Polycaprolactone/Chitosan Composite Nanofiber Membrane as a Preferred Scaffold for the Culture of Mesothelial Cells and the Repair of Damaged Mesothelium.

Mesothelial cells are specific epithelial cells lining the serosal cavity and internal organs. Nonetheless, few studies have explored the possibility to culture mesothelial cells in a nanostructure scaffold for tissue engineering applications. Therefore, this study aims to fabricate nanofibers from a polycaprolactone (PCL) and PCL/chitosan (CS) blend by electrospinning, and to elucidate the effect of CS on the cellular response of mesothelial cells. The results demonstrate that a PCL and PCL/CS nanofiber membrane scaffold could be prepared with a comparable fiber diameter (~300 nm) and porosity for cell culture. Blending CS with PCL influenced the mechanical properties of the scaffold due to interference of PCL crystallinity in the nanofibers. However, CS substantially improves scaffold hydrophilicity and results in a ~6-times-higher cell attachment rate in PCL/CS. The mesothelial cells maintain high viability in both nanofiber membranes, but PCL/CS provides better maintenance of cobblestone-like mesothelial morphology. From gene expression analysis and immunofluorescence staining, the incorporation of CS also results in the upregulated expression of mesothelial marker genes and the enhanced production of key mesothelial maker proteins, endorsing PCL/CS to better maintain the mesothelial phenotype. The PCL/CS scaffold was therefore chosen for the in vivo studies, which involved transplanting a cell/scaffold construct containing allograft mesothelial cells for mesothelium reconstruction in rats. In the absence of mesothelial cells, the mesothelium wound covered with PCL/CS showed an inflammatory response. In contrast, a mesothelium layer similar to native mesothelium tissue could be obtained by implanting the cell/scaffold construct, based on hematoxylin and eosin (H&E) and immunohistochemical staining.

Medical Humanities Education and Its Influence on Students' Outcomes in Taiwan: A Systematic Review.

Background: Medical education has emphasized the importance of integrating medical humanities training into the curriculum to benefit medical and nursing students' future practice, featuring in the list of national funding priorities for healthcare education research in Taiwan for many years. However, the extent to which this drive has resulted in medical humanities training, what rationales underpin its inclusion, and its efficacy is largely unknown. This study aims to address these issues across medical humanities programs within the Taiwanese context. Methods: We conducted a systematic review. Inclusion criteria included studies in English or Mandarin reporting outcomes of medical humanities courses in healthcare education settings in Taiwan between 2000 and 2019. We searched across five electronic databases (PubMed, Embase, ERIC, PsycInfo, Web of Science), following PRISMA guidelines. The Best Evidence Medical Education (BEME) Global Scale and Kirkpatrick Levels are used for identifying the strength of evidence. Results: 17 articles were extracted from the 134 identified. Intrinsic and instrumental rationales for the inclusion of medical humanities education were common, compared with epistemological-based and critical-based approaches. Several positive impacts were identified in relation to participation including modification of attitudes, knowledge, and skills. However, the highest level (i.e., unequivocal) of evidence characterized by effects on students' behaviors or ongoing interaction with colleagues and patients is lacking. Conclusion: Findings suggest that although medical humanities education is widely implemented in Taiwan, no clear consensus has been reached regarding the rationale for inclusion or how it is localized from Western to Asian contexts. Future research still needs to explore the long-term impact of medical humanities education for medical and nursing students and its impact on patient care. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO, identifier: CRD42019123967.

Academic outcome and moderator of flipped classroom learning program "Teaching on the Run".

