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Biomedical subjects

W S Tsai

Publications and source records attributed to W S Tsai.

At least 19 recordsLinked to original sources

Prospective study comparing wounds closed with tape with sutured wounds in colorectal surgery.

HYPOTHESIS: To test the efficacy of adhesive paper tape in the closure of clean-contaminated wounds following elective colorectal resection. DESIGN: A prospective, nonrandomized controlled study. SETTING: A medical center that offers a mixture of primary, secondary, and tertiary care services. PATIENTS: The group undergoing skin closure with paper tape (PT group) consisted of 150 patients. The group undergoing skin closure with interrupted suture (IS group) also comprised 150 patients. All 300 patients underwent elective colorectal resection in 1997. MAIN OUTCOME MEASURES: The duration of skin closure, wound complication rate, and cosmetic appearance of the scar at 6 months after operation were compared using the chi(2)test or t test. RESULTS: The mean +/- SD average duration of skin closure was 116 +/- 23 seconds for the PT group and 457 +/- 64 seconds for the IS group (P<.01). The wound complication rate was 3.3% (3 cases with wound infection; 2 with wound separation) for the PT group and 3.3% (5 cases with wound infection) for the IS group (P = 1.0). No significant differences were found between the narrowest width (mean +/- SD, 2.2 +/- 0.9 mm vs 2.3 +/- 1.0 mm) and widest width (mean +/- SD, 4.7 +/- 2.0 mm vs 4.3 +/- 1.8 mm) of scar formation between the 2 groups at 6 months after the operation. Ninety-eight percent of patients in the PT group reported satisfaction with their scar, compared with 92% in the IS group (P =.03). CONCLUSION: Compared with the traditional suture method, paper tape closure in the treatment of clean-contaminated wounds was less time consuming and produced greater patient satisfaction with no increased rate of wound complications.

Adhesives↗

Cortisol suppresses prolactin release through a non-genomic mechanism involving interactions with the plasma membrane.

In the classical theory of steroid hormone action, steroids diffuse through the membrane and alter transcription of specific genes resulting in synthesis of proteins important for modulating cell function. Most often, steroids work solely through the genome to exert their physiological actions in a process that normally takes hours or days to occur. In tilapia (Oreochromis mossambicus), cortisol inhibits prolactin (PRL) release within 10-20 min in vitro. This action is accompanied by similarly rapid reductions in cellular Ca(2+) and cAMP levels, second messengers known to transduce the membrane effects of peptide hormones. We further examined whether cortisol might inhibit PRL release through a non-genomic, membrane-associated mechanism using the protein synthesis inhibitor, cycloheximide, and a membrane impermeant form of cortisol, cortisol-21 hemisuccinate BSA (HEF/BSA). Cycloheximide (2 and 10 microg/ml) was ineffective in overcoming PRL release induced by hyposmotic medium or that inhibited by cortisol over 4 h static incubations. These dosages reduced protein synthesis as measured by amino acid incorporation in pituitaries by 75 and 99%, respectively. During 4-h incubation, HEF/BSA and HEF significantly reduced PRL release in a dose-dependent fashion. These studies suggest that cortisol inhibits PRL release through a plasma membrane-associated, protein-synthesis independent (non-genomic) pathway.

Animals↗

Renal malformations in children with Turner's syndrome.

Between 1988 and 1999, renal sonography and intravenous urography were performed to detect renal malformations in 54 patients with Turner's syndrome (TS). The mean age of these patients at diagnosis of TS was 9.2 +/- 4.6 years. Renal malformations were detected in 21 patients by intravenous urography and there was no significant difference in the frequency of renal malformations among different karyotype groups. Horseshoe kidney was the most common renal malformation, followed by duplex kidney. Fifteen of 21 renal malformations were not detected by renal sonography. We conclude that these TS patients had a high frequency of renal malformations, and that the detection rate of horseshoe kidney and duplex kidney by renal sonography was not satisfactory. Although renal sonography alone can be used to detect more severe renal malformations that may need further management, it may underestimate the frequency of renal malformation in children with TS.

