Biomedical subjects
Publications and source records attributed to V Grouls.
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A trichoblastic fibroma in the oval fossa of the left thigh of a 70 year old female is described. Basaloid cell complexes were surrounded by a moderately cellular, partly fibromyxoid stroma. Epithelial buds resembled the primitive hair germ which derives from the embryonal periderm. Epithelial layers, 1-2 cells thick, were enclosed in a hyalinized and condensed stroma. The development of a real hair bulb or a real hair matrix was not found.
The present study has focused mainly on microenvironmental aspects of the thymus from a 17-year-old female patient suffering from myasthenia gravis. The most striking lightmicroscopic feature was again the well known presence of lymphoid follicular hyperplasia. Ultrastructurally, the configuration, cellular composition and fine structure were to a large extent the same as in other, peripheral lymphoid organs. Cells showing the typical morphologic characteristics of fibroblastic reticulum cells, which are most probably precursors of dendritic reticulum cells, were observed within germinal centers. Additionally the morphology of the unaffected medulla and corticomedullary region was studied, thereby paying particular attention to the structural changes of interdigitating cells. These contained frequently Birbeck granules, which have not been described before in human thymus.
The leukemic infiltrate in the liver in hairy cell leukemia may be easily overlooked in conventional histological slides and an exact classification may not always be possible. In order to facilitate the identification of tricholeukocytes , it is suggested to perform the tartrate-resistant acid phosphatase stain on routinely formalin fixed and paraffin-embedded liver biopsy specimens. Thereby it will be in most cases possible to demonstrate sufficiently enough enzyme activity to establish unequivocally the diagnosis of hairy cell leukemia.
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To obtain more information concerning the origin of interdigitating cells, the postnatal development and morphology of the periarteriolar lymphatic sheath in splenic white pulp of rats was investigated by light- and electron-microscopy. Special attention was paid to the ontogeny of interdigitating cells. The spleens of the animals were studied in the age range from 1 h to 28 days after birth. The splenic white pulp of neonatal rats consists only of a few reticuloblasts, which are concentrically arranged around central arterioles. After 21 h an increase in promonocytes and monocytes was noted. Between the fifth and seventh postnatal day monocytogenic cells with a light and almost translucent cytoplasm appear, which display long cytoplasmic projections between the adjacent cells. Neighbouring lymphocytes often insert finger-like processes into the invaginated cellular membrane of these transitional forms. This intimate cellular contact is supported by zonulae occludentes. These cells represent transitional forms between monocytes and interdigitating cells. From seven days of age onwards typical interdigitating cells were present as in adult animals. After the differentiation into an inner and outer periarteriolar lymphatic sheath, the T-cell-dependent area of splenic white pulp has attained its adult appearance and further changes are not to be expected. On the basis of these findings, it is highly probable that interdigitating cells develop via transformation of monocytes.
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A combined nevus occurring on the right temporal region of a 30-year-old man with multiple giant pigmented nevi on the head, trunk and extremities was surgically removed. Histologically, the cellular blue nevus found in the deep corium fulfilled the criteria of malignancy in so far as mitoses and foci of tumor necroses were present.
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Autoradiographic investigations on kidney cells were performed after focal cryolesions (-180 to -196 degrees C) and focal heat application (740 degrees C). Cells were studied 12 h to 30 days after the lesions had been produced. In the damage granulation tissue the percentage of radioactively labelled fibroblasts as well as the percentage distribution of leucocytes, monocytes, macrophages, lymphocytes, fibroblasts and fibrocytes and the mean cell concentration were determined. There were no significant differences in the leucocytic and monocytic cell reactions after the two types of physical injuries. However, the percentage of fibroblasts, fibrocytes and macrophages was higher and the percentage of lymphocytes lower after cryonecrosis when compared to heat application. The cell concentration increased during the last 2 weeks of the experimental time after a thermolesion. The labelling index of the wound fibroblasts was significantly higher after the 10th day after thermonecrosis than after in sinus freezing. The increased cellular activity 2 to 4 weeks after heat coagulation of the kidney was probably induced by the delayed resorption of the carbonised necrotic tissue. The reduced phagocytic activity of macrophages might have depended on alteration and modification of molecular cell structures which were different after heat application of freezing. The different lymphocytic reaction seems to be the consequence of different immune responses of the lymphatic system. It is suggested that focal thermolesions may have a stimulatory effect on the cell-mediated immune response and that focal cryonecrosis may induce an increase in humoral immune response.
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The use of Congo red as an elective stain for eosinophilic granulocytes and their precursors in tissue sections and autoradiographs is demonstrated and discussed. The 0.5% alcoholic Congo red solution of Highman, normally used for the detection of amyloid, may also be used with only minor changes. This simple method may aid in the diagnosis of special hematological problems and facilitates the recognition of eosinophil granulocytes as well as proliferating and nonproliferating myelocytes in autoradiographs from paraffin sections.
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Age-dependent changes in splenic megakaryocytopoiesis of Wistar rats, 1 hour to 60 days old, were investigated using autoradiograms of semi-thin sections. The highest values for 3H-thymidine labeling and mitotic indices were observed immediately after birth, whereas the maximal concentration of megakaryocytes was seen on the 14th day after birth. The transit time of megakaryocytes in newly born rats was 34.5 hours and, thus, much shorter than in adult animals.