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Biomedical subjects

W Liang

Publications and source records attributed to W Liang.

At least 37 records · Page 2Linked to original sources
PubMed2001

[The effect of IFN-alpha 2b-thymus peptides combined therapy in chronic hepatitis B].

OBJECTIVE: To determine the effects of IFN-alpha 2b associated with thymus peptides in treatment of chronic hepatitis B. METHODS: A total of 52 individuals with chronic hepatitis B received IFN-alpha 2b(5 x 10(6) IU/ml qod) for 6 months and thymus peptides(20 mg qod) for 3 months. 50 patients received SMMC or other medicine such as WuWeizi, CuiPenCao served as control. There were no differences between two groups in sex, age, duration and seriousness of the disease. RESULTS: The primary outcome measure for efficacy was the percentage of HBV DNA/HBeAg negativity after 6 months therapy. Rate of HBV DNA negativity was 75% and that of HBeAg was 73.1%, the inhibitory activity of IFN-alpha 2b against HBV was significantly higher than that of the control. Except transient fever, leukopenia and thrombocytopenia appearing at the beginning of the therapy, no serious adverse events were observed. CONCLUSION: Potent inhibitory activity against HBV of IFN-alpha 2b is suggested and much works need to be done to improve the long-term effect of the therapy.

Adjuvants, Immunologic↗
PubMed2001

[The electric pulse caused pore in the skin observed by fluorescence microscopy].

The objective of this study was to enunciate the difference in skin morphological changes between iontophroresis and electroporation for transdermal drug delivery (TDD). Fluorescence microscope was employed to observe the skin structure of human and snake in passive diffusion (control); iontophoresis was performed using direct current(0.5 mA/cm2) and electroporation was performed using intensive 380 V, pulse rate 4 ppm, pulse duration 5.5 ms, pulse number 100 and electric capacity 22 microF. Fluorescein was FITC. The results showed that for human skin in the passive, these were a few highlight fluorescent blots with scale of 15-30 microns and rough edge, but the edge of the blots became smooth and the scale did not change in the iontophoresis; when the scale of the blots was extended to 80-90 microns, the edge was smooth. For the snakes shin, the highlight blots were not sighted in the passive and iontophoresis, but they were found to be 25-30 microns in the electroporation. These data demonstrate that electric pulse can cause pore in the skin, thus creating a new route for drug permeation through skin.

Administration, Cutaneous↗
PubMed2001

[Soil biota and its role in soil ecology].

Soil organisms alter soil physical, chemical and biological properties in different ways. The composition and structure of biotic communities at one hierarchical level can influence the spatial heterogeneity of resource at other hierarchical levels, and the latter is supported by a number of biologically relevant spheres-functional domains in soil. In this paper, the role of soil biota in soil ecosystem processes was assessed, and the relationship between soil biodiversity and ecosystem function was presented. Soil ecosystem responses to global change were also discussed.

Ecosystem↗
PubMed2001

[Function of vascular endothelial growth factor in ovarian hyperstimulation syndrome].

OBJECTIVE: To evaluate the function of vascular endothelial growth factor (VEGF) and other clinical indexes to forcast ovarian hyperstimulation syndrome (OHSS). METHOD: Collecting the serum and follicular fluid (FF) of 42 cases in the in vitro fertilization and embryo transfer (IVF-ET) cycles and then analysis the relationship of the clinical and detected indexes between the OHSS (10 cases) and the non-OHSS (32 cases). RESULTS: The concentration of VEGF in FF, E2 on the day of human chorionic gonadotropin (hCG) injection, basal luteinizing hormone (LH) and the number of ovum retried much higher in the OHSS than in the non-OHSS. CONCLUSIONS: The concentration of VEGF in FF of OHSS cases is higher than that of controls, supporting the role of VEGF as a mediator of OHSS. Therefore VEGF in FF is a forcast index of OHSS.

Dinoprostone↗
PubMed2000

Enhanced transdermal delivery of tetracaine by electroporation.

