Ultrastructural studies of glycoconjugates in brain micro-blood vessels and amyloid plaques of scrapie-infected mice

Summary Lectin or glycoprotein-gold complexes and samples of scrapie-infected mouse brain embedded in Lowicryl K4M were used for ultrastructural localization of glycoconjugates. The lectins tested recognize the following residues: -D-galactosyl [RCA,Ricinus communis agglutinin (aggl.) 120], N-acetyl and N-glycolyl neuraminic acid (LFA,Limax flavus aggl.), N-acetyl-D-glucosaminyl and sialyl (WGA, Wheat germ aggl.), N-acetyl-D-galactosaminyl (HPA,Helix pomatia aggl., and DBA,Dolichosbiflorus aggl.), -D-mannosyl/-D-glucosyl (Con A, Concanavalin A), -D-galactosyl and -D-galactopyranoside (BSA,Bandeirea simplicifolia aggl., izolectin B₄). Labeling of the majority of micro-blood vessels (MBVs) located outside the plaque area and in the remaining cerebral cortex was similar to that which has been previously observed in non-infected animals. Some MBVs, however, located inside the plaque area and surrounded directly by amyloid fibers showed attenuation of the endothelium, the surface of which was scarcely and irregularly decorated with RCA, LFA, WGA and Con A. These abnormalities in the composition of glycoconjugates can be associated with previously noted increased permeability of some MBVs in the brains of scrapie-infected mice. Some vessels in the plaque area were encapsulated by perivascular deposits of homogenous or flocculogranular material containing several glycoconjugates. A very intimate structural relation between reactive (microglial-like) cells and amyloid fibers suggests the participation of these cells in elaboration of plaque material. Labeling of the cell surface and adjacent amyloid fibers with the same lectins (RCA, WGA, DBA, Con A) suggests the possibility that the glycosylation of these fibers occurs extracellularly. Only WGA and DBA were occasionally labeling some Golgi elements of the reactive cells.Supported in part by a grant from NINCDS No. 17271-06     

Ultrastructural localization of lectin receptors on cerebral endothelium

Summary Oligosaccharide residues on the endothelial luminal plasma membrane of rat cerebral cortical vessels were localized using biotinylated lectins. In addition, the effect of pretreatment of brain slices with neuraminidase prior to the binding of cationized ferritin (CF) and certain lectins was studied.Conjugates of biotinylated lectins and avidin-d horseradish peroxidase reaction product were evenly distributed on the endothelium of arterioles, capillaries, and venules. Lectin binding sites were observed on the plasma membrane of pinocytotic vesicles open onto the vascular lumen and at the luminal end of the interendothelial space only. The following sugar residues were localized: -d-mannosyl, -d-glucosyl, -N-acetylglucosaminyl, sialyl,d-galactosyl, -l-fucosyl, and -N-acetyl-d-galactosaminyl.Following pretreatment of brain slices with neuraminidase -d-gal-(1–3)-d-galN-acetyl groups were demonstrated on endothelium. In this respect, cerebral endothelium differs from noncerebral endothelium which is reported to have peanut agglutinin binding sites without neuraminidase pretreatment.Anionic groups on cerebral endothelium were demonstrated at the same locations as the lectin binding sites. Following neuraminidase pretreatment there was reduction, but not absence, of CF binding supporting the observation that surface charge is not wholly due to sialyl groups.The role of monosaccharide residues in states of altered cerebrovascular permeability remains to be determined.Supported by Ontario Heart Foundation grant no. 2-6     

