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Biomedical subjects

R H Zhou

Publications and source records attributed to R H Zhou.

At least 19 recordsLinked to original sources
PubMed2005

Microsatellite mapping of a Triticum urartu Tum. derived powdery mildew resistance gene transferred to common wheat (Triticum aestivum L.).

A powdery mildew resistance gene from Triticum urartu Tum. accession UR206 was successfully transferred into hexaploid wheat (Triticum aestivum L.) through crossing and backcrossing. The F1 plants, which had 28 chromosomes and an average of 5.32 bivalents and 17.36 univalents in meiotic pollen mother cells (PMC), were obtained through embryos rescued owing to shriveling of endosperm in hybrid seed of cross Chinese Spring (CS) x UR206. Hybrid seeds were produced through backcrossing F1 with common wheat parents. The derivative lines had normal chromosome numbers and powdery mildew resistance similar to the donor UR206, indicating that the powdery mildew resistance gene originating from T. urartu accession UR206 was successfully transferred and expressed in a hexaploid wheat background. Genetic analysis indicated that a single dominant gene controlled the powdery mildew resistance at the seedling stage. To map and tag the powdery mildew resistance gene, 143 F2 individuals derived from a cross UR206 x UR203 were used to construct a linkage map. The resistant gene was mapped on the chromosome 7AL based on the mapped microsatellite makers. The map spanned 52.1 cM and the order of these microsatellite loci agreed well with the established microsatellite map of chromosome arm 7AL. The resistance gene was flanked by the microsatellite loci Xwmc273 and Xpsp3003, with the genetic distances of 2.2 cM and 3.8 cM, respectively. On the basis of the origin and chromosomal location of the gene, it was temporarily designated PmU.

Ascomycota↗
PubMed2004

One hundred and one new microsatellite loci derived from ESTs (EST-SSRs) in bread wheat.

Four hundred and seventy-eight microsatellite markers derived from expressed sequence tags (EST-SSRs) were screened among three mapping populations (W-7984xOpata 85, WOpop; LumaixHanxuan, LHpop; WenmaixShanhongmai, WSpop). The number of polymorphic EST-SSR primer pairs found in WOpop, LHpop and WSpop was 92, 58 and 29 respectively. A total of 101 EST-SSR loci amplified from 88 primer sets were distributed over the 20 chromosomes of the reference maps (no markers were located on chromosome 4B). These 101 mapped EST-SSR markers add to the existing 450 microsatellite loci previously mapped in bread wheat. Seventy-four of the 101 loci showed significant similarities to known genes, including 24 genes involved in metabolism, 4 in cellular structures, 9 in stress resistance, 12 in transcription, 2 in development, 2 transporters and 21 storage proteins. Besides gliadin and glutenin, most of the 53 genes with putative functions were mapped for the first time by EST-SSR markers in bread wheat. Sequence alignment of the mapped wheat EST-SSR loci allowed tentative assignment of functionality to the other members of grasses family. Colinearity combined with homology information offers an attractive approach to comparative genomics.

Chromosome Mapping↗
PubMed2001

Characterization of the human NDRG gene family: a newly identified member, NDRG4, is specifically expressed in brain and heart.

RTP/Drg1/Cap43/rit42/TDD5/Ndr1/NDRG1 (referred to as NDRG1 hereafter) is a cytoplasmic protein involved in stress responses, hormone responses, cell growth, and differentiation. Recently, the mutation of this gene was reported to be causative for hereditary motor and sensory neuropathy-Lom. Here, we cloned two human cDNAs encoding NDRG3 and NDRG4, which are homologous to NDRG1. These two genes, together with NDRG1 and a previously deposited cDNA (designated NDRG2), constitute the NDRG gene family. The four members share 57-65% amino acid identity. NDRG4 was further characterized because its mRNA expression was quite specific in brain and heart, in contrast to the relatively ubiquitous expression of the other three members. NDRG4 mRNA consists of three isoforms, NDRG4-B, NDRG4-B(var), and NDRG4-H. Northern and Western blot analyses showed that NDRG4-B was expressed only in the brain, whereas NDRG4-H was expressed in both brain and heart. NDRG4-B(var) was a minor product. NDRG4 expression was more abundant in adult than fetal brain and heart and was markedly decreased in the Alzheimer's diseased brain. In situ hybridization showed that NDRG4 was localized in neurons of the brain and spinal cord. The NDRG4 gene contains 17 exons. mRNA expression of the three NDRG4 isoforms is regulated by alternative splicing and possibly by alternative promoter usage. The finely tuned expression of the NDRG gene family members suggests that they have different specific functions.

