Arsenic-induced enhancement of ultraviolet radiation carcinogenesis in mouse skin: a dose-response study.

The present study was designed to establish the form of the dose-response relationship for dietary sodium arsenite as a co-carcinogen with ultraviolet radiation (UVR) in a mouse skin model. Hairless mice (strain Skh1) were fed sodium arsenite continuously in drinking water starting at 21 days of age at concentrations of 0.0, 1.

The action of a dietary retinoid on gene expression and cancer induction in electron-irradiated rat skin.

Current models of radiation carcinogenesis generally assume that the DNA is damaged in a variety of ways by the radiation and that subsequent cell divisions contribute to the conversion of the damage to heritable mutations. Cancer may seem complex and intractable, but its complexity provides multiple opportunities for preventive interventions. Mitotic inhibitors are among the strongest cancer preventive agents, not only slowing the growth rate of preneoplasias but also increasing the fidelity of DNA repair processes.

Drug-induced reversible lymphoid dyscrasia: a clonal lymphomatoid dermatitis of memory and activated T cells.

Certain systemic conditions predispose patients to excessive lymphocyte responses to immune-perturbing drugs, which may progress to malignant lymphoma. Many pathologists and clinicians believe that differentiation of pseudolymphoma from cutaneous T cell lymphoma (CTCL) can be reliably made through phenotypic and molecular analysis. We encountered 15 cases of atypical cutaneous T-cell lymphoid hyperplasia in the setting of drug therapy.

Arsenite cocarcinogenesis: an animal model derived from genetic toxicology studies.

Although epidemiologic evidence shows an association between inorganic arsenic in drinking water and increased risk of skin, lung, and bladder cancers, no animal model for arsenic carcinogenesis has been successful. This lack has hindered mechanistic studies of arsenic carcinogenesis. Previously, we and others found that low concentrations (< or =5 microm) of arsenite (the likely environmental carcinogen), which are not mutagenic, can enhance the mutagenicity of other agents, including ultraviolet radiation (UVR) and alkylating agents.

Pityriasis lichenoides: a clonal T-cell lymphoproliferative disorder.

Pityriasis lichenoides (PL) is a papulosquamous disorder often considered a form of reactive dermatosis and classified with small plaque parapsoriasis (digitate dermatosis). However, some patients with PL have developed large plaque parapsoriasis (LPP) and mycosis fungoides (MF), and lymphoid atypia and T-cell clonality have been reported in lesions of PL. We set out to explore the possibility that PL is a form of T-cell dyscrasia.

An urban epidemic--an audit of an inner city young persons' clinic.

In 1996 a young persons' clinic was set up at the Archway Sexual Health Clinic. A retrospective case note review of all attendees for 7 months in 1999 was performed to assess the demography and incidence of sexually transmitted infections (STIs) amongst attenders of the clinic. There were 567 attendances, comprising 364 individuals (331 women and 33 men).

Fibroma induction in rat skin following single or multiple doses of 1.0 GeV/nucleon 56Fe ions from the Brookhaven Alternating Gradient Synchrotron (AGS).

Rat skin was exposed to the plateau region of the 1.0 GeV/nucleon 56Fe beam at the Brookhaven AGS. Rats were irradiated or not with single of split doses of 56Fe or argon; some 56Fe-exposed rats were fed 250 ppm retinyl acetate continuously in the lab chow beginning 1 week before irradiation.

Africans in London continue to present with advanced HIV disease in the era of highly active antiretroviral therapy.

Our findings show that despite the numerous advances in the management of HIV disease, this has not resulted in earlier presentation in Africans or non-Africans. African patients are still presenting with significantly more advanced disease than non-Africans, and are more likely to have AIDS at presentation in 1998-1999 than in 1982-1995. An urgent need exists to identify the factors associated with delayed presentation, both to optimize clinical outcomes and reduce the possibility of onward transmission.

Arsenite is a cocarcinogen with solar ultraviolet radiation for mouse skin: an animal model for arsenic carcinogenesis.

Although epidemiological evidence shows an association between arsenic in drinking water and increased risk of skin, lung, and bladder cancers, arsenic compounds are not animal carcinogens. The lack of animal models has hindered mechanistic studies of arsenic carcinogenesis. Previously, this laboratory found that low concentrations of arsenite (the likely environmental carcinogen) which are not mutagenic can enhance the mutagenicity of other agents, including ultraviolet radiation (UVR).

Lupus profundus, indeterminate lymphocytic lobular panniculitis and subcutaneous T-cell lymphoma: a spectrum of subcuticular T-cell lymphoid dyscrasia.

Introduction: The diagnosis and classification of lymphocytic lobular panniculitis (LLP) has historically proven to be a difficult challenge. We encountered 32 cases of primary LLP which could be categorized as: 1) lupus erythematosus profundus (LEP) (19 patients); 2) an indeterminate group termed indeterminate lymphocytic lobular panniculitis (ILLP) (6 patients); and 3) subcutaneous T-cell lymphoma (SCTCL) (7 patients).

Objective: We attempted to better define the subtypes of LLP by morphologic, phenotypic and genotypic features and to correlate those features to clinical presentation and outcome.