Lectin histochemistry of plaques and tangles in Alzheimer's disease

Summary Biotinyl derivatives of several lectins and avidin-horseradish peroxidase were used to study the localization of glycoconjugates in amyloid plaques and in neuritic tangles in brains of patients with Alzheimer's disease (AD), Downs syndrome (DS) and Gerstmann-Sträussler syndrome (GSS). The lectins tested recognize the following residues: -d-galactosyl [Ricinus communis agglutinin 120, (RCA-1) and peanut agglutinin, (PNA)]; -d-galactosyl [Griffonia simplicifolia agglutinin (GSA)]; -d-mannosyl>-d-glucosyl [concanavalin A (Con A) andLens culinaris agglutinin (LcH)];N-acetyl- andN-glycolylneuraminic acid [Limax flavus agglutinin (LFA) andLimulus polyphemus agglutinin (LPA)];N-acetyl-glucosaminyl and sialyl [wheat germ agglutinin (WGA)];N-acetyl-d-galactosaminyl [Helix pomatia agglutinin (HPA) andDolichos biflorus agglutinin (DBA)] and -l-fucosyl [Ulex europeus agglutinin (UEA-1)]. The majority of lectins listed above bind preferentially to the peripheral area of AD plaques, whereas in plaques of DS they are mainly bound to central amyloid core. In neurofibrillary tangles of AD brains only residues recognized by WGA and HPA or DBA were found, whereas in DS brains, in addition to above mentioned, -d-galactose (RCA-1) and sialic acid (LFA) were also present. In brain microblood vessels the strongest reaction in endothelia appeared with UEA-1 and RCA-1, indicating the abundance of -l-fucosyl and -d-galactosyl residues. In AD brains deposits of amyloid were noted in the wall of some blood vessels, where monosaccharide residues recognized by RCA-1, GSA, UEA and WGA but not by Con A and LFA were present. However, our studies of some organs (liver, kidney, heart and testes) of patients with generalized amyloidosis revealed a lack of these sugar residues. It indicates, that the composition of amyloid present in brains of AD is different to that in other organs in generalized amyloidosis.Supported in part by grant no. AG 04220-03 from the National Institute of Aging, NIH     

Effect ofd,l-α-aminoadipate on the mediobasal hypothalamus and endocrine function in the rat

Summary Using the glutamate analog,d,l--aminoadipic acid (d,l-AA), experiments were conducted to examine the nature, extent, and specificity of its toxicity in the mediobasal hypothalamus and to determine its effect on endocrine homeostasis. Neonatal rats received daily injections ofd,l-AA (4 g/kg BW) on postnatal days 5–10 and were killed at various post-treatment intervals. Sex-matched littermates were given equimolar amounts of NaCl and served as controls. Treated rats killed 18 days post injection weighed slightly less than controls and had reduced testicular, ovarian, and uterine weights, but the differences were not statistically significant. Ind,l-AA treated rats serum and pituitary levels of TSH and PRL were comparable to control values. Pituitary content of LH ('s and 's) and FSH ('s), however, was lower (P<0.05) ind,l-AA treated rats than in controls, but serum levels were not significantly different. Distinct cytopathologic changes were evident in the arcuate nucleus and median eminence ofd,l-AA-treated rats killed at 2 and 6 h post injection only. By 12 h evidence of acute damage had largely disappeared. Both glial and ependymal cells underwent edematous swelling and necrosis, but neurons were largely unaffected. Evidence of reactive changes, such as gliosis, infiltration of microglia, and removal of debris, however, were not very conspicious. A random sample of mediobasal hypothalami of rats killed 18 days post injection failed to show any detectable lesion or residual effects of earlier pathology. Age at the time of exposure to the gliotoxin was found to be an important variable affecting both extent and duration of injury. The most deleterious effects were observed when the gliotoxin was administered in the form of a single injection on postnatal day 5 only. The results suggest that normal neuronal activity and endocrine homeostasis, specifically gonadotropin, may be irreversibly altered as a consequence of transient disruption of the glial compartment.Supported by grants from the Medical Research Council of Canada, the St. Boniface General Hospital, and Mrs. James A. Richardson Research Foundations     

