A sequential test procedure for monitoring a singular safety and efficacy outcome

In this note we describe a modification of the sequential probability ratio test (SPRT) developed for the purpose of “flagging” a significant increase in the mortality rate of a treatment relative to a control while ensuring that double-blinding and the Type I error for the primary test of efficacy, also based on mortality rates, is not compromised. Key words: Interim analysis; safety monitoring; sequential testing. Trop J Pharm Res, December 2003; 2(2): 197-20

A Characterization of Most(More) Powerful Test Statistics with Simple Nonparametric Applications

Data-driven most powerful tests are statistical hypothesis decision-making tools that deliver the greatest power against a fixed null hypothesis among all corresponding data-based tests of a given size. When the underlying data distributions are known, the likelihood ratio principle can be applied to conduct most powerful tests. Reversing this notion, we consider the following questions. (a) Assuming a test statistic, say T, is given, how can we transform T to improve the power of the test? (b) Can T be used to generate the most powerful test? (c) How does one compare test statistics with respect to an attribute of the desired most powerful decision-making procedure? To examine these questions, we propose one-to-one mapping of the term 'Most Powerful' to the distribution properties of a given test statistic via matching characterization. This form of characterization has practical applicability and aligns well with the general principle of sufficiency. Findings indicate that to improve a given test, we can employ relevant ancillary statistics that do not have changes in their distributions with respect to tested hypotheses. As an example, the present method is illustrated by modifying the usual t-test under nonparametric settings. Numerical studies based on generated data and a real-data set confirm that the proposed approach can be useful in practice.Comment: Accepte

Down-regulation of Cdc6, a cell cycle regulatory gene, in prostate cancer

CDC6 plays a critical role in regulation of the onset of DNA replication in eukaryotic cells. We have found that Cdc6 expression is down-regulated in prostate cancer as detected by semiquantitative reverse transcriptase-PCR of prostate cell lines and laser-captured microdissected prostate tissues. This result was substantiated by immunohistochemical analysis of paraffin-embedded tissue sections and immunoblot analysis of benign (BPH-1) and adenocarcinomatous prostatic cells. Furthermore, a 100-fold reduction in the transcription efficiency of the Cdc6 promoter-luciferase construct was noted in the metastatic PC3 cells compared with that in BPH-1 cells. Concentration of the E2F and Oct1 transcription factors that have putative binding sites in the Cdc6 promoter was substantially low in PC3 cells compared with BPH cells. Mutagenesis of the two E2F binding sites on the Cdc6 promoter resulted in increased promoter activity in PC3 cells owing to elimination of the negative regulation by pRb-E2F complex but not to the level of that obtained in BPH cells. We conclude that an altered interaction of transcription factors may be responsible for the down-regulation of Cdc6 transcription in PC3 cells. Our study suggests a potential use of the lack of CDC6 expression as an index of prostate cancer development

Down-regulation of Cdc6, a cell cycle regulatory gene, in prostate cancer

CDC6 plays a critical role in regulation of the onset of DNA replication in eukaryotic cells. We have found that Cdc6 expression is down-regulated in prostate cancer as detected by semiquantitative reverse transcriptase-PCR of prostate cell lines and laser-captured microdissected prostate tissues. This result was substantiated by immunohistochemical analysis of paraffin-embedded tissue sections and immunoblot analysis of benign (BPH-1) and adenocarcinomatous prostatic cells. Furthermore, a 100-fold reduction in the transcription efficiency of the Cdc6 promoter-luciferase construct was noted in the metastatic PC3 cells compared with that in BPH-1 cells. Concentration of the E2F and Oct1 transcription factors that have putative binding sites in the Cdc6 promoter was substantially low in PC3 cells compared with BPH cells. Mutagenesis of the two E2F binding sites on the Cdc6 promoter resulted in increased promoter activity in PC3 cells owing to elimination of the negative regulation by pRb-E2F complex but not to the level of that obtained in BPH cells. We conclude that an altered interaction of transcription factors may be responsible for the down-regulation of Cdc6 transcription in PC3 cells. Our study suggests a potential use of the lack of CDC6 expression as an index of prostate cancer development

A Pilot Study of Urokinase-Type Plasminogen Activator (uPA) Overexpression in the Brush Cytology of Patients with Malignant Pancreatic or Biliary Strictures

We have previously demonstrated that uPA is overexpressed in pancreatic tumors. In an attempt to diagnose these tumors earlier, we sought to determine whether uPA could be identified in endoscopic retrograde cholangiopancreatography obtained brushings in patients with malignant pancreatic and biliary strictures. Secondarily, uPA was measured in the serum of this patient population. uPA overexpression was identified in the cytologic tissue in 8 of 11 patients (72.7%). Serum analysis demonstrated a 2-fold higher concentration of uPA in the pancreaticobiliary cancer patients (1.27 versus 0.56 ng/mL; P = .0182). Also, uPA overexpression correlated with serum levels (P < .0001). This study confirms that uPA can be detected in the ERCP cytologically obtained tissue and is frequently present in a higher concentration in the serum of pancreaticobiliary cancer patients. A larger sample size will be required to address its value as a sensitive marker for the diagnosis of pancreatic or biliary cancers

Effectiveness of a psychological intervention delivered by general nurses for alcohol use disorders in people living with HIV in Zimbabwe: a cluster randomized controlled trial.

