Imexon activates an intrinsic apoptosis pathway in RPMI8226 myeloma cells

Imexon is a new antitumor agent with high activity in multiple myeloma. This drug induces apoptosis, oxidative stress and mitochondrial alterations. However, it was unknown whether imexon activates an intrinsic apoptotic pathway that is associated with activation of caspase-9 or an extrinsic pathway that is induced by receptor-mediated signals such as Fas ligand characterized by caspase-8 activation. In addition, we wanted to investigate the effect of imexon on Bcl-2 family proteins. In RPMI8226 myeloma cells, imexon activated caspase-9 and -3 in a time- and concentration-dependent manner. In contrast, cleavage of procaspase-8 was observed late and only after exposure to very high concentrations of imexon. Confocal microscopy confirmed that caspase-3 is also activated after treatment with imexon. High imexon concentrations activated caspase-3 and -9 at 12 h, while caspase-8 activation occurred only at 48 h. Imexon cytotoxicity was unchanged in three RPMI8226 cell lines with different levels (low, medium and high) of FAS expression. Similarly, the levels of Bcl-2, Bax and Bcl-xL were unchanged in imexon-treated cells. However, Bcl-xL was translocated to the mitochondria. These data suggest that imexon-induced oxidation activates the intrinsic or mitochondrial pathway of apoptosis, involving cytochrome release and activation of caspase-9 and -3.     

Pharmacokinetics and electrocardiographic pharmacodynamics of artemether-lumefantrine (Riamet) with concomitant administration of ketoconazole in healthy subjects

AIMS: To evaluate whether the potent CYP3A4 inhibitor ketoconazole has any influence on the pharmacokinetic and electrocardiographic parameters of the antimalarial co-artemether (artemether-lumefantrine) in healthy subjects. METHODS: Sixteen subjects were randomized in an open-label, two period crossover design study. Subjects received a single dose of co-artemether (day 1) either alone or in combination with multiple oral doses of ketoconazole (400 mg on day 1 followed by 200 mg o.d. for 4 additional days). Serial blood samples were taken and assayed for artemether and its main active metabolite dihydroartemisinin (DHA), and lumefantrine. RESULTS: The pharmacokinetics of artemether, its metabolite DHA, and lumefantrine were influenced by the presence of ketoconazole. AUC(0, infinity ) was increased from 320 to 740 ng ml-1 h (ratio 2.4, 90% CI 2.00, 2.86) for artemether, from 331 to 501 ng ml-1 h (ratio 1.7, 90% CI 1.40, 1.98) for DHA, and from 207 to 333 micro g ml-1 h (ratio 1.7, 90% CI 1.23, 2.21) for lumefantrine in the presence of ketoconazole. Cmax also increased in similar proportions for the three compounds (ratio 2.2 (90% CI 1.78, 2.83), 1.4 (90% CI 1.12, 1.74), and 1.3 (90% CI 0.96, 1.64), respectively). The terminal elimination half-life was increased for artemether (2.5 vs 1.9 h, 90% CI 1.12, 1.72) and DHA (3.1 vs 2.1 h, 90% CI 0.02, 3.36), but remained unchanged for lumefantrine (88 vs 95 h, 90% CI 0.81, 1.04). These increases in exposure to the antimalarial combination were much smaller than observed with food intake (up to 16 fold), and were not associated with increased side-effects or changes in electrocardiographic parameters. The study medications were well tolerated. CONCLUSIONS: The concurrent administration of ketoconazole with co-artemether led to modest increases in artemether, DHA, and lumefantrine exposure in healthy subjects. Dose adjustment of co-artemether is probably unnecessary in falciparum malaria patients when administered in association with ketoconazole or other potent CYP3A4 inhibitors.     

Seroprevalence of low rubella IgG antibody levels among antenatal women in England tested by NHS Blood and Transplant: 2004-2009. Is rubella susceptibility increasing?

