Biomedical subjects

Y Wu

Publications and source records attributed to Y Wu.

At least 703 records · Page 39Linked to original sources

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

[Effects of phenylalanine, sucrose and mannitol on the growth and production of taxol, baccatin III and 10-deacetylbaccatin III in suspension cells of Taxus media].

The effects of phenylalanine, sucrose and mannitol on the cell growth and the production of taxol, baccatin III and 10-deacetylbaccatin III in the suspension cells of Taxus media were studied. The results showed that phenylalanine 1.0 mmol.L-1 or 2.0 mmol.L-1 initially added into the medium, and sucrose 73.0 mmol.L-1 and mannitol 173.3 mmol.L-1 added into the medium at the 28th d of culture strongly promoted the cell growth and the formation of the three taxanes in the suspension cells. Compared with those of the control, the cell biomass of the treatments supplemented with phenylalanine and added with sucrose and mannitol at the 28th d of culture increased by 0.6-0.8-fold, taxol yield by 9-10-fold, baccatin III yield by 2.5-3.0-fold, and 10-deacetylbaccatin III yield by 7-fold. Addition of sucrose 73.0 mmol.L-1 at the 28th d of culture significantly promoted the cell growth, but showed little effect on the contents of the three taxanes in the suspension cultures.

Alkaloids↗

PubMed1998

[Detection of heroin metabolites: 6-monoacetylmorphine and morphine in human hair by GC/MS].

This paper presents a method to detect the main metabolites of heroin: 6-monoacetylmorphine (6-MAM) and morphine (MOR) in human hair using GC/MS-SIM. The hair specimens were washed with special solvents and cut into about 0.5 mm pieces. Ethylmorphine was added as internal standard and HCl solution for hydrolysis. After hydrolysis, 6-MAM and MOR were extracted by a mixture of solvents (chloroform-isopropyl alcohol-heptane 50:17:33). The residue of the extract was derivatized with N-methyl-N-trimethylsilyl trifluoroacetamide(MSTFA), then the trimethylsilyl(TMS)-derivatives were qualitatively and quantitatively analyzed using GC/MS-SIM. The correlation coefficients for 6-MAM and MOR were 0.9996 and 0.9997, respectively. The recoveries of both 6-MAM and MOR were over 50%. The RSD of within-day and between-day was less than 8% and 10%, respectively. The lower limit of detection of both 6-MAM and MOR was 0.5 ng.mg-1. Hair samples of 12 drug abusers were analyzed using this method, 8 of them gave positive results. This method is simple, accurate and sensitive. It is very suitable for routine case work.

Gas Chromatography-Mass Spectrometry↗

PubMed1998

[Studies on the chemical constituents of Smilax glabra].

Smilax glabra is a well-known traditional Chinese medicine which has been used clinically to prevent leptospirosis, to treat syphilis, and acute bacterial dysentery, etc. Its extracts showed anti-tumor and anti-atherosclerosis activity. A new isoflavone, 7,6'-dihydroxy 3'-methoxy isoflavone (1), along with two known compounds taxifolin (2) and astilbin (3), have been isolated from the roots of Smilax glabra. The structures were elucidated by spectroscopic methods including 2DNMR techniques.

Drugs, Chinese Herbal↗

PubMed1998

[Synthesis and antiosteoporosis activity of steroid-bisphosphonate compounds].

Bisphosphonate have bone-seeking affinity, some of them are used as drugs for osteoporosis. Steroidal hormones are often used in prevention and treatment of osteoporosis. In order to search for bone-targeted leading compounds with high affinity and low toxicity, seven steroid-bisphosphonate compounds were synthesized. These compounds were found to promote bone formation in bone cell culture.

Animals↗

PubMed1998

[Influence of alum on intestinal flora in mice].

OBJECTIVE: To observe the influence of alum on the intestinal microecological balance in normal microorganisms. METHOD: The mice were administered orally with alum of a small dosage(0.25/kg) and a large dosage(1 g/kg) for half a month, two months and three months, and a micro flora analysis of the mice was carried out at intervals of the above mentioned administrations. RESULT: The intestinal flora in the animals administered with alum was imbalanced. The counts of bifidobacteria and lactobacilli closely related to human physiological activities were decreased. The counts of pathogenic E. Coli significantly increased; and the longer the animals were treated with alum, the stronger the microecological balance was influenced. CONCLUSION: Alum could induce imbalance of the normal intestinal flora in mice.

