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Biomedical subjects

X Huang

Publications and source records attributed to X Huang.

At least 433 records · Page 24Linked to original sources
PubMed1998

[Angiotension I converting enzyme gene polymorphism in Chinese patients with obstructive sleep apnea syndrome].

OBJECTIVE: To investigate the relationship of an insertion/deletion (I/D) polymorphism of the angiotension-converting enzyme (ACE) gene to obstructive sleep apnea syndrome (OSAS). METHOD: Genomic DNA was extracted from blood samples and amplified by polymerase chain reaction (PCR). PCR primers were flanking the polymorphic region in intron 16 of the ACE gene. RESULT: The distribution of the DD, ID, and II ACE genotypes was 16%, 52%, and 32% in the control subjects and 0%, 56%, and 44% in OSAS patients, respectively. The estimated frequencies of the insertion allele and the deletion allele were 58%, 42% in the control subjects and 72%, 28% in OSAS patients, respectively. The differences were statistically significant(P < 0.05). The OSAS patients with I/I genotype had significantly longer apnea time (P < 0.05), lower minimum SaO2(P < 0.05) and more severe AHI (P < 0.05) than did the OSAS patients with I/D genotype. CONCLUSION: These results indicate that the II genotype and I allele might be a risk factor for OSAS in Chinese.

Alleles↗
PubMed1998

[Treatment of 34 cases of chronic aplastic anemia using prepared Rehmannia polysaccharide associated with stanozolol].

OBJECTIVE: To investigate the effect and side effect of prepared Rehmannia polysaccharide (PRP) associated with stanozolol in treating chronic aplastic anemia (CAA). METHODS: Thirty-four cases of CAA were treated by PRP liquid associated with stanozolol, course of 3 week treatment, and control group (17 cases of CAA) was treated by stanozolol alone. RESULTS: Effective rate was 85.3% in treatment group, and that of control group was 58.8%, there was significant difference between them (P < 0.05). Symptom remission of treatment group was earlier than that of control group, symptom scoring between two groups, the difference was highly significant (P < 0.01). Blood cell had a distinct elevation after treatment with PRP associated with stanozolol, and had a significant difference in comparing with pre-treatment in treatment group (P < 0.01). Side effect of PRP was not found during treatment of CAA. CONCLUSIONS: PRP associated with stanozolol to treat CAA has an additional effect, it can accelerate symptom remission without any additional side effect.

Adolescent↗
PubMed1998

[Clinical study on preventing and treating chemotherapy induced nausea and vomiting using supplemented Inula-Ochrae Decoction].

OBJECTIVE: To observe supplemented Inula-Ochrae Decoction (SIOD) in preventing and treating nausea and vomiting induced by chemotherapy for patients with malignant tumour. METHODS: Seventy-two patients were divided into two groups, the patients in test group took SIOD and in control group using ondensetron, and the efficacy of SIOD in preventing and treating chemotherapy induced nausea and vomiting were studied prospectively with self-intersection approach. RESULTS: The effective rate of treating vomiting due to chemotherapy with DDP and without DDP in the test group was 92.7% and 93.5% respectively, and was higher than that in the control group 87.8% and 87.1%, the difference was insignificant statistically (P > 0.05). CONCLUSIONS: The prescription SIOD could prevent and treat effectively chemotherapy induced nausea and vomiting without any toxic and side effects, and is inexpensive with high efficacy for clinical use.

Adolescent↗
PubMed1998

[Chemical constituents of Tetrastigma hemsleyanum Diels. et Gilg].

OBJECTIVE: To investigate the chemical constituents of Tetrastigma hemsleyanum. METHOD: Compounds were separated by rechromatography on silica gel from the chloroform solubles of its ethanol extracts, and the structures were determined by spectral analysis and chemical evidence. RESULT: Three compounds were isolated and elucidated as 6'-O-benzoyldaucosterol, daucosterol and beta-sitosterol. CONCLUSION: All the three compounds were isolated from this plant for the first time, of which 6'-O-benzoyldaucosterol is a new natural product.

Drugs, Chinese Herbal↗
PubMed1998

[Determination and significance of catecholamines in aqueous humor, plasma and 24 hour urine of patients with acute angle-closure glaucoma].

