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Various Subgroups (various + subgroup)
Selected AbstractsBerend Houwen Memorial Lecture: ISLH Las Vegas May 2009INTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 3 2009The pathogenesis, management of thrombotic microangiopathies Summary Thrombotic microangiopathies are a relatively rare group of congenital and inherited disorders caused by defects in processing the ultra large forms of von Willibrand factor which pathologically give rise to platelet rich microthrombi in the micro arterial circulation leading to end organ damage particularly in the brain, heart and kidneys. Identification of the ADAMTS 13 gene has led to the definition of congenital deficiency of its activity or failure of activity due to the development of an inhibitory IgG antibody. The idiopathic autoimmune form of the disease is the most common. There are various subgroups of acquired TTP associated with HIV infection, pregnancy, pancreatitis, associated with bone marrow transplantation, various disseminated malignancies and certain drugs, particularly Clopidogrel. Diagnostic assays are now becoming widely available to identify ADAMTS 13 activity and also acquired antibodies to the enzyme. Mainline treatment is associated with daily plasma exchange with associated other immunosuppressant treatments particularly steroids and recently the use of Rituximab, a monoclonal anti-CD20 antibody. Despite improvement in treatment modalities there is still significant mortality of 10,20%, particularly if there is a delay in initiating plasma exchange. Relapse also occurs in 20,50% of patients although this may be improved by Rituximab therapy. [source] Prevention of Postmenopausal Bone Loss by a Low-Magnitude, High-Frequency Mechanical Stimuli: A Clinical Trial Assessing Compliance, Efficacy, and Safety,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 3 2004Clinton Rubin Abstract A 1-year prospective, randomized, double-blind, and placebo-controlled trial of 70 postmenopausal women demonstrated that brief periods (<20 minutes) of a low-level (0.2g, 30 Hz) vibration applied during quiet standing can effectively inhibit bone loss in the spine and femur, with efficacy increasing significantly with greater compliance, particularly in those subjects with lower body mass. Introduction: Indicative of the anabolic potential of mechanical stimuli, animal models have demonstrated that short periods (<30 minutes) of low-magnitude vibration (<0.3g), applied at a relatively high frequency (20,90 Hz), will increase the number and width of trabeculae, as well as enhance stiffness and strength of cancellous bone. Here, a 1-year prospective, randomized, double-blind, and placebo-controlled clinical trial in 70 women, 3,8 years past the menopause, examined the ability of such high-frequency, low-magnitude mechanical signals to inhibit bone loss in the human. Materials and Methods: Each day, one-half of the subjects were exposed to short-duration (two 10-minute treatments/day), low-magnitude (2.0 m/s2 peak to peak), 30-Hz vertical accelerations (vibration), whereas the other half stood for the same duration on placebo devices. DXA was used to measure BMD at the spine, hip, and distal radius at baseline, and 3, 6, and 12 months. Fifty-six women completed the 1-year treatment. Results and Conclusions: The detection threshold of the study design failed to show any changes in bone density using an intention-to-treat analysis for either the placebo or treatment group. Regression analysis on the a priori study group demonstrated a significant effect of compliance on efficacy of the intervention, particularly at the lumbar spine (p = 0.004). Posthoc testing was used to assist in identifying various subgroups that may have benefited from this treatment modality. Evaluating those in the highest quartile of compliance (86% compliant), placebo subjects lost 2.13% in the femoral neck over 1 year, whereas treatment was associated with a gain of 0.04%, reflecting a 2.17% relative benefit of treatment (p = 0.06). In the spine, the 1.6% decrease observed over 1 year in the placebo group was reduced to a 0.10% loss in the active group, indicating a 1.5% relative benefit of treatment (p = 0.09). Considering the interdependence of weight, the spine of lighter women (<65 kg), who were in the highest quartile of compliance, exhibited a relative benefit of active treatment of 3.35% greater BMD over 1 year (p = 0.009); for the mean compliance group, a 2.73% relative benefit in BMD was found (p = 0.02). These preliminary results indicate the potential for a noninvasive, mechanically mediated intervention for osteoporosis. This non-pharmacologic approach represents a physiologically based means of inhibiting the decline in BMD that follows menopause, perhaps most effectively in the spine of lighter women who are in the greatest need of intervention. [source] Gray-scale sonography of solid breast masses: Diagnosis of probably benign masses and reduction of the number of biopsiesJOURNAL OF CLINICAL ULTRASOUND, Issue 1 2007Luciano Chala MD Abstract Purpose. To identify probably benign breast masses using gray-scale sonography and to see if this strategy could reduce the number of biopsies of breast masses. Methods. This retrospective study included 229 masses in 203 women who underwent sonographically guided percutaneous biopsy. Masses with a negative predictive value for malignancy >98% were retrospectively considered probably benign, and the potential impact of gray-scale sonography in reducing the number of biopsies if these masses were not biopsied was assessed. Assessments were performed considering all masses as a group as well as various subgroups. Results. Round, ellipsoid, or lobulated masses with 3 or fewer lobulations, circumscribed margins, a longitudinal,anteroposterior diameter ratio ,1.0 and no marked hypoechogenicity, posterior acoustic shad owing, internal microcalcifications, or altered surrounding breast tissue were considered probably benign. The sensitivity of gray-scale sonography to identify this subgroup was 98%, with a negative predictive value of 99%. If these masses were not biopsied, there would be a 42% reduction in the number of biopsies considering all masses, a 36% reduction for masses classified as Breast Imaging Reporting and Data System category 4, and a 59% reduction for masses exclusively analyzed with sonography. Conclusions. It is possible to identify probably benign breast masses using gray-scale sonography, and thereby to reduce the number of biopsies performed. