule targets. For illustration, we show the image of a 2760-spot protein microarray on a functionalized glass slide obtained with such a microscope. The new scanning microscope is also capable of determining, in parallel, the real-time binding kinetics of multiple molecular species under aqueous conditions.

Thoracoscopic robot-assisted bronchoplasty

BACKGROUND

In robotic surgery, the ideal position of the system, as well as the optimal working angles and the proper positioning of the thoraco ports position is very important. No robot-assisted bronchoplasty has been reported. Our study describes use of the da VinciTM surgical system (Intuitive Surgical, Inc.) for robotic sleeve upper lobectomy in a human fresh cadaver.

METHODS

A male cadaver was placed in the left lateral decubitus position. After thoracoscopic upper lobectomy was performed through the working port and the two ports, the robotic system was then set up behind the cadaver. The working port allowed introduction of the optical scope and the robotic surgical arms were inserted into the thoraco ports. The right bronchus was dissected and wedge was cut out with the robotic scissors. After standard lymph node dissection, end-to-end bronchial anastomosis was performed with robotic instruments. Once the anastomosis was complete, air leakage was checked with saline solution placed in the pleural cavity.

RESULTS

Thoracoscopic robot-assisted bronchoplasty was performed successfully.

CONCLUSIONS

In evaluating various positions of the system we demonstrated that our technique is sufficient approaches to robotic bronchoplasty. This procedure offers specific advantages over conventional bronchoplasty with accuracy and safety.

A carotid stenosis model in canines

A carotid stenosis model was developed in canines in order to study the effects of systemic blood pressure and hemodilution on cerebrovascular perfusion and metabolism during cardiopulmonary bypass in the setting of significant coexistent inflow stenosis. Under general anesthesia, through a low midline neck incision, the carotid sheath was entered and the carotid artery was isolated and retracted medially. The vertebral artery could be identified posterolaterally. After ligating the vertebral artery with a 00 silk tie, carotid stenosis was created by tying bilateral carotid arteries over an 18-gauge needle using a 00 silk tie. The needle was then removed, leaving a tight stenosis. To determine the degree of stenosis, arteriograms were performed, revealing high-grade lesions of greater than 90% stenosis in the carotid arteries and absence of flow through the vertebral arteries. Cerebral blood flow studies during cardiopulmonary bypass (CPB) were performed, revealing a significant decline. Carotid arteries were harvested at the conclusion of the experiments, revealing tight lesions on direct inspection. The mean gradient measured across stenotic segments was >25 mm Hg. In conclusion, a carotid stenosis model can be created successfully in dogs by ligating the vertebral arteries bilaterally and simply using the shaft of a needle to standardize the lumen size of the carotid arteries. We found the diameter of an 18-gauge needle sufficient to produce stenoses of greater than 90% as evidenced by arteriograms.

[ENU induced mutagenesis-large-scale study of gene mutagenesis and function]

ENU mutagenesis is becoming one of the most powerful approaches for large-scale study of gene function. The mechanism of ENU mutagenesis, factors that affect mutation rates, the strategies of the ENU mutagenesis, screening for the phenotypes, related researches and recent progresses were introduced.

Transformation of nonvascular acellular tissue matrices into durable vascular conduits

BACKGROUND

Prosthetic grafts commonly used for vascular reconstruction are limited to synthetics and cross-linked tissue grafts. Within these devices, graft infections are common, compliance mismatch is significant, and handling qualities are poor. Natural biological tissues that are unfixed have been shown to resist infections and be durable and compliant. A natural biological matrix that could be remodeled appropriately after implantation would be a desirable graft for vascular reconstruction.

METHODS

SynerGraft tissue engineering strategies have been used to minimize antigenicity and produce stable unfixed vascular grafts from nonvascular bovine tissues. These grafts have replaced the abdominal aortas of 8 dogs that have been followed for up to 10 months.

RESULTS

Early evaluation indicates rapid recellularization by recipient smooth muscle actin positive cells, which become arranged circumferentially, into the media. Arterioles were present in the adventitial areas and endothelial cells were seen to cover lumenal surfaces. After 10 months, grafts were patent and not aneurysmal.

CONCLUSIONS

These data indicate that SynerGraft processing of animal tissues is capable of producing stable vascular conduits that exhibit long-term functionality in other species.

