Weanling rats, divided into 3 groups were maintained for 15 days on a diet containing either 5 per cent casein fed ad libitum (Group 1), 20 per cent casein pair-fed to Group 1 (Group 2), or 20 per cent casein fed ad libitum (Group 3). Animals were injected with either 0.9 percent saline or phenobarbital. Phenobarbital increased microsomal protein, cytochrome P-450, and phosphatidylcholine in all dietary groups; however, in all groups the increase in P-450 was greater than for phosphatidylcholine. Protein deficiency (Groups 1 vs. 2) decreased P-450 and microsomal protein but had no effect on phosphatidylcholine contents. The fraction of phosphatidylcholine-associated sites relative to the total sites was greater during protein deficiency and was in agreement with a greater Δ A_max per nmole P-450 for ethylmorphine. Phenobarbital induction decreases the proposed fraction of phosphatidylcholine-associated P-450 sites relative to the total P-450 sites and results in a decrease in the Δ A_max per nmole P-450 for ethylmorphine. Phenobarbital increased the Δ A_max per mg of microsomal protein for aniline, which paralleled the increase in total P-450 indicating that the Type II site is independent of any association Of cytochrome P-450 with phosphatidylcholine. The V_max per mg of microsomal protein was 64-66 per cent lower in the protein deficient group. Equivalent reductions of cytochrome P-450 and activities of cytochrome P-450 and c reductases were observed. Phenobarbital induction increased enzyme activities (V_max per mg of microsomal protein) in all groups with greater percentage increases in the protein deficient animals. The data suggested that phosphatidylcholine and cytochrome P-450 play important roles in the kinetics of metabolism and binding determined after protein deficiency and/or phenobarbital induction. The dietary study was repeated using 3-methylcholanthrene as inducer. 3-methylcholanthrene produced results similar to phenobarbital in most cases; however, this inducer illicits the production of a form of P-450 termed P-448. Induction of the various parameters appears more dependent on P-448 production than phosphatidylcholine-P-450 interactions. In contrast to phenobarbital treatment, 3-methylcholanthrene treatment does not increase the specific activity for ethylmorphine metabolism and the activity of cytochrome P-450 and c reductase. Other studies indicated the K_m and V_max for ethylmorphine N-demethylation is dependent on the substrate concentration range used to determine them. The oxidase system appears to have two different activities, one involving low substrate concentrations; the other, high substrate concentrations. During induction by both phenobarbital and 3-methylcholanthrene, there is a depression in both K_m and V_max during the first few hours after injection of the inducer which corresponds to the time period when the inducer is in the greatest concentration in the cell. After this initial depression, there was an increase in both K_m and V_max , indicating induction had taken place. / Ph. D.

Many lipophilic pesticides are known to be transferred to offspring via the mother's milk. The present study was conducted to determine how much endrin was transferred from endrin resistant and susceptible dams to their suckling pups and to further characterize the effects that endrin may have on the hepatic mixed function oxidase (MFO) system in the pups. Dosing of the dams with endrin began one day after birth with either (l) oral doses of endrin in corn oil or (2) a mixture of endrin in ground feed. The total amount of endrin in the pup was determined by gas chromatography. MFO activity was determined in 2-1/2 week old pups and for adult animals using maximal activities for the demethylation of ethylmorphine and hydroxylation of aniline. No difference in the amount of endrin present in the pups was observed between strains provided both received equal amounts of endrin. MFO activity for endrin dosed mature animals and for 2-1/2 week old pups from endrin dosed dams exhibited a significant decrease from control activities. There was no difference in MFO activities between age groups. A significantly higher ethylmorphine demethylase activity was observed in comparing the resistant to the susceptible strain but there was no significant difference in aniline hydroxylase activity. / Master of Science

