990 resultados para Proportion.


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BACKGROUND: The development of newer diagnostic technologies has reduced the need for invasive electroencephalographic (EEG) studies in identifying the epileptogenic zone, especially in adult patients with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS). OBJECTIVE: To evaluate ictal single photon emission computed tomography (SPECT) in the evaluation and treatment of patients with MTLE-HS. METHODS: MTLE patients were randomly assigned to those with (SPECT, n = 124) and without ictal SPECT (non-SPECT, n = 116) in an intent-to-treat protocol. Primary end points were the proportion of patients with invasive EEG studies, and those offered surgery. Secondary end points were the length of hospital stay and the proportion of patients with secondarily generalized seizures (SGS) during video-EEG, postsurgical seizure outcome, and hospital cost. RESULTS: The proportion of patients offered surgery was similar in the SPECT (85%) and non-SPECT groups (81%), as well as the proportion that had invasive EEG studies (27% vs 23%). The mean duration of hospital stay was 1 day longer for the SPECT group (P < 0.001). SGS occurred in 51% of the SPECT and 26% of the non-SPECT group (P < 0.001). The cost of the presurgical evaluation was 35% higher for the SPECT compared with the non-SPECT group (P < 0.001). The proportion of patients seizure-free after surgery was similar in the SPECT (59%) compared with non-SPECT group (54%). CONCLUSION: Ictal-SPECT did not add localizing value beyond what was provided by EEG-video telemetry and structural MRI that altered the surgical decision and outcome for MTLE-HS patients. Ictal-SPECT increased hospital stay was associated with increased costs and a higher chance of SGS during video-EEG monitoring. These findings support the notion that a protocol including ictal SPECT is equivalent to one without SPECT in the presurgical evaluation of adult patients with MTLE-HS.

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In this study, a PCR multiplex was optimized, allowing the simultaneous analysis of 13 X-chromosome Insertion/deletion polymorphisms (INDELs). Genetic variation observed in Africans, Europeans, and Native Americans reveals high inter-population variability. The estimated proportions of X-chromosomes in an admixed population from the Brazilian Amazon region show a predominant Amerindian contribution (congruent to 41%), followed by European (congruent to 32%) and African (congruent to 27%) contributions. The proportion of Amerindian contribution based on X-linked data is similar to the expected value based on mtDNA and Y-chromosome information. The accuracy for assessing interethnic admixture, and the high differentiation between African, European, and Native American populations, demonstrates the suitability of this INDEL set to measure ancestry proportions in three-hybrid populations, as it is the case of Latin American populations. Am. J. Hum. Biol. 21:707-709, 2009. (C) 2009 Wiley-Liss, Inc.

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Leukostasis is a relatively uncommon but potentially catastrophic complication of acute myelogenous leukemia (AML). Prompt leukoreduction is considered imperative to reduce the high mortality rate in this condition. Leukapheresis, usually associated with chemotherapy, is an established approach to diminish blast cell counts. We report a single center experience in managing leukostasis with leukapheresis. Fifteen patients with leukostasis of 187 patients with AML (8.02%) followed at our institution were treated with leukapheresis associated with chemotherapy. The procedures were scheduled to be performed on a daily basis until clinical improvement was achieved and WBC counts were significantly reduced. Overall and early mortalities, defined as that occurred in the first 7 days from diagnosis, were reported. A high proportion of our patients with leukostasis (46.66%) had a monocytic subtype AML (M4/M5, according to French-American-British classification). The median overall survival was 10 days, despite a significant WBC reduction after the first apheresis procedure (from 200.7 X 10(9)/L to 150.3 X 10(9)/L). Almost half of patients (7/15) had an early death. Therapeutic leukapheresis, associated or not to chemotherapy, is an effective approach to reduce WBC counts in patients with AML and leukostasis; however, this therapeutic procedure does not appear to change significantly the sombre prognosis observed in the majority of patients with this complication. Other forms of treatment must be found to reduce the high mortality rate related to leukostasis. J. Clin. Apheresis 26:181-185, 2011. (C) 2011 Wiley-Liss, Inc.

