Functional antagonism between dopamine and noradrenaline within the caudate nucleus of cats: A phenomenon of rhythmically changing susceptibility

Two aspects of the functional interaction between the neurotransmitters dopamine (DA) and noradrenaline (NE) were studied: the role of NE within brain structures marked by DA terminals and the occurrence of annual changes in their functional interaction. The behavioral changes produced by single or combined administration of DA, (3,4-dihydroxyphenylamino)-2-imidazoline (DPI), ergometrine, ET-495, NE, oxymetazoline, and phentolamine into the caudate nucleus of freely moving cats were analyzed. NE and oxymetazoline produced effects that differed from those elicited by DA or DPI. NE-dependent effects were antagonized by phentolamine, and DA- or DPI-induced effects were antagonized by ergometrine. Ergometrine, NE, and oxymetazoline were effective in November, December, and January, lost their effectiveness in March, April, and May, regained it in July, and lost it again in August, September, and October. The annual pattern of DA, DPI, and phentolamine on the other hand, was just the opposite. DA agonists suppressed NE- or oxymetazoline-induced effects, while the DA antagonist suppressed phentolamine-induced effects. Noradrenergic agents were unable to modulate the DA-dependent effects under certain circumstances. It is concluded that (1) NE-dependent processes within the feline caudate nucleus inhibit DA-dependent processes within this structure, and (2) there exists a reciprocal relationship between the annual changes in the feline's susceptibility to DA, DPI, and phentolamine, on the one hand, and to ergometrine, NE, and oxymetazoline, on the other hand.     

Excel97在药物分析中的应用

目的：在药物分析中,电子表格软件ＭｉｃｒｏｓｏｆｔＥｘｃｅ１９７ｆｏｒ Ｗｉｎｄｏｗｓ。方法：利用Ｅｘｃｅｌ的数据处理功能,进行药物的图表绘制、数据计算和统计处理,回归分析,特别是计算分析,并可建立分析数据库。结果和结论：Ｅｘｃｅｌ操作简单,功能强大,数据分析工作直观。     

辛伐他汀(舒降之)治疗原发性高胆固醇血症的临床比较研究

目的：比较国产辛伐他汀与进口辛伐他汀治疗原发性高胆固醇血症的疗效及安全性。方法：采用开放区组随机对照、多中心的临床设计。１５０例高胆 固醇血症病人分为验证组（５０例）、对照组（４８例）和开放组（５２例）,剂量均为每晚顿服１０ｍｇ,服药８周。结果：验证组与对照组服药前后比较,血清总胆 固醇（ＴＣ）分别降低２６．３６％和２８．３％,低密度脂蛋白胆固醇（ＬＤＬ－Ｃ）分别降低３３．１７％和３５．５１％;验     

Quantitative and qualitative differences in the metabolism of 14C-1,3-butadiene in rats and mice: relevance to cancer susceptibility.

1,3-Butadiene (butadiene) is a potent carcinogen in mice, but not in rats. Metabolic studies may provide an explanation of these species differences and their relevance to humans. Male Sprague-Dawley rats and B6C3F1 mice were exposed for 6 h to 200 ppm [2,3-14C]-butadiene (specific radioactivity [sa] 20 mCi/mmol) in a Cannon nose-only system. Radioactivity in urine, feces, exhaled volatiles and 14C-CO2 were measured during and up to 42 h after exposure. The total uptake of butadiene by rats and mice under these experimental conditions was 0.19 and 0.38 mmol (equivalent to 3.8 and 7.5 mCi) per kg body weight, respectively. In the rat, 40% of the recovered radioactivity was exhaled as 14C-CO2, 70% of which was trapped during the 6-h exposure period. In contrast, only 6% was exhaled as 14C-CO2 by mice, 3% during the 6-h exposure and 97% in the 42 h following cessation of exposure. The formation of 14C-CO2 from [2,3-14C]-labeled butadiene indicated a ready biodegradability of butadiene. Radioactivity excreted in urine accounted for 42% of the recovered radioactivity from rats and 71% from mice. Small amounts of radioactivity were recovered in feces, exhaled volatiles and carcasses. Although there was a large measure of commonality, the exposure to butadiene also led to the formation of different metabolites in rats and mice. These metabolites were not found after administration of [4-14C]-1,2-epoxy-3-butene to animals by i.p. injection. The results show that the species differences in the metabolism of butadiene are not simply confined to the quantitative formation of epoxides, but also reflect a species-dependent selection of metabolic pathways. No metabolites other than those formed via an epoxide intermediate were identified in the urine of rats or mice after exposure to 14C-butadiene. These findings may have relevance for the prediction of butadiene toxicity and provide a basis for a revision of the existing physiologically based pharmacokinetic models.     

