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Biomedical subjects

J Hart

Publications and source records attributed to J Hart.

At least 253 records · Page 14Linked to original sources
PubMed1985

Severe alterations of red blood cells from the vessels of colorectal tumors.

The RBCs from vessels supplying the tumors of 14 patients with colorectal carcinoma were examined with the scanning electron microscope. In all of them a great variety of alterations in the shape and the cell membrane were found. Erythrocytes from the vessels of healthy colonic tissue of the patients were found to have a normal appearance. Since fibrin thrombi were present in a few vessels of only six patients, the possibility that the alterations were due to mechanical trauma was not likely. This observation may serve as an additional explanation for the anemia observed in patients with colorectal carcinoma.

Adenocarcinoma↗
PubMed1985

Growth of human basophil lines derived from chronic myelocytic leukaemia cells in vitro: ultrastructure and X-ray microanalysis studies.

Mononuclear cells from the peripheral blood of patients with chronic myelocytic leukaemia were grown and expanded in liquid culture in the presence of Con A-conditioned medium. An accelerated development of cells of the basophilic lineage was observed and resulted in the appearance of 85% mature basophils after 14 days of incubation. Transmission electron microscopy of developing basophils showed changes in the nucleus and active granule formation in the cytoplasm. By scanning electron microscopy, the immature cells were relatively smooth in comparison with the mature basophils which showed membranous microvilli. The chemical content of the cells at different days of culture was detected by X-ray microanalysis. Immature cells were characterized by a high level of phosphorus with a low level of sulphur. As maturation progressed, the amount of phosphorus decreased, while the level of the sulphur increased, reaching its highest peak in the mature basophils. The different amount of sulphur found in the cells during the maturational process most probably represents the amount of heparin located in the cell granules. This finding may be useful for studying the influence of growth factors on the development and differentiation of human basophils.

Basophils↗
PubMed1985

Transformation of erythrocytes to spherocytes following incubation with malignant cells.

Incubation of erythrocytes from controls and patients with colorectal carcinoma with tumor cells, or their metabolites, caused transformation of the normally-shaped cells to spherocytes. It is assumed that abnormal metabolites produced by malignant cells affect the cell membrane inducing the subsequent appearance of spherocytes. The increased destruction of these cells by the reticuloendothelial system may serve as an additional factor for the explanation of anemia accompanying malignant diseases.

Colonic Neoplasms↗
PubMed1984

The fate and impact of oil and oil-dispersant mixtures in freshwater pond ecosystems: introduction.

Oil and oil-dispersant mixtures were added to the surface waters of a series of man-made ponds. The fate of the oil and dispersant (Norman Wells crude and Corexit 9527 respectively) were studied as well as the impact of the added chemicals on the ponds' ecosystems. Elements of the ecosystems studied include bacteria, fungi, phytoplankton, periphyton , proto- and mesozooplankton , zoobenthos and surface insects. In addition a number of water quality parameters were regularly monitored. Comparisons were made between oil-treated and control ponds, as well as oil-dispersant treated and oil and/or control ponds. This paper describes the experimental set up and provides a summary of the findings reported in the following five papers.

Animals↗
PubMed1984

The fate of oil and oil-dispersant mixtures in freshwater ponds.

The fate, distribution and composition of oil and oil-dispersant mixtures were studied in a series of five, lined, inground ponds containing sandy gravel sediment and mesotrophic water. Normal Wells crude oil and Corexit 9527 were added at nominal concentrations of 100 and 20 ppm, respectively, to two of the ponds, and the crude oil alone was added at 100 ppm to a third pond. The water surface, water column, the sediment, pond liner and attached biota were systemically sampled for a year. While only about 2% of the oil remained in the water column of the pond with no dispersant addition, in the pond with the dispersant, about 10% of the oil persisted in the water for several weeks. Most of the oil initially dispersed in the water returned to the water surface, then eventually sank to the sediment. Thinner surface films showed a higher dispersant content than the thicker slicks , and the thinner films had higher infrared carbonyl absorption. Final distribution calculations revealed that about 45% of the oil had degraded in the oil-dispersant-treated ponds during the one year study, while only 23% could not be accounted for in the oil pond. Changes in the oil composition during the experiment were similar in all ponds, with no evidence to suggest that the dispersant affected oil composition in any special manner.

