Search PubMed⌕ Search

Biomedical subjects

F Zhao

Publications and source records attributed to F Zhao.

At least 91 records · Page 5Linked to original sources
PubMed1998

[Effects of different zinc level diets and heat exposure on the contents of Zn, Cu and Fe in brains of rats].

Forty-eight SD male rats were randomly divided into group A, B and C. Rats in each group were also divided into 2 parts. One part was used for heat exposure and the other was used for room temperature control. On the basis of AIN-93 m diet composition, group A, B and C zinc diets were prepared by adding or reducing zinc carbonate. Zinc contents of group A, B and C zinc diet per kilogram were 92.2 mg, 45.61 mg and 21.70 mg respectively. 14 days later the rats were exposed to high temperature (Tdb 40 degrees C, Twb 30.8 degrees C) for 3 hours. The Contents of Zn, Cu and Fe in hippocampus, cerebral cortex and cerebellum of rats were determined by atomic absorption spectrophotometer. The results revealed that 1. hyperthermal exposure could increase Cu content in rat hippocampus significantly, 2. after heat exposure, Cu content in hippocampus was higher than in cerebral cortex and cerebellum. Cu contents in cerebellum of room temperature control rat were higher than cerebral cortex and hippocampus, 3. intakes of different zinc level diets chiefly influenced content of Cu rat cerebellum and slightly affected iron content in it, 4. high, middle level zinc diet intake could reduce Cu content in heat-stressed rat cerebellum.

Animals↗
PubMed1998

[A FISH technique for simultaneous detection of fluorescent R-band and in situ hybridization signals].

OBJECTIVE: To develop a simple method for detecting DNA probes directly on R-banded chromosomes. METHODS: After sixty-seven hours culture, human peripheral blood lymphocytes were synchronized for 5 to 6 hours by adding Hoechst 33258 and BUdR, and then arrested by standard cytogenetic procedures. The slides were mounted with 2 x SSC and exposed with a 20W UV light which was about 10cm above the slides for 20 min at 75 degrees C. The biotinylated probes, such as the cosmid and YAC clones on 5p specific region and pBamX7, were hybridized on to the slides. After washing, the slides were treated with avidin-FITC and amplified with additional layer of biotinylated anti-avidin and avidin-FITC, and counterstained with propidium iodide in an antifade solution. Fluorescent signals and R-bands were observed simultaneously under Olympus BX 60 fluorescence microscope equipped with a WIB filter. RESULTS: The chromosomal location of the greenish-yellow signals could be directly identified on the R-banded chromosome background. CONCLUSION: This method can serve as a rapid and precise system for chromosomal localization of DNA markers.

Chromosome Banding↗
PubMed1998

Use of patient-specific estimates in patient evaluation and rehabilitation.

For a number of years we have been using open-ended questionnaires in the assessment of hearing disability and handicap, tinnitus complaint behaviour together with shortcomings and benefits of various rehabilitative interventions. More recently we have applied this approach to positive experiences reported by adults who have developed a hearing impairment and to the use of silence or social withdrawal as a communication tactic. In addition, we have asked individuals to rate the magnitude of each of their listed disabilities, handicaps, shortcomings, etc., on a scale to provide a qualitative assessment of each of these elements important to the individual. Such a procedure can be repeated after the intervention to measure changes in such estimates. This approach can thus highlight for the therapist, those elements of the patients' problems which are being well or poorly addressed and hence help them to concentrate their effort on the latter. Results obtained using this technique are presented and discussed.

Aged↗
PubMed1998

Effects of repletion with zinc and other micronutrients on neuropsychologic performance and growth of Chinese children.

