A Log-Linear Regression Model for the Beta-Weibull Distribution

We introduce the log-beta Weibull regression model based on the beta Weibull distribution (Famoye et al., 2005; Lee et al., 2007). We derive expansions for the moment generating function which do not depend on complicated functions. The new regression model represents a parametric family of models that includes as sub-models several widely known regression models that can be applied to censored survival data. We employ a frequentist analysis, a jackknife estimator, and a parametric bootstrap for the parameters of the proposed model. We derive the appropriate matrices for assessing local influences on the parameter estimates under different perturbation schemes and present some ways to assess global influences. Further, for different parameter settings, sample sizes, and censoring percentages, several simulations are performed. In addition, the empirical distribution of some modified residuals are displayed and compared with the standard normal distribution. These studies suggest that the residual analysis usually performed in normal linear regression models can be extended to a modified deviance residual in the proposed regression model applied to censored data. We define martingale and deviance residuals to evaluate the model assumptions. The extended regression model is very useful for the analysis of real data and could give more realistic fits than other special regression models.

Orange juice decreases low-density lipoprotein cholesterol in hypercholesterolemic subjects and improves lipid transfer to high-density lipoprotein in normal and hypercholesterolemic subjects

Orange juice (OJ) is regularly consumed worldwide, but its effects on plasma lipids have rarely been explored. This study hypothesized that consumption of OJ concentrate would improve lipid levels and lipid metabolism, which are important in high-density lipoprotein (HDL) function in normolipidemic (NC) and hypercholesterolemic (HCH) subjects. Fourteen HCH and 31 NC adults consumed 750 mL/day OJ concentrate (1:6 OJ/water) for 60 days. Eight control subjects did not consume OJ for 60 days. Plasma was collected before and on the last clay for biochemical analysis and an in vitro as

Moisture sorption isotherm characteristics of freeze-dried D-limonene emulsions in modified chitosan and maltodextrin

This article reports on modified chitosan as an alternative substance for protecting loss of volatile compounds during freeze drying. Moisture sorption isotherms of freeze-dried D-limonene emulsions in modified chitosan were determined at 15, 25, and 35 degrees C. The data were adjusted to the GAB model. Maltodextrin was used in a parallel experiment. Flavor released from microcapsules was measured. The monolayer humidity, the sorption heat, the diffusivity coefficients, and the surface area of freeze-dried D-limonene emulsions were determined.

Impact of cholesterol on ABC and SLC transporters expression and function and its role in disposition variability to lipid-lowering drugs

This report focuses on the effects of cholesterol on the expression and function of the ATP-binding cassette (ABCB1, ABCG2 and ABCC2) and solute-linked carrier (SLCO1B1 and SLCO2B1) drug transporters with a particular focus on the potential impact of cholesterol on lipid-lowering drug disposition. Statins are the most active agents in the treatment of hypercholesterolemia. However, considerable interindividual variation exists in the response to statin therapy. Therefore, it would be huge progress if factors were identified that reliably differentiate between responders and nonresponders. Many studies have suggested that plasma lipid concentrations can affect drug disposition of compounds, such as ciclosporin and amphotericin B. Both compounds are able to affect the expression and function of ABC transporters. Although still speculative, these effects might be owing to the regulation of drug transporters by plasma cholesterol levels. Studies with normo- and hyper-cholesterolemic individuals, before and after atorvastatin treatment, have demonstrated that plasma cholesterol levels are correlated with drug transporter expression, as well as being related to atorvastatin`s cholesterol-lowering effect. The mechanism influencing the correlation between cholesterol levels and the expression and function of drug transporters remains unclear. Some studies provide strong evidence that nuclear receptors, such as the pregnane X receptor and the constitutive androstane receptor, mediate this effect. In the near future, pharmacogenomic studies with individuals in a pathological state should be performed in order to identify whether high plasma cholesterol levels might be a factor contributing to interindividual oral drug bioavailability.

