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VJ Barrett DA Leiby JL Odom MM Otani JD Rowe JT Roote KF Cox KR Brown JA Hoiles A Saez-Alquézar JF Turrens 《Canadian Metallurgical Quarterly》1997,108(5):499-503
The ultrastructure of alpha-bacteroids in relation to the fat-body cells of the lantern bug Pyrops candelaria was described. The fat-body-cell cytoplasm contained numerous mitochondria, rough endoplasmic reticula, vacuoles, and storage granules. Its nucleus had scattered chromatin materials. The alpha-bacteroid was enveloped by three membrane layers, namely, the plasma membrane, the cell wall, and the membrane envelope. Its cytoplasm contained amorphous dense bodies. The bacteroid reproduced by binary fission. Tracheoles were also found among fat-body cells. 相似文献
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A workshop to describe and then seek possible causes for the increased stroke mortality in the southeastern United States briefly considered 30 suspected correlates and discussed in more detail the 10 thought to be most likely. Recent age-adjusted stroke mortality rates in adults from industrialized countries reveal marked geographic differences. Age-adjusted statewide stroke mortality rates also differ, and they are higher in the Southeast than elsewhere in the United States. For five southeastern coastal states in the heart of the "Stroke Belt," excess stroke mortality has been present at least since 1930. In a 20-year follow-up of 10,000 veterans, the Stroke Belt had a 25% increase in all-cause mortality and congestive heart failure. A potential cause of increased fatal stroke included hypertension, which was more frequent in the Stroke Belt. No consistent patterns of lifestyle differences or of differences in potassium or calcium intake seemed to explain the higher rates of fatal strokes in the Stroke Belt; however, detailed investigations of smaller populations in localized areas seem warranted. Some data suggest a relationship between socioeconomic status and the Stroke Belt effect. Other differences in the Southeast that could explain, at least partially, the Stroke Belt effect include presence of soft water throughout most of the area, decreased antioxidant intake, and differences in the use of medical care and in the response to antihypertensive drugs. On the basis of available information, the three most likely explanations or partial explanations for the Stroke Belt are increased levels of blood pressure, localized differences in socioeconomic status, and toxic environmental factor(s). Two major recommendations were made: (1) to encourage both patient and caregiver to use all currently available means of decreasing morbidity and mortality by controlling blood pressures at or below normal levels and by reducing other risk factors and (2) to seek precise information about relationships of identified possible causes of increased morbidity and mortality in the Stroke Belt. 相似文献
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The small intestine, large intestine, and cecum of 975 white-tailed deer (Odocoileus virginianus) from 83 localities in 13 southeastern states were examined for nematodes. In order of prevalence, the following parasites were found: Capillaria bovis, Eucyathostomum webbi, Monodontus louisianensis, Nematodirus odocoilei, Oesophagostomum venulosum, Trichuris sp, Cooperia punctata, Trichostrongylus longispicularis, Strongyloides sp, Cooperia oncophora, Cooperia spatulata, Cooperia sp, and Trichostrongylus calcaratus. Over one-half of the deer examined were free of intestinal nematodes, and most infected deer harbored few parasites. Of the most prevalent species, C bovis, N odocoilei, O venulosum, and Trichuris sp were widely distributed, whereas M louisianensis and E webbi were restricted in distribution. Severe pathogenicity was associated with only heavy Strongyloides sp infections in 2 penned deer. The findings of this study suggested that white-tailed deer of the Southeast are insignificant in the epizootiology of important intestinal nematodes of domestic livestock. 相似文献
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The importance of atmospheric odors for homing pigeon navigation was tested using birds from a loft located in Savannah, GA, in the southeastern United States. When released from a familiar training site, control pigeons and pigeons given intranasal injections of zinc sulfate to produce anosmia both displayed good homeward orientation and homed quickly. When released from three unfamiliar release sites, in contrast, control birds tended to orient southeast, while zinc sulfate-treated birds were more likely to fly northwest. More importantly, while the majority of control pigeons returned to the home loft, few of the zinc sulfate-treated birds returned. The good performance of both groups from the familiar site indicates that zinc sulfate treatment does not impair the general motor ability or motivation of homing pigeons. Therefore, the observed impairment in homing success of the zinc sulfate-treated pigeons from the unfamiliar locations presumably reflects an impaired ability to use atmospheric odors to navigate home. As such, the data support the hypothesis that successful homing pigeon navigation is based on the perception of atmospheric odors and that olfactory navigation is the primary mechanism used by pigeons over a broad range of geographic areas to approximate their relative position with respect to home from unfamiliar locations. 相似文献