The effect of electroporation on the transport of tetracaine through skin in vitro was studied using side-by-side compartment diffusion cells method. After achieving steady state by passive diffusion, fluxes of tetracaine achieved with passive diffusion, electroporative pulse and iontophoresis were compared. Electroporation (square-wave pulse, voltage 130 V, pulse time 0.4 s, pulse frequency 40 pulses min(-1)) or iontophoresis (0.2.mA cm(-2), lasting for 4 h) increased the transport of tetracaine through skin. The flux of tetracaine at 0.25 h after electroporation (pulse number 400) was 54.6+/-6.0 microg.cm(-2).h(-1), that after iontophoresis was 17.4+/-5.8 microg.cm(-2).h(-1) and that after passive diffusion was 8.2+/-0.5 microg.cm(-2).h(-1). In addition, the fluxes of tetracaine increased with the increasing of pulse number. From these results, it is clear that electroporation is effective in enhancing transdermal delivery of tetracaine and its function is better than iontophoresis.

Administration, Cutaneous↗
PubMed2000

Mutational analysis of phosphorylation sites in the Dictyostelium myosin II tail: disruption of myosin function by a single charge change.

The dynamic assembly/disassembly of non-muscle myosin II filaments is critical for the regulation of enzymatic activities and localization. Phosphorylation of three threonines, 1823, 1833 and 2029, in the tail of Dictyostelium discoideum myosin II has been implicated in control of myosin filament assembly. By systematically replacing the three threonines to aspartates, mimicking a phosphorylated residue, we found that position 1823 is the most critical one for the regulation of myosin filament formation and in vivo function. Surprisingly, a single charge change is able to perturb filament formation and in vivo function of myosin II.

Animals↗
PubMed2000

Experimental infection of nonenveloped DNA virus (TTV) in rhesus monkey.

Virus fragments homologous to TTV were detected previously from an enterically transmitted outbreak of non-A-E hepatitis [Luo et al., 1999]. To test the susceptibility of the Rhesus monkey to this virus and to establish its transmission routes, 6 Rhesus monkeys were inoculated, 3 orally and another 3 intravenously. The inoculum was prepared by extracting and filtering feces collected from a patient during the incubation period identified in the described outbreak. A second group of 3 monkeys was used for the passage study. The feces and blood samples were collected for detection of the virus by polymerase chain reaction (PCR). Four animals were subjected to liver biopsies and bile aspiration by open surgery for in situ virus detection. Viremia occurred in 4-7 days after intravenous and 7-10 days after oral inoculation. The virus was excreted in feces a few days after oral infection and simultaneously with viremia after intravenous inoculation. The virus was also detected in bile during the viremic phase. There was a prolonged carrier state with persistent viremia and virus excretion in feces for more than 6 months. Serum transaminase levels were not raised during the infection. The virus was present in both the cytoplasm and nuclei of hepatocytes, but no significant pathology was found. Therefore, the Rhesus monkey is susceptible to TT virus infection, but the virus seems nonpathogenic. Infection of the liver may be established either by oral or parenteral inoculation. The virus may be released from liver into the blood or via bile into feces, so it may be transmitted by both blood and fecal routes.

Alanine Transaminase↗
PubMed2000

The work by the developing primary care team in China: a survey in two cities.

BACKGROUND: China is in the process of converting its existing primary care resources into general practice. The infrastructure is different from that of many other countries. OBJECTIVES: We surveyed patients' reasons for encounter (RFE) and the health providers' diagnoses in the general practice clinics of two large northern cities in order to assess the nature of the work of these practices. METHOD: Practices whose staff had a short course of training in the theory and practice of the International Classification of Primary Care (ICPC) were recruited to document the RFE and diagnoses of patient encounters in two separate winter weeks. RESULTS: The practices dealt mainly with chronic illness in older patients. Hypertension-related problems were the most frequent diagnoses, followed by upper respiratory tract infection. Patients also consulted very frequently for dizziness. Overall, there was good agreement between RFE and diagnosis in some organ systems. CONCLUSION: In their present form, the Chinese practices surveyed were delivering the full range of general practice care to a self-selected age group of patients. The ICPC was very useful for monitoring the work of general practice from the perspective of both the patients and the providers.

Adolescent↗
PubMed2000

Expression of the porcine beta2-adrenergic receptor in Chinese hamster ovary cells.

