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61.
Obstruction of a Bjork-Shiley mitral valve prosthesis occurred in a 41 year old woman due to pannus tissue growing over the valve and impairing disc opening. The unusual intermittent nature of the obstruction was clearly demonstrated by Doppler ultrasound. The pannus was excised and the valve prosthesis replaced successfully with a Carpentier-Edwards xenograft. 相似文献
62.
Evidence consistent with horizontal transfer of the gene (emm12) encoding serotype M12 protein between group A and group G pathogenic streptococci.
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Human isolates of Lancefield group G streptococci harbor sequences homologous with the structural gene (emm) encoding M protein, a major virulence factor in Streptococcus pyogenes (a group A Streptococcus species). We used DNA-DNA hybridization, restriction endonuclease chromosomal profiling, and multilocus enzyme electrophoresis to examine genetic relationships between group A and group G streptococcal strains expressing homologous serologic type 12 M (M12) protein. All M12 group A strains studied had very similar restriction endonuclease genomic profiles and multilocus enzyme genotypes. In contrast, the restriction enzyme genomic profile and multilocus enzyme genotype of the M12 group G strain CS140 were strikingly different from those characterizing the M12 group A organisms. DNA-DNA hybridization studies revealed, on average, 57% genomic similarity between the M12 group A and group G strains. Taken together, our data demonstrate that a gene encoding M12 protein occurs in two highly divergent chromosomal backgrounds, a result suggesting that an episode of horizontal gene transfer and recombination has occurred between two streptococcal lineages. 相似文献
63.
Pregnancy outcome associated with natural family planning (NFP): scientific basis and experimental design for an international cohort study 总被引:1,自引:0,他引:1
J. L. Simpson R. H. Gray J. T. Queenan P. Mena A. Perez R. T. Kambic G. Tagliabue F. Pardo W. S. Stevenson M. Barbato V. H. Jennings M. J. Zinaman J. M. Spieler 《Advances in Contraception》1988,4(4):247-264
Although natural family planning (NFP) is a form of contraception without ostensible maternal risks (other than pregnancy), potential fetal risks could exist if aging gametes are involved in inadvertent fertilization. In the following report, we first review animal studies firmly establishing that aging sperm and aging oocytes (delayed fertilization) cause chromosomal abnormalities in mammals and other species. We next review human studies associating decreased coital frequency with trisomy and studies of NFP populations that generally show no increased frequency of anomalous offspring or spontaneous abortions. Our rationale for initiating an international cohort study is presented, along with the experimental design selected. Preliminary findings indicate that the experimental design chosen will indeed provide information allowing NFP safety to be assessed definitively.
Resumen Aunque la planificación familiar natural (PFN) es una forma de anticoncepción sin riesgos maternos ostensibles, (fuera del embarzo) podrían existir posibles riesgos fetales di gametos que están envejeciendo son inadvertidamente fertilizados. La primera revisión de estudios en animales establece firmemente que espermatozoides y oocytos en envejecimiento (fertilización tardía), causan anormalidades cromosómicas en mamíferos y otras especies. A continuación revisamos estudios en humanos que asocian la disminución de la frecuencia coital con trisomía, y estudios de poblaciones practicando PFN que generalmente no muestran aumento en la frecuencia de descendientes anormales o de abortos espontáneos. Presentamos nuestras razones para iniciar el estudio de una cohorte internactional ademas del diseño experimental elegido proveerá información alegando que la inocuidad de la PFN sea definitivamente valorada.
Resumé Bien que le planning familial naturel (PFN-NFP) soit une forme de contraception ne présentant pas de risques manifestes pour la mère (autres qu'une grossesse), il pourrait y avoir des risques potentiels pour le foetus si des gamètes âgés sont par inadvertance fécondés. Nous passons en revue tout d'abord des études effectuées sur des animaux, établissant fermement que le sperme veillissant et les oocytes vieillissants (fécondation retardée) provoquent des anomalies chromosomales chez les mammifères et d'autres espèces. Nous examinons ensuite des études sur des humains, qui associent diminution coitale et trisomie, et des études de populations pratiquant le PFN, qui ne révèlent généralement pas de fréquence accrue d'enfants anormaux ou d'avortements spontanés. Cette communication expose la raison pour laquelle nous avons entrepris une étude sur une cohorte internationale, ainsi que le concept d'expérimentation que nous avons choisi. Les constatations préliminaires indiquent que ce concept fournira véritablement des informations qui permettront d'évaluer de façon définitive la sécurité du PFN.相似文献
64.
65.
