Search PubMed⌕ Search

Biomedical subjects

A Tan

Publications and source records attributed to A Tan.

134 records · Page 8Linked to original sources
PubMedDate not supplied

Properties of aminopeptidase activity involved in the conversion of vasopressin by rat brain membranes.

Previously it has been shown that vasopressin (VP) and oxytocin are converted by aminopeptidase activity in brain membranes into fragments with potent CNS activities. This report concerns the properties of this enzyme activity, addressed as VP-converting aminopeptidase (VP-AP) activity, in membranes of the rat brain. The VP-AP activity had a pH optimum at pH 7.0 and had a Km of 17 microM for its action on VP. Amastatin was the most potent aminopeptidase inhibitor. Enzyme activity was inhibited by relatively low concentrations of metal chelators. Treatment of brain membranes by EDTA resulted in loss of enzyme activity that was completely reversed by 10 microM Zn2+, indicating that VP-AP activity is a metallopeptidase. Several VP analogues and fragments, in particular VP(1-8), inhibited the action of enzyme activity on VP. Among peptides unrelated to VP, angiotension I, somatostatin, and porcine ACTH(1-39) markedly inhibited enzyme activity. Solubilization of VP-AP activity from brain membranes and gel filtration on Sephadex G200 showed two peaks of activity, one eluting with an apparent mass of about 140 kDa, the other in the void volume. Gel filtration fractions were able to convert [3H][Phe3]VP in a step-wise fashion. The VP-AP-like activity was found in many tissues outside the brain. Highest activity was present in lung, kidney, parts of the gastrointestinal tract, ovary, and uterus. The results indicate that VP-AP activity is a widely distributed enzyme with probably multiple functions, one of which involves the metabolism of vasopressin in the brain.

Aminopeptidases↗
PubMedDate not supplied

Macrophagelike vacuolated renal tubular cells in the urine of a male with osmotic nephrosis associated with intravenous immunoglobulin therapy. A case report.

BACKGROUND: Osmotic nephrosis is a form of renal tubular injury that has been found in patients treated with intravenous immunoglobulin (IVIG). CASE: A 46-year-old male who had two courses of chemotherapy for acute myelogenous leukemia was found to have refractory thrombocytopenia. After IVIG (Sandoglobulin 12%, Novartis) administration (1 g/kg) for five consecutive days, the patient became oliguric and eventually anuric on the fifth dose. Hemodialysis was initiated, and urine production was noted on day 2 of hospitalization. Routine cytologic examination of fresh, voided urine showed numerous macrophagelike, bland epithelial cells with abundant, multivacuolated cytoplasm. Cytokeratin immunostain revealed positivity, thus confirming the epithelial origin of these cells. CONCLUSION: To our knowledge, this is the first such case reported in the English-language cytology literature. Awareness of a patient's clinical history may be helpful in avoiding an incorrect diagnosis. Urine cytology may be useful in obtaining an early diagnosis of osmotic nephrosis in patients receiving high-dose IVIG therapy that may eliminate the need for a renal biopsy.

Acute Kidney Injury↗
PubMedDate not supplied

Stages of change for physical activity, diet, and smoking among HMO members with chronic conditions.

PURPOSE: This paper investigated whether stage of change for health behaviors was associated with the presence of chronic conditions. DESIGN: A stratified cross-sectional survey by mail with telephone follow-up. SETTINGS: This study was conducted at a mixed-model HMO with 650,000 members based in Minnesota. SUBJECTS: The sample consisted of a random sample of 8000 HMO members age 40 or over with systematic oversampling of members with hypertension, diabetes, dyslipidemia, or heart disease. MEASURES: In addition to demographics, readiness to change for physical activity, fat intake, fruit and vegetable intake, and smoking were assessed. RESULTS: The adjusted response rate was 82.4%. In a logistic regression analysis, members with one or more than one chronic condition had greater readiness to change for three out of four risk factors compared to members with no chronic conditions. CONCLUSIONS: The stage-of-change distribution of HMO members with chronic conditions suggests that members at highest risk of adverse health outcomes have the greatest readiness to change behavioral risk factors. Based on these observations, targeted, stage-specific efforts to support behavior change are likely to be both acceptable and effective in HMO members with chronic conditions. Improving stage of change for behavioral risk factors for members with diabetes may present special problems and opportunities.

Adult↗
PubMedDate not supplied

The results of surgical treatment and percutaneous drainage of hepatic hydatid disease.

BACKGROUND: Hydatid disease of the liver remains an important and challenging problem in rural areas. Although, surgery is considered the treatment of choice for hydatid disease of the liver, percutaneous drainage is an alternative treatment method for selected cases. The purpose of this study was to evaluate the results of percutaneous drainage and surgery. METHODS: A total of 66 patients underwent surgery; 36 cases had percutaneous drainage and were evaluated preoperatively for treatment choice according to localization, multiplicity, echographic type and size of the cysts in the liver. The patients were also evaluated postoperatively for systemic complications, e.g. fistula formation, infection of residual cyst, recurrence and hospitalization period for each group. RESULTS: Two groups, those with multiple cysts and cysts bigger than 5 cm, were treated by surgery. At the end of two treatment modalities, systemic complications, biliary fistulizations, recurrence and infection of cyst's cavity were seen more frequently in the surgery group and caused a longer hospital stay. CONCLUSIONS: Percutaneous drainage plus medical treatment can be successfully done for type I, type II and some selected type III hydatid cysts of the liver giving less complications, lower recurrence and shorter hospitalization periods. But, surgery is the primary treatment for big, multiple, complicated and recurrent hydatid cysts of the liver.

Adult↗
PubMedDate not supplied

Hypoganglionic megacolon associated Chiliaditi's syndrome treated by subtotal colectomy: a case report.

In 1910, Chiliaditi described hepatodiaphragmatic interposition of the colon (Chiliaditi's syndrome). The condition is easily recognised on an antero-posterial chest radiograph. The interposed segment of bowel is usually the hepatic flexure of the colon. The degree of interposition varies from simple wedging to complete occupation of the right subdiaphragmatic space. The management is usually conservative and surgical intervention is rarely indicated. We present a patient with hepatodiaphragmatic interposition of the colon, associated with megacolon, requiring subtotal colectomy and ileosigmoid anastomosis for severe chronic constipation.

Adult↗
PubMedDate not supplied

Surgical treatment of rectal prolapse. A retrospective analysis of 94 cases.

METHODS: A retrospective analysis evaluating 94 patients who underwent posterior rectopexy in 48 patients (51%), resection with or without rectopexy in 19 patients (20%) and Delorme's procedure in 27 patients (29%) was carried out for rectal prolapse in the last 15 years. The surgical procedures are described in detail. Postoperative evaluation was possible in all patients and mean observation time was 3.2 years. RESULTS: Mortality rate was zero. Recurrence was seen in 4 cases (4.2%), only after Delorme's procedures. The proportion of continent patients increased from 69.2% preoperatively to 91.6% postoperatively. Defecation difficulties and incomplete evacuation did not change beneficially after the surgery. Important postoperative complications, retrograde ejaculation and impotence were seen in 5 male patients (17.2) after posterior rectopexy, and were a major cause of dissatisfaction. CONCLUSIONS: In conclusion, Delorme's procedure, posterior rectopexy and resection procedures are effective surgical operations for treatment of rectal prolapse but extensive pelvic dissection during the posterior rectopexy may create serious sexual problems in male patients.

Adult↗