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Biomedical subjects

Y Huang

Publications and source records attributed to Y Huang.

At least 631 records · Page 35Linked to original sources

Structural changes in rat aortic intima due to transmural pressure.

Huang et al. (1997) propose a new hypothesis and develop a mathematical model to explain rationally the in vitro and in situ measured changes (Tedgui and Lever, 1984; Baldwin and Wilson, 1993) in the hydraulic conductivity of the artery wall of rabbit aorta with transmural pressure. The model leads to the intriguing prediction that this hydraulic conductivity would decrease by one half if the thin intimal layer between the endothelium and the internal elastic lamina volume-compresses approximately fivefold. This paper presents the first measurements of the effect of transmural pressure on intimal layer thickness and shows that the intimal matrix is, indeed, surprisingly compressible. We perfusion-fixed rat thoracic aortas in situ with 2 percent glutaraldehyde solution at 0, 50, 100, or 150 mm Hg lumen pressure and sectioned for light and electron microscopic observations. Electron micrographs show a dramatic, nonlinear decrease in average intimal thickness, i.e., 0.62 +/- 0.26, 0.27 +/- 0.14, 0.15 +/- 0.10, and 0.12 +/- 0.07 (SD) micron for 0, 50, 100, and 150 mm Hg lumen pressure, respectively. The volume strain of the intima is more than 20 times greater than the radial strain of the artery wall due to hoop tension and two orders of magnitude greater than the consolidation of the artery wall as a whole assuming constant medial density (Chuong and Fung, 1984). Moreover, in both light and electron microscopic observations, it is easy to find numerous sites where the endothelium puckers into the fenestral pores at high lumen pressure, as predicted by the theory in Huang et al. (1997). In contrast, the average diameter of a fenestral pore increases only 10 percent as the lumen pressure is increased from 0 to 150 mm Hg. These results indicate that the thin intimal layer comprising less than 1 percent of the wall thickness can have a profound effect on the filtration properties of the wall due to the large change in Darcy permeability of the layer and the large reduction in the entrance area of the flow entering the fenestral pores, though the pores themselves experience only a minor enlargement due to hoop tension.

Animals↗

Chemokine coreceptor usage by diverse primary isolates of human immunodeficiency virus type 1.

We tested chemokine receptor subset usage by diverse, well-characterized primary viruses isolated from peripheral blood by monitoring viral replication with CCR1, CCR2b, CCR3, CCR5, and CXCR4 U87MG.CD4 transformed cell lines and STRL33/BONZO/TYMSTR and GPR15/BOB HOS.CD4 transformed cell lines. Primary viruses were isolated from 79 men with confirmed human immunodeficiency virus type 1 (HIV-1) infection from the Chicago component of the Multicenter AIDS Cohort Study at interval time points. Thirty-five additional well-characterized primary viruses representing HIV-1 group M subtypes A, B, C, D, and E and group O and three primary simian immunodeficiency virus (SIV) isolates were also used for these studies. The restricted use of the CCR5 chemokine receptor for viral entry was associated with infection by a virus having a non-syncytium-inducing phenotype and correlated with a reduced rate of disease progression and a prolonged disease-free interval. Conversely, broadening chemokine receptor usage from CCR5 to both CCR5 and CXCR4 was associated with infection by a virus having a syncytium-inducing phenotype and correlated with a faster rate of CD4 T-cell decline and progression of disease. We also observed a greater tendency for infection with a virus having a syncytium-inducing phenotype in men heterozygous for the defective CCR5 Delta32 allele (25%) than in those men homozygous for the wild-type CCR5 allele (6%) (P = 0.03). The propensity for infection with a virus having a syncytium-inducing phenotype provides a partial explanation for the rapid disease progression among some men heterozygous for the defective CCR5 Delta32 allele. Furthermore, we did not identify any primary viruses that used CCR3 as an entry cofactor, despite this CC chemokine receptor being expressed on the cell surface at a level commensurate with or higher than that observed for primary peripheral blood mononuclear cells. Whereas isolates of primary viruses of SIV also used STRL33/BONZO/TYMSTR and GPR15/BOB, no primary isolates of HIV-1 used these particular chemokine receptor-like orphan molecules as entry cofactors, suggesting a limited contribution of these other chemokine receptors to viral evolution. Thus, despite the number of chemokine receptors implicated in viral entry, CCR5 and CXCR4 are likely to be the physiologically relevant chemokine receptors used as entry cofactors in vivo by diverse strains of primary viruses isolated from blood.

