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Biomedical subjects

M D Haust

Publications and source records attributed to M D Haust.

At least 55 records · Page 3Linked to original sources
PubMed1981

Aortic atherosclerosis in hypertensive rabbits treated with anti-hypertensive agents having different effects on arterial flow disturbances. 1. Extent of surface involvement.

Hypertension may be considered a disorder of increased energy in the blood, with two components: increased pressure energy may promote arteriolar disease, whereas arterial diseases such as atherosclerosis may be more closely related to flow disturbances (turbulence, boundary layer separation, high shear, or axial stream impingement) due to increased kinetic energy. Previous studies have shown that hydralazine aggravates turbulence in stenosed carotid arteries, whereas propranolol diminishes turbulence. To assess the effect of these drugs on the progression of atherosclerosis, the drugs were administered subcutaneously to rabbits made hypertensive (one kidney Goldblatt) and hypercholesterolemic (1% cholesterol diet for 4 weeks). Appropriate controls with normal, only hypertensive and hypertensive-hypercholesterolemic untreated rabbits were employed. A total of 36 rabbits was used. The extent of the aortic surface involvement with atherosclerotic lesions was assessed by morphometric analysis of magnified photographs. Although the extent or surface involvement did not differ significantly between the untreated or treated hypertensive rabbits, there was an interesting difference in the relationship between blood pressure and extent of surface involvement. In the untreated and hydralazine treated rabbits, there was a direct correlation between increasing blood pressure and extent of lesions; in the propranolol treated group, this relationship was abolished.

Animals↗
PubMed1980

Placental infiltration in congenital neuroblastoma: a case study with ultrastructure.

Examination of a large, oedematous placenta of a still-born infant showed an extensive infiltration of chorionic villi by malignant cells; the nature of these was not apparent by light microscopy. Ultrastructural examination of these cells showed the presence of cytoplasmic granules whose size and appearance were consistent with those characteristically present in neuroblastomas. Whereas no necropsy was carried out on the still-born infant, it may be assumed, in keeping with the available data, that the placental metastases were derived from a congenital neuroblastoma. Infiltration of the villous stroma by metastatic neuroblastoma observed in the present case was not reported previously as in all other known instances the metastatic neuroblastomatous cells were confined to the lumina of the chorionic vessels.

Female↗
PubMed1980

Unusual clinical and ultrastructural features in a boy with biochemically typical mannosidosis.

A 4 1/2-year-old boy with a history of recurring respiratory tract infections and seizures, and evidence of severe retardation of psychomotor development and growth, lacked the coarse facial features, skeletal changes and other clinical stigmata generally associated with mannosidosis, but the total alpha-mannosidase activity in his leukocytes, cultured fibroblasts and liver were no more than 10% of the control mean. Studies of the residual alpha-mannosidase enzyme suggest a specific deficiency of the thermostable isoenzyme with an acidic pH optimum. The alpha-mannosidase in the fibroblasts of our and another (control) patient with mannosidosis had a reduced affinity for the substrate 4-methylumbelliferyl-alpha-D-mannoside. Light microscopy of the liver biopsy showed an increase in connective tissue often distorting the hepatic architecture; numerous tiny vacuoles, small dense and lipid bodies in most hepatocytes, and similar but more extensive changes in sinusoidal cells; and sinusoidal pools of hepatocytic debris. Electron microscopy of hepatocytes revealed vacuoles similar but not identical to those described in reported mannosidosis patients, and in addition several forms of secondary lysosomes; prominent peroxisomes (microbodies); increased numbers of profiles of smooth endoplasmic reticulum; dilated rough endoplasmic reticulum containing traces of fine granulo-fibrillar material; increased numbers of rosettes of alpha particles of glycogen and reduced numbers of mitochondria with alterations in their distribution, size and configuration. It is believed that the usual clinical and hepatic ultrastructural features in our patient reflect another variant of mannosidosis.

Abnormalities, Multiple↗
PubMed1979

Morphological findings in idiopathic calcification of the ascending aorta and aortic valve affecting a young woman.

The pathology of a case of idiopathic calcification affecting the ascending aorta in a young woman is presented. A varying width of media throughout the aorta and extending into its proximaques of calcium, found in the acellular media, were confined to the ascending aorta. No inflammatory or reparative reaction was seen in the vessel wall. Electron microscopically, the calcium seemed to have an affinity for elastic tissue elements of all sizes and the mode of deposition appeared to be by 'avenues' of the microfibrillar component. Possible pathogenetic mechanisms are discussed.

Adolescent↗
PubMed1979

Long spacing collagen in dermal disorders.