Differences in myocardial and peripheral VEGF and KDR levels after acute ischemia

BACKGROUND

Recent clinical use of vascular endothelial growth factor (VEGF) in the treatment of both myocardial and peripheral ischemia has suggested the possibility of tissue specific coregulation of VEGF and its receptors (eg, kinase domain region [KDR]). The present study was performed to detect the relationship between VEGF and KDR protein levels after acute myocardial and peripheral ischemia.

METHODS

Eleven dogs were divided into two groups: peripheral ischemia (n = 6, ligation of major limb arteries) and myocardial ischemia (n = 5, circumflex artery ligation). Muscle biopsy specimens were taken from the perfusion territories of the occluded circumflex artery and limb arteries 3 hours and 6 hours after ligation. Protein levels were determined using Western blot analysis.

RESULTS

In myocardium, VEGF levels increased on average eightfold from baseline (p < 0.05) both 3 hours and 6 hours after occlusion, whereas myocardial KDR levels dropped by about 60% at 3 hours and 80% at 6 hours (p < 0.05). With limb ischemia, both VEGF and KDR levels were significantly elevated at 3 hours.

CONCLUSIONS

In acute ischemia, regulation of VEGF and KDR may be controlled differently in cardiac and skeletal muscle. Myocardial KDR levels showed a significant decrease from baseline compared with a significant rise with peripheral ischemia.

A paradox of cerebral hyperperfusion in the face of cerebral hypotension: the effect of perfusion pressure on cerebral blood flow and metabolism during normothermic cardiopulmonary bypass

BACKGROUND

The purpose of this study was to determine the impact of perfusion pressure on cerebral blood flow (CBF) and metabolism during normothermic cardiopulmonary bypass (CPB) and after weaning.

MATERIALS AND METHODS

Two groups of mongrel dogs were studied (Group A, CPB perfusion at 50 mm Hg, n = 6; and Group B, CPB perfusion at 100 mm Hg, n = 6). All animals underwent 2 h of normothermic bypass at cardiac indexes >2.1 L/min/m2 and were weaned from pump, maintained at pressures >75 mm Hg, and followed for an additional 2 h.

RESULTS

In both groups CBF increased over 85% from baseline, in proportion to the hemodilution during the initiation of CPB. Intracranial pressure increased moderately in both groups during CPB, compromising CBF at 1 h in Group A, but not in Group B. The Group A cerebral metabolic rate for oxygen (CMRO2), however, remained unchanged as the percentage of oxygen extraction increased to compensate for the decreased CBF. During recovery, temperature, mean arterial pressure, and cerebral perfusion pressure were not significantly different between the two groups. However, the CBF, percentage of oxygen extracted, and CMRO2 were significantly lower in Group A.

CONCLUSIONS

Normothermic CPB initiated with a crystalloid prime and performed at the lower end of a 50-70 mm Hg perfusion window resulted in a highly significant increase in CBF in order to compensate for hemodilution, while at the same time reduced the perfusion pressure available to supply the increased CBF. Together, these two events create a hemodynamic paradox of hyperperfusion in the face of hypotension. The reduction in CMRO2 in Group A is yet to be explained but seems to remain coupled to CBF and could represent a previously undescribed protective mechanism of hibernating cerebral tissue, similar to the phenomena of ischemic preconditioning in the heart, where cerebral tissue is stimulated to lower metabolism in response to inadequate CBF.

Successful small diameter arterial grafting using cryopreserved allograft arteries

Intimal hyperplasia (IH) limits the long-term success of veins as arterial grafts. IH occurs in veins partly as an adaptive process to arterial pressure conditions. The authors have previously reported early success with cryopreserved (CP) saphenous veins as aortocoronary bypass grafts, and they have hypothesized that CP arterial segments were already structurally adapted for arterial conditions. Six femoral arterial segments were harvested from three adult donor dogs, and cryopreserved. The segments were thawed and implanted into six recipient dogs, in end-to-end fashion, as interpositional grafts in the femoral artery. A similar length of native femoral artery was removed from the implant site and grafted in the contralateral femoral artery of the same animal to serve as native autograft-matched controls. Grafts were harvested bilaterally after 2 (n = 3) and 4 weeks (n = 3), perfusion fixed (80 mmHg, 15 min), and analyzed histologically. All grafts were patent at harvest, and flows distal to the grafted segments were not significantly different between grafts within an animal either at implant or subsequent harvest. Although CP arterial grafts still showed slight but significant dilation compared with native autograft, the dilation was much less than seen previously with either CP or native venous segments. No evidence of inflammation or IH was seen in CP arterial grafts. The absence of early IH or inflammation suggests that CP small diameter arteries may perform better than many currently available allograft tissues and synthetic prosthetics.

