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Biomedical subjects

C L Li

Publications and source records attributed to C L Li.

At least 73 records · Page 4Linked to original sources
PubMed1997

Comparison of the prevalence in two diabetes surveys in Pu-Li, Taiwan, 1987-1988 and 1991-1992.

The objective of this study was to investigate the prevalence of non-insulin-dependent diabetes mellitus (NIDDM) in Pu-Li, Taiwan from 1991-1992, and to compare the results with a similar study conducted in 1987-1988. We also wished to compare different approaches in asking about patient history and to determine how this effects data authenticity. Both were community-based cross-sectional studies with stratified cluster sampling of residents age > or = 30. Blood samples were taken for screening and 75 g oral glucose tolerance tests were performed for diagnosis. The total number of eligible subjects in the second study was 2719 (1424 men, 1295 women). Complete data and samples were collected for 1118 (536 men, 582 women). The response rate was 41.1% (37.6% for men, 44.9% for women). The crude prevalence was 10.3% (5.6% known, 4.7% new). Using standard world population (Segi), the age-adjusted prevalence rate was 8.3% (4.0% known, 4.3% new). The 1991-1992 study had a response rate (crude 41.1%, adjusted 51.3%) which was slightly lower than the 1987-1988 study (crude 44.8%, adjusted 55.9%). The age-adjusted prevalence rates for new NIDDM were similar (4.4 vs. 4.3%) while the age-adjusted prevalence of known NIDDM in the second survey (4.0%) was lower than the first survey (6.9%), which apparently was overestimated due to the simplicity of questions regarding history. In conclusion, prevalence of new DM in this area appears to be stable, and when doing a survey regarding previous DM, it is better to include treatment history rather than depending on self-reporting of NIDDM alone.

Administration, Oral↗
PubMed1997

The bioavailability of ginkgolides in Ginkgo biloba extracts.

A new Ginkgo biloba leaf extract, BioGinkgo 27/7, was prepared using a method that enriches ginkgolide B. The bioavailability of ginkgolides in these extracts was assessed in rabbits in comparison with a commercially available standardized 24/6 extract. It was found that, after a single dose, a higher concentration of ginkgolides was maintained for a longer period of time with these extracts than was found with commercial extract prepared by existing methods.

Animals↗
PubMed1997

Pharmacokinetics of 2-naphthol following intrapericardial administration, and formation of 2-naphthyl-beta-D-glucoside and 2-naphthyl sulphate in the American lobster, Homarus americanus.

1. Following a 0.25-mg/kg intrapericardial dose of the phenolic compound, 2-naphthol, to the American lobster, Homarus americanus, a two-compartment model best described the disposition of parent [14C]-2-naphthol in the haemolymph. Male and female lobsters had similar alpha-phase half lives of 26 +/- 19 min (mean +/- SD, n = 4) and 29 +/- 15 min respectively. The beta-phase half lives were significantly longer in males, 63.9 +/- 30.9 h, than in females, 30.6 +/- 6.8 h (p < 0.05). The total body clearance for females was 26.4 +/- 6.5 ml x h-1 x kg-1 and was higher than that of males, 11.1 +/- 5.9 ml x h-1 x kg-1 (p < 0.05). 2. 2-Naphthol was converted to 2-naphthyl-beta-D-glucoside (major metabolite) and 2-naphthyl sulphate (minor metabolite) such that at 24 h 39-60.6% of the radioactivity in haemolymph was 2-naphthyl-beta-D-glucoside, 38.6-58.9% 2-naphthol and 0.5-4% 2-naphthyl sulphate. 3. The 2-naphthol-derived radioactivity was > 99% bound to haemolymph proteins at 1 min and > 90% bound at 1 day after the dose, indicating that both 2-naphthol and 2-naphthyl-beta-D-glucoside were highly protein bound. 4. 2-Naphthyl-beta-D-glucoside was slowly eliminated from haemolymph in both males and females, with elimination half lives of 34-78 h. 2-Naphthyl-beta-D-glucoside was the major metabolite in urine samples collected at 5 days after the dose. Hepatopancreas and antennal gland contained glucosidase activities, and the long half life of 2-naphthyl-beta-D-glucoside could be explained by conjugation deconjugation cycling. 5. 2-Naphthyl sulphate was eliminated from haemolymph with a half-life < 10 h and was excreted in urine.