Cerebral endothelial plasma membrane alterations in acute hypertension

Summary This study was undertaken to localize oligosaccharide residues on the endothelial luminal plasma membrane of cerebral vessels of normotensive animals and vessels permeable to horseradish peroxidase (HRP) in angiotensin-induced acute hypertension. Wistar-Furth rats were injected with HRP intravenously and hypertension was induced by an intravenous infusion of angiotensin amide. Animals were fixed 2.5, 10 and 15 min later and the HRP reaction product was demonstrated in brain slices, followed by lectin localization using the avidin-biotinperoxidase method. Oligosaccharide residues demonstrable on the luminal plasma membrane of cerebral endothelium of normotensive controls and both permeable and nonpermeable vessels of hypertensive animals were: -d-mannosyl, -d-glucosyl, -N-acetylglucosaminyl, sialyl, -d-galactosyl, -l-fucosyl and -N-acetyl-d-galactosaminyl groups. Peanut agglutinin did not bind to the endothelium of normotensive controls or of nonpermeable vessels in hypertensive animals, but did bind to endothelium of vessels permeable to HRP 2.5 min after the onset of hypertension. At 10 min, the luminal plasma membrane of vessels regained their normal characteristics and peanut agglutinin binding was no longer demonstrable. Our studies suggest that increased cerebrovascular permeability to protein in acute hypertension is associated with loss of the terminal sialic acid groups on the luminal plasma membrane of permeable vessels. This results in the observed reduction of charge on the endothelium and an exposure of -d-gal-(1,3)-d-gal N-acetyl groups leads to binding of peanut agglutinin. Both alterations are rapidly reversible and no longer demonstrable 10 min after the onset of hypertension, when blood pressures reach resting levels and the blood-brain barrier is restored.Supported by Heart and Stroke Foundation of Ontario Grant 2-6     

αB-Crystallin is present in reactive glia in Creutzfeldt-Jakob disease

Summary -Crystallin is a major eye lens protein, composed of two types of subunits, A and B. The A subunit is restricted to the lens, but B-crystallin has recently also been detected in non-lenticular tissues, including the nervous system. With the use of a polyclonal antiserum directed against a synthetic C-terminal peptide of human B-crystallin, the presence of B-crystallin could be demonstrated immunohistochemically in astrocytes in the brains of patients with Creutzfeldt-Jakob disease (CJD). Most intensive localization was observed in the spongiotic tissue representing abundant progressively changed astrocytes in CJD. In agematched control brains weak positive reaction was located in individual oligodendroglia cells and subpial astrocytes. Prominent increase of B-crystallin in pathological glia in CJD may represent a response to stress.     

Dose-dependent pharmacokinetics of α-methyl-p-tyrosine (α-MT) and comparison of catecholamine turnover rates after two doses of α-MT

Summary Groups of rats were injected i.p. with 0.407 or 1.02 mmoles/kg of D, L--methyl-p-tyrosine methylester HCl (-MT). The time-courses for-MT in plasma and brain were followed together with the endogenous brain dopamine (DA) and noradrenaline (NA) contents.The elimination of-MT from plasma and brain was markedly delayed after the high-MT dose compared with the low dose. At 40 hours after the injection of 1.02 mmoles/kg of-MT both plasma and brain levels were high, whereas no-MT could be detected in plasma or brain at 16 hours after the lower dose.The brain catecholamines were decreased to very low values after the higher-MT dose (DA 14% and NA 10% of controls at 8 and 24 hours respectively). There was no complete recuperation at 40 hours of any of the amines. After the lower-MT dose, the DA concentration was back to control levels at 16 hours and NA at 12 hours. Between 16–40 hours after the high-MT dose a majority of the rats showed prominent signs of sedation, weight loss and dehydration. No such signs were observed in rats receiving 0.407 mmoles/kg. During the first hour after the-MT injection the declines of DA and NA respectively were almost identical for both-MT doses. When the whole time-course (0–8 hours) after the high dose was considered, biphasic declines were obtained for both DA and NA, suggesting at least two different catecholamine pools. However, due to toxic effects after the high-MT dose, turnover data have to be interpreted with caution.     

