989 resultados para log-series distribution
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Background: Although still uncommon, pregnancy frequency in women on maintenance hemodialysis therapy has increased in the past 20 years. Most published reports suggest that intensified hemodialysis regimens result in better pregnancy outcomes. The small number of patients investigated in all reported series is the main limitation of the available studies. Study Design: Retrospective case series. Setting & Participants: Data for all pregnancies that occurred in 1988-2008 in women undergoing maintenance hemodialysis (52 pregnancies) at the Sao Paulo University Medical School (Sao Paulo, Brazil). Outcomes & Measurements: We analyzed maternal and fetal outcomes of 52 pregnancies, as well as their relationship with various clinical, laboratory, and hemodialysis parameters, such as pre-eclampsia, pregnancy before or after dialysis therapy, hemodialysis dose, polyhydramnios, anemia, and predialysis serum urea level. In addition, logistic regression models for a composite adverse fetal outcome (perinatal death or extremely premature delivery) and linear regression models for birth weight were built. Results: 87% overall rate of successful delivery, with a mean gestational age of 32.7 +/- 3.1 weeks. Pre-eclampsia was associated with a poor prognosis compared with pregnancies without pre-eclampsia: a successful delivery rate of 60% versus 92.9% (P = 0.02), extremely premature delivery rate of 77.8% versus 3.3% (P = 0.001), lower gestational age (P = 0.001), and birth weight (P = 0.001). Patients with an adverse composite fetal outcome had a higher frequency of pre-eclampsia (P = 0.001), lower frequency of polyhydramnios (P = 0.03), lower third-trimester hematocrit (P = 0.03), and higher predialysis serum urea level (P = 0.03). The same results were seen for birth weight. Limitations: Retrospective data analysis. The absence of creatinine clearance measurements did not allow evaluation of the impact of residual renal function on fetal outcome. Conclusions: Outcomes of pregnancy in women undergoing hemodialysis often are good. Preeclampsia, third-trimester hematocrit, polyhydramnios, and predialysis serum urea level are important variables associated with fetal outcome and birth weight. Am J Kidney Dis 56:77-85. (C) 2010 by the National Kidney Foundation, Inc.Inc
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Substantial experimental evidence indicates that PAWR gene (PKC apoptosis WT1 regulator; also named PAR-4, prostate apoptosis response-4) is a central player in cancer cell survival and a potential target for cancer-selective targeted therapeutics. However, little is known about the role of PAR-4 in breast cancer. We investigated the possible role of PAR-4 expression in breast cancer. IHC results on tissue microarrays containing 1,161 primary breast tumor samples showed that 57% (571/995) of analyzable cases were negative for PAR-4 nuclear staining. Down-regulation of nuclear PAR-4 protein expression predicted a poor prognosis for breast cancer patients (OS; P=0.041, log-rank test). PAR-4 down-regulation also correlates with poor survival in the group of patients with luminal A subtype breast cancer (P=0.028). Additionally, in this large series of breast cancer patients, we show that ERBB2/HER2, EGFR and pAKT protein expression are significantly associated with shorter disease-free survival and overall survival, but the prognosis was even worse for HER2-positive, EGFR-positive or pAKT-positive breast cancer patients with tumors negative for nuclear PAR-4 expression. Furthermore, using three-dimensional (3D) cell culture we provide preliminary results showing that PAR-4 is highly expressed in the MCF10A cells inside the acini structure, suggesting that PAR-4 might have a role in the lumen acini formation. Taken together, our results provide, for the first time, evidence that PAR-4 may have a role in the process of the mammary eland morphogenesis and its functional inactivation is associated with tumor aggressive phenotype and might represent an additional prognostic and predictive marker for breast cancer.
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Background: Perioperative complications following robotic-assisted radical prostatectomy (RARP) have been previously reported in recent series. Few studies, however, have used standardized systems to classify surgical complications, and that inconsistency has hampered accurate comparisons between different series or surgical approaches. Objective: To assess trends in the incidence and to classify perioperative surgical complications following RARP in 2500 consecutive patients. Design, setting, and participants: We analyzed 2500 patients who underwent RARP for treatment of clinically localized prostate cancer (PCa) from August 2002 to February 2009. Data were prospectively collected in a customized database and retrospectively analyzed. Intervention: All patients underwent RARP performed by a single surgeon. Measurements: The data were collected prospectively in a customized database. Complications were classified using the Clavien grading system. To evaluate trends regarding complications and radiologic anastomotic leaks, we compared eight groups of 300 patients each, categorized according the surgeon`s experience (number of cases). Results and limitations: Our median operative time was 90 min (interquartile range [IQR]: 75-100 min). The median estimated blood loss was 100 ml (IQR: 100-150 ml). Our conversion rate was 0.08%, comprising two procedures converted to standard laparoscopy due to robot malfunction. One hundred and forty complications were observed in 127 patients (5.08%). The following percentages of patients presented graded complications: grade 1, 2.24%; grade 2, 1.8%; grade 3a, 0.08%; grade 3b, 0.48%; grade 4a, 0.40%. There were no cases of multiple organ dysfunction or death (grades 4b and 5). There were significant decreases in the overall complication rates (p = 0.0034) and in the number of anastomotic leaks (p < 0.001) as the surgeon`s experience increased. Conclusions: RARP is a safe option for treatment of clinically localized PCa, presenting low complication rates in experienced hands. Although the robotic system provides the surgeon with enhanced vision and dexterity, proficiency is only accomplished with consistent surgical volume; complication rates demonstrated a tendency to decrease as the surgeon`s experience increased. (C) 2010 European Association of Urology. Published by Elsevier B. V. All rights reserved.