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center dot Citalopram (CITA) pharmacokinetics are enantioselective in healthy volunteers and the metabolism of (+)-(S)-CITA to (+)-(S)-DCITA is dependent on CYP2C19. Omeprazole is a potent CYP2C19 inhibitor. WHAT THIS STUDY ADDS center dot This study indicates that omeprazole induces a loss of enantioselectivity in the CITA pharmacokinetics because of the selective inhibition of (+)-(S)-CITA metabolism. AIM The study assessed the influence of omeprazole on the kinetic disposition of the (+)-(S)-citalopram (CITA) and (-)-(R)-CITA enantiomers in healthy volunteers. METHODS In a cross-over study, healthy volunteers (n = 9) phenotyped as extensive metabolizers of CYP2C19 and CYP2D6 and with an oral midazolam clearance ranging from 10.9 to 149.3 ml min-1 kg-1 received a single dose of racemic CITA (20 mg orally) in combination or not with omeprazole (20 mg day-1 for 18 days). Serial blood samples were collected up to 240 h after CITA administration. CITA and demethylcitalopram (DCITA) enantiomers were analyzed by LC-MS/MS using a Chiralcel (R) OD-R column. RESULTS The kinetic disposition of CITA was enantioselective in the absence of treatment with omeprazole, with the observation of a greater proportion of plasma (-)-(R)-CITA [AUC S : R ratio of 0.53 (95% CI 0.41, 0.66) for CITA and 1.08 (95% CI 0.80, 1.76) for DCITA] than (+)-(S)-CITA. Racemic CITA administration to healthy volunteers in combination with omeprazole showed a loss of enantioselectivity in CITA pharmacokinetics with an increase of approximately 120% in plasma (+)-(S)-CITA concentrations [AUC S : R ratio of 0.95 (95% CI 0.72, 1.10) for CITA and 0.95 (95% CI 0.44, 1.72) for DCITA]. CONCLUSIONS The administration of multiple doses of omeprazole preferentially inhibited (+)-(S)-CITA metabolism in healthy volunteers. Although omeprazole increased plasma concentrations of (+)-(S)-CITA by approximately 120%, it is difficult to evaluate the clinical outcome because the range of plasma CITA concentrations related to maximum efficacy and minimum risk of adverse effects has not been established.

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Estimating the proportions of different ancestries in admixed populations is very important in population genetics studies, and it is particularly important for detecting population substructure effects in case-control association studies. In this work, a set of 48 ancestry, informative insertion, deletion polymorphisms (INDELs) were selected with the goal of efficiently measuring the proportions of three different ancestries (sub-Saharan African, European, and Native American) in mixed populations. All selected markers can be easily analyzed via multiplex PCR and detected with standard capillary electrophoresis. A total of 593 unrelated individuals representative of European, African, and Native American parental populations were typed, as were 380 individuals from three Brazilian populations with known admixture patterns. As expected, the interethnic admixture estimates show that individuals from southern Brazil present an almost exclusively European ancestry; Afro-descendant communities in the Amazon region, apart from the major African contribution, present some degree of admixture with Europeans and Native Americans; and a sample from Belem, in the northeastern Amazon, shows a significant contribution of the three ethnic groups, although with a greater European proportion. In summary, a panel of ancestry-informative INDELs was optimized and proven to be a variable tool for estimating individual and global ancestry proportions in admixed populations. The ability to accurately infer interethnic admixtures highlights the usefulness of this marker set for assessing population substructure in association studies, particularly those conducted in Brazilian and other Latin American populations sharing trihybrid ancestry patterns. Hum Mutat 31:184-190, 2010. (C) 2009 Wiley-Liss, Inc.