BACKGROUND: Flipped classroom (FC) style Australian faculty development program Teaching on the Run (TOTR) was introduced into Chang Gung Memorial Hospital since 2014. However, its effectiveness in Taiwan has not been formally assessed. This work intended to examine the learning gain of TOTR and identify the moderators of FC outcome by using TOTR as a representative model of FC. METHODS: A non-controlled before-after study was undertaken by retrospective analysis of learning data collected during TOTR workshop. Multiple choice questions were tested at baseline (pre-test), after pre-class learning (mid-test) and after classroom activity (post-test) to assess the learning gain. All available demographic and learning variables were included in the moderator analysis. RESULTS: Stepwise and significant improvement in exam scores was noted from pre-test to mid-test and post-test (p < 0.001 for both). Univariate analysis showed pre-test scores, mid-test scores, class participation and session of TOTR were significantly associated with post-test scores. However, multivariate analysis by general linear model showed only mid-test scores and session of TOTR were significant predictor of post-test score. Generalized estimating equations analysis showed that class participation is a significant moderator that influence the scores change from mid-test to post-test. CONCLUSION: TOTR is effective in improving knowledge of teaching skills for clinical teachers in Taiwan. Achievement in pre-class learning, class participation and learner factor are potential moderators of the FC outcome. Thus, facilitators should try their best to promote a good achievement in pre-class learning and engagement in classroom activity in FC style learning.

Effective Preventive Strategies to Prevent Secondary Transmission of COVID-19 in Hemodialysis Unit: The First Month of Community Outbreak in Taiwan.

BACKGROUND: Dialyzed patients are vulnerable to coronavirus infection disease 2019 (COVID-19). The incidence and outcome of COVID-19 in hemodialysis (HD) patients in Taiwan remain unclear. A series of preventive measures were executed to combat COVID-19 transmission among HD patients. METHODS: We carried out a series of forward-looking and practical preventive strategies of COVID-19 control in our HD center. Incidences of COVID-19 of our HD unit were compared with those of national and local estimates from a community outbreak from 15 May to 30 June 2021. Prognostic factors associated with mortality were analyzed. RESULTS: The national incidence of COVID-19 was 0.062%; being highest in Taipei City (0.173%), followed by New Taipei City (0.161%) and Keelung (0.083%). The overall incidence in Keelung HD patients was 0.666%. One patient of our HD center contracted COVID-19 from the household; however, we have contained secondary transmission in our HD center by implementing strict preventive measures. The mortality rate of HD patients in Keelung was 66.6%. The median Ct value of HD patients was 17.53 (11.75-27.90) upon diagnosis. The deceased patients had a higher cardiac/thoracic ratio than alive (0.61 vs. 0.55, p = 0.036). CONCLUSIONS: Taking aggressive and proactive infection preventive measures impedes the secondary transmission of COVID-19 in HD facilities. COVID-19-associated mortality was high in HD patients, being the high cardiac-thoracic ratio, an important prognostic factor for clinical outcome of infected HD patients.

Prognostic Value of C-Reactive Protein-to-Albumin Ratio in Head and Neck Cancer: A Meta-Analysis.

The C-reactive protein-to-albumin ratio is a proven prognostic predictor of nasopharyngeal carcinoma. However, the role of the C-reactive protein-to-albumin ratio in other head and neck cancers remains unclear. This meta-analysis explored the prognostic value of the C-reactive protein-to-albumin ratio in head and neck cancers. A systematic search was conducted. Outcomes of interest included overall survival, disease-free survival, and distant metastasis-free survival. The hazard ratio with 95% confidence interval was pooled using a random-effects model. A total of 11 publications from the literature were included, allowing for the analysis of 7080 participants. Data pooling demonstrated that pretreatment C-reactive protein-to-albumin ratio had a hazard ratio of 1.88 (95% CI: 1.49-2.37, p < 0.001) for predicting overall survival, 1.91 (95% CI: 1.18-3.08, p = 0.002) for disease-free survival, and 1.46 (95% CI: 1.08-1.96, p = 0.001) for distant metastasis-free survival. Subgroup analysis showed that the C-reactive protein-to-albumin ratio is a significant prognostic marker for various head and neck cancers. An elevated pretreatment C-reactive protein-to-albumin ratio predicts a worse prognosis for patients with head and neck cancers. Therefore, the C-reactive protein-to-albumin ratio could serve as a potential prognostic biomarker facilitating treatment stratification.

Preparation of Gelatin and Gelatin/Hyaluronic Acid Cryogel Scaffolds for the 3D Culture of Mesothelial Cells and Mesothelium Tissue Regeneration.

