Biomedical subjects

James Evans

Publications and source records attributed to James Evans.

6 recordsLinked to original sources

PubMed2003

Multiple coexistent dysraphic pathologies.

INTRODUCTION: Four distinct dysraphic anomalies were observed in a single child. While combinations of such anomalies are well recognised, quadruple dysraphic pathology, nevertheless, is extremely uncommon. To our knowledge, no previous cases have been reported in the literature. CASE REPORT: We present the management of a child with a concurrent segmental meningocele, a type-1 split cord malformation (SCM) associated with hemivertebrae, lipomyelomeningoceles in each hemicord of the SCM and a terminal myelocystocele, and we review the literature on potential mechanisms of dysmorphogenesis. DISCUSSION: Existing embryologic hypotheses for the dysraphic spectrum lack experimental evidence and studies in animal models. This case challenges the existing hypotheses and illustrates our incomplete understanding of human terminal spinal cord embryogenesis. Further studies on the morphogenetic basis for these anomalies are required.

Abnormalities, Multiple↗

PubMed2003

Health services for homeless adolescents.

This prospective review was designed to determine the effectiveness of a broad-spectrum health intervention program for homeless and runaway youth. Diagnosis, treatment, and counseling for drug use, sexually transmitted diseases (STDs), and other health issues were provided to all new admissions to a residential care facility during a 7(1/2)-year enrollment. Education was continued during a minimum follow-up period of 9 months based on the program entitled Bright Futures, previously developed and published by the National Center for Education in Maternal and Child Health. Fifty-four percent of the study residents had STDs on admission, and 9% developed new STDs after completing therapy and undergoing counseling. Drug dependence was reduced from 47% to 4%, and 46% achieved full-time or part-time employment. Sixty-three percent completed hepatitis B immunization with the 3-dose series. This experience suggests that an organized program of interventions in a residential care facility for homeless teenagers can significantly reduce drug dependence and STDs.

Adolescent↗

PubMed2003

Branched fatty acids in dairy and beef products markedly enhance alpha-methylacyl-CoA racemase expression in prostate cancer cells in vitro.

An enzyme previously identified as alpha-methylacyl-CoA racemase (AMACR) is overexpressed in high-grade prostatic intraepithelial neoplasia and in a majority (60-100%) of prostate cancers (CaPs) as compared with normal and benign hyperplastic lesions of the prostate, where it is minimally expressed. This enzyme is required for the beta-oxidation of branched-chain fatty acids, which include phytanic acid and its alpha-oxidation product, pristanic acid. Interestingly, there is an established correlation between CaP risk and the consumption of dairy and beef products, which also contain marked quantities of these two phytols. In this context, it has also been reported that sex steroids influence lipogenesis through the induction of fatty acid synthase in CaP-derived cell lines and CaP tissues. These findings indicate a potential role for AMACR and the possible influence of sex steroids in both the early development and subsequent progression of CaP. Despite the recent interest in AMACR as a histological marker for CaP, little is known about the regulation of this enzyme and its role in CaP development. To identify potential AMACR-regulating factors, we treated LNCaP cells (an androgen-responsive CaP-derived cell line) and NPrEC cells (a normal prostate basal epithelial cell line) with increasing concentrations of pristanic acid, phytanic acid, 5alpha-dihydrotestosterone, and 17beta-estradiol. Neither the biologically potent androgen 5alpha-dihydrotestosterone nor 17beta-estradiol had any apparent effect on AMACR expression at the protein or transcriptional levels in either cell line. Conversely, pristanic acid and, to a much lesser extent, phytanic acid markedly increased AMACR protein levels selectively in the LNCaP cell line, but not the NPrEC cell line. However, no change was measured at the transcriptional level in either cell line. AMACR is therefore significantly increased at the protein level in CaP cells, through what appears to be the stabilizing effect of the same fatty acids that are present at appreciable concentrations in beef and dairy products, which have been associated with CaP risk. Our findings therefore provide a link between the consumption of dietary fatty acids and the enhanced expression of AMACR, an enzyme that may play an important role in genesis and progression of CaP.

5-alpha-Dihydroprogesterone↗

PubMed2002

Improved molecular identification of Thermoactinomyces spp. associated with mushroom worker's lung by 16S rDNA sequence typing.

