Aging and Alzheimer's disease: protease inhibitors in cerebrospinal fluid.

Recent advances suggested that proteases and their inhibitors could be implicated in the genesis and/or maturation of insoluble deposits associated with Alzheimer's disease (AD). This study was designed to measure the level of alpha 1-antichymotrypsin (ACT) and alpha 1-antitrypsin (AT) in cerebrospinal fluid (CSF) of patients with AD and nondemented humans at various ages. Our analysis failed to demonstrate a significant relationship between inhibitor content and disease. However, a positive correlation was observed between age and the ACT level for the normal control group. Such observation suggests a specific association of ACT with the mechanisms of brain aging.

A new monoclonal antibody recognizing the amino-terminal consensus sequence of vertebrate intermediate filament proteins.

The mouse monoclonal antibody ME 101 raised against human peripherin, an intermediate filament protein (IFP) specific to well defined neuronal populations, recognizes all the major classes of vertebrate IFP in immunoblotting assays. Desmin, GFAP, vimentin, peripherin and the lightest neurofilament protein (NF-L) were cleaved into carboxy- and amino-terminal halves by N-chlorosuccinimide at their unique trytophan residue. Whereas the antibody directed against the epitope common to every IFP (intermediate filament antigen or IFA) and located on the carboxy-terminal end of the rod domain recognizes the carboxy-terminal half, the ME 101 antibody, as the present study illustrates, recognizes specifically the amino-terminal half. From the amino acid sequence data of IFP, it is deduced that the cognate epitope is localized on the amino-terminal part of coil la.

Abnormal expression of actin in lymphocytes of Alzheimer's disease and Down's syndrome patients.

Alzheimer's disease (AD) is a degenerative disorder of the central nervous system accompanied by several immunological disturbances and a number of common features exist between AD and Down's syndrome (DS). High resolution two-dimensional electrophoresis of lymphocyte proteins demonstrates an actin abnormality in AD and DS: a double actin spot instead of the single spot observed in controls. This dual form was studied by pulse-chase experiments and seems to be related to extracellular factors which influence the post-translational modification of actin. These results agree with the immunological disturbances observed in AD and DS, and with the well established hypothesis that AD is a systemic as well as cerebral disease.

Biodegradation and brain tissue reaction to poly(D,L-lactide-co-glycolide) microspheres.

The therapeutic application of neuroactive molecules in neuroscience is limited, due to the problems posed by the administration of these drugs (peripheral metabolism, systemic effect and passage of the blood-brain barrier). One solution is the implantation in the brain of biodegradable polymer devices with controlled release of a neuroactive drug. The biodegradation and tissue reaction of the copolymer poly(D,L-lactide-co-glycolide) microspheres prepared by the solvent evaporation method, radiosterilized and stereotactically implanted in the rat brain were studied by routine staining, immunohistochemistry and transmission electronic microscopy. The brain tissue reaction observed was a non-specific astrocytic proliferation and a macrophagous-microglial cell reaction, typically found following damage to the central nervous system. Some foreign-body giant cells were observed and the inflammatory and macrophagous reaction decreased dramatically after 1 month and almost ended after 2 months when the microspheres were totally biodegraded. The copolymer poly(D,L-lactide-co-glycolide) microspheres may be considered biocompatible to the brain tissue.

Somatostatin and adrenocorticotrophic hormone like immunoreactivity in small cell carcinoma of the lung.

The immunocytological detection of adrenocorticotrophic hormone (ACTH) and somatotropin release inhibitor factor (SRIF) like immunoreactivity was carried out on tumour cells from bronchial brush smears in 39 cases of lung tumours. Results obtained were compared with the cytological and histological diagnosis and confirmed the high incidence of ACTH synthesis by malignant bronchial carcinoma cells: the same phenomenon also seems to occur for somatostatin. The concomitant detection of ACTH and SRIF like immunoreactivity seems to be highly suggestive of small cell carcinoma and indicates that the immunocytological detection of hormones carried out at the same time as cytological examination can improve the accuracy of the diagnosis.

A single intracerebral microinjection of platelet-derived growth factor (PDGF) accelerates the rate of remyelination in vivo.