The knowledge that zinc is essential for growth and neuropsychologic performance and a report of zinc-responsive stunting in Chinese children prompted this project. This article summarizes findings from a 10-wk, double-blind, controlled trial of zinc repletion in 740 urban, 6-9-y-old first graders from low-income families in Chongqing, Qingdao, and Shanghai, People's Republic of China. Treatments were 20 mg Zn alone (Z), 20 mg Zn with micronutrients (ZM), and micronutrients alone (M). The M mixture was based on National Research Council guidelines. Nutrients that might interfere with zinc retention were excluded or given in lower amounts. Main outcomes were changes in neuropsychologic performance and knee height. Hemoglobin, serum ferritin, plasma and hair zinc, and whole blood and hair lead were also measured. Anemia was not common, and serum ferritin concentrations were usually within the range of normal. Mean baseline plasma zinc concentrations were marginal in children from Chongqing and Qingdao and normal in children from Shanghai. After treatment with ZM or M plasma zinc increased. Hair zinc tended to decrease after all treatments. Mean baseline whole blood lead concentrations were slightly below the limit considered excessive for children by the US Centers for Disease Control and Prevention. Neuropsychologic performance and growth were most improved after treatment with ZM. These findings were consistent with the presence of zinc and other micronutrient deficiencies.

Brain↗
PubMed1998

Relative biologic availability and pharmacokinetics of albuterol preparations in healthy Chinese.

The authors' goal was to study the biologic availability and pharmacokinetics of two different formulations of controlled-release (CR) tablets of albuterol. A two-way, cross-over biologic availability study was performed with 20 healthy male volunteers to evaluate the relative biologic availability of two CR tablets of albuterol versus two different formulations of immediate-release (IR) albuterol tablets. Albuterol concentrations in plasma were measured using an HPLC procedure. Each patient subject received a 4.8-mg CR tablet every 12 hours for 6 days and a 4.8-mg IR tablet every 8 hours for 6 days. Tests of single doses and steady state were assayed for CR and IR albuterol tablets. The mean Cmax and tmax for two CR tablets given after a single dose were 7.3+/-1.5, 7.9+/-1.4 microg x L(-1) and 4.6+/-0.8, 4.8+/-0.5 hours, respectively. The Cmax and tmax for two IR tablets given after a single dose were 12.5-/+1.3, 15.3 +/-2.3 microg x L(-1) and 1.3+/-0.4, 1.6+/-0.4 hours, respectively. The relative biologic availability of two CR albuterol tablets were 106.0+/-6.2% and 109.8+/-9.0%, respectively. Administration of CR albuterol twice a day provides an alternative to administration of IR albuterol three or four times a day.

Adult↗
PubMed1998

[Clinical analysis of intracranial venous embolism during pregnancy and puerperium].

OBJECTIVE: To study the cause and clinical manifestation of intracranial venous embolim during pregnancy and puerperium, and its early diagnosis and treatment. METHODS: 18 cases of intracranial venous embolism confirmed by Computed Tomography (CT) were eligible for this retrospective study. RESULTS: Of all the cases, 8 cases occurred before delivery and 10 post partum; 10 cases complicated by pregnancy induced hypertension and 8 cases postpartum hemorrhage. Headache occurred most frequently, followed by coma and seizure. Blood rheologic assay showed hypercoagulable states in 6 cases. For 11 cases treated with urokinase, 10 were cured, while in the remaining patients, 3 of 6 cured. CONCLUSIONS: The results show that hypercoagulability states were related to intracranial venous embolism. Coma and seizure were the main characters. CT was an important diagnostic measure. Lowering intracranial pressure, anticoagulation, dethrombosis and timely ending pregnancy were the main treatment measures. The early use of urokinase may exert better effect.

Adult↗
PubMed1998

[Determination of tranilast in human plasma by reversed-phase high performance liquid chromatography and its pharmacokinetics].

A simple and rapid method for the determination of tranilast in human plasma by RP-HPLC is described. The analytical column was packed with YWG-C18. The mobile phase consisted of methanol-0.02 mol/L KH2PO4(60:40, V/V; pH 4.2), and detected by UV detector at a wavelength of 333 nm. The plasma sample was injected directly into the HPLC system after precipitation of the protein with methanol. The calibration curve was linear within the concentration range of 0.625-40 mg/L. The average recovery was 100.0% +/- 4.1%, and minimum detectable concentration was 0.2 mg/L. By using this method, the pharmacokinetics of tranilast in the plasma of ten healthy volunteers after oral administration of 200 mg drug were studied. The plasma drug concentration-time curve of volunteers conforms to one-compartment open model.