Mesothelial cells are specific epithelial cells that are lined in the serosal cavity and internal organs. Nonetheless, few studies have explored the possibility to culture mesothelial cells in a three-dimensional (3D) scaffold for tissue engineering applications. Towards this end, we fabricated macroporous scaffolds from gelatin and gelatin/hyaluronic acid (HA) by cryogelation, and elucidated the influence of HA on cryogel properties and the cellular phenotype of mesothelial cells cultured within the 3D scaffolds. The incorporation of HA was found not to significantly change the pore size, porosity, water uptake kinetics, and swelling ratios of the cryogel scaffolds, but led to a faster scaffold degradation in the collagenase solution. Adding 5% HA in the composite cryogels also decreased the ultimate compressive stress (strain) and toughness of the scaffold, but enhanced the elastic modulus. From the in vitro cell culture, rat mesothelial cells showed quantitative cell viability in gelatin (G) and gelatin/HA (GH) cryogels. Nonetheless, mesothelial cells cultured in GH cryogels showed a change in the cell morphology and cytoskeleton arrangement, reduced cell proliferation rate, and downregulation of the mesothelium specific maker gene expression. The production of key mesothelium proteins E-cadherin and calretinin were also reduced in the GH cryogels. Choosing the best G cryogels for in vivo studies, the cell/cryogel construct was used for the transplantation of allograft mesothelial cells for mesothelium reconstruction in rats. A mesothelium layer similar to the native mesothelium tissue could be obtained 21 days post-implantation, based on hematoxylin and eosin (H&E) and immunohistochemical staining.

Age-Related Macular Degeneration in Chronic Kidney Disease: A Meta-Analysis of Observational Studies.

BACKGROUND: Age-related macular degeneration (AMD) is an important cause of blindness in aged people. Chronic kidney disease (CKD) was reported to be associated with a higher risk of AMD. However, supporting evidence was inconsistent between studies. This work intends to examine whether a positive association exists between CKD and AMD by systematic review and meta-analysis. METHODS: A systematic search of electronic databases (Medline, PubMed, Cochrane and EMBASE) and reference lists on June 2017. The key inclusion criteria were controlled trials that investigated the relationship between AMD and CKD. The outcome measures included risk ratios and/or occurrence rates of AMD in CKD vs. non-CKD population. Data were pooled according to the type of AMD by random effect model. RESULTS: Twelve observational studies (3 cohorts, 2 case controls, and 7 cross-sectionals) with a total 335,601 participants were included. Eleven studies reported risk ratios and 9 reported occurrence rates. Pooled prevalence for early, advanced, and any AMD were all higher in the CKD population than in the non-CKD population. The pooled multivariate adjusted OR of CKD vs. non-CKD was 1.49 (95% CI 1.11-2.02) for early, 1.55 (95% CI 1.05-2.27) for exudative, 1.58 (95% CI 1.12-2.23) for advanced, and 1.35 (95% CI 1.05-1.73) for any AMD. However, high statistical heterogeneity and methodological diversity existed. Moreover, results were inconsistent between different study designs. CONCLUSIONS: The overall results support a positive association between CKD and AMD, although some limitations exist. Given the risk that AMD is increased in CKD, regular eye screenings for the CKD population is recommended for an early detection and intervention.

Academic outcomes of flipped classroom learning: a meta-analysis.

CONTEXT: The flipped classroom (FC), reversing lecture and homework elements of a course, is popular in medical education. The FC uses technology-enhanced pre-class learning to transmit knowledge, incorporating in-class interaction to enhance higher cognitive learning. However, the FC model is expensive and research on its effectiveness remains inconclusive. The aim of this study was to compare the efficacy of the FC model over traditional lecture-based (LB) learning by meta-analysis. METHODS: We systematically searched MEDLINE, PubMed, ERIC, CINAHL, EMBASE, reference lists and Association for Medical Education in Europe (AMEE) conference books. Controlled trials comparing academic outcomes between the FC and LB approaches in higher education were considered eligible. The main findings were pooled using a random-effects model when appropriate. RESULTS: Forty-six studies (9026 participants) were included, comprising four randomised controlled trials (RCTs), 19 quasi-experimental studies and 23 cohort studies. Study populations were health science (n = 32) and non health science (n = 14) students. The risk of bias was high (36/37 articles). Meta-analyses revealed that the FC had significantly better outcomes than the LB method in examination scores (post-intervention and pre-post change) and course grades, but not in objective structured clinical examination scores. Subgroup analyses showed the advantage of the FC was not observed in RCTs, non-USA countries, nursing and other health science disciplines and earlier publication years (2013 and 2014). Cumulative analysis and meta-regression suggested a tendency for progressively better outcomes by year. Outcome assessments rarely focused on behaviour change. CONCLUSIONS: The FC method is associated with greater academic achievement than the LB approach for higher-level learning outcomes, which has become more obvious in recent years. However, results should be interpreted with caution because of the high methodological diversity, statistical heterogeneity and risk of bias in the studies used. Future studies should have high methodological rigour, a standardised FC format and utilise assessment tools evaluating higher cognitive learning and behaviour change to further examine differences between FC and LB learning.

