Acute glomerulonephritis. Immunofluorescent and electron-microscopic observations in sporadic cases.

The authors studied by immunofluorescent and electron microscopy renal biopsy specimens from 29 patients with various glomerular diseases. Poststreptococcal glomerulonephritis was characterized by the presence of complement (beta1C) in the mesangium and/or on the basement membrane in all cases. Immunoglobulin G (IgG) was also present in less than half of the cases in the same distribution. Electron microscopy, carried out in six cases, revealed no uniform ultrastructural change: minimal subepi helial deposits were observed in three cases, intramembranous deposits were seen in two cases, and the basement membrane was normal in one case. Glomerular abnormalities during the courses of some systemic diseases were similar. Mild renal involvement was characterized by only beta1C deposition. This finding raises the question whether a mechanism other than or in addition to that involving immune complexes is operative in the pathogenesis of acute glomerulonephritis. There is circumstantial experimental evidence that an alternate pathway of complement activation and deposition may be operative in acute glomerulonephritis.

Acute idiopathic demyelinating polyneuropathy: passive transfer to mice by immunoglobulin.

Systemic administration of acute idiopathic demyelinating polyneuropathy (AIDP) immunoglobulins to mice for two weeks resulted in reduced sural nerve action potential amplitudes and reduced (rotarod) motor performance. Electron microscopic examination of the sciatic nerves of the AIDP-immunoglobulin-treated animals revealed loosening of myelin lamellae with widening of interperiod lines and multivesicular disruption of myelin. Vacuolar degeneration was detected in half of the nerves examined by light microscopy. Injection of AIDP-immunoglobulins for three days led to only minor changes, and mice receiving healthy human immunoglobulins showed no abnormalities. These data show that some features of AIDP can be transferred to mice by systemic administration of immunoglobulins and suggest that humoral factors have a pathogenic role in AIDP in addition to cellular factors.

Cytoprotective effect of iloprost on isolated cortical brain tissue grafts in rats.

The cytoprotective effect of iloprost was studied on isolated embryonic cortical brain tissue grafts of rats, using light and transmission electronmicroscopy. The brain tissue pieces were stored either in saline or 50 ng/ml iloprost solution for 30 minutes, 3, 6, 24 hours at +4 degrees C. It was demonstrated that iloprost significantly protected the neuronal integration of the tissue pieces compared with saline preserved pieces. Tissues preserved in iloprost showed only minimal dissolution of the tissue with minimal extracellular edema only in the later stages of preservation. The mechanism of action of the cytoprotective effect of iloprost is discussed.

Neurotransmitter and amino acid analysis and ultrastructural observations of fetal brain cortex transplantation to adult rat brain under the effect of dexamethasone.

OBJECTIVE: To conduct an investigation of fetal cortical tissue graft survival using transmission electron microscopy and analyzing neurotransmitters and amino acids and their function, with special reference to the effect of dexamethasone. METHODS: Transplantation of fetal cortical brain tissue to 100 adult Wistar albino rats weighing 170 to 220 g was performed. The rats were divided into three groups. Only transplantation of fetal cortical brain tissue was performed in the first group (n=36). In the second group (n=48), dexamethasone was administered in addition to fetal cortical tissue transplantation. The third group (n=16) was used as the surgical control group. The rats were allowed to live for 6 weeks and were then decapitated. The grafts were examined by electron microscopy. Additionally, quantitative analyses of the neurotransmitters and amino acids of the grafts were conducted using high-pressure liquid chromatography. RESULTS: Electron microscopic observations revealed that the grafts were still surviving at the end of the 6th week in both groups. However, in the group that received dexamethasone, neurons and their organelles were better developed than in the group that did not receive dexamethasone. Concommitantly, results of quantitative analysis in the dexamethasone group revealed statistically extremely significant higher amino acid values for glutamic acid, aspartic acid, beta-alanine, and lysine and significantly higher values for gamma-aminobutyric acid, glutamine, glycine, and serine when compared to the nondexamethasone group. CONCLUSION: Dexamethasone is effective in increasing the survival and in developing the ultrastructural and functional outcome of transplanted neurons in fetal grafts.

Efficacy of ampicillin/sulbactam combination in experimental shunt infections caused by Staphylococcus epidermidis. A light and scanning electron microscope study.

