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991.
BACKGROUND: Although botulism is rare, recognition of a possible case of this illness represents a public health emergency. To prevent more cases, prompt investigation must be done to determine whether illness is linked to commercial product or restaurant. Botulism can masquerade as other illnesses, and seemingly unlikely foods can harbor botulinum toxin. OBJECTIVE: To confirm the diagnosis and determine the cause and extent of an outbreak of botulism associated with food served at a delicatessen. DESIGN: Retrospective cohort study of patrons of the delicatessen; laboratory analysis of food, serum samples, and stool samples; and traceback of implicated food. SETTING: Community in Georgia. PARTICIPANTS: Patrons of the delicatessen. MAIN OUTCOME MEASURES: Botulinum toxin in food, serum, or stool and Clostridium botulinum in food and stools. RESULTS: 8 of 52 patrons (15%) met the case definition for botulism. In 4 of the 8 patrons, and illness other than botulism was initially diagnosed. Five of the 8 were hospitalized, and 1 died. Stool cultures from 4 patrons yielded type AC. botulinum, and two serum samples contained botulinum toxin. All ill persons ate food from the delicatessen on 1 October 1993. Of the 22 persons who ate at the delicatessen that day, all 8 ill persons but none of the 14 well persons ate a potato stuffed with meat and cheese sauce. An open can of cheese sauce contained type A botulinum toxin and yielded C botulinum on culture. Cheese sauce experimentally inoculated with C botulinum spores became toxic after 8 days at a temperature of 22 degrees C (room temperature). CONCLUSIONS: A commercial, canned cheese caused a botulism outbreak. This product readily becomes toxic when contaminated by C botulinum spores and left at room temperature. Mild botulism caused by unusual vehicles may be misdiagnosed. Botulism should be included in the differential diagnosis of persons with signs or symptoms of acute cranial nerve dysfunction.  相似文献   
992.
OBJECTIVE: To provide Canadian physicians with comprehensive, evidence-based guidelines for the nonpharmacologic management and prevention of gestational hypertension and pre-existing hypertension during pregnancy. OPTIONS: Lifestyle modifications, dietary or nutrient interventions, plasma volume expansion and use of prostaglandin precursors or inhibitors. OUTCOMES: In gestational hypertension, prevention of complications and death related to either its occurrence (primary or secondary prevention) or its severity (tertiary prevention). In pre-existing hypertension, prevention of superimposed gestational hypertension and intrauterine growth retardation. EVIDENCE: Articles retrieved from the pregnancy and childbirth module of the Cochrane Database of Systematic Reviews; pertinent articles published from 1966 to 1996, retrieved through a MEDLINE search; and review of original randomized trials from 1942 to 1996. If evidence was unavailable, consensus was reached by the members of the consensus panel set up by the Canadian Hypertension Society. VALUES: High priority was given to prevention of adverse maternal and neonatal outcomes in pregnancies with established hypertension and in those at high risk of gestational hypertension through the provision of effective nonpharmacologic management. BENEFITS, HARMS AND COSTS: Reduction in rate of long-term hospital admissions among women with gestational hypertension, with establishment of safe home-care blood pressure monitoring and appropriate rest. Targeting prophylactic interventions in selected high-risk groups may avoid ineffective use in the general population. Cost was not considered. RECOMMENDATION: Nonpharmacologic management should be considered for pregnant women with a systolic blood pressure of 140-150 mm Hg or a diastolic pressure of 90-99 mm Hg, or both, measured in a clinical setting. A short-term hospital stay may be required for diagnosis and for ruling out severe gestational hypertension (preeclampsia). In the latter case, the only effective treatment is delivery. Palliative management, dependent on blood pressure, gestational age and presence of associated maternal and fetal risk factors, includes close supervision, limitation of activities and some bed rest. A normal diet without salt restriction is advised. Promising preventive interventions that may reduce the incidence of gestational hypertension, especially with proteinuria, include calcium supplementation (2 g/d), fish oil supplementation and low-dose acetylsalicylic acid therapy, particularly in women at high risk for early-onset gestational hypertension. Pre-existing hypertension should be managed the same way as before pregnancy. However, additional concerns are the effects on fetal well-being and the worsening of hypertension during the second half of pregnancy. There is, as yet, no treatment that will prevent exacerbation of the condition. VALIDATION: The guidelines share the principles in consensus reports from the US and Australia on the nonpharmacologic management of hypertension in pregnancy.  相似文献   
993.