Conclusion. The equations developed in this study provide a more accurate estimate of GFR, ranging from normal to renal impairment, in both Chinese diabetic and non-diabetic patients, compared to currently available GFR formulae. / Hypothesis/objectives. Type 2 diabetes mellitus is a major health burden associated with increased morbidity and mortality as well as socio-economic impact. A rapid increase in disease prevalence has been reported and predicted in China and other Asian countries. Patients with low and declining GFR and microalbuminuria are at high CVD risk. A simple and precise predictive equation of GFR for Chinese diabetic patients is essential in the light of the growing epidemic of diabetes and CKD in Chinese population both for monitoring and treatment purposes. In this pilot study, a set of accurate, simple and clinically practical equations to predict GFR in Chinese type 2 diabetic patients was established. Their performance was validated using separate samples of diabetic and non-diabetic subjects and compared with other widely used GFR formulae. / Methods. 202 type 2 diabetic patient and 46 non-diabetic patients were enrolled in the study. Of these 135 were randomly selected as the training sample; the remaining 67 diabetic patients and 46 non-diabetic patients constituted 2 validation groups. The prediction equation was developed by stepwise regression applied to the training sample. The equation was then tested and compared with other prediction equation including MDRD and CG equations in the validation samples. / Results. Independent factors associated with GFR included age, serum creatinine concentration, serum urea nitrogen level and serum albumin levels (P < 0.005 for all factors). Two predictive formulae, sRFCD and RFCD, were established. Simplified Renal formula in Chinese Diabetes (sRFCD) Study (ml/min/1.73 m2) is: GFR (for men) = 90400 x (Age)-0.495 (yr) x [ SCr]-1.097 (mumol/l) GFR (for women) = 58983 x (Age)-0.542 (yr) x [SCr]-1.012 (mumol/l) and Renal formula in Chinese Diabetes (RFCD) Study (ml/min/1.73 m2) is: GFR (for men) = 11825 x (Age)-0.494 x [SCr]-1.059 (mumol/l) x [Alb]+0.485 (g/l) GFR (for women) = 34166 x ( Age)-0.489 x [SCr] -0.877 (mumol/l) x [SUN] -0.150 (mmol/l) The multiple regression model explained 89.9% and 89.4% respectively of the variance in the logarithm of GFR. Compared to other GFR formulae, the sRFCD and RFCD formulae showed less bias and were more precise and accurate in estimating GFR in diabetic patients whereas the sRFCD and MDRD formulae showed better performance in non-diabetic patients. / Leung Tak Kei. / "July 2006." / Adviser: Juliana C. N. Chan. / Source: Dissertation Abstracts International, Volume: 68-08, Section: B, page: 5117. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 161-180). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Background: Platelets provide the initial haemostatic plug at sites of vascular injury. They also participate in pathological thrombosis that leads to myocardial infarction, stroke and peripheral vascular disease. The outcome of an acute myocardial infarction depends not only on the formation and stability of an occlusive thrombus, but also on the efficacy of the endogenous thrombolytic process, which allows reperfusion of the infarct related artery and prevents recurrent ischaemic episodes. Various platelet function tests are available to measure the thrombogenic potential of an individual, but the sensitivity of these tests remain questionable as most of these tests use citrated blood and measure response to a particular agonist. Endogenous thrombolysis has been a neglected entity, and its beneficial effects on cardiovascular outcomes has not been studied in depth in the past, possibly as until recently there has been no available technique to measure spontaneous thrombolytic activity in native blood. The Global Thrombosis Test (GTT) is a new point of care tests that allows us to measure time to thrombus formation (Occlusion time: OT) using native blood, avoiding the use of agonists and making the test results more physiological. The GTT also measures the time to lyse this formed thrombi without use of any lytic agents (Lysis time: LT), allowing us to measure the patient’s endogenous thrombolytic potential. Aim: Our aim in this study was to detect patients who are at risk of future thrombotic events despite dual antiplatelet therapy, either due to prothrombotic tendency or due to impaired endogenous thrombolysis, and to determine if these two parameters were correlated. Methods: GTT was used to assess the thrombotic and thrombolytic activity in healthy volunteers, and in different patient populations. 100 healthy volunteers were tested using the GTT, and a normal range was established. 300 patients admitted to hospital with a diagnosis of acute coronary syndrome (ACS) were included in the study, and tested using the GTT after they had been stabilized on dual antiplatelet therapy (Aspirin and Clopidogrel). All these patients were followed up for a year, to determine if their baseline GTT results were a predictor of recurrent cardiac events. The primary endpoint of the study was major adverse cardiovascular events (MACE), which was a composite of cardiovascular death, nonfatal myocardial infarction, or stroke at 12 months. Results: All results were analysed using statistical package SPSS version 16.0 (SPSS Inc., Chicago, Illinois). The 100 healthy volunteers were all non-smokers, and were not taking any medications. There were 55 males and 45 females, and mean age was 38±11 years (range 22-76, IQR 11). OT was normally distributed with mean OT 377.80s, and