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Biomedical subjects

T H Young

Publications and source records attributed to T H Young.

36 records · Page 2Linked to original sources

Alcoholism and alcoholic organ damage and genetic polymorphisms of alcohol metabolizing enzymes in Chinese patients.

It is still not clear why some alcoholic patients acquire certain organ-specific complications of alcoholism whereas other alcoholic patients acquire different ones. As we know the liver alcohol dehydrogenase (ADH), aldehyde dehydrogenase (ALDH), and cytochrome P4502E1 (P4502E1) are polymorphic at the ADH2, ADH3, and ALDH2 loci and the 5'-flanking region of the P4502E1. The aim of this study was to investigate the differences between Chinese alcoholic patients with cirrhosis and acute pancreatitis by studying the genetic polymorphisms of ADH2, ADH3, ALDH2, and P4502E1. Genotyping of ADH2, ADH3, ALDH2, and P4502E1 was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods on peripheral white blood cell DNA from 75 alcoholic cirrhotic patients, 48 acute alcoholic pancreatitis patients, 19 heavy drinkers without liver disease or pancreatitis, and 235 controls. The results showed that the frequencies of the alleles ADH2*1 and ALDH2*1 in the alcoholic cirrhotic patients were significantly higher than those in the nonalcoholic controls. In acute alcoholic pancreatitis patients, only the frequency of allele ALDH2*1, not ADH2*1 was significantly higher than in the nonalcoholic controls. The allele frequency of ADH2*1 in acute pancreatitis patients was significantly lower (P < .01) than in alcoholic cirrhotic patients. The daily amount of alcohol consumption was significantly lower in patients with acute pancreatitis than in patients with cirrhosis (P < .0005). The genotype distributions of P4502E1, detected by RsaI and PstI, were not different among alcoholic cirrhotic patients, alcoholic pancreatitis patients, heavy drinker, and nonalcoholic controls. In conclusion, ALDH2*1 is the most important alcohol metabolizing gene affecting predisposition to alcoholism whereas the ADH2*2 gene may influence susceptibility to acute alcoholic pancreatitis. The patients with alcohol-induced cirrhosis and with alcohol-induced acute pancreatitis are of two different subpopulations.

Acute Disease↗

Detection of alphafetoprotein-expressing cells in the blood of patients with hepatoma and hepatitis.

The presence of tumour cells in the blood circulation may predict disease recurrence and metastasis. We have evaluated the specificity and sensitivity of detecting hepatoma cells in blood using nested polymerase chain reaction with primers specific for the alphafetoprotein (AFP) gene. The nested polymerase chain reaction amplified a 270-base pair AFP DNA fragment from cDNA of Hep 3B hepatoma cells. In a reconstitution experiment, AFP mRNA was detected from peripheral mononuclear cells isolated from 10 ml of blood containing as few as ten Hep 3B cells. Peripheral mononuclear cells from the blood of 20 hepatoma patients were analysed, and 19 patients showed positive AFP mRNA expression. Seven of 13 samples from hepatitis patients also showed positive AFP mRNA expression. All five paired samples of peripheral blood or umbilical cord blood from pregnant mothers and their babies, respectively, showed positive AFP expression. None of 22 control samples was positive. The presence of AFP mRNA in the blood of hepatitis or hepatoma patients suggests the presence of circulating hepatoma cells or hepatocytes in the circulation. The high incidence of AFP mRNA in the blood of hepatoma patients supports the notion of early haematogenous spreading of the disease.

Feasibility Studies↗

Evaluation of asymmetric poly(vinyl alcohol) membranes for use in artificial islets.

Islets of Langerhans surrounded by a semipermeable membrane to prevent the host immunosystem is a potential way to treat type I diabetes mellitus. In this study, a series of poly (vinyl alcohol) membranes were formed by adding polyethylene glycols to create pores in the skin layer. The permeability study showed the skin layer structure had an influence on the diffusion of low molecular weight glucose, vitamin B12 and insulin. The mass transfer coefficient was improved from 1.04 x 10(-4) to 2.16 x 10(-4) cm/ sec for glucose, from 2.84 x 10(-5) to 8.36 x 10(-5) cm/sec for vitamin B12 and from 1.45 x 10(-6) to 4.15 x 10(-6) cm/sec for insulin, whereas the passage of immunoglobulin G was completely prevented, indicating that these membranes could be effective in protecting islets from immunorejection. Thus such a membrane is an alternative potential material for artificial islets. In addition, we examined the insulin secretory response of islets separated by a poly(vinyl alcohol) membrane. We found that the insulin-secretion rate is relatively rapid compared to the permeation rate of insulin; thus, the process of the artificial islets is insulin-diffusion-controlled.