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Background: Making the diagnosis of acute pulmonary thromboembolism (APT) and assessing its severity is very challenging, While cardiac troponin I (cTnI) concentrations are promising in risk stratification, no previous study has examined whether there is a linear relation between cTnI concentrations and the severity of APT. Moreover, matrix metalloprotemases (MMPs) are involved in the pathophysiology of APT. However, it is unknown whether the increases in MMP concentrations after APT reflect the severity of this condition. We examined whether the circulating concentrations of these biomarkers increase in proportion to the severity of experimental APT induced in anesthetized dogs. Methods: APT was induced with autologous blood clots (saline, 1, 3, or 5 ml/kg) injected into the right atrium. Hemodynamic evaluations were carried out for 120 min. Gelatin zymography of MMP-2 and MMP-9 from plasma samples were performed and serum cTnI concentrations were determined at baseline and 120 min after APT. Results: While no significant increases in pro-MMP-2 concentrations were found after APT, pro-MMP-9 concentrations increased by 80% only after 5 ml/kg of clot embolization. Serum cTnI and plasma pro-MMP-9 concentrations correlated positively with pulmonary vascular resistance (P=0.007 and rs=0.833 for troponin 1, and P=0.034 and rs=0.684 for pro-MMP-9) and with pulmonary artery pressure (P=0.005 and rs=0.610 for troponin 1, and P=0.022 and rs=0.720 for pro-MMP-9). Conclusions: Circulating cTnI and pro-MMP-9 increase in proportion to the severity of APT, although the increases in plasma pro-MMP-9 are less clear with less severe APT. These findings may be relevant for clinical APT. (C) 2007 Elsevier B.V. All rights reserved.

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Successful reproduction requires that changes in plasma follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), oxytocin (OT), estrogen (E-2) and progesterone (P-4) occur together with the display of maternal behaviors. Ovarian steroids and environmental stimuli can affect the dendritic spines in the rat hippocampus. Here, studying Wistar rats, it is described: (a) the sequential and concomitant changes in the hormonal profile of females at postpartum days (PP) 4, 8, 12, 16, 20 and 24, comparing to estrous cycle referential values; (b) the dendritic spine density in the stratum radiatum of CA1 (CA1-SR) Golgi-impregnated neurons in virgin females across the estrous cycle and in multiparous age-matched ones; and (c) the proportion of different types of spines in the CAI-SR of virgin and postpartum females, both in diestrus. Plasma levels of gonadotrophins and ovarian hormones remained low along PP while LH increased and PRL decreased near the end of the lactating period. The lowest dendritic spine density was found in virgin females in estrus when compared to diestrus and proestrus phases or to postpartum females in diestrus (p < 0.03). Other comparisons among groups were not statistically significant (p > 0.4). There were no differences in the proportions of the different spine types in nulliparous and postpartum females (p > 0.2). Results suggest that medium layer CA1-SR spines undergo rapid modifications in Wistar females across the estrous cycle (not quite comparable to Sprague-Dawley data or to hormonal substitutive therapy following ovariectomy), but persistent effects of motherhood on dendritic spine density and morphology were not found in this area. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

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The spread of an infectious disease in a population involves interactions leading to an epidemic outbreak through a network of contacts. Extending on Watts and Strogatz (1998) who showed that short-distance connections create a small-world effect, a model combining short-and long-distance probabilistic and regularly updated contacts helps considering spatial heterogeneity. The method is based on cellular automata. The presence of long-distance connections accelerates the small-world effect, as if the world shrank in proportion of their total number.

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Historically, the cure rate model has been used for modeling time-to-event data within which a significant proportion of patients are assumed to be cured of illnesses, including breast cancer, non-Hodgkin lymphoma, leukemia, prostate cancer, melanoma, and head and neck cancer. Perhaps the most popular type of cure rate model is the mixture model introduced by Berkson and Gage [1]. In this model, it is assumed that a certain proportion of the patients are cured, in the sense that they do not present the event of interest during a long period of time and can found to be immune to the cause of failure under study. In this paper, we propose a general hazard model which accommodates comprehensive families of cure rate models as particular cases, including the model proposed by Berkson and Gage. The maximum-likelihood-estimation procedure is discussed. A simulation study analyzes the coverage probabilities of the asymptotic confidence intervals for the parameters. A real data set on children exposed to HIV by vertical transmission illustrates the methodology.

