共查询到20条相似文献,搜索用时 187 毫秒
1.
The coagulation time is a measurement of the intrinsic power of the blood toconvert fibrinogen to fibrin. It is an empirical test no matter how performed, andtherefore in order to be reliable requires that the test be done on venous blood understrictly controlled conditions. A recommended procedure is outlined in detail.The coagulation time is prolonged in hemophilia, hypoprothrombinemia,afibrinogenemia and heparinemia. In hemophilia, the coagulation time theoretically is a measure of the severity of the disease but practically is of limited valuesince the coagulation time may be within normal limits in some patients; the prothrombin consumed in the coagulation of hemophilic blood is therefore a betterguide for diagnosis. The coagulation time in hypoprothrombinemia is relativelylittle prolonged until a drastic reduction occurs. The test is therefore of no value forestablishing a hemorrhagic condition in hypoprothrombinemia. In afibrinogenemiathe blood is incoagulable. A small amount of fibrinogen restores the coagulationtime to normal.The presence of heparin increases the coagulation time. The test is therefore useful in controlling the therapeutic action of this drug.The senior author, in making a survey of the literature on hemorrhagic diseasesin preparation of his monograph, was impressed by the significant and diverse contributions which Dr. George R. Minot made to this field of medicine. We feelhonored to contribute this study to the collection of papers offered as a fittingtribute to Dr. Minot, who has so successfully and productively combined scienceand clinical medicine. 相似文献
2.
Jonathan B. Wittenberg Beatrice A. Wittenberg J. Peisach W. E. Blumberg 《Proceedings of the National Academy of Sciences of the United States of America》1970,67(4):1846-1853
The structure of the oxygenated heme group of oxyhemoglobin may be formulated as [Hb(Heme d(1/2) (5)).OO(-)]. The heme iron atom is formally ferric, and the ligand is bound superoxide anion. When deoxyhemoglobin combines reversibly with oxygen a partial transfer of an electron occurs from the ferrous iron atom to the oxygen molecule. By surrendering its electron the iron atom has become ferric; in accepting an electron the ligated oxygen molecule has become a new species, the bound superoxide anion (.OO(-)).The configuration of the heme iron atom is deduced from comparison of the optical spectrum in the visible region of oxyhemoglobin with that of alkaline ferric hemoglobin whose configuration is established by electron paramagnetic resonance spectroscopy. The configuration of both species is low spin ferric heme iron (Heme d(1/2) (5)). The configuration of the ligated oxygen molecule of oxyhemoglobin is not accessible to study by magnetic or optical probes. However it may be known by analogy with the configuration of the ligated oxygen molecule of reversibly oxygenated cobalt complexes whose structure has been proved by both electron paramagnetic resonance and x-ray diffraction analysis. It is bound superoxide anion (.OO(-)). Other physical studies bearing on the structure of the oxygenated heme group are discussed. Reasons are given for believing that the proposed formulation of the oxyhemoglobin structure is consistent with the known stability of oxyhemoglobin. 相似文献
3.
O P Zelia V D Zavo?kin M N Sergeeva 《Meditsinskaia parazitologiia i parazitarnye bolezni》1990,(4):22-25
Opisthorchiasis morbidity is reviewed in the area of the Vasyugan River, an Ob tributary. Intermediate hosts have been found in 3 settlements situated at various distances from the ostium. The infestation of intermediate and additional hosts with Opisthorchis larvae is investigated. The above data and the results of previous population surveys (establishing infestation and contamination) served the basis for elucidating the nature of helminth circulation on the territory along the Vasyugan River. The role of infected fish migration is discussed as a source of human infection in areas where helminth circulation is altogether absent or is at an extremely low level. 相似文献
4.
M.S. Hidehiro Hosaka Ph.D. David Cohen Ph.D. B. Neil Cuffin Ph.D. B. Milan Horacek 《Journal of electrocardiology》1976,9(4):418-425
The magnetic field produced by a current dipole is made up of two parts: the field from the dipole element, and from the current generated by the dipole in the volume conductor. It was previously shown for the semi-infinite volume conductor, infinite slab, and the sphere that the volume-current contribution is zero to the component of magnetic field which is normal to the boundary. The volume conductor in the form of the human torso is here investigated by computer simulation. Three different heart-torso models are used. The contribution to the normal field component (Bn) by the volume current (via the boundaries) and by the heart dipoles are computed. For comparison, the boundary contribution to the surface potential (V) is also computed. For Bn the three models yield a ratio of boundary to dipole contribution in the same range, with 0.28 as the average. Simple subtractions can make this ratio negligible. For V the equivalent ratio is somewhat greater. The arrow map, developed previously to display Bn over special surfaces, is shown to be valid for the human torso, for visually estimating the heart dipoles. 相似文献
5.