Alum Compounds↗

PubMed1998

[Serologic testing of hepatitis C virus infection].

We tested anti-HCV, anti-HCV IgM and HCV-RNA in serum samples from general adults, blood donors, acute hepatitis patients and liver cirrhosis patients by the methods of ELISA and RT-PCR so as to study the relationship among serum markers. Results showed that the detected positive rates of anti-HCV are 3.57%, 8.58%, 6.25% and 48.38% in normal adults, blood donors, acute hepatitis patients and liver cirrhosis patients respectively; agreement rates between anti-HCV and HCV RNA are 11.43%, 61.11%, 80.0%, and 73.33% in the four groups of people above; agreement rates between anti-HCV IgM and HCV RNA are 75.0%, 90.9% 81.81% and 100% in the same groups of people. Authors pointed out that anti-HCV IgM is superior to anti-HCV in the aspect of revealing HCV viremia. In comparison with RT-PCR, testing anti-HCV IgM is easier and does not need special instruments, so it is suitable to develop in the basic hygiene units. Testing anti-HCV IgM instead of anti-HCV, the morbidity of post-transfusion hepatitis C can be decreased further.

Antibodies, Viral↗

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

[Construction and identification of recombinant fowlpox virus for expressing haemagglutinin-neuraminidase glycoprotein of Newcastle disease virus strain F48E8].

For the construction of transfer vector pFGHN1175-1, the gene encoding haemagglutinin-neuraminidase(HN) glycoprotein of newcastle disease virus(NDV) strain F48E8 was removed from plasmid pGEMHN, and inserted into the HindIII site of insertion vector pFG1175-1, downstream of P7.5 promotor. Chicken embryo fibroblast (CEF) cell cultures which had been infected with fowlpox virus (FPV) Chinese vaccine strain 282E4 for 3-4 hours were transfected with pFGHN1175-1 plasmid DNA by liposomal transfection. Recombinant FPV with blue plaques were selected and purified 3 times in CEF cell cultures overlaid agarose containing X-gal. PCR analysis and DNA dot-blotting hybridization assay indicated that the HN gene had inserted into the FPV genomic DNA. The expression of the NDV HN gene in recombinant FPV was confirmed by indirect immunofluorescence assay with specific monoclonal antibody.

Animals↗

PubMed1998

[Clustering analysis of phonocardiagrams].

Through the development of the ART-2 neural network, we had constructed the 2-dimensional ART neural network appropriate for clustering the time-varying spectrums. After that, according to the character of phonocardiagram(PCG), we chose the scalogram of PCG to be the input feature of the network. By adjusting parameters the network was enabled to cluster the input PCGs to two clusters. The result demonstrates that the system we designed can pick out, from among 32 continuous PCGs, two PCGs which have the tendency toward abnormality. This result may be applicable to basic physiological studies and clinical diagnosis.

Cluster Analysis↗

PubMed1998

[Effect of various nutrient solutions on quality of Gastrodia elata].

This paper dealed with the effect of media fertilization on the quality of Gastrodia eleta according to the results of tissue culture. The results showed that contents of nutrient elements, gastrodin and free amino acids in G. elata were affected by various nutrients solutions. The result of comprehensive analysis showed that the 1/2 MS medium was the fittest treatment of fertilization.

Amino Acids↗

PubMed1998

Dacryology in China.