OBJECTIVE: To study the functional state of ocular and systemic sympathetic nervous system and the effects of its related neurohumoral factor, catecholamines (CA), on intraocular pressure (IOP) in patients with acute angle-closure glaucoma (AACG). METHODS: The levels of CA in the aqueous humor, plasma and the total amount of CA in 24 hour urine of cases with AACG during attack stage were determined with fluorometry, and the results were compared to that of patients with senile cataract and normal adults. RESULTS: The CA levels within aqueous humor and plasma and in 24 hour urine of the patients with AACG during attack stage were elevated obviously as compared with that of the control subjects (P < 0.001), and positively correlated with the level of IOP. CONCLUSION: During attack stage of AACG, the ocular sympathetic nervous system is highly excited and a large amount of CA is released into the aqueous humor, in the meantime the systemic sympathetic nervous system is also excited and CA is released into the blood circulation, which may play a certain role in the regulation of IOP. Possibly, CA is an important supplemental factor within the attack stage of AACG.

Acute Disease↗
PubMed1998

[Immunohistochemical studies on wholemounts of the cornea and iris-ciliary body after corneal transplantation].

OBJECTIVE: To study the phenotype of the cells involved in the pathogenesis of allograft rejection after corneal transplantation. METHODS: Wholemounts of the cornea and iris-ciliary body were isolated and prepared from normal rats and those after penetrating corneal transplantation. Immunohistochemical stainings were carried out on these wholemounts using monoclonal antibodies to CD3 (T cell), CD4 [T-helper (Th) cell], CD8 [T-suppressor (Ts) cell], macrophages, dendritic cells, B lymphocytes, major histocompatibility complex (MHC) class II antigen and transforming growth factor-beta (TGF-beta). RESULTS: All the cells mentioned above except B lymphocytes were positive and present in a small number in the peripheral cornea and limbus of normal rats. A massive influx of CD3, CD4, CD8 positive cells, macrophages, dendritic cells, MHC class II and TGF-beta positive cells not only into cornea but also into the iris was observed 7 days after allograft corneal transplantation. Whereas no B cell was found in the allograft. Such a cellular response was not found in the rats in which corneal transplantation with autologous cornea was performed. CONCLUSION: T cells, Th cells, Ts cells, macrophages, dendritic cells, MHC class II positive cells and TGF-beta positive cells are involved in the pathogenesis of corneal allograft transplantation. The involvement of the iris and ciliary body may promote or aggravate the allograft rejection.

Animals↗
PubMed1998

[A study on lens epithelial cell ultrastructure in rhesus monkey cataract].

OBJECTIVE: To investigate the ultrastructure of lens epithelial cells of normal eyes and cataractous eyes in rhesus monkeys. METHODS: Anterior capsules were taken from 4 normal lenses and 4 cataractous lenses of rhesus monkey eyes, and the samples were observed under transmission electron microscope. RESULTS: The ultrastructure of the cataractous lens epithelial cells changed obviously. Mitochondria with disappearance of crista were swollen, and vacuolar. Hollow cell with a single large vacuole in the cytoplasm could be seen. The cytoplasm presented dissolution. Cells were swollen and damaged, even cell membrane disruption could be seen. Karyopyknosis, nuclear deformity, disappearance of perinuclear cistern and nuclear pores could be found. The heterochromatin was concentrated and aggregated at the nuclear periphery. CONCLUSIONS: The ultrastructural changes of the lens epithelial cells in monkey cataractous lens are similar to that in human cataractous lens. Rhesus monkey cataract may be a suitable experimental model to investigate the formation of human cataract.

Animals↗
PubMed1998

[Sulfation of polysaccharides isolated from Indocalamus tesselatus and their anticytopathic effect on human immunodeficiency virus type I].

For preparation of sulfated polysaccharides isolated from bamboo leaves (Indocalamus tesselatus) with chlorosulfonic acid-pyridine, the experimental conditions as the molar ratio of reactants and temperature and time of reaction were discussed. A homogeneous sulfation method with good yield of more than 80% was obtained and the sufur content was found to be 21.9%. Conformation change in sulfated polysaccharide with changes of intrinsic viscosity, polarimetery and CD spectra were found to be related to the negative charge. The polysaccharide sulfates were shown to have better activity to inhibit cytopathic effect of human immunodeficiency virus(HIV) infection than native polysaccharides. The effective concentration was 10 micrograms.ml-1 while the cytotoxic concentration was 2.5 mg.ml-1.

Antiviral Agents↗
PubMed1998

[Multiple dose pharmacokinetic and bioavailability studies of oral sustained release and conventional formulations of isosorbide-5-mononitrate in healthy volunteers].

