Biomedical subjects

B Peterson

Publications and source records attributed to B Peterson.

115 records · Page 7Linked to original sources

PubMedDate not supplied

The kinetics of elastolysis: elastin catabolism during experimentally induced fibrosis.

Lung injury and matrix destruction result in the release into the circulation of desmosine, a product of elastin catabolism. To determine whether measurements of desmosine concentrations in the urine can provide important information about the severity of lung injury, we measured the kinetics of lung elastin catabolism following elastase-induced and fibrotic lung injury in mice. Pancreatic elastase instillation in the lung caused immediate elastin destruction, removing as much as 25% of the lung elastin within the first few hours. Peak concentrations of desmosine peptides appeared in the blood within 1-2 hours, and soluble elastin peptides in the lung and urine followed a similar course with peak levels occurring early and then declining rapidly, approaching control levels by 24 hours. More than half of the desmosine peptides removed from the lung following elastase injury were sequestered by the kidney and then slowly released over a period of several days. Lung histology and morphological measurements indicated that bleomycin, TiO2, and SiO2 instillation resulted in severely fibrotic lungs. However, the lung injuries sustained from these agents resulted in minimal elastin damage, representing less than 0.1% of the total lung elastin catabolized as estimated by desmosine analysis. The rapid accumulation of desmosine in renal tissue and its slow release into the urine keep urine concentrations low and minimize the power of urine desmosine assays for quantifying low level tissue destruction.

Animals↗

PubMedDate not supplied

Determinants of attrition in a natural history study of Alzheimer disease.

The aim of the present study was to identify determinants of attrition in a natural history study of a tertiary care sample of patients with Alzheimer disease (AD) and control subjects. A longitudinal study was performed with 978 patients with AD and 466 control subjects age 50 years and older enrolled at 25 sites of the Consortium to Establish a Registry for Alzheimer's Disease between January 1987 and January 1992; subjects were followed annually for up to 78 months. Both descriptive statistics and polytomous logistic regressions were run to identify determinants of attrition. Of the 1,444 subjects enrolled, 10.5% dropped out after initial evaluation, 31.0% provided at least two waves of data, and 58.4% provided complete follow-up. Inadequate involvement by the site, non-white status, and patient's spouse not enrolled in the study were predictive of dropout; cessation of participation because of death (which may have precluded dropout) predicted continuation in the study. Age, level of education, severity of dementia, and rapidity of progression of disease did not predict dropout. Level-of-site commitment was the most significant determinant of continued participation in this natural history study of AD, followed by white race, and the inclusion of both husband and wife where one is a patient and the other a control subject.

Aged↗

PubMedDate not supplied

Type A behavior and angiographically documented coronary atherosclerosis in a sample of 2,289 patients.

To determine the relationship between Type A behavior pattern and angiographically documented coronary atherosclerosis (CAD), we analyzed risk factor, behavioral, and angiographic data collected on 2,289 patients undergoing diagnostic coronary angiography at Duke University Medical Center between 1974 and 1980. Multivariable analyses using ordinal logistic regression techniques showed that Type A behavior as assessed by the structured interview (SI) is significantly associated with CAD severity after age, sex, hyperlipidemia, smoking, hypertension, and their various significant interactions were controlled for. This relationship, however, is dependent upon age. Among patients aged 45 or younger, Type A's had more severe CAD than did Type B's; among patients aged 46-54, CAD severity was similar between Type A's and B's; and among patients 55 and older, there was a trend toward more severe CAD among Type B's than among Type A's. These Type A-CAD relationships did not appear to be the result of various factors relating to the selection of patients for angiography. Type A behavior as assessed by the Jenkins Activity Survey was unrelated to CAD severity. These findings suggest that SI-determined Type A behavior is associated with more severe CAD among younger patients referred for diagnostic coronary angiography. The reversal of the Type A-CAD relationship among older patients may be due to survival effects. Inadequate sample sizes, use of assessment tools other than the SI, and failure to consider the Type A by age interaction could account for failures to find a Type A-CAD relationship in other studies. We conclude that the present findings are consistent with the hypothesis that Type A behavior is involved in the pathogenesis of CAD, but only in younger age groups. The Type A effect in the present data is small relative to that of both smoking and hyperlipidemia, however, and future research should focus more specifically on the hostility and anger components of Type A behavior, particularly in younger samples.

Adult↗

PubMedDate not supplied

Binswanger's disease (Part I): The clinical recognition of subcortical arteriosclerotic encephalopathy in elderly neuropsychiatric patients.

The role of vascular disorders in the pathogenesis of dementia has been controversial. Recent studies suggest that subcortical arteriosclerotic encephalopathy (Binswanger's disease), a disorder of white-matter demyelination associated with narrowing of penetrating medullary arteries and arterioles may affect more than 5% of the population over age 65 years. In part I of this paper, the authors present clinical examples and review the clinical literature, including clinical course and radiologic features. Differential diagnosis and treatment options are reviewed. In part II of this paper we will discuss theories of pathogenesis of subcortical arteriosclerotic encephalopathy and implications for the nosology of dementia.

Aged↗

PubMedDate not supplied

Binswanger's disease (Part II): Pathogenesis of subcortical arteriosclerotic encephalopathy and its relation to other dementing processes.

Subcortical arteriosclerotic encephalopathy (SAE) is a common though infrequently recognized dementia of the elderly. The unique vascular anatomy of the subcortical white matter and central brain stem probably predisposes those regions to chronic ischemia and incomplete infarction in the presence of various cardiovascular and hemodynamic insults. Recent studies have begun to define the risk factors for SAE, and others have shown it to be a condition frequently comorbid with the dementias of Alzheimer's disease, the multi-infarct state, and normal pressure hydrocephalus. Recent research into the etiologies of these disorders suggest certain pathogenetic links between them, strongly implying that they are not neatly distinct disease entities, as is commonly believed, and accounting for some of the overlap between these dementing illnesses seen clinically.

Alzheimer Disease↗

PubMedDate not supplied

Used of a guide-wire inserted catheter for acute peritoneal dialysis.

Peritoneal dialysis was performed in 18 children using a new guide-wire inserted catheter technique. Catheter insertion was complicated only by mild bleeding in one patient. The catheters drained well immediately after insertion in 17 of the 18 patients. Catheters were used for an average of 6 days, with a range up to 16 days. Dialysate volumes could be increased quickly in most patients. Late complications were leakage (2), peritonitis (4) and obstruction (3). Leakage did not interfere with dialysis. The peritonitis episodes, which occurred between days 6 and 16 of dialysis, resolved satisfactorily with appropriate antibiotic therapy. The guide-wire catheter can be inserted and used for short term peritoneal dialysis in children.

Acute Kidney Injury↗

PubMedDate not supplied

Low cholesterol level as risk factor for noncoronary death in middle-aged men.

Eighty-six deaths occurred zero to five years (mean, 2.5 years) after the screening investigation in 10,000 middle-aged men in Malmö, Sweden. The men were 47 to 50 years old at the time of the screening and represented 75% of their total birth-year cohorts in Malmö. The mortality showed two peaks, one at the higher end of the cholesterol distribution and the other and more pronounced one at the lower end of the cholesterol distribution. The first peak corresponded to the cardiovascular deaths while the second peak corresponded to the noncoronary death causes, including alcohol-related deaths.

Accidents↗