900 resultados para laboratory instruments
Resumo:
The first zoeal stage of the endemic southern Atlantic pinnotherid crab Austinixa aidae is described and illustrated based on laboratory-hatched material from ovigerous females collected from the upper burrows of the thalassinidean shrimp Callichirus major at Ubatuba, So Paulo, Brazil. The zoeae of Austinixa species can be distinguished from other pinnotherids and especially from zoeae of the closely related species of Pinnixa by the telson structure.
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wPrey species show specific adaptations that allow recognition, avoidance and defense against predators. For many mammalian species this includes sensitivity towards predator-derived odors. The typical sources of such odors include predator skin and fur, urine, feces and anal gland secretions. Avoidance of predator odors has been observed in many mammalian prey species including rats, mice, voles, deer, rabbits, gophers, hedgehogs, possums and sheep. Field and laboratory studies show that predator odors have distinctive behavioral effects which include (1) inhibition of activity, (2) suppression of non-defensive behaviors such as foraging, feeding and grooming, and (3) shifts to habitats or secure locations where such odors are not present. The repellent effect of predator odors in the field may sometimes be of practical use in the protection of crops and natural resources, although not all attempts at this have been successful. The failure of some studies to obtain repellent effects with predator odors may relate to (1) mismatches between the predator odors and prey species employed, (2) strain and individual differences in sensitivity to predator odors, and (3) the use of predator odors that have low efficacy. In this regard, a small number of recent studies have suggested that skin and fur-derived predator odors may have a more profound lasting effect on prey species than those derived from urine or feces. Predator odors can have powerful effects on the endocrine system including a suppression of testosterone and increased levels of stress hormones such as corticosterone and ACTH. Inhibitory effects of predator odors on reproductive behavior have been demonstrated, and these are particularly prevalent in female rodent species. Pregnant female rodents exposed to predator odors may give birth to smaller litters while exposure to predator odors during early life can hinder normal development. Recent research is starting to uncover the neural circuitry activated by predator odors, leading to hypotheses about how such activation leads to observable effects on reproduction, foraging and feeding. (c) 2005 Elsevier Ltd. All rights reserved.
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The objectives of this cross-sectional study were to evaluate the differences between males and females in the clinical and biochemical manifestations of primary antiphospholipid antibody syndrome (PAPS). The method involved 49 patients (38 premenopausal females and 11 males) diagnosed with PAPS (according to the Sapporo criteria) and their demographic data, clinical data, medications used and antiphospholipid antibodies were analyzed. The results of this study are as follows. Both the groups of patients were statistically similar regarding age, race, weight and body mass index. However, males were significantly taller than females (172 +/- A 8.9 vs. 159.2 +/- A 6.2 cm, p < 0.0001). The duration of disease was similar for females and males. The prevalence of pulmonary thromboembolism was higher in females than in males (34.2 vs. 0.0%, p = 0.024). Regarding other PAPS manifestations (arterial events, venous events, deep venous thrombosis, thrombocytopenia, acute myocardial infarction, angina, cerebrovascular accidents and Sneddon syndrome), comorbidities (arterial hypertension and dyslipidemia), lifestyle (physical activity, previous smoking and current smoking) and the use of medications (current and previous use of corticosteroids, as well as the use of statins or chloroquine), both groups were statistically similar (p > 0.05). More females than males tested positive for IgM anticardiolipin antibodies (76.3 vs. 36.4%, p = 0.025) or for at least one of the antiphospholipid antibodies tested (either IgM anticardiolipin or IgG anticardiolipin 84.2 vs. 45.5%, p = 0.016). However, both groups were similar regarding the frequency of positivity for lupus anticoagulant and isolated IgG anticardiolipin, as well as regarding mean levels of IgG and IgM anticardiolipin (p > 0.05). We concluded that, among PAPS patients, the frequency of pulmonary thromboembolism and of positivity for IgM anticardiolipin is higher in females than in males. Our findings show that there are gender differences in PAPS, differences that might be related to alterations in sex hormones.
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A dry sand-rubber wheel abrasion test was used to investigate the wear behaviour of polyurethanes. The dry sand-rubber wheel abrasion test (DSRW test) is an approved ASTM test designed primarily for testing metals, therefore, in this study the set of test conditions was optimized for use with polyurethane elastomers. The wear performance of polyurethanes was assessed for the range of Shore hardness 85A to 65D, and a correlation was identified between the wear rate and the sample hardness. Polyurethane elastomers can be separated into three classes according to their hardness and wear performance, and each class shows a different dependence on the specimen temperature. This work has implications for use of the DSRW test for the prediction of field performance of polyurethanes. (C) Elsevier Science S.A.
