Sergio A. Bencosme

Atrial specific granules of the rat heart: light microscopic staining and histochemical reactions.

An investigation was carried out to determine general staining and histochemical properties of rat atrial specific granules. It was found that these granules may be demonstrated using aldehyde fuchsin after pretreatments which involve oxidation or thiosulfation. This new way of demonstrating atrial granules is compared to other staining methods in terms of sensitivity and selectivity as well as to the nature of reactive groups that may be involved in the staining reactions. No lipid or carbohydrate were detected histochemically. Overall assessment of reactions suggests that atrial granules are a site of storage for a protein or polypeptide. Some of the tests indicate that these may contain tryptophan and sulfur-containing amino acids.

Electron microscope observations on Langerhans cells in the cervix

Abstract Clear cells, identical in fine structure to Langerhans cells of the human epidermis, occur in the intercellular spaces of the squamous epithelium of the cervix. There is an apparent increase in the number of Langerhans cells in the cervical epithelia from cases with cardinoma in situ. Langerhans cells of the cervix are frequently mistaken for lymphocytes or for epithelial cells that have undergone cytoplasmic shrinkage. The proper identification of Langerhans cells and other clear cells in the cervical epithelium may eliminate some unnecessary confusion in the interpretation of cellular changes in neoplasia.

Diabetic capillary angiopathy in human skeletal muscles

Abstract Skeletal muscle biopsy specimens from diabetic and nondiabetic subjects were examined by light and electron microscopy. Distinctive lesions in the capillaries were found in twelve of sixteen specimens from diabetic subjects but in only three of nineteen from nondiabetic subjects. The development of the concept of diabetic microangiopathy is reviewed and discussed in relation to other vascular lesions complicating diabetes, and in relation to an abnormal response of the peripheral circulation to adrenalin infusion which has recently been described in human diabetes.

Correlative light and electron microscope study of the basement membrane of the human ectocervix

Summary Biopsies from 18 human cervices were studied by the light and electron microscope techniques in order to determine the nature of the “P.A.S.-positive basement membrane of light microscopy.” Under the electron microscope, the light microscope basement membrane was shown to be composed of connective tissue fibers (particularly reticulum fibers) in the 0.4 to 0.5 µ area of the stroma immediately subjacent to the electron microscope basement membrane. Incubation of the sections with collagenase resulted in failure of the tissue to show the “P.A.S.-positive basement membrane of light microscopy.”

Glucagon content of pancreatic tissue devoid of alpha cells.

Summary Most of the uncinate process of the dog pancreas is devoid of alpha cells, whereas these are found in the remainder. On the other hand argentaffin cells are sparsely but evenly distributed throughout the pancreas. Extracts of the portion of pancreas devoid of alpha cells show no hyperglycemic activity when 1 g aliquots are used. When 4 g portions are employed, a very mild initial hyperglycemia does occur. These findings are interpreted to support the opinion that glucagon originates from the alpha cells but are not definitive.

Alterations of Pancreas During Cortisone Diabetes in Rabbits.

Summary 1. Cortisone acetate administered intramuscularly to rabbits caused the gradual appearance of glycosuria which reached a maximum at the 5th to 9th days and then declined. Increased dosage reestablished the glycosuria but it again regressed. Morphologically, the most prominent lesion observed was ductular and centroacinar proliferation and the formation of irregularly shaped and “Mulberry” islets. In addition, numerous mitotic beta cells were observed up to 10 days after starting cortisone treatment. Similarly, degranulation of the beta cells was most prominent at early stages. Glycogen infiltration seemed to appear first in the ductular tissue and required a greater degree and duration of diabetes before affecting the beta cells. 2. The degranulation and increased mitotic activity of the beta cells are thought to be a response to hyperglycemia as is the glycogen infiltration of ducts and beta cells. The proliferative activity on the other hand is considered to represent a more direct action of cortisone on the pancreas.

Separation of Somatotrophs from the Rat Adenohypophysis by Velocity and Density Gradient Centrifugation

Summary Fractions containing over 90% somatotrophs can be separated from suspensions of adenohypophysial cells by the techniques of velocity and density gradient centrifugation. These isolated somatotrophs, as shown by radioimmunoassay, contain growth hormone. Light and electron microsopic studies show that the isolated somatotrophs retain their structural integrity. These somatotrophs incorporate 14C-amino acids into protein in linear fashion during 3-hr incubation. The expert technical assistance of Allan Morris, Oriette Morris, Margaret Evans and Blake Guggins is acknowledged.

Fine structural cytochemistry of granules in atrial cardiocytes.

Abstract Using silver methenamine technique, which selectively distinguishes between the epinephrine- or norepinephrine-containing granules of the rat adrenal medullary cells, it was found that the specific atrial granules were completely silver negative. In contrast, lysosomal granules appeared intensely impregnated with silver. It is concluded that if catecholamines are present in the atrial granules they are in a form different from that present in the cells of the adrenal medulla. It was found also that the atrial Z-lines reacted to the various staining procedures similarly to specific granules. The results of the work provide important information for further studies of differentiation of atrial granules in senescence and myopathies, since lysosomal granules increase in these conditions.

Selective Light Microscopic Demonstration of the Specific Granulation of the Rat Atrial Myocardium by Lead-Hematoxylin-Tartrazine

MacConaills lead-hematoxylin as modified by Solcia et al. was found to be a highly selective stain for the specific granulation of atrial cardiocytes in the rat. The specific atrial granules were stained blue-black. Contrast was enhanced by counterstaining in a saturated solution of tartrazine in Cellosolve. The stain is compatible with several fixatives and may be used with paraffin or Epon-embedded material.

Acute renal failure in association with fatty liver of pregnancy. Recovery after fourteen days of complete anuria.

Abstract A twenty-one year old woman with severe and prolonged renal failure associated with the acute onset of jaundice following delivery is described. The clinical, pathological and biochemical findings were consistent with fatty liver of pregnancy complicated by renal failure. The ultrastructural morphology of the renal lesion is described in detail and the changes in the glomeruli are interpreted as compatible with a lesion produced by intraglomerular fibrin formation. Such an event may have been the cause of the renal failure in this case.