The temporal expression of transforming growth factor-beta 1 in early aortocoronary vein grafts

The success of coronary reconstructive procedures is limited by the high incidence of restenosis secondary to intimal hyperplasia (IH). Transforming growth factor-beta 1 (TGF-beta 1) is a growth factor which has been shown to be important in the early development of IH in arteries and peripheral vein grafts. To date, there is little information concerning the early remodeling in aortocoronary vein grafts (ACVG). The purpose of this study was to characterize the expression of TGF-beta 1 expression in early aortocoronary vein grafts. Eighteen mongrel dogs underwent aortocoronary vein bypass grafting. Vein grafts were excised at 2 hr, 4 hr, and 7 days after implantation, snap frozen, and processed for ribonuclease protection assays (RPA) using 32P-labeled riboprobes for TGF-beta 1 and 18 S rRNA. TGF-beta 1 expression was quantified by densitometric analysis of autoradiographs which were expressed as a ratio TGF-beta 1/rRNA. Representative vessel rings were also collected for histology. There was a significant rise in TGF-beta 1 expression in the 2-hr vein grafts (0.42 +/- 0.04 compared to control saphenous vein (0.21 +/- 0.05, P < 0.02). In addition, there was significant downregulation of TGF-beta 1 at 4 hr (0.28 +/- 0.05) and at 7 days (0.18 +/- 0.01) when compared to 2 hr (P < 0.05). Histological specimens showed minimal intimal hyperplasia at 7 days. These results show for the first time an acute rise in TGF-beta 1 expression in ACVG. This upregulation quickly subsides by 4 hr and gene expression approaches control values by 7 days. By understanding this temporal relationship of expression one could better target potential therapeutic modalities to attenuate IH.

Allopurinol improves myocardial reperfusion injury in a xanthine oxidase-free model

The ability of allopurinol to protect against reperfusion injury in the heart has usually been attributed to its xanthine oxidase (XO)-inhibiting properties. Human myocardium however, has exhibited low levels of XO activity. To investigate the effects of allopurinol in an XO-free model and determine whether pretreatment is necessary, 12 domestic pigs (15 kg to 20 kg) underwent occlusion of the left circumflex for 8 minutes followed by reperfusion for 4 hours. One group received allopurinol infusion (5 mg/kg IV) at occlusion over 45 minutes and a control group (n = 6) received a saline infusion (same volume). Left ventricular and aortic pressure, electrocardiograms, and regional wall motion (sonomicrometry) were monitored throughout the process. Regional blood flow (microspheres) were obtained before, during, and 5, 10, and 30 minutes after ischemia. Occlusion decreased transmural flow at the midpapillary level by 75% (0.28 versus 1.10 mL/minute/g). The allopurinol-treated group exhibited a mild, generalized hyperemia at 5 minutes (ischemic zone: 1.44 versus 1.10 mL/min/g, which returned to control levels at 10 and 30 minutes. In contrast, the control group was associated with only 80% restoration of resting blood flow at 5 minutes (0.84 versus 1.10 mL/min/g), which stabilized at 63% of control levels at 10 and 30 minutes. When evaluated for the propensity of arrhythmias using an arbitrary arrhythmia score, the allopurinol group demonstrated no myocardial ectopy when compared with the focal ectopy routinely encountered in the control group at all time intervals.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental supplemental vein grafting and hypoperfusion syndrome