Animals↗

Persistent antibody responses but declining cytotoxic T-lymphocyte responses to multiple human immunodeficiency virus type 1 antigens in a long-term nonprogressing individual with a defective p17 proviral sequence and no detectable viral RNA expression.

Long-term nonprogressor AD-18 has been infected with human immunodeficiency virus type 1 (HIV-1) for at least 16 years. During the past 5 years, he has had undetectable levels of plasma viremia, and HIV-1 cannot be isolated from him. Sequencing of proviral DNA indicates that the only HIV-1 sequences that can be identified in AD-18 have gross defects in the p17-encoding regions of the gag gene (Y. Huang, L. Zhang, and D. D. Ho, Virology 240:36-49, 1998). However, AD-18 has strong, sustained antibody responses to several HIV-1 antigens, including p17. Cytotoxic T-lymphocyte responses to Env and Gag antigens have gradually diminished over the past 4 years, at a time when the titers of antibodies to the same proteins have remained stable. We discuss what these observations might mean for the generation and maintenance of immunological memory.

Dendritic Cells↗

The role of nucleocapsid and U5 stem/A-rich loop sequences in tRNA(3Lys) genomic placement and initiation of reverse transcription in human immunodeficiency virus type 1.

We have studied the effect of mutations in the human immunodeficiency virus type 1 (HIV-1) nucleocapsid (NC) sequence on tRNA(3Lys) genomic placement, i.e., the in vivo placement of primer tRNA(3Lys) on the HIV-1 primer binding site (PBS). HIV-1 produced from COS cells transfected with wild-type or mutant proviral DNA was used in this study. We have found that mutations in the amino acid sequences flanking the first Cys-His box in the NC sequence produce the maximum inhibition of genomic placement. A similar finding was obtained when the NC-facilitated annealing of primer tRNA(3Lys) to the HIV PBS in vitro was studied. However, since the genomic placement of tRNA(3Lys) occurs independently of precursor protein processing, the NC mutations studied here have probably exerted their effect through one or both of the precursor proteins, Pr55gag and/or Pr160(gag-pol). One mutation in the linker region between the two Cys-His boxes, P31L, prevented packaging of both Pr160(gag-pol) and tRNA(3Lys) and prevented the genomic placement of tRNA(3Lys). Both packaging and genomic placement were rescued by cotransfection with a plasmid coding for wild-type Pr160(gag-pol). For other linker mutations [R7R10K11 S, R32G, and S3(32-34)], packaging of Pr160(gag-pol) and tRNA(3Lys) was not affected, but genomic placement was, and placement could not be rescued by cotransfection with plasmids coding for either Pr55gag or Pr160(gag-pol). After placement, the initiation of reverse transcription within extracellular virions is characterized by a 2-base DNA extension of the placed tRNA(3Lys). This process requires precursor processing, and those NC mutations which showed the most inhibition of initiation were in either of the two NC Cys-His boxes. Destabilization of a U5 stem-A-rich loop immediately upstream of the PBS (through deletion of four consecutive A's in the loop) did not affect the in vivo genomic placement of tRNA(3Lys) but resulted in the presence in the extracellular virus of longer cDNA extensions of tRNA(3Lys), with a corresponding decrease in the presence of unextended and 2-base-extended tRNA(3Lys).

Amino Acid Sequence↗

Association of petrochemical exposure with spontaneous abortion.

