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Biomedical subjects

W H CLARK

Publications and source records attributed to W H CLARK.

At least 19 recordsLinked to original sources
PubMed1960

Electron microscope studies of nuclear extrusions in pancreatic acinar cells of the rat.

This paper describes "blebs" protruding from the surface of the nucleus into the cytoplasm. The "blebs" are separated from the cytoplasm by 2 membranes which are continuous with the outer and inner nuclear membranes. The "blebs" contain 3 structurally distinct substances. Two of these substances (beta and gamma substances) are similar to extranucleolar karyoplasm and nucleolar material. The other substance (alpha substance) is present in every "bleb," but it cannot be readily compared to a recognizable nuclear structure. Cytoplasmic vesicles are described that are apparently different from the Golgi vesicles or the vesicular component of the ergastoplasm. It is suggested that these vesicles may be of nuclear "bleb" origin. A dark karyoplasmic zone extending from the region of the nucleolus into the nuclear "bleb" is shown. This zone may be similar in some respects to the preformed pathway ("Leitbahn") described by Altmann (3) and Hertl (28) and could reflect movement of nuclear material from the nucleolar region into the cytoplasm. The "blebs" are thought to be homologous to structures described by many light microscopists, but they are considerably larger than the nuclear "blebs" described previously by electron microscopists.

Acinar Cells↗
PubMed1960

Rubella arthritis. A study of twenty cases.

Twenty patients, five males and fifteen females, who had rubella arthritis were observed for periods ranging from one to ten years after recovery. Rubella arthritis in these patients was characterized by polyarthritis associated with fibrositis, myalgia, paresthesias and muscular weakness. All of the male patients but only one-third of the females had involvement of the knee joints. The small joints of the hands were the joints most commonly affected in women. Post-rubella arthritis rheumatic symptoms, especially fibrositis, persisted for many months in almost half of the females, not at all in the males. The leukocyte content of the blood tended to be low and the erythrocyte sedimentation rate accelerated in the few patients in which determinations were done.Latex tests were performed in 17 patients. Ten of the 17 were studied with the three-stage technique of Hall. Results of inhibition tests were positive in 80 per cent of the patients with rubella arthritis studied who were tested within 18 months after the onset of illness. None of the patients tested 18 months or more after rubella arthritis had positive reaction.

Arthritis↗
PubMed1959

Electron microscope studies of the human epidermis; the cell boundaries and topography of the stratum malpighii.

The thin skin of the left upper quadrant of the human abdomen has been studied by electron microscopy. Tissue removed with a high speed rotary punch was fixed in osmium tetroxide or potassium permanganate. The latter fixative in our preparations is superior to osmium for the demonstration of epidermal cell membranes and certain other membranous structures of the epidermis. The cytoplasmic membranes of basal cells and cells of the stratum granulosum have been found to be relatively straight, while those of most spinous cells are sharply scalloped. The deep cells of the stratum spinosum in the rete ridge area show cell membranes and cytoplasmic structure intermediate between true basal cells and most cells of the stratum spinosum. The extracellular material of the desmosome has been found to consist of alternate dark and light laminae similar to those described by Odland (13) and Horstmann and Knoop (7).

Cell Membrane↗