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Biomedical subjects

H Lee

Publications and source records attributed to H Lee.

At least 685 records · Page 38Linked to original sources
PubMed1991

Immunologic correlates of spontaneous lymphocyte proliferation in human T-lymphotropic virus infection.

Previously we showed that mononuclear cells from about half of human T-lymphotropic virus (HTLV)-seropositive persons exhibit spontaneous proliferation in vitro. We sought to determine if proliferation was associated with other immunologic changes characteristic of HTLV infection. The parameters assessed were (1) percentages of lymphocytes expressing CD4 and/or CD25 (interleukin-2 receptor), (2) serum levels of soluble CD25, (3) serostatus for other viruses, (4) anti-HTLV antibody levels, and (5) HTLV type determined by polymerase chain reaction or serologic reactivity with type-specific peptides. The proliferation+ HTLV (PROL+) group, proliferation HTLV (PROL-) group, and control group showed similar percentages of CD4+, CD25+, and CD4+CD25+ lymphocytes; serum levels of soluble CD25 were also similar. Antibodies to cytomegalovirus, hepatitis B core, and hepatitis C were present in similar proportions of PROL+ and PROL+ groups. However, a significant association was found between spontaneous proliferation and anti-HTLV antibody levels; sera from 67% of PROL+ persons, but only 18% of PROL- persons, required dilution to yield absorbance values within the linear range of the anti-HTLV antibody assay. In the PROL+ group, persons whose sera required the most dilution had proliferative responses significantly higher than those whose sera required no dilution. The PROL+ and PROL groups were similar with regard to the relative distribution of HTLV-I and HTLV-II infection. These findings indicate that HTLV-related spontaneous lymphocyte proliferation is related to levels of circulating anti-HTLV antibodies, and characterizes both HTLV-I and HTLV-II infection.

Antibodies, Viral↗
PubMed1991

The effects of glucocorticoid hormone on the expression of c-jun.

The effects of glucocorticoid hormone on the expression of c-jun in the fibroblasts were studied. The expression of c-jun was repressed by dexamethasone in the NIH3T3 cells, but not in the transformed B104-1 or EJ-Ras cells. The repression was not relieved by the addition of cycloheximide.

Animals↗
PubMed1991

Role of intraoperative enteroscopy in obscure gastrointestinal bleeding of small bowel origin.

Intraoperative enteroscopy was performed in 12 patients (median age 68 years) with obscure gastrointestinal bleeding probably of small bowel origin, six of whom were men. All the patients were evaluated by routine haematological, coagulation and biochemical profiles, upper and lower gastrointestinal endoscopies, visceral angiography and/or isotope scanning. All the patients were anaemic. Visceral angiography was useful on three of the 12 occasions on which it was used and isotope scanning was valuable on eight of the 11 occasions it was used. Nine patients had undergone previous laparotomy. Enteroscopy was performed successfully in all cases, with fresh blood and discrete vascular lesions being the chief findings (10 of 12 cases). Segmental resections (n = 8) and local resections (n = 2) were performed in ten patients, with two patients having more than one laparotomy for rebleeding. Five patients developed postoperative complications and there was an operative death and one late death. Three of the ten surviving patients experienced further rebleeding. Intraoperative enteroscopy is now an essential adjunct to laparotomy for gastrointestinal bleeding which has been localized to the small bowel before operation.

Aged↗
PubMed1991

Endogenous protein substrates for prostatic acid phosphatase in human prostate.