OBJECTIVES: To assess the association between petrochemical exposure and spontaneous abortion, a retrospective epidemiological study in a large petrochemical complex in Beijing, China was conducted. METHODS: Plant employment records identified 3105 women who were married, were 20-44 years of age, and had never smoked. Of those, 3070 women (98.8%) reported at least one pregnancy. From this group, 2853 (93%) of the women participated in the study. According to their plant employment record, about 57% of these women workers reported occupational exposure to petrochemicals during the first trimester of their pregnancy. Trained interviewers administered a standardised questionnaire to this group of women and their husbands, collecting information on reproductive history, pregnancy outcomes, employment history, occupational exposure, smoking habits, alcohol consumption, indoor air pollution, and demographic variables. The results from the womens' first pregnancies were analysed. RESULTS: There was a significantly increased risk of spontaneous abortion for women working in all of the production plants with frequent exposure to petrochemicals (8.8%; range of 5.8%-9.8%) compared with those working in nonchemical plants (2.2%; range of 0.0%-7.1%). Also, when a comparison was made between exposed and non-exposed groups within each plant, exposure to petrochemicals was consistently associated with an increased risk of spontaneous abortion. The overall odds ratio (OR) was 2.7 (95% confidence interval (95% CI) 1.8 to 3.9) after adjusting for potential confounders. When the analysis was performed with the exposure information obtained from the women' interview responses for (self reported) exposures, the estimated OR for spontaneous abortions was 2.9 (95% CI 2.0 to 4.0). The analysis was repeated by excluding those 452 women who provided inconsistent reports between recalled exposure and work history, and a comparable risk of spontaneous abortion (OR 2.9; 95% CI 2.0 to 4.4) was found. In analyses for exposure to specific chemicals, an increased risk of spontaneous abortion was found with exposure to most chemicals, and the results for benzene (OR 2.5; 95% CI 1.7 to 3.7), gasoline (OR 1.8; 95% CI 1.1 to 2.9), and hydrogen sulphide (OR 2.3; 95% CI 1.2 to 4.4) were significant. CONCLUSION: An increased risk of spontaneous abortion was found associated with the exposure to petrochemicals, including benzene, gasoline, and hydrogen sulphide.

Abortion, Spontaneous↗

Contractile and relaxant effects of tetrapentylammonium ions in rat isolated mesenteric artery.

Both contractile and relaxant responses to tetrapentylammonium ions (TPA+) were studied in rat isolated mesenteric artery. TPA+ (5-10 micromol/l) caused a sustained increase of muscle tension. The contractile effect of TPA+ (10 micromol/l) was dependent upon the presence of extracellular Ca2+ but independent of the presence of endothelium. TPA+ (10-50 micromol/l) induced biphasic contraction, and the amplitude of peak and sustained tension decreased with increasing TPA+ concentration. TPA+ (100-300 micromol/l) only produced monophasic contraction. TPA+ (50 micromol/l) abolished the transient contraction induced by caffeine (10 mmol/l) or phenylephrine (1 micromol/l) in the absence of extracellular Ca2+. Nifedipine and verapamil concentration-dependently reduced the TPA+-induced contraction with respective IC50 values of 1.34 +/- 0. 24 and 9.46 +/- 1.36 nmol/l, these values were similar to 1.35 +/- 0. 21 and 16.07 +/- 1.71 nmol/l, respectively, for the inhibitory effects of nifedipine and verapamil on the high K+ (60 mmol/l)-induced contraction. TPA+ (>10 micromol/l) concentration-dependently reduced the phenylephrine (1 micromol/l)-, U46619 (30 nmol/l)-, endothelin I (10 nmol/l)- and high K+ (60 mmol/l)-induced sustained tension with respective IC50 values of 53. 7 +/- 9.5, 31.9 +/- 5.3, 30.9 +/- 3.4 and 20.9 +/- 2.8 micromol/l. The present results indicate that TPA+ at low concentrations could contract the arterial smooth muscle probably through promoting Ca2+ influx. At higher concentrations (>20 micromol/l), TPA+ relaxes arterial smooth muscle probably through inhibition of both nifedipine-sensitive Ca+ channels and internal Ca2+ release. TPA+, unlike other quaternary ammonium ions, could therefore act at multiple sites in arterial smooth muscle.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

The involvement of CD80 and CD86 costimulatory molecules in the induction of eosinophilia in mice infected with Nippostrongylus brasiliensis.