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Background. Foot deformities have been related to diabetic neuropathy progression but their influence on plantar distribution during dynamic tasks is not completely understood. The purpose of the present study was to investigate the influence of metatarsal head prominence and claw toes on regional plantar pressures during gait in patients with diabetic neuropathy Methods Seventy-one adults participated in this study categorized into three groups: a control group (CG, n = 32), patients with diabetic neuropathy without any foot deformities (DG, n = 20), and patients with diabetic neuropathy with metatarsal head prominence and/or claw toes (DMHG, n = 19). Plantar pressure variables (contact area, peak pressure, and maximum mean pressure) were evaluated during gait on rearfoot, midfoot, and forefoot using capacitive insoles (Pedar-X System, Novel Inc., Munich, Germany). A general linear model was applied to repeatedly measure and analyze variance relationships between groups and areas. Results. DMHG. presented larger contact areas at the forefoot and midfoot along with higher peak pressure at the rearfoot compared to the other two groups The DG showed higher mean pressure at the midfoot compared to:the other two groups. Conclusion. The coexistence of diabetic neuropathy and metatarsal head prominence in addition to claw toes, resulted in overloading the rearfoot and enhancing the contact area of forefoot and midfoot while walking. This plantar pressure distribution is a result of a different coordination pattern adopted in order to reduce plantar loads at the anterior parts of the foot that were structurally altered. Patients with diabetic neuropathy without any forefoot deformities presented a different plantar pressure distribution than patients with deformities suggesting that both neuropathy and structural foot alterations can influence foot rollover mechanisms.
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Oral mucosal melanoma is rare and reported to be more aggressive than its cutaneous counterpart. Due to the rarity of this entity, data on epidemiology, tumor behavior, treatment, follow-up, and Survival of patients are mainly based oil single case reports. The few existing series of patients show that oral mucosa melanoma has its peak between 4 1 and 60 years of age, and male to female ratio is 2: 1. Preferred oral sites include hard palate and maxillary alveolar crests. Risk factors have not been clearly identified, and surgical treatment is still the treatment of choice for oral mucosal melanomas. The authors retrospectively studied 35 patients with primary melanoma of the oral cavity to report their clinical and pathological features, Such as age, sex, site of the tumor, metastasis, treatment, response to therapy, and Outcome. We found no significant sex predominance, and the mean age of the patients was 60.6 years, with a range From 9 to 91 years. The majority of the patients (71.42%) had palate commitment, and invasive histopathological aspect was observed in 80% of the specimens (grade 3). Long-distance metastasis was found in 60% of the cases. Fourteen patients were submitted to wide Surgical resections, with local relapse being observed in 11 of them (78.5%). The authors Suggest that improved outcome in oral malignant melanoma requires the development of new therapies and the prevention of distant metastasis.
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Background: Organs from the so-called marginal donors have been used with a significant higher risk of primary non function than organs retrieved from the optimal donors. We investigated the early metabolic changes and blood flow redistribution in splanchnic territory in an experimental model that mimics marginal brain-dead (BD) donor. Material/Methods: Ten dogs (21.3 +/- 0.9 kg), were subjected to a brain death protocol induced by subdural balloon inflation and observed for 30 min thereafter without ally additional interventions. Mean arterial and intracranial pressures, heart rate, cardiac output (CO), portal vein and hepatic artery blood flows (PVBF and HABF, ultrasonic flowprobe), and O(2)-derived variables were evaluated. Results: An increase in arterial pressure, CO, PVBF and HABF was observed after BD induction. At the end, an intense hypotension with normalization in CO (3.0 +/- 0.2 VS. 2.8 +/- 2.8 L/min) and PVBF (687 +/- 114 vs. 623 +/- 130 ml/min) was observed, whereas HABF (277 33 vs. 134 28 ml/min, p<0.005) remained lower than baseline values. Conclusions: Despite severe hypotension induced by sudden increase of intracranial pressure, the systemic and splanchnic blood flows were partially preserved without signs of severe hypoperfusion (i.e. hyperlactatemia). Additionally, the HABF was mostly negatively affected in this model of marginal BD donor. Our data suggest that not only the cardiac output, but the intrinsic hepatic microcirculatory mechanism plays a role in the hepatic blood flow control after BD.