An additional saphenous vein graft (SVG) sometimes is required to the same coronary system if acute internal thoracic artery (ITA) graft flow is inadequate. These experiments were conducted to determine the consequences produced by ITA-SVG dual grafting. Fourteen dogs each received two coronary grafts (without bypass, using local occlusion) to the proximal circumflex coronary artery, using the ITA and an SVG, and then the circumflex artery was ligated proximally. Simultaneous flow in both grafts was determined at rest and after pharmacologic (adenosine, phenylephrine) or physiologic (cardiac pacing) stimulation. Serial angiography was performed during the first 4 weeks after grafting to determine patency patterns of the ITAs and SVGs. In the resting heart, flow was 7.5 +/- 1.6 mL/min (17.5%) in the ITA graft and 35.3 +/- 5.2 mL/min (82.5%) in the SVG (mean +/- standard deviation [% total distal perfusion]), and the combined flow was not significantly different from the original native flow. Intravenous adenosine (0.2 mg.kg-1.min-1) preferentially increased both the total ITA flow and its fractional contribution to total distal perfusion (18.4 +/- 3.2 [31.1%]; p < 0.05 versus rest). Saphenous vein graft flow was not changed significantly (40.3 +/- 6.0 mL/min), in part due to a modest decrease in arterial pressure. In contrast, intravenous phenylephrine (0.003 mg.kg-1.min-1) decreased both absolute ITA flow and its relative contribution to distal perfusion (6.1 +/- 1.1 [10.9%]; p < 0.05 versus rest), despite an increased systemic perfusion pressure, which increased SVG flow significantly (50.1 +/- 4.8 [89.1%]; p < 0.05 versus rest).(ABSTRACT TRUNCATED AT 250 WORDS)

Distal flow determinants in canine myocardium perfused through internal thoracic artery bypass grafts

The dynamic reactivity and the acute, recruitable flow capacity of an internal thoracic artery (ITA) graft remains unclear. These experiments were conducted in 20 anesthetized dogs with the left ITA grafted to the circumflex artery, off pump, using a brief local occlusion. The left main coronary artery was occluded, rendering the entire left ventricle, including anterior descending artery and circumflex regions, totally dependent on the ITA graft. When the left main coronary artery was occluded, the ITA flow immediately increased more than fivefold (93.4 +/- 9.6 mL/min; mean +/- standard deviation), representing an absolute flow value three times higher than ITA flow measured in situ on the chest wall (27.5 +/- 9.6 mL/min; p < 0.05 versus control), and the ITA graft provided total resting flow requirements (93.4 +/- 9.6 mL/min) for both left anterior descending and circumflex coronary artery perfusion territories at levels comparable with measured native flow values (y = (0.9555)x + 21.9272; r = 0.976; p < 0.05). Pharmacologic challenge with adenosine (0.2 mg.kg-1.min-1 intravenously) significantly increased the graft flow (120.3 +/- 18.7 mL/min; p < 0.05 versus control), but also significantly decreased the mean arterial pressure (85.4 +/- 5.0 versus 74.6 +/- 6.1 mm Hg; p < 0.05). Phenylephrine (0.003 mg.kg-1.min-1 intravenously) significantly decreased ITA graft flow (81.2 +/- 9.0 mL/min; p < 0.05 versus control) despite significantly increased perfusion pressure (84.8 +/- 6.3 versus 108.2 +/- 8.6 mm Hg; p < 0.05 versus control).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac pacing induced flow responses in internal thoracic artery and saphenous vein coronary artery bypass grafts

The flow reactivity of an internal thoracic artery (ITA) graft and a vein graft for multiple coronary beds in response to different modes of cardiac pacing remains unclear. These experiments were conducted in 14 anesthetized dogs with the ITA or the vein grafted to the circumflex coronary artery, off pump, using a brief local occlusion. The left main coronary artery was occluded, rendering the entire left ventricle totally dependent upon the ITA graft or the vein graft. When the left main coronary artery was occluded and the heart rate was 120 beats per min, graft flow was 93.4 +/- 9.6 ml per min in the ITA, and 96.1 +/- 10.4 ml per min in the vein graft. Atrial pacing to increase heart rates 25% to 150 beats per min increased both the ITA graft flow (110.3 +/- 9.7 ml per min, p < 0.05 versus flow in sinus rhythm) and the vein graft flow (109.8 +/- 7.9 ml per min, p < 0.05 versus flow in sinus rhythm). The increases in flow in both cases were not attributable to changes in perfusion pressure. In contrast, ventricular pacing to the same heart rate decreased systemic pressure slightly, but insignificantly. Despite the slight decrease in perfusion pressure, ventricular pacing increased ITA flow (107.9 +/- 8.4 ml per min, p < 0.05 versus flow in sinus rhythm), but the increase in vein graft flow was not significant compared with flow in sinus rhythm (102.1 +/- 7.3 ml per min, p = ns versus flow in sinus rhythm).(ABSTRACT TRUNCATED AT 250 WORDS)

Bilateral vs single internal thoracic artery grafting for left main coronary artery occlusion