Anti-Allergic Agents↗
PubMed1998

A potential approach to antifertility vaccine by expression of sperm membrane peptide in Salmonella.

A synthetic oligonucleotide, HSD-2a, encoding a peptide segment of the extracellular domain of a human sperm membrane protein, YWK-II, was inserted by blunt-end ligation at the EcoRV site in the hypervariable, antigenically determinant region IV of Salmonella flagellin gene fliC (d). The recombinant plasmid (pLS408-H1) was transferred into the nonpathogenic aroA live vaccine Salmonella dublin strain SL5928, which is flagellin-negative. Location of the HSD-2a protein on the surface of the flagella was demonstrated by ELISA and by immunogold-labeling electron microscopy using mouse anti-YWK-II antiserum. A 60 kD protein, corresponding to the chimeric flagellin, was isolated from the recombinant S. dublin and found to contain the expressed HSD-2a peptide determined by Western blot analysis using anti-YWK-II antiserum. The Salmonella strain carrying the recombinant plasmid-pLS408-H1 may thus be a potential source of antifertility vaccine.

Amyloid beta-Protein Precursor↗
PubMed1998

[Experimental research on laser-induced single-molecule detection].

Single-molecule detection is a kind of ultra-high sensitive detection technique. It is widely used in biology, medicine, environment and so on. Here we report briefly the principle and device of our laser-induced single-molecule detection spectrum instrument. We also report the experimental results on the instrument by using C445 dye, including the affection of sample velocity, energy characteristic, consistence linearity and detection limit. We discuss the effect of photon bleach on experimental results. These results are the base of our future work.

Chemistry Techniques, Analytical↗
PubMed1998

[Application of charge transfer reaction in the determination of aminosalicylate sodium].

A spectrophotometric method for the determination of aminosalicylate sodium has been developed based on the charge transfer reaction. The Beer's law is obeyed in the range of 40-160 microg/mL of aminosalicylate sodium. The apparent molar absorptivity of the complex at 660nm is 1.17 X 10(3)L x mol(-1). The average standard deviation of ten determination is 0.67%. The composition of aminosalicylate sodium 2, 6-Dichloroquinone chlorimide complex is 1:1. The proposed method has been applied to the determination of aminosalicylate sodium tablets with satisfactory results.

Absorption↗
PubMed1998

[Application of chromosome painting to analysis of structural aberration in five cases].

OBJECTIVE: This article reports that competitive hybridization using entire chromosome specific libraries as probe and human genomic DNA as the competitor allows intense and specific fluorescent staining of human chromosome in metaphase. This general approach is called "chromosome painting". METHODS: The probes comprising chromosomes 2, 5, 6, 7, 13, 14, X specific libraries were used to analyse five cases which had been suspected of subtle translocation and deletion in karyotype analysis by G-banding of metaphase cells. The authors selected entire chromosome-specific DNA libraries hybridizing with the five cases. Unlabeled human genomic DNA was used to inhibit the hybridization of sequences in the library that bind to multiple chromosome. RESULTS: The target chromosome was made at least 20 times brighter parunit length than the others. Translocations and deletions were detected clearly in metaphase and were consistent with G-banding. However, the result was clearer and the detection easier, compared with G-banding. CONCLUSION: Chromosome painting is very powerful for identification of chromosome structural aberrations. Translocation and deletion involving these chromosomes can be strikingly visualized. The hybridization intensity and specificity are such that even very small portions of the involved chromosome can be detected. This technique is especially useful in settings where high-quality banding is difficult.

Adult↗
PubMed1997

A case-control study of diet and lung cancer in northeast China.

