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Biomedical subjects

E N Albert

Publications and source records attributed to E N Albert.

At least 19 recordsLinked to original sources
PubMed1988

Morphological changes in cerebellum of neonatal rats exposed to 2.45 GHz microwaves.

One-day and six-day old Sprague-Dawley rats were exposed in the far field to 2.45 GHz (cw) microwaves at 10 mW/cm2 for five consecutive days, 7 hours per day (SAR 2W/kg). Pups were euthenized one day after exposure and the cerebella processed for light and electron microscopy. Matching cerebellar sections and folia from irradiated and sham irradiated animals were examined. Light microscopic examination revealed the presence of small deeply-stained cells with hyperchromatic pyknotic nuclei within the external granular layer (EGL). The number of these pyknotic cells in the experimental animals was nearly twice that in the controls. The Nissl bodies in Purkinje cells were finely dispersed. In some experimental animals mononuclear cellular infiltration was demonstrated. Under the electron microscope the deeply-stained pyknotic small cells presented electron dense nuclei with clumped chromatin, extrusion or disintegration of the nucleus, ruptured nuclear membrane, and the vacuolization of the cytoplasm. Eventually these cells became phagocytosed by surrounding EGL cells. Most of the Purkinje cells of experimental animals showed small, disorderly arrays of rough endoplasmic reticulum (RER) instead of the typical orderly stacks of parallel arrays. These observations suggest that microwave radiation may interfere with early genesis of cerebellar microneurons and alter the metabolic status of Purkinje cells. However, this effect might be reversible.

Animals↗
PubMed1987

Effect of amplitude-modulated 147 MHz radiofrequency radiation on calcium ion efflux from avian brain tissue.

Cerebral cortex tissue slices and cerebral hemispheres prepared from Gallus domesticus chicks were exposed to 147 MHz radiofrequency radiation, amplitude modulated at 16 Hz and applied at a power density of 0.75 mW/cm2, to determine the effect of such exposure of 45Ca2+ efflux from the avian brain tissue. Statistical analysis of these data demonstrates that such exposure has no significant effect on 45Ca2+ efflux.

Animals↗
PubMed1985

Structural and functional characteristics of cardiac myocytes.

Canine and rat cardiac myocytes, prepared by proteolytic disaggregation, retain morphological and topographical features of intact tissue. Cells are rod-shaped and are cleanly separated at their sarcolemmal and intercalated disc borders. Cells demonstrate glucose and fatty acid uptake and metabolic features comparable to intact organ, and are responsive to insulin and epinephrine, but nor carnitine. Although rat cardiac cells contain immunodetectable lipoprotein lipase, they are incapable of metabolizing extracellular lipoprotein triglyceride, nor the glycerol or monoglyceride moieties of the triglyceride. These and other metabolic characteristics suggest that cardiac cells can provide a useful cellular model for studies on cardiac pathophysiology.

Animals↗
PubMed1984

Neocortical transplants in the rat brain: an ultrastructural study.

Electron microscopic analysis of neocortical transplants in the cerebellum of the host animals showed that the nerve cells, glial cells, and neuropil of the transplants were normal. These transplants showed anatomical integration with the host brain through various regions of interface. Neuropil interfaces were found to have a high density of synaptic profiles, and medullary interfaces had a very small number of synaptic profiles.

Animals↗
PubMed1981

Reversible microwave effects on the blood-brain barrier.

Low level microwave exposure of Chinese hamsters resulted in reversible permeability of the blood-brain barrier (BBB) to horseradish peroxidase (HRP). Lesions were grossly visible in random areas of the brain immediately following exposure, but were not as common following a 1 h recovery period and were absent after a 2 h recovery period. The apparent route of increased permeability was via endothelial vesicular transport, since reaction product was not seen passing through the endothelial tight junctions. In addition, endothelial flooding of HRP, platelet aggregation and perivascular edema were observed only in experimental animals. Possible mechanisms of the enhanced vesicular transport are discussed.

Animals↗
PubMed1981

Fiber contribution from the mesencephalic nucleus of the trigeminal nerve to the trochlear nerve in the cat: a histological quantitative study.