This study was conducted to compare the coronary flow distributed by single and bilateral internal thoracic artery (ITA) grafts in the setting of the left main coronary occlusion. Ten dogs underwent coronary artery bypass grafting through a left thoracotomy, off pump, using a brief local occlusion to perform the anastomosis. Dogs were randomly assigned to receive either a single left ITA (LITA) graft to the circumflex coronary artery (CFX), or bilateral ITA grafts, with additional placement of the right ITA (RITA) to the left anterior descending artery (LAD). After the grafts were placed, the left main coronary artery was ligated. Electromagnetic flows were obtained in the LAD and the CFX proximally and distally to ITA grafts in both groups before grafting and after grafting. ITA flow in situ was also measured before rotation from the chest wall. Total left ventricular flow requirements were satisfied equally well by either a single LITA graft (116.7 +/- 11.6 mL/min) or bilateral ITA grafts (total, 116.8 +/- 9.6 mL/min divided as LITA, 55.9 +/- 7.4 mL/min; RITA, 60.9 +/- 12.0 mL/min). When two grafts were replaced, competitive flow in the proximal regions of both native vessels was noted, although basal flow requirements were maintained. When an individual graft was occluded in the bilaterally grafted system, the remaining graft immediately recruited the additional flow, demonstrating that either right or left ITA can support flow demands five to six times higher than in situ chest wall flow (RITA, 21.9 +/- 3.1 mL/min; LITA, 22.3 +/- 4.9 mL/min). These data suggest that in this canine model, a single ITA graft can support the entire flow requirements of the left ventricle. Assuming no intervening stenosis is present in native coronary systems, bilateral ITA grafting may provide a margin of safety, but under resting conditions, provides no perfusion advantages over a single ITA graft.

Effect of chronic native flow competition on internal thoracic artery grafts

Residual competitive flow from the native coronary artery has been proposed as a mechanism that reduces flow in an internal thoracic artery graft (ITA), resulting in narrowing and ultimately failure of the graft. Results from acute experiments have indicated that competitive flow from a fully patent native artery did not abolish ITA graft flow. The present study was designed to examine the consequences of dynamic flow competition between the native vessel and the ITA graft in a chronic model. Fifteen mongrel dogs underwent coronary artery bypass grafting using the pedicled left ITA anastomosed to the normal, fully patent circumflex (CFX) coronary artery. The procedure was performed through a sterile thoracotomy, without systemic cardiopulmonary bypass, using a brief local occlusion to construct the anastomosis. Intraoperatively, ITA flow was measured in situ on the chest wall, before the pedicle was mobilized. Internal thoracic artery graft and distal CFX flow were measured after the anastomosis was completed, with and without brief occlusion of the proximal CFX. Angiography was performed 72 hours, 4 weeks, and 8 weeks later; graft patency and diameter were evaluated. After 8 weeks, open-chest direct flow measurements comparable with the intraoperative assessment were obtained. Two grafts (13%) occluded early, the technical result of poor anastomotic construction. In the 13 remaining animals, all grafts were widely patent at all time points. Internal thoracic artery flow in situ averaged 10.9 +/- 7.8 mL/min (mean +/- standard deviation), and was maintained after grafting (11.5 +/- 4.4 mL/min; p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Transsphenoidal microsurgical management of pituitary adenomas

The transsphenoidal microsurgical operation is the best choice for most pituitary adenomas, whether or not there is an extension into the sphenoid or a supra-sellar extension without lateral spread. The advantage of this approach is that it allows selective removal of the adenoma and therefore can preserve normal pituitary function. In our series of 249 cases 79% had achieved a remission at follow-up one year or more after surgery. The surgical failure rate was 21%, and the mortality rate 0.8%. Complications occurred in 5.6%; most were temporary and minimal. The recurrence rate after transsphenoidal microsurgery was lower than that quoted in the literature after craniotomy. The smaller the size of the adenomas and the less the hormone abnormality preoperatively, the better the outcome.

[A study of hygienic standard for titanium in the source of drinking water]

The smell and taste thresholds of titanium in water were tested. The results indicated that the concentration of smell and taste thresholds for Titanium were 4.329mg/L and 3.332mg/L respectively. The threshold below value of autopurification was 0.1mg/L. The toxicity assessment showed that the acute toxicity of titanium by oral route was of low order according to the toxicity classification. There was no obvious cumulative effect, nor was there mutagenesis demonstrable. Chronic toxicity test of titanium in rats showed that the maximum non-effective concentration was 1.08mg/L. It is suggested that the maximum allowable concentration of titanium in drinking water may be 0.1 mg/L.