994.
The current AIDS epidemic has rekindled interest in the evolution of retroviruses and the development of resistance to infection. Retroviruses and their vertebrate hosts have coexisted for millions of years, during which time a variety of host defence mechanisms has evolved. One repeated strategy is to use endogenous retroviruses to combat infection by their exogenous relatives.  相似文献   
995.
A 5-year-old Caucasian male presented with early loss of multiple deciduous teeth. All the characteristics were consistent with the diagnosis of regional odontodysplasia (ROD). Significant initial findings included premature loss of multiple primary mandibular teeth and some malformed permanent teeth. The affected teeth showed hypoplastic enamel and dentin, short roots, and wide pulp chambers, and were localized in the mandibular dentition. Treatment objectives for this patient were to provide improved esthetics, restored chewing function, and space maintenance by the construction of a temporary prosthetic restoration. However, with limited tooth support and an unusual occlusal pattern, it is difficult to obtain satisfactory retention and esthetics with traditional prosthetic techniques. In this article we introduce an alternative method for fabricating a custom removable denture and discuss the prognosis of the malformed permanent dentition and further treatment plan.  相似文献   
996.
This article explores the relationship between sociopsychological factors, sexual activity, and sexual satisfaction in a sample of 1,216 elderly people (mean age = 77.3). Almost 30% had participated in sexual activity in the past month and 67% were satisfied with current level of sexual activity. Men are more likely to be sexually active, but less apt than women to be satisfied with their level of sexual activity. Regarding predictors of sexual activity, for men the strongest predictors were being younger and having more education. For women, the strongest predictor by far was being married. For both men and women the strongest predictors for satisfaction were being sexually active and having positive mental health scores. In summary, the main variables predicting sexual activity were being married, having more education, being younger, being male, and having good social networks. The main predictors for satisfaction with sexual activity were, in addition to being sexually active, being female, having good mental health, and better functional status.  相似文献   
997.
Prior studies have shown that, in some human tumour cells, increased expression of the multidrug resistance gene MDR1 can be induced in response to certain stress conditions such as a transient exposure to cytotoxic agents. Little is known about the possibility of increasing the expression of the recently cloned multidrug resistance-associated protein (MRP) in response to a transient exposure to cytotoxic drugs. In order to examine this possibility, we have used sensitive assays (RT-PCR, flow cytometry) and the sensitive large cell lung cancer cell line, COR-L23/P, and the revertant line (COR-L23/Rev), generated by growing the doxorubicin-selected, MRP-overexpressing resistant variant COR-L23/R without drug exposure for 24-28 weeks. COR-L23/Rev overexpresses MRP, but to a lesser extent than COR-L23/R. COR-L23/Rev rapidly recovered similar levels of MRP mRNA, protein expression, resistance and drug accumulation deficit as COR-L23/R after a 48-72 h exposure to cytotoxic concentrations of doxorubicin or vincristine but not cisplatin. The increase in MRP mRNA could only be detected 3 to 4 days after the transient exposure to drugs. However, when the parental line, COR-L23/P, was exposed to equitoxic doses of doxorubicin, vincristine or cisplatin, no increase in the levels of MRP mRNA could be observed at higher doses (5- to 10-fold the IC50) of doxorubicin or vincristine (but not of cisplatin), we detected a transient increase in the levels of MDR1 mRNA immediately after short-term exposure. In conclusion, we have shown that a human revertant lung cancer cell line (COR-L23/Rev) has the ability to recover quickly, similar levels of MRP expression and resistance as COR-L23/R after a transient exposure to the MDR-drugs doxorubicin and vincristine.  相似文献   
998.
