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In an Italian kindred (family N), early onset Alzheimer's disease has been transmitted in a Mendelian autosomal fashion since the early 18th century. The age at death of affected members of the family varies widely, and was taken as an index of the age of expression, a measure of phenotypic variability. Either a gamma or a log-normal algorithm provides the best fit for the age at death distribution. Subsets of family N widely different as to time and place have the same age at death of patients: Environment appears to play a negligible role in the expression of disease. Pairwise correlation between an affected parent and child is zero: The disease is monogenic (no major expression gene). The same stochastic distribution of age of expression, but with late onset, and after correction for death from other causes, is compatible with the epidemiology of Alzheimer's disease in general. Mendelian genetics is a possible model for Alzheimer's disease etiology. (J Geriatr Psychiatry Neurol 1992;5:126–131). [ABSTRACT FROM PUBLISHER]

It has been shown that micro-injections of angiotensin II in the Organum cavum pre-lamina terminalis (OCPLT) of the rat brain trigger water intake. Our anatomical study shows that the anterior, vertical extension of this Organum corresponds to the anterior inter-hemispheric fissure, and its posterior, horizontal extension to the Cavum septi pellucidi (CSP). Contrary to classical descriptions, the CSP persists in the adult rat, though reduced to one third of its initial antero-posterior extension. It appears rostrally as an opening into the anterior inter-hemispheric fissure. The absence of ependymal cells and of communication with the lateral ventricles points to the fact that this diverticulum is not a median cerebral ventricle. Its pial sheathing and the presence of leptomenix in the cavity confirm its inter-hemispheric origin. The pinocytotic vesicles of the meningeal capillaries suggest an active transfer of substances. Circumstantial evidence suggests circulating angiotensin could be one of them.

The data of 2049 patients, who underwent maxillofacial orthopaedic surgery, were retrospectively analysed for major intra- and immediate postoperative complications. Immediate life-threatening complications were very rare. They can in most cases be avoided by good anaesthetic and surgical techniques and adequate postoperative care. The most frequently encountered problem in maxillary surgery is excessive blood loss, whilst a compromised airway due to swelling is the most frequent complication in mandibular surgery. Good co-operation between anaesthetist and surgeon is essential to prevent major intraoperative and immediate postoperative problems.

A 23-year-old woman experienced headache following a high thoracic epidural analgesia to control postoperative pain after thoracoscopic treatment of a recurrent pneumothorax. On fourth postoperative day, a blood patch has been sited with 17 mL of autologous blood, injected into the thoracic epidural space at T1-T2 level, which was immediately effective. Except a mild and transient cervical pain during the procedure, no other complication occurred. The technique of thoracic blood patch is similar to the lumbar one, except some minor modifications. According to this case of a thoracic epidural blood patch which is seemingly the first one reported in the literature and our expertise with two other unpublished cases, a volume of 10 mL of blood may be sufficient and free of adverse effects.

At the transition between central nervous system (CNS) and peripheral nervous system (PNS), the CNS compartment forms cone-shaped incursions into the peripheral part of the dorsal root. The ultrastructural study of the CNS-PNS transitional zone shows that this region is particularly rich in astrocyte processes. In an attempt to investigate the possible role of the CNS-PNS interface astrocytes in myelin formation, a photonic microscopy immunocytochemical study has been done with anti-GFAP and anti-MBP sera. The CNS glial expansion shows an important GFAP immunoreactivity with intimate association between astrocyte processes and myelinated axons. This may indicate that the transitional myelin originates from astrocytes. The same region is also MBP-positive. Two explanations are considered: some astrocytes form transitional myelin sheathes and express MBP epitopes, or oligodendrocytes, with cell bodies distant from the CNS-PNS interface, send myelinating cytoplasmic expansions which are not shown by the techniques we used.

A histological and cytological study of stimulated and non-stimulated bovine lymph nodes was performed using immunocytochemistry and electron-microscopic techniques. Immunohistochemical staining using polyclonal antibodies revealed cytoplasmic immunoglobulins producing lymphoid cells. A protein S100 specific serum evidenced antigen presenting cells, macrophages and endothelial cells. In order to identify T lymphocytes, two monoclonal antibodies (M1 and M12) were used. The electron-microscopic study confirmed the localization and identification of different lymphoid and non-lymphoid cells of the lymph node. The techniques used in the present work seem to be suitable for investigating bovine lymph nodes and those with pathologic alterations.