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CH Jagoe B Arnold-Hill GM Yanochko PV Winger IL Brisbin 《Canadian Metallurgical Quarterly》1998,213(1-3):255-262
Mercury methylation may be enhanced in wetlands and humic-rich, blackwater systems that crocodiles and alligators typically inhabit. Given their high trophic level and long life-spans, crocodilians could accumulate significant burdens of Hg. Our objectives were to survey Hg concentrations in alligators from several areas in the southeastern United States to test their utility as sentinels of Hg contamination, to examine relationships among Hg concentrations in various tissues and to look for any differences in tissue Hg concentrations among locations. We measured total Hg concentrations in alligators collected in the Florida Everglades (n = 18), the Okefenokee National Wildlife Refuge, Georgia (n = 9), the Savannah River Site (SRS), South Carolina (n = 49) and various locations in central Florida (n = 21), sampling tissues including blood, brain, liver, kidney, muscle, bone, fat, spleen, claws and dermal scutes. Alligators from the Everglades were mostly juvenile, but Hg concentrations in tissues were high (means: liver 41.0, kidney 36.4, muscle 5.6 mg Hg/kg dry wt.). Concentrations in alligators from other locations in Florida were lower (means: liver 14.6, kidney 12.6, muscle 1.8 mg Hg/kg dry wt.), although they tended to be larger adults. Alligators from the Okefenokee were smallest and had the lowest Hg concentrations (means: liver 4.3, kidney 4.8, muscle 0.8 mg Hg/kg dry wt.). SRS alligators had the greatest size range and intermediate Hg levels (means: liver 14.9, muscle 4.8 mg Hg/kg dry wt.). At some locations, alligator length was correlated with Hg concentrations in some internal organs. However, at three of the four locations, muscle Hg was not related to length. Tissue Hg concentrations were correlated at most locations however, claw or dermal scute Hg explained less than 74% of the variation of Hg in muscle or organs, suggesting readily-obtained tissues, such as scutes or claws, have limited value for non-destructive screening of Hg in alligator populations. 相似文献
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JM Melhorn 《Canadian Metallurgical Quarterly》1998,(351):107-126
Cumulative trauma disorders account for 56% of all occupational injuries. Currently, occupational injuries affect 15% to 20% of all Americans. The United States government predicts that by the year 2000, 50% of the American workforce will have occupational injuries annually and 50 cents of every dollar will be spent on cumulative trauma disorders. There is common agreement on the need for reduction of cumulative trauma disorders in the workplace. However, there is little agreement on the appropriate definition for musculoskeletal pain that occurs in the workplace, or the ergonomic and epidemiologic model for cumulative trauma disorders, or on the specific exposure relationships of the individual, by the job, and occurring in the workplace. The previous treatments for, and the natural history of, cumulative trauma disorders in other countries gives some insight into the possible future of cumulative trauma disorders for the United States. Until research can provide specific dose and exposure relationships for the individual, prevention remains the best treatment for cumulative trauma disorders in the workplace. 相似文献
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OBJECTIVE: The authors examined the barriers to receipt of medical services among people reporting mental disorders in a representative sample of U.S. adults. METHOD: The sample was drawn from adults who responded to the 1994 National Health Interview Survey (N=77,183). The authors studied the association between report of a mental disorder and 1) access to health insurance and a primary provider, and 2) actual receipt of medical care. Multivariate techniques were used to model problems with access as a function of mental disorders, controlling for demographic, insurance, and health variables. RESULTS: While people who reported mental disorders showed no difference from those without mental disorders in likelihood of being uninsured or of having a primary care provider, they were twice as likely to report having been denied insurance because of a preexisting condition or having stayed in their job for fear of losing their health benefits. Among respondents with insurance, those who reported mental illness were no less likely to have a primary care provider but were about two times more likely to report having delayed seeking needed medical care because of cost or having been unable to obtain needed medical care. CONCLUSIONS: People who reported mental disorders experienced significant barriers to receipt of medical care. Efforts to measure and improve access to health care for this population may need to go beyond simply providing insurance benefits or access to general medical providers. 相似文献