Amino Acid Sequence↗
PubMed2001

Changes in serum interleukin-8 and interleukin-12 levels in patients with ischemic heart disease in a Chinese population.

Increasing evidence has indicated the important roles of inflammation and immune response in the development of atherosclerosis and ischemic heart disease (IHD). We measured the serum interleukin (IL)-8 and IL-12 levels of patients with unstable angina pectoris (UAP) and patients with acute myocardial infarction (AMI), and compared findings with those of normal subjects. The results showed that the serum level of IL-8 was significantly higher in patients with UAP and patients with AMI than in healthy control subjects. To our knowledge, this is the first report that serum IL-12 level was elevated in patients with AMI but not in patients with UAP. These findings suggest that IL-8 and IL-12 are involved in the process of IHD, and serum IL-12 may be a marker for differentiating AMI from UAP.

Aged↗
PubMed1999

Effects of storage and cooking on the iodine content in iodized salt and study on monitoring iodine content in iodized salt.

In order to ensure that the intake of iodine from iodized salt is adequate, the effects of cooking, storage and iodination on iodine content in iodized salt have been studied. For monitoring the analytical performance, a quality control examination was also undertaken. The loss of iodine was greater when salt was stored in plastic bag than in glass bottle. The loss was greater in fortified salt stored at 37 degrees C and under 76% humidity than in that at 20-25 degrees C and under lower humidity. The retention of iodine varied with the kind of foods and also was influenced by the water content of cooked food. In general, the retention of iodine during cooking varied considerably (from 36.6% to 86.1%). The iodine concentration in salts varied greater from 3.0 to 100.3 mg/kg in salt for markets, and from 0 to 90.0 mg/kg in salts for households. 48.3% of samples from markets were found to be in compliance with national standards (30-50 mg/kg), and 72.0% of samples from households were in compliance with national standard (20-50 mg/kg). Analytical data collected from 8 of the cooperative laboratories for an analytical reference material showed a 95% confidence interval of the population mean for both precision and accuracy, falling within X +/- 2SD and passing quality control examination.

Food Preservation↗
PubMed1998

Circadian and septadian variation in the occurrence of acute myocardial infarction in a Chinese population.

To investigate whether circadian or any other temporal pattern(s) exist in the occurrence of acute myocardial infarction (AMI) in a Chinese population, we analyzed 428 patients with confirmed AMI for temporal patterns of AMI occurrence. The patients admitted to the Affiliated Hospital of Shandong Medical University during 1991-95 were from Jinan, the capital city of Shandong Province of China, which has a population of 2.5 million. The chi-square test for goodness of fit was used to test the difference among the frequencies of AMI occurrence in 4 equal intervals (01.00-07.00 h, 07.00-13.00 h, 13.00-19.00 h, 19.00-01.00 h) during the day and among those on 7 days during the week. The results showed that AMI occurrence exhibited significant circadian (p<0.001) and septadian (day of the week) (p=0.046) periodicity, with a peak at 01.00-07.00 h and a trough at 13.00-19.00 h during the day, and a peak on Saturday and a trough on Wednesday during the week. The peak to trough ratio of risk was 2.7 during the day and 2.1 during the week. It is concluded that there were circadian and septadian biorhythms in AMI occurrence in the Chinese population and that these were different from those observed in Western populations. Further investigation of the underlying mechanisms may shed further light on the trigger mechanisms of AMI and thus be helpful in the prevention and treatment of AMI.

Acute Disease↗
PubMed1997

A precise interchromosomal reciprocal exchange between hot spots for cleavable complex formation by topoisomerase II in amsacrine-treated Chinese hamster ovary cells.

