In a retrospective study of 217 patients, smoking habits were related to the late patency rates of arterial reconstructions performed for ischaemia of the legs. Patients who had stopped smoking or who smoked no more than 5 cigarettes per day after the operation had late patency rates of approximately 90 per cent for aortofemoral reconstructions and 80 per cent for femoropopliteal vein grafts. Patients who continued to smoke more than 5 cigarettes per day were approximately three times more likely to block an aortofemoral reconstruction and four times more likely to block a femoropopliteal vein graft. The results were similar for males and females, for various age groups, for claudicants and patients with severe ischaemia and for aortofemoral endarterectomy and Dacron grafts. The late patency rate was approximately inversely proportional to the number of cigarettes smoked per day after the operation. There was no such correlation with the number smoked per day before the operation.
Incomplete knowledge of pedigrees sometimes limits the methods of estimating quantitative genetic parameters (heritability, genetic correlation) in nature and may result in estimates that are inflated by nongenetic sources of variation. North American garter snakes and their allies provide a model system for investigating evolutionary quantitative genetics, but estimates of quantitative genetic parameters in these snakes are mostly based on offspring-dam regression and full-sib analysis, methods that fail to discriminate between maternal genetic, maternal environmental, and direct genetic effects on traits of interest. Using data from the garter snake Thamnophis sirtalis, we demonstrate that microsatellite DNA markers can be used to identify full-sib sireships within litters in species that produce large numbers of offspring and in which multiple paternity is common. This allows estimation of quantitative genetic parameters using a maternal half-sib analysis in which sires are nested within dams. Six microsatellite DNA loci were scored for four wild-caught dams and their 73 offspring and revealed two full-sib sireships within each litter. Maternal half-sib analyses of scalation and behavior suggest that heritability may be lower and maternal effects larger than was previously thought.Résumé : La connaissance incomplète des pedigrees impose parfois des limites aux méthodes d'estimation des paramè-tres génétiques quantitatifs (héritabilité, corrélation génétique) en nature et risque de donner lieu à des estimations qui sont gonflées par des sources non génétiques de variation. Les Couleuvres rayées nord-américaines et leurs alliés constituent un système modèle pour l'investigation de la génétique évolutive quantitative, mais les estimations des paramè-tres génétiques quantitatifs de ces couleuvres sont basés principalement sur des régressions mère-progéniture et sur l'analyse des vrais frères et soeurs, méthodes qui ne tiennent compte ni de la génétique maternelle, ni de l'environnement maternel, ni des effets génétiques directs sur les caractéristiques d'intérêt. À partir de données sur les couleuvres Thamnophis sirtalis, nous démontrons que les marqueurs d'ADN microsatelllites peuvent servir à identifier les paternités des vrais frères et soeurs dans les portées chez les espèces qui produisent une importante progéniture et qui comptent de nombreux cas de paternité multiple. Cette méthode permet d'estimer les paramètre génétiques quantitatifs au moyen d'une analyse des demi-frères (soeurs) maternels dans laquelle les différents pères ont été emboîtés dans chacune des mères. Six locus de microsatellites d'ADN ont été évalués chez quatre femelles capturées en nature et chez leurs 73 rejetons et ont mis en évidence deux cas de paternité complète dans chaque portée. Les analyses des demifrères (soeurs) maternels de la répartition des écailles et du comportement indiquent que l'héritabilité est peut être moins élevée que prévu et les effets maternels plus importants qu'on ne le croyait.[Traduit par la Rédaction] King e...
Over a 10-year period, 411 patients with atherosclerotic major artery disease causing severe ischaemia of the legs were treated by surgery. Their survival rate, assessed by the life table method, was 80 per cent at 1 year and 50 per cent at 5 years. Early and late survival rates were significantly worse in elderly patients, and in patients with extensive gangrene. Late survival rates were significantly worse in diabetics, and in patients with clinical myocardial ischaemia. Patients treated by arterial reconstruction showed a better survival rate than those treated by sympathectomy or amputation, though the latter groups contained more poor risk patients. Survival rates were not influenced by the technique of reconstruction.
Three cases of early aneurysmal degeneration of modified human umbilical vein (HUV) grafts in the femorodistal segment are described. One such graft is the first reported with multiple true aneurysms. The pathology and management of this complication is discussed.
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