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OBJECTIVE: To determine the extent to which incorporating fat-modified foods into a food frequency questionnaire influences the agreement of energy and nutrient estimates with estimates obtained from food records. DESIGN: Subjects completed four 2-day food records at 3-month intervals. At the end of the recording period, a food frequency questionnaire was administered to assess usual daily intake during the preceding year. SUBJECTS/SETTING: One hundred and three subjects selected from a population-based sample of adults participating in the Beaver Dam Eye Study. STATISTICAL ANALYSES PERFORMED: Subjects were categorized into three groups on the basis of their frequency of consumption of fat-modified foods. For each group, correlations were calculated between food record estimates and estimates obtained from the original food frequency questionnaire, the original with a low-fat option, and the fat-modified questionnaire. RESULTS: For persons categorized as high consumers of fat-modified foods, incorporating questions regarding the consumption of these products resulted in higher correlations with food record estimates (original vs fat-modified version) for percentage of energy from total fat (.32 vs .47), saturated fat (.20 vs .41), oleic acid (.32 vs .50), and linoleic acid (.40 vs .46). High consumers differed in several characteristics that could be associated with disease risk (eg, higher ratios of serum total cholesterol to high-density lipoprotein cholesterol). CONCLUSIONS: Failure to account for the consumption of fat-modified foods in epidemiologic studies may result in misclassification of fat exposures. Because patterns of misclassification could be different for those at risk for disease, results of epidemiologic studies could be biased if these foods are excluded. Thus, incorporating fat-modified foods into food frequency questionnaires will improve the ability of researchers to correctly classify fat exposures and to evaluate potentially important relationships between fat intake and disease risk. 相似文献
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AT Geronimus J Bound TA Waidmann MM Hillemeier PB Burns 《Canadian Metallurgical Quarterly》1996,335(21):1552-1558
BACKGROUND: Although the general relations between race, socioeconomic status, and mortality in the United States are well known, specific patterns of excess mortality are not well understood. METHODS: Using standard demographic techniques, we analyzed death certificates and census data and made sex-specific population-level estimates of the 1990 death rates for people 15 to 64 years of age. We studied mortality among blacks in selected areas of New York City, Detroit, Los Angeles, and Alabama (in one area of persistent poverty and one higher-income area each) and among whites in areas of New York City, metropolitan Detroit, Kentucky, and Alabama (one area of poverty and one higher-income area each). Sixteen areas were studied in all. RESULTS: When they were compared with the nationwide age-standardized annual death rate for whites, the death rates for both sexes in each of the poverty areas were excessive, especially among blacks (standardized mortality ratios for men and women in Harlem, 4.11 and 3.38; in Watts, 2.92 and 2.60; in central Detroit, 2.79 and 2.58; and in the Black Belt area of Alabama, 1.81 and 1.89). Boys in Harlem who reached the age of 15 had a 37 percent chance of surviving to the age of 65; for girls, the likelihood was 65 percent. Of the higher-income black areas studied, Queens--Bronx had the income level most similar to that of whites and the lowest standardized mortality ratio (men, 1.18; women, 1.08). Of the areas where poor whites were studied, Detroit had the highest standardized mortality ratios (men, 2.01; women, 1.90). On the Lower East Side of Manhattan, in Appalachia, and in Northeast Alabama, the ratios for whites were below the national average for blacks (men, 1.90; women, 1.95). CONCLUSIONS: Although differences in mortality rates before the age of 65 between advantaged and disadvantaged groups in the United States are sometimes vast, there are important differences among impoverished communities in patterns of excess mortality. 相似文献
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Brener Nancy D.; Hassan Sohela Sabur; Barrios Lisa Cohen 《Canadian Metallurgical Quarterly》1999,67(6):1004