Among the aprt mutations induced in confluence-arrested Chinese hamster ovary D422 cells by the topoisomerase II poison amsacrine, there was a reciprocal exchange between the aprt gene and an unrelated sequence, accompanied by a chromosomal translocation at the aprt locus. The breakpoints in both parental sequences were hot spots for amsacrine-stimulated DNA cleavage in vitro, and the novel junctions formed were precisely as expected for a mechanism involving reciprocal exchange of topoisomerase II subunits followed by resealing of the breaks and correction of mismatches in the cohesive ends. The results are consistent with a role for direct subunit exchange in the production of chromosomal translocations by topoisomerase poisons, although more complex models involving double-strand breakage and repair could produce reciprocal exchanges of similar specificity.

Adenine Phosphoribosyltransferase↗
PubMed1997

Highly conservative reciprocal translocations formed by apparent joining of exchanged DNA double-strand break ends.

Chromosomal translocations induced by ionizing radiation and radiomimetic drugs are thought to arise by incorrect joining of DNA double-strand breaks. To dissect such misrepair events at a molecular level, large-scale, bleomycin-induced rearrangements in the aprt gene of Chinese hamster ovary D422 cells were mapped, the breakpoints were sequenced, and the original non-aprt parental sequences involved in each rearrangement were recovered from nonmutant cells. Of seven rearrangements characterized, six were reciprocal exchanges between aprt and unrelated sequences. Consistent with a mechanism involving joining of exchanged double-strand break ends, there was, in most cases, no homology between the two parental sequences, no overlap in sequences retained at the two newly formed junctions, and little or no loss of parental sequences (usually </=2 bp) at the breakpoints. The breakpoints were strongly correlated (P < 0.0001) with expected sites of bleomycin-induced, double-strand breaks. Fluorescence in situ hybridization indicated that, in six of the mutants, the rearrangement was accompanied by a chromosomal translocation at the aprt locus, because upstream and downstream flanking sequences were detected on separate chromosomes. The results suggest that repair of free radical-mediated, double-strand breaks in confluence-arrested cells is effected by a conservative, homology-independent, end-joining pathway that does not involve single-strand intermediate and that misjoining of exchanged ends by this pathway can directly result in chromosomal translocations.

Adenine Phosphoribosyltransferase↗
PubMed1997

Effects of isolation housing and timing of drug administration on amikacin kinetics in mice.

AIM: To study the influences of social condition and drug administration time on amikacin metabolism in mice. METHODS: Forty Male ICR mice were randomly assigned into 4 groups according to 1) housing condition: individual housing (I, one mouse in a cage) or aggregated housing (A, 10 mice in a cage) and 2) drug administration time: at midday (D) or at midnight (N), i.e. I-D, I-N, A-D, and A-N groups. Amikacin was injected s.c. 15 mg.kg-1 after 4 wk of raising at D or N. Blood samples were taken at 5, 10, 15, 20, 30, and 60 min after medication in each mouse. Plasma amikacin was measured by enzyme immunoassay. The concentration-time data were fitted with one-compartment open model in each mouse and data were analyzed with group t test. RESULTS: The clearance (Cl) of amikacin was larger and the half-life (T1/2) was shorter in A-N group than in A-D or I-N groups respectively. AUC(0-1) in A-N group was less than in I-N group. No differences of kinetic parameters between 2 isolated housing (I-D and I-N) groups were found. CONCLUSION: Aggregated housing and midnight drug administration increased the disposition of amikacin.

Amikacin↗
PubMed1995

Application of urinary mutagen testing to detect workplace hazardous exposure and bladder cancer.

The objectives of this biochemical epidemiologic case-control study were to evaluate urinary mutagen testing for occupational exposure assessment, and for possible screening for bladder cancer in the workplace. Thirty-seven patients (19 bladder cancer cases and 18 controls) completed a questionnaire. Two urine samples, i.e. a work sample taken while at work, and a home sample, were requested from each patient. Twenty-six patients (17 cases and 9 controls) gave a total of 47 24-h urine samples for mutagenicity testing by the Ames test. A positive Ames test was found to be associated significantly with current occupation with hazardous exposure (odds ratio = 3.7, 95%CI 1.1-12.9), and non-significantly with bladder cancer (odds ratio = 1.8, 95%CI 0.5-7.1). Our results show that the urinary Ames test has the potential of being used as a surveillance for current workplace hazardous exposure (sensitivity = 52%, specificity = 77%, positive predictive value = 72%, negative predictive value = 59%, positive likelihood ratio = 2.3), but not as a screening test for bladder cancer cases (sensitivity = 42%, specificity = 71%, positive predictive value = 3%, negative predictive value = 98%, positive likelihood ratio = 1.5).

