Biomedical subjects
Publications and source records attributed to J Lin.
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Pituitary cells from six pigs, 180-200 days of age, were studied in primary culture to determine if growth hormone releasing factor (GRF) affects long form leptin receptor (Ob-Rl) expression. On Day 4 of culture, 10(5) live cells per well were challenged with either 0, 10(-6), 10(-7) or 10(-8)M [Ala15]-hGRF-(1-29)NH(2) (3 wells per treatment per pig). Secretion of growth hormone (GH) into the media and pituitary Ob-Rl mRNA expression were determined at 4 h after treatment. Media were analyzed for GH by radioimmunoassay, and total RNA was isolated from cells for determination of Ob-Rl expression by semi quantitative reverse transcription PCR. Basal GH concentration was 32+/-2 ng per 10(5) cells per well (n=18 wells) for 4 h. Relative to control at 4 h, 10(-6),10(-7) and 10(-8)M GRF increased (P<0.01) GH secretion by 151, 129 and 120%, but decreased (P<0.05) Ob-Rl expression by 32, 50 and 38%, respectively. These results indicate that GRF directly modulates Ob-Rl expression at the level of the pituitary, and thereby playing a role in regulating pituitary sensitivity to leptin.
Polymorphism of HLA-DRB1, DQB1 and DPB1 was revealed with a sequencing-based typing (SBT) method in unrelated healthy volunteers from the Naxi ethnic group. Among the 43 DRB1 alleles detected, the most common allele was DRB1*12021 with a frequency of 17%, followed by DRB1*08032, DRB1*09012 and DRB1*1404 with frequencies of 8.5%, 7.4% and 7.4%, respectively. Among 23 DQB1 alleles detected, the most frequent DQB1 allele was DQB1*03011/0309 (21.9%), followed by DQB1*0502 (16.4%) and DQB1*05031 (9.6%). For the DPB1 locus, the most common alleles were DPB1*0501 (25.5%), DPB1*0402 (14.6%) and DPB1*02012 (12.0%). The most common DRB1-DQB1-DPB1 haplotype was DRB1*1404-DQB1*05031-DPB1*0402 with a frequency of 5.26%, followed by the DRB1*08032-DQB1*06011-DPB1*1301 (3.51%). The distribution characteristics of the HLA class II alleles revealed that the Naxi ethnic group belonged to the Southern group of Chinese.
A novel DPB1 allele (DPB1*9301) has been identified in an individual from the Lahu ethnic minority of China. Its sequence was confirmed by sequencing the PCR products and clones. This allele differs from DPB1*0601, *1701 and *3701 by two nucleotides in each, and results in amino acids substitution.
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Bulb of Fritillaria cirrhosa is an important traditional Chinese herbal medicine. According to the Chinese Pharmacopoeia (1995), it is commonly used as an antitussive and expectorant. Many young bulbs from species of Fritillaria are similar to those of F. cirrhosa, but they are different in price and quality. Therefore, there are many young bulbs from species of Fritillaria that could fake those of F. cirrhosa on the commercial market. The coding region of 5S-rRNA is highly conserved in higher eukaryotes. The 5S-rRNA spacer region sequences of F. thunbergii, F. pallidiflora, F. ussuriensi, F. delavayi, F.cirrhosa, F. anhuiensis, F. puqiensis were cloned by PCR with a pair of primers located within the conserved coding region. Based on sequences analyses of the 5S-rRNA spacer region from the 7 species, a specific sequence was found in F. cirrhosa. A pair of specific primers was designed for differentiating the bulbs of F. cirrhosa from each other by PCR. This result indicated that the method is rapid, more accurate and applicable in identification of the bulbs of F. cirrhosa at the DNA level.