Animals↗
PubMed1997

[Nursing study of supporting aerosolized oxygen by combined drug liquid in children with intensive pneumonia].

148 cases of critical pneumonia at the same period were divided into two groups randomly and supplied by two oxygen therapeutic methods. The study group has 75 cases, whom were given aerosolized oxygen with antibacterial, antiphlogistic drugs, expectorants, antispastic and antiasthmatic drugs, and compared with 73 cases of convenient simple with aerosolized oxygen inhalation. The results showed the frequency, time and starting effect time of inhaling oxygen in two groups have significant difference (P < 0.001) and the alteration of SaO2 and the therapeutic effect in two groups also have significant difference (P < 0.05, P < 0.005 respectively). The total effectual rates of the study and control group were 94.66% and 73.94% respectively. The difference between the duration of hospitalization and the therapeutic expenditure in two groups were significance (P < 0.01, P < 0.05 respectively). The study indicated that aerosolized oxygen combined drug liquid is a better oxygen therapy method for treating pneumonia.

Administration, Inhalation↗
PubMed1997

[Inhibition of gastric motility by microinjection of CCK-8 into rat amygdala].

Intranulear microinjection and electrical stimulation technique were employed to evaluate the effect of ventromedial hypothalamus (VMH) on the gastric inhibition elicited by basomedial amygdala nucleus (BMA) excitation. The results were as follows: (1) Microinjections of CCk-8 (50 ng/microliter) into bilateral BAM resulted in significant decrease in intragastric pressure (IGP) and gastric motility frequency (GMF) (P < 0.01). (2) Neither CCK-A receptor antagonist [L364, 718] nor CCK-8 receptor antagonist [L365, 260] induced effects on IGP or GMF when given alone. (3) If bilateral BMA were pretreated with [L364, 718], CCK-8 could no longer induce any inhibitory effects, whlie [L365, 260] had no similar suppressive effect. (4) The inhibitory effects were not found in other nuclei in the amygdaloid body, such as bed nucleus of the stria terminalis intramygdaloid (BSTIA) and amygdaloid nucleus medial (Me). (5) Electrical stimulation of unilateral VMH or BMA would result in the inhibition of IGP and GMF. (6) After electric coagulation of VMH unilateraly injection of CCK-8 to or stimulation of homolateral VMH could no longer inhibite IGP or GMF. The above results suggest that in BMA CCK-8 exerts inhibitory effect on both motility and intragastric pressure through CCK-A receptors.

Amygdala↗
PubMed1996

Thymic dendritic cell precursors: relationship to the T lymphocyte lineage and phenotype of the dendritic cell progeny.

Successive T-precursors isolated from adult mouse thymus were examined for their developmental potential, by transfer to irradiated Ly 5-disparate recipients. The earliest, "low CD4" precursors formed T, B, and dendritic cells (DC), but not myeloid cells, in accordance with earlier studies. Surprisingly, the next downstream CD4-8-3 44+25+ precursor population still formed DC as well as T cells although it no longer formed B or myeloid cells. Further down-stream, the CD4-8 3-44-25+ population formed only T cells. The thymic and splenic DC progeny of the early thymic precursors all expressed high levels of CD8 alpha, in contrast with normal splenic DC and the splenic DC progeny of bone marrow stem cells, which consisted of both CD8 and CD8+ DC. A common precursor of T cells and of a subclass of DC is proposed, with CD8 alpha as a marker of the lymphoid-related DC lineage.

Animals↗
PubMed1996

Comparison of the efficacy of tropisetron versus a metoclopramide cocktail based on the intensity of cisplatin-induced emesis.