This study analyzed data from the 1995 National College Health Risk Behavior Survey (NCHRBS) to assess the prevalence of suicidal ideation among college students in the United States and to examine the association between suicidal ideation and substance use in this population. The NCHRBS used a mail questionnaire to assess health-risk behaviors in a nationally representative sample of undergraduate students. During the 12 months preceding the survey, 10% of the students had seriously considered attempting suicide. When controlling for demographic characteristics, the analysis showed that students who had considered suicide were at increased odds of using tobacco, alcohol, and illegal drugs. These results suggest that colleges and universities should establish suicide prevention programs that also address the related problem of substance use. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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CONTEXT: Behaviors that result in potential exposure to human immunodeficiency virus (HIV) usually begin in adolescence or young adulthood, but trends in HIV incidence in young people remain unclear. OBJECTIVE: To estimate trends in HIV incidence in teenagers and young adults. DESIGN AND SETTING: Back-calculation of past HIV incidence in persons born between 1960 and 1974 using US national acquired immunodeficiency syndrome (AIDS) incidence data and estimates of the distribution of times between HIV infection and AIDS. MAIN OUTCOME MEASURES: Incidence and prevalence of HIV in 1988 and 1993 in persons aged 20 and 25 years, respectively, in each of those years. RESULTS: As of January 1993, about 22000 men and 11000 women aged 18 to 22 years were living with HIV infection in the United States. Homosexual contact was the leading route of infection among young men. Heterosexual contact was the leading route of infection among young women. The HIV incidence attributed to homosexual contact or injection drug use decreased among persons aged 20 and 25 years between 1988 and 1993, but HIV incidence attributed to heterosexual contact was stable or increasing. Notably, in men aged 20 and 25 years, HIV prevalence declined by about 50% in white men but was relatively stable in black and Hispanic men. In contrast, HIV prevalence in women aged 20 and 25 years rose by 36% and 45%, respectively, because of increasing heterosexual transmission. Overall, HIV prevalence in persons aged 20 and 25 years declined by only 14% between 1988 and 1993. CONCLUSIONS: In young persons, HIV incidence in homosexual men and injection drug users was slowing by 1993; this favorable trend was offset by increasing heterosexual transmission, especially in minorities. 相似文献
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To resolve the population genetic structure and phylogeography of the West Indian manatee (Trichechus manatus), mitochondrial (mt) DNA control region sequences were compared among eight locations across the western Atlantic region. Fifteen haplotypes were identified among 86 individuals from Florida, Puerto Rico, the Dominican Republic, Mexico, Columbia, Venezuela, Guyana and Brazil. Despite the manatee's ability to move thousands of kilometers along continental margins, strong population separations between most locations were demonstrated with significant haplotype frequency shifts. These findings are consistent with tagging studies which indicate that stretches of open water and unsuitable coastal habitats constitute substantial barriers to gene flow and colonization. Low levels of genetic diversity within Florida and Brazilian samples might be explained by recent colonization into high latitudes or bottleneck effects. Three distinctive mtDNA lineages were observed in an intraspecific phylogeny of T. manatus, corresponding approximately to: (i) Florida and the West Indies; (ii) the Gulf of Mexico to the Caribbean rivers of South America; and (iii) the northeast Atlantic coast of South America. These lineages, which are not concordant with previous subspecies designations, are separated by sequence divergence estimates of d = 0.04-0.07, approximately the same level of divergence observed between T. manatus and the Amazonian manatee (T. inunguis, n = 16). Three individuals from Guyana, identified as T. manatus, had mtDNA haplotypes which are affiliated with the endemic Amazon form T. inunguis. The three primary T. manatus lineages and the T. inunguis lineage may represent relatively deep phylogeographic partitions which have been bridged recently due to changes in habitat availability (after the Wisconsin glacial period, 10 000 B P), natural colonization, and human-mediated transplantation. 相似文献
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GV Doern AB Brueggemann M Blocker M Dunne HP Holley KS Kehl J Duval K Kugler S Putnam A Rauch MA Pfaller 《Canadian Metallurgical Quarterly》1998,27(4):757-761
