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Biomedical subjects

D Li

Publications and source records attributed to D Li.

At least 775 records · Page 43Linked to original sources
PubMed1994

[Prevalence of HIV and HCV among injecting drug users (IDUs) in Yunnan, China].

Prevalence of HIV and HCV was studied among 507 IDUs in Yunnan Province. The results reveal that sharing needles with other IDUs is one of the primary pathways to transmit both HIV and HCV. The rates of HIV and HCV infection in the IDU group is 66.5% and 94.9% respectively, which is significantly higher than those in the non-IDU group. There is a direct correlation between the rates of HIV and HCV antibody positive. 97.5% HCV (+) subjects are also HIV (+); and 57% HIV (+) subjects are HCV (+). It is suggested that all IDUs should be encouraged to stop using drugs to prevent HIV and HCV transmission.

Adult↗
PubMed1994

Antitumor activity of immunoconjugates composed of boanmycin and monoclonal antibody.

Boanmycin (bleomycin A6, BM), an antitumor antibiotic, was conjugated to monoclonal antibodies including R19, H111 and CCT2. The immunoconjugates exhibited selective cytotoxicity to related target cells including cecum cancer Hce-8693 cells, liver cancer BEL-7402 cells and leukemia CEM cells. They were highly effective against related human tumor xenografts in nude mice, and the inhibition rates by the conjugates were much higher than those by free BM. The inhibition rate by R19-BM conjugate against human cecum cancer xenografts reached 90%. BY immunoelectron microscopy, CCT2-BM conjugate showed specific binding and internalization in leukemia CEM cells. The results indicate that boanmycin-monoclonal antibody immunoconjugates are highly active both in vitro and in vivo.

Adenocarcinoma↗
PubMed1994

[Low frequency rotational responses in bilateral caloric weakness patients].

Comparative analysis of low frequency (0.01-0.64Hz) sinusoidal harmonic acceleration (SHA) responses of 50 patients with bilateral caloric weakness (summed slowphase velocities SSVs < or = 20 degrees/s) revealed that SHA stimuli reflected not only the existence of bilateral caloric weakness but also the impairment degree. The phase values of the patients with SSVs < or = 10 degrees/s were greater than that of the patients with SSVs > 10 degrees/s and the normals, and the gain values of the patients with SSVs < or = 10 degrees/s were smaller than those with SSVs > 10 degrees/s and the normals. The patients with SSVs < or = 10 degrees/s showed more severe impairments than those with SSVs > 10 degrees/s. However, even in the frequencies having higher impairment identifying rate, such as 0.01 and 0.02 Hz, about 30 percent of the patients with SSVs < or = 10 degrees/s revealed rotational responses that were within normal limits. These findings indicated that even marked bilateral caloric reduction is in sufficient to diagnose vestibular loss.

Caloric Tests↗
PubMed1994

[The significance of fascial tissue of the upper eyelid in double eyelidplasty].

The anatomical structure of fascial tissue of the upper eyelid is described in this article. It is emphasized that removing redundant fascial tissue is an important procedure in the double-eyelid operation of the upper eyelid. This is especially true for patients with baggy deformities or blepharochalasis. Based on this principle, 654 cases of double eyelidplasty were performed from 1990 to 1993 with satisfactory results revealed by postoperative follow-up of 1 month to 3 years.

Adolescent↗
PubMed1994

[Human parathyroid allotransplantation: comparison of donor grafts].

The authors compared the degrees of cell maturity, antigenicity and secretory function of parathyroid (PTG) tissues from cadavers (C-PTG), 20-28 wk fetus (F-PTG) and PTG adenoma (A-PTG). In A-PTG tissues, clustered or scattered immature cells were observed, but there were none in F-PTG and C-PTG. C-PTG and A-PTG tissues revealed better secretory function than F-PTG. No clear difference was found in HLA class I (ABC) antigen quantity among the three donor PTG tissues, but the amount of HLA class II (DR) antigen in A-PTG and F-PTG were significantly lower than that in C-PTG. The results demonstrate that C-PTG, with better function, and F-PTG, with lower antigenicity, can be used in clinical transplantation. A-PTG is not suitable for clinical transplantation due to their immaturity and possibility of carcinomatous change.

Adenoma↗
PubMed1994

[Effects of nifedipine on hepatic hyaluronic acid, hydroxyproline and glucosaminidase contents in rats with liver fibrosis].