Sweet's syndrome in the setting of CD34-positive acute myelogenous leukemia treated with granulocyte colony stimulating factor: evidence for a clonal neutrophilic dermatosis.

Background: Sweet's syndrome in the setting of hematologic dyscrasias can be categorized into paraneoplastic-associated SS, drug-induced SS, and SS with leukemia cutis. Apart from those cases demonstrating concomitant leukemic infiltrates, it has been surmised that SS is a reactive phenomenon induced by a specific cytokine milieu.

Methods: The authors present a patient with CD34+ acute myelogenous leukemia (AAML) who developed SS in the setting granulocyte colony stimulating factor (GCSF) therapy.

Sexual maturation and control issues among sexually abused and non-abused anorexia patients.

Objectives: To assess the relative salience of the maintenance of control and the avoidance of sexual maturation as sources of motivation for maintaining pathological eating behaviours among sexually abused anorexic patients.

Design/methods: A two-factor mixed experimental design was employed. Three independent groups (sexually abused anorexics (N = 12); non-abused anorexics (N = 9); non-anorexic/non-abused controls (N = 12)) constituted the between-subjects factor.

Solar ultraviolet radiation and skin damage: an epidemiological study among a Chinese population.

To explore skin damage resulting from solar ultraviolet radiation on Mongoloid people, we investigated 470 healthy people in northeast China. We assessed their skin texture and elastic fibers, number of Langerhans cells, and the incidence of p53 gene mutations. The results showed that solar ultraviolet radiation played a significant role in aging of skin in Chinese people; aging began at 30 y of age (i.

Interaction of nickel with UV-light in the induction of cytogenetic effects in human peripheral lymphocytes.

Chemical interaction is of major concern in the assessment of risk by regulatory agencies. In the present study, treatment of human lymphocytes with NiSO4 (1-100 microM) or UV-light (200, 1000 ergs/mm2) induced micronuclei (MN) in a dose-dependent fashion. Statistical analysis of the interaction factor (IF), showed that combined treatments of Ni(II) (1-100 microM) with UV-light (200, or 1000 ergs/mm2) interacted antagonistically for the induction of MN.

Developmental changes in lung cGMP phosphodiesterase-5 activity, protein, and message.

During transitional circulation, the pulmonary vascular bed undergoes a rapid and profound reduction in both tone and vascular smooth-muscle (VSM) content. 3',5'-Guanylate cyclic monophosphate (cGMP) is a crucial mediator in the regulation of pulmonary vascular resistance (PVR) and VSM proliferation. Hydrolysis of cGMP is achieved predominately by cGMP-specific phosphodiesterases (PDEs).

Oxidative stress suppresses transcription factor activities in stimulated lymphocytes.

Effects of oxidative stress on stimulation-dependent signal transduction, leading to IL-2 expression, were studied. Purified quiescent human blood T lymphocytes were subjected to: (i) acute exposure to hydrogen peroxide; (ii) chronic exposure to hydrogen peroxide; and (iii) acute exposure to ionizing radiation. The cells were then stimulated for 6 h.

Identification of a structural constituent and one possible site of postembryonic formation of a teleost otolithic membrane.

A gelatinous otolithic membrane (OM) couples a single calcified otolith to the sensory epithelium in the bluegill sunfish (Lepomis macrochirus) saccule, one of the otolithic organs in the inner ear. Though the OM is an integral part of the anatomic network of endorgan structures that result in vestibular function in the inner ear, the identity of the proteins that make up this sensory accessory membrane in teleosts, or in any vertebrate, is not fully known. Previously, we identified a cDNA from the sunfish saccular otolithic organ that encoded a new member of the collagen family of structural proteins.

Rare activation of ras oncogenes in radiation induced rat skin tumors.

We examined a large panel of radiation induced rat skin tumors for activation of the H- or K-ras oncogenes. Using oligonucleotide hybridization analysis of tumor DNA we found that only 1 out of 96 tumors tested had an activated K-ras gene, and none of the 78 tumors examined for H-ras mutations were positive. Tumors were induced by high and low LET, and included lesions of various sizes and histologic type.

Identification of key amino acids in a conserved cGMP-binding site of cGMP-binding phosphodiesterases. A putative NKXnD motif for cGMP binding.

cGMP-binding phosphodiesterases contain two kinetically distinct cGMP-binding sites (a and b), and each site contains a conserved N(K/R)XnFX3DE sequence. N276A, K277A, K277R, D289A, and E290A mutants in the N276KX7FX3DE290 sequence of site a (higher affinity site) of bovine cGMP-binding, cGMP-specific phosphodiesterase (cGB-PDE or PDE5A) were expressed in High Five cells and purified. The cGMP-binding affinities of three mutants [K277A (Kd approximately 12 microM), D289A (Kd approximately 24 microM), and N276A (Kd approximately 60 microM)] were decreased in comparison with wild-type enzyme (Kd = 1.

Establishment and evaluation of a statewide drug and alcohol specialist advisory service.

The New South Wales Drug and Alcohol Specialist Advisory Service aims to provide prompt, relevant and reliable advice on the clinical management of drug- and alcohol-related problems to health professionals throughout New South Wales. We gauged the performance of the Service against present indicators by interviewing 120 callers who had contacted the Service during its first two years. Accessibility and the quality of information provided were rated highly.