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We investigated the effects of Lutzomyia longipalpis salivary glands homogenate of wild-caught and laboratory-reared vectors on the lesion evolution and immunomodulation of the infection caused by Leishmania (Leishmania) amazonensis. To compare the effect of both salivary glands homogenate (SGH), C57BL/6 mice were inoculated Subcutaneously into the hind footpads or into the ear dermis with 10(6) promastigotes in the presence or not of SGH from wild-caught and laboratory-colonized sand flies. Comparing SGH groups, the lesion size was lower in mice co-inoculated with wild-caught SGH, as the parasitism and the infiltration of macrophages at the inoculation site. Wild-caught SGH also determined lower production of IL-4 and IL-10 but higher IL-12 levels compared with laboratory-reared SGH. Our findings address a probable bias by using SGH from laboratory-colonized sand flies instead of wild-caught vector SGH in studies concerning saliva effects. A possible mild influence of sand fly saliva in natural infections caused by Leishmania is also speculated, as infection is transmitted by wild and not by laboratory-reared vectors.
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In order to compare the saliva effect from wild-caught and lab-reared L. longipalpis on the development of experimental cutaneous leishmaniasis, C57BL/6 mice were inoculated subcutaneously into the hind footpads with promastigotes of L (L.) amazonensis Plus salivary gland lysate from wild-caught (SGL-W) and lab-colonized (SGL-C) vectors. Lesion sizes were significantly larger in the mice infected with both saliva compared to mice infected with parasites alone; moreover, the lesions caused by parasite+SGL-C were significantly larger than the lesions caused by parasite+SGL-W. Histopathological morphometric studies regarding the acute phase of infections showed lower numbers of polymorphonuclear cells, greater numbers of mononuclear cells and parasites in SGL-C infected mice compared to SGL-W infected mice. In the chronic phase of infection, the number of mononuclear cells was lower and the number of parasites was greater in SGL-C infected mice than SGL-W infected mice. In vitro studies showed increased infection index of macrophages infected with parasites plus saliva compared to infection with parasites alone, with no difference between the saliva infection indices. SDS-PAGE gel for SGL-C and SGL-W showed differences in the composition and quantity of protein bands, determined by densitometry. These results call attention to the experimental saliva model, which shows exacerbation of infection caused by sandfly saliva. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
Resumo:
One of the challenges in screening for dementia in developing countries is related to performance differences due to educational and cultural factors. This study evaluated the accuracy of single screening tests as well as combined protocols including the Mini-Mental State Examination (MMSE), Verbal Fluency animal category (VF), Clock Drawing test (CDT), and Pfeffer Functional Activities Questionnaire (PFAQ) to discriminate illiterate elderly with and without Alzheimer`s disease (AD) in a clinical sample. Cross-sectional study with 66 illiterate outpatients diagnosed with mild and moderate AD and 40 illiterate normal controls. Diagnosis of AD was based on NINCDS-ADRDA. All patients were submitted to a diagnostic protocol including a clinical interview based on the CAMDEX sections. ROC curves area analyses were carried out to compare sensitivity and specificity for the cognitive tests to differentiate the two groups (each test separately and in two by two combinations). Scores for all cognitive (MMSE, CDT, VF) and functional assessments (PFAQ) were significantly different between the two groups (p < 0.001). The best screening instruments for this sample of illiterate elderly were the MMSE and the PFAQ. The cut-off scores for the MMSE, VF, CDT, and PFAQ were 17.5, 7.5, 2.5, and 11.5, respectively. The most sensitive combination came from the MMSE and PFAQ (94.1%), and the best specificity was observed with the combination of the MMSE and CDT (89%). Illiterate patients can be successfully screened for AD using well-known screening instruments, especially in combined protocols.
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Background: Tuberculous meningitis (TBM) is a growing problem in HIV-infected patients in developing countries, where there is scarce data about this co-infection. Our objectives were to analyze the main features and outcomes of HIV-infected patients with TBM. Methods: This was a retrospective study of HIV-infected Brazilian patients admitted consecutively for TBM. All patients had Mycobacterium tuberculosis isolated from the cerebrospinal fluid (CSF). Presenting clinical and laboratory features were studied. Multivariate analysis was used to identify variables associated with death during hospitalization and at 9 months after diagnosis. Survival was estimated using the Kaplan-Meier method. Results: We included 108 cases (median age 36 years, 72% male). Only 15% had fever, headache, and meningeal signs simultaneously. Forty-eight percent had extrameningeal tuberculosis. The median CD4+ cell count was 65 cells/mu l. Among 90 cases, 7% had primary resistance to isoniazid and 9% presented multidrug-resistant strains. The overall mortality during hospitalization was 29% and at 9 months was 41%. Tachycardia and prior highly active antiretroviral therapy (HAART) were associated with 9-month mortality. The 9-month survival rate was 22% (95% confidence interval 12-43%). Conclusions: Clinical and laboratory manifestations were unspecific. Disseminated tuberculosis and severe immunosuppression were common. Mortality was high and the 9-month survival rate was low. Tachycardia and prior HAART were associated with death within 9 months of diagnosis. (C) 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Resumo:
Cutaneous tuberculosis has re-emerged in the last 15 years together with the higher incidence of pulmonary tuberculosis and multidrug resistance. The choice for a single diagnostic tool among the many available today is a challenge. Our objective was to compare polymerase chain reaction (PCR) with other exams in the diagnosis of cutaneous tuberculosis and atypical mycobacteria skin infection. PCR and a set of five different exams were performed in 32 patients (34 samples of paraffin-embedded tissue) evaluated for 3 years in a university hospital, considering the response to mycobacterial infection treatment as a positive case. PCR was the most sensitive (88%) and specific (83%) exam. Culture, immunohistochemistry and acid-fast bacilli were not in agreement with clinical response to treatment. Although PCR is a useful tool, careful clinical exam is still the gold standard for the evaluation and treatment of cutaneous tuberculosis and mycobacteria skin infection.