Diet and cancer prevention: the fiber first diet

Diet can play a major role in cancer prevention. The international differences in cancer incidence are largely accounted for by lifestyle practices that include nutrition, exercise, and alcohol and tobacco use. About 50% of cancer incidence and 35% of cancer mortality in the U.S., represented by cancers of the breast, prostate, pancreas, ovary, endometrium, and colon, are associated with Western dietary habits. Cancer of the stomach, currently a major disease in the Far East, relates to distinct, specific nutritional elements such as excessive salt intake. For these cancers, information is available on possible initiating genotoxic factors, promoting elements, and prophylactic agents. In general, the typical diet in the United States contains low levels of the potent carcinogenic agents, heterocyclic amines, formed during the cooking of meats. It provides only about half the potent appropriate fiber intake and is high in calories. About twice as many calories as would be desirable come from fat, certain kinds of which enhance the development of cancers. Other foods with functional properties, such as soy products and tea, can be beneficial. To achieve reduction in risk of certain cancers, diet must be optimized, primarily to reduce caloric intake and the fat component. The latter should be 20% or less of total caloric intake and fiber should be increased to 25- 35 g per day for adults. One approach to achieving these goals is the Fiber First Diet, a diet designed around adequate fiber intake from grains, especially cereals, vegetables, legumes, and fruits, which thereby reduces both calorie and fat intake. Such dietary improvements will not only reduce cancer and other chronic disease risks, but will contribute to a healthy life to an advanced age. A corollary benefit is a lower cost of medical care.      

The constipation-inducing potential of morphine and transdermal fentanyl

Constipation is an almost universal side-effect associated with chronic opioid analgesia. The resulting discomfort can for some patients be more severe than the pain itself, leading to a reduction of analgesic use and consequently to increased pain. Clinical trials consistently show less constipation in patients treated with transdermal fentanyl than in patients receiving oral morphine. Several reasons can be identified for this finding: owing to its higher lipophilicity, fentanyl penetrates the blood-brain barrier more easily and lower dosing is possible; owing to the transdermal route of administration of fentanyl, comparatively less opioid is available in the gastrointestinal tract to block local opioid receptors; finally, the transdermal route of administration leads to stable plasma levels of fentanyl over 72 h and hence minimises the probability of overdosing that can occur with multiple daily dosing. Further research is needed to establish whether these effects can also be extrapolated to other peripheral effects of opioids such as nausea and vomiting.     

Percutaneous removal of residual intrahepatic stones

In the Orient there is a high frequency of residual intrahepatic stones after biliary tract surgery. Percutaneous removal of residual intrahepatic stones was attempted in a group of 74 patients. Stones were exclusively intrahepatic in 57 patients, whereas 17 patients also had stones in the common bile duct. Biliary strictures were present in 60 cases (81%). A combination of techniques was used, including preshaped angulated catheters, irrigation-suction, balloon dilation of strictures, and crushing of large stones. In 36 cases all stones were removed and in 14 cases most stones were removed, for a success rate of 67.6%. Biliary stricture was the factor most often responsible for failure.     

Activation and complexation of protein C and cleavage and decrease of protein S in plasma of patients with intravascular coagulation

Activated protein C (APC) is inhibited by two major plasma inhibitors (PCIs). To find evidence for in vivo complexation of APC, immunoblotting studies were performed on plasmas of 85 patients with suspected disseminated intravascular coagulation (DIC). Samples from 62 of these patients contained 5% to 35% of protein C antigen in APC:inhibitor complexes, indicating that protein C activation and inhibition had occurred. In 24 normal plasmas, no detectable APC:PCI complexes were observed (less than 5%). Patients with higher levels of complexes had more abnormal coagulation test data for DIC. The major band of APC complexes detected by anti-protein C antibodies did not react with antibodies to the heparin-dependent protein C inhibitor (PCI- 1) previously described. Rather, APC was complexed with another recently described plasma protein C inhibitor, PCI-2. Immunoblotting studies for protein S, the cofactor for APC, revealed that the majority of the DIC patient plasmas contained a higher than normal proportion of protein S in cleaved form, suggesting that protein S may have been proteolytically inactivated. Protein S total antigen levels were also found to be low in DIC patients, excluding those with malignancy. These studies support the hypothesis that the protein C pathway is activated during DIC.     

Lipohemarthrosis of the knee: a review of recent experiences

The radiographs of 268 patients with knee trauma were retrospectively reviewed. In 15 patients with intraarticular fracture, the images demonstrated fat-fluid levels. In 28 other patients with intraarticular fracture, only joint effusion without a fat-fluid level was depicted. The presence of a fat-fluid level in the knee indicated fracture in all patients in whom it was seen. The absence of such a level, however, did not exclude intraarticular fracture.     

Scedosporium endophthalmitis: two fatal disseminated cases of Scedosporium infection presenting with endophthalmitis

The incidence of disseminated infection with Scedosporium species is increasing in patients with haematological malignancy. Two fatal cases are reported of patients with acute myeloid leukaemia and neutropenia who presented with Scedosporium endophthalmitis. Diagnosis of fungal infection was delayed as blood and vitreous cultures were positive only after 3 days in patient 1 and blood culture was positive at 7 days in patient 2. Despite antifungal therapy with amphotericin B and additional fluconazole in patient 2, both patients died of overwhelming fungal septicaemia. Post‐mortem examination of the right globe in patient 1 showed haemorrhagic necrotizing chorioretinitis with numerous fungal hyphae in choroidal vessels, choroid, retina and vitreous. Scedosporium species are often resistant to conventional antifungal therapy including amphotericin B. Diagnosis is difficult and mortality in disseminated infection is high.