Ganglioside mapping of a human medulloblastoma xenograft

Summary The ganglioside patterns of medulloblastomas have never been established; in this study we report the ganglioside profile of the human medulloblastoma cell line TE-671 grown as a xenograft in nude mice. Gangliosides were isolated and structurally analyzed by fast atom bombardment mass spectometry following permethylation. Identification of individual gangliosides was also performed by immunostaining of high-performance thin-layer chromatography-separated bands. Total ganglioside levels of 0.20 mol/g of tissue were obtained, consistent with those reported for human glioma cell lines grown as xenografts; predominant monosialogangliosides of TE-671 xenografts were II³--NeuAc-LacCer (GM3) and II³--NeuAc-GgOse₃ Cer (GM2) but there were also relatively large proportions of IV³--NeuAc-LcOse₄Cer (3-isoLM1), IV³--NeuAc-nLcOse₄Cer (3-LM1) and a further ganglioside of the neolactoseries with an extra lactosamine moiety. The only oligosialoganglioside detected was IV³, II³--NeuAc₂-GgOse₄Cer (GD1a).Abbreviations: The gangliosides have been designated according to Svenerholm [18] GM3 II³--NeuAc-LacCer - GM2 II³--NeuAc-GgOse₃Cer - GM1 II³--NeuAc-GgOse₄Cer - 3-LM1 IV³--NeuAc-nLcOse₄Cer - 3-isoLMI IV³--NeuAc-LcOse₄Cer - Fuc-3-isoLMI IV³--NeuAc, III⁴-Fuc-LcOse₄Cer - GD1a IV³, II³--NeuAc₂-GgOse₄Cer - FAB-MS Fast atom bombardment-mass spectometry - GC-MS gas chromatography-mass spectometry Supported by NC1 RO1 CA11898 to Dr. Bigner and B8803X-00627-24B from the Swedish Medical Research Council to Dr. L. Svennerholm     

Immunoglobulin heavy chain gene associations in myasthenia gravis: new evidence for disease heterogeneity

Summary Susceptibility to myasthenia gravis (MG) is known to involve genes residing in the major histocompatibility complex class I and II regions (HLA-B8 and DR3). Immunoglobulin heavy chain constant region (IgCH) allotypes have also shown some associations with MG. We have used restriction fragment length polymorphism analysis with probes to the IgCH switch (S) regions and 1 and the downstream marker D14S1 to investigate 189 Caucasoid patients with well-defined MG. A highly significant increase in the frequency of the 2.6 kilobase (kb) S homozygous genotype and the 2.6 kb S allele was found in patients with disease onset after the age of 40 years (late onset) compared with normal controls (P<0.00075 andP<0.025 respectively). No association was found at the S1 or D14S1 loci. In patients with an associated thymoma there was a moderate increase in the frequency of the 2.6 kb S and 7.4 kb S1 genotypes. These results independently support the previous separation of the late-onset subgroup. Finally, the stronger associations at S rather than at the downstream Sl, Gm and D14S1 loci suggest that the genes predisposing to MG are located within the variable region of the Ig heavy chain loci.     

Use of interferon alpha in intratumoral chemotherapy for cystic craniopharyngioma

Objectives This study analyzed the intratumoral activity of interferon alpha (IFN-) in the treatment of cystic craniopharyngiomas.Patients and methods From January 2000 to January 2004, nine patients presenting with cystic craniopharyngiomas were treated with intratumoral injection of IFN- at the Pediatric Oncology Institute of the Federal University of São Paulo–Escola Paulista de Medicina. Age ranged from 1 year and 10 months to 18 years (mean 10 years). All intratumoral catheters were inserted by a subfrontal approach. Doses varied from 36 to 108 MU.Results There was complete disappearance of the lesion in seven cases. In two cases, partial reduction of tumor size was observed at follow-up. Follow-up varied from 1 year to 3 years and 6 months (mean 1 year 8 months).Conclusions IFN- proved to be an effective drug in the control of cystic craniopharyngiomas. Additional studies should be carried out to determine the optimal dose of IFN- in the treatment of cystic craniopharyngioma. In addition, other drugs possessing high efficacy and low neurotoxicity should be analyzed.     