In this study, the efficacy of ampicillin/sulbactam combination in reactions of periventricular tissue of the lateral ventricle induced by the presence of infected (Staphylococcus epidermidis) silicone rubber shunt tubing was examined by using light and scanning electron microscopy. It was demonstrated that reactive changes to implants had occurred in periventricular tissue in the control group. In infected shunt tubing without given prophylactic antibiotic group, generalized meningitis and ventriculitis, loss of integrity of ependymal cells, numerous inflammatory cells, bacterial colonies, exuda and even pus were seen. It was also shown that rarely inflammatory reactions, minimal disintegration of ependymal cells, no bacterial colonies, and phagocytes were present in the group which was given prophylactic ampicillin/sulbactam combination per and postoperatively. We think that ampicillin/sulbactam combination is very effective in prevention and treatment of shunt infections.

Fetal pituitary transplants into the hypothalamic area of hypophysectomized rats.

The pituitary tissue, when transplanted to extracerebral sites other than the normal anatomic position, fails to perform its secretory function properly. Several works on experimental intracerebral pituitary transplantation have shown that the transplanted tissue has been able to survive histologically. In this study, fetal pituitary tissue was implanted into the anterior hypothalamic area of the hypophysectomized rat by stereotactic methods. Electron-microscopic examination and hormonal blood levels demonstrated that ectopic pituitary tissue was able to survive to establish the correct anatomic relationship and thus perform secretory functions when transplanted intracerebrally.

Examination of autologous and embryonic cortical brain tissue transplantation to adult brain cortex in rats.

Autologous and embryonic cortical brain tissue was transplanted to adult rats in order to reconstruct experimentally degenerated cortical brain tissue. Rats were decapitated within 6 or 12 weeks. Viability of the graft tissues was studied by light and electron microscopy. Embryonic cortical brain tissue grafts became enlarged but adult cortical brain tissue grafts were found to be unaltered. Electron-microscopically observed mitochondria and other cell organellae and the newly vascularized areas clearly showed that the graft tissues were alive.

Improved survival of transplanted cortical brain tissue grafts by iloprost in rats.

The cytoprotective effect of iloprost on the viability and survival of embryonic cortical brain tissue grafts was examined ultrastructurally under light and electron microscopy before and 4 weeks after transplantation surgery. It was shown that neural grafts stored in iloprost solution (50 ng/mL) for 3 hours were more or less in a normal cytoarchitecture compared with saline-preserved grafts. Moreover, it was demonstrated that 4 weeks after transplantation, graft tissues stored in iloprost solution for 3 hours before implantation maintained a successful survival. Thus, a higher cellular population with new vascularization areas and preservation of myelin formation were accepted as a desirable integration of the graft tissue into the host brain tissue. The mechanism of action of iloprost is discussed.

Angiotensin-converting enzyme inhibitor cilazapril prevents chronic morphologic vasospasm in rat.

It has been shown that a long-acting angiotensin-converting enzyme inhibitor cilazapril prevents morphologic changes in arteries secondary to hypertension and endothelial damage, which are analogous to the changes in cerebral arteries following subarachnoid hemorrhage. In this study, the effect of cilazapril on chronic vasospasm was investigated on the rat femoral artery vasospasm model, and morphometric analyses were performed. Animals were divided into three groups. In group 1, femoral arteries were removed after cardiac perfusion. In groups 2 and 3, right femoral arteries were exposed to 0.1 mL autologous whole blood and wrapped with silastic cuff. Animals in group 3 received cilazapril (10 mg/kg) for 7 consecutive days. After the perfusion-fixation, femoral arteries were examined by light and transmission electron microscopy and processed for morphometric analysis. Vessels from animals in group 2 showed a significant luminal narrowing and morphologic changes throughout the vessel wall, while vessels from animals treated with cilazapril appeared nearly normal. These results suggest that cilazapril may be effective in the prevention of chronic vasospasm.

A case of Whipple's disease complicated by fatal hepatitis.

Whipple's disease was diagnosed in a 42-year-old woman by the histological examination of a mesenteric lymph node taken at laparotomy, and the electron microscopic examination of a peroral intestinal biopsy specimen. She responded well to tetracycline therapy, but succumbed to fatal hepatitis ten weeks after the diagnosis of Whipple's disease

Suppression of atherogenesis by n-3 fatty acids in the cholesterol-fed rabbit.