Adult↗
PubMed1993

[Macrological identification of original and commercial Chinese drug gusuibu (Rhizoma drynariae)].

Twelve original species and 7 commercial species of Chinese drug Gusuibu were identified and discussed based on macrological observation and comparison. The survey of 65 samples collected from 23 provinces throughout the country showed that at the present time the major species of commercial Gusuibu is derived from the rhizomes of Drynaria fortunei, which makes up more than 70 percent of the total samples.

Medicine, Chinese Traditional↗
PubMed1992

Effects of isolation housing and timing of drug administration on theophylline kinetics in mice.

ICR mice were grouped according to 1) housing environment: individual (I) or aggregated (A) and 2) timing of drug administration: midlight (L) or middark (D), i.e. I-L, I-D, A-L, A-D groups. Theophylline was orally administered at midlight or middark. The results showed that both social environment and timing of drug administration exerted significant influence on the pharmacokinetics of theophylline. These data may suggest the importance of considering many non-drug factors in toxicological studies with experimental animals.

Animals↗
PubMed1991

[A histopathological study of bone marrow in acute myeloid leukemia. Bone marrow biopsy changes before chemotherapy and comparison with bone marrow smears].

Histopathological changes of pretreatment bone marrow biopsy from 42 cases with acute myeloid leukemia (AML) were described. A considerable difference was shown between the results of aspirate smears and the findings of plastic embedded biopsy sections, particularly in bone marrow cellularity such as infiltration of inflammatory cells and presence of residual hemopoietic cells, qualitative and quantitative abnormalities of megakaryocytes suggestive of myelodysplastic features were more accurately assessed in the sections of marrow biopsy than in the aspirate smears. In three cases there was considerable infiltration of maturing but dysplastic granulocytic cells and erythroid precursors in the sections, but not in the aspirate smears. Our study shows that plastic embedded biopsy sections provide more information than aspiration smears for the diagnosis of AML.

Adolescent↗
PubMed1990

[Epiduralography for diagnosis of lumbar intervertebral disc protrusion: report of 304 cases].

The authors used epiduralography in 304 cases for the diagnosis of lumbar intervertebral disc protrusion. The radiopaque contrast media was injected into the epidural space and then X-rays were taken of the 304 cases, 273 cases received surgical intervention. Two hundred and seventy positive epidural X-ray, all were confirmed to have protruded or ruptured intervertebral disc at surgery. Three cases had negative epiduralgram preoperatively, no disc protrusion revealed at operation. Thus the accuracy of this technique in diagnosis of intervertebral disc protrusion was L 100%. The findings of positive epidural X-ray may be classified into 5 categories: (1) Lateral filling defect (21.2%), (2) Irregular filling defect near the center (0.7%), (3) Complete block of epidural space (35.6%), (4) Incomplete block of epidural space (27.4%), and (5) Unilateral block of epidural space (15.1%).

Humans↗
PubMed1988

Large-scale resolution of gossypol enantiomers for biological evaluation.

Gossypol has been resolved into its pure optical isomers by conversion into the Schiff's base derivative of (+)-phenylalanine methyl ester, normal or reverse phase chromatography and hydrolysis. Forty grams of pure (-)-gossypol has been prepared in a micronised form for assessment of its antifertility and toxicological effects.

Administration, Oral↗
PubMed1988

Isolation of (-)-gossypol from natural plant.

(-)-Gossypol has been isolated from cottonseed of G. barbadense L. Three Gossypium species were studied for the isolation. The study has also revealed a correlation between the optical activity of gossypol isolated and the species of cottonseed used. Gossypol isolated from the species G. barbadense is always found to be levorotatory caused by an excess of (-)-gossypol, whereas that from the species G. hirsutum is always dextrorotatory caused by an excess of (+)-gossypol. Results of most samples (cultivars) showed that optical purity of gossypol isolated from G. barbadense varied from 10-25%, while that from G. hirsutum varied from 10-20%. This is the first report of (-)-gossypol occurring naturally.

Chromatography, High Pressure Liquid↗