Renal alterations induced by Cerastes cerastes cerastes venom.

The purpose of the present study was to determine the structural and functional alterations in the kidneys of rats experimentally envenomated with the viper Cerastes cerastes cerastes. The effects of a single i.p. sub-LD50 (0.73 mg Kg-1) for 24 hr and 7 consecutive doses (0.42 mg Kg-1; daily injection) on the kidneys of rats were studied. Histological examination of the kidneys in envenomated rats revealed the presence of atrophied glomeruli, cloudy materials within the proximal and distal convoluted tubules, atrophy and hypertrophy of quite a large number of tubular nuclei and mesangial proliferation. Hemorrhagic areas, dilated thrombosed vessels, fibrosis, and mitotic indices were also among the histopathological alterations in the renal cortex of the venom-injected animal groups. Electron microscopical findings revealed the presence of cell debris and electron dense materials within the lumen of the distal and proximal convoluted tubules. The cell lining of the proximal convoluted tubules underwent variable degrees of degeneration, and most of their intracellular organelles were deteriorated. The glomeruli contained quite large areas of mesangial matrix, and the lumen of most of their blood capillaries enclosed a moderately electron dense matrix. The cells of the endothelial lining of these capillaries were hypertrophied, and most of them lost their integrity and diffused with the surrounding matrix of the capillary lumen. Several leukocytic aggregates were observed in the intertubular spaces and blood capillaries. In addition, the erythrocytes of most of these capillaries displayed different patterns of electron density.

Fine structural changes in the ileum of mice fed on delta-endotoxin-treated potatoes and transgenic potatoes.

The present work has been designed to study the effect of feeding on transgenic potatoes, which carry the CryI gene of Bacillus thuringiensis var. kurstaki strain HD1, on the light and electron microscopic structure of the mice ileum, in comparison with feeding on potatoes treated with the 'delta-endotoxin' isolated from the same bacterial strain. The microscopic architecture of the enterocytes of the ileum of both groups of mice revealed certain common features such as the appearance of mitochondria with signs of degeneration and disrupted short microvilli at the luminal surface. However, in the group of mice fed on the 'delta-endotoxin', several villi appeared with an abnormally large number of enterocytes (151.8 in control group versus 197 and 155.8 in endotoxin and transgenic-treated groups, respectively). Fifty percent of these cells were hypertrophied and multinucleated. The mean area of enterocyte was significantly increased (105.3 microm(2) in control group versus 165.4 microm(2) and 116.5 microm(2) in endotoxin and transgenic-treated groups, respectively). Several forms of secondary lysosomes or auotophagic vacuoles were recognized in these cells. These changes were confirmed with the scanning electron microscope which revealed a remarkable increase in the topographic contour of enterocytes (23 microm in control group versus 44 microm and 28 microm in endotoxin and transgenic-treated groups, respectively) at the divulged surface of the villi. The basal lamina along the base of the enterocytes was damaged at several foci. Several disrupted microvilli appeared in association with variable-shaped cytoplasmic fragments. Some of these fragments contained endoplasmic reticulum, as well as ring-shaped annulate lamellae. In addition, the Paneth cells were highly activated and contained a large number of secretory granules. These changes may suggest that delta-endotoxin-treated potatoes resulted in the development of hyperplastic cells in the mice ileum. Although mild changes are reported in the structural configuration of the ileum of mice fed on transgenic potatoes, nevertheless, thorough tests of these new types of genetically engineered crops must be made to avoid the risks before marketing.

Ultrastructural changes in the alveolar cells of rats injected with Cerastes cerastes cerastes venom.

Ultrastructural changes in the alveolar tissue of rats intraperitoneally injected with the Cerastes cerastes cerastes venom were studied in 2 different experimental groups. In the first group, each rat was given 0.73 mg/Kg as a single dose and sacrificed after 24 hours. In the second group, each rat was given a daily dose of 0.42 mg/Kg for 7 days and sacrificed 24 hours after the last injection. Proliferative changes were seen in type II alveolar cells, fibroblasts, lymphocytes, and macrophages. Type II alveolar cells of the lungs developed a large number of surfactant granules. In the 24-hour-envenomated rats, type I alveolar cells displayed swollen nuclei and masses of dilated endoplasmic reticulum. In the 7-day-treated rats, several plasma cells, adjacent interstitial cells as well as alveolar brush cells, with their characteristic short microvilli, were detected. Large masses of collagen and elastic fibers were also located in the vicinity of the alveolar brush cells and type II alveolar cells. These histopathological changes may be attributed to the body-immune response and possibly to the development of hyperplasia due to venom-induced trauma.