Changes in the distribution of endothelial surface glycoconjugates associated with altered permeability of brain micro-blood vessels

Summary Lectin-binding sites located on the endothelial cell (EC) surfaces in unaltered, leaking and resorbing micro-blood vessels (MBVs) in cryo-injured cat brain were studied. Lectin or glycoprotein-gold complexes and brain samples embedded in hydrophilic resin Lowicryl K4M were used. The lectins tested recognize the following residues: -d-galactosyl (Ricinus communis agglutinin 120, RCA and peanut agglutinin, PNA), sialyl (Limax flavus agglutinin),N-acetyl-d-galactosaminyl (Helix pomatia agglutinin and soybean agglutinin, SBA), -d-glucosyl and -d-mannosyl (concanavalin A). The luminal front was labeled with SBA, and both fronts of the EC were labeled with PNA only after neuraminidase digestion. The most abundant and regularly distributed on both fronts of the EC were -d-galactosyl residues (RCA). These residues were also most affected in altered MBVs. The labeling of sialic acid residues was less pronounced on both sides of the EC. Following alteration of the function of the blood-brain barrier by cold-lesion injury, in leaking MBVs which represent increased luminal transport, we observed a conspicuous diminution of the labeling of the luminal surface of the EC with some lectins. On the other hand, in resorbing blood vessels located in the area of edema, where a presumably reverse (abluminal) transport occurs, major changes in the distribution of lectin-binding sites occurred on the abluminal front of the EC and in the basement membrane. The results reported here indicate that luminal and abluminal fronts of the EC change their properties in various functional conditions of MBVs, and that these changes can also be a reflection of functional polarity of brain endothelium.Supported in part by a grant from NINCDS no. 17271-05     

A new form of ovine GM1-gangliosidosis

neurological signs were observed in 3 lambs at approximately 1 month of age, in a flock of 1 ram and 29 ewes with 43 lambs. Deterioration occurred such that the lambs had either died or been killed by 4 months of age. Necropsies of two of these lambs revealed a diffuse encephalopathy in which the most prominent feature was ballooned neurons. Sections of frozen brain showed PAS-positive, oil red O-negative, and weak Sudan Black-positive material in the swollen neuronal cytoplasm. The ultrastructure of the neuronal inclusions showed characteristic whorled membranes, suggesting diagnosis of a gangliosidosis. The underlying enzymic defect was investigated by assaying 11 lysosomal enzymes in extracts of kidney from an affected lamb and from normal lambs. A deficiency (90%) of acidic -d-galactosidase was found in the affected lamb. All other activities, including N-acetylneuraminidase, were normal. A specific deficiency of lysosomal -d-galactosidase was demonstrated by separating the lysosomal and cytosolic -d-galactosidase by chromatography on concanavalin A-Sepharose. Diagnosis of G_M1-gangliosidosis, analogous to the severe infantile form of the human disease, was made on the basis of the pathology and enzymology. The -d-galactosidase activity in the white blood cells of the ram and several of the ewes was consistent with their being heterozygotes. This disorder is different from a previously described lipidosis in sheep, in which there was a combined deficiency of -d-galactosidase and -neuraminidase.     

Lectin histochemistry of gangliosidosis

Summary Lectin histochemical studies were performed on selected formalin-fixed, paraffin-embedded tissues of patients affected with the O variant of G_M2-gangliosidosis (i.e., Sandhoff's disease). The purpose was to identify specific sugar residues of undegraded stored substances in cytoplasm of affected cells. We studied neural tissues from 13 patients, visceral tissues from four patients, and placentae from three affected fetuses. Neurons in all 13 cases studied stained withConcanavalia ensiformis agglutinin (Con A) and withUlex europaeus agglutinin-I (UEA-I). Succinylated wheat germ agglutinin (S-WGA) stained affected visceral cells and astrocytes and macrophages in the central nervous system. These results demonstrate that -d-mannosyl and -l-fucosyl residues, which bind Con A and UEA-I, respectively, are present in affected neurons. Furthermore, they revealed the affected nonneuronal cells and astrocytes contain complex carbohydrates with nonreducing terminal -N-acetylglucosamine, which binds S-WGA.Supported by grant NS 2176 from the National Institute of Neurological and Communicative Disorders and Stroke     