The mechanism by which nitric oxide (NO)-dependent cytotoxicity acts against Toxoplasma gondii tachyzoites is poorly understood. An NO donor, sodium nitroprusside (SNP), was used to induce death in T. gondii tachyzoites in vitro as a model for investigating (i) whether NO is capable of inducing apoptosis-like death in tachyzoites and (ii) whether a calcium signal transduction pathway is involved. Exposure to 2 mM SNP resulted in a pattern of tachyzoite death that shares many features with metazoan apoptosis and it may involve a calcium signal transduction pathway. Motility and cell survival in these parasites showed a gradual decline with increasing levels of SNP. Features common to metazoan apoptosis are observed after exposure to 2 mM SNP. Ethylene glycol bis-(beta-aminoethyl ether)-N,N,N',N'-tetra-acetic acid (EGTA), Verapamil and bis-(o-aminophenoxy) ethane-N,N,N',N'-tetra-acetic acid/acetoxymethyl ester (BAPTA/AM) partially increased the cell survival concomitant with decreased [Ca2+]i in cells exposed to SNP. An NO scavenger (N-acetylcysteine), the analogue of SNP (devoid of NO), inhibited the rate of apoptosis after SNP treatment compared with SNP treatment without scavenger, but alone did not induce apoptosis. Taken together, the results indicate that SNP is capable of inducing apoptosis in T. gondii tachyzoites via a calcium signal transduction pathway.
The membrane bioreactor (MBR) system has become more and more attractive in the field of wastewater treatment. It is particularly attractive in situations where long solids retention times are required, such as nitrifying bacteria, and physical retention critical to achieving more efficiency for biological degradation of pollutant. Although it is a new technology, the MBR process has been applied for industrial wastewater treatment for only the past decade. The opto-electronic industry, developed very fast over the past decade in the world, is high technology manufacturing. The treatment of the opto-electronic industrial wastewater containing a significant quantity of organic nitrogen compounds with a ratio over 95% in organic nitrogen (Org-N) to total nitrogen (T-N) is very difficult to meet the discharge limits. This research is mainly to discuss the treatment capacity of high-strength organic nitrogen wastewater, and to investigate the capabilities of the MBR process. A 5 m3/day capacity of MBR pilot plant consisted of anoxic, aerobic and membrane bioreactor was installed for evaluation. The operation was continued for 150 days. Over the whole experimental period, a satisfactory organic removal performance was achieved. The COD could be removed with an average of over 94.5%. For TOC and BOD5 items, the average removal efficiencies were 96.3 and 97.6%, respectively. The nitrification and denitrification was also successfully achieved. Furthermore, the effluent did not contain any suspended solids. Only a small concentration of ammonia nitrogen was found in the effluent. The stable effluent quality and satisfactory removal performance mentioned above were ensured by the efficient interception performance of the membrane device incorporated within the biological reactor. The MBR system shows promise as a means of treating very high organic nitrogen wastewater without dilution. The effluent of TKN, NOx-N and COD can fall below 20 mg/L, 30 mg/L and 50 mg/L.
We present a prototype of a new database tool, GeneCensus, which focuses on comparing genomes globally, in terms of the collective properties of many genes, rather than in terms of the attributes of a single gene (e.g. sequence similarity for a particular ortholog). The comparisons are presented in a visual fashion over the web at GeneCensus.org. The system concentrates on two types of comparisons: (i) trees based on the sharing of generalized protein families between genomes, and (ii) whole pathway analysis in terms of activity levels. For the trees, we have developed a module (TreeViewer) that clusters genomes in terms of the folds, superfamilies or orthologs--all can be considered as generalized 'families' or 'protein parts'--they share, and compares the resulting trees side-by-side with those built from sequence similarity of individual genes (e.g. a traditional tree built on ribosomal similarity). We also include comparisons to trees built on whole-genome dinucleotide or codon composition. For pathway comparisons, we have implemented a module (PathwayPainter) that graphically depicts, in selected metabolic pathways, the fluxes or expression levels of the associated enzymes (i.e. generalized 'activities'). One can, consequently, compare organisms (and organism states) in terms of representations of these systemic quantities. Develop ment of this module involved compiling, calculating and standardizing flux and expression information from many different sources. We illustrate pathway analysis for enzymes involved in central metabolism. We are able to show that, to some degree, flux and expression fluctuations have characteristic values in different sections of the central metabolism and that control points in this system (e.g. hexokinase, pyruvate kinase, phosphofructokinase, isocitrate dehydrogenase and citric synthase) tend to be especially variable in flux and expression. Both the TreeViewer and PathwayPainter modules connect to other information sources related to individual-gene or organism properties (e.g. a single-gene structural annotation viewer).
