Biomedical subjects

M He

Publications and source records attributed to M He.

At least 91 records · Page 5Linked to original sources

PubMed1999

Visual acuity and quality of life in patients with cataract in Doumen County, China.

PURPOSE: To evaluate the effectiveness of cataract surgery in achieving sight restoration and vision-related quality-of-life (QOL) in patients from rural southern China. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: A total of 109 cataract operated persons (152 eyes) and 654 unoperated persons. METHODS: Cluster sampling was used in identifying a random sample of 5342 persons 50 years of age and older for visual acuity and eye examinations. Visual functioning (VF) and QOL questionnaires were administered to aphakic and pseudophakic individuals, unoperated persons with presenting visual acuity less than 0.10 in either eye, and a sample of those with normal vision. MAIN OUTCOME MEASURES: Distance visual acuity, VF, and QOL questionnaire scores. RESULTS: Among the cataract operated participants, 43 (39.4%) were bilaterally operated on, 32.1% had presenting visual acuity less than 0.10 in both eyes with 8.3% greater than or equal to 0.32 in both eyes. Of operated eyes, 52.6% presented with visual acuity less than 0.10, 23.7% greater than or equal to 0.32; with best correction, the corresponding percentages were 21.1% and 42.1%. Uncorrectable aphakia due to surgical complications was common. In a multivariate regression model, better visual acuity outcomes were associated with higher level surgeon practice settings and recent surgery. On a 0 to 100 scale, mean VF and QOL scores for the cataract operated population were 41.6 and 54.5, respectively. Mean scores ranged from 84.4 and 93.4, respectively, for the unoperated persons with normal vision, to 14.6 and 31.2, respectively, for those with visual acuity less than 0.05 in both eyes. The VF and QOL scores were closely correlated with presenting visual acuity in both cataract operated and unoperated populations (r = 0.49-0.64). Scores among the cataract operated population were not influenced by age, gender, or education level. Among the unoperated population, lack of education was associated with lower VF and QOL scores (P = 0.017 and P = 0.005, respectively), and older age was associated with lower QOL scores (P < 0.001). CONCLUSION: Patients in rural southern China are not realizing the full sight-restoring potential of modern-day cataract surgery. Remedial efforts are needed to improve the performance of local eye surgeons.

Aged↗

PubMed1999

Dual-energy X-ray absorptiometry for body composition estimation in Chinese women.

OBJECTIVE: To determine whether dual-energy X-ray absorptiometry (DXA) is a valid method for body composition assessment of obese and non-obese subjects. DESIGN: Cross-sectional study. SUBJECTS: Chinese women living in Hong Kong; 66 of 91 subjects had body mass index (BMI) of >25 kg/m2. MEASUREMENTS: Anthropometrics, including body weight, body height, waist and hip girth. Percentage body fat (%BF) and fat-free mass (FFM) from DXA (Hologic 2000 plus, Enhanced Array Whole Body Version 5.63) were compared with that based on a tracer dose of deuterium oxide for the determination of total body water (TBW). RESULTS: In both obese and non-obese subjects, FFMDXA was similar to FFMTBW. The Bland and Altman-type analysis indicated that comparable between-methods differences (mean bias) and limits of agreement were obtained in obese and non-obese subjects for FFM (0.4, between -4.4 and 5.2 kg vs 0.5, between -3.1 and 4.1 kg) and %BF (-0.6, between -7.6 and 6.4% vs -1.2, between -8.6 and 6.2%). The %BF bias was independent of age, BMI, hip circumference, and waist-to-hip ratio, but correlated with waist girth (r=0.24, P=0. 021). CONCLUSION: The sources of bias are methodological and anthropometric in nature. The between-methods differences, however, are small and clinically insignificant. DXA is a valid method for assessing the body composition of obese patients. SPONSORSHIP: This study was supported by a HKU-CRCG grant.

Absorptiometry, Photon↗

PubMed1999

Genetic relationships of populations and the origins of new infestations of the Mediterranean fruit fly.

A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) approach based on the variation in intron sequences of the glucose-6-phosphate dehydrogenase (Zw) gene was used to assess genetic variability in 26 populations and infestations of the Mediterranean fruit fly (medfly), Ceratitis capitata. Beginning with the exon-primed intron-crossing PCR (EPIC-PCR) method to amplify introns of this gene, five alleles were identified on the basis of DNA sequence variants. Several of these variants affect recognition sites for the restriction enzymes RsaI and TaqI. Using these enzymes in successive digestions of the EPIC-PCR products, each of these alleles can be identified directly from individuals. From this, surveys were conducted to document genotypes and allele frequencies in these samples. The relationships of existing populations and the invasion process represented by new infestations of the medfly were analysed using a principal coordinate analysis and the amova method to quantify the distribution of genetic diversity at different levels in a hierarchical manner. From these results, a framework of genetic relationships among the populations and infestations is presented. In addition, for at least some of the infestations, populations that are probably acting as sources of origin have been identified.