The fiber connections between the trigeminal mesencephalic nucleus and tract and the trochlear nerve root of 15 cats were examined after silver impregnation of the pontomescencephalic region of the brains. The results revealed that: (a) some of the mesencephalic root fascicles join the trochlear root, (b) some of the mesencephalic root cells contribute their processes to the trochlear root, and (c) some mesencephalic cells are found amidst the fibers of the trochlear nerve during its intrabulbar course. The fibers of the trochlear nerve were counted at certain preselected sites before and after crossing the mesencephalic nucleus. The statistical data obtained indicated that the trigeminal mesencephalic root contributes 4-10% of the fibers of the trochlear nerve, before it crosses the mesencephalic nucleus.

Animals↗
PubMed1981

Effect of nonionizing radiation on the Purkinje cells of the uvula in squirrel monkey cerebellum.

Pregnant squirrel monkeys were exposed to 2450-MHz (CW) microwaves at an equivalent power density of 10 mW/cm2 (SAR 3.4 mW/g) for three hours daily in a cavity-cage module. The exposure began when pregnancy was determined by a hormonal method, and continued through of offspring's first 9.5 months. After irradiation, the brain of the offspring were fixed with formaldehyde, and the inferior vermis of each cerebella was removed and processed for histologic observations. Purkinje cell density in the uvula was determined in sagittal serial section. There was no significant difference between control and experimental animals in the number of Purkinje cells per mm of Purkinje cell line (linear density), as well as in the density of Purkinje cells in the Purkinje cell layer.

Animals↗
PubMed1981

Effect of nonionizing radiation on the Purkinje cells of the rat cerebellum.

In one experiment, Sprague Dawley rats (16-21 days of gestation) and their offspring were exposed to 100-MHz (CW) electromagnetic radiation at 46 mW/cm2 (SAR 2.77 mW/g) for 4 h/day for 97 days. In another experiment, the pregnant rats were irradiated daily from 17 to 21 days of gestation with 2450-MHz (CW) microwaves at 10 mW/cm2 (SAR 2 m W/G) for 21 h/day. In a third experiment, 6-day old rat pups were irradiated 7 h/day for five days with 2450-MHz radiation at 10 mW/cm2. Equal numbers of animals were sham irradiated in each group. Quantitative studies of Purkinje cells showed a significant and irreversible decrease in rats irradiated during fetal or fetal and early postnatal life. In animals exposed postnatally, and euthanized immediately after irradiation, significant decrease in the relative number of Purkinje cells was apparent. However, restoration apparently occurred after forty days of recovery.

Age Factors↗
PubMed1981

A fascial canal for the great saphenous vein: gross and microanatomical observations.

The course of the great saphenous vein in a fascial canal derived from the deep fascia of the lower extremity is described. The fascial canal is absent in 15% of the cases. In 85% of the cases, the sheath surrounding the great saphenous vein is continuous from the thigh to the leg and supports the vein from the hydrostatic pressure of the blood, being absent only in the uppermost and the lowermost quarters of the vein in the thigh and the leg, respectively. Thus, up to one quarter of the vein is ensheathed in 30%, up to one half in 45% and up to three quarters in 10% of the cases studied. The absence of this fascial envelope of the vein, in whole or in part, may be involved in the pathogenesis or the complications of the varicosities of the great saphenous vein along with the well-known aggravating factors.

Anthropometry↗
PubMed1981

Some quantitative histological observations on the growing cerebellum of the albino rat. (Dimensions of the cortical layers and white core and relative number of Purkinje cells).

The cerebella of 38 Sprague Dawley rats of various ages have been studied histologically by sectioning in certain parasagittal planes. The age groups were chosen from the early postnatal developmental stage (6, 11 and 16 days), around puberty (41, 46 and 51 days) and maturity (210 days). The sections yielded quantitative data with regard to the dimensions in parasagittal sections, of the entire cerebellum, the cerebellar cortex, the white core, the molecular layer and the granular layer, as well as, the differential and proportional growth of these layers at the above ages. The relative number of Purkinje cells per mm2 of sectional area of the cortex was also determined. The information presented in this study is of indicative value of the pattern of the growing cerebellum and of the ages in which the various layers and the relative number of Purkinje cells assume adult values.

