The ability to discriminate between normal and impaired dynamic cerebral autoregulation (CA), based on measurements of spontaneous fluctuations in arterial blood pressure (BP) and cerebral blood flow (CBF), has considerable clinical relevance. We studied 45 normal subjects at rest and under hypercapnia induced by breathing a mixture of carbon dioxide and air. Non-linear models with BP as input and CBF velocity (CBFV) as output, were implemented with support vector machines (SVM) using separate recordings for learning and validation. Dynamic SVM implementations used either moving average or autoregressive structures. The efficiency of dynamic CA was estimated from the model’s derived CBFV response to a step change in BP as an autoregulation index for both linear and non-linear models. Non-linear models with recurrences (autoregressive) showed the best results, with CA indexes of 5.9 ± 1.5 in normocapnia, and 2.5 ± 1.2 for hypercapnia with an area under the receiver-operator curve of 0.955. The high performance achieved by non-linear SVM models to detect deterioration of dynamic CA should encourage further assessment of its applicability to clinical conditions where CA might be impaired.

Panic patients have decreased heart rate variability, a risk factor for sudden cardiac death, and increased rates of cardiac death and stroke. Imipramine has been found to further reduce heart rate variability in panic. This study uses power spectral analysis to compare autonomic components of heart rate variability in 16 unmedicated control subjects and 17 panic patients before and after treatment with paroxetine at 20 mg/day for 4 weeks. Patients had higher predrug reclining and standing sympathetic activity than control subjects. After drug, patients' total sympathetic activity decreased. Predrug patients failed to increase sympathetic activity on orthostasis, lacking the normal baroreflex response found in control subjects. After drug, patients normalized this sympathetic component of the baroreflex response. Before drug, patients' parasympathetic reclining and standing activity did not differ from control subjects, and patients showed the normal orthostatic parasympathetic decrease. After drug, patients' total parasympathetic activity increased, whereas the baroreflex response was preserved. Nine medicated patients had more than a 50% reduction of panic attacks. In view of paroxetine's increase of heart rate variability, potential benefits of selective serotonin reuptake inhibitors in decreasing cardiac mortality in panic disorder are discussed.

These data showed that ovarian hormones deprivation induced marked changes on cardiovascular control, increasing SAP variability and cardiac sympatho-vagal balance and blunting BRS in female hypertensive animals, which reinforce the possible protective role of ovarian hormones on the cardiovascular system.

Comparação da resposta autônomica cardiovascular IntroduçãoComparação da resposta autonômica cardiovascular de praticantes de musculação, corredores de longa distância e não praticantes de exercício CDD. 20.ed. 796.022 796.073

Aims and background: Cells and soluble mediators obtained from tumor effusions are useful in evaluating the tumor microenvironment. Our aim was to examine cytologicelly and to quantify the leukocyte infiltrate, nitric oxide, cytokines and tumor markers in the intracystic fluid from patients with a cystic adnexal mass, for a possible differentiation between benign and malignant findings. Methods and study design: Sixty-six women who had their cystic fluids collected were prospectively divided into benign tumor (22, 33.3%), malignant tumor (10, 15.2%) or other gynecological alterations (34, 51.5%). Cytology, total and differential leukocyte counts were determined by light microscopy. Tumor markers, cytokines and nitric oxide were assayed in the supernatants using the lmmulite system, ELISA and Griess reaction, respectively. Results: The sensitivity and specificity of the cytological analysis was 66.7% and 97.7%, respectively. The levels of CA 19.9, CA 15.3, a-fetoprotein, carcinoembryonic antigen, progesterone and 13-HCG were significantly higher in the benign and/or malignant group than in the other gynecological alterations. Also, the local concentrations of CA 15.3 and 13-HCG were significantly higher in malignant than in benign tumors. In malignant tumors, increased leukocyte counts and higher concentrations of IL-6, IL-10 and nitric oxide were detected than in benign tumors or other gynecological alterations. Conclusions: In malignant tumors, the microenvironment could be differentiated from benign tumors or other gynecological alterations by cystic fluid analysis.