Adolescent↗

Inhibitory effects of n-3 polyunsaturated fatty acids on sigmoid colon cancer transformants.

Various types of polyunsaturated fatty acids (PUFAs) have been suggested to exert different effects on the colon in terms of promotion or inhibition of tumor development. Results of in vitro and in vivo studies are, however, inconsistent and it remains unclear whether or not the cellular effects of PUFAs change along with the malignant transformation of colonic cells. In this study, we used the NIH3T3 cell line and its SIC (sigmoid colon cancer) oncogene transformants to compare the effects of PUFAs on the proliferation of non-malignant and malignant cells. We also determined the cellular utilization of fatty acids in media by a high-performance liquid chromatography method. The addition of exogenous arachidonic acid (ARA, an n-6 fatty acid), eicosapentaenoic acid (EPA, n-3), and docosahexaenoic acid (DHA, n-3) exerted different effects on NIH3T3 cells, and on SIC transformants, in which selective inhibitory effects were observed at media concentrations ranging from 10 to 20 microg/ml. In cells cultured in media supplemented with EPA or DHA at a concentration of 2 microg/ml, which had no effect on cell proliferation, the cellular utilization of linoleic acid (n-6), a precursor of n-3 fatty acids, was inhibited. This inhibition was stronger in SIC transformants than in NIH3T3 cells (P < 0.05). There was no difference in the utilization of fatty acids between the two cell lines cultured in media supplemented with ARA. We conclude that the cellular response to exogenous long-chain PUFAs is modified during the course of malignant transformation, and that EPA and DHA (n-3 PUFAs) appear to have specific inhibitory effects on cancer cells and may thus enhance the host defense against colon cancer.

Animals↗

Diagnosis and management of stenotic aorto-arteriopathy in childhood.

Stenotic aorto-arteriopathy is an uncommon vascular lesion characterized by segmental arterial stenoses. We reviewed the experience with several management algorithms to define the most effective management course. The clinical records of 14 pediatric patients with acquired SAA who presented over a 16-year period were reviewed. Most patients presented with a mid-thoracoabdominal coarctation and were diagnosed with Takayasu arteritis. Differentiating between Takayasu arteritis and fibromuscular dysplasia was difficult on clinical grounds or by angiography. Medical management of the end-organ disease and renovascular hypertension was only palliative. Selective percutaneous transluminal balloon angioplasty of the stenotic renal arteries had only transient benefits; renal autotransplantation had slightly better success. Dilation of stenosed aortic segments with balloon-expandable endovascular stents and subsequent renal autotransplantation proved useful. Distinguishing SAA resulting from fibromuscular dysplasia caused by Takayasu arteritis in the chronic vaso-occlusive phase may be unnecessary for effective treatment. Therapy should focus on interventions to minimize the end-organ damage caused by the vaso-occlusive manifestations of the disorders.

Adolescent↗

Role of thermography in the diagnosis of undescended testes.

OBJECTIVES: The location of an undescended testis is important for the choice of therapy. Ultrasonography cannot serve as a stand-alone screening method in the management of the undescended testis because of its limited sensitivity and accuracy. The aim of this study was to clarify the diagnostic value of thermography in the patients with undescended testes. METHODS: We evaluated prospectively 28 patients with 36 undescended testes from January 1995 to December 1996. The patients' ages ranged from 16 to 39 months with a mean age of 26.3 +/- 8.2 months. In addition to physical palpation by a pediatric surgeon, ultrasonography and thermography were performed for screening the locations of retained testes. RESULTS: The diagnostic rates were 63.9% (23/36) by palpation, 65.7% (23/35) by ultrasonography and 54.5% (18/33) by thermography. The results of the three diagnostic methods showed no significant difference by Fisher's exact test. Of the 17 higher located testes (inguinal canal and above external ring) 7 were palpable, 8 were identified by ultrasonography, 10 were detected by thermography. Of the 7 nonpalpable testes and testes not detected by ultrasonography, 5, including 2 intra-abdominal testes, were identified by thermography. CONCLUSION: It is suggested that thermography can play a role in locating high undescended testes which are nonpalpable and not detected by ultrasonography.