Animals↗

PubMed1999

Adaptive changes in postsynaptic dopamine receptors despite unaltered dopamine dynamics in mice lacking monoamine oxidase B.

Monoamine oxidase (MAO) B is considered a key enzyme in dopamine metabolism. The present studies, conducted in MAO B knockout mice, show that lack of MAO B does not alter extracellular levels of dopamine in striatum. Similarly, the synthesis, storage, uptake, and release of dopamine are also unaltered. However, autoradiography revealed a significant up-regulation of the D2-like dopamine receptors in the striatum of MAO B knockout mice. Mutant mice also exhibit a functional supersensitivity of D1-dopamine receptors in the nucleus accumbens. Thus, the agonist SKF 38,393-induced c-Fos immunoreactivity was significantly increased in knockout mice as compared with wild-type controls. In view of the apparently normal basal dopamine dynamics observed in MAO B knockout mice, we hypothesize that a dopamine-independent mechanism underlies adaptations in dopamine receptor function that occur as a consequence of MAO B depletion. Finally, these findings suggest that chronic administration of MAO inhibitors, as occurs in the treatment of Parkinson's disease and depression, may be associated with an increased responsiveness of CNS neurons to dopamine receptor ligands.

Animals↗

PubMed1999

Mitomycin resistance in Streptomyces lavendulae includes a novel drug-binding-protein-dependent export system.

Sequence analysis of Streptomyces lavendulae NRRL 2564 chromosomal DNA adjacent to the mitomycin resistance locus mrd (encoding a previously described mitomycin-binding protein [P. Sheldon, D. A. Johnson, P. R. August, H.-W. Liu, and D. H. Sherman, J. Bacteriol. 179:1796-1804, 1997]) revealed a putative mitomycin C (MC) transport gene (mct) encoding a hydrophobic polypeptide that has significant amino acid sequence similarity with several actinomycete antibiotic export proteins. Disruption of mct by insertional inactivation resulted in an S. lavendulae mutant strain that was considerably more sensitive to MC. Expression of mct in Escherichia coli conferred a fivefold increase in cellular resistance to MC, led to the synthesis of a membrane-associated protein, and correlated with reduced intracellular accumulation of the drug. Coexpression of mct and mrd in E. coli resulted in a 150-fold increase in resistance, as well as reduced intracellular accumulation of MC. Taken together, these data provide evidence that MRD and Mct function as components of a novel drug export system specific to the mitomycins.

Amino Acid Sequence↗

PubMed1999

[The vision distribution and causes of blindness in elderly population in Doumen county].

OBJECTIVE: To investigate the vision distribution and the leading cause of blindness in farmer aged >or= 50 years in Doumen county. METHODS: Cluster sampling size was estimated within an error bound of 0.35% with 95% confidence limit, 1.25 design effect and 85% response rate. Presenting visual acuity was measured by ETDRS (early treatment diabetic retinopathy study) tumbling chart. Eye examinations of external eye, anterior chamber, lens, fundus and intraocular pressure were carried out by ophthalmologists. A diagnosis of the principal cause for all the eyes with presenting visual acuity less than 0.3 was made as well. The field survey was conducted by two teams after pilot agreement testing. RESULT: 5,342 individuals were examined in 36 sampling units. The prevalence of blindness was five-fold in the group aged >or= 70 years than in the group 50 - 59 years. The rate of blindness in the group with less education was higher than the group with 5 years schooling. The leading causes of blindness were cataract (44.90%), cornea opacity (16.36%), globe disorders (10.76%), refractive error (7.08%) and glaucoma (5.88%). CONCLUSIONS: The prevalence of blindness and low vision was 2.67% and 19.91%, respectively in farmers aged >or= 50 years. The leading cause of blindness was cataract.

Age Distribution↗

PubMed1999

[A study on visual function and quality of life in elderly population].