We had demonstrated that platelet-derived growth factor (PDGF) enhanced the reconstruction of myelin-like membranes after their disruption by lysophosphatidylcholine (LPC) in vitro. To investigate its role in vivo, a demyelinating lesion of the corpus callosum was induced in adult Wistar rats by a stereotaxic microinjection of 1 microl LPC, then 63 pairs of rats received either 1 microg PDGF, or its vehicle buffer which were injected above LPC. The effects of PDGF were significant after 2 weeks: the number of oligodendrocytes (OL) expressing 2',3'-cyclic nucleotide 3'-phosphodiesterase in the lesion increased by 49%, mature OL labelled by in situ hybridization for myelin basic protein-mRNA increased by 27% (P<10(-2)), and the total volume of demyelination decreased by 60% compared to controls. The proliferation of cells of the OL lineage was also enhanced up to 67% by PDGF compared to LPC controls (P<2.5 x 10(-2)). Ultrastructural studies confirmed this dramatic improvement, and the ratio of remyelinated to demyelinated axons, determined at the maximal demyelination site, in the centre of the lesion, increased by 10-fold (P<2.5 x 10(-3)) in animals treated with PDGF. Remyelination was complete after 3 months for both treatments. Neither exacerbation of gliosis nor glial tumoural transformation were observed. Mechanisms through which PDGF improves remyelination could involve proliferation of OL progenitors, and/or of already differentiated surviving OLs, and a chemotactic effect, which had been identified in vitro.

Lipopolysaccharide intracerebral administration induces minimal inflammatory reaction in rat brain.

An inflammatory reaction, essential for defence against infection and for wound repair, may also induce irreversible tissue damage. It appears that the central nervous system has developed its own immunosuppressive strategy in order to limit the destructive effects of inflammation. To clarify this point, we have characterized in one unique model of inflammation induced in the rat by intracerebral lipopolysaccharide injection the kinetics of the inflammatory reaction, the participation of immunitary and glial cells and of three growth factors. Among these molecules, brain-derived neurotrophic factor mRNA expression was found decreased following LPS injection. No striking differences were observed in the brain parenchyma after stab lesion or inflammatory lesion apart from an increase in the number of monocytes/macrophages recruited early to the lesion area. Macrophages were later accumulated around the lesion when astroglia and microglia reactions occurred. Some of the macrophages and microglia expressed major histocompatibility complex class II antigens on their surface whereas no T or B lymphocytes were observed in the brain parenchyma. However, a subpopulation of CD3- and CD4-negative CD8-positive cells, likely natural killer cells, was observed around the lesion site; this recruitment was inhibited by the highest dose of LPS. This study therefore supports the hypothesis of a suppression of some aspects of cell-mediated immunity in the brain, mechanisms which need to be further characterized.

Pure Schwann cell suspension grafts promote regeneration of the lesioned septo-hippocampal cholinergic pathway.

Regeneration of central nervous system (CNS) axons has been studied in the cholinergic septo-hippocampal system using various 'bridges' able to support fiber growth. In this study, a pure Schwann cell (Sc) suspension labeled with bisbenzimide (Hoechst 33342) was grafted in the lesioned septo-hippocampal pathway. At 2 weeks post-grafting, acetyl-cholinesterase (AChE)-positive fibers invaded the graft and grew in association with the Hoechst-labeled Sc, some of which expressed the low-affinity nerve growth factor receptor (NGF-R). At 2 months and 4 months post-grafting, the dorsal hippocampus was reinnervated with an apparently normal innervation pattern. Analysis of fiber growth in the hippocampus at four months post-grafting revealed a significant increase of reinnervation in the grafted animals (2 mm) compared to the non-grafted ones. No difference was observed in the number of cholinergic septal neurons expressing the NGF-R. These results demonstrate that a Sc suspension grafted into the lesioned septo-hippocampal system, integrates well into the host tissue, and supports axonal CNS outgrowth, implying that Sc by themselves provide an adequate environment for regeneration to occur.

Differential behaviour of PC12 cells grafted into rat hippocampus and striatum.

