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1.
The rate of change of the mean of a quantitative character is evaluated exactly and also under the hypothesis of linear biparental regression. Generations are discrete and nonoverlapping; the monoecious population mates at random. The genotypic and environmental contributions to the character are additive and stochastically independent. The character is influenced by arbitrarily many multiallelic loci and has constant genotypic values; dominance, epistasis, and the linkage map are also arbitrary. The population is initially in linkage equilibrium, and there is no position effect. If the biparental regression is linear, then the regression coefficient is simply Vgam/V, and hence the single-generation change in the mean is deltaZ = (Vgam/V)S, where Vgam and V denote the gametic and total variances in the character and S designates the selection differential. The corresponding exact result is DeltaZ = (C/W) + (B/W2), where C, W and B represent the gametic covariance of the character and fitness, the mean fitness, and a correction term, respectively. If selection is weak, then DeltaZ approximately C/W. Furthermore, deltaZ = C/W if either there is no environmental contribution and the gametic effects are additive or the character is fitness itself. In the latter case, C is the gametic variance in fitness. Thus, even in linkage equilibrium, weakness of selection generally does not suffice to validate the linear-regression result. This conclusion holds even for additive loci.  相似文献   

2.
In the paper a survey on new results in the pharmacokinetics of ethanol is given. Resorption follows the rules of diffusion and is influenced by a lot of factors, this results in a high interindividual variation. Distribution is influenced by a first-pass-effect and the tissue contents of water. Metabolism is performed by alcohol dehydrogenase and microsomal ethanol oxidizing system. The kinetics of ADH is undependent on concentration, the MEOS is inducible. Results of acute and chronic ethanol treatment are discussed, clinical consequences are reviewed.  相似文献   

3.
新生血管是指从已有毛细血管发展形成新血管,该过程受血管生成因子和血管抑制因子双重调控,是一个动态平衡的过程。新生血管是多种疾病的病理性改变,包括肿瘤、早产儿视网膜病变和糖尿病视网膜病变等,是严重的致残性病变。建立新生血管动物模型是研究这些疾病发病机制的重要前提,本文主要对主动脉环血管生成模型、基质胶栓动物模型、氧诱导视网膜病变模型、激光诱导脉络膜新生血管动物模型4种建模方法进行了综述。  相似文献   

4.
Position of the arm has a definite and uniform effect on blood pressure readings. The systolic pressure is lowest when the arm is hyperabducted, that is, when it is made to lie along the long axis of the body. The systolic pressure becomes higher as the arm is adducted and brought toward the side of the body in the horizontal plane. A neutral position of the arm, 45 to 90 degrees from the side of the body, is probably the optimum position for the estimation of blood pressure. Other positions may cause a marked discrepancy in blood pressure readings.  相似文献   

5.
Treatment of the pruritus of cholestasis   总被引:2,自引:0,他引:2  
Opinion statement The etiology of the pruritus of cholestasis is unknown. It is inferred that the pruritogen( s) is produced in the liver, excreted in bile, and as a result of cholestasis it accumulates in plasma. It may follow, logically, that the removal of the substance(s) that mediate pruritus leads to its resolution. The problem with this approach, however, is that the substance(s) is unknown; thus, it is not possible to reduce its serum levels specifically. Oral cholestyramine, a resin that is not absorbed, is associated with increased fecal excretion of certain substances, including cholesterol and bile acids. Many patients respond to treatment with cholestyramine with a relief of pruritus, which unfortunately may be temporary, but is well tolerated in general and it seems reasonable to prescribe it as an initial therapy. When pruritus is not relieved by resins, the use of opiate antagonists (eg, naloxone and naltrexone) is supported by data from controlled clinical trials. Butorphanol is an agonist at the kappa opioid receptor and an antagonist at the mu opioid receptor with minimal or absent abuse potential. The use of butorphanol spray in selective patients may be a therapeutic alternative. In uncontrolled observations dronabinol, an agonist at the cannabinoid B1 receptor, and sertraline, a serotonin reuptake inhibitor, have been reported to be associated with the relief of pruritus. The cannabinoidergic and serotoninergic systems participate in the mediation of nociception; therefore, there appears to be a rationale for the use of these drugs to treat pruritus. Data from controlled clinical trials on the use of dronabinol and sertraline, however, are not available at present.  相似文献   

6.
Physiology of the Regulation of Platelet Production   总被引:7,自引:0,他引:7  
Platelet production is stimulated by removal or destruction of platelets and is inhibited by hypertransfusion with viable platelets. It is not influenced by factors regulating red cell production, even in the absence of the spleen. Nephrectomy does not impair the response to platelet depletion. It is concluded that the regulation of platelet production is by a system entirely independent of that governing erythropoiesis.  相似文献   

7.
Staging of cancer of the pancreas is relatively reliable when based on pathological material obtained from operative specimens or at autopsy. At operation, the assessment of disease stage, and therefore of operability, is more difficulty-particularly in relation to the extent of lymph node involvement and liver metastases. Preoperative staging, which, clinically, is the most essential, is difficult and unsatisfactory at the present time.  相似文献   