Paired Helical Filaments (PHF), as demonstrated at the ultrastructure level, are one of the main pathological landmarks of Alzheimer's disease (AD). A polyclonal rabbit antiserum raised against PHF had been shown to label tangles and the periphery of plaques at the light microscope level. The same antiserum labels PHF specifically at the ultrastructure level, as demonstrated with a postembedding immunogold technique. Normal cytoskeleton constituents and plaque amyloid were not labelled. Specific labelling of a characteristic landmark may be a clue for a biological marker of AD.

Newborn rabbits were exposed 18 hours a day for 6 weeks to an intense electric field; then they were killed, the body weight and the weights of the main organs had the same values as the control ones. The compositions of liver and interscapular brown fat were not modified. There was no significant effect of the electric field either on plasma levels of ACTH, GH, T3, T4, corticosterone, cortisol or on plasma levels of glucose, triglycerides and cholesterol. The histology of thyroid and adrenals showed no evident alterations. Ultrastructural examinations of the cerebellum did not show the previously described alterations observed in Purkinje nerve cells. It is concluded that in the present experimental conditions, the chronic exposure of newborn rabbits to an intense electric field did not modify the biological and structural parameters which were examined and had no effect on the animal growth and development.

Acoustic neurinomas are vestibular schwannomas. Ultramicroscopic examination of the root of these tumors, removed using a petrosal approach (translabyrinthic, suprapetrosal) in 20 cases, investigated the site of origin of the schwannoma. Tumoral capsule was absent between Scarpa's ganglion cells and tumoral cells, these two types of cells being intermingled. The fact that the very small tumors, 3 to 5 mm in diameter, were all derived from Scarpa's ganglion and were separated by a capsule from the other structures of internal auditory canal prove that acoustic neurinoma arises from Scarpa's vestibular ganglion. Other studies have shown the absence of myelin surrounding bodies of Scarpa's ganglion cells in humans, inversely to findings in other vertebrates. Since on the one hand the appearance in humans is similar to that observed during development of Scarpa's ganglion in the rat, and on the other hand acoustic neurinoma has never been demonstrated in the animal, it can be suggested that acoustic neurinoma development in humans corresponds to cellular immaturity of Scarpa's ganglion.

The origin of eighth nerve neurinoma has been studied by several authors with the light microscope, particularly on serial sections of decalcified temporal bone. The microsurgical approach of small neurinomas has led the present authors to an ultrastructural study of this problem. In the cases in which the origin could be seen, the tumor appeared to arise from the ganglion vestibulare (Scarpae). This fact is correlated with the neural crest origin of the ganglion, and with its ultrastructural characteristics in the normal human.

The ganglion vestibulare (Scarpa) has been studied with the electron microscope on thirteen operative specimens (neurectomy for Meniere's vertigo) and two random autopsy specimens. Neuroganglionar cell bodies are enclosed in a Schwann sheath, without any myelin. This observation is at variance with previous descriptions in various vertebrate forms.

Small acoustic neuromas, operated on through transpetrosal approaches were studied by light and transmission electron microscopy. All schwannomas were found to interpenetrate the vestibular ganglion without a space or a capsule. In the abnormal ganglion areas, free tumour Schwann cells were observed. These results suggest that acoustic neuromas originate from the vestibular ganglion. The fact that the sheath of vestibular ganglion bipolar cells in man are devoid of myelin may account for the elective origin of acoustic neuromas in the Scarpa ganglion in the human.

The sheath of the bipolar perikarya of the vestibular ganglion (Scarpa) in Papio papio is made up of several Schwann cells which concur to form loose myelin, and at most five layers of compact myelin. Most of the Schwann cytoplasmic layers stop at the emergence of both neurites, forming at the point an incomplete Ranvier half-node. The constitution of the vestibular perikaryal sheath in Papio is intermediate between those previously described in the Rat and in the Human.