The pharmacokinetics of a new sustained release tablets (40 mg, qd) of isosorbide-5-mononitrate (IS-5-MN) was investigated together with a conventional preparation (20 mg, bid) after multiple oral administration in ten healthy human subjects using an open, randomized two-way crossover experimental design. Based on three statistical analyses of the area under the plasma concentration-time curve (AUC), the two tablet formulations are judged to be bioequivalent (P > 0.1), with a relative bioavailability of 108.95% for the IS-5-MN sustained release formulation. Pharmacokinetic data showed that the sustained release formulation reached mean peak plasma levels significantly later and lower minimum plasma concentration (Cmin), compared with the conventional preparation. But no statistically significant difference was found for other pharmacokinetic parameters including peak plasma levels (Cmax), AUC, elimination constant (Ke), elimination half-life (T1/2) and fluctuation index (FI) between the two preparations (P > 0.05).

Adult↗
PubMed1998

[Isolation, detection toxicity and structure of toxin from Beauveria bassiana].

In this experiment, the crude toxin from the metabolite of Beauveria bassiana was isolated and its toxicity was detected. The result shows that indicates toxin has toxicity on larva of Aedesalbopictus obvious. Though it with low toxicity to larva of Heliothis zea when swallowed, but has high toxicity when injected into the blood. For bacteria it only inhibites G+. When it applied to cultured cells of Spodoptera frugiperda sf-21, the regression equation of toxicity is y = 2.03 + 2.39x. The half lethal concentration (LC50) is 0.01751%. 95% believable limit is 0.01517-0.0202%. There are three substances which have similar atomic group when analysed by HPLC and infrared spectrum.

Aedes↗
PubMed1998

[Influence of dextran 40 and dextran 70 on the adhesion of erythrocytes to endothelial cells].

Adopting the flow chamber realtime microrecordation system, we studied the dynamic effects of dextran 40(DX40) and dextran 70(DX70) on the adhesion of erythrocytes to monolayer of cultured human umbilical vein endothelial cells (HUVEC). The results demonstrated that erytherocytes pretreated with DX40 adhered to HUVEC less than the erythrocytes of the control group did, but DX70 increased the number of erythrocytes adhering to HUVEC. The higher the concentration of DX70 was, the more the erythrocytes pretreated with DX70 adhered to HUVEC. When shear stress increased, the decrease rate of the number of erythrocytes (pretreated with DX70) adhering to HUVEC declined with the increase of DX70 concentration. These indicate that DX40 as an expander of blood plasma is better than DX70.

Cell Adhesion↗
PubMed1998

[Effect of eel oil capsule on mice memory].

Step-down test, step-through test and water maze in mice were used to observe the effect of eel oil capsule on mice memory. The results indicated that during the administration period (30 days), the eel oil capsule treating groups with dosages of 0.129, 0.387, and 1.161 g/kg obviously improved the learning and memory abilities. Compared with the control test, the eel oil capsule promoted the memory and smart.

Animals↗
PubMed1998

[Serum soluble interleukin-2 receptor levels in uveitis].

PURPOSE: To investigate the relationship between serum SIL-2R levels and uveitis. METHODS: SIL-2R levels were measured in sera of 64 patients with active uveitis by ELISA assay, 61 healthy subjects as control. RESULTS: Serum SIL-2R levels in the patients with active uveitis were significantly higher than that in the controls, but there were no significant difference among anterior uveitis, intermediate uveitis, Behcet disease and Vogt-Koyanagi-Harada syndrome. After therapy the serum SIL-2R levels were obviously decreased. CONCLUSION: SIL-2R Levels in serum correlate with activity of uveitis.

Adolescent↗
PubMed1998

[Study on colour reaction of iron(II)-thibarbituric acid-nitrite system and its analytical application].

In this paper, the optimum conditions of colour reaction of iron (II)-thibarbituric acid-NO2(-) system, existent state and spectrophotometric characteristies of the complex were studied, and the reaction mechanism discussed. A new spectrophotometric method for the determination of trace iron was established. In a buffer solution of borate/NaOH of pH9.5, iron (II) and thibarbituric acid-NO2(-) react to form a stable blue complex anion, for which the maximum absorbance is at 645nm and the molar absorptivity is 2.66 x 10(4)L x mol(-1) x cm(-1). Beer's law is obeyed in the range of 0-40 microg/25mL for iron (II). The method is simple and rapid, shows satisfactory selectivity and precision and has been applied to determine iron in waters with satisfactory results.

English Abstract↗
PubMed1998

Microtubule contribution to the reflectance of the retinal nerve fiber layer.

