Phenotypic effects of overexpression of the MMAC1 gene in prostate epithelial cells

The prostate cancer cell lines PC3 and LNCaP have been shown to lack expression of the tumour suppressor gene MMAC1/PTEN, in contrast to the immortalized non-tumorigenic epithelial lines PNT1a and PNT2. We have measured the effects of reintroduction of wild type (wt) and mutant MMAC1 genes on to these genetic backgrounds, using gene constructs expressing either wt MMAC1 or various mutants deficient in the dual specificity phosphatase domain of the protein. Over-expression of wild type PTEN protein induced cell shrinkage and rounding, but did not result in increased levels of classical apoptosis. Permanently transfected lines containing the MMAC1 gene could only be obtained from the PNT cells, as PTEN expression resulted in rapid loss of both tumour lines. In contrast, mutation of the phosphatase domain resulted in partial attenuation of the phenotypic effects of MMAC1 after transient transfection, and also allowed the derivation of permanent tumour cell lines containing the mutated MMAC1 gene. The results suggest that re-expression of wt PTEN is incompatible with survival of human prostate cancer cells in vitro, and that the full biological activity of this common tumour suppressor requires functions additional to the established protein and lipid phosphatase activities in epithelial systems. © 2000 Cancer Research Campaig

In vitro modelling of epithelial and stromal interactions in non-malignant and malignant prostates

To study the effects of stromal epithelial cell interactions on prostate cancer metastasis, we have used primary human prostatic stromal cells derived from malignant and non-malignant tissues and established epithelial cell lines from normal (PNT1a and PNT2-C2) and tumour (PC-3, DU145 and LNCaP) origins. The effects of stromal cells on epithelial cell growth were studied in direct and indirect (using culture inserts) co-culture and by exposure to stromal cell-conditioned medium (assessed by MTT assay). The influence of stromal cells on epithelial cell invasion was measured using matrigel invasion chambers and on epithelial cell motility using time lapse microscopy. Results indicated that epithelial cell line growth was similarly unaffected or inhibited by stromal cells derived from malignant (n = 8) or non-malignant tissue (n = 8). In contrast, PNT2-C2 and PC-3 cells were found to be the least and the most invasive and motile epithelia respectively. Stromal cultures enhanced the invasion of both epithelial cells, but no differences were observed between the use of malignant and non-malignant tissues. All stromal cultures modestly stimulated PNT2-C2 motility but displayed a greater stimulation of PC-3 cell motility, while stromal cells derived from malignant tissue stimulated PNT2-C2 and PC-3 cell motility more than stromal cultures from non-malignant tissues. © 2000 Cancer Research Campaig

Incidence and clinical characteristics of group A rotavirus infections among children admitted to hospital in Kilifi, Kenya

Background Rotavirus, predominantly of group A, is a major cause of severe diarrhoea worldwide, with the greatest burden falling on young children living in less-developed countries. Vaccines directed against this virus have shown promise in recent trials, and are undergoing effectiveness evaluation in sub-Saharan Africa. In this region limited childhood data are available on the incidence and clinical characteristics of severe group A rotavirus disease. Advocacy for vaccine intervention and interpretation of effectiveness following implementation will benefit from accurate base-line estimates of the incidence and severity of rotavirus paediatric admissions in relevant populations. The study objective was to accurately define the incidence and severity of group A rotavirus disease in a resource-poor setting necessary to make informed decisions on the need for vaccine prevention. Methods and Findings Between 2002 and 2004 we conducted prospective surveillance for group A rotavirus infection at Kilifi District Hospital in coastal Kenya. Children < 13 y of age were eligible as "cases" if admitted with diarrhoea, and "controls" if admitted without diarrhoea. We calculated the incidence of hospital admission with group A rotavirus using data from a demographic surveillance study of 220,000 people in Kilifi District. Of 15,347 childhood admissions 3,296 (22%) had diarrhoea, 2,039 were tested for group A rotavirus antigen and, of these, 588 (29%) were positive. 372 (63%) rotavirus-positive cases were infants. Of 620 controls 19 (3.1%, 95% confidence interval [CI] 1.9–4.7) were rotavirus positive. The annual incidence (per 100,000 children) of rotavirus-positive admissions was 1,431 (95% CI 1,275–1,600) in infants and 478 (437–521) in under-5-y-olds, and highest proximal to the hospital. Compared to children with rotavirus-negative diarrhoea, rotavirus-positive cases were less likely to have coexisting illnesses and more likely to have acidosis (46% versus 17%) and severe electrolyte imbalance except hyponatraemia. In-hospital case fatality was 2% among rotavirus-positive and 9% among rotavirus-negative children. Conclusions In Kilifi > 2% of children are admitted to hospital with group A rotavirus diarrhoea in the first 5 y of life. This translates into over 28,000 vaccine-preventable hospitalisations per year across Kenya, and is likely to be a considerable underestimate. Group A rotavirus diarrhoea is associated with acute life-threatening metabolic derangement in otherwise healthy children. Although mortality is low in this clinical research setting this may not be generally true in African hospitals lacking rapid and appropriate management

Injection of photoelectrons into dense argon gas

The injection of photoelectrons in a gaseous or liquid sample is a widespread technique to produce a cold plasma in a weakly--ionized system in order to study the transport properties of electrons in a dense gas or liquid. We report here the experimental results of photoelectron injection into dense argon gas at the temperatureT=142.6 K as a function of the externally applied electric field and gas density. We show that the experimental data can be interpreted in terms of the so called Young-Bradbury model only if multiple scattering effects due to the dense environment are taken into account when computing the scattering properties and the energetics of the electrons.Comment: 18 pages, 10 figures, figure nr. 10 has been redrawn, to be submitted to Plasma Sources Science and Technolog

WHO guidelines on fluid resuscitation in children: missing the FEAST data.

The World Health Organization recommendations on management of common childhood illnesses affect the lives of millions of children admitted to hospital worldwide. Its latest guidelines,1 released in May 2013, continue to recommend rapid fluid resuscitation for septic shock, even though the only large controlled trial of this treatment (Fluid Expansion as a Supportive Treatment (FEAST) found that it increased the risk of death in African children.2 A subsequent systematic review of bolus resuscitation in children with shock resulting from severe infection also did not support its use.3 Failure to take this evidence into account is not consistent with WHO’s commitment to systematically and transparently assess evidence using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) process when producing guidelines and could endanger the lives of children

Aldehyde dehydrogenases and prostate cancer: Shedding light on isoform distribution to reveal druggable target

Prostate cancer represents the most common malignancy diagnosed in men, and is the second-leading cause of cancer death in this population. In spite of dedicated efforts, the current therapies are rarely curative, requiring the development of novel approaches based on innovative molecular targets. In this work, we validated aldehyde dehydrogenase 1A1 and 1A3 isoform expressions in different prostatic tissue-derived cell lines (normal, benign and malignant) and patient-derived primary prostate tumor epithelial cells, demonstrating their potential for therapeutic intervention using a small library of aldehyde dehydrogenase inhibitors. Compound 3b, 6-(4-fluorophenyl)-2-phenylimidazo [1,2-a]pyridine exhibited not only antiproliferative activity in the nanomolar range against the P4E6 cell line, derived from localized prostate cancer, and PC3 cell lines, derived from prostate cancer bone metastasis, but also inhibitory efficacy against PC3 colony-forming efficiency. Considering its concomitant reduced activity against normal prostate cells, 3b has the potential as a lead compound to treat prostate cancer by means of a still untapped molecular target