The gene for the porcine beta2-adrenergic receptor (pbeta2AR) was transfected into Chinese hamster ovary (CHO) cells for expression. Fourteen stable cell lines were obtained and exhibited receptor densities ranging from 12 to 2,371 fmol/mg membrane protein. The receptor density was not correlated with estimates of gene copy number obtained by Southern hybridization. The pbeta2AR in CHO cells exhibited saturable binding of [125I]CYP (Kd = 14.5 pM) and stereospecificity for (-)- and (+)-isoproterenol. The relative affinities for (-)-isoproterenol (ISO), (-)-epinephrine (EPI), and (-)-norepinephrine (NEPI) were ISO > EPI > NEPI, which are characteristic of beta2AR. The affinity values for these ligands were similar to those in other species. Binding of ISO, EPI, and NE revealed two affinity states of the betaAR; the high-affinity state was eliminated by adding Gpp(NH)p, a nonhydrolyzable GTP analogue. Binding of the antagonist propranolol modeled to only one affinity state, and Gpp(NH)p did not affect binding. Multiple affinity states are characteristic of agonist-induced coupling of betaAR with G-proteins, and the data suggest that the cloned pbetaAR is functionally competent. Data confirm that the pbeta2AR is the pig version of beta2AR. Stable CHO cell lines will be useful for characterization of pbeta2AR and screening and designing potential drugs that may be used to enhance pig production.

Animals↗
PubMed2000

[Effects of bushen yizhi recipe on somatostatin-like immunopositive and somatostatin messenger ribonucleic acid expressed-positive neurons in Alzheimer's disease model rats].

OBJECTIVE: To observe the effect of Bushen Yizhi Recipe (BYD) on somatostatin-like (SS-like) immuno-reactivity and SS mRNA expressed-positive neurons in Alzheimer disease (AD) model rats induced by D-galactose intraperitoneal and ibotenic acid (IBO) intracerebral injection. METHODS: Fifteen months Wistar rats were randomly divided into 4 groups: normal control; AD model control induced by D-galactose intraperitoneal injection and lesion of basal nucleus of Meynert with IBO; Huperzine A (Hup-A) treated group and BYD treated group fed with Hup-A or BYD respectively. The SS-like immunoreactivity and SS mRNA expressed-positive neurons in parietal lobe, hippocampal CA1 field and hilus of the dentate gyrus in the brains of rats, which were detected with immunohistochemistry and DIG-labelling cRNA-probe in situ hybridization. RESULTS: Counts and integrations of optic density of SS-like immuno-reactivity and SS-mRNA expressed neurons in parietal lobe, hippocampal CA1 field and hilus of the dentate gyrus in BYD treated group increased compared with AD model rats. CONCLUSION: BYD might protect the SS-ergic system against impairment of D-galactose and IBO in the brains of the AD model rats.

Alzheimer Disease↗
PubMed2000

[Studies on the supercritical CO2 fluid extraction and separation of psoralen, isopsoralen and fatty oils from Psoralea corylifolia].

Opimum extraction conditions were studied by supercritical carbon dioxide fluid extraction technology and orthogonal tests. Crystal of psoralen can be achieved directly from the extractives. Magnified experiments were carried out. The chemical constituents of fatty oils were analyzed by GC-MS. The result shows that the optimum conditions are: extraction pressure 27 MPa, extraction temperature 70 degrees C; seperation pressure 9 MPa, seperation temperature 60 degrees C. Six components such as oleic acid, linoleic acid etc. were identified in the fatty oils.

Carbon Dioxide↗
PubMed1999

A structural model for phosphorylation control of Dictyostelium myosin II thick filament assembly.

Myosin II thick filament assembly in Dictyostelium is regulated by phosphorylation at three threonines in the tail region of the molecule. Converting these three threonines to aspartates (3 x Asp myosin II), which mimics the phosphorylated state, inhibits filament assembly in vitro, and 3 x Asp myosin II fails to rescue myosin II-null phenotypes. Here we report a suppressor screen of Dictyostelium myosin II-null cells containing 3 x Asp myosin II, which reveals a 21-kD region in the tail that is critical for the phosphorylation control. These data, combined with new structural evidence from electron microscopy and sequence analyses, provide evidence that thick filament assembly control involves the folding of myosin II into a bent monomer, which is unable to incorporate into thick filaments. The data are consistent with a structural model for the bent monomer in which two specific regions of the tail interact to form an antiparallel tetrameric coiled-coil structure.

Actin Cytoskeleton↗
PubMed1999

A population-based study of age and gender differences in patterns of health-related behaviors.