In early stage treatment groups, Nifedipine (Nif) could significantly reduce hepatic hyaluronic acid (HA) and hydroxyproline (Hyp) contents in rats in which liver fibrosis had been induced by CCl4 treatment. N-acetyl-beta-glucosaminidase (beta-NAG) activity showed a similar change in the high dosage group. In late stage treatment groups, HA was reduced markedly, and decreased beta-NAG levels were noted in the high dosage group. These effects on HA, Hyp and beta-NAG were dependent on Nif dosage. The results suggest that Nif could inhibit the development of liver fibrosis in rats, and may even reverse it.

Acetylglucosaminidase↗
PubMed1994

Contents of trace elements in the hair of aplastic anemia patients and their treatment based on an overall analysis of symptoms and signs.

The content of 12 trace elements in the hair of 20 aplastic anemia patients was determined and compared with that of normal subjects as control. The results showed that patients with deficiency of yin had a significant decrease in lithium, calcium, strontium, and chromium, those with deficiency of yang had a distinct decrease in zinc magnesium barium, strontium, calcium, and lithium, and those with deficiency of both yin and yang had a general decrease in all the 12 trace elements. Changes in trace element content in hair may serve as a guide to opening up new vistas in the treatment of aplastic anemia on the basis of an overall analysis of symptoms and signs.

Adolescent↗
PubMed1994

Effects of kappa-selenocarrageenan on membrane fluidity and ghost reseal ability of rat erythrocyte.

Effects of kappa-selenocarrageenan (kappa-SeC) on membrane fluidity and ghost reseal ability of rat erythrocyte were studied by measuring the fluorescence polarization and the NADH-cytochrome C oxido-reductase, respectively. After rats were given ig kappa-SeC 140 mg.kg-1.d-1 x 30 d, the fluorescence polarization was decreased in comparison with saline control group (P < 0.05). It suggested that kappa-SeC increased the membrane fluidity. The reseal ability of erythrocyte membrane (ghost) was also elevated after ig kappa-SeC 140 and 70 mg.kg-1.d-1 x 30 d (P < 0.05).

Animals↗
PubMed1994

Removal of copper from the liver of Long-Evans Cinnamon (LEC) rats by tetrathiomolybdate (TTM) injection: the main excretion route is via blood, not bile.

Tetrathiomolybdate (TTM) was injected at a dose of 10 mg/kg bw daily for eight consecutive days into Long-Evans Cinnamon (LEC) rats, which inherently abnormally deposit Cu (260 micrograms/g) in the liver. The hepatic Cu (100 micrograms/g) and metallothionein (MT) bound Cu (from 2,600 to 540 micrograms/g protein) concentrations were decreased greatly by the injection. On the other hand, the renal Cu concentration increased significantly, but the brain Cu concentration only very slightly. The reduction of the hepatic Cu concentration was accompanied by reductions of Zn and Fe concentrations in the liver, kidney and brain. The TTM compound slightly stimulated excretion (about 3-fold) of Cu into the bile, but greatly (about 40-fold) into the blood. In rats not treated with TTM, most biliary (100%) and serum (78%) Cu was recovered in the trichloroacetic acid (TCA) soluble fraction. On the other hand, in rats treated with TTM, bile and serum Cu were recovered overwhelmingly in the TCA insoluble fraction, probably in the form of a Cu-TTM-albumin complex. Our results suggest that although there is an inherent failure in the intrinsic secretory process of Cu from the liver in LEC rats, the TTM compound can remove Cu from Cu-MT, resulting in a decrease of hepatic Cu.

Animals↗
PubMed1994

Role of hepatic copper-metallothionein on liver function of Long-Evans cinnamon rats with a new mutation causing hereditary hepatitis.

Liver slices from Wistar and Long-Evans Cinnamon (LEC) rats were incubated while open to the atmosphere to assess the liver function in LEC rats. Leakages of glutamic-oxaloacetic transaminase (GOT) and lactic dehydrogenase (LDH) into the medium were significantly lower in the LEC rat than in the Wistar rat. Furthermore, no pronounced enhancement of the concentration of thiobarbituric acid-reactive substances (TBARS) was found in the LEC rat. Hepatic Cu and Cu-metallothionein (Cu-MT) concentrations were 355.0 +/- 18.7 micrograms/g liver and 2559 +/- 181 micrograms/g protein in the LEC rats, whereas Wistar rats showed 4.1 +/- 0.1 Cu microgram/g liver accompanied by 16 +/- 4 micrograms/g protein of MT. The decrease of intrahepatic Cu-MT in LEC rats was stimulated by incubation with Fenitrilotriacetate (Fe-NTA). There was a direct correlation between the enhancement of TBARS and disappearance of Cu-MT. Our results suggest that hepatic Cu-MT in LEC rats protects against liver injury stimulated by oxidative stress.