Cardiac resynchronization therapy evaluated by myocardial scintigraphy with (99m)Tc-MIBI: changes in left ventricular uptake, dyssynchrony, and function

(99m)Tc-MIBI gated myocardial scintigraphy (GMS) evaluates myocyte integrity and perfusion, left ventricular (LV) dyssynchrony and function. Cardiac resynchronization therapy (CRT) may improve the clinical symptoms of heart failure (HF), but its benefits for LV function are less pronounced. We assessed whether changes in myocardial (99m)Tc-MIBI uptake after CRT are related to improvement in clinical symptoms, LV synchrony and performance, and whether GMS adds information for patient selection for CRT. A group of 30 patients with severe HF were prospectively studied before and 3 months after CRT. Variables analysed were HF functional class, QRS duration, LV ejection fraction (LVEF) by echocardiography, myocardial (99m)Tc-MIBI uptake, LV end-diastolic volume (EDV) and end-systolic volume (ESV), phase analysis LV dyssynchrony indices, and regional motion by GMS. After CRT, patients were divided into two groups according to improvement in LVEF: group 1 (12 patients) with increase in LVEF of 5 or more points, and group 2 (18 patients) without a significant increase. After CRT, both groups showed a significant improvement in HF functional class, reduced QRS width and increased septal wall (99m)Tc-MIBI uptake. Only group 1 showed favourable changes in EDV, ESV, LV dyssynchrony indices, and regional motion. Before CRT, EDV, and ESV were lower in group 1 than in group 2. Anterior and inferior wall (99m)Tc-MIBI uptakes were higher in group 1 than in group 2 (p < 0.05). EDV was the only independent predictor of an increase in LVEF (p=0.01). The optimal EDV cut-off point was 315 ml (sensitivity 89%, specificity 94%). The evaluation of EDV by GMS added information on patient selection for CRT. After CRT, LVEF increase occurred in hearts less dilated and with more normal (99m)Tc-MIBI uptake.

Are Total Prostate-specific Antigen Serum Levels in Cirrhotic Men Different From Those in Normal Men?

OBJECTIVES To determine the serum total prostate-specific antigen (tPSA) levels in cirrhotic men and compare them with those in noncirrhotic men. METHODS We prospectively evaluated 113 cirrhotic patients listed for liver transplantation using the serum tPSA, total testosterone level, and Child-Pugh liver function score according to age and severity of liver disease. The tPSA levels were compared with those of 661 healthy men. The Mann-Whitney U test was used for statistical analysis, with a significance level of .05. RESULTS The median age of the cirrhotic and noncirrhotic patients was 55 years (range 28-70) and 58 years (range 46-70), respectively (P <.01). However, when stratified by age group (<49, 50-59, and >60 years), this difference was not significant. The median serum tPSA level was 0.3 ng/mL (range 0.04-9-9) and 1.3 ng/mL (range 0.04-65.8) in the cirrhotic and noncirrhotic group, respectively (P <.0001). Stratifying both groups according to age, the cirrhotic patients had significantly lower tPSA levels than did the noncirrhotic patients. According to the Child-Pugh score (A,B, and C), Child-Pugh class C patients had significantly lower tPSA levels than did Child-Pugh class A patients and also had lower testosterone levels than did Child-Pugh class A and B patients. The tPSA levels correlated significantly with the testosterone levels in the cirrhotic patients (P =.028). CONCLUSIONS The results of our study have shown that cirrhotic patients have approximately 4 times lower serum tPSA levels than noncirrhotic men. Patients with more severe liver disease have lower tPSA and testosterone levels than patients less affected. The tPSA levels in cirrhotic men are affected by the total testosterone levels. UROLOGY 73: 1032-1035, 2009. (C) 2009 Elsevier Inc.

Testicular Sertoli cell function in male systemic lupus erythematosus

Objective. To assess the testicular Sertoli cell function in male SLE patients. Methods. Thirty-four consecutive patients were prospectively selected to evaluate serum inhibin B. Clinical features, treatment, semen analysis, urological evaluation, testicular ultrasound, hormones and anti-sperm antibodies were determined. Results. Patients were subdivided into two groups: low serum inhibin B (Group 1, n = 8) and normal levels (Group 2, n 26). The median sperm concentration (P = 0.024), total sperm count (P = 0.023) and total motile sperm count (P = 0.025) were lower in Group 1. Inhibin B levels were positively correlated with sperm concentration (r = 0.343), total motile sperm count (r = 0.357), and negatively correlated with follicule-stimulating hormone (FSH) (r = 0.699) and luteinizing hormone (r = 0.397). The median serum inhibin B was lower in SLE patients treated with intravenous cyclophosphamide (IVCYC) compared with those without this therapy (P = 0.031). Further evaluation of the 26 SLE patients with normal inhibin B and FSH levels revealed that medians of inhibin B/FSH ratio were lower in SLE patients with oligozoospermia compared with normozoospermia (P = 0.004). This ratio was also lower in SLE patients treated with IVCYC than those without this therapy (P = 0.04). In contrast, inhibin B serum level alone did not discriminate the later group of patients (P = 0.12). Conclusions. This is the first study to identify a high frequency of testicular Sertoli cell dysfunction in male SLE associated with semen abnormalities. Further prospective studies are necessary to determine if inhibin levels and inhibin B/FSH ratio will be an earlier and useful marker of IVCYC toxicity in these patients.

