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1.  Gastric bypass surgery, but not caloric restriction, decreases dipeptidyl peptidase-4 activity in obese patients with type 2 diabetes 
Diabetes, obesity & metabolism  2011;13(4):378-381.
The mechanism by which incretins and their effect on insulin secretion increase markedly following gastric bypass (GBP) surgery is not fully elucidated. We hypothesized that a decrease in the activity of dipeptidyl peptidase-4 (DPP-4), the enzyme which inactivates incretins, may explain the rise in incretin levels post-GBP. Fasting plasma DPP-4 activity was measured after 10-kg equivalent weight loss by GBP (n = 16) or by caloric restriction (CR, n = 14) in obese patients with type 2 diabetes. DPP-4 activity decreased after GBP by 11.6% (p = 0.01), but not after CR. The increased peak glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) response to oral glucose after GBP did not correlate with DPP-4 activity. The decrease in fasting plasma DPP-4 activity after GBP occurred by a mechanism independent of weight loss and did not relate to change in incretin concentrations. Whether the change in DPP-4 activity contributes to improved diabetes control after GBP remains therefore to be determined.
doi:10.1111/j.1463-1326.2011.01358.x
PMCID: PMC3656488  PMID: 21210936
dipeptidyl peptidase inhibitor; GLP-1; gastric bypass; weight loss
2.  An MPS-BNS Mixed Strategy Based on Game Theory for Wireless Mesh Networks 
The Scientific World Journal  2013;2013:936536.
To achieve a valid effect of wireless mesh networks against selfish nodes and selfish behaviors in the packets forwarding, an approach named mixed MPS-BNS strategy is proposed in this paper. The proposed strategy is based on the Maximum Payoff Strategy (MPS) and the Best Neighbor Strategy (BNS). In this strategy, every node plays a packet forwarding game with its neighbors and records the total payoff of the game. After one round of play, each player chooses the MPS or BNS strategy for certain probabilities and updates the strategy accordingly. In MPS strategy, each node chooses a strategy that will get the maximum payoff according to its neighbor's strategy. In BNS strategy, each node follows the strategy of its neighbor with the maximum total payoff and then enters the next round of play. The simulation analysis has shown that MPS-BNS strategy is able to evolve to the maximum expected level of average payoff with faster speed than the pure BNS strategy, especially in the packets forwarding beginning with a low cooperation level. It is concluded that MPS-BNS strategy is effective in fighting against selfishness in different levels and can achieve a preferable performance.
doi:10.1155/2013/936536
PMCID: PMC3562672  PMID: 23401672
3.  Frequency of formation of chimeric molecules as a consequence of PCR coamplification of 16S rRNA genes from mixed bacterial genomes. 
Applied and Environmental Microbiology  1997;63(12):4645-4650.
PCR is routinely used in amplification and cloning of rRNA genes from environmental DNA samples for studies of microbial community structure and identification of novel organisms. There have been concerns about generation of chimeric sequences as a consequence of PCR coamplification of highly conserved genes, because such sequences may lead to reports of nonexistent organisms. To quantify the frequency of chimeric molecule formation, mixed genomic DNAs from eight actinomycete species whose 16S rRNA sequences had been determined were used for PCR coamplification of 16S rRNA genes. A large number of cloned 16S ribosomal DNAs were examined by sequence analysis, and chimeric molecules were identified by multiple-sequence alignment with reference species. Here, we report that the level of occurrence of chimeric sequences after 30 cycles of PCR amplification was 32%. We also show that PCR-induced chimeras were formed between different rRNA gene copies from the same organism. Because of the wide use of PCR for direct isolation of 16S rRNA sequences from environmental DNA to assess microbial diversity, the extent of chimeric molecule formation deserves serious attention.
PMCID: PMC168786  PMID: 9406382
4.  Rapid differentiation of bacterial species with multiple probes of different lengths in a single slot blot hybridization. 
Applied and Environmental Microbiology  1995;61(12):4269-4273.
We describe a highly efficient method for dot and slot blot hybridizations with multiple oligonucleotide probes for high throughput identification of organisms and studies of microbial community structures. Several probes with distinct specificities were designed to have the same melting temperature but unique lengths by adding different numbers of nonspecific nucleotides to one end. All of the probes were mixed, labelled with 32P, and hybridized to one piece of membrane on which genes coding for 16S rRNAs from different bacterial species had been immobilized. After hybridization, the bound probes were eluted and resolved on a denaturing polyacrylamide gel and the identities of the genes coding for 16S rRNAs were read from an autoradiograph of the gel. The results from the application of this technique to pure actinomycete cultures are reported here.
PMCID: PMC167738  PMID: 8534094
5.  A retrospective cohort study of leukemia and other cancers in benzene workers 
A retrospective cohort study was carried out in 1982–1983 among 28,460 benzene-exposed workers (15,643 males, 12,817 females) from 233 factories and 28,257 control workers (16,621 males, 12,366 females) from 83 factories in 12 large cities in China. All-cause mortality was significantly higher among the exposed (265.46/100,000 person-years) than among the unexposed (139.06/100,000 person-years), as was mortality from all malignant neoplasms (123.21/100,000 versus 54.7/100,000, respectively). For certain cancers, increased mortality was noted among benzene-exposed males in comparison with that among unexposed males; the standardized mortality ratios (SMR) were elevated for leukemia (SMR = 5.74), lung cancer (SMR = 2.31), primary hepatocarcinoma (SMR = 1.12), and stomach cancer (SMR = 1.22). For females only leukemia occurred in excess among the exposed. Risk of leukemia rose as duration to exposure to benzene increased up to 15 years, and then declined with additional years of exposure. Leukemia occurred among some workers with as little as 6 to 10 ppm average exposure and 50 ppm-years (or possibly less) cumulative lifetime exposure (based on all available measurements for the exposed work units). Among the 30 leukemia cases identified in the exposed cohort, the proportion of subjects with acute lymphocytic leukemia was substantially lower and the proportion with acute nonlymphocytic leukemias was higher than in the general population. During 1972 to 1981, the annual incidence of leukemia ranged from 5.83 to 28.33 per 100,000 with higher rates occurring in the interval 1977 to 1981 than in the earlier years of the study period. Future studies should evaluate more precisely the relationship between exposure levels, job title, and development of leukemia among cases and noncases within the exposed cohort.
PMCID: PMC1568128  PMID: 2792042
6.  Leukaemia in benzene workers: a retrospective cohort study. 
A retrospective cohort study was conducted in 233 benzene factories and 83 control factories in 12 cities in China. The benzene cohort and the control cohort consisted of 28,460 benzene exposed workers (178,556 person-years in 1972-81) and 28,257 control workers (199,201 person-years). Thirty cases of leukaemia (25 dead and 5 alive) were detected in the former and four cases (all dead) in the latter. The leukaemia mortality rate was 14/100,000 person-years in the benzene cohort and 2/100,000 person-years in the control cohort; the standardized mortality ratio was 5.74 (p less than 0.01 by U test). The average latency of benzene leukaemia was 11.4 years. Most (76.6%) cases of benzene leukaemia were of the acute type. The mortality due to benzene leukaemia was high in organic synthesis plants followed by painting and rubber synthesis industries. The concentration of benzene to which patients with a leukaemia were exposed ranged from 10 to 1000 mg/m3 (mostly from 50 to 500 mg/m3). Of the 25 cases of leukaemia, seven had a history of chronic benzene poisoning before the leukaemia developed.
PMCID: PMC1007793  PMID: 3814544

Results 1-6 (6)