Cisplatin-induced emesis is one of the most feared side effects in cancer treatment. High-dose metoclopramide may prevent only 30-40% of cases of acute emesis. Investigations to test the efficacy of new antiemetics are mandatory. We compared the efficacy, toxicity, and patients' preference for tropisetron, a new 5-hydroxytryptamine3 (HT3) receptor antagonist, with those of a combination of high-dose metoclopramide, dexamethasone, diphenhydramine, and lorazepam (metoclopramide cocktail) in a randomized crossover study for the control of nausea and vomiting during cisplatin-containing chemotherapy. A total of 62 chemotherapy-naive women were included and followed over 3 consecutive courses. Detailed analysis comparing the incidence of acute emesis for each 4 h period following cisplatin infusion was also performed. Complete protection from acute emesis was obtained in 48% of patients receiving tropisetron and 29% of patients receiving the metoclopramide cocktail over the first two courses of chemotherapy (P = 0.029). When the frequency of acute emesis in all patients was compared on a daily basis, no significant difference was found. When emesis frequency was compared over each 4 h period following infusion of cisplatin, tropisetron was superior to the metoclopramide cocktail during the first, the second, and the first and second periods (P = 0.0001, P = 0.01 and P = 0.0006, respectively). This superiority reversed after 12 h but did not reach statistical significance (P = 0.112). Tropisetron was more effective in controlling acute nausea, but metoclopramide provided better control of delayed emesis. A drop in efficacy over successive courses was observed in patients receiving metoclopramide first but was not seen in tropisetron-first patients. A tendency for tropisetron preference was observed. Tropisetron is more effective than the metoclopramide cocktail in the control of chemotherapy-induced vomiting within 8 h of the implementation of cisplatin and in the control of nausea on the 1st day. To improve the control of chemotherapy-induced emesis, further investigations on the additional tropisetron dosing at 8 h after cisplatin infusion or the combination use of tropisetron and other antiemetics by a continuous 4 h period of observation and comparison are mandatory.

Adult↗
PubMed1996

[Expression of cDNA of human chorionic gonadotropin beta-subunit (beta-hCG) cDNA in insect cells and effect of expressed product on mouse lymphocytes in vitro].

Expression vector pVL 1393-hCG beta containing beta-hCG cDNA has been constructed using an unfused protein nuclear polyhedrosis virus (AcNPV) expression vector. The insect cells (Sf 9) were cotransfected by the expression vector and nuclear polyhedrosis virus genomic DNA, and recombinant virus AcNPV-hCG beta was screened out, beta-hCG cDNA was expressed in insect cells infected by recombinant virus and recombinant beta-hCG (r beta-hCG) was secreted into medium. The purity of r beta-hCG, purified by immuno-affinity chromatography, was about 90% and the molecular weight of r beta-hCG was 22,500 Da. Like hCG, r beta-hCG suppressed significantly proliferation of induced lymphocytes, as well as production of IL-2 to some extent, on a parallel with suppression of lymphoproliferation.

Animals↗
PubMed1995

Biotransformation, hepatopancreas DNA binding and pharmacokinetics of benzo[a]pyrene after oral and parenteral administration to the American lobster, Homarus americanus.

It has been shown that American lobsters, (Homarus americanus) environmentally exposed to polycyclic aromatic hydrocarbons do not develop tumors or neoplastic changes although finfish exposed under identical conditions do develop cancer. In this study, environmentally relevant doses (nominally 50 micrograms/kg) of a radiolabelled model procarcinogen, benzo[a]pyrene (BaP), were administered i.v. or p.o. to lobsters and the fate of the radiolabel examined. Parent BaP was rapidly distributed from hemolymph into tissues after i.v. administration. Following oral administration, hemolymph concentrations of BaP rose slowly and reached levels similar to those found after i.v. administration by 48 h after the dose. The tissue distribution of BaP residues was determined at 3 days, 2 weeks and 4 weeks after the p.o. dose and 2 weeks after the i.v. dose. There was no route-related difference in tissue concentrations of BaP residues at 2 weeks. At all times, most of the retained BaP residues were in hepatopancreas (25-75% administered dose) or muscle (8-42% administered dose). Greater than 93% of the radioactivity in muscle was parent BaP at all studied times and the mean concentration of BaP residues in muscle was constant over the period of study. Although most of the radioactivity in hepatopancreas was BaP, metabolites were found and BaP residues declined with time. DNA isolated from hepatopancreas showed extremely low levels of BaP-metabolite binding, 0.016 +/- 0.013 pmol BaP equivalents/mg DNA, mean +/- S.D., n = 11. These studies show that BaP from dietary sources is retained for long periods by edible lobster tissues and suggest that a major reason for the resistance of American lobsters to polycyclic aromatic hydrocarbon-induced cancers is the very slow phase 1 metabolism to reactive metabolites.