The effects of n-3 fatty-acid supplementation on serum lipids, platelet aggregation, and the development of atherosclerotic lesions were studied in the cholesterol-fed rabbit. Serum total cholesterol and LDL cholesterol values were significantly reduced in comparison with those of the nonsupplemented cholesterol-fed group (p less than 0.005, p less than 0.0025, respectively), though still higher than those of the control group (p less than 0.0025, p less than 0.0125 respectively). Platelet aggregation was reduced below that of the cholesterol-fed and the control levels (p less than 0.0005, p less than 0.0025, respectively). The endothelial injury encountered in cholesterol-fed rabbits was inhibited in the supplemented group. It is concluded that n-3 fatty acids suppress atherogenesis in this animal model by interfering with platelet aggregation and lipid metabolism.

Ultrastructural investigations on the degenerative and regenerative processes in chorda tympani in bell's paralysis.

Our ultrastructural findings in investigated cases of Bell's palsy have demonstrated that the degenerative changes did not proceed at the same speed from the onset of the paralysis--in other words the regeneration changed in accordance with the topography of the nerve. Although the endoneural sheath preserved its integrity, swellings in the Schwann cells have attracted much attention. Furthermore the perineural tissue presented changes which were closely correlated with the degenerative and regenerative processes due to paralysis. In addition to these findings, although the interval between the onset of paralysis and the operation was the same in all our cases, the observation of a more severe degenerative picture of the nerves in the female patients may seem to be an interesting finding, but to the lack of an adequate number of cases which would enable a statistical evaluation, we are strongly, of the opinion that this subject deserves further study.

Ultrastructural findings of the nasal mucosa of "ozaena" in atrophic rhinitis.

Alterations in the nasal mucous layer of atrophic rhinitis "Ozaena" patients have been investigated. The vast majority (99%) of these patients were women. Morphological findings in healthy nasal mucosa demonstrated the different functional stages of the glandular tissue cells with the healthy epithelium. On the other hand, nasal mucosal material taken from the patients displayed prominent epithelial deterioration, decrease in and loss of cilia, increase in goblet cells with squamous epithelial metaplasia. A decrease in secretory granules and membrane deterioration in the apical region of the secretory cells was also clearly visible. It is possible to postulate that the ultrastructural changes seen in the secretory and storage cycles of glandular tissue of the nasal mucosa from patients seem to arise as a reaction to the superficial epithelial deterioration of the nasal mucosa together with the resulting deterioration of physiological conditions.

Congenital insensitivity to pain with anyhydrosis: morphological studies of skin and peripheral nerves.

Two male siblings born to consanguineous parents, with the diagnosis of congenital insensitivity to pain with anhydrosis are evaluated. The patients presented with unexplained bouts of fever, self-mutilation, repeated trauma and inability to sweat. Physical examination revealed both siblings to be insensitive to pain and temperature. The electron microscopic study of the skin was unremarkable whereas sural nerve biopsies yielded an essential lack of unmyelinated fibers.

Ultrastructural observations on the entry of Chlamydia trachomatis into human spermatozoa.

Chlamydia trachomatis infections are an important problem in human reproduction and family planning. In this study, the significance of chlamydial infection in male infertility and artificial insemination has been investigated. Electron microscope observations on male ejaculates have revealed the presence of the elementary and reticulate body forms of C.trachomatis in spermatozoa. Furthermore, the entry of the elementary body into the human spermatozoon head has been demonstrated. After the passage of the infectious elementary body into the nucleus, all stages of reticulate body formation in the head of the spermatozoon were detected. According to ultrastructural findings, C.trachomatis not only adhered to but also penetrated into the tail structure. Thus two different functional and morphological forms of C.trachomatis can infect and be transmitted by spermatozoa and may cause infertility.

Some new findings about Hofbauer cells in the chorionic villi of the human placenta.