To investigate the mechanisms involved in graft survival, a rat cell line (PC12) that differentiates into sympathetic-like neurons by exposure to trophic factors has been grafted into rat striatum and hippocampus, two structures which differ in their amounts of trophic factors. Our results show that grafted PC12 cells behave differently depending on the area of implantation; they display a differentiated morphology in the hippocampus and proliferate as a tumor in the striatum. A qualitatively similar immunological reaction occurs in both structures, characterized by the invasion of T and B lymphocytes, macrophage-like cells and by the expression of major histocompatibility complex class I and II antigens around the graft.

n-6 polyunsaturated fatty acids increase the neurite length of PC12 cells and embryonic chick motoneurons.

We have tested the action of three n-6 polyunsaturated fatty acids, either free or in the form of ethyl esters, on the neurite outgrowth in two neuronal models: a rat pheochromocytoma cell line (PC12) and embryonic chick motoneurons, after 7 days in culture. An inverted microscope coupled with the 'VIDS 4' software was used for measuring the neurite length. Free fatty acids were found to be cytotoxic at 10(-3) M and the maximal increase of the neurite length was obtained at 10(-5) M. In contrast, fatty acids in the form of ethylesters were not cytotoxic and at 10(-3) M induced the maximal increase in the neurite length. This increase (1.2 to 2 fold) significantly differed from the control and was dose-dependent. These results were discussed in relation to the action of fatty acids on enzyme activation and membrane fluidity.

Autoantibodies against H- and M-subunits of neurofilaments are induced by PC12 cell grafts or lesions into different sites of rat brain.

Since autoantibodies against neurofilaments (NF) were frequently found in neurodegenerative disorders, this work is an attempt to investigate whether the same phenomenon occurs after intracerebral grafting or lesioning. We have thus either grafted PC12 cells or injected culture medium alone into three sites of rat central nervous system (CNS): olfactory bulb (OB), olfactory anterior nucleus (OAN) and hippocampus (HC), all three sites being impaired in Alzheimer's disease. At day 15, rat sera were collected and tested against NF by western blotting. Sera from grafted rats recognized the H- and M-subunits of NF; we have then quantified the autoantibody response by using an ELISA technique. We show that, in all cases of grafts, the autoantibody response against NF significantly increased when compared to controls (normal rats without grafts or lesions) for total immunoglobulin (Ig) amount. In contrast, concerning the Ig isotypes, some differences appeared depending on the implantation site: for grafts into OB, the immune response was of both the IgG and IgM isotypes, into OAN it was mainly of the IgM isotype and into HC, the isotype of antibodies against NF was mostly IgG. In the case of lesions alone into OAN and HC, no significant enhancement of autoantibody response was observed; in contrast, lesions into OB induced an increase in autoantibody response against NF which significantly differed from controls for all Ig isotypes tested. These data point out the diversity of the autoantibody responses following lesions or grafts according to the rat brain areas.

Hepatocyte-derived cell lines express a functional receptor for cardiotrophin-1.

Cardiotrophin-1 (CT-1) is a recently isolated cytokine belonging to the interleukin-6 cytokine family. In the present study, we show that CT-1 binds to hepatocyte-derived cell lines of rat and human origin with high (Kd = 600-800 pM) and low (Kd approximately 3-6 nM) binding affinities. Treatment of HepG2 cells with CT-1 resulted in the induction of tyrosine phosphorylation of both transducing receptor subunits, gp130 and LIF receptor, and this phosphorylation was completely inhibited by a neutralizing anti-gp130 mAb. Addition of CT-1 to HepG2 or H35 cell cultures induced a dose-dependent production of several acute phase proteins (haptoglobin, fibrinogen, alpha1-acid glycoprotein, alpha2-macroglobulin). Moreover, the use of a neutralizing mAb to gp130 in cultures of HepG2 cells grown in the presence of CT-1, inhibited the induction of acute phase protein secretion, indicating an absolute requirement of gp130 in the formation of a functional CT-1 receptor. Altogether, these results suggest that CT-1 could play an important role in the regulation of hepatocyte metabolism in inflammatory responses.

Intravascular malignant lymphomatosis (so-called malignant angioendotheliomatosis): a case confined to the lumbosacral spinal cord and nerve roots.