Animals↗
PubMed1994

[Scanning electron microscopical study of trachea vasculature in the human fetus].

The microvasculature of the human fetal trachea was studied in vascular casts viewed in a scanning electron microscope (SEM). The trachea is supplied by longitudinal vascular bundles running at both sides of the organ, including both longitudinal tracheoesophageal arteries and veins. They are the source of the segment vascularization of the trachea. Due to numerous arteriovenous anastomoses and anastomoses occurring within respective arterious and venous vascular systems, a constant blood flow within submucous capillary plexus and the tracheal wall is provided. A characteristic feature of tracheal vascularization is a very rich, dense network of vein.

Corrosion Casting↗
PubMed1994

The effect of age on dendrites in the rat superior cervical ganglion.

Intracellular injection of a biotinylated probe in fixed superior cervical ganglia followed by confocal microscopy was used to investigate the effects of age on the dendritic arborisation of sympathetic neurons in rats aged 6 wk (young adult), 7 months (fully grown adult) and 24 months (aged). In accordance with other studies considerable dendritic growth was observed during postnatal development. However, in old age dendritic growth did not continue, and significant atrophy was observed. Quantitation of neuronal morphology showed significant reductions in soma size, total dendritic length, number of branch points and total area of dendritic arborisation in old age. Unexpectedly, significant reductions in the numbers of primary dendrites were observed in maturity and in old age. Concomitant with this atrophy there was an increase in age-related morphological abnormalities. The similarities between the atrophy and dendritic abnormalities shown by our aged neurons and those seen in other studies of young adult sympathetic neurons following axotomy or trophic factor deprivation are discussed.

Aging↗
PubMed1993

Regulation of cytochrome P450 2B1/2 genes by diallyl sulfone, disulfiram, and other organosulfur compounds in primary cultures of rat hepatocytes.

Our previous study demonstrated that diallyl sulfide (DAS), a compound derived from garlic, transcriptionally activated the P450 2B1/2 genes in rat liver. In the present study, rat primary hepatocytes were used to determine the effects of DAS and its metabolite, diallyl sulfone (DASO2), on the expression of the P450 2B1/2 genes. Freshly isolated adult rat hepatocytes were cultured in a serum-free medium on a reconstituted basement membrane matrix "matrigel" that enabled the hepatocytes to maintain expression of numerous liver-specific genes for more than 1 week. After 48-hr of acclimation, 0.1, 0.5, and 2.0 mM concentrations of DAS or DASO2 were added to the culture medium and the cells were harvested at 4, 12, 24, or 36 hr after the treatment for the preparation of microsomes and RNA. Cytotoxicity was not observed by morphological examinations after DAS and DASO2 treatments. In contrast to the in vivo results, there was only a slight increase in the levels of P450 2B1/2 mRNA and protein in DAS-treated cells. However, DASO2 treatment (2 mM) resulted in 11-, 21-, and 22-fold increases in P450 2B1/2 mRNA levels at 12, 24, and 36 hr after the treatment, respectively. P450 2B1/2 protein levels were also increased markedly in DASO2-treated cells. Co-incubation of the rat hepatocyte cultures with a physiological concentration of growth hormone significantly blocked the induction of P450 2B1/2 mRNA by DASO2. Northern blot analysis using oligonucleotide probes specific for 2B1 and 2B2 demonstrated that DASO2 induced mRNA levels of both 2B1 and 2B2, with a greater induction of 2B1 mRNA. For comparison, the effects of disulfiram (DSF) and its metabolite, diethyldithiocarbamate (DDTC), on P450 2B1/2 mRNA expression were also examined in the cultured rat hepatocytes. Both DSF and DDTC caused a significant increase in P450 2B1/2 mRNA level with the highest induction at 0.5 mM. Addition of growth hormone to the culture effectively suppressed the P450 2B1/2 mRNA induction by DSF but had little effect on the induction by DDTC. Neither mRNA nor protein levels of P450 2E1 in cultured hepatocytes were affected by all the organosulfur compounds tested. These results suggest that DASO2, DSF and DDTC selectively modulate P450 isozymes in cultured rat primary hepatocytes and that the induction of P450 2B1/2 by DAS in rat liver may be mediated by its metabolite, DASO2.

Allyl Compounds↗