Pumping blood in one direction is the main function of the heart, which is equipped with valves that ensure unidirectional flow. During early embryonic life, blood circulates in one direction through the primitive circulatory system, in spite of the complete lack of valves. A mathematical model has been developed in order to describe the coordinated fashion of the blood circulation in the circulatory system of the embryo. The blood flow is considered as one-dimensional, employing the momentum and continuity equations. Also a constitutive state equation is used relating pressure and circuit lumen. The one-dimensional model is analysed numerically and solved with a dispersion-relation-preserving (DRP) scheme of finite difference, which is of fourth order accurate. The size of the mean flow depends on the embryonic heart rate and the contraction grade of primordial heart tube. Three functions in time and space are calculated, the cross section area of the lumen, the building up internal pressure and the velocity of the blood inside the circuit. The pumping activity of the embryo circulatory system is shown by presentation of the mean flow-rate of the blood as a function of embryonic heart rate for several contraction grades of primordial heart tube. 相似文献
6.
目的本文旨在了解医务人员现代结控知识掌握的现状及培训效果?方法于培训前后进行问卷调查,内容包括:病例发现?结核病诊断及化疗?结果培训前疫情报告和转诊,回答正确者占75.2%?71.7%;对临床表现?查痰和诊断依据,回答正确者占83.5%?42.5%?40.8%;抗痨药物?用药方法?化疗原则?短化方案?短化疗程?治愈标准六项,回答正确者占58%?14.4%?20.8%?9.2%?17%?24.3%?培训后再次调查发现,90%以上医务人员对现代结控基本知识已掌握?结论各级医务人员现代结控知识是很贫乏的,因此,对其进行系统培训是极为必要的,此项工作省时?省力?投入少,可收到事半功倍的效果。 相似文献
7.
刘宇宏 《中华现代内科学杂志》2005,2(10):880-882
目的探讨我国临床中抗生素使用与致病菌耐药的因果关系。方法综合分析困内外抗生素使用情况及耐药菌发展趋势。结果由于诸多因素所导致的抗生素滥用现象非常普遍,抗生素药物的总体使用率偏高,大约70%~80%,耐药菌种类日趋增多。结论有必要对抗生素的使用进行规范,围绕着抗生素的合理使用制订出“抗生素应用政策”,并采取一定的措施和干预手段,使这一政策有效的贯彻和实施。 相似文献
8.
Obesity: the science behind the management 总被引:1,自引:0,他引:1
Steinbeck K 《Internal medicine journal》2002,32(5-6):237-241
The prevalence of obesity is increasing in Western and Westernizing countries. The changing environment plays a major role in this increase, particularly the reduction in physical activity. There is also a strong genetic contribution to the development of obesity, although single-gene defect obesity is rare. Neither the environment nor genes is simple to modify. Obesity is an energy-balance disorder, and the human body has evolved to resist any loss of body fat. This biological drive to maintain weight is coordinated through central pathways, with the involvement of many neuropeptides. Thus, dietary restriction will induce changes designed to counter weight loss, including a fall in resting metabolic rate. The management of obesity demands reasonable goals, which focus on metabolic, rather than cosmetic, improvement. As obesity is a complex condition, multiple therapeutic strategies are required. Dietary modification, an increase in physical activity, a reduction in sedentary activity and behaviour modification all form the basis of obesity therapy. Drug therapy options at present are limited and may have a stronger role in weight maintenance. Currently, surgical management of obesity has the best long-term outcomes. Long-term maintenance of weight loss is achieved by few individuals. Those individuals who are successful are able to maintain long-term restrictive eating habits and high levels of physical activity. 相似文献
9.