Child, Preschool↗

Urinary endothelin-1 in children with acute renal failure of tubular origin.

To understand the changes of urinary endothelin-1 (ET-1) concentrations in acute renal failure (ARF) and to investigate the origin of human urinary ET-1, we studied urinary ET-1 excretion in 70 normal children and 12 children with ARF caused by tubular dysfunction. Urinary ET-1 excretion was expressed as a ratio of urinary ET-1 to urinary creatinine (ET-1/Cr). Among healthy children, the highest urinary ET-1/Cr values were found during infancy. In patients with ARF, there was a positive correlation between urinary ET-1/Cr values and daily total urinary ET-1 (r = 0.42, n = 26, p < 0.05). Plasma ET-1 concentrations were elevated in children with ARF during the period of peak serum creatinine concentration. During the course of ARF, the lowest urinary ET-1/Cr value occurred during the period of peak serum creatinine, whereas the plasma ET-1 concentration declined after the peak. These results provide insight into the developmental changes of urinary ET-1 values in normal children, and illustrate the pattern of changes in plasma and urinary ET-1 concentrations during the course of ARF in children. The results suggest that renal production, rather than clearance from the circulation by glomerular filtration, may be the source of urinary ET-1.

Acute Kidney Injury↗

Differential effects of polyunsaturated fatty acids on chemosensitivity of NIH3T3 cells and its transformants.

Polyunsaturated fatty acids (PUFAs) have been suggested, on the basis of animal-model studies, to be related not only to cancer development but also to chemotherapeutic effects. Controversy persists, however, as to which types of PUFAs are beneficial in terms of chemosensitivity. In this study, we used the NIH3T3 cell line and its SIC(sigmoid colon cancer)-oncogene transformants to investigate the effects of PUFAs on the chemosensitivity of non-malignant and malignant cells in terms of cell proliferation. We also determined the fatty-acid composition of cells by high-performance liquid chromatography (HPLC). The results revealed that the sensitivity of SIC transformants to mitomycin C (MC) was lower than that of NIH3T3 cells cultured in 10% calf-serum DMEM without PUFA supplementation. When cells were cultured in DMEM supplemented with eicosapentaenoic acid (EPA) at a concentration (2 micrograms/ml) that does not influence cell proliferation, the sensitivity of SIC transformants to MC increased, whereas that of NIH3T3 cells decreased in comparison with the sensitivity of cells cultured without PUFA supplementation (p < 0.05). There was no difference between the 2 cell lines in the chemosensitivity of cells cultured in medium supplemented with arachidonic acid (ARA). The SIC transformants contained more stearic acid (C:18) and less lauric acid (C:12) than NIH3T3 cells cultured without PUFA. Culturing the cells in medium supplemented with EPA or ARA modified the cellular fatty-acid composition. EPA caused the relative combined percentage of lauric acid and myristic acid (C:14) in SIC transformants to decrease significantly, and the SIC transformants tended to accumulate additional EPA, in contrast to the NIH3T3 cells. We conclude that the alterations in fatty-acid composition in malignant transformants caused by exogenous EPA differ from those in non-malignant cells, and that these changes account for the increased chemosensitivity of malignant transformants. Although preliminary, these findings imply that EPA specifically enhances the chemosensitivity of malignant cells.

3T3 Cells↗

Ornithine transcarbamylase deficiency.

Two infants, one male and one female, with elevated serum ammonia levels, were shown, based on urine organic acid analysis and DNA studies, to have ornithine transcarbamylase (OTC) deficiency. OTC deficiency is one of the most common urea cycle disorders. Hyperammonemia occurred at 3 days of age in the male infant, and at approximately 7 days of age in the female infant. Administration of sodium benzoate and sodium phenylacetate lowered the serum ammonia level effectively in both cases. Other modalities, including peritoneal dialysis and protein restriction, were also important in the control of the serum ammonia level. The mother of the male infant was shown to be a carrier of the OTC gene mutation by allopurinol loading test. The mutation site of the OTC gene for the female infant was identified, but her mother did not have the mutation. OTC deficiency, an incompletely dominant X-linked disorder, is a severe disease even for females and prompt treatment and precise genetic counseling are mandatory.

