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Biomedical subjects

D A Holub

Publications and source records attributed to D A Holub.

8 recordsLinked to original sources
PubMed1978

Molecular, microscopic, microstructural and mechanical methods of analyzing pseudoneointimal linings within partial artificial hearts in man and the calf.

Ex vivo molecular, microscopic (cellular), microstructural and mechanical methods have been utilized to evaluate biologic, blood-interfacing linings (pseudoneointimal) formed on textured, fibril-flocked pumping surfaces within abdominal left ventricular assist devices (ALVADs) on partial artificial hearts. Thus far, seventeen human and twenty bovine pseudoneointimal linings (1--28 day pumping durations) have been evaluated by these methods. The results indicate that pseudoneointima begins developing within 24 hours after contact of the pumping surface with blood and is well developed at five days. The linings exhibit surface immunofluorescent fibrinogen activity, viable surface macrophages and histiocytes and scattered erythrocytes at ALVAD removal. Structurally similar linings (20 micrometer to 500 micrometer in thickness) develop in calves and in man. Mechanically, pseudoneointima is a stable, adherent, highly compliant, isotropic structural material. It is linearly elastic and strain-rate independent, with small viscous energy losses under physiologic strains. The methods employed for the evaluation of pseudoneointima provide useful information to determine the suitability of textured or rough surfaces for blood interfacing. The cumulative results indicate that the textured surface approach is useful for intermediate-term clinical ALVAD utilization.

Animals↗
PubMed1978

Intra-aortic balloon pumping: theory and practice. Experience with 325 patients.

Intra-aortic balloon pumping to support the failing circulation is now an accepted therapeutic modality. The device is simple. Insertion can be accomplished rapidly and efficiently in emergency rooms, coronary care units, cardiac catheterization suites and operating rooms, preoperatively, intraoperatively and postoperatively. The hemodynamic effects are immediate and predictable, and the accruing clinical results show increasing survival and hospital discharge rates. In these institutions, mechanical support of the circulation by this and more advanced methods has been formalized within the responsibility of a Circulatory Support Service. The purpose of this report is to summarize some observations and analyses which have been made during care of 325 consecutive postcardiotomy and/or postinfarction cardiogenic shock patients. Historical, theoretical, basic, and applied aspects and current results are included. Foremost are the straightforward concepts of considering the heart as a pump, the failing heart as a failing pump and intra-aortic balloon pumping as a temporary intravascular, auxiliary pump, capable of stabilizing or reversing that failure if utilized early in its evolution.

Adult↗
PubMed1976

The syndrome of multiple endocrine gland insufficiency.

Addison's disease, when caused by idiopathic atrophy of the adrenal cortex, is frequently associated with other endocrine abnormalities. Primary hypothyroidism and hypogonadism have been reported in association with adrenal insufficiency; understandably, such cases may lead to diagnostic confusion with respect to possible pituitary disease. This case study concerns a woman who exhibited, in sequence and over a period of 17 years, hypogonadism, hypoadrenalism, diabetes mellitus and, finally, hypothyroidism. Originally misdiagnosed as having Sheehan's syndrome, she eventually became hyperpigmented. The true nature of her illness was then revealed to be primary insufficiency of multiple endocrine glands, with the demonstration of elevated levels of several pituitary hormones. Because multiple endocrine insufficiencies may coexist or develop with time, we suggest that a patient with a single documented endocrine deficiency be investigated initially and serially for additional glandular deficiencies.

Addison Disease↗