BACKGROUND: PD is largely a sporadic condition of unknown etiology, but specific inherited mutations are a cause of PD. OBJECTIVE: To describe a large, multi-incident Amish pedigree with PD. METHODS: Case ascertainment, calculation of population prevalence, and calculation of kinship coefficients (a measure of relatedness between two individuals) for affecteds and subjects in a large kindred with PD were conducted. Sequencing of genes with known mutations sufficient to cause PD and marker-by-marker haplotype analysis in chromosomal regions flanking previously described genes with known mutations were performed. RESULTS: The authors have examined 113 members of this pedigree and classified 67 as normal (no evidence of PD), 17 as clinically definite PD, 6 as clinically probable PD, and 23 as clinically possible PD. The mean age at onset of the clinically definite subjects was 56.7 years. The phenotype in this family is typical of idiopathic PD, including rest tremor, rigidity, bradykinesia, postural instability, and response to levodopa. In addition, dementia occurred in six of the clinically definite subjects, and many subjects experienced levodopa-related motor complications including wearing off and dopa-induced dyskinesias. In the index Amish community, a minimum prevalence of PD in the population 40 years and older of 552/100,000 was calculated. The mean kinship coefficient in the subjects with PD and those with PD by history (0.036) was higher (p = 0.007) than in a group of age-matched normal Amish control subjects (0.016), providing evidence that PD is inherited in this family. Sequence analysis did not detect any mutations in known PD genes. No single haplotype cosegregates with the disease in any of the chromosomal regions previously found to be linked to PD, and no marker in these regions exhibits increased homozygosity among definite PD cases. CONCLUSIONS: PD in this community is more common than in the general population, and this increased prevalence may be due in part to a novel gene(s).
AIMS/HYPOTHESIS: Vitronectin-receptor-type integrins (alpha(v) beta(3) and alpha(v) beta(5)) are thought to be involved in the selective ablation of tumorigenic and other pathologic angiogenesis. Specifically, it has been shown that ligation inhibition of the alpha(v)-type integrins with cyclic penta-peptid peptide inhibits proliferative retinopathy by almost 80 % in a hypoxia-induced mouse model. METHODS: On the basis of growth factor and integrin expression dynamics in this model, secondary intervention approaches with cyclic RGDfV peptide were investigated. RESULTS: alpha(v)-integrin expression started immediately after induction of hypoxia (at postnatal day 12, p12) and persisted only during the initial period of neovascularization (until day p14). Vascular endothelial growth factor (VEGF) expression started at high values immediately after return of the mice into room air, and dropped rapidly to low values beyond day 13. In contrast, basic fibroblast growth factor (bFGF) was predominantly expressed during the phase of maximum angiogenesis which was noted between day p17 and 19. Based on these findings, cyclic penta peptide was administered subcutaneously at varying doses (2-20 microg/kg/day) for 5 days beginning either at day p14 (early intervention) or at day p17 (late intervention). Early secondary intervention showed a dose-dependent reduction of new vessels with maximum inhibition of 57 % (control 68.08 +/- 3.21 nuclei/section compared with RGDfV-treated 29.35 +/- 2.39 nuclei/section; p < 0.0001), whereas late secondary intervention had no effect. CONCLUSION/HYPOTHESIS: These data indicate that angiogenesis-related alpha(v)-integrin expression is VEGF- rather than bFGF-dependent, and the efficacy of cyclic penta-peptid (RGDfV)-treatment in proliferative retinopathy is only effective as long as the alpha(v)-integrin target is prominently expressed.
Aqueous and methanolic extracts of several medicinal plants, Psidium guajava (leaves), Aristea spp., Iridaceae family (stem), Bridelia micrantha (bark) and Eleutherina bulbosa (bulb), used by Zulu traditional healers were evaluated for anti-diarrhoeal activity against different experimental models of diarrhoea in rats as well as for anti-microbial activity against different pathogenic microorganisms that cause diarrhoea. The methanolic extract of P. guajava (leaves) was the only agent showing significant inhibitory activities against the growths of Salmonella spp. (two isolates), Shigella spp. (S. flexneri, S. virchow and S. dysenteriae) and enteropathogenic Escherechia coli (two isolates). The methanolic extract of B. micrantha (Bark) demonstrated weak inhibitory activities against S. flexneri and S. plesiomonas. Based on the results in experimental rat models, there were significant reductions in faecal output and frequency of droppings when plant extracts were administered compared with castor-oil treated rats. All plant extracts also significantly retarded the propulsion of charcoal meal and significantly inhibited the PGE(2)-induced enteropooling. The results have confirmed the effectiveness of all these Zulu medicinal plants as anti-diarrhoeal agents.