Amplification of HER2 and TOP2A and deletion of TOP2A genes in a series of Taiwanese breast cancer.

BACKGROUND: The prognostic relevance of topoisomerase II alpha (TOP2A) copy number change remains not well established. This study is aimed to investigate the frequency and pattern of TOP2A aberrations; to correlate TOP2A alterations with human epidermal growth factor receptor 2 (HER2) status and clinicopathological parameters, and further to explore prognostic value of TOP2A and HER2 status in breast cancer in Taiwan. METHODS: We analyzed tissue samples from 311 invasive carcinomas in tissue microarrays for TOP2A and HER2 status by fluorescent in situ hybridization. RESULTS: TOP2A copy number change is an infrequent genetic event (9.8% amplification and 2.7% deletion) and is present in both HER2-amplified and nonamplified tumors. TOP2A amplification is statistically associated with age >50 at diagnosis (P = 0.016) and HER2 amplification (P < 0.001). HER2 amplification, but not TOP2A amplification, is a predictor of unfavorable prognosis (P = 0.002). Univariate and multivariate analysis showed that higher histologic grading, positive nodal involvement, and HER2 positivity were associated with poorer overall survival. Cytogenetically, double minutes-type amplification is the predominant pattern for both genes (HER2: 64% and TOP2A: 93.1%). Homogeneous staining region-type signals of both genes are resistant to RNase digestion, supporting that these were not nuclear accumulation of mRNA transcripts. CONCLUSION: Our results demonstrate the prognostic value of tumor grading, nodal involvement, and HER2 status in Taiwanese breast cancer. TOP2A aberrations are an infrequent event independent of HER2 status, and TOP2A amplification carries no prognostic value. The predictive value of TOP2A aberrations in patients of breast cancer taking athracycline-containing treatment in Taiwan remains to be determined in prospectively well-designed clinical trials.

Utilization of Signal-to-Cutoff Ratio of Hepatitis C Virus Antibody Assay in Predicting HCV Viremia among Hemodialysis Patients.

BACKGROUND: Hepatitis C virus (HCV) infection is a common cause of acute and chronic hepatitis among the hemodialysis population. To prevent cross infection between hemodialysis patients during the hemodialysis procedure, routine screening of anti-HCV antibody is recommended. However, a reactive anti-HCV EIA test is not equal to active HCV infection. An expensive RT-PCR study is required to confirm HCV viremia. This will significantly increase the cost burden because payment for each hemodialysis treatment is very low in Taiwan. Thus, it is useful to identify parameters that could predict HCV viremia among anti-HCV-reactive patients. In this study, we examined the usefulness of signal-to-cut (S/CO) ratio of anti-HCV antibody in discriminating HCV viremia from non-viremia among the anti-HCV-reactive hemodialysis population. MATERIALS AND METHODS: In a cross-sectional measurement of anti-HCV antibody among 369 chronic hemodialysis patients, 44 showed reactive and 9 grey zone reaction for anti-HCV. These 53 patients underwent further blood tests for the measurement of AST, ALT and HCV RNA (by RT-PCR). The results of RT-PCR were used as a dependent variable. Then, S/CO ratios of anti-HCV, serum AST, ALT levels, age and duration of hemodialysis were used as independent variables to undergo ROC curve and logistic regression analysis. RESULTS: Thirty-six of the 53 reactive and grey zone patients were positive for HCV RNA in the RT-PCR study. Patients who were positive for HCV RNA had a higher S/CO ratio (p < 0.01), higher AST and ALT levels (p < 0.01), and longer duration on hemodialysis (p < 0.05) than those negative for HCV RNA. Logistic regression revealed that only S/CO ratio was a significant predictor for HCV viremia (p = 0.004). ROC curve analysis showed that S/CO ratio had a highest area under curve (0.967, p < 0.001), followed by ALT (0.826, p < 0.001), AST (0.778, p = 0.001), duration on hemodialysis (0.606, p = 0.215) and age (0.426, p = 0.386) in discriminating HCV viremia from non-viremia. Using a cutoff S/CO ratio of 65, we can confirm HCV viremia with a diagnostic specificity of 100%, sensitivity of 80.1% and positive predictive value of 100%. CONCLUSION: S/CO ratio is a useful indicator in predicting HCV viremia among anti-HCV-reactive hemodialysis patients. Patients with an S/CO ratio >65 can be regarded as those with active HCV infection. Alternatively, patients with reactive anti-HCV but with an S/CO ratio <65 should receive further RT-PCR test.