Mandibular Function is Severely Impaired in Systemic Sclerosis Patients

Aims: To evaluate the presence of temporomandibular disorders (TMD) in systemic sclerosis (SSc) patients and its possible association with the severity of skin involvement. Methods: The presence of TMD was evaluated in 35 SSc women and 30 age- and sex-matched healthy controls by means of the anamnestic (A(i)) and clinical (D(i)) Helkimo indices; the jaw mobility was further analyzed (M(I)). Skin involvement was scored by the Modified Rodnan Skin Score (MRSS). Results: Signs and symptoms of TMD were more frequent in SSc patients than in controls, the frequency distribution of the different clinical dysfunction indices differing significantly (P < .001) between patients (D(i)0 8.6%, D(i)I 48.6%, D(i)II 22.8%, and D(i)III 20%) and controls (D(i)0 50%, D(i)I 33.3%, and D(i)II 16.7%). Cyclophosphamide for severe and rapidly progressive cutaneous fibrosis was prescribed in six out of seven patients with severe signs (D(i)III), in contrast this treatment was indicated for only two out of 25 patients with mild to moderate signs (D(i)I and D(i)II, P <. 001). Impaired jaw mobility was more frequent in SSc patients than controls (P < .001). It was severe in 77.1% (M(I)II) and mild in 22.9% (M(1)I) of the cases, in contrast to controls (M(I)0 33.4%, M(I)I 53.3%, and M(I)II 13.3%; P < .001). Approximately half of SSc patients with severe (M(I)II) but none of those with mild impairment were on cyclophosphamide treatment for severe cutaneous fibrosis (P = .02). Conclusion: Severe signs of TMD according to the anamnestic and clinical Helkimo indices were very frequent in SSc patients. J OROFAC PAIN 2010;24:197-202

Lung Diffusing Capacity Relates Better to Short-Term Progression on HRCT Abnormalities Than Spirometry in Mild Asbestosis

Background Pulmonary function tests (PFT), particularly spirometry and lung diffusing capacity for carbon monoxide (DL(CO)), have been considered useful methods for the detection of the progression of interstitial asbestos abnormalities as indicated by high-resolution computed tomography (HRCT). However, it is currently unknown which of these two tests correlates best with anatomical changes over time. Methods In this study, we contrasted longitudinal changes (3-9 years follow-up) in PFTs at rest and during exercise with interstitial abnormalities evaluated by HRCT in 63 ex-workers with mild-to-moderate asbestosis. Results At baseline, patients presented with low-grade asbestosis (Huuskonen classes I-II), and most PFT results were within the limits of normality. In the follow-up, most subjects had normal spirometry, static lung volumes and arterial blood gases. In contrast, frequency of DL(CO) abnormalities almost doubled (P < 0.05). Twenty-three (36.5%) subjects increased the interstitial marks on HRCT. These had significantly larger declines in DL(CO) compared to patients who remained stable (0.88 vs. 0.31 ml/min/mm Hg/year and 3.5 vs. 1.2%/year, respectively; P < 0.05). In contrast, no between-group differences were found for the other functional tests, including spirometry (P > 0.05). Conclusions These data demonstrate that the functional consequences of progression of HRCT abnormalities in mild-to-moderate asbestosis are better reflected by decrements in DL(CO) than by spirometric changes. These results might have important practical implications for medico-legal evaluation of this patient population. Am. J. Ind. Med. 54:185-193, 2011. (c) 2010 Wiley-Liss, Inc.