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Homeopathy has been used for more than two hundred years to treat chronic disease using various approaches in a wide range of diseases. However, for acute disease and critical illness, application has been limited by inadequate training of homeopathic physicians and the small number of pertinent clinical studies. In view of the difficulty of practising homeopathy in Intensive Care Units (ICU), a protocol was developed to facilitate description of objective homeopathic symptoms with a ranking of symptoms appropriate for these situations (Protocol for Objective Homeopathic Semiology). Examples of favorable results with individualized homeopathic treatments for a series of cases of Systemic Inflammatory Response Syndrome (sepsis) are described. Homeopathy (2008) 97, 206-213.
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The purpose is to present the studies of RET gene expression and acetylcholinesterase activity in 23 patients operated for Hirschsprung`s disease (HD). The patients underwent either transanal endorectal pull-through or Duhamell`s procedure. Full-thickness intestinal samples from the three different segments (ganglionic, intermediate and aganglionic) were collected. Each tissue sample was divided in two portions, one for AChE histochemical staining and the other for examination of RET mRNA expression level. All patients had an uneventful postoperative recovery. In all patients, the AChE stainings demonstrated the absence of activity in the ganglionic area, the marked increase of positive fibers in the aganglionic area, and little increase of positive fibers in the intermediate area. In the ganglionic and intermediate areas, all patients (100%) showed significant RET gene expression. In the aganglionic area, 18 patients (78.3%) did not present gene expression and the other five patients (21.7%) presented gene expression that was similar to the ganglionic and intermediate areas. The results reinforce the conclusion that the method of AChE staining is effective for the diagnosis of intestinal aganglionosis and confirm the knowledge that genes beyond RET may be implicated in the genesis of sporadic cases of HD.
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In this paper we study the possible microscopic origin of heavy-tailed probability density distributions for the price variation of financial instruments. We extend the standard log-normal process to include another random component in the so-called stochastic volatility models. We study these models under an assumption, akin to the Born-Oppenheimer approximation, in which the volatility has already relaxed to its equilibrium distribution and acts as a background to the evolution of the price process. In this approximation, we show that all models of stochastic volatility should exhibit a scaling relation in the time lag of zero-drift modified log-returns. We verify that the Dow-Jones Industrial Average index indeed follows this scaling. We then focus on two popular stochastic volatility models, the Heston and Hull-White models. In particular, we show that in the Hull-White model the resulting probability distribution of log-returns in this approximation corresponds to the Tsallis (t-Student) distribution. The Tsallis parameters are given in terms of the microscopic stochastic volatility model. Finally, we show that the log-returns for 30 years Dow Jones index data is well fitted by a Tsallis distribution, obtaining the relevant parameters. (c) 2007 Elsevier B.V. All rights reserved.
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Background Changes in the shape of the capnogram may reflect changes in lung physiology. We studied the effect of different ventilation/perfusion ratios (V/Q) induced by positive end-expiratory pressures (PEEP) and lung recruitment on phase III slope (S(III)) of volumetric capnograms. Methods Seven lung-lavaged pigs received volume control ventilation at tidal volumes of 6 ml/kg. After a lung recruitment maneuver, open-lung PEEP (OL-PEEP) was defined at 2 cmH(2)O above the PEEP at the onset of lung collapse as identified by the maximum respiratory compliance during a decremental PEEP trial. Thereafter, six distinct PEEP levels either at OL-PEEP, 4 cmH(2)O above or below this level were applied in a random order, either with or without a prior lung recruitment maneuver. Ventilation-perfusion distribution (using multiple inert gas elimination technique), hemodynamics, blood gases and volumetric capnography data were recorded at the end of each condition (minute 40). Results S(III) showed the lowest value whenever lung recruitment and OL-PEEP were jointly applied and was associated with the lowest dispersion of ventilation and perfusion (Disp(R-E)), the lowest ratio of alveolar dead space to alveolar tidal volume (VD(alv)/VT(alv)) and the lowest difference between arterial and end-tidal pCO(2) (Pa-ETCO(2)). Spearman`s rank correlations between S(III) and Disp(R-E) showed a =0.85 with 95% CI for (Fisher`s Z-transformation) of 0.74-0.91, P < 0.0001. Conclusion In this experimental model of lung injury, changes in the phase III slope of the capnograms were directly correlated with the degree of ventilation/perfusion dispersion.