Competitive flow from a fully patent coronary artery does not limit acute mammary graft flow

The shriveled, stenotic mammary graft sometimes observed after internal mammary artery (IMA) to coronary artery bypass grafting has been attributed to competitive flow from the insufficiently stenosed native coronary vessel. To study further the effects of native coronary artery competing flow on IMA graft flow, 10 dogs (mean weight, 23.5 +/- 3.69 kg) underwent coronary artery bypass grafting using the pedicled left IMA anastomosed to a normal, fully patent proximal circumflex (CFX) coronary artery. The procedure was performed through a left thoracotomy, off pump, using a brief local occlusion to perform the anastomosis. Native in situ IMA flow, CFX flow distal to the anastomosis, and IMA graft flow were measured using calibrated electromagnetic flow probes. When the CFX proximal to the anastomosis was occluded transiently, IMA flow increased to supply 100% of the previously measured distal CFX flow (60.2 +/- 7.9 mL/min). When both the IMA graft and CFX proximal to the anastomosis were patent, total distal perfusion was maintained (58.9 +/- 7.8 mL/min) and relative IMA graft flow (26.5 +/- 3.3 mL/min) was proportional to the relative diameter of the IMA graft to the native coronary artery (r = 0.96). The mean flow in the IMA in situ on the chest wall before its division was 23.8 +/- 8.1 mL/min. These results suggest that, at least acutely in a canine model, IMA graft flow is maintained above in situ levels even when grafted to a completely patent coronary artery and that acute competitive flow probably does not cause mammary artery shriveling.

Internal mammary artery use. Sternal revascularization and experimental infection patterns

We have described previously the acute sternal devascularization produced by mobilization of one or both internal mammary arteries (IMAs). The present experiments were conducted to examine the time course of sternal revascularization and infection patterns after IMA use. Twenty-four 8-week-old domestic pigs were obtained from a herd in which active Streptococcus faecalis had been detected in recent litters. After control blood flow procedures (microspheres) were completed, each pig underwent a median sternotomy; one or both IMAs were mobilized as a pedicle, and the sternotomy was repaired. Repeat blood flow determinations were made in half the pigs at 1 week and in the remainder after 2 weeks. The pigs were killed, the wound was examined, cultures were taken as indicated, and tissue was harvested for blood flow analysis. Despite the retention of an intact IMA on the contralateral side, persistent, significant sternal ischemia existed 2 weeks after repair. However, when both IMAs were used, the extent of devascularization was exaggerated, and revascularization was impaired further. Revascularization of intercostal muscle occurred more rapidly and was essentially returned to normal 2 weeks after sternotomy and IMA harvest. Active mediastinitis with erosion of the sternum was found in one (17%) of six pigs at 1 week and in four (67%) of six pigs at 2 weeks when the IMAs had been rotated bilaterally. No wound infections were detected in the single IMA resection group. These data suggest that bilateral IMA mobilization may delay an already slow revascularization process and predispose to infectious complications.

Feasibility of intraoperative aortic root angiography in the identification of critical coronary lesions

Early revascularization is critical for the treatment of acute myocardial infarction (AMI) because the ischemic myocardium begins to suffer irreversible damage after 4 h from the onset of symptoms. However, to make a diagnosis, perform coronary angiography, and prepare for operative revascularization usually takes longer than 4 h. Also, once a patient develops severe cardiogenic shock, coronary angiography is often impossible. Without angiography, the patient is no longer a candidate for surgical repair. To circumvent this problem, we designed this experiment to determine whether intraoperative aortic root angiography after cardiopulmonary bypass and cardioplegic arrest could satisfactorily substitute for angiographic examination in the identification of critical coronary lesions. The feasibility of this approach was tested in dog hearts in which one or tow of the major coronary arteries were ligated. The ascending aorta was then clamped, contrast material was injected, and continuous real-time fluoroscopic images were obtained and recorded on videotape. The videotape was then analyzed by three physicians independently, each without prior knowledge of the lesion locations. Lesions of the left anterior descending artery, the circumflex coronary artery, and the right coronary artery were identified with 94, 91, and 94% accuracy, respectively, for an overall identification rate of 92%. We conclude that aortic root angiography reliably demonstrates coronary artery lesions, and refinements in this technique may allow certain patients to undergo coronary operations without preoperative catheterization.

