Vitamin A and its derivatives in experimental photocarcinogenesis: preventive effects and relevance to humans.

The 1925 classical observation that vitamin A deficiency leads to squamous metaplasia and epithelial keratinization, coupled with the later finding that excess vitamin A inhibits keratinization of chick embryo skin, set the foundation for the potential therapeutic use of retinoids in cutaneous conditions of keratinization. Significant progress has since been made understanding the molecular biology, biochemistry, pharmacology, and toxicology of vitamin A and its derivatives, collectively named retinoids. Natural and synthetic retinoids are now routinely used to treat acne, psoriasis, skin keratinization disorders, and photodamage.

Use of topical tretinoin and the development of noncutaneous adverse events: evidence from a systematic review of the literature.

Background: Topical retinoids have been in clinical use for the treatment of chronic skin conditions, including acne, photodamage, and psoriasis, for 30 years.

Objective: A systematic literature review was conducted to assess the incidence of noncutaneous adverse events (AE) among patients treated with topical retinoids with a focus on topical tretinoin studies reported before the Veterans Affairs Topical Tretinoin Chemoprevention trial.

Methods: Electronic literature searches were conducted in Embase and MEDLINE for literature reporting development of nonteratogenic, noncutaneous AE among patients treated with topical retinoids published through September 2008.

The double jeopardy of clustered measurement and cluster randomisation.

suggest that double clustering might explain the negative results of some cluster randomised trials and describe some strategies for avoiding the problem

A randomized breast-feeding promotion intervention did not reduce child obesity in Belarus.

The evidence that breast-feeding protects against obesity is based on observational studies, with potential for confounding and selection bias. This article summarizes a previously published study in which we assessed whether an intervention designed to promote exclusive and prolonged breast-feeding affects children's height, weight, adiposity, and blood pressure (BP) at age 6.5 y.

Independent effect of depression and anxiety on chronic obstructive pulmonary disease exacerbations and hospitalizations.

Rationale: Depression and anxiety are significant comorbid and potentially modifiable conditions in chronic obstructive pulmonary disease (COPD), but their effects on exacerbations are not clear.

Objectives: To investigate the independent effect of depression and anxiety on the risk of COPD exacerbations and hospitalizations.

Methods: A multicenter prospective cohort study in 491 patients with stable COPD in China.

Breastfeeding and child cognitive development: new evidence from a large randomized trial.

Context: The evidence that breastfeeding improves cognitive development is based almost entirely on observational studies and is thus prone to confounding by subtle behavioral differences in the breastfeeding mother's behavior or her interaction with the infant.

Objective: To assess whether prolonged and exclusive breastfeeding improves children's cognitive ability at age 6.5 years.

LIGR, a protease-activated receptor-2-derived peptide, enhances skin pigmentation without inducing inflammatory processes.

The protease-activated receptor-2 (PAR-2) is a seven transmembrane G-protein-coupled receptor that could be activated by serine protease cleavage or by synthetic peptide agonists. We showed earlier that activation of PAR-2 with Ser-Leu-Ile-Gly-Arg-Leu-NH(2) (SLIGRL), a known PAR-2 activating peptide, induces keratinocyte phagocytosis and increases skin pigmentation, indicating that PAR-2 regulates pigmentation by controlling phagocytosis of melanosomes. Here, we show that Leu-Ile-Gly-Arg-NH(2) (LIGR) can also induce skin pigmentation.

Effects of prolonged and exclusive breastfeeding on child height, weight, adiposity, and blood pressure at age 6.5 y: evidence from a large randomized trial.

Background: The evidence that breastfeeding protects against obesity and a variety of chronic diseases comes almost entirely from observational studies, which have a potential for bias due to confounding, selection bias, and selective publication.

Objective: We assessed whether an intervention designed to promote exclusive and prolonged breastfeeding affects children's height, weight, adiposity, and blood pressure at age 6.5 y.

Iatrogenic risk factors for cytomegalovirus retinitis.

Background: To determine the iatrogenic risk factors for cytomegalovirus (CMV) retinitis in patients with the acquired immunodeficiency syndrome (AIDS).

Methods: The case-control study included 120 patients with CMV retinitis and 159 patients without CMV retinitis, all of whom had AIDS and CD4 counts less than 50 cells/microL at the time of diagnosis of retinitis or at the defined corresponding date in the controls. Iatrogenic risk factors studied were corticosteroid use, treatment with chemotherapy, treatment with radiotherapy, and blood transfusions.

Laboratory-based risk factors for cytomegalovirus retinitis.

Background: Very few studies have investigated risk factors for cytomegalovirus (CMV) retinitis. Identifying these risk factors will have many benefits, including helping establish screening regimens, examination frequency regimens, and targeted prophylaxis with oral therapy with valganciclovir or other anti-CMV agents. The purpose of this study was to determine the laboratory-based risk factors for CMV retinitis in patients with AIDS.

Inhibitory effect of topical applications of nondenatured soymilk on the formation and growth of UVB-induced skin tumors.

Treatment of female SKH-1 hairless mice with ultraviolet B light twice a week for 20 weeks resulted in a population of tumor-free mice with a high risk of developing skin tumors during the next several months in the absence of additional UVB treatment (high-risk mice). Topical applications of nondenatured soymilk but not heat-denatured soymilk once a day, 5 days a week to these high-risk mice inhibited the formation and growth of skin tumors. Similar topical applications of soybean trypsin inhibitor or Bowman-Birk inhibitor also inhibited the formation and growth of skin tumors, but these agents were less active than nondenatured soymilk.

