Growth hormone releasing factor: comparison of two analogues and demonstration of hypothalamic defect in growth hormone release after radiotherapy.

Human pancreatic growth hormone releasing factor (hpGHRF(1-40] stimulates the release of growth hormone in normal subjects and some patients with growth hormone deficiency. A study comparing the shorter chain amidated analogue hpGHRF(1-29) with an equivalent dose of hpGHRF(1-40) in seven normal subjects showed no significant difference in growth hormone response between the two preparations. Six patients with prolactinomas were also tested; these patients had received megavoltage radiotherapy previously but had developed growth hormone deficiency as shown by insulin induced hypoglycaemia. In all six patients 200 micrograms hpGHRF(1-40) or hpGHRF(1-29)NH2 produced an increase in the serum growth hormone concentration. These data suggest that hpGHRF(1-29)NH2 may be useful for testing the readily releasable pool of growth hormone in the pituitary and that cases of hypothalamo-pituitary irradiation resulting in growth hormone deficiency may be due to failure of synthesis or delivery of endogenous GHRF from the hypothalamus to pituitary cells.     

Fine structure of dense-cored vesicles in glomus cells of rat carotid body after fixation with permanganate or glutaraldehyde

Summary Glomus (Type I) cells of the carotid body of adult rats were studied electron microscopically after fixation with potassium permanganate or with glutaraldehyde and osmium tetroxide. Two permanganate fixation methods (using Krebs-Ringer-glucose, pH 7.0, or acetate buffer, pH 5.0) were compared. Numerous dense-cored vesicles were observed only in about one tenth of the glomus cells when neutral permanganate was used for fixation, although all glomus cells showed such vesicles after fixation with glutaraldehyde and osmium tetroxide. Numerous vesicles with a dense core were observed in about one third of the cells after fixation with acid potassium permanganate. With this fixation, small dense-cored vesicles similar to those in adrenergic nerve terminals were occasionally seen in the cytoplasm of glomus cells. It is tentatively concluded that the amine-storing vesicles of the carotid body are different from those in the small intensely fluorescent (SIF) cells and those in adrenergic nerve terminals.     

The light microscopic demonstration of hydroperoxidase-positive Phi bodies and rods in leukocytes in acute myeloid leukemia

Summary Unique fusiform or spindle-shaped particles (Phi bodies) and rods with hydroperoxidase (catalase and/or peroxidase) activity are present in human granulocyte precursors only in acute myelogenous leukemia (AML). These newly recognized particles are much more numerous and prominent than Auer rods. They may be rapidly and readily identified using the microscope in marrow or peripheral blood films when the procedures recommended in this paper for fixation, incubation for hydroperoxidase demonstration in 3,3-diaminobenzidine (DAB)/H₂O₂ medium, copper salt treatment and counterstaining (optional) with the Papanicolaou method are employed. Films prepared in the same manner but treated with benzidine/H₂O₂ medium for myeloperoxidase did not reveal these particles.We believe that Phi bodies are pathognomonic of AML since they are almost invariably present in AML patients with active disease. Their presence serves to distinguish AML from acute lymphocytic leukemia and from chronic granulocytic leukemia in blast crisis. Since the particles disappear in disease remission and reappear upon relapse, the recommended procedure is not only useful in diagnosis but in guiding therapy.When a very rapid diagnosis is needed, it is not necessary to counterstain the preparations, but the nuclei, cytoplasm and plasmalemma can readily be observed in the granulocyte precursors when they are counterstained by the Papanicolaou method. This treatment does not diminish the clarity of the Phi bodies and rods which stain by virtue of their peroxidatic activity.This cytochemical diagnostic procedure should be considered for adoption by hematology laboratories.This investigation was supported by NIH research grants DE02668, CA11265, DE04730, and RR05333     

Light and Electron Microscopic Observations of Gametogenesis in Hastigerina pelagica (Foraminifera)*

SYNOPSIS. During gametogenesis mother individuals of Hastigerina pelagica (d'Orbigny) undergo significant morphological changes. Thirty h before gamete release, the cytoplasm changes from pale orange to bright red, possibly due to transport of stored lipids from the inner region to more peripheral parts of the cytoplasm. During the next 10 to 15 h the bubble capsule which surounds the calcareous shell is discarded. After all bubbles have disappeared, the individual sheds its spines by resorbing the spine bases close to the shell surface. A single mother nucleus divides into some hundreds of thousands of gamete nuclei within a span of ～ 20 h. A bulge of cytoplasm is extruded from the aperture and increases in size during the next 5 to 10 h. This bulge consists of cytoplasmic strands in which gametes and spherical bodies are embedded. The gametes and spherical bodies mature and are released during the afternoon and early evening. The gametes have 2 unequal acronematic flagella. A previously undescribed structure in foraminiferal reproduction is the spherical body which consists of a large vacuole surrounded by a thin cytoplasmic layer in which several nuclei, various typical cell organelles and multiple flagella are present. The spherical bodies are believed to play a role as receptacles of waste material, possibly including residual digestive enzymes, thereby protecting the gametes from lysis during the reproductive process. Fusion of gametes and further development into the next generation have not been observed.     

A photomap of the salivary gland chromosomes of Anopheles stephensi liston (Culicidae: Diptera)

A photomap of the banding pattern of the salivary gland chromosomes of Anopheles stephensi Liston, which is first of its kind, has been prepared. The salivary chromosome complement consists of five arms, the shortest of which represents the telocentric X-chromosome, and the remaining four the autosomal arms. A comparison has been made of the banding pattern of this species with other species of the subgenus Cellia.