Absence of estrogen receptor alpha (ESR1) gene amplification in a series of breast cancers in Taiwan.

Immunohistochemical expression of ERα, encoded by the ESR1 (estrogen receptor 1) gene located at 6q25.1, is the most important determinant of responsiveness to endocrine therapy in breast cancer. The prevalence and significance of ESR1 amplification in breast cancer remain controversial. We set out to assess ESR1 status and its relevance in breast cancer in Taiwan. We tested tissue samples from 311 invasive carcinomas in a tissue microarray for ESR1 status by fluorescent in situ hybridization (FISH) and chromogenic in situ hybridization (CISH). In order to examine its association with ERα and ESR1 status, HER2 status was determined by FISH. Of the carcinomas, 58.8 % (183/311) was ERα positive. None of the carcinomas showed amplification of ESR1 by either method, whereas 24.1 % (75/311) of the carcinomas harbored HER2 amplification. Of the carcinomas, 9.6 % (26/301) showed ESR1 gain (1.3 ≤ ratio ESR1/chromosome 6 < 2) by FISH and 10 % (24/299) by CISH. FISH and CISH results showed a good correlation (κ-coefficient = 0.786). ESR1 gain by FISH and CISH was significantly associated with high-grade (P = 0.0294 and 0.0417, respectively) but not with ERα expression, HER2 status, or overall survival. ERα positivity was significantly associated with better overall survival (P = 0.039). HER2 amplification was significantly related with poor overall survival (P = 0.002). Our data confirm that in breast cancer, HER2 amplification is a frequent genetic aberration and a negative prognostic factor, and show that ESR1 amplification is not a key genetic abnormality in the tumorigenesis of breast cancer in Taiwan.

Experience in primary culture of human peritoneal mesothelial cell.

To compare the growth condition between different sources and different culture environments, mesothelial cells were isolated from omentum and peritoneal dialysate effluent (PDE), seeded at different densities (5 × 105, 1 × 105, 5 × 104, 1 × 104, 5 × 10³, 1 × 10³ and 5 × 10² cells/cm², respectively), supported with different fetal calf serum (FCS) concentrations (3%, 6%, 10% and 15%) and grown in dishes with and without gelatin pre-coating. Growth condition was evaluated by simple morphological observation. Cells phenotype was examined by immunofluorescent staining. The results showed that omentum-derived mesothelial cells generally showed a uniform growth pattern with good quality. Alternatively, there was a wide patient-to-patient variation in PDE-derived culture. Heterogeneous colonies composed of a mixture of large, small or abortive mesothelial colonies as well as fibroblastoid colonies were frequently observed. A minimum seeding density of 5 × 10³ cells/cm² is required for the omentum-derived mesothelial cells to grow to confluent monolayer (1-5 × 104 cells/cm² for initial culture from fresh PDE). Appropriate seeding density is always associated with successful culture in omentumbased culture, but not in PDE-based culture. Mesothelial cells could grow to confluency regardless of FCS concentration and gelatin pre-coating. However, growth rate was slower in lower FCS concentrations and on dishes without gelatin coating. Most cells in culture expressed cytokeratin and vimentin, but not VWF. Alpha-smooth muscle actin frequently appeared in cytokeratin+ mesothelial cells, especially in higher FCS concentrations and in PDE-derived culture. Our data demonstrate that PDE, in contrast to omentum, provides a source of mesothelial cells with poor and unstable quality for primary culture. Healthy cell quality and sufficient seeding density seem to be the most important factors for successful culture of mesothelial cells. The frequent occurrence of epithelial-to-mesenchymal transition in cultured mesothelial cells indicates the feasibility of mesothelial cells to undergo phenotype change upon environment changes, especially following chronic exposure to uremic environment and dialysate in peritoneal dialysis patients.