Fresh Water↗
PubMed1984

Cytoplasmic inclusions and X-ray microprobe analysis in a case of prolymphocytic leukemia.

A patient with prolymphocytic leukemia is described. The peripheral blood and bone-marrow cells contained nuclear pockets, bridges, and appendices, as well as cytoplasmic inclusions that were not membrane bound or connected with the endoplasmic reticulum. X-ray microanalysis of the cells showed them to contain large amounts of phosphorus, sulfur, chlorine, and calcium, as well as a smaller amount of sodium and magnesium in comparison with control lymphocytes. When compared with lymphocytes of a patient with chronic lymphocytic leukemia (CLL), the patient's cells showed higher amounts of magnesium, sulfur, and chlorine, while the sodium content was decreased. The usefulness of electron microscopy and X-ray microanalysis in the diagnosis of this type of leukemia is discussed.

Adult↗
PubMed1984

SLIPS. A data base system for computer storage and analysis of phonological errors.

The analysis of phonological errors made by normal individuals (slips of the tongue) and brain-damaged patients (paraphasias) is a challenging problem. SLIPS is an experimental data base system for computer storage and analysis of such errors. This paper introduces SLIPS and describes its main features. Some of the problems that arise in analyzing phonological error data are explained, and examples of their solution are presented.

Computers↗
PubMed1984

Plasma ascorbate concentrations and blood cell dehydroascorbate transport in patients with diabetes mellitus.

Rates of dehydroascorbate uptake by blood granulocytes and mononuclear cells are slower, and plasma ascorbate concentrations are lower, among persons with diabetes mellitus than in nondiabetic subjects. These measurements do not correlate with one another or with simultaneously measured plasma glucose or glycosylated hemoglobin; they do not differ with type of diabetes or mode of treatment. In those diabetic granulocytes that exhibit slow dehydroascorbate uptake, maximal velocity (Vmax) transport rates for dehydroascorbate, 2-deoxyglucose, and 3-O-methylglucose are decreased, each to the same degree, while Km values for transport of these ligands are not different from those observed in nondiabetic cells. Since diffusion of these ligands is facilitated by a common transporter, these observations may reflect decreased numbers of glucose transporters in the plasma membranes of some diabetic leukocytes.

3-O-Methylglucose↗
PubMed1984

An outbreak of amoebic infection in a kibbutz population.

The cause of a reported outbreak of abdominal cramps and diarrhoea in a kibbutz in the Western Negev, Israel, was sought. Over 25% of the kibbutz population was found to harbour Entamoeba histolytica, a very high rate by Israeli standards. The highest frequency of infection was in the nought to nine-year-old group. High frequencies were also observed among 30- to 49-year-old women. The sanitary and hygienic conditions in the kibbutz, checked at the time of the epidemic and five years later, were extremely poor. These findings support the generally accepted idea of the close relationship between personal hygiene, sanitary food conditions and amoebic infection.

Adolescent↗
PubMed1984

Analyzing and comparing the performance of two real-time playback systems.

A technique used in animated computer graphics involves the use of real-time playback. This method is used when it is not possible to display frames of display code in real-time. Instead, frames are compiled in advance at non realtime rates, saved in secondary storage, and played back at desired realtime speeds. The basic design and operation of two such systems will be considered. The more powerful of the two is built upon an Evans and Sutherland picture System I and utilizes animated vector graphics. The other playback system is built upon a Terak micro computer display and represents an example of rudimentary raster graphics animation. The synchronization, buffering, blocking and man-machine interfaces of both systems are detailed thus spotlighting their operational behavior. A comparison of the two systems show: that similarities in the logical organization of each system exist; that both systems are input bound; and both require their image files to be built on other computer systems. The differences in the performance of the two systems can be attributed to technological differences between the two systems; the retrieval rates of their respective disk subsystems; and differences in the intent and purpose behind the design of each machine. The systems are demonstrated by applying them to chemical modeling. It is determined that playback is a useful technique for examining complicated sequential situations or for providing the concise and convenient representation of large amounts of data.