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Background: Women are especially vulnerable to HIV infection because of biological, social, cultural, and economic factors. In Brazil, AIDS was initially seen predominantly in homosexual men, but the epidemic gradually reached a gender balance as increasing numbers of women became infected with HIV. Objective: The aim of the present study was to identify the clinical and epidemiologic characteristics of hospitalized patients with HIV/AIDS of both sexes and compare the differences between them. Methods: This epidemiologic cross-sectional study evaluated gender differences in demographic, social, clinical, and epidemiologic characteristics of patients diagnosed with HIV/AIDS who were admitted for any reason to the Public Hospital of the Medical School of the Federal University of Triangulo Mineiro, Uberaba, Minas Gerais State, Brazil. Results: A total of 363 patients were included in the analysis, with a male/female ratio of 1.1:1.0. Forty-one percent of women were pregnant. Mean age at hospitalization and duration of hospitalization were significantly greater among men (P < 0.05). Men and nonpregnant women were admitted because of infection significantly more often than were pregnant women (P < 0.05). Significantly more single men who reported homosexual, bisexual, or heterosexual behavior associated with drug use were admitted compared with women (P < 0.05). Women admitted for treatment were significantly more likely than men to be employed (P < 0.05). Adherence to antiretroviral treatment and T CD4+ lymphocyte count indicated important differences between the sexes, with better parameters observed among nonpregnant and pregnant women compared with men. Conclusions: In the present study, women with HIV/AIDS who were admitted to the hospital for any reason were in better clinical condition compared with men. This observation may be partially explained by the proportion of pregnant women in the study population. These findings suggest that future studies should examine pregnant women with HIV/AIDS as a separate population group to avoid bias in analysis. (Gend Med. 2010;7:28-38) (C) 2010 Excerpta Medica Inc.

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We describe the long-term clinical outcome of a patient with Leigh-like syndrome presenting as an early onset encephalopathy and peripheral neuropathy caused by the T8993G mutation in the mitochondrial DNA (mtDNA). Clinical follow-up for 20 years revealed a peculiar pattern of slow disease progression, characterized by the addition of new minor deficits, while worsening of previous symptoms was mild. Brain MRI revealed cerebellar atrophy, diffuse demyelination of corona radiata and parietal white matter, and bilateral and symmetrical putaminal lesions. The proportion of mutant mtDNAs in blood was 72% (+/- 0.02%) and in skeletal muscle was 81% (+/- 0.4%). Leigh-like syndrome caused by the T8993G mtDNA mutation is a progressive disease, although not necessarily associated with an aggressive clinical course. (C) 2009 Elsevier B.V. All rights reserved.

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Purpose: To describe the clinical and radiologic features of orbital involvement in craniofacial brown tumors and to compare the rate of brown tumors in primary and secondary hyperparathyroidism. Methods: A retrospective hospital-based study of 115 patients with chronic kidney disease and secondary hyperparathyroidism and 34 with primary hyperparathyroidism was conducted. Laboratory results such as serum levels of alkaline phosphatase, calcium, phosphorus, and parathyroid hormone were recorded. Demographic data (age, sex, duration of disease) and image findings (bone scan scintigraphy, skull and long bone x-rays, CT) were also obtained. The main outcome measures were analysis of clinical, biochemical, and radiologic findings of all patients. Results: Of the 115 patients with chronic kidney disease, 10 (8.7%) had brown tumors in different bones of the skeleton. Five patients had lesions in the craniofacial bones. The maxilla, mandible, maxillary sinus, and nasal cavity were the most affected sites. The orbit was involved in 2 patients with lesions arising in the maxillary and ethmoid sinuses. One patient had facial leontiasis. All patients with brown tumors had extremely high levels of parathyroid hormone (>1,000 pg/ml, normal values 10-69 pg/ml) and alkaline phosphatase (>400 U/l, normal values 65-300 U/l). The mean serum levels of phosphorus and calcium were not abnormal among the patients with brown tumors. Age and time of renal failure were similar for patients with and without brown tumors. Among the patients with primary hyperparathyroidism, only 2 (5.8%) had brown tumors, and in just 1, the lesion was localized in the craniofacial skeleton. A 2-tailed Z test applied to compare the proportion of occurrence of brown tumors in the 2 groups revealed that the difference at the 90% of confidence level was not significant. Conclusions: Brown tumors are equally found in secondary and primary hyperparathyroidism. Craniofacial brown tumors involve the orbit, usually because of the osteodystrophy process that involves the maxilla and paranasal sinuses. The lesions do not necessarily need to be excised and may regress spontaneously after the control of hyperparathyroidism.