A concept of the anatomy of the anal sphincter mechanism and the physiology of defecation 总被引:4,自引:0,他引:4
Ahmed Shafik M.D. 《Diseases of the colon and rectum》1987,30(12):970-982
A review of the new concepts of the anatomy of the anal sphincter mechanism and the physiology of defecation is presented.
The external sphincter is a triple-loop system; each loop can function as a separate sphincter through voluntary inhibition
action and mechanical compression. Stress defecation resulting from internal sphincter damage is described. A new technique
for repair of rectal incontinence is presented, which depends on inducing continence not only by mechanical compression, but
also by voluntary inhibition. The mechanism of defecation and rectal continence is described and four types of incontinence
presented. Also, the mechanism of both the levator dysfunction syndrome and prolapse is demonstrated and a technique of repair
is presented. The study defines two types of rectal anomalies: suprahiatal and infrahiatal. The role of the embryonic anorectal
sinus, anorectal band, and epithelial debris in the genesis of perirectal suppuration, chronic anal fissure, pruritus ani,
and hemorrhoids is described. The communicating veins, identified between the hemorrhoidal and vesical plexuses, offer an
explanation for the vague pathologic aspects of recurrent bacteriuria, urethral discharge, cervicitis, and vaginitis, and
provide a proper line for their treatment. They also serve to perform a new radiographic technique—anal cystography—and to
administer drugs, including chemotherapeutics, in the treatment of pelvic malignancies. 相似文献
10.
Finnegan TP 《Zeitschrift für Gerontologie und Geriatrie》2001,34(3):170-175
The Australian Health care system is a mix of public and private provision. The Federal Government funds medical care and the pharmaceutical benefit scheme while the State Governments are responsible for funding the public hospitals. Geriatric Medical care is provided in the public hospital system. The Australian DRG system has evolved to more adequately explain illness severity by a greater use of the complications and comorbidities. The structure of the Sub-Acute and Non-Acute Patient (SNAP) classification is outlined. While it is anecdotally said that the introduction of DRG-based funding is detrimental to the elderly, the published evidence does not support this. The potential benefits of a casemix system are discussed. 相似文献
11.
12.
A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation 总被引:1,自引:0,他引:1
Dr. Ahmed Shafik M.D. 《Diseases of the colon and rectum》1980,23(1):37-43
The role of the external and internal anal sphincters in the mechanism of anal continence is presented. The external sphincter
induces continence by 1) preventing internal sphincter relaxation, what I have called the “voluntary inhibition action,” and
2) mechanical compression of the rectal neck and anal canal proper. The mechanism of both actions is described. The internal
sphincter plays a significant role not only in involuntary, but also in voluntary, continence. The importance of this role
in the correction of anal incontinence is clarified. “Stress defecation,” a condition which follows internal sphincter damage,
is discussed. A “single loop continence” theory is presented, based on the fact that each of the three loops of the external
sphincter has its own innervation, attachment, and direction of muscle bundles; each loop thus acts as a separate sphincter.
The clinical application of this theory is presented. 相似文献
13.
Barenblatt GI Chorin AJ Kast A 《Proceedings of the National Academy of Sciences of the United States of America》1997,94(24):12762-12764
The classical problem of thermal explosion is modified so that the chemically active gas is not at rest but is flowing in a long cylindrical pipe. Up to a certain section the heat-conducting walls of the pipe are held at low temperature so that the reaction rate is small and there is no heat release; at that section the ambient temperature is increased and an exothermic reaction begins. The question is whether a slow reaction regime will be established or a thermal explosion will occur. The mathematical formulation of the problem is presented. It is shown that when the pipe radius is larger than a critical value, the solution of the new problem exists only up to a certain distance along the axis. The critical radius is determined by conditions in a problem with a uniform axial temperature. The loss of existence is interpreted as a thermal explosion; the critical distance is the safe reactor's length. Both laminar and developed turbulent flow regimes are considered. In a computational experiment the loss of the existence appears as a divergence of a numerical procedure; numerical calculations reveal asymptotic scaling laws with simple powers for the critical distance. 相似文献
14.