using mean ± 2SD, we derived a normal range of 185-569s (200-550s). LT demonstrated a skewed distribution with values ranging between 457 – 2934s. Using log transformation, a normal range of 592 – 1923 (600- 2000s) was established for LT. OT and LT were both prolonged in ACS patients compared to normal volunteers (p< 0.001). No association was observed between OT and risk of major adverse cardiovascular events. LT was noted to be a significant and independent predictor of MACE in a multivariate model adjusted for cardiovascular risk factors. LT ≥ 3000 s was the optimal cutoff value for predicting 6 month MACE [hazard ratio (HR): 2.48, 95% CI: 1.2-4.8, P= 0.008] and cardiovascular death [HR: 4.04, 95% CI : 1.3-12.0, P= 0.012 ] and 12 month MACE [HR:1.9, 95% CI: 1.04- 3.5,P= 0.03] and cardiovascular death [HR: 3.9,95% CI: 1.34-11.9, P= 0.013 ]. LT ≥ 3000 s was observed in 23% of ACS patients. Conclusions: Our study suggests that endogenous thrombolytic activity based on lysis of platelet rich thrombi can be assessed by the point of care GTT assay, which can help in identification of ACS patients at high risk of future cardiac events. Prolongation of OT may be explained by the antiplatelet effects of Aspirin and Clopidogrel, as both these drugs prolong time to thrombus formation and hence increase OT. Further large studies are required to study factors which can reduce thrombogenic potential, and improve endogenous thrombolytic activity, which can be monitored using the GTT to improve cardiovascular outcomes.

Background: Assessment of platelet vitality is important for patients presenting with inherited or acquired disorders of platelet function and for quality assessment of platelet concentrates. Methods: Herein we combined live stains with intra-vital confocal fluorescence microscopy in order to obtain an imaging method that allows fast and accurate assessment of platelet vitality. Three fluorescent dyes, FITC-coupled wheat germ agglutinin (WGA), tetramethylrhodamine methyl ester perchlorate (TMRM) and acetoxymethylester (Rhod-2), were used to assess platelet morphology, mitochondrial activity and intra-platelet calcium levels. Microscopy was performed with a microlens-enhanced Nipkow spinning disk-based system allowing live confocal imaging. Results: Comparison of ten samples of donor platelets collected before apheresis and platelets collected on days 5 and 7 of storage showed an increase in the percentage of Rhod-2positive platelets from 3.6 to 47 and finally to 71%. Mitochondrial potential was demonstrated in 95.4% of donor platelets and in 92.5% of platelets stored for 7 days. Conclusion: Such fast and accurate visualization of known key parameters of platelet function could be of relevance for studies addressing the quality of platelets after storage and additional manipulation, such as pathogen inactivation, as well as for the analysis of inherited platelet function disorders. / Hintergrund: Die Vitalitätsbestimmung von Blutplättchen ist sowohl für die Analyse angeborener Plättchendefekte als auch für die Qualitätsbestimmung von Plättchenkonzentraten von zentraler Bedeutung. Methoden: In der vorliegenden Arbeit stellen wir eine Methode vor, die mittels einer Kombination von Vitalfarbstoffen und konfokaler «Real time»-Mikroskopie neue Einblicke in die Vitalitätsbestimmung lebender Plättchen ermöglicht. Mittels der Zugabe von FITC-gekoppeltem Weizenkeimlektin (WGA), Tetramethylrhodamin-Methylesterperchlorat (TMRM) und Acetoxymethylester (Rhod-2) wurde bei lebenden Blutplättchen deren Morphologie, mitochondriale Aktivität und Veränderungen im Calcium-Haushalt im Rahmen der Lagerung analysiert. Für die Mikroskopie wurde ein Nipkow-System gewählt, das eine konfokale Mikroskopie lebender Zellen ermöglicht. Ergebnisse: Der Vergleich von 10 humanen Blutplättchenproben zu Beginn bzw. nach 5 und 7 Tagen Lagerung zeigte einen Anstieg der Rhod-2-positiven Plättchen von 3,6 über 47 auf 71%. Die Anzahl der Blutplättchen mit TMRM-positiven Mitochondrien hingegen lag vor der Lagerung bei 95,4% und nach den 7 Tagen Lagerung bei 92,5%. Schlussfolgerung: Die hier vorgestellte Methodik der Bildgebung zur Bestimmung vitaler Parameter von Blutplättchen eignet sich als ergänzende Analysemodalität für eine bessere Bestimmung der Blutplättchenqualität. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

The Cardiac Profile, a pattern of serum enzyme changes seen within seventy-two hours after an AMI, is diagnostic aid for detecting occurrence of infarcts. The effects of exercise stress on the Cardiac Profile aid clinicians in avoiding diagnostic errors in patients immediately after exercise. Five male volunteers ran from six to ten miles. Serum enzyme levels were monitored serially three days before and five days after stress. Enzyme activity was determined spectrophotometrically and electrophoretically. Significant increases in total CPK and LDH were seen. An LDH 'one-two flip' occurred eight hours after exercise. No MB-CPK was found following the run.