Antenatal testing for rubella susceptibility is undertaken to identify women at risk of exposure during pregnancy and to target post-partum immunisation. To evaluate the current rubella control programme and to inform future planning, data on anti-rubella IgG levels in antenatal sera tested by NHS Blood and Transplant were reviewed. The frequency of women with anti-rubella IgG <10 IU/mL increased by 60% over the 6-year study period and rates were significantly higher among younger women. The screening cut-off level of 10 IU/mL, used to identify women at risk, was determined in 1995 on the basis of early epidemiological studies and the correlates for protection now need review to support the appropriate management of a young immunised antenatal population. Ethnic minorities continue to be at increased risk of rubella susceptibility re-inforcing the need to identify and opportunistically immunise these women.     

Genetic diversity of Ascaris in southwestern Uganda

Despite the common occurrence of ascariasis in southwestern Uganda, helminth control in the region has been limited. To gain further insights into the genetic diversity of Ascaris in this area, a parasitological survey in mothers (n=41) and children (n=74) living in two villages, Habutobere and Musezero, was carried out. Adult Ascaris worms were collected from infected individuals by chemo-expulsion using pyrantel pamoate treatment. Genetic diversity within these worms was assessed by inspection of DNA sequence variation in a mitochondrial marker and length polymorphism at microsatellite loci. Overall prevalence of ascariasis was 42.5% in mothers and 30.4% in their children and a total of 98 worms was examined from 18 hosts. Sequence analysis of a portion of the mitochondrial cytochrome c oxidase subunit 1 gene revealed 19 different haplotypes, 13 of which had not been previously encountered. Microsatellite analysis using eight loci provided evidence for high gene flow between worm populations from the two villages but comparing these worms with others obtained in a prior study on Unguja, Zanzibar, confirmed little genetic exchange and mixing of worm populations between the two areas. By adding to our understanding of the genetic diversity of Ascaris in Africa, this study provides useful information for monitoring changes in parasite population structure in the face of ongoing and future control.     

The exposure of infants and children to carbon monoxide from biomass fuels in The Gambia: a measurement and modeling study

Smoke from biomass fuels is a risk factor for pneumonia, the leading cause of child death worldwide. Although particulate matter (PM) is the metric of choice for studying the health effects of biomass smoke, measuring children's PM exposure is difficult. Carbon monoxide (CO), which is easier to measure, can be used as a proxy for PM exposure. We measured the exposure of children ≤ 5 years of age in The Gambia to CO using small, passive, color stain diffusion tubes. We conducted multiple CO measurements on a subset of children to measure day-to-day exposure variability. Usual CO exposure was modeled using a mixed effects model, which also included individual and household level exposure predictors. Mean measured CO exposure for 1181 children (n=2263 measurements) was 1.04 ± 1.46?p.p.m., indicating that the Gambian children in this study on average have a relatively low CO exposure. However, 25% of children had exposures of 1.3?p.p.m. or higher. CO exposure was higher during the rainy months (1.33 ± 1.62?p.p.m.). Burning insect coils, using charcoal, and measurement done in the rainy season were associated with higher exposure. A parsimonious model with fuel, season, and other PM sources as covariates explained 39% of between-child variation in exposure and helped remove within-child variability.     

Implementing patient-reported outcomes assessment in clinical practice: a review of the options and considerations

Purpose

While clinical care is frequently directed at making patients ??feel better,?? patients?? reports on their functioning and well-being (patient-reported outcomes [PROs]) are rarely collected in routine clinical practice. The International Society for Quality of Life Research (ISOQOL) has developed a User??s Guide for Implementing Patient-Reported Outcomes Assessment in Clinical Practice. This paper summarizes the key issues from the User??s Guide.

Methods

Using the literature, an ISOQOL team outlined considerations for using PROs in clinical practice; options for designing the intervention; and strengths, weaknesses, and resource requirements associated with each option.