The influence of a long-term T4 injection on the gonadal and adrenal androgenic function as well as on the hypophyseal gonadotropic activity was studied in experiments on adult male rabbits, using histological and hormonal methods. It was shown that in rabbits with experimental moderate thyroxin toxicosis the testicular testosterone secretion is inhibited, whereas the adrenal testosterone secretion is compensatory enhanced. The level of hypophyseal gonadotropins tends to rise. The prostatic weight is lowered, but the glandular epithelial cells retain the ability of secreting. The thyroid hormone role in the hypophyseal-adrenal-gonadal function in health and hypothyrosis is discussed. 相似文献
15.
16.
The secretion covering the surface of the bronchioles can be demonstrated with the scanning electron microscope if fixative is introduced into the pulmonary artery or directly into the lung rather than through the trachea. Buffered glutaraldehyde, ethanol, or an ethanol-ether mixture can be used as a fixative. With this method of preparation the surface secretion appears as a smooth coating covering the cilia and cells. The secretion is insoluble in ethanol ether or chloroform methanol, suggesting that there is little lipid contained in it. Reasons are cited for believing that the major component of the secretion is a protein that arises from the Clara cell. 相似文献
17.
Gueirard P Tavares J Thiberge S Bernex F Ishino T Milon G Franke-Fayard B Janse CJ Ménard R Amino R 《Proceedings of the National Academy of Sciences of the United States of America》2010,107(43):18640-18645
The first step of Plasmodium development in vertebrates is the transformation of the sporozoite, the parasite stage injected by the mosquito in the skin, into merozoites, the stage that invades erythrocytes and initiates the disease. The current view is that, in mammals, this stage conversion occurs only inside hepatocytes. Here, we document the transformation of sporozoites of rodent-infecting Plasmodium into merozoites in the skin of mice. After mosquito bite, ~50% of the parasites remain in the skin, and at 24 h ~10% are developing in the epidermis and the dermis, as well as in the immunoprivileged hair follicles where they can survive for weeks. The parasite developmental pathway in skin cells, although frequently abortive, leads to the generation of merozoites that are infective to erythrocytes and are released via merosomes, as typically observed in the liver. Therefore, during malaria in rodents, the skin is not just the route to the liver but is also the final destination for many inoculated parasites, where they can differentiate into merozoites and possibly persist. 相似文献
18.
A. Wennevold 《Catheterization and cardiovascular interventions》1980,6(3):325-329
A technique is described by which a catheter is advanced from the left atrium to the left ventricle during a right heart catheterization via the leg. A loop in the catheter is created by the clockwise twisting of the catheter while it is gently pushed against the posterior left wall of the left atrium. The catheter is then pulled back and is twisted counter-clockwise. The catheter has to be soft, and biplane fluroscopy is required. During a 16-month period 162 consecutive infants and children had heart catheterization performed, during which a pediatric NIH catheter was passed to the left atrium. The loop-technique was attempted in 95 patients and was successful in 66 patients. One or two attempts were usually sufficient. No complications were encountered apart from two brief episodes of bradycardia. The technique is easy to perform with a reasonable success rate. It seems most useful in infants in whom 5F catheters are used. 相似文献
19.
The epithelium lining spermatogenic cysts in the testis of the teleost Oryzias latipes was investigated with the electron microscope. The cyst epithelium (CE) is simple squamous until the onset of the transformation of spermatids into spermatozoa, at which time the CE become columnar. The squamous CE cell is relatively poor in organelles, but the columnar CE cell contains numerous glycogen granules and smooth endoplasmic reticulum, and shows evidence of much phagocytosis. A limiting membrane in the subjacent connective tissue is described.The cytological features and histological relationships of the CE are compared with those of the Sertoli cell of the mammalian seminiferous epithelium. The CE cell is believed to be the homolog of the Sertoli cell in testes of teleosts. 相似文献
20.
V A Krasnov 《Problemy tuberkuleza》1991,(3):13-16
Analysis of the epidemiological parameters related to tuberculosis in Western Siberia for the last 30 years is given. Tuberculosis still manifests itself as a social disease. The last decade is marked by a slowing down of morbidity reduction. A continuing decrease of registered morbidity is associated with undetected tuberculosis cases owing to a 10-20% reduction of mass population screening. The problem of the interconnection of human and farm animal tuberculosis is still actual for Western Siberia. Morbidity rate among the farm workers in unfavourable regions amounts to 250 per 100,000. Successful tuberculosis control requires joint efforts of phthisiologists, veterinarians and organs of power. 相似文献