194 resultados para ACTH challenge test

em Scielo Saúde Pública - SP


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The ocelot (Leopardus pardalis) is included in list of wild felid species protected by CITES and is part of conservation strategies that necessarily involve the use of assisted reproduction techniques, which requires practical and minimally invasive techniques of high reproducibility that permit the study of animal reproductive physiology. The objective of this study was to compare and validate two commercial assays: ImmuChem Double Antibody Corticosterone 125I RIA from ICN Biomedicals, Costa Mesa, CA, USA; and Coat-a-Count Cortisol 125I RIA from DPC, Los Angeles, CA, USA, for assessment of fecal glucocorticoid metabolites in ocelots submitted to ACTH (adrenocorticotropic hormone) challenge. Fecal samples were collected from five ocelots kept at the Brazilian Center of Neotropical Felines, Associação Mata Ciliar, São Paulo, Brazil, and one of the animals was chosen as a negative control. The experiment was conducted over a period of 9 days. On day 0, a total dose of 100 IU ACTH was administered intramuscularly. Immediately after collection the samples were stored at 20C in labeled plastic bags. The hormone metabolites were subsequently extracted and assayed using the two commercial kits. Previously it was performed a trial with the DPC kit to check the best extraction method for hormones metabolites. Data were analyzed with the SAS program for Windows V8 and reported as means ± SEM. The Schwarzenberger extraction method was slightly better when compared with the Wasser extraction method (103,334.56 ± 19,010.37ng/g of wet feces and 59,223.61 ± 12,725.36ng/g of wet feces respectively; P=0,0657). The ICN kit detected an increase in glucocorticoid metabolite concentrations in a more reliable manner. Metabolite concentrations (ng/g wet feces) on day 0 and day 1 were 66,956.28 ± 36,786.93 and 92,991.19 ± 28,555.63 for the DPC kit, and 205,483.32 ± 83,811.32 and 814,578.75 ± 292,150.47 for the ICN kit, respectively. The limit of detection for the ICN kit was 7.7 ng/mL for 100% B/Bo (25ng/mL for 88%B/Bo) and for the DPC kit it was 0.2ug/dL for 90.95% B/Bo (1ug/dL for 81.27% B/Bo). In conclusion it was confirmed that the Schwarzenberger extraction method and the ICN kit are superior for extracting and measuring fecal glucocorticoid metabolites in ocelot fecal samples.

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The aim of the present study was to verify the sensitivity to the carbon dioxide (CO2) challenge test of panic disorder (PD) patients with respiratory and nonrespiratory subtypes of the disorder. Our hypothesis is that the respiratory subtype is more sensitive to 35% CO2. Twenty-seven PD subjects with or without agoraphobia were classified into respiratory and nonrespiratory subtypes on the basis of the presence of respiratory symptoms during their panic attacks. The tests were carried out in a double-blind manner using two mixtures: 1) 35% CO2 and 65% O2, and 2) 100% atmospheric compressed air, 20 min apart. The tests were repeated after 2 weeks during which the participants in the study did not receive any psychotropic drugs. At least 15 of 16 (93.7%) respiratory PD subtype patients and 5 of 11 (43.4%) nonrespiratory PD patients had a panic attack during one of two CO2 challenges (P = 0.009, Fisher exact test). Respiratory PD subtype patients were more sensitive to the CO2 challenge test. There was agreement between the severity of PD measured by the Clinical Global Impression (CGI) Scale and the subtype of PD. Higher CGI scores in the respiratory PD subtype could reflect a greater sensitivity to the CO2 challenge due to a greater severity of PD. Carbon dioxide challenges in PD may define PD subtypes and their underlying mechanisms.

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Inhalation of hypertonic saline (HS) causes bronchoconstriction in asthmatic subjects. Repeated inhalation of HS leads to substantially reduced bronchoconstriction, known as the refractory period. Refractoriness due to different stimuli has also been described (cross-refractoriness). Nocturnal asthma is defined as an increase in symptoms, need for medication, airway responsiveness, and/or worsening of lung function that usually occurs from 4 to 6 am. Our objective was to determine the effect of refractoriness on nocturnal asthma. The challenge test consisted of inhalations of 4.5% saline with increasing durations until a reduction of 20% in forced expiratory volume in 1 s (FEV1) (PD20HS) or total time of 15.5 min. Twelve subjects with nocturnal asthma were challenged with HS at 16:00 and 18:00 h and FEV1 was measured at 4:00 h. One to 2 weeks later, FEV1 was determined at 16:00 and 4:00 h. LogPD20HS at 18:00 h was significantly greater than logPD20HS at 16:00 h, 0.51 ± 0.50 and 0.69 ± 0.60 mg, respectively (P = 0.0033). When subjects underwent two HS challenges in the afternoon, mean (± SD) FEV1 reduction was 206 ± 414 mL or 9.81 ± 17.42%. On the control day (without challenge in the afternoon) FEV1 reduction was 523 ± 308 mL or 22.75 ± 15.40% (P = 0.021). Baseline FEV1 values did not differ significantly between the control and study days, 2.48 ± 0.62 and 2.36 ± 0.46 L, respectively. The refractory period following HS challenges reduces the nocturnal worsening of asthma. This new concept may provide beneficial applications to asthmatic patients.

