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Significant advances in open heart surgery during the last two decades were achieved in the field of the extracorporal circulation and the preservation of the myocardium. In the last few years, new therapeutical tools were introduced to treat patients with coronary artery disease. The transmyocardial laser revascularization (TMR) technique was introduced for clinical investigation 1990. Despite limited experience with this device in selected patients, some conclusions after a short follow-up period are available. Patients treated with TMR have significantly less anginal pain and need fewer hospitalisations. With PET follow-up studies, a better subendocardial perfusion at the expense of the subepicardial perfusion was demonstrated. On the other hand, there was no substantial increase found in terms of ejection fraction in treated patients. Minimally invasive procedures have also gained acceptance during the last few years, especially the minimally invasive coronary artery bypass procedures (MIDCAB). Introduced initially to treat solitary stenoses of the LAD without cardiopulmonary bypass, this procedure is actually often used in conjunction with PTCA for three-vessel disease in selected patients. Due to the different methods used and summarized under the term of MIDCAB, definite conclusions about the advantages of this method are difficult to formulate. There is a trend to reduced patency rates of the IMA bypasses in MIDCAB procedures compared to the conventional technique due to the difficulty with limited access.  相似文献   

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Mothers' preparatory instructions (comments, helpful advice, and suggestions) intended to assist their child in subsequently joining the play of an unknown pair of children were studied. What mothers said to their child while they actually joined in (contemporaneous instructions) was investigated, as well as their claims about the kind of feedback they would give the child after the play. Mothers of popular, rejected, and neglected children were compared. It was hypothesized that the instructions mothers gave would parallel the known group-entry behavior of these groups of children. Hypotheses were substantially supported for mothers of popular children, moderately supported for mothers of neglected children, and less supported for mothers of rejected children. The most consistent finding was that mothers of popular children were more likely to suggest a group-oriented entry strategy to their child. These results tend to support previous studies suggesting that there are links between the social behavior of parents and their children and that family experiences may be involved in the acquisition of peer relationship skills. The mechanisms by which such family influence might operate are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

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A simple progressive exercise test was performed before and after operation on five subjects undergoing mitral valve replacement and on five subjects undergoing aortic valve replacement. The responses of heart rate and ventilation were related to work rate )kilopond metres/min). The patients were also assessed clinically by the New York Heart Association grading and radiologically before each exercise test. The clinical grading was shown to be a poor guide to observed exercise tolerance, as the improvement noted in symptoms was not matched by the objective measurement of working capacity. Only two patients had normal exercise tolerance after surgery, although six of the ten patients claimed that they had no exertional dyspnoea after operation. The changes in simple ventilatory function tests before and after operation were generally small. We suggest that measurements of exercise tolerance before and after operation should be an essential part of heart valve replacement surgery.  相似文献   

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Cardiac transplantation, first introduced 30 years ago, has become a widely used and increasingly important procedure for treatment of truly end-stage heart disease. Current use is limited strictly by donor supply, making selection of appropriate recipients an important ethical and societal issue. Survival rates after transplantation rose in the 1980s with the use of cyclosporine and have remained relatively consistent since then, although recipients older than 65 years or younger than 1 year have lower survival rates than recipients of other ages. Although immunosuppressive drugs have helped establish cardiac transplantation as a successful procedure, risks of opportunistic infection and rejection, as well as coronary arteriopathy, have led to development of new immunosuppressive agents currently under study. Future alternatives to the current technology of cardiac allotransplantation may include xenotransplantation and/or nonbiological replacement of the heart with mechanical devices.  相似文献   

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Some inherent limitations to further technical improvement in film-screen mammography exist. Many of these limitations can be overcome effectively with digital mammography, in which image acquisition, display, and storage are performed independently, thus allowing the optimization of each. Presented is a brief background of digital and analog imaging with emphasis on the features and drawbacks of digital mammography systems. Image storage, processing, and display, computer-aided detection and diagnosis, as well as telemammography are also discussed.  相似文献   