8.
This paper deals with some introductory topics of signal processing and decision making in cardiology. In both instances the matter is referred to general schemes well suited to host different applications. Signal processing is divided in some phases: acquisition, storing, analysis and each of them is described with applications to specific signals. In a similar manner the methods for decision making have been simplified to a scheme including a "knowledge base" and an "inference method". The scheme is used to classify various implementations. Bayes analysis and expert systems have been introduced with some details.  相似文献   

9.
Sphincter of Oddi dyskinesia (SOD) is a functional disorder of the papilla region that can lead to clinical symptoms and functional obstruction of biliary and pancreatic outflow. Based on the severity of the clinical symptoms, the disorder is classified as one of three types (biliary or pancreatic type I-III). Diagnosis of SOD is hampered by the relative risk of endoscopic sphincter manometry to cause pancreatitis. Manometrically, SOD is characterized by increased pressure in the biliary or pancreatic sphincter segment and can be treated with endoscopic papillotomy. This review is an attempt to balance the arguments for invasive diagnosis with a pragmatic clinical approach in which papillotomy is performed if clinical suspicion and patient presentation support a dysfunction of the papilla. For patients with biliary or pancreatic type I, endoscopic papillotomy is the treatment of choice. In biliary type II, SO manometry may be helpful for clinical decision making; however, the ratio of risks to benefits is difficult to assess based on the present data. In type III SOD, patient selection and the low predictive value of manometry for treatment success raise questions about the clinical usefulness of SO manometry.  相似文献   

10.
Intrahepatic cholestasis of pregnancy (ICP) is the most common liver disease during pregnancy, characterized by otherwise unexplained pruritus in late second and third trimester of pregnancy and elevated bile acids and/or transaminases. ICP is associated with an increased risk of adverse perinatal outcomes for the fetus and the later development of hepatobiliary disease for the mother. Bile acids should be monitored throughout pregnancy since fetal risk is increased at serum bile acids >40 µmol/l. Management of ICP consists of treatment with ursodeoxycholic acid, which reduces pruritus. Early elective delivery is common practice but should be performed on an individualized basis as long as strong evidence supporting this practice is lacking. Mothers should be followed-up for normalization of liver function tests 6–12 weeks after delivery. Future research in large-scale studies is needed to address the impact of ursodeoxycholic acid and early elective delivery on fetal outcome.  相似文献   

11.
Bronchiolo-alveolar carcinoma is a rare primary lung tumour, which is difficult to diagnose by cytological techniques. This peripheral tumour, which develops on pre-existing alveolar walls, is not visible on bronchial endoscopy and brushing is often negative. The cellular material derived from aspiration or expectoration is characterised by numerous papillae, without any cytonuclear criteria of malignancy. The differential diagnosis is very difficult with reactive papillary hyperplasia and various forms of chronic bronchial inflammation. Transparietal aspiration lung biopsy facilitates the diagnosis of glandular carcinoma: the material examined corresponds to pathological tissue, as the biopsy is performed under image intensifier control. An inflammatory lesion is excluded by the rich cellularity and by the presence of architectural features of malignancy: cohesive and three-dimensional clumps of papillary tumour cells. The early cytological diagnosis of bronchiolo-alveolar and primary bronchiolar carcinomas of the lung by transparietal aspiration biopsy can allow the surgical cure of certain localised forms.  相似文献   

12.
Demographic situation in male population of Russia is analyzed in this review. The role of diseases of cardiovascular system and urogenital diseases including sexual disorders and androgen deficiency state in lowering of quality and duration of life of reproductive age men is shown. Modern outlook on metabolic syndrome, erectile dysfunction and androgen deficient state is presented. Meta-analysis of clinical studies of systemic effects of hormonal replacement therapy with the use of testosterone is conducted and problems of safety of its long term use are studied. An integrated scheme of diagnosis and treatment of erectile dysfunction, androgen deficient state and cardiovascular diseases is presented in this paper.  相似文献   

13.
Prophylactic treatment from ages 2 to 18 years could prevent the development of hemophilic arthropathy if the concentration of the patient's deficient factor is kept from falling below 1% of normal. Early treatment is of paramount importance because the immature skeleton is very sensitive to the complications of hemophilia. Major hemarthrosis and chronic hemophilic synovitis should be treated aggressively to prevent hemophilic arthropathy. When advanced hemophilic arthropathy is present with severe disability, the aim should be to restore function while minimizing the risk to the patient. Joint debridement is an effective method to achieve this goal, especially around the elbow or ankle, and can be considered an alternative to knee replacement in the younger age groups. Proximal tibial valgus osteotomy is a reliable treatment method for painful genu varum of the mobile hemophilic knee. Supramalleolar tibial varus osteotomy is an attractive alternative to the more commonly used surgical option of arthrodesis. Finally, joint replacement can usually be relied on to restore both mobility and function in a diseased joint. The potential benefits of joint replacement must always be weighed against the long-term sequelae, however, especially loosening and consequent revision surgery.  相似文献   

