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41.
Several reports suggest that the glutathione-S-transferase (GST) family of enzymes is involved in a variety of cancers, due to their carcinogen-detoxification properties. A polymorphism in codon 105 of the pi variant (GSTP1 I105V), which affects the enzymatic activity of the enzyme, has been linked to the incidence of cancers from different organs. However, the published data in prostate cancer (PCa) is controversial. Some studies report an association with the GSTP1 I105V polymorphism and sporadic PCa, whereas other studies report no association. Recently, one study showed a positive correlation between the GSTP1 I105V polymorphism and familial PCa in a Japanese population. In the present study, we assessed the correlation of the GSTP1 I105V polymorphism with familial and sporadic PCa in an American population. We analyzed DNA samples from 438 patients with familial PCa, 499 patients with sporadic PCa, and 510 controls. We found no significant association between the GSTP1 I105V polymorphism and familial or sporadic PCa when compared to the control group [odds ratio (OR) =1.0 (0.74-1.37); P=0.58]. Moreover, no association was found after stratification for age of diagnosis, Gleason grade, or lymph node involvement [OR =0.84 (0.65-1.09), P=0.37]. These data indicate that there is no associated risk for sporadic or familial PCa in American families containing the GSTP1 I105V polymorphism.  相似文献   
42.
PHACE syndrome is the term applied to the association of posterior fossa brain abnormalities, hemangiomas, arterial anomalies in the cranial vasculature, coarctation of the aorta/cardiac defects, and eye abnormalities. An overlap with the sternal malformation/vascular dysplasia association has been described. We report an adult patient with complete manifestations of both conditions. As an adult she has demonstrated resolution of the hemangiomas and only mild intellectual difficulties.  相似文献   
43.
Isolates of Borrelia turicatae, Borrelia parkeri, and the Florida canine borrelia (FCB) were examined to further phylogenetically characterize the identities of these spirochetes in the United States. DNA sequences of four chromosomal loci (the 16S rRNA gene, flaB, gyrB, and glpQ) were determined for eight isolates of B. turicatae and six isolates of B. parkeri, which grouped the spirochetes into two distinct but closely related taxa (>98% sequence identity) separate from Borrelia hermsii. The FCB was clearly separated with the group identified as B. turicatae, confirming this bacterium as a relapsing fever spirochete. Therefore, the potential for tick-borne relapsing fever in humans and other animals exists in Florida and future efforts are needed to determine the enzootic hosts and distribution of this spirochete in the southeastern United States. Analysis of plasmids demonstrated both linear and circular forms in B. turicatae but only linear plasmids in B. parkeri, which should be of interest to investigators concerned with plasmid diversity and evolution within this group of spirochetes.  相似文献   
44.
Infanticide is a reproductive strategy found in many mammals, especially rodents. The proportion of male and female house mice (Mus domesticus) that are either infanticidal or noninfanticidal is strain specific and varies widely from stock to stock. Male house mice also show strain-specific variation in the behavioral mechanisms that inhibit infanticidal individuals from killing their own offspring. The adult offspring generated from reciprocally crossed CF-1 and Wild stock house mice were tested for their behavior toward newborn pups. In male CF-1xWild hybrids, the proportion of infanticidal and noninfanticidal males matched with their maternal phenotype, whereas female CF-1xWild hybrids exhibited a proportion of behaviors typical of the CF-1 phenotype, regardless of their mother's genotype. Our results suggest three conclusions: first, that infanticide is a highly labile and heritable behavior in both sexes; second, that there is a sex difference in the genetic substrate that regulates the inheritance of infanticidal behavior; and third, that selection pressures in male mice may operate independently on the mechanisms that promote spontaneous infanticidal behavior versus the mechanisms that inhibit infanticide.  相似文献   
45.