OBJECTIVE: To evaluate the visual impairment by visual function and quality of life assessment in elderly population. METHOD: All subjects aged >or= 50 years were identified by randomly clustering sampling. Visual Function and Quality of Life Questionnaire (VF/QOL) was administered by 5 interviewers for all subjects with presenting visual acuity less than 0.1 in at least one eye (as visual impairment group) and part of the subjects with presenting visual acuity better than 0.3 in both eyes (as control group). RESULTS: Five hundred and thirty-five eligible visual impairment subjects (90.8%) and 119 control subjects were successfully interviewed. In a 0 - 100 scores' scale, the subjective VF and QOL mean scores were 51.0 and 65.9 respectively. The mean score was correlated with age, sex and education. Mean VF and QOL scores decreased from 84.4 and 93.4 to 14.6 and 31.2 along with the visual status worsening from normal to severe blindness respectively. In stepwise linear regression model, the VF and QOL scores were significantly correlated with age and education instead of sex. CONCLUSIONS: In elderly population with visual impairment, subjective visual function and quality of lift status are deteriorated substantially. Their scores are significantly correlated with age and education.

Aged↗

PubMed1999

[The prevalence of cataract in Doumen County, Guangdong Province].

OBJECTIVE: To investigate the prevalence of cataract, cataract blindness and the cataract burden in population aged >or= 50 years in Doumen County. METHOD: 5,759 individuals aged >or= 50 were identified from sampling units. The definition of cataract was the vision < 0.7 caused by lens opacity in either eye, among them the person whose vision in both eyes was < 0.1 was cataract burden and whose vision in both eyes was < 0.05 was cataract blindness. RESULT: The response rate was 92.76%. The prevalence of cataract, cataract blindness and cataract burden was 20.93%, 1.67% and 3.86%, respectively. CONCLUSION: The huge community necessary for cataract surgery still remains as a great challenge in China.

Age Factors↗

PubMed1999

[Effect of food composition of mixed food on glycemic index].

UNLABELLED: In order to study the effect of protein, fat and dietary fiber on glycemic index(GI) of mixed food, the response of blood glucose and plasma insulin to nine diets with different components of food were tested by using glucose oxidase and radioimmunoassay. Glycemic index of 9 mixed foods show as follows, rice: 83.2 +/- 3.1, rice + stir fry pork: 72.0 +/- 14.0, rice + stir fry pork and celery: 57.1 +/- 11.2, rice + stir fry garlic sprout: 57.9 +/- 7.8, rice + stir fry garlic sprout and eggs: 62.8 +/- 16.7, steamed bread: 80.1 +/- 22.5, steamed bread + butter: 68.0 +/- 16.3, and steamed bread + beef: 49.4 +/- 22.8. Protein(P, beta 1 = -0.696, P < 0.01) and dietary fiber(Fi, beta 2 = -7.364, P < 0.01) can reduce the blood glucose response and were significantly related to GI. Fat also can inhibit the increment of blood glucose, but there is no significant relation with GI. When the co-ingestion of protein with carbohydrate, the serum insulin response increased greatly and the glycemic response reduced. The addition of fat can reduce the glycemic response without change in serum insulin. Dietary fiber can reduce the serum insulin response and inhibit the glycemic response. CONCLUSION: Protein and dietary fiber of mixed food could markedly affect the glycemic index of foods and reduced the blood glucose response.

Adult↗

PubMed1998

Modulation of antibody display on M13 filamentous phage.

Here we describe a phage vector for the display of single chain antibodies and polypeptides on the surface of filamentous M13 phage which permits facile manipulation of the valency of display. The gene encoding the polypeptide is fused to a synthetic copy of the major coat protein VIII gene (gpVIII) which permits incorporation into the phage during assembly of the filament. Here we examine the growth parameters of phage propagation on the subsequent selection of an anti-progesterone antibody fragment from a mixture of display phage. Our results suggest that the density of the polypeptides displayed on phage may be modulated by altering growth conditions. This ability to influence polypeptide display density on filamentous phage may provide a versatile approach for accessing complex libraries and the capture of weaker ligand receptor interactions by avidity, whilst the potential to access and discriminate between higher affinity interactions is not negated.

Animals↗

PubMed1998

p73, a gene related to p53, is not mutated in esophageal carcinomas.

A novel gene, termed p73, encodes a protein with a significant homology to p53 and has been mapped at chromosome 1p36.3, which is a locus of multiple suppressor genes for tumors including neuroblastoma and other cancers. Since the 1p36 locus is reported to be deleted and p53 is frequently mutated in esophageal carcinomas, we examined loss of heterozygosity (LOH) and mutation of the p73 gene in 48 untreated esophageal tumors, as well as mRNA expression in 8 tumors. We screened the P1 genomic library to obtain a P1 clone containing the p73 gene and found a polymorphic short tandem CT repeat site at intron 9. Intragenic sequences for 14 PCR primer sets and a primer pair flanking the repeat were also determined for the analysis of PCR single-strand conformation polymorphism (SSCP) and LOH studies, respectively. Expression of p73 mRNA was detectable but at low levels in all 8 tumor tissues by reverse transcriptase PCR. We did not find any type of mutation other than polymorphisms in the 48 esophageal carcinomas, though aberration of the p53 gene on the PCR-SSCP gels was observed in 15 of 38 (39%) tumors of the same set. In addition, LOH for p73 was found in only 2 of 25 (8%) tumors. These results suggest that, at least in esophageal carcinomas, allelic loss or mutation of p73 may not be a main genetic event for the tumorigenesis as it is with p53.