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Analysis of faecal glucocorticoid metabolites provides a powerful noninvasive tool for monitoring adrenocortical activity in wild animals. However, differences regarding the metabolism and excretion of these substances make a validation for each species and sex investigated obligatory. Although maned wolves (Chrysocyon brachyurus) are the biggest canids in South America, their behaviour and physiology are poorly known and they are at risk in the wild. Two methods for measuring glucocorticoid metabolites in maned wolves were validated: a radio- and an enzyme immunoassay. An ACTH challenge was used to demonstrate that changes in adrenal function are reflected in faecal glucocorticoid metabolites. Our results suggest that both methods enable a reliable assessment of stress hormones in maned wolves avoiding short-term rises in glucocorticoid concentrations due to handling and restraint. These methods can be used as a valuable tool in studies of stress and conservation in this wild species.

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Our aim was to observe the induction of panic attacks by a hyperventilation challenge test in panic disorder patients (DSM-IV) and their healthy first-degree relatives. We randomly selected 25 panic disorder patients, 31 healthy first-degree relatives of probands with panic disorder and 26 normal volunteers with no family history of panic disorder. All patients had no psychotropic drugs for at least one week. They were induced to hyperventilate (30 breaths/min) for 4 min and anxiety scales were applied before and after the test. A total of 44.0% (N = 11) panic disorder patients, 16.1% (N = 5) of first-degree relatives and 11.5% (N = 3) of control subjects had a panic attack after hyperventilating (chi² = 8.93, d.f. = 2, P = 0.011). In this challenge test the panic disorder patients were more sensitive to hyperventilation than first-degree relatives and normal volunteers. Although the hyperventilation test has a low sensitivity, our data suggest that there is no association between a family history of panic disorder and hyperreactivity to an acute hyperventilation challenge test. Perhaps cognitive variables should be considered to play a specific role in this association since symptoms of a panic attack and acute hyperventilation overlap.

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Our aim was to compare the clinical features of panic disorder (PD) patients sensitive to hyperventilation or breath-holding methods of inducing panic attacks. Eighty-five PD patients were submitted to both a hyperventilation challenge test and a breath-holding test. They were asked to hyperventilate (30 breaths/min) for 4 min and a week later to hold their breath for as long as possible, four times with a 2-min interval. Anxiety scales were applied before and after the tests. We selected the patients who responded with a panic attack to just one of the tests, i.e., those who had a panic attack after hyperventilating (HPA, N = 24, 16 females, 8 males, mean age ± SD = 38.5 ± 12.7 years) and those who had a panic attack after breath holding (BHPA, N = 20, 11 females, 9 males, mean age ± SD = 42.1 ± 10.6 years). Both groups had similar (chi² = 1.28, d.f. = 1, P = 0.672) respiratory symptoms (fear of dying, chest/pain disconfort, shortness of breath, paresthesias, and feelings of choking) during a panic attack. The criteria of Briggs et al. [British Journal of Psychiatry, 1993; 163: 201-209] for respiratory PD subtype were fulfilled by 18 (75.0%) HPA patients and by 14 (70.0%) BHPA patients. The HPA group had a later onset of the disease compared to BHPA patients (37.9 ± 11.0 vs 21.3 ± 12.9 years old, Mann-Whitney, P < 0.001), and had a higher family prevalence of PD (70.8 vs 25.0%, chi² = 19.65, d.f. = 1, P = 0.041). Our data suggest that these two groups - HPA and BHPA patients - may be specific subtypes of PD.