PURPOSE: Most research on preventive health behaviors has focused on individual rather than groups of behaviors. This study examined interrelationships among multiple preventive health behaviors in different age and gender groups. METHODS: From 1990 to 1992, Maryland residents were surveyed by telephone through the Behavioral Risk Factor Surveillance System. The study sample of 4455 was divided into 8 groups based on age (18-24, 25-39, 40-54, and 55+) and gender. Correlation and oblique rotated factor analyses were used to examine patterns of 8 to 11 preventive health behaviors in each age-gender group. RESULTS: Medical checkup and cholesterol test formed one behavioral cluster in the four male age groups. Breast and cervical cancer screening (mammogram, clinical breast examination [CBE], and Pap Smear) did not form one cluster until age 55 or older; Pap smear, CBE formed one cluster for women of all ages. Risk-taking behaviors were only prominent in the youngest age group: Seatbelt non-use, smoking, and drinking formed one cluster in younger males, and drinking and driving after drinking clustered in younger females. CONCLUSION: Screening and risk-taking behaviors form distinct groups, and behavioral patterns differ by age and gender. Public health programs should consider multi-behavioral approaches, and be sensitive to the gender and age of the target population.

Adolescent↗
PubMed1999

The relationship between the c-jun mRNA expression and apoptosis of neurons in rat brain following perinatal ischemic-hypoxia.

OBJECTIVE: To investigate the relationship between c-jun mRNA and apoptosis of neurons following perinatal ischemic-hypoxia. METHODS: We set up a fetal rat model of perinatal ischemic-hypoxia by ligating unilateral uterine horn vessel of pregnant Wistar rats (21-day gestation). The contralateral horn vessel was not ligated and the fetuses in these uteri served as controls. Rat pups were delivered by cesarean section at the end of ischemic hypoxic insult and then the rats' brain tissues were collected in different points of time. In situ hybridization and TUNEL methods were used to detect the c-jun mRNA expression and neural cells apoptosis separately. RESULTS: The expression of c-jun mRNA in brain tissues began at 15 minutes, reached the first peak at 1-2 hours after ischemic-hypoxic insult and reduced gradually after 4 hours and the second peak at 24th hour after insult, gradually disappeared till 72nd hour. There were very low c-jun mRNA expression of hippocampus in the control group 24 h after birth. Meanwhile, we observed that the apoptosis of neuronal cells in cerebral cortex was much more than that in the control group. CONCLUSION: The increases of immediate early gene c-jun expression and the cell apoptosis could be induced by perinatal ischemic-hypoxia. The higher expression of c-jun mRNA might induce the transcription of its target gene, especially, so called "death related genes", which would be a promoter for cell apoptosis.

Animals↗
PubMed1999

[A comparative study of different neuromuscular pedicle embedded in posterior cricoarytenoid muscle].

OBJECTIVE: To compare the results and effect of different neuromuscular pedicle (NMP) embedded in posterior cricoarytenoid muscle. METHOD: In 22 dogs, combined vocal cord paralysis models were made. The first group (10 dogs) were embedded by sternohyoid muscle pedicle of ansa cervicalis, the second (10 dogs), accessory sternocleidomastoid neuromuscular pedicle, the third (2 dogs), control group. RESULT: Evaluation was possible in 19 dogs. Reinnervation of the left posterior cricoarytenoid muscle occurred in 17 dogs following NMP. Return of spontaneous abduction in the operated side with NMP was noted after 4 months postoperatively. There was little difference between the two NMP groups. CONCLUSION: NMP was successful to reinnervate the posterior cricoarytenoid muscle.

Accessory Nerve↗
PubMed1999

[Study of cytotoxicity of bioprosthetic heart valve material and its store solution].

This study compared the cytotoxicities of bioprosthetic heart valve materials crosslinked by glutaraldehyde, stored in 4% formaldehyde or Hank's solution. Human embryonic pulmonary fibroblasts or L-929 cell culture in vitro were used. Cell proliferative inhibition index(CP II) was calculated for bioprosthetic heart valve materials using different store methods in different rinse periods(before, 10 days, 20 days, 30 days). The results demonstrate: (1) bioprosthetic heart valve materials stored in 4% formaldehyde or in Hank's solution both have significant cytotoxicity, and the longer the rinse time continues, the lower the cytotoxicity declines; (2) HEL cell is more sensitive than L-929 cell in detecting the cytotoxicity of toxic biomaterials but for weak toxic biomaterials the two cell lines are not significanth different; (3) formatldehyde solution increases the cytotoxicity of biomaterials stored in it, but the enhanced cytotoxicity can be easily relieved by rinse. The authors conclude that bioprosthetic heart valve materials have long term significant cytotoxicity and the biomaterial cytotoxicity test using human fibroblasts is more sensitive and precise than other tests.

Animals↗