Adenocarcinoma↗

PubMed1998

[Effects of glutamate, glutamate receptor in limbic system and hypothalamus on hypothalamus-pituitary-adrenal axis after rats MCAO].

OBJECTIVE: To investigate the features of activity changes of glutamate(Glu), glutamate receptors(GluR) in hippocampus and hypothalamus during rats middle cerebral artery occlusion (MCAO) or reperfusion. METHODS: Using radio-legend binding assay of receptor (RBA), high-performance liquid chromatography (HPLC) and hybridization in situ and radioimmunometric assay, (RIA), we determined the dynamic changes of Glu content, GluR capacity and it's Kd in cell membrane from the hippocampus of the ischemic brain and the hypothalamus CRHmRNA expression levels in every brain areas and ACTH concentrations in plasma at different time after middle cerebral artery occlusion(MCAO) or reperfusion. RESULTS: Glu content rapidly increased in the hippocampus and the hypothalamus at 15 minutes after MCAO, and reached the peak values at I1 h, and rapidly decreased to the basic-line level after reperfusion. Glu content IR24 h to IR48 h, was elevated again moderately, and declined slowly 48 hours after reperfusion. The GluR was down-regulated and the affinity enhanced in during the ischemic period. During the reperfusion period, the GluR was typically up-regulated. The CRHmRNA expressive levels were markedly enhanced in the tempol cortex, the hippocampus and the hypothalamus at I1 h, and kept to IR96 h, the ACTH concentration in the plasma increased relatively. In the peak time of reperfusion, the Glu content of hypothalamus was positively corrected with CRHmRNA expressive positive cell amounts of the hypothalamus. CONCLUSION: CRH may aggravate ischemic neuronal damage, and Glu participates in the pathogenesis of HPA axis be excited strongly and may be an important impel factor for ACI specially condition.

Animals↗

PubMed1998

[Inferior pulmonary ligament spindle-shaped covering on the anastomotic orifice in the surgery of cardiac carcinoma: experience in 772 patients with no anastomotic leakage or stricture successively].

OBJECTIVE: To prevent anastomotic leakage and stricture after the resection of cardiac carcinoma. METHODS: Since complications are the main causes of postoperative death and poor living quality, we modified anastomotic method, and projected anastomotic orifice to be covered with inferior pulmonary ligament(IPL) in spindle shape. RESULTS: From March 1987 to December 1996, 772 cases of cardiac carcinoma underwent surgical treatment with this method and no anastomotic leakage and stricture developed. CONCLUSION: The IPL has strong ability to adhere and heal. Anastomotic orifice is covered tightly and safely. No forth row 13 needed in not introsed anastomotic orifice, thus preventing stricture, because of lung expanding, IPL adheres to anastomotic orifice tightly, making stump space disappeared. IPL possesses well tenacity and can be used easily.

Adult↗

PubMed1998

[Determination of total amount of acid in soda water by AAS].

A new indirect AAS method for the determination of the total amount of acid in soda water is investigated. After adding MgNH4PO4 reagent to sample solution to react with organic acid, the unreacted reagent subsides by using centrifuge and Mg is detected in solution by AAS. The content of acid is calculated in samples. The results agreed weel with those obtained by volumetric analysis. The relative standard deviations are less than 5.3% and the recoveries are between 91 and 104%.

Acids↗

PubMed1997

Antibody-ribosome-mRNA (ARM) complexes as efficient selection particles for in vitro display and evolution of antibody combining sites.

We describe a rapid, eukaryotic, in vitro method for selection and evolution of antibody combining sites using antibody-ribosome-mRNA (ARM) complexes as selection particles. ARMs carrying single-chain (VH/K) binding fragments specific for progesterone were selected using antigen-coupled magnetic beads; selection simultaneously captured the genetic information as mRNA, making it possible to generate and amplify cDNA by single-step RT-PCR on the ribosome-bound mRNA for further manipulation. Using mutant libraries, antigen-binding ARMs were enriched by a factor of 10(4)-10(5)-fold in a single cycle, with further enrichment in repeated cycles. While demonstrated here for antibodies, the method has the potential to be applied equally for selection of receptors or peptides from libraries.