The costimulatory signal provided by the interaction between CD28 and its ligands, CD80 and CD86, is critical for T cell activation. The requirement of CD80 and CD86 in T cell activation for eosinophilia and IgE production was examined in mice infected with the nematode parasite Nippostrongylus brasiliensis. Combined treatment with anti-CD80 and anti-CD86 suppressed eosinophilia in the blood and the small intestine and suppressed IgE production. However, administration of either anti-CD80 or anti-CD86 alone had little effect on eosinophilia and on the elevation of IgE levels. These results suggest that CD80 and CD86 costimulation is required and either CD80 or CD86 can provide a sufficient costimulatory signal for induction of eosinophilia in mice infected with N. brasiliensis.

Animals↗

Ischemic stroke is associated with a systemic increase of blood mononuclear cells expressing interleukin-8 mRNA.

BACKGROUND AND PURPOSE: Ischemic brain injury secondary to an arterial occlusion is characterized by acute local inflammation. Blood polymorphonuclear leukocytes (PMNL), primarily neutrophils, adhere to endothelial cells and rapidly invade the injured brain after the arterial occlusion. This neutrophilic invasion might correlate with the production of certain chemoattractants by blood mononuclear cells (MNC). We evaluated mRNA expression of the CXC chemokine interleukin (IL)-8, and the CC chemokines monocyte chemoattractant protein-1, macrophage inflammatory protein (MIP)-1alpha, and MIP-1beta in blood MNC from patients with ischemic stroke. METHODS: Peripheral blood was obtained at 8 AM on days 1 to 7 (mean, day 3) after onset of symptoms. In situ hybridization with radiolabeled synthetic oligonucleotide probes for the chemokines was adopted to measure chemokine mRNA expression in MNC. An enzyme-linked immunosorbent assay for IL-8 was used to measure IL-8 levels in plasma. RESULTS: Most patients with ischemic stroke had high numbers of IL-8 mRNA expressing blood MNC, regardless of the time interval between onset of clinical symptoms and examination. There was a marked difference between patients with ischemic stroke and healthy subjects (median, 6228 versus 885 positive cells per 10(5) MNC; P<.0001). IL-8 levels in plasma correlated positively to IL-8 mRNA expression in examined patients (n=7) with ischemic stroke (r=.78, P<.05). In contrast, mRNA expression for the CC chemokines showed no significant difference between patients with ischemic stroke and healthy control subjects. CONCLUSIONS: This study demonstrated a systemic increase of IL-8 mRNA expressing MNC and IL-8 levels in plasma from patients with ischemic stroke, suggesting that IL-8 could be involved in recruiting blood PMNL to the sites of cerebral ischemia.

Aged↗

Phase II trial of paclitaxel, fluorouracil, and cisplatin in patients with advanced carcinoma of the esophagus.