Administration, Oral↗
PubMed1995

Murine hematopoietic stem and progenitor cells: I. Enrichment and biologic characterization.

Murine bone marrow cells were fractionated by fluorescence-activated cell sorting into Rh123lo Lin- c-kit+ Ly6A+, Rh123hi Lin-c-kit+ Ly6A+, and Lin- c-kit+ Ly6A- populations within which most, if not all, of the hematopoietic activities of the marrow resided. The Rh123lo Lin- c-kit+Ly6A+ cells, which consist exclusively of small- or medium-sized lymphocyte-like cells, are highly enriched for long-term hematopoietic in vivo repopulating cells. The enrichment factor for these cells from the marrow was estimated as 2,000-fold. The Rh123hi Lin- c-kit+ Ly6A+ cells, although also highly enriched for day-12 spleen colony-forming units, were relatively depleted of long-term in vivo repopulation capacity. Most, if not all Lin- c-kit+ Ly6A- cells were Rb123hi. In contrast to both Rh123lo and Rh123hi Lin- c-kit+ Ly6A+ stem cell populations, the Lin- c-kit+ Ly6A- cells can be stimulated to proliferate in vitro in the presence of single cytokines, which is a characteristic of committed progenitor cells. No marked synergistic interactions between individual cytokines were observed with this cell population. Both Rh123hi Lin- c-kit+ Ly6A+ mature stem cell and Lin- c-kit+ Ly6A- progenitor cell populations displayed in vivo repopulation kinetics resembling those of the putative short-term hematopoietic repopulating cells.

Animals↗
PubMed1995

Lipid peroxidation in brain: interactions of L-DOPA/dopamine with ascorbate and iron.

Recent reports have stressed an accumulation of iron and enhanced levels of lipid peroxides in the substantia nigra as essential factors in the pathogenesis of Parkinson's disease. Many investigators believe that tissue antioxidants, such as ascorbate, play a protective role. On the other hand, L-DOPA, which is used extensively to treat Parkinson's disease, undergoes autoxidation (as does dopamine), thus generating reactive oxygen species. We studied lipid peroxidation (LPO) in mouse brain homogenates and evaluated the effects of iron (5 microM ferric-ADP), L-DOPA, dopamine and ascorbic acid, added either alone or in mixtures. Ascorbic acid was used at levels of 0.5 mM or 2.0 mM, approximating those present normally in brain. LPO in brain homogenates was stimulated by the addition of either ascorbic acid or iron, as well as by a combination of the two, in agreement with other reports. The effects of L-DOPA were complex: L-DOPA strongly suppressed LPO both with and without added iron-ADP. In sharp contrast, however, when ascorbic acid was also added, L-DOPA no longer suppressed LPO; indeed, L-DOPA stimulated LPO in the presence of added iron and ascorbic acid. Dopamine behaved similarly to L-DOPA. When ascorbic acid was studied over a concentration range, LPO was stimulated at 0.5, 1, 2 or 3 mM, with or without added iron and/or dopamine; 5 and 10 mM ascorbic acid were either not as effective or suppressed LPO below control levels. Deferoxamine, a powerful iron chelator, greatly suppressed LPO under all conditions, as did diethylenetriaminepentaacetate (DTPA). Added superoxide dismutase had no effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Purified murine long-term in vivo hematopoietic repopulating cells are not prothymocytes.

