Biomedical subjects

J Burhop

Publications and source records attributed to J Burhop.

4 recordsLinked to original sources

PubMed2005

Predictors of C-reactive protein in Tsimane' 2 to 15 year-olds in lowland Bolivia.

Infectious disease is a major global determinant of child morbidity and mortality, and energetic investment in immune defenses (even in the absence of overt disease) is an important life-history variable, with implications for human growth and development. This study uses a biomarker of immune activation (C-reactive protein) to investigate an important aspect of child health among the Tsimane', a relatively isolated Amerindian population in lowland Bolivia. Our objectives are twofold: 1) to describe the distribution of CRP by age and gender in a cross-sectional sample of 536 2-15-year-olds; and 2) to explore multiple measures of pathogen exposure, economic resources, and acculturation as predictors of increased CRP. The median blood-spot CRP concentration was 0.73 mg/l, with 12.9% of the sample having concentrations greater than 5 mg/L, indicating a relatively high degree of immune activation in this population. Age was the strongest predictor of CRP, with the highest concentrations found among younger individuals. Increased CRP was also associated with higher pathogen exposure, lower household economic resources, and increased maternal education and literacy. The measurement of CRP offers a direct, objective indicator of immune activation, and provides insights into a potentially important pathway through which environmental quality may shape child growth and health.

Acculturation↗

PubMed2001

Effects of a cardiomyopathy-causing troponin t mutation on thin filament function and structure.

Familial hypertrophic cardiomyopathy (FHC) is caused by missense or premature truncation mutations in proteins of the cardiac contractile apparatus. Mutant proteins are incorporated into the thin filament or thick filament and eventually produce cardiomyopathy. However, it has been unclear how the several, genetically identified defects in protein structure translate into impaired protein and muscle function. We have studied the basis of FHC caused by premature truncation of the most frequently implicated thin filament target, troponin T. Electron microscope observations showed that the thin filament undergoes normal structural changes in response to Ca(2+) binding. On the other hand, solution studies showed that the mutation alters and destabilizes troponin binding to the thin filament to different extents in different regulatory states, thereby affecting the transitions among states that regulate myosin binding and muscle contraction. Development of hypertrophic cardiomyopathy can thus be traced to a defect in the primary mechanism controlling cardiac contraction, switching between different conformations of the thin filament.

Actins↗

PubMed1998

A partial matching theory of the mirror effect in immediate probed recognition.

A set of experiments on immediate probed recognition of digit triples is reported in which the variables were list length (five, six, seven, or eight triples), the probability that a probe was old (.33, .5, or .67), and whether the digit triples were presented with an auditory component or articulatory suppression. Previous work had suggested that the false alarm (FA) rate in this paradigm was lower when auditory information was available than when it was not; this observation had led to the development of the partial matching theory of immediate probed recognition, according to which FAs could arise not only as a result of unlucky guesses but also when new probes shared a first digit in common with a partially retained target triple. It was argued that partial memory representations were less likely following auditory presentation than following articulatory suppression. Partial matching theory is contrasted with the rational response theory, according to which all FAs are unlucky guesses; partial matching theory gave a better account of the present experimental data than did rational response theory. However, a logical relationship between the two theories was suggested, a consequence of which was that rational response theory could be modified to include partial matching in such a way as to account for mirror effects, not only in unusually difficult immediate probed recognition tasks, but also in the more commonly studied mixed test list paradigm involving words of high or low frequency.

Adult↗

PubMed1992

Laparoscopic highly selective vagotomy: technique and case report.

As the advantages of minimally invasive surgical techniques become more apparent, new applications are being identified. Here we describe the technique and our initial experience with laparoscopic highly selective vagotomy. The ability to perform this effective antiulcer operation laparoscopically with minimal resultant pain, reduced hospital time, less cost, and diminished morbidity may make surgical therapy a more attractive option in the management of peptic ulcer disease.

Duodenal Ulcer↗