The cytological structure of the Hofbauer cells was investigated in human placentas of the first and second trimesters of gestation. These cells are found in the stromal channel system of the chorionic villi core. Their walls, which are supported by collagen fiber bundles, are produced by reticulum cells and fibroblasts. The cytoplasmic processes of the Hofbauer cells are in contact with the walls of the channels without being associated with them by desmosomal complexes. Some of these cells have features in common with macrophages, such as cytoplasmic processes, larger vacuoles, many pinocytotic vesicles and intracytoplasmic granules. This system of vacuoles and vesicles enables micropinocytotic activity and phagocytosis. This type of Hofbauer cell resembles the typical macrophages. These cells may play a role in the regulation of stromal water content, transportation of ions and the flow of interstitial fluid. The most original finding of this study are long tubes observed in some Hofbauer cells and extending between the nucleus and the extracellular ground substance through the cytoplasm. One of these tubular formations resembles a cilium in structure with three limiting membranes and is filled with a slightly electron-dense substance. This type of Hofbauer cell may transport information between the nucleus and the extracellular ground substance by means of these tubular structures.

Reaction of rabbit lateral periventricular tissue to non-infected and infected (Staphylococcus epidermidis) shunt tubing implants. A light and transmission electron microscope study.

The reactions of periventricular tissue of the lateral ventricle to non-infected and infected (Staphylococcus Epidermidis) silicone shunt tubing were examined by light and transmission electron microscopy. It was shown that reactive changes occurred in periventricular tissue in response to the implant of sterile shunt tubing. On the other hand in infected implanted silicone shunt tubing, proliferation of inflammatory cells within the ventricle and periventricular tissue, loss of integrity of the ependyma, glial cell proliferation, and excessive extracellular oedema were demonstrated. Proliferation of ependymal cells combined with inflammatory responses may be a factor in the pathogenesis of infected shunt obstruction.

Behçet's disease associated with amyloidosis in Turkey and in the world.

The association of amyloidosis with Behçet's disease has infrequently been reported in published works. Twenty four such cases have been observed in the world, of which 12 are from Turkey, including eight of ours. In all our eight cases renal biopsy showed amyloidosis of type AA. Behçet's disease of male preponderance, long duration, complete type, multiple organ involvement, and positive skin pathergy test were the main characteristics of all 24 cases of Behçet's disease with amyloidosis. We conclude that amyloidosis associated with Behçet's disease is a secondary AA amyloidosis occurring as an intrinsic manifestation of Behçet's disease.

Preventive effect of intracisternal heparin for proliferative angiopathy after experimental subarachnoid haemorrhage in rats.

Proliferative angiopathy represents the morphological basis of delayed cerebral vasospasm. The initial vasoconstriction and endothelial damage of the vasospastic arteries leads to an exaggerated response of the smooth muscle cells within the media leading to subintimal thickening and myonecrosis. Heparin reduces the exposure of the media to platelet derived growth factor, a mitogen from aggregating platelets responsible for the migration and proliferation of the myofibroblasts. Since systemic heparin in the setting of a subarachnoid haemorrhage would be unacceptable, we have tested the effect of heparin on proliferative angiopathy by injecting autologous non-heparinized blood into two groups of rats (N = 12 each) and then inject the heparin into the spinal fluid of one group after one hour. We were able to show histologically that intracisternal heparin injection after the subarachnoid haemorrhage has reduced the vascular wall changes to a great degree. Heparinization of the cerebrospinal fluid carried out in conjunction with early operation for aneurysms may be a promising approach to prevent the morbid complications of SAH in the clinical setting.

Fetal vasculogenesis and angiogenesis in human placental villi.

Placental villi of 5 exactly defined early human specimens ranging from day 21 post conception (p.c.) until day 42 p.c. and from an additional 43 specimens from about 5 to 40 weeks menstrual age have been analyzed ultrastructurally with regard to fetal vasculogenesis and angiogenesis. The following results were obtained: The first cells differentiating at day 21 p.c., probably originating from mesenchymal precursors, are macrophage-like cells. At almost the same time, mesenchymal cells transform into haemangioblastic cell cords which are the forerunners of the capillary endothelium and haematopoietic stem cells. A third cell population related to the fetal circulatory system and derived from the mesenchymal cells are presumptive pericytes. Capillary formation takes place by the aggregation of haemangioblastic cells which are attached to each other by intercellular junctions. The lumen is formed by the dehiscence of the intercellular clefts. A capillary basal lamina cannot be detected earlier than in the last trimester. In this last period of gestation, fetal villous angiogenesis takes place by the proliferation of the existing endothelium and pericytes rather than via haemangioblastic cells.