Biomedical subjects

A Mari

Publications and source records attributed to A Mari.

At least 109 records · Page 6Linked to original sources

PubMed1987

An epidemiologic study of mandibular dysfunction dependence on different variables.

Age and sex characteristics of different signs and symptoms of mandibular dysfunction were studied in 600 randomly selected urban persons. With regard to mandibular mobility marked differences were observed between the sexes, and a steady decrease parallel with ageing. Against this, the percentages of the objective dysfunction signs of impaired mobility and TMJ-sounds, as well as those of the pooled percentages of all the objective signs (Di-I + II + III), increased parallel with ageing. The percentages of headache occurrence peaked in different age groups for men and women. Statistically significant correlations were found between headache, parafunctions, stress, age, the existence of a preferred chewing side, as well as several dental-occlusal factors, and the prevalence of mandibular dysfunction; between Ai and Di according to Helkimo, and between excessive tooth wear and parafunctions.

Adolescent↗

PubMed1987

Non-steady state: error analysis of Steele's model and developments for glucose kinetics.

The model proposed by Steele (Ann. NY Acad. Sci. 82: 420-430, 1959) to compute rates of appearance and disappearance in non-steady state is subjected to theoretical analysis. It is shown that this model introduces an error with two components, one dependent on the volume of the compartment, the other related to the complex configuration of the system. The errors depend on the time course of specific activity, change differently with time, and may take the opposite sign but they do not, in general, cancel each other. Corollaries of this analysis are the following: there is no single pool-fraction value satisfactory under all non-steady-state situations; keeping tracer specific activity as constant as possible during the experiment minimizes both errors; and non-steady-state analysis demands proper modeling of the system. Tracer experiments were carried out in five normal volunteers. Plasma [3-3H]glucose concentration was first brought to equilibrium by means of a primed constant 2-h infusion, and then the steady state was perturbed by a 2-h euglycemic insulin (1 mU X min-1 X kg-1) clamp, realizing a transition between a basal and a euglycemic hyperinsulinemic steady state. These data were analyzed with Steele's equation, the two compartment models of Radziuk et al. [Am. J. Physiol. 234 (Endocrinol. Metab. Gastrointest. Physiol. 3): E84-E93, 1978], and a new model based on a study on glucose kinetics carried out in the two steady states separately. Steele's equation yielded negative values for hepatic glucose production already 40 min into the clamp and throughout the study. The average value of glucose production during the 2nd h was -0.88 mg X min-1 X kg-1; the suppression of basal release over the 2-h period was 115%. In contrast, the new model calculated a mean glucose production of 0.37 mg X min-1 X kg-1 during the 2nd h and an overall suppression of 62%; no negative values were obtained.

Female↗

PubMed1987

Reconstructing the rate of appearance of subcutaneous insulin by deconvolution.

In this paper a deconvolution scheme is presented to reconstruct the rate of appearance of subcutaneously injected insulin. Relevant aspects of experiment design are briefly described. Intravenous insulin kinetics are modeled to determine the impulse response of the system. The deconvolution problem is not ill conditioned and is solved using a least-squares method without imposing constraints on the input. An estimate of the error of the reconstructed input is provided. The reliability of the deconvolution scheme is tested by means of an independent validation study. Finally, the different sources of error that affect the method are discussed, and a figure of the global error is derived.

Humans↗

PubMed1987