Intravascular malignant lymphomatosis (IML), so-called malignant angioendotheliomatosis, was found in lumbosacral spinal cord and nerve roots of a 78-year-old women who died one month after the onset of symptoms. With regard to the majority of the 37 reviewed neurological cases in the literature, this report is unusual in that the disease was exclusively localized in the spinal cord and systemic involvement was absent. The usual clinical hallmark of the disease is a subacute dementia or encephalopathy, often associated with focal neurological signs, culminating in death within several months. The pathological features of IML characteristically include multiple small foci of necrosis of the whole brain, caused by occlusion of small vessels by noncohesive neoplastic cells and secondary changes of the vascular wall. All organs may be involved, especially the skin and the adrenals, sometimes with tumoral formations. Despite the fact that lymphoid tissues are usually spared, recent reports and the present case strongly suggest a lymphoid rather than endothelial origin of the malignant cells. The pathogenesis of this mainly intravascular lymphoma remains obscure.

[Polyneuropathies with IgM monoclonal gammopathy. 12 cases]. / Polyneuropathies avec gammapathie monoclonale IgM. 12 cas.

12 cases of polyneuropathy with IgM monoclonal gammapathy are reported. An analysis of the clinical, electrophysiological, histological and immunological features of these cases and of those reported in the literature allows to distinguish 2 groups. In the first group (8./12 cases), the neuropathy showed clinical and electrophysiological features of a mainly demyelinating mechanism involving large fibers. Electromicroscopy disclosed a widening of the spaces between the lamellae of the myelin in half of these cases. A monoclonal deposit of IgM was demonstrated by direct immunofluorescence, on the remaining myelinated fibers in most cases. In this first group, the M-component always reacted with the myelin sheaths of a monkey's peripheral nerve. The results of indirect immunofluorescence were closely correlated with those of immunoblotting, which revealed an anti-M.A.G. (Myelin Associated Glycoprotein) activity. The second group is more heterogeneous: there was an predominantly motor neuropathy (1 case), an asymmetrical and painful neuropathy with an endoneural deposit of IgM (1 case). In 2 other cases which in no other ways differed from those of the first group, the M-component seemed devoid of antimyelinic activity. Nevertheless, the presence of IgM on the myelin sheaths of these 2 cases suggested a relationship between the neuropathy and the gammapathy. In both groups, results from the association of apheresis and chlorambucil were difficult to assess and vary greatly. Therapy appeared beneficent in half of the cases, but only one patient was markedly improved.

[Chronic encephalitis with mesencephalic predominance. A clinico-pathologic case]. / Encéphalite chronique à prédominance mésencéphalique. Un cas clinico-pathologique.

A 70 year-old woman presented with a progressive supranuclear ophthalmoplegia, with "apraxia" of eyelid opening, axial akinesia and dementia. CT scan showed a mild cortico-subcortical atrophy and there was a high level of immunoglobulins, with an oligoclonal pattern, without cell reaction in the CSF. The patient died two years after the onset. Post-mortem examination, limited to CNS, showed subacute encephalitis confined to the tectal, pretectal, subthalamic areas and to Ammon's horns. These changes and their location were strongly suggestive of polioencephalomyelitis with or without cancer, in which such a prevalent midbrain involvement has been exceptionally described.

[Clinico-pathologic case of slowly progressive herpes simplex encephalitis without temporal necrosis]. / Un cas clinico-pathologique d'encéphalite herpétique lentement progressive sans nécrose temporale.

A case of herpes simplex encephalitis (HSE) is reported. The patient experienced short term memory disorders and irritability progressing over 3 months, without seizures or fever. The CSF was normal. CT showed a small low density area in the right posterior orbito-frontal region. At post-mortem examination, one month later, the temporal cortex appeared largely spared by necrosis, which involved the posterior orbito-frontal areas. Cowdry type A inclusions, herpes virus like particles and fluorescent reaction with HSV1 monoclonal antibodies strongly supported the diagnostic. Such atypical cases of long duration have apparently seldom been reported. They suggest that HSE should be considered in the differential diagnosis of a subacute encephalopathy.

[Intracerebral grafts in Parkinson's disease]. / Les greffes intracérébrales dans la maladie de Parkinson.

