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91.
da Silva-Vasconcelos A Kató MY Mourão EN de Souza RT Lacerda RN Sibajev A Tsouris P Póvoa MM Momen H Rosa-Freitas MG 《Memórias do Instituto Oswaldo Cruz》2002,97(2):151-161
The epidemiology of the transmission of malaria parasites varies ecologically. To observe some entomological aspects of the malaria transmission in an urban environment, a longitudinal survey of anopheline fauna was performed in Boa Vista, Roraima, Brazil. A total of 7,263 anophelines was collected in human bait at 13 de Setembro and Caran? districts: Anopheles albitarsis sensu lato (82.8%), An. darlingi (10.3%), An. braziliensis (5.5%), An. peryassui (0.9%) and An. nuneztovari (0.5%). Nightly 12 h collections showed that An. albitarsis was actively biting throughout the night with peak activities at sunset and at midnight. An. darlingi bit during all night and did not demonstrate a defined biting peak. Highest biting indices, entomological inoculation rates and malaria cases were observed seasonally during the rainy season (April-November). Hourly collections showed host seek activity for all mosquitoes peaked during the first hour after sunset. An. darlingi showed the highest plasmodial malaria infection rate followed by An. albitarsis, An. braziliensis and An. nuneztovari (8.5%, 4.6%, 3% and 2.6%, respectively). An. albitarsis was the most frequently collected anopheline, presented the highest biting index and it was the second most frequently collected infected species infected with malaria parasites. An. albitarsis and An. darlingi respectively, are the primary vectors of malaria throughout Boa Vista. 相似文献
92.
DeHaven-Hudkins DL Cowan A Cortes Burgos L Daubert JD Cassel JA DeHaven RN Kehner GB Kumar V 《Life sciences》2002,71(23):2787-2796
Loperamide and three of its analogs were evaluated for their ability to inhibit binding to cloned human opioid receptor subtypes and to produce antipruritis and antinociception following local s.c. administration to rodents. All four compounds were fully efficacious agonists with affinities of 2 to 4 nM for the cloned human mu opioid receptor. Local s.c. injection of loperamide, ADL 01-0001 or ADL 01-0002 at the same site as the introduction of the pruritogenic compound 48/80 resulted in antipruritic activity in a mouse model of itch. Similarly, i.paw or i.pl. administration of compounds ADL 01-0001, ADL 01-0002 and ADL 01-0003 to inflamed paws caused potent antinociception, inhibiting late phase formalin-induced flinching, Freund's adjuvant-induced mechanical hyperalgesia and tape stripping-induced mechanical hyperalgesia. Loperamide and its analogs were efficacious in animal models of itch and inflammatory pain, and may have potential therapeutic utility as antipruritic and antihyperalgesic agents. 相似文献
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95.
Reduced-median-network analysis of complete mitochondrial DNA coding-region sequences for the major African, Asian, and European haplogroups 总被引:38,自引:0,他引:38 下载免费PDF全文
Herrnstadt C Elson JL Fahy E Preston G Turnbull DM Anderson C Ghosh SS Olefsky JM Beal MF Davis RE Howell N 《American journal of human genetics》2002,70(5):1152-1171
The evolution of the human mitochondrial genome is characterized by the emergence of ethnically distinct lineages or haplogroups. Nine European, seven Asian (including Native American), and three African mitochondrial DNA (mtDNA) haplogroups have been identified previously on the basis of the presence or absence of a relatively small number of restriction-enzyme recognition sites or on the basis of nucleotide sequences of the D-loop region. We have used reduced-median-network approaches to analyze 560 complete European, Asian, and African mtDNA coding-region sequences from unrelated individuals to develop a more complete understanding of sequence diversity both within and between haplogroups. A total of 497 haplogroup-associated polymorphisms were identified, 323 (65%) of which were associated with one haplogroup and 174 (35%) of which were associated with two or more haplogroups. Approximately one-half of these polymorphisms are reported for the first time here. Our results confirm and substantially extend the phylogenetic relationships among mitochondrial genomes described elsewhere from the major human ethnic groups. Another important result is that there were numerous instances both of parallel mutations at the same site and of reversion (i.e., homoplasy). It is likely that homoplasy in the coding region will confound evolutionary analysis of small sequence sets. By a linkage-disequilibrium approach, additional evidence for the absence of human mtDNA recombination is presented here. 相似文献
96.