Summary The fibre type composition of the avian adductor profundus (AP) muscle which is composed of a thick white posterior part (Post. AP) and a thin red anterior part (Ant. AP) was investigated. Using the histochemical ATPase technique, monoclonal antibody analysis of myosin and C-protein isoforms, and electrophoretic and peptide mapping analyses of myosin, we have established that the Post. AP is composed of essentially pure slow tonic fibres similar to those of the anterior latissimus dorsi muscle (ALD). The Ant. AP, on the other hand, is shown to contain a mixture of slow and fast fibres, the latter giving immunocytochemical reactions atypical of the fast fibres. The larger size of the Post. AP in comparison with the ALD muscle should provide significantly more tissue for biochemical studies of tonic fibres than was previously available.  相似文献   
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48.
The human T-cell leukemia virus type 1 (HTLV-1) and human immunodeficiency virus type 1 (HIV-1) retroviruses are two evolutionary distinct human pathogens. HTLV-1 is the etiologic agent of two diverse diseases: adult T-cell leukemia/lymphoma, as well as the neurologic disorder tropical spastic paraparesis/HTLV-1-associated myelopathy. HTLV-1 is the only retrovirus known to be the etiologic agent of human cancer. HTLV-2, the other known oncovirus, is not apparently associated with human cancer. While HTLV-1 transforms T-cells in vitro, HIV kills CD4+ T-cells and is the etiological agent of human acquired immunodeficiency syndrome, characterized by a progressive loss of CD4+ cells, weakening of the immune system, and susceptibility to opportunistic infections and cancer. HTLV-1 and HIV-1 both cause lifelong infections, which suggests that they have evolved mechanism(s) to evade detection by the host's immune response; particularly to evade cytotoxic T-lymphocytes, which play a major role in cellular immunity against viruses and will be the focus of this review.  相似文献   
49.
Bioweapons are most often designed for delivery to the lung, although this route is not the usual portal of entry for many of the pathogens in the natural environment. Vaccines and therapeutics that are efficacious for natural routes of infection may not be effective against the pulmonary route. Pulmonary models are needed to investigate the importance of specific bacterial genes in virulence, to identify components of the host immune system that are important in providing innate and acquired protection, and for testing diagnostic and therapeutic strategies. This report describes the characteristics of host and Bacillus anthracis interactions in a murine pulmonary-infection model. The infective dose varied depending on the route and method of inoculation. The germination process in the lung began within 1 h of inoculation into the lung, although growth within the lung was limited. B. anthracis was found in the lung-associated lymph nodes approximately 5 h after infection. Minimal pneumonitis was associated with the lung infection, but significant systemic pathology was noted after dissemination. Infected mice typically succumbed to infection approximately 3 to 4 days after inoculation. The 50% lethal doses differed among inbred strains of mice, but within a given mouse strain, neither the age nor the sex of the mice influenced susceptibility to B. anthracis.  相似文献   
50.
Because of the essential role of transporter associated with antigen processing (TAP1 or TAP2) molecule in antigen processing, the implication of its polymorphism as a factor involved in human diseases and the possible genetic variation at this locus among ethnically diverse populations, we underwent a study to analyze the full extent of TAP1 polymorphism in an indigenous Zimbabwean population (Shona ethnic group). Using single-stranded conformation polymorphism and DNA direct sequencing procedures, we detected the presence of 11 nucleotide sequence variations in the entire coding region of TAP1. Of these variants, eight are nonconservative substitutions with respect to amino acid composition and are located in a critical part of the protein that could modulate its function. Five new polymorphic sites were identified in exon 1 (codons 7 Pro --> Ser, 17 Gly --> Arg, 141 Val --> Val), exon 6 (codon 419 Gly --> Cys), and exon 7 (codon 487 Arg --> Arg). Significant differences were seen in the distribution of TAP1*0201 and TAP1*0401 alleles, and codon 333 (Ile --> Val) polymorphism among African and non-African populations. Thus, TAP1 polymorphism has evolved differently among populations presumably because of the evolutionary pressures generated by prevalent pathogens in these geographically distinct regions.  相似文献   
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