Aging↗
PubMed1980

Exogenous secretory proteins do not inhibit carbamylcholine-stimulated release of pulse-labelled secretory proteins from rat pancreatic tissue slices.

Experiments were conducted to test the concept that the results of secretion studies employing pancreatic tissue slices are significantly biased by the distribution of exocrine secretory proteins between the tissue and the incubation medium. The findings demonstrate (1) that the kinetics of release of pulse-labelled secretory proteins from cholinergically-stimulated tissue slices are independent of the concentration of exogenous exocrine secretory proteins and (2) that if there are bidirectional fluxes of secretory proteins across the cell membrane of pancreatic exocrine cells, these fluxes do not account for the fractional release of pulse-labelled secretory proteins.

Animals↗
PubMed1979

Morphological and metabolic studies on adult cardiac myocytes.

We have previously described detailed procedures for isolating rat and canine myocytes from adult ventricular tissue, and have investigated ultrastructural and functional properties of these cells. The effects of isolation on cell morphology were tested by comparative scanning (SEM) and transmission electron microscopy (TEM) of adult canine cardiac myocytes. Cells cleanly separated at the lateral sarcolemmal borders and at the intercalated discs. Since the cells were contracted during fixation, SEM of the lateral cell borders showed longitudinal folds and transverse ridges. There were rows of regular protrusions corresponding to the mitochondria immediately beneath the sarcolemmal surface. Openings in the sarcolemmal membrane occurred at regular intervals at the level of the Z-bands and may represent the sites of externalization of the transverse tubular system. By SEM, the intercalated disc junction appeared as a microvillar border and this corresponded directly to the scalloped appearance seen by TEM. A controlled sonication procedure was developed to allow specific removal of the sarcolemma without disruption of underlying organelles. This allowed visualization of the cellular organization of myofibrils, mitochondria and the transverse tubular system. These cells retain biochemical and enzymatic characteristics of adult dog cardiac tissues such as ouabain and insulin sensitivity, fatty acid and lipoprotein uptake and metabolism, and prostaglandin synthesis. This cytological preparation permits the correlation of these types of metabolic studies with the known functions of isolated subcellular organelles of the myocardium.

Animals↗
PubMed1978

Pyridinolcarbamate and experimental atherosclerosis. Correlation of hypocholesterolemic and antiatherogenic effects.

Rabbits were maintained for 12 weeks on either a control or hypercholesteremic dietary regime, or on comparable diets supplemented with pyridinolcarbamate (PDC) at a level of 30 mg/kg body weight/day. Blood was obtained from all rabbits prior to study and at two-week intervals for analysis of serum cholesterol, phospholipid phosphorus and triglycerides. Animals from each group were sacrificed at 4-week intervals for quantitative assessment of the degree of atherosclerotic involvement of the aorta. All animals in the four groups consumed their entire daily allowance (100 g) of their respective diets, and weight gains throughout the feeding period were comparable in the 4 groups. PDC given with the control chow diet had no effect on serum cholesterol levels but did result in persistent decrease in serum triglycerides and a variable decrease in serum phospholipids during the 12-week feeding period. None of the rabbits on the chow diet, with or without PDC, had any evidence of aortic lesions during the experimental period. Rabbits fed 1% cholesterol administered with chow exhibited markedly elevated levels of serum cholesterol and phospholipids, while serum triglycerides were not significantly different than in the control group. In these animals there was a rapid and progressive increase in aortic atherosclerosis throughout the study, and at 12 weeks plaque involvement was 74 +/- 8% of the aortic surface. Addition of PDC to the 1% cholesterol--chow diet resulted in significantly lowered levels of serum cholesterol and phospholipids, but these remained elevated compared to the control levels. There was also a dramatic reduction in the rate and extent of aortic plaque formation. Thus, after 12 weeks on diet, only 27 +/- 6% of the aortic surface showed evidence of atheroma. The data suggest that PDC significantly decreases the hypercholesteremia resulting from feeding 1% cholesterol to rabbits, and that this may be largely responsible for the antiatherogenic effect of this drug.

Animals↗