Although the beginnings of neural transplantation can be traced back to the last century, this technique was not fully developed until the 1970's. Following an experimental stage, considered insufficient by some authors, the first neural grafts on humans were performed in Parkinsonians in 1982. One must, in fact, distinguish between two types of operation, each with its own ethical and scientific problems. The first operation is human embryonic neural transplants the effects of which are related to a real reinnervation of the striatum. The other operation consists of autografts of adrenal medulla, which still have hypothetical modes of action. The first results obtained in man with both types of operation are rather disappointing. Even though neuronal grafting is unquestionably a technique of the future, much caution must be exerted since intracerebral grafting in Parkinson's disease remains at the experimental stage.

[Complications and biological risks of neuronal grafts]. / Complications et risques biologiques des greffes neuronales.

Following an experimental stage, considered insufficient by some authors, the first neural grafts on humans were done on Parkinson patients in 1982. Since then, hundreds of patients, mostly with Parkinson disease, have been subjected to grafts. Recently patients suffering from other neurodegenerative diseases or pain of carcinomatous origin have also been grafted. The first results obtained in humans are modest and vary depending on the research groups and methods employed. It must be distinguished between two types of surgery which raise different ethical and scientific problems. First, embryonic neural transplants, in which the effects could be related to a possible actual reinnervation of the striatum. Second, autografts of adrenal medulla, the mechanisms of action of which are still hypothetical. The relative ease of graft technique and their success with the media should not minimize complications and risks. There are three types of known or possible complications: 1 - the complications related to the surgery, 2 - the non-specific complications of the graft itself, that are secondary to the host reaction to transplantation, 3 - the specific graft complications related to relationship established between the grafted cells and the host. In the adrenal medulla autograft, the surgery complications are responsible for an important morbidity and mortality. The immunological and infectious (viral) risks are the most worrying in the embryonic transplants. Even though neuronal grafting can be a technique of the future, great caution is necessary, since intracerebral grafting in Parkinson's disease still is in the experimental field.

[Olfactory mucosa and Alzheimer's disease. Technique for biopsy and ultrastructural study]. / Muqueuse olfactive et maladie d'Alzheimer. Technique biopsique et étude ultrastructurale.

The discovery of a reliable peripheral marker would be of a great interest for the early diagnosis of the Alzheimer's Disease. The olfactory deficit and the major histologic changes of the olfactory-related areas of the brain occurring during this disease raised the possibility that the olfactory epithelia could be one of the way of entry of a possible process that still has to be identified. We have developed an instrument and a technique of biopsy of the human olfactory mucosa to search for the presence of characteristics lesions on patients suffering of an Alzheimer's Disease. These small specimens have been prepared for electronic microscopy. The ultrastructural study of a sample of olfactory mucosa has been realised in 9 cases (5 Alzheimer's-4 controls) revealing in 4 patients suspected of an Alzheimer's Disease a complete architectural disorganisation with a destruction of the dendrite of the olfactory cells and a severe degeneration of the sustentacular cells. We did not find any characteristic changes such as Paired Helicoidal Filaments or amyloid fibrils. These results do not presuppose of their eventual presence at a precocious stage of the disease. Further ultrastructural and immunochemical studies carried out with patients at various stages of the disease are necessary in order to confirm this hypothesis.

[Intracerebral graft of a line of chromaffin cells. Immunologic aspects and role of nerve growth factor in survival and differentiation of the graft]. / Greffe intra-cérébrale d'une lignée de cellules chromaffines: aspects immunologiques et röle du nerve growth factor dans la survie et la différenciation du greffon.

The efficiency of neuronal grafts is correlated with the differentiation of the grafted cells and the connections they establish with the host tissue. The prolonged survival of a chromaffin cell line (PC12) transplanted into an immunodepressed rat brain shows that neuronal differentiation is correlated with the amount of nerve growth factor (N.G.F.) present in the grafted structure. This result is in agreement with in vitro studies. The characterization of other factors that influence the differentiation of PC12 cells in culture could lead to an increase in the efficiency of intracerebral grafts of adrenal medulla cells in Parkinson's disease.