Subclinical Regional Left Ventricular Dysfunction in Obese Patients With and Without Hypertension or Hypertrophy

We investigated the impact of obesity on the abnormalities of systolic and diastolic regional left ventricular (LV) function in patients with or without hypertension or hypertrophy, and without heart failure. We studied 120 individuals divided into 6 groups of 20 patients (42 +/- 6 years, 60 females) using standard and pulsed-wave tissue Doppler imaging (TDI) echocardiography, and heterogeneity index (HI): nonobese (I: no hypertension, no hypertrophy, control group; II: hypertension, no hypertrophy; III: hypertension and hypertrophy) and obese (IV: no hypertension, no hypertrophy; V: hypertension, no hypertrophy; VI: hypertension and hypertrophy). The criterion for obesity was BMI >= 30 kg/m(2), for hypertension was blood pressure >= 140/90 mm Hg, for hypertrophy in nonobese was LV mass/body surface area (BSA) >134 g/m(2) (men) and >110 mg/m(2) (women), and in obese was LV mass/height((2.7)) >50 (men) and >40 (women). Obese groups had normal LV ejection fraction compared with nonobese groups, but decreased longitudinal and radial systolic myocardial peak velocities (S`), and early diastolic myocardial peak velocity (E`). Also, a great variability of E` and late diastolic myocardial peak velocity (A`) from the longitudinal basal region was observed in obese groups (E` basal nonobese: 11 +/- 7 vs. obese 19 +/- 11, P < 0.001, A` basal nonobese: 7 +/- 4 vs. obese 11 +/- 7, P < 0.001). Our findings were more evident when comparing groups IV with V and VI, with the latter having concentric hypertrophy and obvious segmental systolic and diastolic dysfunctions. Subclinical myocardial alterations and increased variability of the velocities were observed in obese groups, especially with hypertension and hypertrophy, reflecting impaired regional LV relaxation, segmental atrial, and systolic dysfunctions.

Left ventricular Systolic function and outcome after in-hospital cardiac arrest

Background - The effect of prearrest left ventricular ejection fraction ( LVEF) on outcome after cardiac arrest is unknown. Methods and Results - During a 26-month period, Utstein-style data were prospectively collected on 800 consecutive inpatient adult index cardiac arrests in an observational, single-center study at a tertiary cardiac care hospital. Prearrest echocardiograms were performed on 613 patients ( 77%) at 11 +/- 14 days before the cardiac arrest. Outcomes among patients with normal or nearly normal prearrest LVEF ( >= 45%) were compared with those of patients with moderate or severe dysfunction ( LVEF < 45%) by chi(2) and logistic regression analyses. Survival to discharge was 19% in patients with normal or nearly normal LVEF compared with 8% in those with moderate or severe dysfunction ( adjusted odds ratio, 4.8; 95% confidence interval, 2.3 to 9.9; P < 0.001) but did not differ with regard to sustained return of spontaneous circulation ( 59% versus 56%; P = 0.468) or 24-hour survival ( 39% versus 36%; P = 0.550). Postarrest echocardiograms were performed on 84 patients within 72 hours after the index cardiac arrest; the LVEF decreased 25% in those with normal or nearly normal prearrest LVEF ( 60 +/- 9% to 45 +/- 14%; P < 0.001) and decreased 26% in those with moderate or severe dysfunction ( 31 +/- 7% to 23 +/- 6%, P < 0.001). For all patients, prearrest beta-blocker treatment was associated with higher survival to discharge ( 33% versus 8%; adjusted odds ratio, 3.9; 95% confidence interval, 1.8 to 8.2; P < 0.001). Conclusions - Moderate and severe prearrest left ventricular systolic dysfunction was associated with substantially lower rates of survival to hospital discharge compared with normal or nearly normal function.