Potential role of bone marrow-derived cells in the turnover of mesothelium.

BACKGROUND: Bone marrow cell has been proposed as a source of new mesothelium, but supporting evidence is rare. This study examines the validity of this hypothesis by using green fluorescent protein (GFP) and Y-chromosome trackers to identify the presence of donor marrow cells in peritoneal membrane of bone marrow transplant recipient mice. METHODS: Cross-gender and GFP-mismatched bone marrow transplantation was undertaken in 20 FVB mice. Five recipients were killed 2, 4, and 6 weeks and 6 months later. Peritoneal tissues were obtained for the detection of GFP and Y chromosome by immunohistochemical staining (IHC) and chromogenic in situ hybridization (CISH). RESULTS: GFP+ cells could be found in the peritoneal membrane of bone marrow transplant recipients. However, the level of engraftment was low, accounting for 0.9%, 0.8%, 0.7%, and 2.2% of the total counted mesothelial cells in intestinal serosa at 2, 4, and 6 weeks and 6 months post-transplantation, respectively. The presence of donor marrow cells within mesothelium was again confirmed by the detection of Y-chromosome-containing cells. Moreover, Y-chromosome+ cells incorporated within the mesothelium were positively stained by anticytokeratin antibody. CONCLUSIONS: Donor marrow cells could attach to mesothelium and exhibit mesothelial marker cytokeratin in bone marrow transplant recipients. This finding suggests that bone marrow-derived cells might participate in the turnover of mesothelium.

Prospective randomized study for comparison of open surgery with laparoscopic-assisted placement of Tenckhoff peritoneal dialysis catheter--a single center experience and literature review.

BACKGROUND: The ideal method for catheter placement in patients undergoing peritoneal dialysis remains debatable. This prospective study intends to clarify whether laparoscopic assisted percutaneous puncture is superior to open surgery. MATERIALS AND METHODS: From 2002 to 2006, 77 patients receiving first catheter placement were enrolled and randomized to either an open group of 40 patients or a laparoscopic group of 37 patients. Patient characteristics, operation-related data, procedural complications, and clinical outcome were compared by using the statistical software SPSS ver. 11.5 (SPSS, Chicago, IL). RESULTS: Laparoscopy had a longer operative time (68.32+/-31.90 versus 46.68+/-15.99 min; P<0.001), shorter wound length (1.69+/-0.46 versus 2.34+/-0.84 cm; P<0.001), and higher costs (P<0.001) compared with open surgery. Laparoscopy tended to have a higher incidence of pericannular bleeding (21.6% versus 7.5%) and a lower rate of early catheter migration (2.7% versus 15.0%), but its early/late/overall complication rate did not statistically differ. No surgical mortality occurred. Rate and cause of overall mortality or catheter dropout did not statistically differ. Catheter longevity was equivalent in both groups. CONCLUSIONS: Laparoscopic assisted percutaneous puncture exhibited no superiority to open surgery. As a matter of fact, open surgery's shorter operative time and reduced equipment requirement can increase cost-effectiveness. Therefore, conventional open surgery is recommended for most patients with primary catheter placement.

Concurrent hepatic and ruptured renal angiomyolipoma in tuberous sclerosis complex.