PURPOSE: We have previously identified paclitaxel as an active single agent in the treatment of esophageal cancer. We performed a phase II trial of paclitaxel in combination with cisplatin and fluorouracil (5-FU), conventionally used chemotherapy for esophageal cancer. The antitumor response, toxicity, and survival of patients treated with the three-drug regimen were evaluated. PATIENTS AND METHODS: Sixty-one patients with advanced, surgically unresectable, or metastatic squamous cell or adenocarcinoma of the esophagus were treated. No prior chemotherapy was allowed. Thirty patients had adenocarcinoma and 31 patients had squamous cell carcinoma. The majority (47 patients; 77%) had metastatic disease and 14 patients (23%) had an unresectable primary or locally recurrent tumor. Patients received paclitaxel 175 mg/m2 by 3-hour infusion day 1; cisplatin 20 mg/m2 daily days 1 through 5, and 5-FU by continuous infusion at a dose of 1,000 mg/m2 daily days 1 through 5. Because of toxicity observed in the first 10 patients treated, the starting dose of 5-FU was subsequently reduced to 750 mg/m2 daily in the remaining patients. A planned attenuation of cisplatin to 15 mg/m2 daily was made after the first three cycles. Granulocyte colony-stimulating factor (G-CSF) was not routinely administered unless the patient had an episode of febrile neutropenia or prolonged grade 4 neutropenia. Treatment was recycled every 28 days. RESULTS: Sixty-one patients completed a median of five cycles, and 60 patients were assessable for response. Major responses were seen in 29 patients (48%; 95% confidence intervals, 35 to 61), which included seven complete responses (12%). Comparable response rates were seen for patients with adenocarcinoma (46%) and those with squamous carcinoma (50%), and for patients with metastatic disease (22 of 46 patients; 48%) and those with locally advanced disease (seven of 14 patients; 50%). A significantly higher complete response rate was observed in patients with squamous carcinoma (20%) compared with those with adenocarcinoma (3%; chi2 P=.04). The median duration of response was 5.7 months (range, 1 to 18.6 months). Median survival was 10.8 months (range, 1.5 to 25 months). Toxicity was severe but manageable with dose attenuation, and included 18% of patients with grade 3 neurologic toxicity. Twenty-eight patients (46%) required a dose attenuation for toxicity, and 42 of 275 treatment cycles (15%) required a dose attenuation. Twenty-nine patients (48%) required hospitalization for toxicity, which included 11 patients for neutropenic fever (18%). There were no treatment-related deaths. CONCLUSION: The combination of paclitaxel, cisplatin, and 5-FU has substantial antitumor activity in metastatic esophageal carcinoma, with a remarkable complete response rate noted in patients with squamous carcinoma. Paclitaxel is an important new agent in the treatment of esophageal carcinoma, and further evaluation of this agent in combination chemotherapy is warranted. Given the toxicity associated with the current regimen, the optimal dose and schedule of paclitaxel in combination chemotherapy remain to be established.

Adenocarcinoma↗

Urinary excretion of D-serine in human: comparison of different ages and species.

The urinary excretion of D-serine (D-Ser) in human, rat and dog of various ages was studied. Great amounts of D-Ser were consistently excreted in human urine throughout life. No age-dependent changes were observed in urinary D-Ser/total-Ser ratios from the newborn to the aged. D-Ser/creatinine ratios in adult human urine were found to be relatively constant in individuals. The constant excretion of D-Ser in human urine was confirmed by analyzing the consecutive 24 h urine of three volunteers. High concentrations of D-Ser and D-alanine (D-Ala) were found in adult dog urine. The urinary D-Ser concentration was high in young rats at unweaned and weaned periods, and then declined with increasing age. In contrast, the urinary D-Ala concentration was very low in suckling rats, and increased rapidly after the weaned state and then declined with increasing age. The species- and age-related excretion of D-Ser in mammalian urine is considered to be due to the differences in the renal handing of D-Ser, because plasma D-Ser concentrations among the groups were not so different. Although free D-Ser has been detected in animal foods and human colostrum, the amount is insufficient to explain the concentration of D-Ser found in urine. These results indicate that urinary D-Ser in mammals may be mainly of endogenous origin.

Adult↗

Cytochrome-P450-dependent biotransformation of xenobiotics in human and rodent embryonic tissues.

Profound species differences and developmental stage differences as well as a lack of solid data prevent broad, sweeping generalizations in terms of statements that can be made concerning the prenatal expression of individual P450 isoforms. It is clear, however, that several of such isoforms are expressed at levels that can be toxicologically significant. At present, the greatest interest appears to be in P450s 1A1, 1B1, 2E1, and 3A7, each of which has been reported to be expressed at toxicologically significant levels or at least at potentially toxicologically significant levels during organogenesis. Reports of the expression of other P450 isoforms at later stages of gestation also have appeared in the recent literature.