97.
Maize HSP101 plays important roles in both induced and basal thermotolerance and primary root growth 总被引:14,自引:0,他引:14 下载免费PDF全文
Nieto-Sotelo J Martínez LM Ponce G Cassab GI Alagón A Meeley RB Ribaut JM Yang R 《The Plant cell》2002,14(7):1621-1633
HSP101 belongs to the ClpB protein subfamily whose members promote the renaturation of protein aggregates and are essential for the induction of thermotolerance. We found that maize HSP101 accumulated in mature kernels in the absence of heat stress. At optimal temperatures, HSP101 disappeared within the first 3 days after imbibition, although its levels increased in response to heat shock. In embryonic cells, HSP101 concentrated in the nucleus and in some nucleoli. Hsp101 maps near the umc132 and npi280 markers on chromosome 6. Five maize hsp101-m-::Mu1 alleles were isolated. Mutants were null for HSP101 and defective in both induced and basal thermotolerance. Moreover, during the first 3 days after imbibition, primary roots grew faster in the mutants at optimal temperature. Thus, HSP101 is a nucleus-localized protein that, in addition to its role in thermotolerance, negatively influences the growth rate of the primary root. HSP101 is dispensable for proper embryo and whole plant development in the absence of heat stress. 相似文献
98.
Lopes PA Viegas-Cresp AM Nunes AC Pinheiro T Marques C Santos MC Mathias Mde L 《Biological trace element research》2002,85(3):227-239
The influence of age, gender and sexual activity on both hepatic levels of some trace elements (Fe, Cu, Zn, Mn, Se) and the
activities of glutathione-S-transferase (GST) and superoxide dismutase (SOD) was investigated in Wood mice (Apodemus sylvaticus) and Algerian mice (Mus spretus). Animals were taken from a riverside community of an unpolluted area of central Portugal. Adult A. sylvaticus presented the highest hepatic mean concentrations of Cu and Mn, whereas adult M. spretus had the highest Fe concentration in the liver. Moreover, an influence of age on the contents of Fe, Zn, and Mn has been observed
in A. sylvaticus, whereas in M. spretus an influence of gender and sexual activity was only detected on Zn levels. In contrast, enzyme activities were not influenced
by the studied variables, despite a tendency for an increase in SOD activity in sexually active M. spretus. GST activity was species dependent, whereas SOD activity was similar between species. These findings were analyzed regarding
the relationship of both essential trace elements and the two antioxidant enzymes with physiological and metabolic pathways
related to life cycles in the two species of mice. Results enhanced the understanding of A. sylvaticus and M. spretus as biological models, allowing their future use as bioindicators of environmental toxicity. 相似文献
99.
Stoicheiometric analysis of metabolic pathways provides a systematic way of determining which metabolite concentrations are subject to constraints, information that may otherwise be very difficult to recognize in a large branched pathway. The procedure involves representing the pathway structure in the form of a matrix and then carrying out row operations to convert the matrix into "row echelon form": this is a form in which as many as possible of the elements on the main diagonal are non-zero, and all of the elements below the main diagonal are zero. If exactly the same operations are carried out on a unit matrix of order equal to the number of intermediate metabolites in the pathway, the resulting matrix allows the stoicheiometric constraints to be read off directly. 相似文献
100.
Genoud S Lappe-Siefke C Goebbels S Radtke F Aguet M Scherer SS Suter U Nave KA Mantei N 《The Journal of cell biology》2002,158(4):709-718
We have selectively inhibited Notch1 signaling in oligodendrocyte precursors (OPCs) using the Cre/loxP system in transgenic mice to investigate the role of Notch1 in oligodendrocyte (OL) development and differentiation. Early development of OPCs appeared normal in the spinal cord. However, at embryonic day 17.5, premature OL differentiation was observed and ectopic immature OLs were present in the gray matter. At birth, OL apoptosis was strongly increased in Notch1 mutant animals. Premature OL differentiation was also observed in the cerebrum, indicating that Notch1 is required for the correct spatial and temporal regulation of OL differentiation in various regions of the central nervous system. These findings establish a widespread function of Notch1 in the late steps of mammalian OPC development in vivo. 相似文献