Analysis of kinetics of thymic repopulation by Rh123low, Lin-, Ly6A/E+, c-kit+ (Rh123low) cells, highly enriched for long-term in vivo hematopoietic repopulating cells, reveals that this population is deficient in thymic repopulation at week 3 after intravenous transplantation when compared to normal bone marrow cells. This suggests that the marrow prothymocytes have been depleted from this population, and analysis of thymic repopulation at week 3 can therefore be used to differentiate prothymocytes and their precursors. Using this short-term assay, the Rh123high, Lin-, Ly6A/E+, c-kit+ (Rh123high) population has been found to be relatively more efficient at early thymic repopulation, suggesting that this population contains the prothymocytes. In addition, the differentiation potential and reconstitution behavior of the Rh123high population observed after intravenous and intrathymic transfer strongly indicates that this population is at the transitional stage between the marrow primitive pluripotential and thymic more mature lymphoid restricted stem cells. We propose that the thymic repopulating ability of the Rh123low population is through generation of the more mature Rh123high progeny, presumably in the marrow.

Animals↗
PubMed1995

[Expression of the extracellular domain (1-341) of rat ovarian lutropin receptor in insect cells and preliminary characterization of the expressed product].

Extracellular domain residues 1-341 (designed R 341) of luteinizing hormone/human chorionic gonadotropin receptor (LH/hCG receptor) has high binding affinity for ligand. This paper describes expression of cDNA coding for R 341 in insect cells and preliminary identification of the expressed protein. SDS-PAGE silver staining and immunoblotting analysis show expressed product appears in two bands, major band has molecular weight 38.5 Kd, and weak band, 40.0 Kd. Ligand binding immunoblotting and 125I-hCG-binding blotting analysis indicate that expressed product R 341 has specific binding affinity for ligand. Ligand binding assay and Scatchard analysis indicate that recombinant receptor R 341 has high binding affinity for hCG and Kd is 5.68 x 10(-10) mol/L.

Animals↗
PubMed1994

Stem cell factor enhances the survival but not the self-renewal of murine hematopoietic long-term repopulating cells.

The effects of stem cell factor (SCF) have been tested on a murine bone marrow subpopulation (RH123lo, Lin-, Ly6A/E+) that is highly enriched for long-term hematopoietic repopulating cells. SCF maintained cells from this population with long-term repopulating ability for up to 10 days in vitro. However, compared with freshly isolated cells, the level of engraftment in vivo by the cultured cells declined during the in vitro culture period, suggesting that SCF alone was unable to stimulate the self-renewal of long-term repopulating cells. By direct visualization of cultures, only small numbers of cells survived and rarely underwent cell division. However, SCF did directly stimulate proliferation of a population (Rh123med/hi,Lin-,Ly6A/E+) enriched for short-term repopulating cells. These data suggest that stem cell differentiation is associated with the development of mitogenic activity by SCF at least in some progenitor cell populations.

Animals↗
PubMed1994

[Treatment of bladder cancer by Nd:YAG laser local irradiation and whole-bladder photodynamic therapy with hematoporphyrin derivative].

Twenty cases with 51 tumor foci of urinary bladder were treated by Nd:YAG laser local irradiation plus whole-bladder photodynamic therapy (PDT) with hematoporphyrin derivative (HPD). All cases were confirmed by histopathological diagnosis. Of the 20 patients, 19 were cured after one treatment (95%) and the other patient cured after 2 treatments within 40 days. On follow-up for 3-23 months, tumor recurrence occurred in 2 cases (10%) about 3-6 months after treatment. The results suggest that the PDT effect in destroying bladder tumors might be enhanced by Nd:YAG laser while the lesions escaped Nd:YAG laser irradiation could be handled by whole-bladder PDT.

Adult↗
PubMed1994

Determination of pyrethroids in human urine by gas chromatography.

A gas chromatographic method for the determination of deltamethrin and fenvalerate in human urine is described. Both deltamethrin and fenvalerate have been analysed by gas chromatography with a electron capture detector. The least detectable concentration of both pyrethroids in urine is 0.2 g per litre. The precision and accuracy of the method were within acceptable limits. The method has been used to determine the pyrethroids in urine samples obtained from packers, spraymen and acute pyrethroids poisoning patients.

Chromatography, Gas↗