PURPOSE: International Society of Dacryology held the IV International Congress in Stockholm on June 1996. I was warmly invited as a guest of honor beforehand to deliver a lecture on a special topic of "Dacryology in China" there, so that the world might understand the dacryology in China, and thus the international growth of dacryology as a discipline would be promoted. METHODS: In China tear lab research and clinical research of LG are nearly empty except a few papers published. We had studied 3 items on LS for 28 years before 1979, and put our attention mainly on dacryology since 1979 by 3 stages: (1) collecting literatures (1979-81); (2) lab research (1981-84) and (3) clinical research, put DE as the key point by 4 steps: DE diagnosis (1984-86); DE treatment (1987-91); DE Condition Judgement (1989-92) & DE cause & mechanism (1991-95). RESULTS: In the past 44 years, esp. from 1979 on, in a planned way, we have systematically researched the dacryology with main results below: created new word "Leiyexue" in Chinese & its English words, dacryology & lacrimology by adding-ology to dacrya & lacrima; made LS consisted of reflex LG & LP, and basic LG besides; found out the normal & abnormal data of tear and serum LF & its iron bindingcapacity; MDH, LDH & isoenzymes; beta 2 m; MDA & antioxidants; trace elements, prostaglandins, intramuscular gentamicin passing the blood-tear barrier; bacteria, fungi, anaerobe, virus & parasite; Ig, T cell & subsets, Langerhan cell, HLA antigen; in cidence (KCS, 0.3-3%, trancomatous DE 0.003%); the parallel correlations between DE graded by rb, BUT & Slt; and in SS, lymphocytes infiltration in LG; Lab G & conjunctiva; LF (< 100 mg%) & beta 2 m (> 1.7 mg%); and testosterone receptors in LG; negated presence of tear Beta-lysim; set up a series of models for researching & a complete set of measures to diagnose, grade, judge and treat DE, deviced new operations. AT & prescription for DE; proved SS being autoimmune & EB virus, its one cause. CONCLUSIONS: This relatively, overall & systematical research of dacryology already have been widely applied to practice with over 100 papers published. It indicates that LS & its disease as a scientific discipline under the term of dacryology to grow up is entirely possible and extremely needful.

Animals↗

PubMed1998

[Room temperature phosphorimetric determination of practolol with dansyl chloride labeling].

Dansyl Chloride (DNS-Cl) was used as a phosphorescent labeling agent for the determination of practolol. The derivative was formed by refluxing practolol-ethyl acetate solution with the solid DNS-Cl in the presence of potassium carbonate anhydride. Room-temperature phosphorescent (RTP) properties of the derivative were studied by a micelle-stabilized room-temperature phosphorescence (MS-RTP) method. Phosphorescence lifetimes of practolol-DNS and the DNS-Cl were found to be 0.791 and 0.408ms, respectively. By applying the derivative MS-RTP technique, practolol could be quantitatively determined without previous separation process. Detection limit of practolol with the proposed method was 0.19 microg/mL.

Dansyl Compounds↗

PubMed1998

[A kind of method for measuring absorbance spectrum with dual beam light and one detector].

A kind of method of measuring spectral transmittivity with source compensated is introduced in this paper. It detects simultaneously intensity of source and transmission light with dual light road and one detector by means of the characters of selective frequence amplifing and coherent detection of a lock-in amplifier. The experimental result shows that the method is excellent on overcoming shake of a source and improving signal-to-noise ratio.

English Abstract↗

PubMed1998

Oltipraz chemoprevention trial in Qidong, People's Republic of China: modulation of serum aflatoxin albumin adduct biomarkers.

