C B Hartley | PubMed Health

PubMed1984

Nontuberculous mycobacteria.

Nontuberculous mycobacteria are identified in almost half of the cultures reported positive for mycobacteria in clinical laboratories in the United States. While many represent saprophytic colonization or laboratory contamination, a significant number of these organisms are the agents of disease. Such organisms can be the cause of pulmonary, soft tissue, cutaneous and lymphatic infections, keratitis, osteomyelitis, postsurgical infection, endocarditis and disseminated disease.

Humans↗

PubMed1982

Spontaneous genetic hypertension in the rat and its relationship to reduced ac cochlear potentials: implications for preservation of human hearing.

We present controlled laboratory studies of the spontaneously hypertensive rat which indicate that hypertension is an important pathophysiological risk factor in age-related hearing loss. Our results are in concert with previous retrospective clinical studies that pointed to this possibility in man. Hypertension as a risk factor for hearing loss is within the bounds of known measures of diagnosis, treatment, and even prevention, with monitoring early in life. Because hypertension is such a major public health problem in the United States, in view of our results it is possible that its treatment and early diagnosis will benefit a significant number of people who would otherwise lose their hearing with advancing age. We compared the round window ac cochlear potential-sensitivity and -intensity functions in 10 female spontaneously hypertensive rats and 10 female normotensive Wistar-Kyoto control rats. The animals were all 12 months old and weighed between 170 and 250 g. The normotensives had higher maximum cochlear potential-intensity values compared with the hypertensives: 1,000 Hz (P less than 0.005), 5,000 Hz (P less than 0.005), and 10,000 Hz (P less than 0.01). One-microvolt isopotential cochlear potentials for the low frequencies of the normotensives showed greater sensitivity than those of the hypertensives: 100 Hz (P less than 0.05), 200 Hz (P less than 0.10), 290 Hz (P less than 0.05), and 2,000 Hz (P less than 0.10). Blood pressure of the hypertensive group was significantly greater than that of the normotensive rats (P less than 0.001). The hearts and aortas of the hypertensive group were hypertrophied. Autonomic imbalance, platelet aggregation, decreased arterioles, and natriuretic hormone were discussed as possible etiologies for the measured sensory hearing loss.

Acoustic Stimulation↗

PubMed1975

Polyamines in cystic fibrosis.

Polyamine concentrations have been measured in blood samples from a series of cystic fibrosis (CF) patients and control subjects. Analyses were made by a fluorometric method, in which the amines were reacted with dansyl chloride and separated by thin layer chromatography on Kieselguhr. There was no significant difference between the polyamine concentrations of blood samples from CF patients and control subjects. Also, the spermidine-spermine ratio was similar in both groups. Polyamines were also analyzed in exocrine fluids, and although none could be detected in either CF or control sweat or saliva, significant amounts of spermine and spermidine were present in all samples of bile and duodenal fluids. It thus seems likely that the biliary route is a significant pathway in the human for excretion of polyamines. The observation that polyamines are excreted in considerable concentrations via the bile in children may be of interest in view of the reports of elevated urinary polyamine concentrations in neoplastic states. Since measurable amounts of spermine and spermidine were detected in all six bile preparations available for this study, analysis of these substances in bile may be of benefit in particular cases.

Bile↗