Clinical risk factors for cytomegalovirus retinitis in patients with AIDS.

Purpose: To determine the clinical risk factors for cytomegalovirus (CMV) retinitis in patients with AIDS.

Design: A case-control study.

Participants: The study included 120 patients in whom CMV retinitis had been diagnosed from 1990 through 1999 (cases) and 159 patients without CMV retinitis from the same period (controls).

Effectiveness of intensive rehabilitation on functional ability and quality of life after first total knee arthroplasty: A single-blind randomized controlled trial.

Objective: To evaluate the effectiveness of a new intensive functional rehabilitation (IFR) program on functional ability and quality of life (QOL) in persons who underwent a first total knee arthroplasty (TKA).

Design: Randomized controlled trial.

Setting: Ambulatory care.

Surgery versus collagen for female stress urinary incontinence: economic assessment in Ontario and Quebec.

Introduction And Objective: The purpose of this study was to evaluate the cost-effectiveness of surgery versus collagen injection to treat female stress urinary incontinence after the failure of initial surgical treatment. The analysis was conducted from the health care system perspectives of Ontario and Quebec.

Materials And Methods: A decision-tree was constructed to compare each of three surgeries (i.

Oral health status and treatment satisfaction with mandibular implant overdentures and conventional dentures: a randomized clinical trial in a senior population.

Purpose: The purpose of this study was to compare elderly patients' satisfaction and oral health-related quality of life with mandibular two-implant overdentures and conventional dentures.

Materials And Methods: Sixty edentulous subjects aged 65 to 75 years were randomly assigned to two groups treated with maxillary conventional dentures and either a mandibular conventional denture (n = 30) or an overdenture supported by two implants with ball retainers (n = 30). Subjects rated their general satisfaction, as well as other features of their dentures (comfort, stability, ability to chew, speech, esthetics, and cleaning ability), prior to treatment and 2 months postdelivery.

Infant growth and health outcomes associated with 3 compared with 6 mo of exclusive breastfeeding.

Background: Opinions and recommendations about the optimal duration of exclusive breastfeeding have been strongly divided, but few published studies have provided direct evidence on the relative risks and benefits of different breastfeeding durations in recipient infants.

Objective: We examined the effects on infant growth and health of 3 compared with 6 mo of exclusive breastfeeding.

Design: We conducted an observational cohort study nested within a large randomized trial in Belarus by comparing 2862 infants exclusively breastfed for 3 mo (with continued mixed breastfeeding through >/= 6 mo) with 621 infants who were exclusively breastfed for >/= 6 mo.

A survey of physician efficacy requirements to plan clinical trials.

Purpose: Eliciting physician efficacy requirements for utilizing medical treatments can be a useful means of helping plan a clinical trial. Efficacy requirements were studied for female stress urinary incontinence, where an experimental treatment (collagen injection) was compared to the standard therapy (surgery).

Methods: A self-administered questionnaire was sent to 223 North American urologists, gynecologists, and urogynecologists.

Healthcare utilization by women in a comprehensive managed care population subsequent to diagnosis of a sexually transmitted disease.

Background: Healthcare utilization (HCU) following a sexually transmitted disease (STD) diagnosis is poorly characterized.

Goal: The goal was to quantify HCU for new/recurrent STDs and other relevant Ob-Gyn and mental health problems in the 18 months subsequent to an STD diagnosis.

Study Design: We compared HCU between a group of females aged 18 to 45 years who were Kaiser Permanente Medical Program members with a diagnosed STD (n = 1,205) and a medical center- and age group-matched sample of women seen for a non-STD diagnosis in the same time period (n = 4820), with controlling where appropriate for age, medical center, and chronic disease status.

Breastfeeding and infant growth: biology or bias?

Background: Available evidence suggests that prolonged and exclusive breastfeeding is associated with lower infant weight and length by 6 to 12 months of age. This evidence, however, is based on observational studies, which are unable to separate the effects of feeding mode per se from selection bias, reverse causality, and the confounding effects of maternal attitudinal factors.

Design/methods: A cluster-randomized trial in the Republic of Belarus of a breastfeeding promotion intervention modeled on the World Health Organization (WHO)/UNICEF Baby-Friendly Hospital Initiative versus control (then current) infant feeding practices.

Medical care capacity for influenza outbreaks, Los Angeles.

In December 1997, media reported hospital overcrowding and "the worst [flu epidemic] in the past two decades" in Los Angeles County (LAC). We found that rates of pneumonia and influenza deaths, hospitalizations, and claims were substantially higher for the 1997-98 influenza season than the previous six seasons. Hours of emergency medical services (EMS) diversion (when emergency departments could not receive incoming patients) peaked during the influenza seasons studied; the number of EMS diversion hours per season also increased during the seasons 1993-94 to 1997-98, suggesting a decrease in medical care capacity during influenza seasons.

Effectiveness of WBC reduction in neonates: what is the evidence of benefit?

Background: The presence of WBCs in RBCs is thought to be associated with a number of significant adverse effects in recipients. In adults, WBC reduction has been shown to reduce the frequency of HLA alloimmunization, CMV and HTLV infections, and febrile nonhemolytic transfusion reactions. However, neonates are unique, given that they have an immature immune system and are frequently transfused with RBCs.