Female↗

Tricho-rhino-phalangeal syndrome type II associated with epiglottic aplasia and congenital nephrotic syndrome.

A male neonate with tricho-rhino-phalangeal syndrome type II (Langer-Giedion syndrome) and interstitial deletion of chromosome 8 with karyotype 46, XY, del (8) (q24.11-->q24.13) is reported. In addition to hypotrichosis of the scalp hair, abnormally bulbous nose and redundant skin, which are usually found in this syndrome, aplasia of the epiglottis and non-Finnish type congenital nephrotic syndrome were also present. He died of renal failure and respiratory failure at 11 days of age. Electron microscopy of renal necropsy showed foot process loss, focal thickening and splitting of the glomerular basement membrane and mesangial expansion. These have never been reported and could be new associations in this disease that may serve to support the concept of contiguous gene syndrome in patients with tricho-rhino-phalangeal syndrome.

Epiglottis↗

Use of restriction endonuclease analysis of plasmids and pulsed-field gel electrophoresis to investigate outbreaks of methicillin-resistant Staphylococcus aureus infection.

We used restriction endonuclease analysis of plasmids (REAP) and pulsed-field gel electrophoresis (PFGE) to investigate clusterings of methicillin-resistant Staphylococcus aureus (MRSA) infections in our orthopedic unit, neurosurgery unit, intensive care unit, and burn unit. Fourteen different strain types were identified by REAP and 10 different strain types were identified by PFGE among 25 MRSA isolates collected during these incidents of infection. Though neither technique was clearly superior to the other for typing MRSA isolates, REAP is recommended as a relatively simple and reproducible technique for the preliminary investigation of MRSA infection outbreaks in clinical settings.

Bacterial Typing Techniques↗

Epidemiological typing of Flavimonas oryzihabitans by PCR and pulsed-field gel electrophoresis.

Flavimonas oryzihabitans has emerged as a potential nosocomial pathogen in recent years. The typing method for characterization of this species has never been reported before. Pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-based PCR were used to generate DNA fingerprints for 14F. oryzihabitans isolates obtained from eight episodes of nosocomial infections during a 2-year period. Both techniques successfully classified these clinical isolates into eight distinct genotypes, thus indicating that all of these episodes of infections were independent. In contrast, repeated isolates from the same patient were assigned to identical genotypes. The reproducibility of both techniques was good. Therefore, we conclude that both PFGE and ERIC-PCR have comparable reproducible and discriminatory powers for the typing of F. oryzihabitans and may be useful for clarifying the epidemiology of this species; however, ERIC-PCR has the advantages of both speed and simplicity.

Bacterial Typing Techniques↗

Urinary N-acetyl-beta-D-glucosaminidase activity in children with insulin-dependent diabetes mellitus.

Urinary N-acetyl-beta-D-glucosaminidase (NAG) is a sensitive indicator of renal tubular injury. The aim of the study is to determine the status of urinary NAG excretion in Chinese children with insulin-dependent diabetes mellitus (IDDM) but without any clinical evidence of nephropathy, and to try to find the possible associated factors of such tubular injury if any. Thirty-one children (8 males and 23 females) with IDDM who have normal serum creatinine, 24-hour urinary creatinine clearance and urinary total protein excretion were enrolled in the study. The mean age of the patients was 11.6 +/- 3.7 years. The random urinary NAG levels of the patients and the normal controls were 10.76 +/- 6.32 and 3.65 +/- 1.84 U/g Cr, respectively (p < 0.001). The diabetic patients were divided into 4 groups according to their duration of disease ( < 3, 3-5, 5-10 and 10-16 years). The random urinary NAG level of each group was significantly higher than that of the control group, but there was no statistically significant difference among any 2 of these 4 groups. No good correlation was noted in our study between urinary NAG and patients' age (r = -0.23, p = 0.21), serum cholesterol (r = 0.04, p = 0.84), insulin dosage (r = 0.13, p = 0.49), 24 hour urinary creatinine clearance (r= -0.41, p - 0.085) or urinary total protein excretion (r = -0.28, p = 0.26). However, the plasma HbAlc level correlated significantly with urinary NAG (r = 0.50, p < 0.01). We concluded that urinary NAG is increased in Chinese IDDM children without any clinical evidence of nephropathy. Such increased excretion is correlated with the plasma HbAlc level. Our results suggests that there is tubular dysfunction in the early stage of IDDM children even before there is any clinical evidence of nephropathy, and urinary NAG may reflect glycemic control in such patients.