R.E. Ortega L.H. Riina T.A. Davenport L.T. Glickman R.L. Simpson K.M. Burger D. Hangan 《Wound repair and regeneration》2004,12(2):A31-A31
Introduction : Thermal injury to the female breast is one of the most challenging aspects of aesthetic burn surgery today. As the ability to provide coverage for large body surface injuries has progressed greatly in recent years; attention can now be directed towards achieving aesthetically pleasing results. Breast reconstruction in the burn patient can be accomplished in several ways. In planning the reconstruction, one must account for gender, age, and stage of breast development at the time of injury. The following is the treatment protocol utilized at our institution. After determining the level of injury the injured area is cleansed and treated with topical anti‐microbial agents such as Silvadene. If the decision is made to excise and graft the injured area one of two algorithms is followed. The first choice involves excising the burn and placing a split thickness skin graft to the area involved. This is done by placing a sheet graft and using aerosolized fibrin sealant to affix it to the wound bed. If the burn involves deeper elements of tissue then a second approach is taken which includes excision of the burn down to the level of fascia with preservation of the breast mounds and the nipple areola complex (NAR). The (NAR) is spared excision and allowed to heal. Reconstruction of the (NAR) can be deferred for a secondary procedure depending upon the response to primary healing. A split thickness skin graft is then applied to the area of injury. Again a sheet graft is preferred and fibrin sealant is utilized to improve graft fixation and contour. We attribute our excellent results to the sheet grafts and fibrin sealant used. It should be noted that the increased vascularity of the breast fat when compared to fat located elsewhere in the body allows the grafts to adhere and survive on this generally difficult to graft surface. Methods : We identified five female patients at our institution over the last 18 months with thermal injuries to the breasts. Each patient was placed into one of the two treatment algorithms. Results : The five patients had excellent outcomes. Breast mounds and symmetry were preserved. Further development of the breast was allowed in each patient. One patient even underwent a breast augmentation after surviving a 50% TBSA injury. Proper use of fibrin sealant and sheet grafts account for the excellent results seen at this institution. Conclusion : Following careful evaluation of the burned female breast cosmetically and functionally acceptable results can be attained when following our institution’s protocol for breast reconstruction in the female burn victim. 相似文献
66.
Janet Simpson M PhD MCS AFBPsS 《Physiotherapy》1998,84(10):469-471
67.
S A Rosenberg M T Lotze L M Muul S Leitman A E Chang J T Vetto C A Seipp C Simpson 《Surgery》1986,100(2):262-272
A new approach to cancer therapy has been developed based on the adoptive transfer of autologous lymphokine-activated killer (LAK) cells and recombinant interleukin-2 (IL-2). Forty-one patients with advanced cancer who have failed all standard treatments were treated in this experimental protocol. Fourteen patients experienced an objective regression of cancer, including one patient with metastatic melanoma who underwent a complete regression. Objective responses were seen in patients with colorectal cancer, renal cell cancer, melanoma, and lung adenocarcinoma. The sites of tumor regression included subcutaneous tissue, lung, and liver. The major side effect of therapy resulted from the administration of high-dose IL-2 and was manifested primarily as fluid retention, resulting in a generalized capillary permeability leak syndrome. This approach to adoptive immunotherapy represents a promising approach to the therapy of patients with metastatic cancer. Attempts to increase the potency and decrease the toxicity of therapy and extend this treatment to patients with smaller tumor burdens are in progress. 相似文献
68.
W G Simpson M W Vernon B E Maley M E Rush 《Gynecologic and obstetric investigation》1987,24(4):232-240
The relative roles of the cyclic nucleotide messengers cAMP and cGMP in the suppression of follicle-stimulating hormone (FSH) secretion in response to inhibin (IBN) were assessed employing rat gonadotropes in monolayer culture. While exposure of cells to gonadotropin-releasing hormone (GnRH) induced a significant increase in the amounts of both FSH and luteinizing hormone (LH) released into the culture medium, these responses were dampened by the administration of IBN (in porcine follicular fluid). Addition of cGMP to the system failed to restore FSH release, while cAMP restored basal FSH release. Modulation of nucleotide metabolism with theophylline, sodium nitroprusside, and a protein kinase inhibitor failed to overcome the IBN-induced suppression of FSH release. The cellular content of calmodulin increased in response to GnRH, a response antagonized by IBN. Cellular levels of cGMP were also increased by GnRH, but this response was unaltered by IBN. The administered drugs all failed to reverse these effects of IBN. These data indicate that the IBN-induced suppression of FSH release is not dependent upon the cyclic nucleotides cAMP and/or cGMP. However, a role in the maintenance of basal FSH synthesis and release for cAMP is indicated. 相似文献
69.
The 16-kDa α-crystallin (Acr) protein of Mycobacterium tuberculosis is required for growth in macrophages
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70.
Molecular epidemiology of nosocomial, multiply aminoglycoside resistant Enterococcus faecalis 总被引:4,自引:0,他引:4
J J Weems J H Lowrance L M Baddour W A Simpson 《The Journal of antimicrobial chemotherapy》1989,24(2):121-130
The prevalence of high-level aminoglycoside resistance among Enterococcus faecalis at the Memphis VA Medical Center was 23.6% (59 of 250 isolates) from October to December 1986. Hybridization to a probe cloned from Ent. faecalis pIP1800 for 6' acetyltransferase-2" phosphotransferase (AAC6'-APH2") was observed in 55 (93.2%) of the resistant isolates and was associated with gentamicin resistance. Hybridization to a probe cloned from Ent. faecalis pJH1 for 3', 5" phosphotransferase type III (APH3', 5" III) was observed in 28 (47.4%) and was associated with streptomycin resistance. Twenty-five of the 32 isolates which were resistant to both gentamicin and streptomycin hybridized to both probes. Cell mating in conjunction with hybridization indicated that the AAC6'-APH2" gene is transferred separately from that for APH3', 5" (III), and the streptomycin resistant gene is cotransferred with the latter. The gentamicin-streptomycin resistant isolates therefore contain genes from two Ent. faecalis plasmids, and resistance to these two antibiotics appears to transfer separately. The genetic homogeneity of these isolates suggests nosocomial transmission of enterococci. 相似文献