Glycosaminoglycan chains from alpha(5)beta(1) integrin are involved in fibronectin-dependent cell migration

alpha(5)beta(1) integrin from both wild-type CHO cells (CHO-K1) and deficient in proteoglycan biosynthesis (CHO-745) is post-translationally modified by glycosaminoglycan chains. We demonstrated this using [(35)S]sulfate metabolic labeling of the cells, enzymatic degradation, immunoprecipitation reaction with monoclonal antibody, fluorescence microscopy, and flow cytometry. The alpha(5)beta(1) integrin heterodimer is a hybrid proteoglycan containing both chondroitin and heparan sulfate chains. Xyloside inhibition of sulfate incorporation into alpha(5)beta(1) integrin also supports that integrin is a proteoglycan. Also. cells grown with xyloside adhered on fibronectin with no alteration in alpha(5)beta(1) integrin expression. However, haptotactic motility on fibronectin declined in cells grown with xyloside or chlorate as compared with controls. Thus, alpha(5)beta(1) integrin is a proteoglycan and the glycosaminoglycan chains of the integrin influence cell motility on fibronectin. Similar glycosylation of alpha(5)beta(1) integrin was observed in other normal and malignant cells, suggesting that this modification is conserved and important in the function of this integrin. Therefore, these glycosaminoglycan chains of alpha(5)beta(1) integrin are involved in cellular migration on fibronectin.

Influence of Cochlear Function on Auditory Temporal Resolution in Tinnitus Patients

Our aim was to analyze the influence of subtle cochlear damage on temporal auditory resolution in tinnitus patients. Forty-eight subjects (hearing threshold <= 25 dB HL) were assigned to one of two experimental groups: 28 without auditory complaints (mean age, 28.8 years) and 20 with tinnitus (mean age, 33.5 years). We analyzed distortion product otoacoustic emission growth functions (by threshold, slope, and estimated amplitude), extended high-frequency thresholds, and the Gaps-in-Noise test. There were differences between the groups, principally in the extended high-frequency thresholds and the Gaps-in-Noise test results. Our findings suggest that subtle peripheral hearing impairment affects temporal resolution in tinnitus, even when pure-tone thresholds as conventionally measured appear normal. Copyright (C) 2010 S. Karger AG, Basel

Tone-evoked ABR in full-term and preterm neonates with normal hearing

This study was designed to investigate the feasibility of applying tone-ABRs in the nursery and neonatal intensive care unit (NICU), and to provide normative tone-ABR data from neonates. Normative tone-ABR latency data were determined. The study obtained intensity series of tone-ABRs from thirty preterm neonates and twenty fullterm neonates who had confirmed normal peripheral auditory function after passing both an OAE and ABR screening examination. ABRs were collected in response to 500, 1500, and 4000 Hz tone bursts at 70, 50, 30, and 20 dB nHL. Mean wave V latencies were compared between groups, ears, and by gender. Responses to tone bursts of 20 and 30 dB nHL were detected in 97% and 100% of all ears respectively, in addition to responses to the higher-intensity stimuli. Preterm neonates` ABRs showed significantly longer latencies than those of the full-term infants. Tone-ABR evaluation was found to be both feasible and reliable as a measure of auditory function in neonates.

Spirometric Function Improves in the Morbidly Obese After 1-Year Post-surgery

Obesity can negatively affect pulmonary function tests, with or without clinical symptoms, but the impact of bariatric weight loss is still debated. Aiming to document such profile in a consecutive homogeneous population, a prospective cohort study was undertaken. Sixty-one patients (100% females, age 40 +/- 8 years, BMI 49 +/- 5 kg/m(2) and without respiratory disease) were enrolled. Spirometric analysis was carried out to compare preoperative respiratory pattern with outcome after 6 and 12 months. Variables included vital capacity (VC), expiratory reserve volume (ERV), forced expiratory volume (1 s) (FEV1), FEV1/FVC ratio and maximum voluntary ventilation (MVV). Correlation of results with weight loss was examined. The following initial variables exhibited significant difference when compared to the 12-month postoperative control: FVC (P = 0.0308), FEV1/FVC (P = 0.1998), MVV (P = 0.0004) and ERV (P = 0.2124). Recovery of FVC and FEV1/FVC occurred earlier by 6 months. The most seriously depressed preoperative finding was ERV, which even after 1 year still remained inadequate. (1) Pulmonary limitations were diagnosed in approximately one third of the population. (2) Changes were demonstrated for FVC, FEV1/FVC, ERV and MVV. (3) FEV1 and FEV1/FVC were acceptable due to the absence of an obstructive pattern. (4) Two variables increased by 6 months (FEV1/FVC and ERV), whereas recovery for others was confirmed after 1 year. (5) The only exception was ERV which continued below the acceptable range.