Emu antibody responses to avian influenza virus (AIV) infection were evaluated by the competitive enzyme-linked immunosorbent assay (C-ELISA), agar gel immunodiffusion (AGID) and hemagglutination inhibition (HI) tests. All birds infected with AIV H5N1, H5N3, or H7N7 developed antinucleoprotein (NP) antibodies as early as 7 days postinfection as detected by the C-ELISA. The responses lasted 49 days for the emus receiving H5N3 and at least 56 days for emus receiving the other two viruses. By evaluating 50 emu field serum samples, the C-ELISA was found more sensitive than the AGID test for the detection of anti-NP antibodies. This study indicates that emus experimentally infected with AIV developed antibody responses that can be detected by C-ELISA, AGID, and HI tests. The results from this and our previous studies demonstrate the use of the C-ELISA as a substitute for the AGID test in a routine serodiagnostic screening for detection of antibodies to AIV infection in multiple avian species. 相似文献
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JD Woods MN Turenne RL Strawderman EW Young RA Hirth FK Port PJ Held 《Canadian Metallurgical Quarterly》1997,30(1):50-57
OBJECTIVES: To investigate: (i) if early psychosocial intervention after cystectomy for bladder cancer can assist psychosocial rehabilitation; (ii) if the outcome of such intervention correlates with the patient's psychological defensive strategies as revealed with the meta-contrast technique (MCT); and (iii) if the patient's general philosophical outlook is important in this context. PATIENTS AND METHODS: Of 50 patients who had undergone radical cystectomy for bladder cancer, 17 received an ileal conduit, 17 a continent urinary reservoir with abdominal stoma and 16 an orthotopic neobladder. Twenty-four of the patients were randomized to psychosocial intervention, comprising weekly counselling 4-9 weeks after surgery. All patients were then evaluated with the Sickness-Impact Profile (SIP) standard questionnaire and the MCT (a projective test of percept-genetic model) was used to reflect individual defensive strategies at the subconscious or unconscious level. The patient's general philosophical outlook was recorded before and after surgery. RESULTS: There was no significant difference in the results of the SIP between the intervention and the non-intervention group, as a whole or in its psychosocial dimension. However, intervention benefited patients with continent cutaneous diversion, whose scores on the psychosocial SIP dimension were lower than in the groups with ileal conduit diversion or orthotopic bladder replacement (P < 0.05). The MCT analysis of defensive strategies identified three clusters of patients characterized mainly by isolation and repression, repression and stereotypy or sensitivity and stereotypy. Analysis for cluster identification showed no significant SIP score differences between intervention and non-intervention groups. In an analysis of single defensive strategies, stereotypy was associated with higher total SIP score, but not significantly. Three clusters of philosophical outlook were identified; in one cluster, characterized by a belief in a supernatural power and philosophical interest, the psychosocial SIP scores were lower in the patients who obtained emotional support and the reverse in a cluster with contrary attitudes, although neither differences were significant. CONCLUSION: Psychosocial intervention assisted the psychosocial rehabilitation of patients with continent cutaneous urinary diversion. Defensive strategies and philosophical outlook generally did not influence the outcome of intervention. However, such programmes may be helpful for some patients, mainly those with a basically pessimistic disposition, a general interest in philosophical questions and often using defensive strategies of stereotypy and repression. 相似文献
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PURPOSE: Identification of prognostic factors in patients with malignant pleural mesothelioma based on prospectively collected international data. PATIENTS AND METHODS: From October 1984 to October 1993, 204 eligible adult patients with malignant pleural mesothelioma were entered into five consecutive prospective European Organization for Research and Treatment of Cancer (EORTC) phase II clinical trials designed to assess the efficacy of various anticancer drugs (mitoxantrone, epidoxorubicin, etoposide, and paclitaxel). The Cox model was used to assess 13 factors related to biology and disease history with respect to survival. RESULTS: The median survival duration was 12.6 months from diagnosis and 8.4 months from trial entry. In the multivariate analysis, poor prognosis was associated with a poor performance status, a high WBC count, a probable/possible histologic diagnosis of mesothelioma, male gender, and having sarcomatous tissue as the histologic subtype. Taking these five factors into consideration, patients were classified into two groups: a good-prognosis group (1-year survival rate, 40%; 95% confidence interval [CI], 30% to 50%) and a poor-prognosis group (1-year survival, 12%; 95% CI, 4% to 20%). CONCLUSION: These results may help to design new clinical trials in pleural mesothelioma by selecting more homogenous groups of patients. 相似文献