Ultrastructural localization of the 9-kilodalton vitamin D-dependent calcium-binding protein in the murine intraplacental yolk sac.

The calcium-binding protein (CaBP) calbindin has been implicated in the molecular mechanism of placental calcium transfer. Previous light microscopic studies have identified CaBP in visceral (but not parietal) endodermal cells of the yolk sac with the most intense immunocytochemical signal observed in the intraplacental yolk sac. In the present studies, electron microscopy was used to study the localization of CaBP in placenta. Placentas of 17-day pregnant mice were fixed by perfusion in 0.5% glutaraldehyde, embedded in low-temperature Lowicryl K4M, and examined in thin section for specific labeling with a polyclonal antiserum. Antibody to CaBP was localized by using protein A-gold particles which were quantified for subcellular compartmentation by using a Videoplan computer system. A high signal for CaBP was found in the visceral endodermal cells of the intraplacental yolk sac. In these cells, gold particles indicating the location of CaBP were observed over 1) the cytoplasmic matrix where the average number of gold particles per micron 2 was 33; 2) the microvilli (17/micron 2); 3) the mitochondria (17/micron 2); and 4) the nucleus (43/micron 2). Sections from antigen-absorbed controls, by contrast, showed few gold particles: cytosol, 2/micron 2; microvilli, 5/micron 2; mitochondria, 5/micron 2; and nucleus, 4/micron 2. Electron-lucent profiles of the Golgi and endoplasmic reticulum contained no particles in the controls and a low particle count (4/micron 2) in the stained sections. Parietal endodermal cells of the intraplacental yolk sac showed a relatively low signal for CaBP compared with the visceral endodermal cells (5 particles/micron 2 vs. 39).(ABSTRACT TRUNCATED AT 250 WORDS)

Decidual cells in the human ovary at term: II. Morphometric analysis of cytoplasmic processes and organelles.

Morphometric analysis of human ovarian decidual cells was performed with a Videoplan computer, and mean values were established for the area and perimeter of cellular processes and organelles. Two-hundred forty electron micrographs representing 160 cells were analyzed. The mean decidual cell area was 218.7 microns2, of which 34.5 microns2 was occupied by the nucleus (15.8% of the cytoplasmic area); the nucleus contained 1.74 micron2 of nucleolar material (0.8%). The endoplasmic reticulum occupied 13.63 microns2 (6.2%). Mitochondria occupied 7.3 microns2 (3.3%) and the Golgi network 5.49 microns2 (2.5%). Decidual secretory bodies occupied 0.91 micron2 (0.42%) and cytoplasmic processes 1.89 micron2 (0.94%). The remainder of the cytoplasm, containing inclusions and cytoskeleton, represented 71% of the cell area. Perimeter measurements indicated an average decidual cell was surrounded by 87.8 microns of plasma membrane. The mean nuclear membrane measured 28.3 microns (representing 32.3% of the plasma membrane, pm, or 4.1% of total cellular membranes, cm). Outer mitochondrial membranes measured 156.6 microns (178% pm, 23.5% cm); endoplasmic reticulum membranes measured 350.3 microns (400% pm, 52.6% cm); Golgi membrane measured 30.77 microns (35% pm; 4.5% cm) and membrane surrounding secretory bodies measured 9.8 microns (11.2% pm; 1.4% cm). A mean of 280 secretory bodies per ovarian decidual cell was calculated. The plasma membranes of evaginated cytoplasmic processes represented 22.3% of the total pm (19.6 microns or 2.9% cm). A mean of seven such processes was observed per 87.8 microns of plasma membrane (160/cell). These morphometric data provide a baseline for comparisons of human ovarian decidual cells with uterine decidua, in vivo and in vitro, as well as with decidual cells of other species.