Biocompatible Materials↗

Soluble CD44 isoforms in serum as potential markers of metastatic gastric carcinoma.

A splice variant of CD44 (exon V4-V7) confers metastatic behavior in a rat carcinoma model; aberrant expression of splice variants has been detected on a variety of human tumor cell lines as well as primary and metastatic human tumors, including lymphomas, carcinomas (colon, thyroid, mamma, bladder), and glioma. We used enzyme-linked immunosorbent assay to determine the concentration of soluble CD44 in the serum samples of 10 normal individuals and 41 patients with various stages of gastric cancer. Soluble CD44S and its isoforms, V5 and V6, were present in the serum of normal individuals (288.53 +/- 18.33, 25.49 +/- 1.70, and 148.32 +/- 3.15 ng/ml, respectively). The concentrations of soluble CD44 V5 and V6 were elevated in patients with advanced gastric carcinoma (69.39 +/- 6.06 and 216.62 +/- 32.98 ng/ml, respectively). Serum CD44 V5 concentrations correlated with the extent of tumor invasion (T), the status of lymph node involvement (N), and distant metastasis (M) (TNM staging) (p < 0.05), whereas CD44S did not. These results suggest that detection of abnormal regulation of CD44 splicing could be helpful in gastric cancer diagnosis and disease evaluation.

Biomarkers, Tumor↗

A rare case of multiple intussusceptions: intense segmentary lipomatosis of the ileum.

We report a patient who presented with intestinal obstruction; his small intestine showed intense segmentary lipomatosis associated with unusually situated multiple intussusceptions. Preoperatively, we diagnosed intussusceptions in the ileocecal region by ultrasonography and computed tomographic scan. During surgery, the ileum was dilated and contained numerous movable polypoid masses. One reducible intussusception was encountered in the ileocecal region. In addition, an ileoileal intussusception that could not be reduced was resected with an end-to-end anastomosis. At histological examination, more than 150 submucosal lipomas were found.

Adult↗

Hydatid cysts in the liver.

A 67-year-old Taiwanese woman with multilocular hydatid cysts of the liver presented with a 5-month history of intermittent right upper abdominal discomfort. Abdominal ultrasonography and computed tomography showed multiple cysts in both lobes of the liver. Subsequent selective celiac angiography revealed an avascular space-occupying lesion in the right lobe. She underwent a radical excision of the cyst by total closed (without opening the wall) cystopericystectomy over segments 4, 5 and 6. Histologic study of the lesions showed three structural components: 1) an outer acellular laminated membrane, 2) a thin nucleated germinal membrane and 3) several protoscolices with Echinococcus granulosus suckers. The patient has been well for 5 years since her discharge. Although hydatid cysts of the liver are extremely rare in Taiwan, they may cause life-threatening complications and mortality. Making a preoperative diagnosis is important and is only possible if this rare disease is kept in mind.

Aged↗

The accuracy of the rapid urease test and 13C-urea breath test in the diagnosis of Helicobacter pylori infection.

BACKGROUND: Helicobacter pylori (H. pylori) is an important predisposing factor in peptic ulcer disease. Many tests have been proposed, but there is no generally accepted single method for the detection of H. pylori. This study compared the four available methods in the detection of H. pylori. METHODS: One hundred and thirteen patients were studied with endoscopic biopsy. Biopsy specimens were examined with modified Giemsa stain and rapid urease (CLO) test. Serology (ELISA) and 13C-urea breath test (13C-UBT) were also performed. The 13C-UBT results were expressed at an excess delta 13CO2 excretion of 5 per mil as the upper limit. Multiple breath samples were collected 15, 30 and 60 minutes following 13C-urea ingestion (t = 15, 30, 60) in the first 60 patients. Gastric inflammatory changes were graded according to the Whitehead classification. The diagnostic gold standard was defined when three or more of the four test parameters showed positive. RESULTS: According to this diagnostic gold standard, the positive rates of H. pylori were 97.9% for duodenal ulcer, 81.8% for gastric ulcer, 47.6% for symptomatic gastritis and 13.6% for asymptomatics. Rapid urease test and the 13C-UBT had better sensitivity (93.6% and 96.2%) and accuracy (93.8% and 93.8%). The specificity and positive predictive value for rapid urease test was better than 13C-UBT (94.3% v.s. 88.6%, 97.3% v.s. 94.9% respectively). Modified Giemsa stain had the lowest sensitivity (87.2%), and the ELISA test had the lowest specificity (71.4%). Severity of the gastric inflammatory processes was directly correlated with the excess delta 13CO2 (r = 0.576). CONCLUSIONS: Both the CLO and 13C-UBT had higher accuracy in the detection of H. pylori. When the CLO test result is positive, there is little additional diagnostic benefit from performing other tests. If patients refuse endoscopic examination, 13C-UBT is a good alternative for the detection of H. pylori, either during diagnosis or follow-up after therapy.