Disorders of consciousness (DoC) are a group of disorders that can occur after severe brain injury. DOC have been subdivided based on behavioural observations into: Coma, lacking any signs of wakefulness or awareness; the vegetative state, showing signs of wakefulness but lacking any signs of awareness; and the minimally conscious state, showing signs of wakefulness and infrequent and irregular signs of awareness. The so-called locked-in syndrome, a state where both wakefulness and awareness are intact, but no communication is possible due to a lack of muscle function, does not belong to the disorders of consciousness. However, it is difficult to distinguish the locked-in syndrome from DoC diagnostically, because consciousness can only be shown through consistent responses to a command and current methods for assessing consciousness rely on behavioural responses. Patients with locked-in syndrome might not be able to move voluntarily at all in the most severe cases. Behavioural assessment would then classify them as unaware. While this is an extreme and rare case, it illustrates the problem behavioural assessment poses. Such assessments are unable to distinguish the effects of impaired muscular control from impaired awareness, when either has reached an extreme level of severity. Brain damage that does not affect consciousness itself can nevertheless affect the results of the behavioural assessment of consciousness. It is then hardly surprising that the diagnosis of DoC is associated with a high level of uncertainty. The advantage of brain imaging methods is that they do not rely on the patients ability to produce a consistent behavioural response. There have therefore been efforts to use the brain imaging methods electroencephalography, positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) to aid diagnosis of disorder of consciousness. PET and fMRI have successfully been used to identify regions of difference in some patients in a DoC. Task-based fMRI has been used to identify intact consciousness, using tasks that require explicit understanding of instructions and wilful modulation of brain activity, but no motor control. One of these tasks consists of periods where the participant imagines playing tennis alternated with periods of rest. The ability to follow this paradigm is evidence of consciousness, and a few patients with a diagnosis of DoC have been shown to be able to do this task. However, the tennis task requires high order processing of the tasks requirements and the majority of patients does not respond to this task. fMRI tasks that test sensory modalities instead of consciousness have been used to show retained brain function even in DoC patients that do not respond to the tennis task. In this work the tennis task and a battery of other tasks including tactile, visual and auditory stimulation, were studied on a group of DoC patients. It was found that none of the patients responded to the task of imagining playing tennis, but retained sensory function could be identified in three out of seven patients. This highlights a strength of fMRI, namely that it can identify retained brain function below the level that is necessary for consciousness. However, the results also show that more than half of the patients studied here, did not show retained brain activation during the fMRI scan. For any of the patients that did not show a response, this can be due to an actual lack of retained brain function, but it can also be due to limitations of the task-based fMRI analysis. The fMRI tasks only test one sensory function at a time, for a short time. Thus a visual fMRI task for example, can only provide information about areas of the brain, that are involved in visual processing. And when vigilance is fluctuating, retained brain function can remain undetected, if vigilance is low during the scan. Functional connectivity analysis is a method to study internal connections between brain areas that is not dependent on an external task. It models the brain as a network of interconnected regions and studies the characteristics of this network. Graph theory is a mathematical field that has found application on many other fields using network analysis, like social sciences, metabolic network modelling or gene network modelling. In fMRI analysis, graph theory has been used to study different phenomena and pathologies and global network properties have been shown reproducibly. The work presented here aims to develop new methods based in graph theory aiding the identification of residual brain integrity. To allow an assessment of the brain network topology and its use in the assessment of residual brain integrity, a novel method was designed based on