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Biomedical subjects

J Neville

Publications and source records attributed to J Neville.

11 recordsLinked to original sources
PubMed2001

Crossing over is rarely associated with mitotic intragenic recombination in Schizosaccharomyces pombe.

Chromosomal rearrangements can result from crossing over during ectopic homologous recombination between dispersed repetitive DNA. We have previously shown that meiotic ectopic recombination between artificially dispersed ade6 heteroalleles in the fission yeast Schizosaccharomyces pombe frequently results in chromosomal rearrangements. The same recombination substrates have been studied in mitotic recombination. Ectopic recombination rates in haploids were approximately 1-4 x 10(-6) recombinants per cell generation, similar to allelic recombination rates in diploids. In contrast, ectopic recombination rates in heterozygous diploids were 2.5-70 times lower than allelic recombination or ectopic recombination in haploids. These results suggest that diploid-specific factors inhibit ectopic recombination. Very few crossovers occurred in ade6 mitotic recombination, either allelic or ectopic. Allelic intragenic recombination was associated with 2% crossing over, and ectopic recombination between multiple different pairing partners showed 1-7% crossing over. These results contrast sharply with the 35-65% crossovers associated with meiotic ade6 recombination and suggest either differential control of resolution of recombination intermediates or alternative pathways of recombination in mitosis and meiosis.

Alleles↗
PubMed2000

The Department of Defense laboratory-based global influenza surveillance system.

Military global influenza surveillance began in 1976 as an Air Force program. In 1997, the Department of Defense (DoD) Global Emerging Infections Surveillance and Response System expanded the program to include all services. Also included were local residents in areas where DoD overseas research activities operated. This new, worldwide DoD surveillance infrastructure provides valuable information and can respond quickly to outbreaks. This was demonstrated during the current influenza season when a suspected outbreak was reported in Panama. In less than 3 weeks, specimens were collected, transported, and cultured, and isolates were subtyped and sent to the Centers for Disease Control and Prevention for further studies. This influenza surveillance initiative combines viral isolation, antigenic characterization, and molecular sequencing with clinical and public health management of information. The information obtained is shared with the Centers for Disease Control and Prevention and the World Health Organization and has contributed to important decisions in influenza vaccine composition.

Global Health↗
PubMed1994

Better dermatologic office photography: taking the photograph.

In a previous article we reviewed the questions every medical photographer must ask when looking through the viewfinder, as well as the difference between plastic surgical and dermatologic photography. We conclude by offering a mnemonic for the three views necessary in dermatologic photography: Location, Scan, and Detail, and by suggesting a technique for preadjusting the camera, lens setting, and flash that will guarantee consistent, high-quality clinical photos.

Dermatology↗
PubMed1994

Better dermatologic office photography: getting started.

In an earlier paper, we defined a medical photograph as one that accurately maximizes clinical information while minimizing irrelevant data. This paper expands on this concept, providing specific hints to assist the practitioner in obtaining consistent high-quality clinical photos. We review the important question every medical photographer must ask when looking through the viewfinder as well as the difference between photography for practitioners of plastic surgery and dermatology.

Dermatology↗
PubMed1993

Snapshots versus medical photographs: understanding the difference is your key to better dermatologic office photography.

A medical photograph in contradistinction to a snapshot accurately reproduces and maximizes clinically significant information while minimizing extraneous or irrelevant factors. Obtaining a top-notch medical photograph requires not only proper equipment but also rapid, sophisticated analysis of the clinical situation. Only then can major features including lesional size and distribution and more subtle details such as borders, color, and topography be selectively highlighted. First-rate medical photographs not only enhance the accuracy of diagnosis but also facilitate subsequent assessment of therapeutic efficacy. Furthermore, instruction of students and residents and continuing medical education of practicing clinicians depend on our photographic acumen.

Dermatology↗
PubMed1968

Analysis of T-wave abnormalities associated with myocardial infarction using a theoretic model.

The physiological basis of serial T-wave abnormalities associated with myocardial infarction was studied. After coronary artery ligation in dogs, ventricular functional refractory periods (FRPs) were measured at five to eight epicardial, intramural, and endocardial sites. FRPs measured during acute ischemia shortened an average of 26 msec. FRPs measured 24 to 72 hr after coronary ligation were 24 msec longer at ischemic than at nonischemic sites. Alterations of recovery times were analyzed in terms of a repolarization model which related the form of the action potential downstroke to the form of the T wave of the body surface ECG. Observed FRPs were used to infer action potential duration and T waves were derived. Shortening FRPs in the anterolateral wall of the ventricle increased the amplitude of derived T waves in the X lead and caused T-wave inversion in the Z lead. Prolonging FRPs in the same area caused T-wave inversion in lead X and increased T amplitude in lead Z. The form of derived T waves qualitatively corresponded to serial T-wave abnormalities seen in patients with myocardial infarction.

Action Potentials↗