14.
Shoulder dysfunction is unusual in osteoarthritis and usually responds to conservative treatment. The primary indication for surgery is pain unresponsive to medical management. The procedure of choice for degenerative changes in the glenohumeral joint is hemiarthroplasty or total shoulder replacement depending on the condition of the glenoid. Shoulder fusion is rarely necessary for osteoarthritis and is recommended for chronic infection, flail shoulder, and failed total shoulder replacement not amenable to revision. Joint resection is reserved for infected joints with massive bone loss. The results of shoulder arthroplasty are good to excellent in 86 to 94 per cent of all patients. The results of shoulder arthrodesis are less predictable, but are usually satisfactory in approximately 75 per cent of patients with 10-year follow-up. The treatment of AC and SC joint arthritis is conservative with rest, local heat, and medication. Pain unresponsive to this regimen is an indication for resection of the joint. Good results with this procedure directly correlate with pain relief on injection of the joint with local anesthetic.  相似文献   

15.
Conclusions Local treatment of carcinomain situ of the rectum is the procedure of choice. It is also preferable when there is a focal malignant change in a polyp with a pedicle that is not invaded by the cancer, and when a sessile carcinoma of low grade is less than 2 cm. in diameter. These indications may be extended in some cases when the general condition of the patient precludes a radical surgical procedure, when the patient, because of a poor mental condition, would not be able to manage the colostomy himself, and when a colostomy is refused. When a carcinoma of the rectum is inoperable, or when there is distant metastasis, local treatment may provide gratifying palliation. Read at the Canberra meeting of the Royal Australasian College of Surgeons. Canberra, Australia, November 28, 1964.  相似文献   

16.
Summary and Conclusions Knowledge of epidermoid carcinoma of the anal canal and perianal area is incomplete. The rarity of the disease, differences of opinion and variability of criteria used in investigations cause confusion. Investigation of the nature of epidermoid carcinoma and the efficacy of various methods of therapy is not complete unless pertinent surgical anatomy is considered. The results after local excisionvs. those after abdominoperineal resection in several large reported series are compared. Eight patients treated by local excision are reported. A practical outline for investigation is recommended. Early diagnosis is the most important factor for success of any method of therapy. Exfoliative cytology as a technic for early diagnosis was investigated in six patients and, owing to the small sample, the need for further study is suggested. Wide local excision of some epidermoid carcinomas of the anal canal and perianal skin is safe and adequate therapy. Opinions differ regarding the selection of patients for this method of treatment. Read at the meeting of the Northwest Proctologic Society, Parksville, Vancouver Island, British Columbia, August 25 to 28, 1968.  相似文献   

17.
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   

18.
肺小血管炎(SVVL)是原发性小血管炎累及肺脏血管的一组疾患.因本病与抗中性粒细胞胞浆抗体(ANCA)密切相关,故称为抗中性粒细胞胞浆抗体相关性小血管炎(AAVS).主要包括:韦格纳肉芽肿病(WG)、显微镜下多血管炎(MPA)、变应性肉芽肿性血管炎(CSS)[1],常可累及多个系统.肺是原发性小血管炎累及频率最高的脏器之一,据报道肺脏受累占75%,仅次于肾脏,且是造成死亡的主要原因.其临床表现复杂多变,缺乏特异性,常常被误诊为其它疾病,延误治疗.而经积极治疗,其生存率明显上升.因此有必要提高对SVVL的认识.  相似文献   

19.
Blood from the adrenal gland can flow in two directions--into the caudal vena cava and by anastomoses into the portal vein. A method of multiple blood procuring from these vessels in dogs for the purpose of studying the adrenal gland function is suggested. Polyethylene catheters, 0.9 mm in diameter and 35--40 mm in length glued to capron plates, mandrins, Gordeev's needles and blood-drawing needles are necessary. Transperitoneal surgical approach to the caudal and mesenteric veins is to be provided. Purse-string suture is applied on the wall of the mesenteric vein. The catheter is washed with heparin, the mandrin is introduced into it and it is inserted into the Gordeev's needle. A puncture is made in the centre of the purse-string suture with this needle, which is introduced into the vein together with the catheter. Gordeev's needle is withdrawn and the catheter is pushed through to the portal vein. The purse-string suture is tightened, and the capron plate is fixed in the wall of the vein. The mandrin is recovered from the catheter, heparin is administered into its canal, polyethylene plug is inserted and withdrawn through the abdominal wall outside with the aid of the blood-drawing needle. The catheter is introduced into the caudal vena cava in the same way. Blood samples can be obtained on the 14th postoperative day.  相似文献   

20.
<正>从1855年Thomas Addison 首次报道肾上腺皮质功能减退症(adrenal insufficiency,AI),到1949年糖皮质激素(glucocorticoid,GC)替代治疗运用于临床,近100多年AI的诊治取得很多重大成果。肾上腺皮质主要分泌盐皮质激素、GC和性激素。AI是指由于各种原因导致基础或者应激状态下肾上腺皮质激素分泌减少所致的疾病,AI按病因分为原发性肾上腺皮质功能减退症(primary adrenal i  相似文献   

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