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Labetalol is clinically available as a mixture of two racemates (four stereoisomers). The stereoisomer (R,R) has as main activity the beta(1)-antagonism and the stereoisomer (S,R) is highly selective for the alpha(1) adrenoceptor and is responsible for most of the alpha-blocker activity. In the present investigation, a method for the analysis of labetalol stereoisomers in human plasma was developed and applied to pharmacokinetic studies. Plasma samples (0.5 ml) were extracted with methyl tert-butyl ether at pH 9.5. The four labetalol stereoisomers were analyzed by LC-MS/MS on a Chirobiotic (R) V column using a mobile phase consisting of methanol, acetic acid, and diethylamine, with a recovery of more than 90% for all four. The quantitation limit was 0.5 ng/ml and linearity was observed at 250 ng/ml plasma for each stereoisomer. Studies of precision and accuracy presented coefficients of variation and percentage inaccuracy of less than 15%, indicating that the method is precise and accurate. The method was applied to the study of the kinetic disposition of labetalol over a period of 12 h after oral administration of a single 100 mg dose to a hypertensive pregnant woman. The clinical study revealed stereoselectivity in the pharmacokinetics of labetalol, with a lower plasma proportion for the active stereoisomers (R,R)-labetalol and (S,R)-labetalol. The stereoselectivity observed after oral administration is due to the hepatic metabolism and the first pass effect, with an AUC((R,R))/AUC((S,S)) ratio of 0.5. Chirality 21:738-744, 2009. (C) 2008 Wiley-Liss, Inc.

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Objective To evaluate the reliability of two- and three-dimensional ultrasonographic measurement of the thickness of the lower uterine segment (LUS) in pregnant women by transvaginal and transabdominal approaches. Methods This was a study of 30 pregnant women who bad bad at least one previous Cesarean section and were between 36 and 39 weeks` gestation, with singleton pregnancies in cephalic presentation. Sonographic examinations were performed by two observers using both 4-7-MHz transabdominal and 5-8-MHz transvaginal volumetric probes. LUS measurements were performed using two- and three-dimensional ultrasound, evaluating the entire LUS thickness transabdominally and the LUS muscular thickness transvaginally. Each observer measured the LUS four times by each method. Reliability was analyzed by comparing the mean of the absolute differences, the intraclass correlation coefficients, the 95% limits of agreement and the proportion of differences <1 mm. Results Transvaginal ultrasound provided greater reliability in LUS measurements than did transabdominal ultrasound. The use of three-dimensional ultrasound improved significantly the reliability of the LUS muscular thickness measurement obtained transvaginally. Conclusions Ultrasonographic measurement of the LUS muscular thickness transvaginally appears more reliable than does that of the entire LUS thickness transabdominally. The use of three-dimensional ultrasound should be considered to improve measurement reliability. Copyright (c) 2009 ISUOG. Published by John Wiley & Sons, Ltd.

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Background. Patients with refractory epilepsy often have impaired quality of life (QOL) as a consequence of seizures and adverse effects of antiepileptic drugs. We assessed the impact of adverse effects on QOL and the utility of a structured instrument to help the physician manage adverse effects in patients with refractory epilepsy. Methods. Clinical characteristics, drug treatment and adverse effects were evaluated in 102 patients with refractory epilepsy at a single tertiary referral centre. The Adverse Events Profile (AEP) and Quality of Life in Epilepsy-31 (QOLIE-31) questionnaires were completed at baseline and after six months. At baseline, patients with a high burden of adverse effects (AEP scores >= 45) were randomized to an intervention or control group. AEP scores in the intervention group were available to the physician as an instrument to help to reduce adverse effects. Results. Ninety-five patients (93.1%) were on polytherapy. Sixty-six completed the questionnaires and, of these, 43 (65.1%) had a high AE burden and were randomized to the intervention and control group. QOLIE-31 scores were inversely correlated with AEP scores at both visits. Among randomized patients, AEP scores tended to decrease between the baseline and the final visit without significant differences between groups (intervention group: 54.1 +/- 6.1 vs 51.1 +/- 9.1; control group: 55.8 +/- 5.8 vs 50.5 +/- 12.2). QOLIE-31 scores did not change substantially between visits (intervention group: 45.9 +/- 17.4 vs 48.4 +/- 14; control group: 47.5 +/- 15.7 vs 45.2 +/- 18.9). Conclusion. A significant proportion of patients had a high toxicity burden which had an impact on their QOL. Reduction of over-treatment is a difficult challenge which cannot be addressed solely by providing a structured assessment of adverse effects, but requires a more comprehensive approach aimed at optimizing the many components of the management strategy.