Pathomorphology of the kidneys in hemolytic-uremic syndrome in children

The kidneys were studied morphologically in 64 cases of hemolytic-uremic syndrome (HUS) in children aged from 17 days to 4 years. Three variants of the kidney alterations are distinguished depending on the duration of acute renal failure (ARF): early, late and delayed alterations. Early alterations were observed if ARF lasted for 1-10 days and were characterized by glomerular thrombotic microangiopathy with disturbance of the nephron proximal part function resultant from microcirculatory damage. Late kidney alterations (11-20 days of ARF) consisted of glomerular thrombi fibrinolysis, development of mesangial cell proliferation and mesangiolysis, proximal tubular epithelium regeneration and the appearance of nephrohydrosis resulting from the distal nephron part obstruction by hyalin cylinders. Delayed alterations (21-62 days of ARF) manifested with predominant atrophic and sclerotic processes. The first variant corresponded to the acute course of HUS while the two last variants to the subacute one.     

Helicobacter pylori and stomach cancer]

The neoplasms and gastric mucosa colonization with Helicobacter pylori was studied in 40 stomachs resected for expansive (n = 20) and infiltrative (n = 20) carcinoma using Giemsa staining histological sections, histochemical reactions to oxyreductase, and urease test. In expansive carcinoma of the stomach, H. pylori was identifiable both in the tumour and surrounding gastric mucosa in 70 per cent of cases; infiltrative carcinoma appeared to be associated with gastric mucosa H. pylori in 80 per cent, whereas tumour H. pylori were recordable in 30 per cent of cases, which fact is dependent upon the histological structure of carcinoma. The role H. pylori plays in cancerogenesis is discussed.     

Dose-dependent inactivation of extracellular human immunodeficiency virus by miramistin

BACKGROUND: There is a need for an atraumatic, fast, reliable, inexpensive, reversible-on-demand method for female sterilization which is also free from side-effects. The use of an Nd:YAG laser for occlusion of human fallopian tubes in vitro was assessed for achieving these aims. METHODS: An in vitro study was performed on coagulation of fallopian tube tissue using continuous wave Nd:YAG laser. Posthysterectomy human uteri were exposed to laser radiation either directly through an optical fibre or through a sapphire contact probe at the ostia at different laser powers and inter-action times. RESULTS: Laser-induced tissue coagulation plugged the ostia in a clean, controlled and predictable manner. Microscopic examination of the coagulated tissue showed about 50 microns wide blind holes without any continuous channel; thus eliminating the possibility of passage of sperms through such a plug. The depth of coagulation along the lumen of the fallopian tubes increased linearly with the interaction time of the laser beam at a constant power, either by direct irradiation or through a contact probe. The maximum depth of coagulation was found to be about 3 mm in case of direct irradiation at a laser power of about 6.5 W and interaction time of 50 seconds. Beyond these values, charring occurred at the surface of the tissue. CONCLUSION: Nd:YAG laser might be a suitable means for female sterilization. Further studies in experimental and clinical settings would be required to confirm its utility.     

Histogenesis and diagnostic of kidney cancer in the light of electron microscopic data

Electron microscopic examinations of human renal carcinoma showed that both light and dark (granular) differentiated tumour cells may have ultrastructural features of the cells of any nephron segment. In the light of these results and concepts of the capacity of undifferentiated tumour cells for specific differentiation, the decisive importance in histogenesis (cytogenesis) of the renal carcinoma belongs not to the site of its origin in one or another nephron segment but to the level of differentiation of stem cells (polypotent or monopotent) undergoing malignization and to the direction of their further differentiation. The paper presents concrete ultrastructural differential diagnostic features of renal carcinoma cells.     

Presence of cross-reacting thymus and brain antigens in the cerebral cortex

Rabbit antisera against antigens of mouse, rabbit, guinea pig and human whole brain cross-reacted in the cytotoxic test with the lymphocytes of the thymus, lymph nodes and the spleen of these animal species. Mouse thymocytes were most sensitive to the antibrain sera (cytotoxic index -- 63--100 per cent); cells from other mouse lymphoid organs and lymphocytes of rabbit, guinea pig and man were more resistant. Bone marrow lymphocytes were not damaged by any of these sera. The antigens which induced the cytotoxic properties of the sera were found only in the human cerebral cortex, but not in the white matter of the brain stem.     

Electron-microscopic radioautography of DNA-synthesizing cells of growing rat smooth muscle tissue

DNA-synthesizing cells of rat stomach muscle tissue following 50% resection of the fundal part, identical cells of the vena cava after disturbance of the blood out flow, and of the appendix on contraction of the ascending part of the large intestine were studied by electron microscopic autoradiography. DNA synthesis in the differentiated myocyte nuclei of the stomach muscle tissue, and of the "activated" myocytes of the stomach and the vein was observed. There were signs of asynchronous DNA synthesis in the nuclei of some smooth muscle cells and fibroblasts.