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound 2007 [source] Effects of different food restrictions on somatic and otolith growth in Nile tilapia reared under controlled conditionsJOURNAL OF FISH BIOLOGY, Issue 5 2002A. M. Massou .Nile tilapia Oreochromis niloticus, initial age 12 days, were given an unrestricted (NR) or restricted (R) ration over 93 days which resulted in fish of very different sizes although the body condition factor (K) and the viscero-somatic index (IV) remained almost unchanged. In a second stage (64 days) each group (NR & R) was divided into three subgroups that were subjected to 0 (NR0, R0), 15 (NR15, R15) and 30 (NR30, R30) days of food restriction, respectively. The impact of the different treatments on the somatic growth during the second stage of the experiment had an effect, with a highly significant difference between the mean ± S.D. masses (MT) in the different subgroups (NR0= 115.0 ± 26.6 g; NR15 = 94.8 ± 24.9 g; NR30 = 56.3 ± 28 g; R0 = 76.4 ± 20.1 g; R15 = 72.l ± 17.6 g; R30 = 43.6 ± 17.2 g). Similarly, K and IV decreased. Irrespective of the initial feeding condition, the width of the otolith microincrements started to decrease at the end of the first or second day of restricted feeding. In the subgroups given a restricted food ration for 30 days (NR30 and R30), this decrease reached a plateau at about day 30, which was maintained even when the restriction had ended. This slowed growth did not lead to any marked halt in microincrement formation, since there were no significant differences (ANOVA; P>0.05) in the numbers of increments counted in the various subgroups. The results show that in 153 day old fish, a period of severe food restriction, even if prolonged (15 to 30 days), had no influence on the timing of the laying down of microincrements but only affected their growth. [source] Meta-analysis: levamisole improves the immune response to hepatitis B vaccine in dialysis patientsALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 6 2010F. Fabrizi Summary Background, Patients undergoing maintenance dialysis often fail to mount protective antibodies to hepatitis B virus surface antigen (HBsAg) following vaccination against hepatitis B virus (HBV). Some authors have suggested that levamisole improves immune response to HBV vaccine in dialysis population. However, consistent information on this issue does not exist. Aim, To evaluate efficacy and safety of levamisole as adjuvant to hepatitis B virus (HBV) vaccine in dialysis patients by performing a systematic review of the literature with a meta-analysis of clinical trials. Methods, We used the random-effects model of DerSimonian and Laird, with heterogeneity and sensitivity analyses. Only trials comparing the seroresponse rate in study subjects (levamisole plus HBV vaccine) vs. controls (HBV vaccine alone) were included. The end point of interest was the rate of patients showing seroprotective anti-hepatitis B titres at completion of HBV vaccine schedule in study vs. control groups. Results, We identified four studies involving 328 unique patients on regular dialysis. Only prospective, randomized clinical trials (RCTs) were included. Pooling of study results showed a significant increase in response rates among study (levamisole plus HBV vaccine) vs. control (HBV vaccine alone) patients; the pooled Odds Ratio was 2.432 (95% Confidence Intervals, 1.34; 4.403), P = 0.002. No study heterogeneity was found. These results did not change in various subgroups of interest. Conclusions, Our meta-analysis showed that levamisole significantly improves immune response to hepatitis B vaccine in dialysis population. The limited number of patients precluded more conclusions. [source] Statistical Inference and Changes in Income Inequality in AustraliaTHE ECONOMIC RECORD, Issue 247 2003George Athanasopoulos This paper studies the changes in income inequality in Australia between 1986 and 1999, using the Gini coefficient and Theil's inequality measure. Individuals are divided into various subgroups along several dimensions, namely region of residence, employment status, occupation and age. The change in inequality over time, between and within these subgroups is studied, and the bootstrap method is used to establish whether these changes are statistically significant. [source] Structures of mono-unsaturated triacylglycerols.ACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2008The ,-2 crystal structures of a series of saturated and trans -mono-unsaturated triacylglycerols (TAGs) have been solved from high-resolution powder synchrotron diffraction data. The series comprises symmetric as well as asymmetric even-numbered TAGs and the trans -mono-unsaturated ones all have a single elaidoyl chain. The structures have been solved with the direct-space parallel-tempering program FOX and refined with the Rietveld program GSAS. The ,-2 structures all crystallized in the space group with the same molecular conformation. Within the resolution of the data no significant difference in packing or conformation is observed between trans -mono-unsaturated TAGs and saturated (stearoyl or palmitoyl) chain-containing analogues, in spite of the lower melting points of the former. An analysis of the position of the stepped methyl end-plane in the various subgroups of TAGs confirms most but not all suppositions found in the literature. [source] Identifying Subjects Who Benefit from Additional Information for Better Prediction of the Outcome VariablesBIOMETRICS, Issue 3 2009L. Tian Summary Suppose that we are interested in using new bio- or clinical markers, in addition to the conventional markers, to improve prediction or diagnosis of the patient's clinical outcome. The incremental value from the new markers is typically assessed by averaging across patients in the entire study population. However, when measuring the new markers is costly or invasive, an overall improvement does not justify measuring the new markers in all patients. A more practical strategy is to utilize the patient's conventional markers to decide whether the new markers are needed for improving prediction of his/her health outcomes. In this article, we propose inference procedures for the incremental values of new markers across various subgroups of patients classified by the conventional markers. The resulting point and interval estimates can be quite useful for medical decision makers seeking to balance the predictive or diagnostic value of new markers against their associated cost and risk. Our proposals are theoretically justified and illustrated empirically with two real examples. [source] | ||||||||||