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In the past decade, significant progress has been achieved in the battle against hepatitis B virus. In addition to the immunomodulating agents such as interferon-alpha and thymosin, many novel antiviral agents have been discovered, among which nucleoside analogues are the mainstay. New-generation compounds such as 3TC and famciclovir have shown promise in the treatment of patients chronically infected by this virus, and are on the line for approval. However, viral rebound after cessation of therapy still remains a major problem. Additionally, the reports on the drug resistance to these antiviral agents suggest that combination therapy will be the eventual strategy (Bartholomew et al., 1997; Tipples et al., 1996). Therefore, developments of safe and effective antiviral agents which do not cross-resist with currently available antiviral drugs are still much needed.  相似文献   

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Neuropeptide Y (NPY) is a hexatriacontapeptide amide that is now well characterized as a neuromodulator in the central nervous system (CNS). When infused into the CNS, NPY produces both anxiolytic and orexigenic effects. NPY's anxiolytic effects appear to be mediated through receptors in the central amygdala, whereas its orexigenic effects are localized in discrete hypothalamic nuclei. Both food restriction and food deprivation produce increased levels of the peptide in the hypothalamus that are ameliorated by refeeding. However, the effects of alcohol consumption/deprivation on NPY levels remain unknown. The present study sought to determine if brain NPY levels were affected by either alcohol exposure and/or correlated with genetic differences in preference for drinking alcohol. In the first experiment, NPY-like immunoreactivity (NPY-LI) was compared in alcohol-naive, alcohol-preferring (P), and nonpreferring (NP) rats. After tissue extraction, NPY-LI was measured by radioimmunoassay: amygdala, hippocampus, frontal cortex, hypothalamus, and caudate. P rats were found to have significantly lower NPY-LI in amygdala (F = 4.69, p < 0.04), hippocampus (F = 7.03, p < 0.01), and frontal cortex (F = 4.7, p < 0.04), compared with NP rats. In the second experiment, heterozygous Wistar rats were exposed to alcohol for 14 hr/day for 7 weeks in alcohol vapor chambers (mean blood alcohol concentrations = 180 mg%) or control chambers. At 7 weeks of alcohol exposure, no significant changes in NPY-LI in were found. At 1 month after ethanol withdrawal, however, the ethanol-exposed animals had significantly higher NPY-LI in the hypothalamus (F = 4.78, p < 0.04) when compared with the nonexposed controls. Taken together, these studies suggest that exposure to chronic ethanol may affect NPY-LI at the level of the hypothalamus in a fashion similar to food restriction, because 4 weeks after alcohol withdrawal, significantly higher NPY levels are found. In addition, differences in NPY-LI in limbic areas and frontal cortex between alcohol-naive P and NP rats suggest that NPY may also play a role in risk for the development of alcohol preference either by modulating the "tension-reduction" properties of alcohol or by influencing consummatory behaviors.  相似文献   

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CA Kuhn  CW Hanke 《Canadian Metallurgical Quarterly》1997,23(8):649-54; discussion 654-5
BACKGROUND: Malignant melanoma is increasing worldwide faster than any other cancer and the American lifetime risk is estimated to reach 1 in 75 by the year 2000. Active specific immunotherapy with vaccines is evolving as a promising new modality in the treatment of malignant melanoma. OBJECTIVE: To present a concise and understandable summary of the key molecular and clinical concepts of melanoma vaccines currently under investigation, the history that led to their development, and their anticipated clinical response. METHODS: The recent advances in the field of melanoma immunobiology and the newest experiment vaccines are reviewed. RESULTS: There is no effective melanoma vaccine that successfully treats or prevents melanoma. However, their use has been associated with regression or delayed disease progression in some cases. The minority of patients who do have a major clinical response to vaccine therapy experience an improvement in survival. Even in those patients in whom melanoma vaccines cannot improve survival, the paucity of severe side effects has provided a quality of life superior to standard multiagent chemotherapy. CONCLUSION: Melanoma vaccines are relatively safe immunotherapeutic modalities for the management of malignant melanoma. The clinical effectiveness of melanoma vaccines is unclear and adequately controlled studies need yet to be performed. Current melanoma vaccines manipulate antigen presentation networks and combine the best cellular and antibody antitumor immune response effective in mediating tumor protective immunity; these combination vaccines hold the most promise. The ideal melanoma vaccine will ultimately prevent melanoma.  相似文献   

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