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Goal: To describe clinical and laboratory features of human immunodeficiency infection (HIV)-infected patients with neurosyphilis. Study Design: Retrospective study of 27 consecutive cases of HIV-infected patients with a positive Venereal Disease Research Laboratory (VDRL) in cerebrospinal fluid (CSF). Results: Median of age was 36 years and 89% were men. Ten (37%) patients had previous nonneurologic syphilis treatment. At the time of neurosyphilis diagnosis, 10 (37%) patients had early syphilis, and 6 of them were neurologically asymptomatic. Nine (33%) patients had symptomatic neurosyphilis. Twenty-six (96%) patients were classified with early neurosyphilis. The medians of serum VDRL and CD4(+) T cell counts were 1:128 and 182 cell/mu L, respectively. Twenty five (93%) patients presented serum VDRL titers >= 1:16. Five of 6 patients with early syphilis and asymptomatic neurosyphilis, presented serum VDRL >= 1:16. Symptomatic patients showed lower CD4(+) T cell counts (59 cell/mu L vs. 208 cell/mu L, P = 0.03) and higher protein concentration on CSF (118 mg/dL vs. 39 mg/dL, P <0.001) than asymptomatic patients. Conclusions: Most patients had early and asymptomatic neurosyphilis, and more than one third had early syphilis. Patients with symptomatic neurosyphilis showed lower CD4(+) T cell counts and higher protein concentration on CSF than those asymptomatic. Most patients had serum VDRL titers >= 1:16, regardless of syphilis stage.
Resumo:
Background: This study was aimed at assessing the psychometric qualities of the abbreviated versions of the Alcohol Use Disorders Identification Test (AUDIT-3, AUDIT-4, AUDIT-C, AUDIT-PC, AUDIT-QF, FAST, and Five-Shot) and at comparing them to the 10-item AUDIT and the CAGE in 2 samples of Brazilian adults. Methods: The validity and internal consistency of the scales were assessed in a sample of 530 subjects attended at an emergency department and at a Psychosocial Care Center for Alcohol and Drugs. The Structured Clinical Interview for DSM-IV was used as the diagnostic comparative measure for the predictive validity assessment. The concurrent validity between the scales was analyzed by means of Pearson`s correlation coefficient. Results: The assessment of the predictive validity of the abbreviated versions showed high sensitivity (of 0.78 to 0.96) and specificity (of 0.74 to 0.94) indices, with areas under the curve as elevated as those of the AUDIT (0.89 and 0.92 to screen for abuse and 0.93 and 0.95 in the screening of dependence). The CAGE presented lower indices: 0.81 for abuse and 0.87 for dependence. The analysis of the internal consistency of the AUDIT and its versions exhibited Cronbach`s alpha coefficients between 0.83 and 0.94, while the coefficient for the CAGE was 0.78. Significant correlations were found between the 10-item AUDIT and its versions, ranging from 0.91 to 0.99. Again, the results for the CAGE were satisfactory (0.77), although inferior to the other instruments. Conclusions: The results obtained in this study confirm the validity of the abbreviated versions of the AUDIT for the screening of alcohol use disorders and show that their psychometric properties are as satisfactory as those of the 10-item AUDIT and the CAGE.
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An analyzer-based X-ray phase-contrast imaging (ABI) setup has been mounted at the Brazilian Synchrotron Light Laboratory (LNLS) for multiple imaging radiography (MIR) purposes. The algorithm employed for treating the MIR data collected at LNLS is described, and its reliability in extracting the distinct types of contrast that can be obtained with MIR is demonstrated by analyzing a test sample (thin polyamide wire). As a practical application, the possibility of studying ophthalmic tissues, corneal sequestra in this case, via MIR is investigated. (C) 2007 Elsevier B.V. All rights reserved.