Abnormalities, Drug-Induced↗

Phase II trial of docetaxel (Taxotere) for untreated advanced colorectal carcinoma.

The antimicrotubule agent docetaxel (Taxotere), a semisynthetic taxoid, has demonstrated antitumor activity against colorectal cancer cell lines in vitro, and in murine tumor models. We sought to characterize its activity in a group of previously untreated patients with colorectal carcinoma. Eighteen previously untreated patients with advanced, measurable colorectal carcinoma were treated with a 60-min intravenous infusion of docetaxel with a dose of 100 mg/m2 administered every 21 days. Routine premedication with diphenhydramine was given. Patients were required to have normal organ function and a Karnofsky performance status (KPS) > or = 60%. No complete response (CR) or partial responses (PR) were observed. Median survival was 13 months, despite a median time to progression of only 1.3 months. Neutropenia was the most common dose-limiting toxicity, resulting in 5 episodes of febrile neutropenia requiring hospitalization and intravenous antibiotics. One patient experienced a grade 4 hypersensitivity reaction (HSR) requiring treatment termination. No toxic deaths occurred. Despite encouraging preclinical data, docetaxel is an inactive drug in advanced colorectal cancer when given in the dose and on the schedule examined in the present study, and has significant, although reversible, toxicities.

Adult↗

[Study on the cost-effectiveness of therapeutic scheme of acute bacillary dysentery].

A prospective study on the casts of acute bacillary dysentery treatment with antibiotics of aminoglycoside and the 3rd generation of cephalosporin, along with drug sensitive test in vitro was carried out. The results showed that the clinical therapeutic effects and the sensitive rates to drug in vitro between the two kinds of antibiotics were not statistically different (P > 0.05), but the costs of treatment with these two methods were significantly different. The therapeutic costs were calculated in Ren Ming Bi per day per kilogram body weight. The average therapeutic cost with the 3rd generation of cephalosporin was 44.85 times as that with aminoglycoside. The highest cost by Fortum was 364 times Higher than by Gentamycin. Through cost analysis, conclusion was drawn that the 3rd generation of cephalosporin should not be taken as first choice to treat a acute bacillary dysentery.

Adolescent↗

Study on the transmission threshold value of bancroftian filariasis.

OBJECTIVE: To elucidate the transmission dynamic and epidemic trend of bancroftian filariasis occurred under the condition with no control measure taken 5 years after elimination of filariasis. METHODS: A 10-year longitudinal observation (from 1984 to 1994) was made in Huayuan Village in Shengli Township of Tancheng County, which used to be a high bancroftian filariasis-endemic area in southern part of Shandong Province. RESULTS: The microfilarial rate decreased from 0.56% before the study to 0.12% after the study and 8 out of the 9 previous microfilaria-positive cases became negative gradually. During the study period, 6 new microfilaremia cases were detected, 5 of which became negative naturally within 3 to 4 years. Eighty-eight point eight nine per cent of the detected patients with microfilaremia converted into IgG4-negative after 10 years. The natural infective rate of vectors decreased year by year and became zero by the tenth year of the study, the annual transmission potency decreased also from 3.47 to zero by the tenth year. CONCLUSIONS: It showed that under the local natural environment the biting rate representing the vector density which was obtained by capture method was from 24.1 to 52.5 person/night among the residents who did not use mosquito nets, and 13.5 to 21 person/night among the residents who used mosquito nets. The microfilarial rate of 0.56% in population with the average microfilarial density of 6.6 to 20.7 capita/60 microliters ear blood of residual microfilaria-positive patients might be considered as the terminal threshold of transmission.

Animals↗

[Effects of different vascular beds on the microstructural components and intimal hyperplasia of autogenous vein grafts in dogs].

