共查询到20条相似文献,搜索用时 15 毫秒
1.
Journal of Ichthyology - An Erratum to this paper has been published: https://doi.org/10.1134/S0032945221440016 相似文献
2.
M. J. Brown 《BMJ (Clinical research ed.)》1997,314(7089):1258-1261
The abundance of drugs now available for treating hypertension, and evidence that small reductions in blood pressure reverse the associated risk of stroke have shifted clinical concerns away from hypertension. However, we do not understand the cause of hypertension in 95% of patients, fail to achieve a normal blood pressure in 50% of patients, and are unable fully to reverse the cardiac and vascular changes that predate the diagnosis and treatment of hypertension. Consequently, hypertension remains the commonest cause of strokes in Britain and of renal failure in the United States. Essential hypertension is a polygenic disease whose understanding can now be advanced through molecular genetic analyses. Several different syndromes are likely to be recognised; most will be due to interactions between genetic and environmental factors, but there are also likely to be further monogenic syndromes in families with multiple affected members. Recognition of these syndromes will permit accurate genetic prediction of prognosis and optimal treatment and perhaps lead to new and more powerful classes of antihypertensive treatment. 相似文献
3.
Age, growth, and reproductive biology of the blackbelly rosefish from the Carolinas, U.S.A. 总被引:1,自引:0,他引:1
Otoliths and gonads of blackbelly rosefish Helicolenus dactylopterus dactylopterus were collected from the commercial fishery off the Carolinas in 1994–1997. Opaque bands on transverse sections of otoliths were determined to be annuli by analysis of marginal increments. Opaque zone formation occurs between July and January. Ages ranged from 7 to 30 years. Blackbelly rosefish have intraovarian gestation. Fertilization is internal, as free spermatozoa were found primarily in resting ovaries from July through early December with peak occurrence in September through November. There was a delay of 1–3 months before fertilization, as oocyte development did not begin until December. Occurrence during January through April of early-celled embryos, the most advanced stage observed, and postovulatory follicles indicated that oocyte development was rapid. Egg development occurs in a clear gelatinous matrix secreted into the ovarian cavity. The reproductive mode is a zygoparous form of oviparity, intermediate between oviparity and viviparity. Population sex ratio departed markedly from 1: 1 for most length intervals. Males were more abundant at lengths >250 mm L T and the overall male: female ratio was 1 : 0·60. 相似文献
4.
S. Krishna 《BMJ (Clinical research ed.)》1997,315(7110):730-732
5.
Prostaglandins are part of the family of oxygenated metabolites of arachidonic acid known collectively as eicosanoids. While they are formed, act, and are inactivated locally and rarely circulate in plasma, they can affect blood flow in some tissues and so might contribute to the control of peripheral vascular resistance. Few studies have shown any derangement of total body prostaglandin synthesis or metabolism in hypertension, but increased renal synthesis of one prostanoid, thromboxane A2, has been noted in spontaneously hypertensive rats and some hypertensive humans. This potent vasoconstrictor may account for the increased renal vascular resistance and suppressed plasma renin activity seen in many patients with hypertension. Increased renal vascular resistance could increase the blood pressure directly as a component of total peripheral resistance or indirectly by increasing glomerular filtration fraction and tubular sodium reabsorption. Specific thromboxane synthesis inhibitors not only decrease renal thromboxane production but also increase renal vasodilator prostaglandin synthesis when prostaglandin synthesis is stimulated. This redirection of renal prostaglandin synthesis toward prostacyclin might be of benefit in correcting a fundamental renal defect in patients with hypertension. 相似文献
6.
7.
8.
Neoplastic diseases of the kidneys and urinary collecting system are relatively common, but when detected early, they have an excellent prognosis. Because gross or microscopic hematuria may be an early harbinger of genitourinary pathology, the primary care physician and internist play an integral role in diagnosing these diseases. A high index of suspicion together with a thorough history, physical examination, and appropriate diagnostic studies will enable the correct diagnosis and improved patient management in most cases. 相似文献
9.
10.
Rats hypophysectomized at 6 days of age continue to grow but at a subnormal rate. At 24 days, when maturation of the intestinal epithelium normally culminates, the intestine is disproportionately small. The crypts are shallow and the mitotic rate low. The villi are short, and they fail to achieve the broad, leaflike form found in controls. The absorptive cells acquire a deep subnuclear zone, and their surfaces apparently cease to carry on pinocytosis. Rough endoplasmic reticulum is however sparse, and the Golgi complexes are small and atypical in structure. Duodenal alkaline phosphatase remains at the low level characteristic of the neonatal intestine. Sucrase activity appears in the jejunum, and maltase activity increases slightly, but both activities are less than a third of those in intact animals at 24 days. If the pituitary is removed later than 6 days, enzyme activities are higher than after early ablation, but they remain deficient even when the operation is performed at 16 days. 相似文献
11.
S. J. Russell 《BMJ (Clinical research ed.)》1997,315(7118):1289-1292
12.
13.
J. Wilding 《BMJ (Clinical research ed.)》1997,315(7114):997-1000
14.
15.
Sex, cell death, and the genome of C. elegans. 总被引:3,自引:0,他引:3
16.
17.
18.
19.
20.
G W Hinsch 《Journal of morphology》1966,119(3):327-339
Tissues of White Leghorn embryos of stages 17–45 and chicks of one day, two days, and three weeks of age were frozen, sectioned in a cryostat and, where appropriate, were fixed in cold calcium formol. Acid phosphatase, non-specific esterase, adenosine triphosphatase, 5-nucleotidase, non-specific glycerophosphatase, nucleotidediphosphatase, and glucose-6-phosphatase were localized in these tissues. Ribonucleic acid, acid mucopolysaccharides, triglycerides, and neutral fats were localized in tissues fixed with FAA and embedded in paraffin. Positive acid phosphatase reactions were obtained in the epithelium of the trachea and esophagus at all stages of development. 5-nucleotidase was found in the muscularis mucosae of the esophagus at all stages. Non-specific esterase appeared with histodifferentiation of the esophageal epithelium. Ribonucleic acid was localized in the basal regions of the epithelium. Mucous glands of the esophagus are rich in ribonucleic acid and acid phosphatase at all stages of development. With histodifferentiation and the onset of secretion of sulfated acid mucopolysaccharides, the glands and their ducts become highly reactive for adenosine triphosphatase and nucleotide-diphosphatase, indicating a role of these enzymes in secretion. 相似文献