Angiomyolipoma of the liver or kidney is one of the clinical manifestations of tuberous sclerosis complex. However, concurrence of angiomyolipoma in both liver and kidney associated with tuberous sclerosis complex is a rare entity. Renal angiomyolipomas with large aneurysms confer a higher probability of rupture as compared to small aneurysms. Herein, we document a case of tuberous sclerosis coexisting with hepatic and renal angiomyolipoma in a 37 year-old woman who presented with an acute abdomen due to ruptured tumor. Computed tomography of the abdomen revealed multiple tumors over the bilateral kidneys and liver. A right nephrectomy was performed. During surgery, a liver biopsy was performed from which a preliminary diagnosis of necrosis was established. However, immunoreactivity staining using monoclonal antibody HMB-45 (Human Melanoma, Black) led to the final diagnosis of angiomyolipoma. We emphasized that pathologists and clinicians should be aware that cases of tuberous sclerosis complex may be associated with renal and hepatic angiomyolipoma. To avoid an inappropriate diagnosis, before diagnosing liver necrosis, immunohistochemical staining for HMB-45 is recommended.

An outbreak of methicillin-resistant Staphylococcus aureus infections related to central venous catheters for hemodialysis.

OBJECTIVES: To determine risk factors for hemodialysis catheter-related bloodstream infections (HCRBSIs) and investigate whether use of maximal sterile barrier precautions would prevent HCRBSIs. SETTING: Tertiary-care medical center hemodialysis unit. DESIGN: Open trial with historical comparison and case-control study of risk factors for HCRBSIs. METHODS: Prospective surveillance was used to compare HCRBSI rates for 1 year before and after implementation of maximal sterile barrier precautions. A case-control study compared 50 case-patients with HCRBSI with 51 randomly selected control-patients. RESULTS: The HCRBSI rate was 1.6% per 100 dialysis runs (CI95, 1.1%-2.3%) in the first year and 0.77% (CI95, 0.5%-1.1%) in the second year (P = .0106). The most frequent cause of HCRBSI was MRSA in the first year (15 of 32) and MSSA in the second year (13 of 18). Ten MRSA blood isolates in the first year were identical by PFGE. Diabetes mellitus was a risk factor for HCRBSI. Age, gender, site of hemodialysis central venous catheter (CVC), other underlying diseases, coma score, APACHE II score, serum albumin level, and cholesterol level were not associated with HCRBSI and did not change between the 2 years. Hospital stay was prolonged for case-patients (32.78 +/- 20.96 days) versus control-patients (22.75 +/- 17.33 days), but mortality did not differ. CONCLUSIONS: Use of maximal sterile barrier precautions during the insertion of CVCs reduced HCRBSIs in dialysis patients and seemed cost-effective. Diabetes mellitus was associated with HCRBSI. An outbreak of MRSA in the first year was likely caused by cross-infection via medical personnel.

Upper urinary tract tumor in a duplicated collecting system: report of three cases and review of the literature.

Despite the common anomaly of a duplicated collecting system in the urinary tract, urothelial cancer in a duplicated collecting system is a rare occurrence. Herein, we present 2 cases of renal pelvis tumor and 1 case of a ureter tumor which coexisted with a duplicated collecting system. One of the renal pelvis tumors developed bilateral transitional cell carcinoma within the bilateral duplicated pelvis. This has not been reported previously. The tumor of the ureter in the latter case was located at the junction site of the bifurcation. This finding is consistent with the postulation that urine reflux chronically irritates the distal segment of a duplicated ureter, rendering this segment susceptible to malignant change. Recurrence of the tumor is frequently observed, which necessitates an early diagnosis and radical treatment.

Repeated gallium-67 scan demonstrating an occult mycotic aneurysm of the aortic arch due to Salmonella.

A 71 y-old female with 40 degrees C fever and a change in consciousness during haemodialysis was referred for a gallium-67 scan, which revealed a horseshoe-like radioactive accumulation in the mediastinal region. Salmonella enteritidis was isolated from blood culture. Magnetic resonance imaging confirmed an aortic arch aneurysm. The patient died without surgery.

Coexistence of autosomal dominant polycystic kidney disease and neurofibromatosis: report of a family.

Autosomal dominant polycystic kidney disease (ADPKD) and neurofibromatosis are both autosomal dominant heredofamilial disorders. Concurrence of these two diseases is very rare. Herein, we report the coexistence of neurofibromatosis in 3 members, a mother and her 2 sons, of a family with preexisting ADPKD. The chromosomal studies of these patients show no translocation, deletion, or other gross abnormality. It is possible that a mutated neurofibromatosis gene developed in the ADPKD mother with subsequent inherence of both ADPKD and NF genes in her 2 sons.