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Carcinoma of the breast is the most frequent cause of death in women aged between approximately 38 and 50 years. At present, 1 out of 14 women in Germany and 1 out of 9 in America suffer from breast cancer within a life time. To date, modern methods of treatment and hormone therapy have only been able to increase long-term survival by about 12%. Trials have shown that early diagnosis alone has been able to increase survival from 20% to 50%. Early diagnosis proved to be most effective when clinical examination plus mammography in two planes was carried out annually. An increase in survival has been achieved in post-menopausal women as a result of screening. 22 percent of breast cancers were detected at a curable in situ stage by means of screening. Even after a limited screening program of 4 examination cycles the increase in survival rate over 15-20 years was significant.  相似文献   
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Stimulus control was established in rats using either 8-hydroxy-2-[di-n-propylamino]tetralin (DPAT) (0.2 mg/kg) or yohimbine (3 mg/kg). Tests were then conducted with purported antagonists at 5-hydroxytryptamine1A (5-HT1A) receptors. Drugs studied were NAN-190, [+/-]-pindolol, and [-]-alprenolol. In addition, each drug was characterized in terms of its affinity for 5-HT1A and alpha 2-adrenoceptors by means of radioligand binding techniques. None of the antagonists tested provided complete blockade of the stimulus effects of either DPAT or yohimbine. However, [+/-]-pindolol produced a statistically significant intermediate degree of antagonism of both DPAT and yohimbine. The affinities of DPAT, yohimbine, and NAN-190 for the 5-HT1A and alpha 2-adrenergic receptors, respectively, were sufficiently high to lead to some ambiguity of interpretation of the behavioral data. However, the results with [+/-]-pindolol, which has high affinity for the 5-HT1A receptor (34 nM) and negligible affinity for the alpha 2-adrenoceptor (24,600 nM), indicate that a significant component of yohimbine-induced stimulus control is mediated by the 5-HT1A receptor.  相似文献   
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Infectious agents, including viruses, bacteria, and parasites, can be transmitted by human blood products. Of major importance are viruses such as human immunodeficiency virus types 1 and 2 (HIV-1/2), hepatitis B virus (HBV), hepatitis C virus (HCV), and human T-cell lymphotropic virus types I and II (HTLV-I/II). Also, other viruses such as cytomegalovirus, Epstein-Barr virus, human parvovirus B19, and hepatitis A and G viruses can be transmitted by blood products. Various methods are used to prevent transmission of blood-borne agents to recipients, such as donor selection, testing donated blood for various infectious agents, and viral inactivation of plasma derivatives. With all these precautionary measures, the estimated risk for infection by screened blood components in Europe and the United States is approximately 1 in 50,000 to 1.6 million (for HBV, HCV, and HIV-1/2) transfused blood components. In the future, the safety of blood components may be increased by testing donated blood by nucleic acid amplification techniques and by photochemical decontamination of cellular blood components.  相似文献   
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