In order to investigate the effect of vascular beds on the vascular wall of autogenously grafted vein, femoral veins were reversely placed in between the cut ends of collateral femoral arteries in 11 dogs with atraumatic technique. The grafted veins were covered with vivid muscle or skin respectively after being assured to be patent, and investigated by histomorphologic method and computerized image analysis technique at postoperative intervals of 1 week, 4 weeks and 16 weeks. The results showed that: 1. One graft developed pseudoaneurysm at 1 week, and two grafts were occulded in skin-covered group, whereas, no complications occurred in muscle-covered group. 2. Intimal thickening of grafts in skin-covered group was much more obvious than that in the muscle-covered group (P < 0.05). 3. The relative contents of microstructural components of the graft wall showed no significant difference quantitatively between the two groups. So, the conclusion was: 1. Subcutaneous transplantation appeared to be a potential causative factor in inducing short-term excessive dilatation and long-term intimal hyperplasia of vein graft. 2. Muscular covering is of priority in blood vessel graft.

Animals↗

[Observation of cicatricial fibroblasts in culture and its biological properties].

In order to study the biological properties of fibroblasts isolated from different tissues. The fibroblasts from normal skin, hypertrophic scar and keloid were cultured, respectively, in vitro, and their morphologies and growth kinetics were compared. The results revealed that although fibroblasts in keloid were irregularly arranged, crisscross and overlapping with loss of polarization, there was no significant difference in the 3 groups so far the cellular morphology of fibroblast itself, cellular growth curve, cellular mitotic index, cloning efficiency and DNA content provided those cultures were in the same cellular density and culture conditions. It was concluded that fibroblasts isolated from culture of normal skin, hypertrophic scar and keloid in vitro showed no significant difference in morphology and growth kinetics, on the contrary, their biological behaviors were quite similar.

Adolescent↗

Inhibitory effects of cyproheptadine on pituitary-thyroid axis and pancreatic beta cells in rats.

AIM: To study the influences of cyproheptadine (Cyp) on the endocrine functions of pituitary-thyroid axis and pancreatic beta cells in rats. METHODS: The effects of Cyp on functions of pituitary-thyroid axis and pancreatic beta cells were observed by radioimmunoassay, biochemical analysis, and electron microscope. RESULTS: Cyp 2.3 mg.kg-1 ig for 10 d decreased serum thyroid stimulating hormone (TSH) from control groups (5.3 +/- 0.9) to (4.2 +/- 0.9) mU.L-1 and insulin levels from (64 +/- 8) to (50 +/- 9) kIU.L-1 (P < 0.05 and 0.01). Cyp 4.6 mg.kg-1 decreased serum TSH (3.8 +/- 0.5) mU.L-1, T3 (1.2 +/- 0.2) mmol.L-1, T4 (62 +/- 7) mmol.L-1, and insulin levels (42 +/- 8) kIU.L-1 decreased (P < 0.05 or 0.01). The retrograde changes of ultrastructure of pituitary TSH cells and pancreatic beta cells. CONCLUSION: Cyp has an inhibiting action on endocrine functions of pituitary-thyroid axis and pancreatic beta cells in rats.

Animals↗

Radix Salviae miltiorrhizae protects rat hippocampal neuron in culture from anoxic damage.

Radix Salviae Miltiorrhizae (RSM), a well-known traditional Chinese medicinal herb, has been used to improve blood circulation and resolve blood stasis. We have previously found that RSM has neuroprotective effect on ischemia and/or ischemia-reperfusion rats. The purpose of this study was to obtain further information on the mechanism of the RSM-induced neuroprotection and to examine the neuroprotective effect on neurons exposed to anoxia. The effect of RSM on anoxic damage in cultured hippocampal neurons of neonatal rat was investigated by using morphological changes and heat shock protein 70 kD (HSP70) expression as indicators. RSM given 0.5 h before 2 h-anoxia followed by 48 hours reoxygenation could significantly increase survival rate of hippocampal neurons and number of HSP70 positive cells. The results suggest that RSM has a direct neuroprotective effects on anoxic damage in hippocampal neurons.

Animals↗