Mushroom worker's lung (MWL) is a hypersensitivity pneumonitis or allergic alveolitis caused by a type III IgG-mediated immunopathogenic inflammatory reaction in the host due to the inhalation of several thermophilic organisms, including Thermoactinomyces spp. It is difficult to distinguish phenotypically the eight species of this genus; therefore, this study sought to develop an improved molecular means of identifying Thermoactinomyces spp. associated with MWL by partial 16S rDNA PCR amplification and direct sequencing. Hypervariable regions within the 16S rRNA gene, which could be employed as signature sequences of the eight individual species, were identified and employed with highly conserved flanking primers to allow initial PCR amplification, before direct DNA sequencing of the 16S rDNA amplicons. A novel 24-mer 16S rDNA oligonucleotide upstream primer was designed from in silico alignments of all Thermoactinomyces spp. and was employed in combination with downstream (reverse) 16S rDNA primers. This permitted the successful identification of all four isolates associated with mushroom workers' lung. The method may be useful in the identification of Thermoactinomyces spp. associated with allergic alveolitis or pneumonitis associated with occupational exposure in agricultural and horticultural environments.

Agricultural Workers' Diseases↗

PubMed2002

Genetics in primary care: a USA faculty development initiative.

The Genetics in Primary Care (GPC) project is a USA national faculty development initiative with the goal of enhancing the training of medical students and primary care residents by developing primary care faculty expertise in genetics. Educational strategies were developed for the project by an executive committee with input from an advisory committee, comprising individuals with primary care, medical education and genetics expertise. These committees identified the key issues in genetics education for primary care as (1) considering inherited disease in the differential diagnosis of common disorders; (2) using appropriate counseling strategies for genetic testing and diagnosis, and (3) understanding the implications of a genetic diagnosis for family members. The group emphasized the importance of a primary care perspective, which suggests that the clinical utility of genetic information is greatest when it has the potential to improve health outcomes. The group also noted that clinical practice already incorporates the use of family history information, providing a basis for discussing the application of genetic concepts in primary care. Genetics and primary care experts agreed that educational efforts will be most successful if they are integrated into existing primary care teaching programs, and use a case-based teaching format that incorporates both clinical and social dimensions of genetic disorders. Three core clinical skills were identified: (1) interpreting family history; (2) recognizing the variable clinical utility of genetic information, and (3) acquiring cultural competency. Three areas of potential controversy were identified as well: (1) the role of nondirective counseling versus shared decision-making in discussions of genetic testing; (2) the intrinsic value of genetic information when it does not influence health outcomes, and (3) indications for a genetics referral. The project provides an opportunity for ongoing discussion about these important issues.

Journal Article↗

PubMed2002

Retinoid quantification by HPLC/MS(n).

UNLABELLED: Retinoic acid (RA) mediates most of the biological effects of vitamin A that are essential for vertebrate survival. It acts through binding to receptors that belong to the nuclear receptor transcription factor superfamily (Mangelsdorf et al. 1994). It is also a highly potent vertebrate teratogen. To determine the function and effects of endogenous and exogenous RA, it is important to have a highly specific, sensitive, accurate, and precise analytical procedure. Current analyses of RA and other retinoids are labor intensive, of poor sensitivity, have limited specificity, or require compatibility with RA reporter cell lines (Chen et al. 1995. BIOCHEM: Pharmacol. 50: 1257-1264; Creech Kraft et al. 1994. BIOCHEM: J. 301: 111-119; Lanvers et al. 1996. J. Chromatogr. B Biomed. Appl. 685: 233-240; Maden et al. 1998. DEVELOPMENT: 125: 4133-4144; Wagner et al. 1992. DEVELOPMENT: 116: 55-66). This paper describes an HPLC/mass spectrometry/mass spectrometry product ion scan (HPLC/MS(n)) procedure for the analysis of retinoids that employs atmospheric pressure chemical ionization MS. The retinoids are separated by normal-phase column chromatography with a linear hexane-isopropanol-dioxane gradient. Each retinoid is detected by a unique series of MS(n) functions set at optimal collision-induced dissociation energy (30% to 32%) for all MS(n) steps. The scan events are divided into three segments, based on HPLC elution order, to maximize the mass spectrometer duty cycle. The all-trans, 9-cis, and 13-cis RA isomers are separated, if desired, by an isocratic hexane-dioxane-isopropanol mobile phase. This paper describes an HPLC/MS(n) procedure possessing high sensitivity and specificity for retinoids.

Animals↗