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Estimates of the prevalence of arthritis and selected musculoskeletal disorders in the United States 总被引:3,自引:0,他引:3
RC Lawrence CG Helmick FC Arnett RA Deyo DT Felson EH Giannini SP Heyse R Hirsch MC Hochberg GG Hunder MH Liang SR Pillemer VD Steen F Wolfe 《Canadian Metallurgical Quarterly》1998,41(5):778-799
OBJECTIVE: To provide a single source for the best available estimates of the national prevalence of arthritis in general and of selected musculoskeletal disorders (osteoarthritis, rheumatoid arthritis, juvenile rheumatoid arthritis, the spondylarthropathies, systemic lupus erythematosus, scleroderma, polymyalgia rheumatica/giant cell arteritis, gout, fibromyalgia, and low back pain). METHODS: The National Arthritis Data Workgroup reviewed data from available surveys, such as the National Health and Nutrition Examination Survey series. For overall national estimates, we used surveys based on representative samples. Because data based on national population samples are unavailable for most specific musculoskeletal conditions, we derived data from various smaller survey samples from defined populations. Prevalence estimates from these surveys were linked to 1990 US Bureau of the Census population data to calculate national estimates. We also estimated the expected frequency of arthritis in the year 2020. RESULTS: Current national estimates are provided, with important caveats regarding their interpretation, for self-reported arthritis and selected conditions. An estimated 15% (40 million) of Americans had some form of arthritis in 1995. By the year 2020, an estimated 18.2% (59.4 million) will be affected. CONCLUSION: Given the limitations of the data on which they are based, this report provides the best available prevalence estimates for arthritis and other rheumatic conditions overall, and for selected musculoskeletal disorders, in the US population. 相似文献
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Menselson Tamar; Rehkopf David H.; Kubzansky Laura D. 《Canadian Metallurgical Quarterly》2008,76(3):355
The authors conducted a meta-analytic review to assess the prevalence of major depressive disorder and depressive symptoms among Latinos compared with non-Latino Whites in the United States using community-based data. Random-effects estimates were calculated for 8 studies meeting inclusion criteria that reported lifetime prevalence of major depressive disorder (combined N = 76,270) and for 23 studies meeting inclusion criteria that reported current prevalence of depressive symptoms (combined N = 38,997). Findings did not indicate a group difference in lifetime prevalence of major depressive disorder (odds ratio = 0.89, 95% confidence interval = 0.72, 1.10). Latinos reported more depressive symptoms than non-Latino Whites (standardized mean difference = 0.19, 95% confidence interval = 0.12, 0.25); however, this effect was small and does not appear to suggest a clinically meaningful preponderance of depressive symptoms among Latinos. Findings are examined in the context of theories on vulnerability and resilience, and recommendations for future research are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Nine reported reasons for converting to Islam were quantitatively assessed regarding prevalence and importance among 304 women in the United States. The appeal of Muslim moral values and dissatisfaction with one’s former faith were primary reasons, followed closely by enhanced sense of identity and alignment with cultural views (regarding ethnic diversity and gender roles). Active (theological and personal) reasons for conversion were more important and prevalent than passive (social) reasons. Qualitative analyses of additional write-in responses suggested four other reasons for conversion, including the appeal of Muslim tenets and an increased sense of significance/meaning. Findings are discussed in terms of implications for future research. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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A meta-analysis of non-Hodgkin's lymphoma among farmers in the central United States 总被引:1,自引:0,他引:1
A meta-analysis of studies examining the association between non-Hodgkin's lymphoma (NHL) and employment as a farmer in the central United States was performed to verify the observation by Blair et al. [1993] that this group is at excess risk of NHL. Six studies were selected for the meta-analysis, and the estimator of relative risk calculated was 1.34 (95% confidence interval (CI) = 1.17, 1.55). Exposures associated with NHL and associated with agricultural commodities frequently produced in the central United States are infectious microorganisms and pesticides. Examination of the production patterns of the farms in this region did not reveal a single specific risk factor consistently found on all farms; however, past production patterns suggest that exposure to either infectious microorganisms or pesticides might be a risk factor for NHL in this group of farmers. 相似文献