In order to identify the endogenous phosphoprotein substrates for human prostatic acid phosphatase (PAP), cellular proteins of human normal, benign, and malignant prostatic tissues as well as carcinoma cell lines were phosphorylated by the cellular kinases in the presence of (gamma-32P)-ATP and then were subjected to dephosphorylation reaction by PAP. Of several endogenous phosphoproteins, PAP preferentially dephosphorylated a cytosolic protein of Mr 83 kDa. The dephosphorylation of the 83 kDa phosphoprotein (designated pp83) by PAP was uniformly observed in all cells/tissues of prostate origin, and was completely inhibited by L(+)-tartrate, the classic inhibitor of PAP. Phosphoamino acid analysis revealed that pp83 was a tyrosine-poor phosphoprotein and was mostly dephosphorylated by PAP at serine/threonine residues rather than tyrosine residues. Further comparison of dephosphorylation rate with that of an endogenous phosphotyrosine-containing phosphoprotein (pp53) revealed that PAP possessed both phosphoserine/threonine protein phosphatase and phosphotyrosine protein phosphatase activity. These results demonstrate that pp83 apparently is an endogenous substrate of PAP in human prostate, and that, instead of a phosphotyrosine protein specific phosphatase, PAP is a universal protein phosphatase hydrolyzing equally well the phosphotyrosine, serine, and threonine residues.

Acid Phosphatase↗
PubMed1991

Immunoreactivities for epidermal growth factor (EGF) and for EGF receptors in rats with gastric ulcers.

The present study was aimed at assessing whether epidermal growth factor (EGF) and its receptors are present in the gastric mucosa during the healing of gastric ulcers. Immunohistochemical, immunochemical and functional studies were performed in rats after induction of ulcers in the oxyntic mucosa. Controls, which included non-operated and sham-operated animals, displayed only rare cells in the bottom of the oxyntic glands showing EGF-like immunoreactivity. Within one day after ulcer induction, a markedly increased number of chief cells in undamaged mucosa showed intense staining. Concomitantly, there was an increased immunoreactivity for EGF receptors in the mucous neck cells. Maximal immunostaining for both compounds was observed at 3 days after ulcer induction; augmented staining was still demonstrable after 3 weeks. RIA revealed significantly increased EGF concentration in the oxyntic mucosa three days after ulcer induction, and at this stage stimulated gastric acid secretion, measured in a parallel group of chronic fistula rats, indicated significant inhibition. The transient increases in EGF-like and EGF receptor immunoreactivities may stimulate gland cell proliferation. The local release of EGF-like substances may also serve to reduce gastric acidity and thereby promote ulcer healing.

Animals↗
PubMed1991

Syringoid eccrine carcinoma.

Eccrine carcinomas are locally aggressive and have an infiltrative growth pattern. They have a variable clinical appearance and a diversity of histologic findings that often make the diagnosis difficult. The histologic findings, together with immunoperoxidase and enzyme histochemical studies, usually allow differentiation between eccrine carcinomas, other cutaneous neoplasms, and visceral adenocarcinomas with skin metastases. Provided there is no evidence of distant metastases, surgical excision is the treatment of choice. We report a case of syringoid eccrine carcinoma that was treated with Mohs micrographic surgery.

Adenocarcinoma↗
PubMed1991

Detection of IQ-type mutagens in canned roasted eel.

Basic extracts of canned roasted eel exhibited the highest mutagenicity among seven kinds of canned products assayed with Salmonella typhimurium TA98 in the presence of S-9 mix. The major mutagenic compounds of canned roasted eel extracts were purified and analysed by HPLC. The mutagenic fractions corresponding to the peaks of standard 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline(MeIQx) and 2-amino-3,7,8-trimethylimidazo[4,5-f]quinoxaline(7,8-DiMeIQx ) were further confirmed by the comparison of UV spectra, tester strain specificity and nitrite treatment. The estimated contents of MeIQx and 7,8-DiMeIQx were 1.1 ng and 5.3 ng per gram of canned roasted eel, respectively. Cooking temperature and time seemed to be the major factors affecting mutagen formation in fried eel. The type and amount of mutagenic compounds detected in canned roasted eel are likely to be correlated with the relative levels of specific free amino acids in raw eel.

Amino Acids↗
PubMed1991

Effect of emodin on cooked-food mutagen activation.

