In this study, phenotypic expression of spontaneous elastic laminae defects within the rat abdominal aorta was examined. Lesions in Brown Norway (BN) rats were compared with those of New Zealand genetically hypertensive (GH) rats. BN and GH rats were cross-bred to determine the phenotypic expression of these lesions in successive F(1) and F(2) generations. Lesions were assessed by distribution, number and a semiquantitative index of severity. All BN aortae contained numerous elastic tissue defects. In comparison, GH aortae contained only occasional elastic tissue lesions. F(1) aortae contained lesions in numbers similar to those of the parental BN strain; however, F(1) lesions were of significantly greater severity. Within the F(2) generation, a wide range in both lesion numbers and severity indices was observed, with approximately a quarter of animals having lesion numbers analogous to the GH parental strain. In conclusion, this study indicates that the spontaneous elastic tissue lesions observed within BN rats are consistent with an autosomal dominant, possibly single gene, effect. Moreover, epistatic effects, derived from the GH strain, may influence the severity of these lesions. The gene(s) responsible may be important in the development of conditions such as arteriosclerosis and aneurysms in humans.

Animals↗

PubMedDate not supplied

Vocal cord dysfunction - an industrial health hazard.

Vocal cord dysfunction has a definite incidence of association with high environmental noise levels. Our study has shown roughly an 8% incidence of vocal cord dysfunction (vocal cord nodules, vocal cord polyps and chronic laryngitis) in individuals working in high noise environments. In addition, those individuals who have surgery for vocal cord nodules and who work in high noise environments will have over a 30% incidence of recurrent vocal cord dysfunction following surgery. Our study indicates that females tend to be more at risk in high noise environments than males.

Female↗

PubMedDate not supplied

Quantitative and objective evaluation of vocal cord function.

Objective and quantitative evaluation of vocal cord function is a goal that has been difficult for voice clinicians to obtain. To be useful as a clinical screening tool it must be easy to perform, it must produce numerical storable data, it must have a high degree of accuracy, and it must be cost-effective. The results of this study have shown that using the perturbation factor and the equipment described, a successful rate of greater than 93% can be obtained in evaluating vocal cord dysfunction. The results further indicate that this equipment can be used much in the same way as an audiogram to follow-up and clinically evaluate on an objective basis the function of the vocal cords.

Electrodiagnosis↗

PubMedDate not supplied

Flexible nontoxic fiberoptic delivery system for the carbon dioxide laser.

Presented is the first flexible, thin, nontoxic fiber to carry carbon dioxide laser energy. The physical characteristics of this fiber, examples of its use through a fiberoptic bronchoscope, and its features and applications are described.

Animals↗

PubMedDate not supplied

Identification of quantitative trait loci for non-insulin-dependent diabetes mellitus that interact with body weight in the Otsuka Long-Evans Tokushima Fatty rat.

Non-insulin-dependent diabetes mellitus (NIDDM) is a prototypical multifactorial disease. Genetic predisposition and obesity are major risk factors for NIDDM development and the interactions between these factors are likely to be important in the etiology of this disease. The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is one of the best animal models of NIDDM, since the OLETF rat develops NIDDM with mild obesity that is very similar to human NIDDM. Therefore, the OLETF rat is a powerful model for investigating the interaction between genetic susceptibility to NIDDM and obesity. In this study, our goal was to clarify the relationship between an individual NIDDM susceptibility locus and obesity in the OLETF using a molecular genetics approach. We identified four novel quantitative trait loci (QTLs) that contribute to the susceptibility to NIDDM, none of which shows significant linkage with body weight. However, Nidd1/of on chromosome 7 and Nidd2/of on chromosome 14 have an interaction with body weight. In contrast, one locus was mapped to chromosome 10 for body weight, but not to fasting or postprandial glucose levels. These data illustrate that NIDDM and body weight are under separate genetic control in the OLETF yet interact to yield the final disease phenotype in the two Nidd/of loci. In addition, body weight could be used in place of body mass index as an indicator of obesity in our experimental system of genetic study. This study will facilitate the understanding of the complex interaction between genetic susceptibility to NIDDM and obesity.

Animals↗