Electron microscopic studies of biopsy material from the vulva of six patients with lichen sclerosus et atrophicus and two patients with condyloma latum, and from the skin of the back and shoulder of one patient with scleromyxoedema and the forearm of one patient with macular amyloidosis revealed the presence of long spacing collagen (LSC) of one patient with macular amyloidosis revealed the presence of long spacing collagen (LSC) intermingled with an increased amount of ground substance and extracellular microfibrils. The presence of LSC in condyloma latum is believed not to have been reported previously. The LSC displayed an axial periodicity varying from 1000 to 2000 A. Our studies support the contention that the appearance of LSC is not specific of any disorder, and the formation of LSC is associated with the presence of increased amounts of glycosaminoglycan-rich ground substance and the abundance of microfilaments in the extracellular space.

Amyloidosis↗
PubMed1977

Fat-containing uterine smooth muscle cells in "toxemia": possible relevance to atherosclerosis?

Uterine smooth muscle cells in "toxemia of pregnancy" contain varying amounts of fat--a feature to date believed to characterize only the arterial smooth muscle cells in atherosclerotic lesions. Thus, the smooth muscle cells at these two sites do not differ essentially in their reactivity to certain forms of injury: hypoxia may represent an injurious factor common to both "toxemia" and atherosclerosis. These observations imply that the view that the arterial smooth muscle cells are biologically different than are those elsewhere may no longer be tenable.

Arteries↗
PubMed1977

Myogenic foam cells in explants of fatty dots and streaks from rabbit aorta. Morphological studies.

Present studies indicate that in explants of early atherosclerotic lesions removed from aortae of young rabbits on a 1% hypercholesterolemic diet for four and seven weeks respectively, myogenic foam cells (MCF's) were capable of emigrating into the culture medium and maintained their ability to produce microfibrils, elastic tissue elements, and collagen fibrils. In explants of the smallest lesions (fatty dots and small streaks) the MFC's divided prior to, or while emigrating. At the interphase between the primary tissue and the culture medium they contained in intracytoplasmic vacuoles fragments of elastic tissue and extraneous substances which were reminiscent of cellular debris. It is possible that this phenomenon represents a true phagocytic property of the MFC's. All formed extracellular connective tissue components were also produced by the emigrated MFC's in the tissue surrounding the cellular outgrowth. In the large fatty streaks cell division was observed at the interphase between the tissue and culture medium, but not within the substance of the explant; here cellular necrosis was prominent. The fat inclusions in the MFC's of explants and the outgrowth had the appearance of conglomerateds of unorganized, and only at times concentric, membranous profiles rather than that of homogeneous droplets observed by electron microscopy in these cells in tissue sections. In the outgrowth from explants of normal aortic areas adjacent to the lesions a moderate number of smoot muscle cells contained fat inclusions; these were almost totally absent in cells of the primary aortic cultures from normal aortae. It is conceivable that the migratory and phagocytic properties of the MFC's observed in the present study relate to some aspects of regression of atherosclerotic lesions; this, however, remains highly speculative at present.

Animals↗
PubMed1976

Ultrastructure and peroxidase of leucocytes in five patients with juvenile form of ceroid lipofuscinoses.

Peripheral leucocytes obtained from five patients with clinical histories and funduscopic findings typical of the juvenile form of the so-called neuronal ceroid lipofuscinosis (NCLF) (synonym: Spielmeyer-Vogt disease) were assayed for peroxidase activity and examined by electron microscopy. The peroxidase levels were considerably lower in three but normal in two patients. Ultrastructurally, the lymphocytes of all five patients showed the presence of tubulo-membranous cytosomes many displaying the fingerprint images at present regarded as being typical for the NCLF. The possible implications of the discrepancy between the morphological observations and the enzymatic findings are discussed.

Adolescent↗
PubMed1976

Yellow pulmonary hyaline membranes.

Yellow pulmonary hyaline membranes were observed at autopsy in 16 newborn infants between 1972 and 1974 in four hospitals of Philadelphia, Pa., and Newark, N.J. Other pediatric pathologists in this country and in Spain have seen the same lesion within the last decade. Chemical analysis of affected lung tissue, histochemistry, and electron microscopy show the yellow color to be due to the presence of bilirubin. No substantial clues concerning the basic etiology or mechanism for the formation of these unique membranes emerge from a detailed review of clinical and postmortem data nor from comparison of these data with those for 68 control infants with the usual acidophilic pulmonary hyaline membranes. We are left, however, with the impression that prolongation of life, relatively elevated levels of serum bilirubin, and protracted assisted ventilation (with either CPAP or PEEP) are intimately related to their formation.

Bilirubin↗