In 1995, 234 adults from Qidong, People's Republic of China, were enrolled and followed in a Phase IIa 4-methyl-5-(N-2-pyrazinyl)-1,2-dithiole-3-thione (oltipraz) chemoprevention trial. Residents of this area are at high risk for development of hepatocellular carcinoma, in part due to consumption of aflatoxin-contaminated foods. The intervention was a randomized, placebo-controlled, double-blind study. Elements of the study design and clinical outcomes have been recently published (Jacobson et al, Cancer Epidemiol. Biomark. Prev., 6: 257-265, 1997). The primary objective was to conduct a preliminary assessment of the ability of oltipraz to modulate levels of a validated biomarker of aflatoxin exposure and of the risk of hepatocellular carcinoma by determining levels of aflatoxin-albumin adducts in sera. Healthy eligible individuals were randomized into three arms to receive p.o. 125 mg of oltipraz daily, 500 mg of oltipraz weekly, or placebo for 8 weeks. There were no consistent changes in biomarker levels in the placebo arm over the 16-week observation period, nor was any apparent effect observed in the arm receiving 125 mg of oltipraz each day. However, individuals receiving 500 mg of oltipraz once a week for 8 weeks showed a triphasic response to oltipraz. No effect was observed during the 1st month of the intervention, whereas a significant (P = 0.001) diminution in adduct levels was observed during the 2nd month of active intervention and during the lst month of follow-up. A partial rebound in adduct levels toward baseline values was observed during the 2nd month postintervention. Linear regression models up to week 13 confirmed a significant (P = 0.008) weekly decline of biomarker levels in the group receiving 500 mg of oltipraz once a week. However, despite these effects relative to baseline values within the 500-mg weekly arm, there were no statistically significant differences in biomarker trajectories between treatment arms. The genotype for glutathione S-transferase M1, an oltipraz-inducible isoform involved in the detoxification of aflatoxin B1, did not appear to affect either baseline levels or rates of decline in the biomarker. A follow-up Phase IIb trial with a longer intervention period will be necessary to determine the full extent to which aflatoxin biomarker burden can be reduced and whether diminution of biomarkers can be sustained over the long term.

Adult↗

PubMed1998

KN-93, an inhibitor of multifunctional Ca++/calmodulin-dependent protein kinase, decreases early afterdepolarizations in rabbit heart.

The multifunctional Ca++/calmodulin-dependent protein kinase II (CaM kinase) mediates Ca++-induced augmentation of L-type Ca++ current (ICa); therefore it may act as a proarrhythmic signaling molecule during early afterdepolarizations (EADs) due to ICa. To investigate the hypothesis that ICa-dependent EADs are favored by CaM kinase activation EADs were induced with clofilium in isolated rabbit hearts. All EADs were rapidly terminated with ICa antagonists. Hearts were pretreated with the CaM kinase inhibitor KN-93 or the inactive analog KN-92 (0.5 microM) for 10 min before clofilium exposure. EADs were significantly suppressed by KN-93 (EADs present in 4/10 hearts) compared to KN-92 (EADs present in 10/11 hearts) (P =.024). There were no significant differences in parameters favoring EADs such as monophasic action potential duration or heart rate in KN-93- or KN-92-treated hearts. CaM kinase activity in situ increased 37% in hearts with EADs compared to hearts without EADs (P =.015). This increase in CaM kinase activity was prevented by pretreatment with KN-93. In vitro, KN-93 potently inhibited rabbit myocardial CaM kinase activity (calculated Ki </= 2.58 microM), but the inactive analog KN-92 did not (Ki > 100 microM). The actions of KN-93 and KN-92 on ICa and other repolarizing K+ currents did not explain preferential EAD suppression by KN-93. These data show a novel association between CaM kinase activation and EADs and are consistent with the hypothesis that the ICa and CaM kinase activation both contribute to EADs in this model.

Animals↗

PubMed1998

Factors influencing malaria endemicity in Yunnan Province, PR China (analysis of spatial pattern by GIS). Geographical Information System.

This study is an initial attempt to apply disease mapping through Geographical Information System (GIS) with multiple regression analysis to determine the nature and extent of factors influencing malaria transmission in Yunnan Province, PR China, particularly in border areas. Secondary county-based data covering the period 1990 to 1996 were collected and analyzed. The malaria situation in Yunnan Province as a whole is influenced mainly by the combined effects of the physical environment, the presence of efficient vector species, and mobile population along international borders with Myanmar, Lao PDR and Vietnam.

China↗

PubMed1997

Abscisic acid signaling through cyclic ADP-ribose in plants.

Abscisic acid (ABA) is the primary hormone that mediates plant responses to stresses such as cold, drought, and salinity. Single-cell microinjection experiments in tomato were used to identify possible intermediates involved in ABA signal transduction. Cyclic ADP-ribose (cADPR) was identified as a signaling molecule in the ABA response and was shown to exert its effects by way of calcium. Bioassay experiments showed that the amounts of cADPR in Arabidopsis thaliana plants increased in response to ABA treatment and before ABA-induced gene expression.

Abscisic Acid↗