Improvement in thoracic aortic pressure after proximal aortic cross-clamping by balloon occlusion of the distal aorta

Spinal cord hypoperfusion injury is a devastating complication of cross-clamping the proximal thoracic aorta. The collateral circulation around the cross-clamp is generally poorly developed, and the run-off is immense, resulting in extremely low thoracic aortic and spinal cord perfusion pressures. The authors postulated that balloon occlusion of the abdominal aorta might confine this reduced collateral flow around the cross-clamp to the thoracic aorta. In 8 of 16 dogs subjected to aortic cross-clamping of the aorta just beyond the arch vessels, the abdominal aorta was also occluded by a balloon. Thoracic aortic pressure and spinal cord perfusion pressure were significantly higher in the animals with aortic balloon occlusion than in those without balloon occlusion (77 +/- 8 mm Hg versus 26 +/- 1 mm Hg, p less than 0.01, and 67 +/- 8 mm Hg versus 18 +/- 2 mm Hg, p less than 0.01, at 10 minutes after cross-clamping). Abdominal aortic balloon occlusion increases thoracic aortic pressure after the aorta is cross-clamped proximally. Further studies are necessary in primates to assess the effect of this procedure in spinal cord perfusion and the rate of paraplegia.

Reappraisal of the mechanism for cerebrospinal fluid hypertension during aortic surgery

Cerebrospinal fluid (CSF) hypertension during aortic surgery is a poorly understood, multifactorial event that may increase the risk of spinal cord injury. To assess the factors that may contribute to changes in CSF pressure during aortic surgery, measurements of ascending arterial and CSF pressures were made in 17 anesthetized mongrel dogs. Changes in CSF patterns were monitored under several conditions tested in random sequence. These included systemic hypertension produced by an infusion of phenylephrine, cross-clamping of the descending thoracic aorta, and manual, superior displacement of the transverse aortic arch (arch elevation), either alone or in conjunction with the cross-clamp. Hypertension, cross-clamping, and cross-clamping combined with arch elevation all produced significant increases in ascending mean arterial pressure (204 +/- 20, 170 +/- 8, and 158 +/- 11 mm Hg, respectively, vs. 117 +/- 8 mm Hg [control]; (p less than 0.01). Small, nonsignificant increases in CSF pressure were detected in the cross-clamp group, but none were detected with hypertension alone, despite significant increases in ascending arterial blood pressure in both groups. Thus, neither arterial hypertension nor cross-clamping alone could be demonstrated directly to cause significant CSF hypertension. However, when aortic elevation (displacement) was combined with cross-clamping, the rise in CSF pressure increased to significant levels, even though the ascending arterial hypertension was least severe in this group. In contrast, arch elevation alone did not produce any significant increase in ascending arterial pressure but did produce an approximately 114% increase in CSF pressure (15.2 +/- mm Hg vs. 7.7 +/- 1 mm Hg [control]; p less than 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)

Selective neurohormonal interactions in islet cell secretion in the isolated perfused human pancreas

To investigate the effects of stimulant interactions on alpha- and beta-cell secretions, the differential effects of gastric inhibitory polypeptide (GIP) and cholinergic stimulation (CS) on insulin (IRI) and glucagon (IRG) release were examined during euglycemic, single-pass perfusion in the isolated human pancreas. Pancreata obtained from 12 cadaver organ donors were perfused for 15-min test periods with (a) 1 nM GIP (b) intrinsic CS via bipolar electrical stimulation (10 V, 5 msec, 10 Hz) of the splanchnic neural fibers during simultaneous perfusion with 4 microM phentolamine and 6 microM propranolol, or (c) GIP and CS. The integrated response of IRI and IRG demonstrated that IRI release was stimulated 308 +/- 52 microU/g-min by GIP, 366 +/- 73 microU/g-min by CS, and 560 +/- 50 microU/g-min by GIP and CS (P less than 0.05). IRG release was stimulated 111 +/- 33 pg/g-min by GIP, 34 +/- 12 pg/g-min by CS, and 90 +/- 36 pg/g-min by GIP and CS. Combined hormonal and cholinergic stimulation was additive for IRI release, but not for IRG release. We conclude that the interaction of neural and hormonal islet cell stimuli is cell-type specific. This may result in selective impairment of hormone release after pancreatic denervation.