The herbs Rheum palmatum B and Polygonum cuspidatum S are frequently used as laxatives and anticancer drugs in Chinese medicine. The antimutagenic activity of these herbs as well as their active component emodin was examined in Salmonella typhimurium TA98. The crude extracts and emodin induced a dose-dependent decrease in the mutagenicity of benzo[a]pyrene (B[a]P), 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2). Furthermore, emodin reduced the mutagenicity of IQ by direct inhibition of the hepatic microsomal activation and not by interaction with proximate metabolites of IQ and/or by modification of DNA repair processes in the bacterial cell.

Animals↗
PubMed1991

The effect of extraction solvent on the mutagenicity of airborne particles.

Two different solvents (acetone and dichloromethane) were compared for their efficacy in extraction of mutagenic compounds from airborne particulate samples. Their mutagenicity was examined with Salmonella typhimurium TA98 in presence or absence of S9 mix. The total mutagenic activity of the acetone extract was 1.8-7.0-fold that of the dichloromethane extract. The content of 1-nitropyrene, 1,6-dinitropyrene, dibenzo[a,h]anthracene and indo[1,2,3-c,d]pyrene in acetone extracts of airborne particulate samples was 3.8-, 3.6-, 6.6- and 1135-fold that of dichloromethane extracts, respectively. 1,8-Dinitropyrene, benzo[a]pyrene, chrysene, benzo[a]fluoranthene, benzo [a] anthracene, and benzo[g,h,i]perylene were found in the acetone extract, but were negative in the dichloromethane extract under the same conditions. However, the amount of pyrene in the dichloromethane extract was much higher than in the acetone extract. These results indicate that the extraction efficacy of 1-nitropyrene, dinitropyrenes and benzo[a]pyrene is higher with acetone than with dichloromethane. This may be the reason why acetone is the most effective solvent in extraction of mutagens from airborne particulate samples.

Acetone↗
PubMed1991

Applications of microbial surfactants.

Biosurfactants are amphiphilic compounds produced by microorganisms that are capable of decreasing surface and interfacial tensions. They are useful in remediation of insoluble organic pollutants in soil and marine environments. There are also a large number of industrial uses for biosurfactants. This paper reviews recent research on applications of microbially-produced surfactants.

Journal Article↗
PubMed1991

A comparison of the growth promoting properties of ascitic fluids, cyst fluids and peritoneal fluids from patients with ovarian tumours.

The growth promoting properties of ascitic fluids, cyst fluids and peritoneal fluids from patients with ovarian malignancy, benign ovarian tumours and non-tumour related gynaecological conditions have been investigated using an ovarian carcinoma cell line (OAW 42), mesothelial cells (58MC) and rat kidney cells (NRK-49F). Colony stimulating activity (CSA) for tumour cells and transforming activity (TA) for mesothelial cells were weakly correlated, but whereas elevated TA was tumour-associated, CSA was not. However, TA was not cancer-associated and, although the difference between the mean TA values of benign and malignant cyst fluids was of borderline significance, some benign cyst fluids from cystadenomas showed high TA values. Higher levels of TA in the cystadenomas showed a significant correlation with the menopausal status of the patient and higher levels of TA in the malignant cyst fluid/peritoneal fluid groups were associated with more advanced disease. Results indicated that some fluids contained TGF-beta-like activity, but there was no direct evidence for the presence of TGF-alpha/EGF-like activity in the fluids. Heparin inhibited clonogenic growth of tumour cells but not mesothelial cells. The reduced CSA which was observed after treatment of fluids with both heparin and thrombin implicated coagulation factors in the manifestation of CSA. It was concluded that CSA in the fluids was due, at least partly, to fibrin coagulation, and TA was due to unknown growth factor(s) which may include TGF-beta-like activity. The results are discussed in the context of the aetiology of ovarian carcinoma, and the possible clinical significance of TA.

Animals↗
PubMed1991

Impact of dietary fatty acid supplementation on renal injury in obese Zucker rats.