a graph theoretical measure. The method, termed Cortical Hubs And Related network Topology (CHART) is a two stage procedure. The rst stage identifies statistically significant differences in functional connectivity between two groups, using a measure of the average connectivity of each voxel, the weighted global connectivity. The second stage highlights the topology of the networks associated with those differences. Two fMRI datasets, with different underlying tasks and pathologies were used to test the CHART method. The first dataset was acquired from a group of patients with severe depression. It contrasted the state of the brain before and after successful treatment with electroconvulsive therapy. In this patient group the CHART method was able to identify an area of hyperconnectivity in the depressed state, compared to the treated state. This area of hyperconnectivity was connected to areas that had priorly been shown to be overly connected in the depressed state. The second dataset consisted of DoC patients, that had been extensively assessed behaviourally. Half of the patients were diagnosed to be in a vegetative state, the other half was diagnosed to be in a minimally conscious state. The first stage of CHART identified several areas of difference based on the weighted global connectivity. The second stage highlighted that the observed global differences were due to an overall lack of extended functional connectivity in the vegetative state patients. The addition of a healthy control group in stage two allowed comparison not only between the two DoC groups, but also with the healthy group. In summary it was observed that the spatial extent of the connectivity seen in the minimally conscious group resembles the spatial extent of the connectivity seen in the healthy control group, while the spatial extent of connectivity observed in the vegetative state group was minimal, compared to both healthy and minimally conscious group. Thus the spatial extent of connectivity is a distinguishing property for the vegetative state group studied here. However the first stage of the CHART method is a group based method. In disorders of consciousness, where the underlying pathology is different from case to case, this concept is problematic. Finding a meaningful group of interest is difficult or impossible, because lesions differ in location and extent. Individual differences in connectivity can be expected to be large, and a generalisation of the CHART result might not lead to improved diagnosis for every patient. For diagnosis, the patients individual characteristics must be taken into account. An additional objective of this work was therefore to develop a method to compare a single patient to a group of controls. An approach based on regression modelling was tested but failed to provide the necessary statistical sensitivity to detect impaired connectivity. In conclusion the CHART method developed in this work provides insights into the functional connectivity of a group of DoC patients. To assist diagnosis, further development of a method to compare a single subject to a group of controls will be important.

INTRODUÇÃO: Linfangioleiomiomatose (LAM) é uma doença rara, caracterizada pela proliferação de células musculares lisas atípicas ao redor de vias aéreas, vasos sanguíneos e linfáticos, com formação de cistos pulmonares difusos. Na prova de função pulmonar (PFP), a doença se caracteriza por padrão obstrutivo, aprisionamento aéreo e redução da capacidade de difusão do monóxido de carbono (DLCO), podendo haver resposta positiva ao teste de broncodilatação. No teste de exercício cardiopulmonar (TECP), a menor tolerância ao esforço é frequente e secundária a múltiplas causas, com maior destaque para a limitação ventilatória. Entretanto, nem todos os fatores potencialmente limitantes foram investigados. Os principais objetivos do estudo foram avaliar a prevalência e os preditores de hiperinsuflação dinâmica (HD) em pacientes com LAM, em comparação a mulheres saudáveis (controles), investigando-se adicionalmente a resposta ao broncodilatador. METODOLOGIA: Realizou-se avaliação transversal de 42 pacientes com LAM utilizando-se questionário de qualidade de vida, PFP e TECP incremental no ciclo-ergômetro, com medida seriada da capacidade inspiratória (CI) para definir HD, comparando-se aos controles. As pacientes foram ainda submetidas ao teste de caminhada de seis minutos (TC6M). A seguir, elas foram incluídas em uma avaliação randomizada, cruzada, placebocontrolada, duplo-cega (salbutamol inalatório vs. placebo). PFP e TECP com carga constante, com medida seriada da CI, foram realizadas após cada intervenção. RESULTADOS: Comparando-se aos controles, as