A novel DQB1 allele, DQB1*05022, has been identified from an individual of the Jing ethnic group in South-west China. The sequence was confirmed by cloning and sequencing. The allele differs from DQB1*05021 at codon 47 (TAC to TAT) and from DQB1*05031 at codon 57 (GAC to AGC).
A sequencing-based typing of the HLA-DPB1 gene was carried out in 51 unrelated healthy individuals from the Yunnan Pumi ethnic minority. A total of 18 DPB1 alleles, in which DPB1*0501 (52.0%) and DPB1*0402 (15.7%) greatly predominated, were found, of which alleles DPB1*20011, 2201, 3601, 3701, 3801, 4901, 5001 and 8001 were recorded for the first time in the Chinese population. This may be because the typing methods used in previous genotyping of Chinese populations were of lower sensitivity than that used in our study. A dendrogram constructed by the maximum likelihood method showed that the Pumi ethnic minority belongs to the Asian/Australasian cluster and has the closest relationship to Trobriander, implying an unusual relationship between Australasian and South China populations. However, the Yi ethnic minority, which also comes from the ancient Qiang, did not show a very close relationship with the Pumi. This is probably because the Pumi were historically assimilated by local south-west China populations.
A new DRB1 allele, DRB1*0902, has been identified in an individual of the Jing ethnic minority. Its sequence was confirmed by sequencing of PCR products and clones. This allele differed by three nucleotides from DRB1*09012 at positions 157, 161 and 166, and resulted in amino acid motif substitution from VAES to DAEY.
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This study determined what physiotherapists in Durban, South Africa know about human immunodeficiency virus (HIV)/acquired immune deficiency syndrome (AIDS), their attitudes towards patients and how they cope as individuals. Data were collected using a validated questionnaire. One-hundred-and-fourteen physiotherapists in Durban hospitals participated in the study. Seventy-two per cent of the questionnaires met the criteria for analysis. Ninety per cent of the participants believed that they knew about HIV/AIDS, but only 78% could identify all viral transmission modes. Of the 38 physiotherapists who believed that they knew the stages of an HIV infection, only 11% actually knew the stages, 28% could not explain them and 61% were vaguely aware. Fifty-six per cent of the respondents had treated patients who had died from HIV/AIDS. Only 38% of physiotherapists were completely at ease when treating HIV/AIDS patients despite the fact that 98% believed that physiotherapy was an integral component of the management of an AIDS patient. Fifty-one per cent of the respondents were unaware of support structures provided by their employers. The authors conclude that the perceptions of physiotherapists about their knowledge about HIV/AIDS do not stand up to scrutiny. Significantly more attention should be paid to the development, implementation and evaluation of the effectiveness of educational programmes on HIV/AIDS for physiotherapists in the workplace.
The effects of immunization with the ferric citrate receptor FecA on antibody responses and on experimentally induced mastitis following intramammary challenge were investigated. Twenty-one cows were assigned to seven blocks of three cows based on expected parturition. Cows within block were randomly assigned to one of three treatments: 1) FecA immunization, 2) Escherichia coli J5 immunization, and 3) unimmunized controls. Challenge was by infusion of approximately 60 cfu of E. coli 727 into one uninfected mammary gland between 13 and 31 d after parturition. Cows within block were challenged on the same day. Cows immunized with FecA had higher immunoglobulin (Ig)G titers against FecA in serum and in mammary secretions at calving, immediately before challenge, and 7 d after challenge than did cows immunized with E. coli J5 or control cows. Immunization with FecA also increased IgG titers against whole-cell E. coli 727 in serum and in mammary secretions at calving. Serum IgM titers against FecA were higher in FecA immunized cows than in other treatment groups immediately before challenge. Bacterial counts in milk, duration of bacterial isolation in milk, rectal temperature, and milk somatic cell counts following intramammary challenge were similar among treatments. Milk production and dry matter intake did not differ among treatments. The ferric citrate receptor FecA was immunogenic in cows, but immunization had minimal effect on the clinical severity of experimentally induced E. coli mastitis.