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With the aim of investigating the presence of latent inflammatory process in the lungs of patients with Crohn's disease, 15 patients with Crohn's disease were evaluated by spirometry, the methacholine challenge test, induced sputum, and skin tests for inhaled antigens. Serum IgE, erythrocyte sedimentation rate and hematocrit were also determined. The patients were compared with 20 healthy controls by the Mann-Whitney and Fisher exact tests. Their respiratory physical examination was normal. None had a personal or family history of clinical atopy. None had a previous history of pulmonary disease, smoking or toxic bronchopulmonary exposure. None had sinusitis, migraine, diabetes mellitus, or cardiac failure. Four (26.6%) of the patients with Crohn's disease had a positive methacholine challenge test whereas none of the 20 controls had a positive methacholine test (P = 0.026, Fisher exact test). Patients with Crohn's disease had a higher level of lymphocytes in induced sputum than controls (mean 14.59%, range 3.2-50 vs 5.46%, 0-26.92%, respectively; P = 0.011, Mann-Whitney test). Patients with Crohn's disease and a positive methacholine challenge test had an even higher percentage of lymphocytes in induced sputum compared with patients with Crohn's disease and a negative methacholine test (mean 24.88%, range 12.87-50 vs 10.48%, 3.2-21.69%; P = 0.047, Mann-Whitney test). The simultaneous findings of bronchopulmonary lymphocytosis and bronchial hyperresponsiveness in patients with Crohn's disease were not reported up to now. These results suggest that patients with Crohn's disease present a subclinical inflammatory process despite the absence of pulmonary symptoms.

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The objective of the present study was to investigate the effects of the direct addition of pentoxifylline (PF) to the ejaculates of men with poor sperm quality before freezing on post-thaw sperm motility, viability, acrosome integrity, and agonist-induced acrosome reaction. Semen specimens from 16 infertile men with impaired sperm count and motility (oligoasthenozoospermia) were divided into two equal aliquots: one received no treatment (control) while the other was incubated with 5 mM PF (treated). Both aliquots were cryopreserved by the liquid nitrogen vapor method. Motility was assessed according to WHO criteria. Acrosome integrity and spontaneous and calcium ionophore-induced acrosome reactions were assessed with fluorescein isothiocyanate-conjugated peanut agglutinin combined with a supra-vital dye (Hoechst-33258). Cryopreservation impaired sperm motility (percentage reduction: 87.4 (interquartile range, IQ: 70.3-92.9) vs 89.1 (IQ: 72.7-96.0%)), viability (25.9 (IQ: 22.2-29.7) vs 25.6 (IQ: 19.7-40.3%)) and acrosome integrity (18.9 (IQ: 5.4-38.9) vs 26.8 (IQ: 0.0-45.2%)) to the same extent in both treated and control aliquots. However, PF treatment before freezing improved the acrosome reaction to ionophore challenge test scores in cryopreserved spermatozoa (9.7 (IQ: 6.6-19.7) vs 4.8 (IQ: 0.5-6.8%); P = 0.002). These data show that pre-freeze treatment of poor quality human sperm with pentoxifylline did not improve post-thaw motility or viability nor did it prevent acrosomal loss during the freeze-thaw process. However, PF, as used, improved the ability of thawed spermatozoa to undergo the acrosome reaction in response to calcium ionophore. The present data indicate that treatment of poor quality human sperm with PF may enhance post-thaw sperm fertilizing ability.

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We detected Toxoplasma gondii oocysts in feces of experimentally infected cats, using a Kato Katz approach with subsequent Kinyoun staining. Animals serologically negative to T. gondii were infected orally with 5x10² mice brain cysts of ME49 strain. Feces were collected daily from the 3rd to the 30th day after challenge. Oocysts were detected by qualitative sugar flotation and the quantitative modified Kato Katz stained by Kinyoun (KKK). In the experimentally infected cats, oocysts were detected from the 7th to 15th day through sugar flotation technique, but oocysts were found in KKK from the 6th to 16th day, being sensitive for a larger period, with permanent documentation. The peak of oocysts excretion occurred between the 8th to 11th days after challenge, before any serological positive result. KKK could be used in the screening and quantification of oocysts excretion in feces of suspected animals, with reduced handling of infective material, decreasing the possibility of environmental and operator contamination.