pacientes com LAM apresentaram pior qualidade de vida, principalmente nos domínios físico e emocional, e padrão obstrutivo, aprisionamento aéreo e redução da DLCO na PFP. As pacientes demonstraram ainda menor capacidade de exercício, associada com limitação ventilatória, dispneia mais intensa e maior dessaturação no esforço. HD ocorreu em 55% das pacientes, mesmo naquelas com alteração funcional leve, e não foi observada nos controles, correlacionando-se com obstrução ao fluxo aéreo, aprisionamento aéreo, comprometimento da DLCO e dispneia. Em comparação ao subgrupo que não teve HD (subgrupo não HD), as pacientes que desenvolveram HD (subgrupo HD) tinham maior tempo de diagnóstico, caracterizando-se por obstrução ao fluxo aéreo, aprisionamento aéreo e DLCO reduzida. Apesar da capacidade de exercício semelhante, observou-se que o subgrupo HD apresentou limitação ventilatória, além de maior dessaturação e maior grau de dispneia no TECP e no TC6M. Não houve redução da HD ou aumento do tempo de exercício após utilização de salbutamol inalatório, mesmo no subgrupo HD. CONCLUSÕES: HD é frequente nas pacientes com LAM, mesmo naquelas com alteração leve na espirometria, associando-se com duração e gravidade da doença, maior grau de dispneia e menor saturação de oxigênio. Limitação ventilatória e alteração da troca gasosa são importantes fatores para interrupção do exercício em pacientes com LAM. HD também se associa com maior dessaturação e dispneia mais intensa no TC6M. Salbutamol inalatório não reduz HD ou aumenta duração do exercício no ciclo-ergômetro. / BACKGROUND: Lymphangioleiomyomatosis (LAM) is a rare disease that is characterized by the proliferation of atypical smooth muscle cells around the airways, blood vessels and lymphatics, with diffuse pulmonary cyst formation. An obstructive pattern, with air trapping, and a reduction in the diffusion capacity of the lungs for carbon monoxide (DLCO) are found in pulmonary function tests (PFTs), and there may be a positive response to the bronchodilation test. In the cardiopulmonary exercise testing (CPET), a lower exercise tolerance is frequent, secondary to multiple causes, with a greater emphasis on ventilatory limitation. However, not all potentially exercise limiting factors were evaluated. The aims of this study were to evaluate the prevalence and predictors of dynamic hyperinflation (DH) in patients with LAM in comparison with healthy women. The response to bronchodilator was also evaluated. METHODS: A cross-sectional study with 42 patients with LAM was conducted, with evaluation of a quality of life questionnaire, PFTs and a ramp CPET on cycle, with serial measurements of inspiratory capacity (IC) to establish DH. Data were compared with the healthy control subjects. The patients also performed the six-minute walk test (6MWT). Then, the patients were included in a randomized, placebo-controlled, doubleblind, crossover evaluation (inhaled salbutamol vs. placebo). After each intervention, they performed PFTs and endurance CPET with serial measurements of IC. RESULTS: In comparison with the healthy individuals, the patients with LAM experienced an impaired quality of life, mainly in the physical and emotional domains. They also had obstructive pattern, air trapping and lower DLCO in the PFTs. LAM was associated with diminished exercise performance, in association with ventilatory limitation, greater dyspnea intensity and exercise desaturation. DH occurred at a higher prevalence (55%) in patients with LAM, even in those with mild spirometric abnormalities, compared with no occurrence in the normal subjects. DH correlated with airflow obstruction, air trapping, DLCO impairment and dyspnea. The patients who developed DH (DH subgroup) had a longer duration since diagnosis and were characterized by airflow obstruction, air trapping and reduced DLCO, compared with those who did not have DH (non-DH subgroup). Although there was no difference in the exercise performance, DH subgroup had ventilatory limitation, with a higher desaturation and greater dyspnea intensity in the CPET and in the 6MWT. There was no reduction of DH or increase in exercise duration after use of inhaled salbutamol, even in the DH subgroup. CONCLUSIONS: DH is frequent in patients with LAM, even in those with mild spirometric abnormalities, and it is associated with the duration since diagnosis, the severity of disease, augmented dyspnea and lower oxygen saturation. Ventilatory limitation and gas exchange impairment are important reasons for exercise cessation in patients with LAM. DH is also associated with desaturation and greater dyspnea intensity in the 6MWT. Inhaled salbutamol does not reduce DH or improve exercise duration on cycle.