We previously reported that renal injury in hyperlipidemic, obese Zucker rats was associated with a relative deficiency of tissue polyunsaturated fatty acids (PUFA). In the present study 10-week-old obese Zucker rats were pair fed regular chow or chow containing either 20% sunflower oil rich in n-6 PUFA, fish oil rich in n-3 PUFA, coconut oil medium-chain saturated fatty acid, or beef tallow long-chain saturated fatty acid. At 34 weeks of age there were comparable reductions in albuminuria, mesangial matrix expansion, and glomerulosclerosis in the fish oil and sunflower oil groups. While both fish oil and sunflower oil reduced serum triglycerides, and improved the composition of triglyceride-enriched lipoproteins, only fish oil decreased serum cholesterol. The effect of the dietary fatty acid supplementation on fatty acid profiles were similar in isolated glomeruli and cortical tissue. In general, the amelioration in injury in the fish oil and sunflower oil fed rats was most closely linked to glomerular levels of PUFA, either n-6 or n-3. These data suggest that hyperlipidemia and abnormalities in tissue FA are closely linked, and that dietary supplementation with PUFA may ameliorate chronic, progressive renal injury.

Albuminuria↗
PubMed1991

Accumulation of phosphocreatine and creatine in the cells and fluid of mouse seminal vesicles is regulated by testosterone.

We have recently established that phosphocreatine (PCr), a high-energy phosphate compound known to serve as an intracellular energy reserve, accumulates in the seminal vesicular fluid (SVF) of the mouse and the rat. To investigate whether the accumulation of PCr in the extracellular fluid of the seminal vesicles of mice is androgen-dependent, young adult mice (Swiss Webster, 6-7 wk old) were orchidectomized. Involution of the seminal vesicles following orchidectomy resulted in the total absence of SVF. Administration of testosterone propionate (TP) 2 wk later at a daily dose of 5 micrograms/g b.w. caused a rapid increase in the weights of seminal vesicle tissue (SVT) and SVF and also increased the concentration of PCr in SVF. The concentration of PCr in SVF increased rapidly from 3.0 mumol/g on Day 2 to a peak value of 11.1 +/- 0.5 mumol/g on Day 6. The increase in PCr concentration in SVF coincided with the enhanced rate of secretion of specific proteins by androgen-responsive epithelial cells. The creatine (Cr) concentration in SVF also increased from 12.6 mumol/g on Day 2 to 41.1 +/- 4.6 mumol/g on Day 8. The concentrations of PCr in SVF of TP-treated mice were about twice those in the age-matched intact controls. The concentrations of PCr and of Cr in SVT also increased from 1.1 +/- 0.5 mumol/g and 1.7 +/- 0.8 mumol/g, respectively, on Day 0 to the steady-state levels of 5.3 +/- 0.7 mumol/g and 14.8 +/- 2.7 mumol/g by Day 8. These results demonstrate that the accumulation of PCr in the fluid of mouse seminal vesicle is regulated by androgen.

Adenosine Triphosphate↗
PubMed1991

Plasma membrane Mg(2+)-ATPase of Pachysolen tannophilus: characterization and role in alcohol tolerance.

Following cell fractionation in sucrose density gradients, plasma membrane Mg(2+)-ATPase from Pachysolen tannophilus was studied. The ATPase displayed an apparent Km for ATP of 1.42 mM and was inhibited by high concentrations of Mg2+. The inhibitory effects of ethanol, 1-propanol, 1-butanol, and benzyl alcohol on Mg(2+)-ATPase were evaluated, and the concentration of each alcohol that inhibited ATPase activity by 50% (IC50) was determined. The IC50 decreased as the chain length of the alcohol increased. Moreover, the IC50 for ATPase activity was similar to the IC50 for growth rate, suggesting an association between impaired growth and ATPase inhibition. Almost complete inhibition of ATPase activity occurred at temperatures approaching 60 degrees C, and the optimal temperature was around 44 degrees C for ATPase from both control and ethanol-treated cells. Inclusion of 50 mM MgCl2 or CaCl2 in the medium did not rescue cells from the deleterious effects of ethanol.

1-Butanol↗