Adult↗

An investigation of whether polymorphisms of cytochrome P4502E1 are genetic markers of susceptibility to alcoholic end-stage organ damage in a Chinese population.

The human cytochrome P4502E1 gene (P4502E1), coding for an ethanol-inducible nitrosamine-metabolizing P-450, is involved in the metabolism of ethanol and many known carcinogens. Recently, restriction fragment length polymorphisms (RFLPs) within the P4502E1 have been suggested as genetic markers of susceptibility to alcohol-induced liver disease but the previous studies disagree whether alcoholics with c1 or c2 allele are more susceptible to alcohol-induced liver diseases. Using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, we determined the RsaI and PstI polymorphism of P4502E1 in 77 Chinese alcoholic patients (54 with alcohol-induced cirrhosis and 23 with acute alcohol-induced pancreatitis) and 164 non-alcoholics and compared them with previously published data. The PCR-RFLPs showed three P4502E1 genotypes: type A, homozygote c1/c1; type B, heterozygote c1/c2; and type C, homozygote c2/c2. The RsaI and PstI polymorphism of P4502E1 were completely linked in both Chinese alcoholics and nonalcoholic controls. The rare allele (c2) occurs at similar frequency of 0.232 and 0.234 (P > .05) in nonalcoholic controls and alcoholics, respectively. The genotype distributions of P4502E1 between Chinese alcoholics and nonalcoholics are not significantly different. The genotype and allele frequencies of P4502E1 for Chinese are significantly different from those of Swedes, European-Americans, and African-Americans, respectively (P < .00001), but very similar to Japanese (P > .05). In conclusion, ethnic variations exist between Asians and Caucasians and between Asians and African-Americans. No allelic variants at loci associated with RsaI/PstI RFLPs result in phenotypes displaying greater susceptibility to alcohol-induced cirrhosis or alcoholism in Chinese populations, which contradicts previous reports from Japanese groups.

Adult↗

Captopril-induced agranulocytosis: a case report.

Captopril 12.5 mg twice daily was initially administered given to a woman with chronic renal failure and hypertension. Three weeks later, she developed chills, high fever and sore throat. Hemogram showed severe neutropenia; the white cell count showed 600/cu mm; bone marrow aspirate and biopsy revealed a paucity of myeloid series. Antineutrophil antibody was not detected in the serum. The neutrophil counts returned to normal after captopril was discontinued two weeks later. We recommend that the peripheral white blood cell count in patients whom captopril is prescribed must be carefully monitored in the first three months, particularly in those with impaired renal function.

Aged↗

Cystic lymphangioma of the transverse colon: report of a case and review of the literature.

A 32-year-old Chinese man with cystic lymphangioma of the transverse colon is described. He presented with a 1-year history of altered bowel habits. Double-contrast barium enema study demonstrated a submucosal lesion in the midportion of the transverse colon with intact mucosa. Computed tomography (CT) showed a round 3.0-cm submucosal cystic mass lesion. Colonoscopy revealed a smooth, soft polypoid mass on a broad base. He underwent segmental resection of the colon. Histologically, the lesion was characterized by cystic lymphangioma originating from the submucosa. The clinical features, radiology, appropriate treatment, and possible pathogenesis of colonic lymphangioma are discussed.

Adult↗

The effect of morphology variety of EVAL membranes on the behavior of myoblasts in vitro.

Not only the surface morphology but also the surface chemistry can be changed during the fabrication of biomaterials. Therefore, the result of a biocompatibility test of one material may alter to a great extent, dependent on the fabrication process. In this paper, the in vitro interaction of myoblasts and EVAL membranes with different surface properties was investigated. It was observed that moderate contact angle and porous structure are favourable for the cell adhesion and growth. However, cell adhesion and growth were decreased on a porous structure with particulate morphology and higher contact angle.

Animals↗