PURPOSE: The reflectance of the retinal nerve fiber layer (RNFL) arises from cylindrical light scattering elements distributed throughout its thickness. To determine whether these elements include axonal microtubules, eyecup preparations of the toad Bufo marinus were treated with the microtubule depolymerizing agent colchicine. METHODS: Some eyecups were incubated for various times in different colchicine concentrations and then fixed and prepared for electron microscopy (EM). In other eyecups the reflectance of the RNFL at 440 nm was measured by means of imaging microreflectometry. After a period of baseline measurements, the bathing solution was changed either to one of identical composition (control experiments) or to one containing 10 mM colchicine. Measurements then continued for 2 to 3 hours. RESULTS: Quantitative EM showed that colchicine caused the density of axonal microtubules to decrease by approximately one third in 2 hours. Reflectometry showed, in control experiments, that the RNFL reflectance remained near baseline for the duration of an experiment. In contrast, after changing to colchicine solution, the RNFL reflectance declined to a level 37% to 55% below baseline. CONCLUSIONS: Microtubules made a major contribution to the 440-nm reflectance of the unmyelinated axons of the toad RNFL and could make a similar contribution to the reflectance of human RNFL.

Animals↗
PubMed1998

Enhancement of obliterative airway disease in rat tracheal allografts infected with recombinant rat cytomegalovirus.

BACKGROUND: Cytomegalovirus infection has been identified as a significant risk factor for the development of obliterative bronchiolitis in human lung transplant recipients. This study was designed to assess the influence of rat cytomegalovirus (RCMV) on the pathogenesis and development of obliterative bronchiolitis in an experimental model of obliterative airway disease, which occurs after allogenic heterotopic tracheal transplantation in rodents. METHODS: Sixty Lewis rats were infected intraperitoneally with 10(7) plaque-forming units of recombinant lac-Z-tagged RCMV expressing the gene for beta-galactosidase. Rats were either infected at the time of surgery (acute infection, n = 30) or 56 days before surgery (chronic infection, n = 30). Tracheae from Brown Norway (allograft) or Lewis (isograft) rats were implanted and wrapped in the greater omentum of infected Lewis rats. RCMV infection was verified in different recipient tissues by in vitro plaque-assays and by direct in situ staining for beta-galactosidase activity. The tracheal grafts were harvested on days 7, 14, and 21 after transplantation and stained with hematoxylin-eosin and Masson's trichrome. The peritracheal cellular inflammation was scored visually. The cellular density of the infiltrating cells and the extent of airway obliteration were analyzed by use of computer-digitized morphometry and compared with uninfected allografts as control. RESULTS: Both acute and chronic cytomegalovirus infection produced significantly higher mononuclear cell density values on days 7 and 14 compared with noninfected controls, indicating a more intense immune response in the infected allografts. Tracheal allograft obliteration was also more extensive after acute and, in particular, after chronic cytomegalovirus infection (64% narrowing after 21 days compared with 36% in grafts from noninfected control animals). CONCLUSIONS: Our experimental results provide direct evidence that the tracheal grafts were infected with RCMV and that the development of obliterative airway disease was enhanced in the acutely and chronically infected allografts compared with grafts from noninfected control animals.

Animals↗
PubMed1998

Single and multiple dose pharmacokinetic studies of oral sustained release and non-sustained release formulations of isosorbide-5-mononitrate in healthy volunteers.

The pharmacokinetics of a new sustained release tablet (40 mg, "test") of isosorbide-5-mononitrate (CAS 16051-77-7, IS-5-MN) was investigated together with a reference preparation (20 mg, "reference") after single and multiple oral administration in ten healthy human subjects using an open, randomised two-way crossover experimental design. Based on the statistical evaluation of the area under the plasma concentration-time curve (AUC), the two tablet formulations are judged to be the same with regard to the amount absorbed. Pharmacokinetic data showed that with the test tablet significantly lower and delayed mean peak plasma levels (Cmax) were reached compared with the reference preparation in both single and multiple dose studies. The test formulation also produced lower minimum plasma concentration (Cmin). However, there was no statistically significant difference for other pharmacokinetic parameters, including the elimination rate constant (Kel), the elimination half-life (t1/2) and the peak-trough fluctuation constant (PTF) between the two treatments. It was demonstrated that the new sustained release formulation of isosorbide-5-mononitrate could be useful in clinical practice for the treatment of angina pectoris and congestive heart failure.

Adult↗