Computer Graphics↗
PubMed1984

Synergistic effect of N-acetyl-D-glucosamine (NAG) on mitogenic, antigenic and allogeneic stimulation of normal human lymphocytes.

The effect of N-acetyl-D-glucosamine (NAG) on in vitro stimulated human peripheral blood lymphocytes was investigated. NAG was added to lymphocyte cultures stimulated by the mitogen PHA, the antigen PPD or to one-way-stimulated mixed lymphocyte cultures from unrelated donors. The results indicate that NAG (1-2 micrograms/ml) in appropriate experimental conditions has an enhancing effect on DNA and protein synthesis induced by PHA, PPD and allogeneic cells. Addition of NAG (1-2 micrograms/ml) to unstimulated lymphocyte cultures had no effect on DNA or protein synthesis.

Acetylglucosamine↗
PubMed1984

Contraception and religiousness in a general practice population in Israel.

One hundred and seventy-three Jewish women of child-bearing age attending their family doctor were asked about their contraceptive practices and attitudes. Medical means of contraception were used by 42% of the women and coitus interruptus by 44%. Although coitus interruptus is prohibited by Jewish ritual law, its use in fact applies to all age groups of women, irrespective of religiousness or family size. The small group of contraceptive pill users (17%) were younger, had smaller families and expressed a greater readiness to consider abortion in case of accidental pregnancy than the rest of the sample. They were less observant of the religious laws and might be described as 'modern' compared with the larger group of 'traditional' women. The latter preferred the intrauterine device and had larger families, but would not consider abortion, which is forbidden by Jewish law in most cases. The evidence demonstrated that the mainly traditional patients do not conform to the pattern of behaviour prescribed by their religion as closely as expected. As a result of this survey the authors are actively advocating the intrauterine device as a more effective, acceptable alternative to coitus interruptus.

Abortion, Induced↗
PubMed1984

The relationship between spinal canal diameter and back pain in coal miners. Ultrasonic measurement as a screening test?

Back pain is the commonest cause of absence among coal miners. However, the degree of morbidity is variable. To determine whether the susceptible individual can be identified, ultrasound was used to measure the spinal canal diameters of 204 miners. The results show that those men with the longest histories and the longest times off work and those who had to leave the coalface or who left the industry--i.e., those with the greatest morbidity--had significantly narrower canals. Ultrasonic measurement of the spinal canal diameter is safe and noninvasive. Its use should be further evaluated as part of a preemployment screening procedure for back pain.

Age Factors↗
PubMed1984

Elliptocytosis preceding myelofibrosis in a patient with polycythemia vera.

A patient with polycythemia vera showed marked elliptocytosis in the peripheral blood, 2 years after the diagnosis was established. 4 years later on, the patient developed myelofibrosis. The significance of elliptocytosis, which appears during the course of polycythemia vera, as an early indicator for the development of myelofibrosis is discussed.

Aged↗
PubMed1984

Therapeutic implications of viewing sexual identity in terms of essentialist and constructionist theories.

One of the most challenging developments in recent historical studies and in empirical research in sociology has been constructionist theories relating to "sexual personalities." The "constructionist" view is that sexual identity is labile and can be therapeutically modified. In clinical work, this has presented an alternative view of the development of social sex-role and sexual orientation. Previously, views of sexual identity as a fixed personal characteristic (the "essentialist" view) provided clinicians with ways of treating psychologically distressed people either by transsexual conversion or aversion therapy. This article reviews some implications of "constructionist" and "essentialist" theory. It describes the author's clinical attempts to present constructionist views to clients who are in conflict about their sexual orientation and social sex-role. The article concludes that constructionist therapy has not taken into account clinical evidence that clients may adhere to "essentialist" beliefs.

Adolescent↗
PubMed1984

Sick leave certification in general practice.

Details were recorded of all sick leave certificates issued for six months in a family practice of 1750 patients in an immigrant Yemenite working class town. Certificates were issued most on Sundays and in the autumn festive season. The common diagnoses were inflammation of the upper respiratory or gastrointestinal tracts, locomotor disorders in men and gynaecological disorders in women.

Absenteeism↗