Animals↗

PubMed1997

Spatial and temporal patterns of acidity and heavy metals in predicting the potential for ecological impact on the Le An river polluted by acid mine drainage.

Integration and comparison of metal contamination from acid mine drainage and an assessment of the potential for ecological impact was conducted in the aquatic ecosystems of the Le An river. The results indicated low acidity, high levels of suspended solids containing a high content of copper in river water and sediment in the upstream region of the Le An river due to the pollution from the Dexing copper mine, and high concentrations of zinc and copper in surface water and sediments, high release potential and ready bioavailability of heavy metals in sediments downstream (after site A07) due to the pollution from the Jishui river. The pollution from acid mine drainage in the Le An river potentially effects an ecological impact on the aquatic ecosystem, mainly between sites A04 and A08. The management strategy should, therefore be mainly applied to acid mine drainage from the Dexing copper mine and heavy metal discharges from the Jishui river.

Acids↗

PubMed1997

Molecular studies on the voltage dependence of dihydropyridine action on L-type Ca2+ channels. Critical involvement of tyrosine residues in motif IIIS6 and IVS6.

The interaction site(s) of dihydropyridine (DHP) antagonists and agonists have been identified by site-directed mutagenesis and localized on motifs IIIS5, IIIS6, and IVS6 of L-type voltage-gated calcium channels. In this study, we investigated the voltage-dependent action of DHPs with mutants of the IIIS6 and IVS6 segments of a cardiac calcium channel. Tyrosine residues in both motifs (Tyr1178 and Tyr1489) strongly contributed to the action of DHP agonists and antagonists. When these two sites were mutated, the communication between the voltage sensor and the DHP interaction site(s) was substantially impaired. In contrast, mutants of a nearby Ile (Ile1182) had much less influence on DHP agonist and antagonist interaction, and the voltage dependence of DHP antagonists was very similar to that of the wild type. The effect of a mutating of Ile1182, on agonist or antagonist action, however, depended strongly on the type of amino acid change. When Ile1182 was substituted with alanine, small changes were noted for DHP agonist and antagonist action. Changing this site into phenylalanine, however, significantly decreased the action of the DHP antagonist. These data show that Ile1182 can preferentially interact with DHP antagonists, but has a lesser contribution in agonist interaction. Thus, even though the agonist and antagonist interaction sites for DHPs with L-type calcium channels may overlap, some amino acids in this site may exhibit a preference for either DHP enantiomers.

Animals↗

PubMed1997

Genotyping of the CYP1A1 and GSTM1 genes in esophageal carcinoma patients with special reference to smoking.

BACKGROUND: Aromatic hydrocarbons, including benzol[a]pyrene, in tobacco smoke first require metabolic activation by phase I enzymes, cytochrome P450s (CYP450s), and then are subjected to detoxification by phase II enzymes, the glutathione-S-transferases. A high risk lung carcinoma group has been reported to have specific polymorphisms of the cytochrome P450 (CYP1A1) gene and the glutathione-S-transferase (GSTM1) gene. In this study, the authors investigated whether such genotypes were also risk factors for esophageal carcinoma. METHODS: Subjects were comprised of 89 esophageal carcinoma patients and 137 noncancer controls. Forty-nine of the patients and 60 of the control subjects were smokers. Genotypic studies of both CYP1A1 and GSTM1 were performed in the cancer tissues of all 89 patients. Genotypes of peripheral blood leukocytes taken from the control subjects were also determined. Genotypes of the CYP1A1 and GSTM1 genes were determined by the polymerase chain reaction. RESULTS: Patients who were heavy smokers with the genotypes Val/Val (V/V) for CYPIAI and the combined genotype of V/V for CYP1A1 and GSTM1- were a statistically high risk group compared with control subjects (P < 0.01, chi-square = 10.6 vs. P < 0.01, chi-square = 11.0). The association of V/V for CYPIAI with a smoking index > or = 600 in esophageal carcinoma patients was estimated at 6.63 (95% confidence interval [CI], 1.86-23.7). The association of combined genotypes of V/V of CYP1A1 and GSTM1 with a smoking index > or = 600 in esophageal carcinoma patients was estimated at 12.7 (95% CI, 1.97-81.8) CONCLUSIONS: Specific genotypes of the CYP1A1 and GSTM1- genes are related to the incidence of esophageal carcinoma, especially in heavy smokers.

Adult↗