A case-control study involving interviews with 227 lung-cancer cases and 227 matched hospital controls was conducted in Heilongjiang Province in northeast China to examine the influence of dietary factors on the risk of developing lung cancer. Lung-cancer cases were all incident cases judged to be suitable candidates for tumor removal by surgery. Controls were selected among hospitalized patients with non-neoplastic and non-lung disease. The overall male lung-cancer risks associated with cigarette smoking were similar to those reported in other Chinese studies but quite low compared to risks in Western countries. However, the subjects in this study were relatively young (average age 53.2), had started to smoke on average at a relatively old age (21.3 years), and only smoked an average of 18.7 cigarettes per day. Lung-cancer risk was not strongly associated with any of the nutrients examined, when all cases were compared to all controls. However, the data were suggestive of differences in the relationship of diet to risk among smokers and non-smokers. Cautious interpretation is required because of the wide confidence intervals due to limited sample size. Among the smokers, only higher beta-carotene was associated with estimates suggesting a lowered risk. Among non-smokers, the evidence suggested that increased vegetable consumption might reduce risk, consumption of any fruit might reduce risk but beta-carotene was unrelated to risk. The differences observed in the relationship of diet to lung-cancer risk between Chinese smokers and non-smokers warrant further study.

Case-Control Studies↗
PubMed1997

Metal-catalyzed oxidation of histidine in human growth hormone. Mechanism, isotope effects, and inhibition by a mild denaturing alcohol.

Metal-catalyzed oxidation of proteins represents an important pathway of post-translational modification. We utilized human growth hormone (hGH), a protein with a well defined metal-binding site, to study the detailed mechanism of metal-catalyzed oxidation by ascorbate/Cu(II)/O2. Particularly His18 and His21 within the metal-binding site were oxidized, predominantly to 2-oxo-His with the incorporated oxygen originating from molecular oxygen, based on amino acid analysis, tryptic mapping, mass spectrometry, isotopic labeling, and 1H NMR. The anaerobic reduction of a hGH/Cu(II) mixture by ascorbate generated a hGH-Cu(I) complex with NMR spectral features different from those of native hGH and hGH/Cu(II). The anaerobic reaction of this hGH-Cu(I) complex with hydrogen peroxide resulted in the oxidation of His18 and His21, suggesting that a fraction of Cu(I) was bound at the metal-binding site of hGH. Site-specific oxidation of hGH required an intact metal-binding site and could largely (about 80%) be inhibited by the presence of >/=28% (v/v) 1-propanol which appears (i) to perturb the metal-binding site and (ii) to interact with a reactive oxygen species formed at the perturbed metal-binding site. The inhibition by 1-propanol-d7 (CD3CD2CD2OH) was significantly lower than that by 1-propanol-h7 with [residual hGH]1-propanol-h7/[residual hGH]1-propanol-d7 = 1.95 at 30% (v/v) 1-propanol, reflecting a kinetic isotope effect close to that for the reaction of a hydroxyl radical with Calpha-H/D bonds of methanol, suggesting the involvement of a hydroxyl radical-like species in the oxidation of His.

1-Propanol↗
PubMed1997

Inhibition of 3,3',4,4',5-pentachlorobiphenyl-induced chicken embryotoxicity by 2,2',4,4',5,5'-hexachlorobiphenyl.

3,3',4,4',5-Pentachlorobiphenyl (pentaCB) caused a dose-dependent induction of chicken embryolethality, malformations, edema, and liver lesions at doses ranging from 0.5 to 12.0 microg/kg. In contrast, no embryotoxicity was observed after treatment with 10, 25, or 50 mg/kg 2,2',4,4',5,5'-hexaCB. In eggs cotreated with 2.0 microg/kg, 3,3',4,4',5-pentaCB plus 10, 25, or 50 mg/kg 2,2',4,4',5,5'-hexaCB, there was significant protection from 3,3',4,4',5-pentaCB-induced embryo malformations, edema, and liver lesions, whereas no inhibition of embryolethality was observed. These results further extend the response-specific nonadditive interactions of binary mixtures of polychlorinated biphenyls (PCBs) and should be considered in the development of approaches for hazard assessment of PCB mixtures and related compounds.

Abnormalities, Drug-Induced↗
PubMed1997

The use of qualitative questionnaires in patients having and being considered for cochlear implants.