INTRODUCTION: There have been very few randomized clinical trials of interventions for alcohol use disorders (AUD) in people living with HIV (PLWH) in African countries. This is despite the fact that alcohol use is one of the modifiable risk factors for poor virological control in PLWH on antiretroviral therapy. METHODS: Sixteen clinic clusters in Zimbabwe were selected through stratified randomization and randomized 1: 1 to Intervention and Control arms. Inclusion criteria for individual participants were being adult, living with HIV and a probable alcohol use disorder as defined by a score of 6 (women) or 7 (men) on the Alcohol Use Disorders Identification Test (AUDIT). In the Intervention clusters, participants received 8 to 10 sessions of Motivational Interviewing blended with brief Cognitive Behavioural Therapy (MI-CBT). In the control clusters, participants received four Enhanced Usual Care (EUC) sessions based on the alcohol treatment module from the World Health Organisation mhGAP intervention guide. General Nurses from the clinics were trained to deliver both treatments. The primary outcome was a change in AUDIT score at six-month post-randomization. Viral load, functioning and quality of life were secondary outcomes. A random-effects analysis-of-covariance model was used to account for the cluster design. RESULTS: Two hundred and thirty-four participants (n = 108 intervention and n = 126 control) were enrolled across 16 clinics. Participants were recruited from November 2016 to November 2017 and followed through to May 2018. Their mean age was 43.3 years (SD = 9.1) and 78.6% (n = 184) were male. At six months, the mean AUDIT score fell by -6.15 (95% CI -6.32; -6.00) in the MI-CBT arm, compared to a fall of - 3.09 95 % CI - 3.21; -2.93) in the EUC arm (mean difference -3.09 (95% CI -4.53 to -1.23) (p = 0.05). Viral load reduced and quality of life and functioning improved in both arms but the difference between arms was non-significant. CONCLUSIONS: Interventions for hazardous drinking and AUD comprising brief, multiple alcohol treatment sessions delivered by nurses in public HIV facilities in low-income African countries can reduce problematic drinking among PLWH. Such interventions should be integrated into the primary care management of AUD and HIV and delivered by non-specialist providers. Research is needed on cost-effectiveness and implementation of such interventions, and on validation of cut-points for alcohol use scales in low resource settings, in partnership with those with lived experience of HIV and AUD

Device-Orientation Effects on Multiple-Bit Upset in 65-nm SRAMs

Heavy ion irradiations have been performed: a) SEU varies little with angle of ion incidence b) MBU depend on the device orientation. The MBU response depends on the well orientation of the device. MRED simulation of an omni-directional GEO environment shows the MBU response to be a combination of response from different orientations. Testing and simulation must account for multiple orientations

Distinct genetic control of parasite elimination, dissemination, and disease after Leishmania major infection

Elimination of pathogens is the basis of host resistance to infections; however, relationship between persisting pathogens and disease has not been clarified. Leishmania major infection in mice is an important model of host–pathogen relationship. Infected BALB/c mice exhibit high parasite numbers in lymph nodes and spleens, and a chronic disease with skin lesions, splenomegaly, and hepatomegaly, increased serum IgE levels and cytokine imbalance. Although numerous gene loci affecting these disease symptoms have been reported, genes controlling parasites’ elimination or dissemination have never been mapped. We therefore compared genetics of the clinical and immunologic symptomatology with parasite load in (BALB/c × CcS-11) F2 hybrids and mapped five loci, two of which control parasite elimination or dissemination. Lmr5 influences parasite loads in spleens (and skin lesions, splenomegaly, and serum IgE, IL-4, and IFNγ levels), and Lmr20 determines parasite numbers in draining lymph nodes (and serum levels of IgE and IFNγ), but no skin or visceral pathology. Three additional loci do not affect parasite numbers but influence significantly the disease phenotype—Lmr21: skin lesions and IFNγ levels, Lmr22: IL-4 levels, Lmr23: IFNγ levels, indicating that development of L. major-caused disease includes critical regulations additional to control of parasite spread