Early nodal changes in the acute motor axonal neuropathy pattern of the Guillain-Barré syndrome.

The axonal patterns of Guillain-Barré syndrome, associated in many cases with antecedent Campylobacter jejuni infection, are now recognized as frequent causes of acute flaccid paralysis in some regions of the world. This study examined ultrastructurally the PNS of seven cases of the acute motor axonal neuropathy form of Guillain-Barré syndrome. In this disorder previous studies of advanced cases have found Wallerian-like degeneration of motor fibres in the spinal roots and peripheral nerves, with little lymphocytic inflammation or demyelination. The present study was focused on identifying early changes and establishing the sequence of changes. By electron microscopy the earliest and mildest changes consisted of lengthening of the node of Ranvier with distortion of the paranodal myelin, and in some instances with breakdown of the outermost myelin terminal loops. At this stage many nodes had overlying macrophages which extended their processes through the Schwann cell basal lamina covering the node and apposed the axolemma. Macrophage processes then extended beneath the myelin terminal loops, and the whole macrophage entered the periaxonal space at the paranode. Macrophage processes dissected the axon from the adaxonal Schwann cell plasmalemma and the macrophages advanced into the internodal periaxonal space, where they typically surrounded a condensed-appearing axon. At this stage the adaxonal Schwann cell cytoplasm regularly degenerated and disappeared, so that the periaxonal space was bounded by the innermost myelin lamella, and the axolemma of many fibres could not be seen. The internodal myelin sheath and the abaxonal Schwann cell cytoplasm remained normal. This arrangement appeared to be stable for some time, but in many fibres the axon subsequently underwent Wallerian-like degeneration. By interfering with impulse conduction, these nodal and periaxonal changes may explain paralysis in some pathologically mild cases. In addition, at early stages, these changes may be reversible, thus explaining the rapid recovery of some patients who become paralysed with acute motor axonal neuropathy. These observations, taken together with previous studies, suggest that acute motor axonal neuropathy is an antibody- and complement-mediated disorder in which the relevant epitopes are present on the nodal and internodal axolemma.

[Scanning electron microscopy of intestinal mucosa after enteric preparation in patients with carcinoma of large bowel].

In this study, 6 patients were randomly divided into three groups, receiving different intestinal preparations. Colonic mucosa were biopsied for S-520 scanning electron microscopy. Of them, only a tiny minority of bacteria were found in the specimen of the first group. Bacteria weren't discovered in the other two groups. Therefore, three conventional enteric preparations are equally effective and efficient in eliminating intestinal flora. The causes of postoperative incisional infection are many and varied.

[Labeling of granulocytic granules with RNase-gold probes].

By using ribonuclease-gold (RNase-G) probes, ultrastructural localization of ribonucleic acid (RNA) was performed in inflammatory cells from gastric mucosa biopsies of gastric cancer and gastritis, and in peripheral leukocytes from normal subjects as well as from granulocytic leukemia patients. Electron microscopically, the azurophilic granules of monocytes and lymphocytes in gastric mucosa were not labeled by RNase-G, while various cytoplasmic granules of neutrophils, eosinophils and basophils were all positively labeled. Labeling of the peripheral leukocytes from normal subjects was the same as above. It is important to find in the present study that the cytoplasmic granules of the peripheral leukemic cells from granulocytic leukemia patients were not labeled by RNase-G. The significance of the afore-mentioned findings lies on one hand in the fact that it could make a revision of the conventional views of the granular composition. On the other hand, the data indicate that the RNase-G technique is potentially explorable for future clinical utilization.

[Glucocorticoid receptor-like antigen on neuronal plasma membrane of rat brain].

The existence of glucocorticoid receptor-like antigen on the synaptic plasma membrane (SPM) isolated from rat brain was demonstrated by ABC-gold technique. The SPM was first incubated with McAb 250 (a monoclonal antibody to the glucocorticoid receptor) and then biotinylated horse-anti-mouse IgG and streptavidin-gold (SAG) was added in proper order to the reacting system. The gold particles could be visualized on the external surface of neuronal processes under electron microscope. This is the first morphological demonstration of the existence of glucocorticoid receptor-like antigen on neuronal membranes.

Human pituitary somatotroph adenoma and prolactinoma: an ultrastructural and immunoelectron microscopical study.

17 cases of pituitary somatotroph adenoma and 38 cases of prolactinoma were studied with electron microscopy and immunoelectron microscopy using protein A-gold complex. 4 adenomas were shown by immunoelectron microscopy to contain simultaneously growth hormone (GH)-producing and prolactin (PRL)-producing cells. 6 cases were classified as densely granulated GH adenomas and 11 as sparsely granulated variant, whereas only 3 adenomas out of 38 prolactinomas were identified as densely granulated adenomas. The present study showed that not all cells with fibrous bodies possessed secretory granules positive for GH, and in some cells with fibrous bodies PRL-producing granules were also detected. Misplaced exocytosis was found frequently in the sparsely granulated prolactinomas. From these findings it may be suggested that fibrous bodies are not a morphological feature characteristic of pituitary somatotroph adenomas.

[An experimental investigation on application of silver-intensification technique to immunoelectron microscopy with colloidal gold probe].

The value of silver-intensification technique to immunoelectron microscopy being displayed with colloidal gold probe was evaluated through ultrastructural study on localization of cardionatrin in the atrial cardiocytes of rat. The results indicate that this technique is simple and feasible. It enables rapid screening of positively labelled sites at low magnification, and more information will be available. Further more, it offers better contrast and this technique may be of practical value.

The promise and perils of information integration.

Integrating the four forms of information--data, text, voice and image--has been talked about for years. The computer industry has been crawling toward a solution.