Within this study we have examined the particular hearing complaints of patients being considered for a cochlear implant and the specific benefits/shortcomings experienced by implanted patients using open-ended questionnaires. As we expected, the difficulty of hearing general conversation was the most common individual hearing complaint. However, 45% of complaints were concentrated in the 'psychosocial' category, which was significantly higher than that found among general audiological rehabilitation patients. The average number of benefits listed by patients having implants was significantly higher than that of the shortcomings. Moreover, the main benefits listed were focused on the acoustical and psychological factors, e.g. 'environmental sound awareness', 'general conversation easier' and 'feeling of self-confidence'. The main shortcomings were related to the acoustical and practical areas, e.g. hearing difficulty in noisy background, processor being cumbersome.

Cochlear Implants↗
PubMed1997

A preliminary report: effects of zinc and micronutrient repletion on growth and neuropsychological function of urban Chinese children.

OBJECTIVE: Zinc is essential for growth and cognition of experimental animals. Past research found zinc repletion improved growth of stunted Chinese children. Therefore we measured effects of zinc repletion on growth and neuropsychological functions of children. DESIGN: Double-blind randomized controlled treatment trial. SETTING: Elementary schools in low income districts of Chongqing, Qingdao and Shanghai. SUBJECTS: Three hundred-seventy-two 6 to 9 year old first graders. INTERVENTIONS: Treatments were 20 mg zinc, 20 mg zinc with micronutrients, or micronutrients alone. The micronutrient mixture was based on guidelines of the US NAS/NRC. Treatments were assigned to classrooms of 40 or more children each, and administered by teachers 6 days per week for 10 weeks. MEASURES OF OUTCOME: Changes in knee height and neuropsychological functions. RESULTS: Zinc alone had the least effect on growth while zinc with micronutrients had the largest effect; micronutrients alone had an intermediate effect. Zinc-containing treatments improved neuropsychological functions, but micronutrients alone had little effect. CONCLUSIONS: The findings confirm the essentiality of zinc for growth of children, and show, for the first time, the essentiality of zinc for neuropsychological functions of children. In addition, the need for repletion of other potentially limiting nutrients in studies examining the effects of specific nutrients on growth and neuropsychological functions was confirmed.

Analysis of Variance↗
PubMed1997

Neurofibromatosis 2 tumor suppressor protein colocalizes with ezrin and CD44 and associates with actin-containing cytoskeleton.

Neurofibromatosis 2 (NF2) protein (merlin; schwannomin) is a tumor suppressor involved in tumorigenesis of NF2-associated and sporadic schwannomas and meningiomas. The protein shares the domain structure of three homologous proteins: ezrin, radixin and moesin (ERM). ERM proteins function as membrane organizers and may act as linkers between plasma membrane molecules, such as CD44 and ICAM-2, and the cytoskeleton. We analyzed the distribution and effects of transfected NF2 protein in COS-1, CHO and 293 cells, and endogenous NF2 protein in U251 glioma cells. The distribution was compared to ezrin, CD44 and F-actin. Both transfected and endogenous NF2 protein localized underneath the plasma membrane in a pattern typical of an ERM protein. In COS-1 transfectants, NF2 protein typically codistributed with ezrin but, in cells with poorly developed actin cytoskeleton, it replaced ezrin in filopodia and ruffling edges. NF2 protein colocalized with CD44, which in transfected cells accumulated into restructured cell membrane protrusions. The association of CD44 and NF2 protein was further suggested by binding of CD44 from cellular lysates to recombinant NF2 protein. Interaction between NF2 protein and the actin-containing cytoskeleton was indicated by partial colocalization, by cytochalasin B-induced coclustering, and by retention of NF2 protein in the detergent-insoluble fraction. Transfected NF2 protein induced morphogenic changes. The cells contained restructured membrane extensions and blebs, and CHO cells expressing NF2 protein were more elongated than control transfectants. In conclusion, NF2 protein possesses functional properties of an ERM family member.

Actins↗