Post-natal incidence of HIV-1 infection among children in a rural Ugandan population: no evidence for transmission other than mother to child

We conducted a prospective cohort study to determine the post‐natal incidence of and possible transmission routes for HIV‐1 infection in rural Ugandan children. The cohort consisted of the population of a cluster of 15 villages in Masaka District, south‐west Uganda, and was enrolled in 1989–1990 through a demographic and serological survey. During the period 1991–1993 the population was resurveyed annually. A total of 5492 children aged 0–12 years were enrolled; of these, 41 (0.7%) were seropositive infants. A total of 3941 (72%) children were HIV‐negative on enrolment and had at least one follow‐up specimen. During 8596 person‐years of observation only 1 seroconversion was observed, an incidence rate of 0.12 (95% CI 0.00–0.35) per 1000 years of observation. The transmission of HIV was most probably through breast milk. The case corresponds to a rate of 1.1 per 1000 in households with one or more HIV‐positive adults (874 years of observation); no incident case was observed in households with only seronegative adults (6423 years of observation). Thus, HIV infection among children aged 0–12 years in this population is virtually exclusively the result of mother‐to‐child transmission. No infections were observed attributable to parenteral exposure, non‐sexual casual or household contact, or insects.     

National appraisal of dermatology residency training: a Canadian study

OBJECTIVES: To provide the first comprehensive assessment of dermatology residency training in Canada based on the residents' perspective; to examine and elucidate trends in current residents' envisioned career paths and aspirations. DESIGN: A national survey conducted in June 2004. PARTICIPANTS: All Canadian dermatology residents. MAIN OUTCOME MEASURES: Cross-sectional analysis of (1) satisfaction with and importance placed by the trainees on the various curriculum components as measured by a 5-point Likert-type scale and (2) current residents' career and practice plans. RESULTS: One hundred percent of dermatology residents across the country (n = 48) responded to the survey. The greatest discrepancies between ranked importance and corresponding satisfaction were observed for the teaching from faculty (both didactic and clinic based) and for the practice management exposure and training. Residents were most satisfied with dermatopathology education (score, 4.4 of 5.0) and least satisfied with cosmetic dermatology (2.7 of 5.0) and dermoscopy training (2.8 of 5.0). Men indicated more interest than women in academics (71% [n = 12] vs 45% [n = 14]), research (41% [n = 7] vs 16% [n = 5]), and teaching (71% [n = 12] vs 42% [n = 13]), while female residents were more inclined toward pediatric dermatology (42% [n = 13] vs 29% [n = 5]) and cosmetic dermatology (48% [n = 15] vs 29% [n = 5]). An overall trend of decreased interest in academic and hospital-based practice was noted with progression through residency training. CONCLUSIONS: This study provides a current picture of dermatology postgraduate education in Canada from the residents' perspective. Above all, dermatology residents desire more teaching (clinic, didactic, and practice management) and mentorship from their faculty. Recruitment and retention of women in academic dermatology may benefit from early intervention during residency. The data are intended to assist dermatology programs with development, evaluation, and improvement of their curricula and can serve as a reference point to gauge future trends.     

Stressors and antistressors: how do they influence life span in HER-2/neu transgenic mice?

The purpose of this study is to investigate possible influences of different stressors (saline injections, light deprivation and constant light regimen) and geroprotectors (Epitalon and melatonin) on survivals of female HER-2/neu transgenic mice. We propose a semi-parametric model of heterogeneous mortality (frailty model) for the analysis of the experimental data. In this model, we assume that treatment influences parameters of both frailty distribution and baseline hazard. The unique design of the experiments makes it possible to compare the effects on survival produced by different treatments in terms of changes in population heterogeneity and underlying hazard. Parameters of the model help to describe the possible influences of various stressors, geroprotectors, and their dosage on the life span of laboratory animals. The proposed model helps to advance our understanding of the effects--such as debilitation, longevity hormesis and incomplete hormesis--which occur in the population as a result of different treatments.     

Stress resistance declines with age: analysis of data from a survival experiment with Drosophila melanogaster

An approach towards analyzing survivorship data is proposed for the study of changes in stress resistance with age in the population of Drosophila melanogaster. This is based on the model of heterogeneous mortality (frailty model). Results of the data analysis show that observed populations of flies are heterogeneous and the accelerated selection, debilitative effect and changes in individual frailties are the aftermath of stress. These results also reveal that debilitative effect and accelerated selection are much better pronounced in survivals of flies that are stressed at an older age. Mild stress, when applied at both ages, produced a reduction in frailty variance. Stress of greater magnitude produced higher frailty variance in the young-treated flies. Among the old-treated insects, stress of longer duration led to a reduction of both the mean and the variance of frailty distribution. Population of young-treated flies became more heterogeneous, population of old-treated flies became less heterogeneous, and both populations became more robust in average after stress.     

In planta engineering of viral RNA replicons: efficient assembly by recombination of DNA modules delivered by Agrobacterium

We have developed an efficient, versatile, and user-friendly viral engineering and expression system that is based on in planta assembly of functional viral vectors from separate pro-vector modules. With this new system, instead of supplying a plant cell with a complete viral vector as a mature viral particle, an RNA or a linear DNA molecule, we use agrobacteria to deliver various modules that are assembled inside the cell with the help of a site-specific recombinase. The resulting DNA is transcribed, and undesired elements such as recombination sites are spliced out, generating a fully functional RNA replicon. The proposed protocol allows us, by simply treating a plant with a mixture of two or more agrobacteria carrying specific prefabricated modules, to rapidly and inexpensively assemble and test multiple vector/gene combinations, without the need to perform the various engineering steps normally required with alternative protocols. The process described here is very fast (expression requires 3-4 days); it provides very high protein yield (up to 80% of total soluble protein); more than before, it is carried out using in vivo manipulations; it is based on prefabricated genetic modules that can be developed/upgraded independently; and it is inherently scalable.     

Treatment of mycosis fungoides: overview

BACKGROUND: Mycosis fungoides (MF) is the most common clinicopathologic subtype of primary cutaneous T-cell lymphoma. OBJECTIVE: The therapy of MF is highlighted in this overview. RESULTS AND CONCLUSIONS: Skin-directed MF therapies include topical corticosteroids, nitrogen mustard, carmustine (BCNU), topical bexarotene gel, imiquimod cream, radiotherapy, total skin electron beam therapy, and phototherapy. Systemic therapies include extracorporeal photopheresis, interferon, oral bexarotene, denileukin diftitox, monoclonal antibodies and cytokine therapy, and other systemic chemotherapy. Finally, some investigative therapeutic modalities are presented.