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It is widely accepted that the classical constant-temperature hot-plate test is insensitive to cyclooxygenase inhibitors. In the current study, we developed a variant of the hot-plate test procedure (modified hot-plate (MHP) test) to measure inflammatory nociception in freely moving rats and mice. Following left and right hind paw stimulation with a phlogogen and vehicle, respectively, the animals were placed individually on a hot-plate surface at 51ºC and the withdrawal latency for each paw was determined simultaneously in measurements performed at 15, 60, 180, and 360 min post-challenge. Plantar stimulation of rats (250 and 500 µg/paw) and mice (125-500 µg/paw) with carrageenan led to a rapid hyperalgesic response of the ipsilateral paw that reached a plateau from 15 to 360 min after challenge. Pretreatment with indomethacin (4 mg/kg, ip) inhibited the phenomenon at all the times analyzed. Similarly, plantar stimulation of rats and mice with prostaglandin E2 (0.5 and 1 µg/paw) also resulted in rapid hyperalgesia which was first detected 15 min post-challenge. Finally, we observed that the MHP test was more sensitive than the classical Hargreaves' test, being able to detect about 4- and 10-fold lower doses of prostaglandin E2 and carrageenan, respectively. In conclusion, the MHP test is a simple and sensitive method for detecting peripheral hyperalgesia and analgesia in rats and mice. This test represents a low-cost alternative for the study of inflammatory pain in freely moving animals.

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Abstract This article presents the increasing demands over the Brazilian Ministry of Foreign Affairs (Itamaraty) for opening its doors to other actors. This discussion will be followed by relevant theoretical and methodological analysis. We will defend the need to overcome problems related to: 1) conceptual vagueness about what the concept of participation means; 2) lack of clarity in the baseline to which comparisons are made; 3) fragile empirical basis; 4) limitations on the use of sources; and 5) how to understand the impact exerted by systemic forces.

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Foi aplicada uma versão reduzida do "Face-Hand Test", o FHT-R, em 91 pessoas com 65 anos ou mais em uma amostra ao acaso de idosos vivendo na comunidade (São Paulo, Brasil), com objetivo de testar a habilidade do instrumento em detectar as síndromes psicorgânicas. Os escores do FHT-R foram comparados com as avaliações de um psiquiatra utilizando uma entrevista semi-estruturada, a "Clinical Interview Schedule". Cinco pessoas foram consideradas como sendo portadoras de distúrbios psicorgânicos e 86 como não sendo portadoras de tais distúrbios. No ponto de corte 0/1 os coeficientes de validação obtidos foram: sensibilidade 60%, especificidade 94%, valor prognóstico positivo 38%, valor prognóstico negativo 98%, e taxa de classificação incorreta 8%. A utilização do Teste em pesquisas epidemiológicas é discutida no corpo do trabalho.

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The study was carried out to evaluate the diagnostic performance of the ICT malaria Pf/PvTM test for vivax malaria diagnosis in Belém, Amazon region, Brazil. The results of blood malaria parasites examination using an immunochromatography test were compared with thick blood film (TBF) examination. It was also evaluated the performance of this test storaged at three different temperatures (25°C, 30°C, and 37°C) for 24 hours before use. Overall sensitivity of ICT Pf/PvTM was 61.8% with a specificity of 100%, positive and negative predictive value of 100% and 71.8%, respectively and accuracy of 80.6%. The test sensitivity was independent of the parasite density. This test needs to be further reviewed in order to have better performance for P. vivax malaria diagnosis.

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OBJECTIVE: To analyze the scoring obtained by an instrument, which evaluates the ability to read and understand items in the health care setting, according to education and age. METHODS: The short version of the Test of Functional Health Literacy in Adults was administered to 312 healthy participants of different ages and years of schooling. The study was conducted between 2006 and 2007, in the city of São Paulo, Southeastern Brazil. The test includes actual materials such as pill bottles and appointment slips and measures reading comprehension, assessing the ability to read and correctly pronounce a list of words and understand both prose passages and numerical information. Pearson partial correlations and a multiple regression model were used to verify the association between its scores and education and age. RESULTS: The mean age of the sample was 47.3 years(sd=16.8) and the mean education was 9.7 years(sd=5; range: 1 - 17). A total of 32.4% of the sample showed literacy/numeracy deficits, scoring in the inadequate and marginal functional health literacy ranges. Among the elderly (65 years or older) this rate increased to 51.6%. There was a positive correlation between schooling and scores (r=0.74; p<0.01) and a negative correlation between age and the scores (r=-0.259; p<0.01). The correlation between the scores and age was not significant when the effects of education were held constant (rp=-0.031, p=0.584). A significant association (B=3.877, Beta =0.733; p<0.001) was found between schooling and scores. Age was not a significant predictor in this model (B=-0.035, Beta=-0.22; p=0.584). CONCLUSIONS: The short version of the Test of Functional Health Literacy in Adults was a suitable tool to assess health literacy in the study population. The high number of individuals classified as functional illiterates in this test highlights the importance of special assistance to help them properly understand directions for healthcare.