Results

Implementing routine PRO assessment involves a number of methodological and practical decisions, including (1) identifying the goals for collecting PROs in clinical practice, (2) selecting the patients, setting, and timing of assessments, (3) determining which questionnaire(s) to use, (4) choosing a mode for administering and scoring the questionnaire, (5) designing processes for reporting results, (6) identifying aids to facilitate score interpretation, (7) developing strategies for responding to issues identified by the questionnaires, and (8) evaluating the impact of the PRO intervention on the practice.

Conclusions

Integrating PROs in clinical practice has the potential to enhance patient-centered care. The online version of the User??s Guide will be updated periodically.     

Strategies for genetic association analyses combining unrelated case-control individuals and family trios

In genetic association studies, analyses integrating data or estimates from unrelated case-control individuals and case trios (case offspring and their parents) can increase statistical power to identify disease susceptibility loci. Data on control trios may also be available, but how and when their use is advantageous is less familiar and is described here. In addition, the authors examine assumptions and properties of hybrid analyses combining association estimates from unrelated case-control individuals together with case and control family trios, focusing on low-prevalence disease. One such assumption is absence of population stratification bias (PSB), a potential source of confounding in case-control analyses. For detection of PSB, the authors discuss 4 possible tests that assess equality between individual-level and family-based estimates. Furthermore, a weighted framework is presented, in which estimates from analyses combining unrelated individuals and families (most powerful but subject to PSB) and family-based analyses (robust to PSB) are weighted according to the observed PSB test P value. In contrast to existing hybrid designs that combine individuals and families only if no significant PSB is detected, the weighted framework does not require specification of an arbitrary PSB testing level to establish significance. The statistical methods are evaluated using simulations and applied to a candidate gene study of childhood leukemia (Quebec Childhood Leukemia Study, 1980-2000).     

Impaired production of TNF-α by dendritic cells of older adults leads to a lower CD8+ T cell response against influenza

Seasonal influenza causes more morbidity and mortality in older adults than in young adults, apparently because of a decline in immune function with increasing age, known as immunosenescence. In this study, we compared the capacity of dendritic cells (DCs) from healthy older adults (≥65 years) with DCs from healthy young adults (20-40 years) to initiate a T cell response against influenza. DCs from older adults were impaired in the induction of influenza-specific CD8+ T cells as compared to DCs from young adults, which was demonstrated by a decreased proliferation, an impaired production of IFN-γ and a reduced expression of the degranulation marker CD107a by CD8+ T cells. Importantly, DCs from older adults produced significantly less TNF-α, showed a decreased expression of HLA class I and had a lower maturation state after influenza virus infection. Supplementing TNF-α increased the expression of HLA class I and of maturation markers and enhanced the induction of the influenza-specific CD8+ T cell response. Together, these findings indicate that the impaired influenza-specific CD8+ T cell response in older adults is associated with a reduced production of TNF-α and with a lower DC maturation. We suggest that the production of TNF-α is a determining factor in the DC-mediated CD8+ T cell response against influenza.     

Glycosaminoglycans in the accessory sex glands, testes and seminal plasma of alpaca and ram

The viscous nature of alpaca semen limits its use in cryopreservation and other assisted reproductive technologies. The cause and source of this viscosity is unknown although it has been postulated, but never proven, that glycosaminoglycans (GAGs) secreted by the bulbourethral gland are responsible. The present study investigated the concentration and composition of GAGs in alpaca seminal plasma, testes, bulbourethral gland and prostate gland and compared them to those in the ram to determine the relationship between seminal plasma GAGs and viscosity and to identify the source of seminal plasma GAGs. Alpaca seminal plasma contained more GAGs than ram (P<0.001) and the predominant GAG, keratan sulfate, was correlated with viscosity (P=0.05, R(2)=0.2635). The alpaca bulbourethral gland contained most GAGs compared with prostate or testis (P<0.001). In the ram, the prostate contained most GAGs. These findings suggest that GAGs, particularly keratan sulfate, may be the cause of seminal plasma viscosity in alpacas, and that the seminal plasma GAGs originate from the bulbourethral gland.