Acetylglucosaminidase↗

DNA fingerprinting of Pseudomonas aeruginosa serotype O11 by enterobacterial repetitive intergenic consensus-polymerase chain reaction and pulsed-field gel electrophoresis.

We report the use of pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-based polymerase chain reaction (PCR) to characterize clinical isolates of Pseudomonas aeruginosa serotype O11 collected from an incident of hospital-acquired infection. Both typing techniques differentiated 20 different strain types among seven epidemiologically related isolates and 22 epidemiologically unrelated isolates. There was complete concordance between these two techniques. Our results indicate that the ERIC-based PCR technique represents a rapid and simple means for typing P. aeruginosa serotype O11 with a level of discrimination equivalent to that of PFGE.

Base Sequence↗

Comparison of susceptibility to extended-spectrum beta-lactam antibiotics and ciprofloxacin among gram-negative bacilli isolated from intensive care units.

The in vitro activities of extended-spectrum beta-lactam antibiotics (including piperacillin, cefotaxime, ceftriaxone, ceftazidime, cefepime, imipenem, and meropenems) were assessed and compared with the activity of ciprofloxacin against 366 clinical Gram-negative bacilli isolates from the intensive care units of Taichung Veterans General Hospital. The most prevalent species isolated were Pseudomonas aeruginosa and Acinetobacter baumannii. The activities of ceftazidime, cefepime, imipenem, and meropenem against these isolates were comparable to that of ciprofloxacin. Meropenem was found to be the most potent extended-spectrum beta-lactam antibiotic tested and the MIC50s and MIC90s for most of these multiresistant strains were lower than those of imipenem, ceftazidime, and cefepime, except for Stenotrophomonas maltophilia. The extended-spectrum beta-lactam antibiotics that were still active against S. maltophilia were piperacillin and ceftazidime. More than 50% of Enterobacter spp. were resistant to third-generation cephalosporins and piperacillin, but they remained susceptible to carbapenems and cefepime.

Anti-Bacterial Agents↗

Comparison of different PCR approaches for characterization of Burkholderia (Pseudomonas) cepacia isolates.

In this study, we evaluated three PCR methods for epidemiological typing of Burkholderia (Pseudomonas) cepacia--PCR-ribotyping, arbitrarily primed PCR (AP-PCR) and enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR)--and compared them with pulsed-field gel electrophoresis. The analysis was performed with 31 isolates of B. cepacia, comprising 23 epidemiologically unrelated isolates and 8 isolates collected from the same patient during two episodes of bacteremia. Pulsed-field gel electrophoresis, ERIC-PCR, and AP-PCR identified 23 distinct types among the 23 unrelated isolates, while PCR-ribotyping only identified 12 strain types, even after AluI digestion of the amplification products. Among the eight isolates collected from the same patient, all typing techniques revealed two clones of strains. The day-to-day reproducibilities of PCR-ribotyping and ERIC-PCR were good, while greater day-to-day variations were noted in the fingerprints obtained by AP-PCR. We conclude that all three PCR techniques are useful for rapid epidemiological typing of B. cepacia, but ERIC-PCR seems to be more reproducible and discriminative.

Base Sequence↗