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Biomedical subjects

A Nielsen

Publications and source records attributed to A Nielsen.

At least 91 records · Page 5Linked to original sources
PubMed1982

An autoradiographic study of cell kinetics in epidermis of the toad Bufo bufo bufo (L).

Under normal conditions, the toad Bufo bufo bufo molts about once a week. It was considered of interest to study whether the rhythmic pattern of cell loss through shedding of a stratum corneum is correlated with a rhythmic production of cells in stratum germinativum. An autoradiographic investigation of cell kinetics in toad skin using [3H]-thymidine and [14C]-thymidine as precursors revealed that cell production in stratum germinativum is a continuous process, and the cell production rate is much higher than is required for replacement of the cells lost with each molt. The parameters measured, i.e., % labeled cells, length of cell cycle, and S-phase, as well as migration of labeled cells from stratum germinativum toward stratum corneum support the assumption of an inhomogeneous cell population in stratum germinativum. A model proposed by Potten form the cellular organization of mouse epithelium provides a useful basis for the interpretation of the results obtained in the present study.

Animals↗
PubMed1982

Medical students' evaluation of psychiatry: a cross-country comparison.

The authors reviewed studies of attitudes toward psychiatry held by 368 medical students at the University of California, Los Angeles (UCLA), and 204 senior medical students from two schools in Washington, D.C. They found that the attitudes of all these students were remarkably similar: they viewed psychiatry as a worthwhile medical specialty but one of low prestige and low precision and thought that most psychiatric patients could be adequately managed by non-physicians. On the basis of their findings the authors offer recommendations for teaching basic psychiatric skills and for improving psychiatry's image and attractiveness.

Attitude↗
PubMed1981

The value of 99mTc-cholescintigraphy as compared with infusion cholecystography for diagnosing acute cholecystitis.

A prospective comparative study was made of 99mTc-HIDA cholescintigraphy and 24-h infusion cholecystography for the diagnosis of acute cholecystitis. The material comprised 50 patients. Non-visualization of the gallbladder was regarded as a positive result and as indicative of acute cholecystitis. The final diagnoses were made at operation (36 patients), by additional examinations (9 patients), by a typical clinical course (3 patients), and at autopsy (2 patients). The predictive value of a positive and a negative cholescintigraphy was 92.6% and 95.7%, respectively. The predictive value of a positive and a negative infusion cholecystography was 78.6% and 81.8%, respectively. There was no statistically significant difference between the results of the two tests. The 99mTc-HIDA cholescintigraphy was easier and quicker to perform than the cholecystography, and likewise the scintigrams were easier to assess than the infusion cholecystograms. The diagnostic certainty of cholescintigraphy was found to be high, and the test is recommended in patients suspected of having acute cholecystitis.

Acute Disease↗
PubMed1980

Growth curves of three human malignant tumors transplanted to nude mice.

Experimental growth data for three human malignant tumors transplanted to nude mice of BALB/c origin are analyzed statistically in order to investigate whether they can be described according to the Gompertz function. The aim is to set up unequivocal standards for planned therapeutic experiments and to develop an essential part of the determination of proliferation parameters for the tumors. The results indicate that the course of tumor growth can be described with good approximation by the Gompertz function. A transformation of this function depicts the growth rectilinearly and appears to be suitable as a standard, e.g. in therapeutic experiments. The course of tumor growth is independent of the size of the transplant, and whether tumors are transplanted in the right or left or both flanks of the recipient mice. Furthermore, the growth does not vary in a systematic way with the number of passages in nude mice. For tumors whose growth is described according to the Gompertz function, recording of the growth of the tumor size in two dimensions is sufficient for calculating other relevant growth parameters, if the three linear tumor measurements are proportional throughout the growth period. The initial histological development of a transplanted malignant melanoma is described and used to elucidate other tumor growth measurements.

Adenocarcinoma↗
PubMed1979

Squamous cell carcinoma of the skin and internal malignant neoplasms.

This study comprised 211 patients in whom squamous cell carcinomas of the skin (SCC) had been diagnosed in the Department of Dermatology from 1950 to 1959. These patients were followed up as of Jan 1, 1976, to establish the incidence of internal malignant neoplasms. A systematic statistical study was carried out through the population register, the central register for death certificates, and the Danish Cancer Register. These registers cover the entire country, making it possible to calculate the number of expected cases of internal cancer during the above-mentioned prolonged period of observation. The investigation did not show increased incidence of internal malignant neoplasms in connection with SCC of the skin.

Adult↗
PubMed1979

Psychosocial aspects of truancy in early adolescence.

The authors studied truancy in junior high school students, largely by structured interviews of 33 truants. Truancy at this age was commonly associated with significant difficulties at home, at school and with peers. Two modal types of truants were delineated: "authority defying" and "peer phobic." The school environment, including the response to truancy and the transition to the junior high, was found to play a critical role in creating and aggravating truancy. The authors discuss the findings with respect to strategies for prevention and remediation.

Absenteeism↗