INTRODUÇÃO: A asma caracteriza-se por aumento da responsividade das vias aéreas a variados estímulos, com consequente obstrução ao fluxo aéreo, de caráter recorrente e reversível espontaneamente ou sob tratamento. A sensibilidade a alergenos é um fator de risco importante para a asma, assim como o estresse físico e emocional. Há evidências da influência psicoemotiva no desencadeamento e agravamento da doença. OBJETIVO: Avaliar a prevalência de sintomas de estresse emocional nos estudantes de curso pré-vestibular e sua possível associação com o surgimento ou agravamento dos sintomas da asma. CASUÍSTICA E MÉTODO: Uma amostra de estudantes de um curso pré-vestibular da cidade de São Paulo respondeu a um questionário sobre sintomas de asma, presença de fatores associados a asma e sintomas de estresse. Além disso, foram obtidas medidas de volume expiratório forçado no primeiro segundo e medidas do pico de fluxo expiratório.Os dados obtidos foram tratados estatisticamente. RESULTADOS: 85% dos estudantes foram classificados com escore alto de estresse emocional e 38% apresentaram sintomas de asma nos dois meses anteriores ao questionário. Há associação entre alguns sintomas de estresse (como sensação de fadiga e hipersensibilidade emocional) com sintomas de asma e parâmetros respiratórios. O teste de significância do coeficiente de Pearson mostrou correlações positivas significativas entre episódios de apatia e de sibilos nos últimos dois meses, entre sensação de fadiga e ocorrência de sibilos a qualquer tempo. Tanto a sensação de fadiga como a irritabilidade correlacionaram-se com o número de ocorrências de sibilos nesse período de dois meses. Modelos de regressão linear com significância estatística mostram ainda que entre esses indivíduos o pico de fluxo varia negativamente com o total de pontos no escore de sintomas de estresse e com o total de pontos nos fatores para asma. Além disso, encontrou-se uma alta prevalência de rinite alérgica nessa população de estudantes CONCLUSÂO: O estudo mostrou que alunos em fase pré-vestibular constituem uma população de alta prevalência de estresse emocional que se associa a sintomas de disfunção respiratória / BACKGROUND: Asthma is characterized by increased airway responsiveness to various stimuli, with consequent airflow obstruction, recurrent and reversible character spontaneously or under treatment. The sensitivity to allergens is an important risk factor for asthma, as well as the physical and emotional stress. There is evidence of psychological influence in triggering and worsening of the disease. AIMS: To assess the prevalence of emotional stress symptoms in pre-university course of students and their possible association with the emergence or worsening of asthma symptoms. METHODS: A sample of students from a pre-university course of São Paulo answered a questionnaire about symptoms of asthma, presence of factors associated with asthma and symptoms of stress. In addition, volume measurements were obtained in one second forced expiratory and measures peak flow expiratory. The data were treated statistically. RESULTS: 85% of students were classified with high scores of emotional stress and 38% showed symptoms of asthma in the two months preceding the survey. There is an association between some symptoms of stress (such as feelings of fatigue and emotional hypersensitivity) with symptoms of asthma and respiratory parameters. The significance test of Pearson\'s coefficient showed a significant positive correlation between episodes of apathy and wheezing in the past two months, between feelings of fatigue and the occurrence of wheezing at any time. Both the feeling of fatigue and irritability correlated with the number of occurrences of wheezing in that period of two months. Linear regression models with statistical significance also show that among these individuals the peak flow varies inversely with the total points on the stress symptoms score and the total score on the factors for asthma. In addition, we found a high prevalence of allergic rhinitis in this population of students CONCLUSION: The study showed that pre-university stage in students constitute a population with a high prevalence of emotional stress that is associated with symptoms of respiratory dysfunction

Wang Mei. / "July 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 208-233). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.