The ability to discriminate between galactose and N- acetylgalactosamine, observed in some lectins, is crucial for their biological activity as well as their usefulness as tools in biology and medicine. However, the molecular basis of differential binding of lectins to these two sugars is poorly understood. Peanut agglutinin (PNA) is one of the few galactose-specific legume lectins which does not bind N- acetylgalactosamine at all and is, therefore, ideal for the study of the basis of specificity towards C-2 substituted derivatives of galactopyranosides. Examination of the three-dimensional structure of PNA in complex with lactose revealed the presence of both a longer loop and bulkier residues in the region surrounding the C-2 hydroxyl of the galactopyranoside ring, which can sterically prevent the accommodation of a bulky substituent in this position. One such residue, is a glutamic acid at position 129 which protrudes into the binding site and perhaps directly obstructs any substitution at the C-2 position. Two mutants in bacterially expressed PNA were therefore constructed. These were E129D and E129A, in which Glu129 was replaced by Asp and Ala, respectively. The specificity of the mutants for galactose, galactosamine, and N- acetylgalactosamine was examined through observing the inhibition of hemagglutination and binding of the lectin to immobilized asialofetuin. The results showed that the affinity of E129A and E129D for C-2-substituted derivatives of the galactose varies. The mutant E129D showed significant binding towards N- acetylgalactosamine, suggesting that the residue Glu 129 is crucial in imparting exclusive galactose-specificity upon PNA. This study not only attempts to provide an explanation for the inability of PNA to accommodate C-2-substituted derivatives at its primary subsite, but also seeks to present a basis for engineering lectins with altered specificities.  相似文献   
999.
1000.
OBJECTIVE: To review the findings of prospective controlled trials of antihypertensive treatment and determine whether the evidence they have provided is embodied satisfactorily in current national and international guidelines for hypertension management. MANAGEMENT GUIDELINES: Conventional guidelines all advise prompt treatment of moderate-to-severe hypertension and treatment of even mild hypertension in subjects with cardiovascular disease, target organ damage or diabetes, and in the elderly; and treatment of isolated systolic hypertension in the elderly. All acknowledge that evidence for efficacy and safety of treatment is strongest for thiazide diuretics and beta-blockers. UNCOMPLICATED MILD HYPERTENSION: Conventional guidelines all emphasize the importance of long-term blood pressure, measured over some months, for treatment decisions. However the blood pressure for routine treatment varies from 160/100 mmHg (British Hypertension Society) to 140/90 mmHg (Joint National Committee V). This dictates very large differences in the number of patients to be treated to prevent a cardiovascular disease event and in the proportion of the population to be treated, yet the reasons for these differences are not explicit. None of the conventional guidelines is entirely satisfactory. The more conservative British Hypertension Society policy may leave untreated some middle-aged men who ought to be treated. The more aggressive Joint National Committee V policy will lead to treatment of some young subjects who have only a remote chance of benefit, at very high cost, and possibly with adverse harm-benefit consequences. RISK-BASED GUIDELINES: Guidelines developed in New Zealand target absolute cardiovascular disease risk in mild hypertension and have the potential to correct this shortcoming of conventional guidelines. However they require further consideration as regards the number needed to treat which is acceptable to well-informed patients, the appropriate estimate of relative cardiovascular disease risk reduction by treatment in mild hypertension, the pattern of treatment which will emerge and their acceptability in ordinary practice. CONCLUSION: Comparative evaluation will be needed to determine whether the outcome is better with conventional guidelines, which are simple but at the expense of accuracy, or with risk-targeted guidelines, which are more accurate but at the expense of simplicity.  相似文献   
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