Ultrastructural studies of concanavalin A receptors and 5′-nucleotidase localization in normal and injured mouse cerebral microvasculature

Summary Plant lectin concanavalin A conjugated with ferritin (Con A-F) injected i.v. was used for the detection of the specific monosaccharide residues (-d-mannosyl and -d-glucosyl) on the luminal surface of endothelial cells (ECs) in brain micro-blood vessels (MBVs). Both normal mice and animals with mechanically damaged blood-brain barrier (BBB) were used in this study. In addition, the activity of 5-nucleotidase (5N), the putative receptor for Con A, was studied cytochemically.Various methodologic experiments indicated that the reaction product formed on the luminal plasmalemma of ECs after incubation of samples in the cytochemical medium for the detection of 5N activity results from the action of unspecific phosphatase hydrolyzing both specific and nonspecific substrates. The abluminal side of the wall of MBVs seems to be a major location of 5N activity. Thus, no correlation between cytochemically demonstrable 5N activity and Con A receptor sites on the luminal surface of ECs was noted.After damage of the BBB, extensive internalization of the luminal plasmalemma forming the limiting membranes of pinocytotic vesicles, vacuoles, and endothelial channel-like structures was observed. This process was represented by a relatively rapid translocation of Con A receptors from luminal surface into the interior of the ECs and to the abluminal side of the vessel wall.Abbreviations AP Alkaline phosphatase - 5N 5-nucleotidase phate - AMP adenosine 5-monophosphate - CMP cytidine 5-monophosphate - GMP guanosine 5-monophosphate - UMP uridine 5-monophosphate - Con A concanavalin A - BBB blood-brain barrier - EC endothelial cell - HRP horseradish peroxidase - MBVs micro-blood vessels - NDPase nucleoside diphosphatase Supported in part by a grant from NINCDS No.17271-03     

Skeletal muscle pathology of mannosidosis in two siblings with spastic paraplegia

Summary Deficiency of -d-mannosidase was found in two siblings with muscle weakness and spastic paraplegia. A biopsy of the vastus lateralis muscle was studied by light and electron microscopy. Cryostat sections showed mild fiber size variation but no necrosis. Semithin Epon sections revealed many vacuoles in the muscle cells and fibroblasts. Electron microscopy showed that the vacuoles, presumably lysosomal, had a single limiting membrane and contained finely granular or granulo-reticular material, membranous structures, and electron-dense ovoids. The vacuoles were identical with those in lymphocytes and other cells of patients with mannosidosis. Disorganization of sarcomere alignment and widening of intermyofibrillar spaces were also observed. Deficiency of -d-mannosidase is considered to cause slowly progressing degeneration of muscle fibers.     

Prostaglandin F2α levels in human cerebrospinal fluid in normal and pathological conditions

Summary Prostaglandin F₂ concentrations in cerebrospinal fluid (CSF) from normal human subjects and patients with various pathological disorders of the central nervous system (CNS) were measured by radioimmunoassay. The mean PGF₂ level in 54 controls with no evidence of organic CNS disease was 67 pg/ml (range: 25–150 pg/ml). A significant increase of PGF₂ levels was demonstrated in most samples from patients with CNS diseases. Extremely high values were found in patients with stroke and subarachnoid hemorrhage when samples were collected shortly after the cerebral attack. With the regression of clinical symptoms and radiological findings a decrease of PGF₂ levels was demonstrated in this group of patients. In 32 patients with cerebral transient ischemic attacks a mean PGF₂ concentration of 170 pg/ml (range: 35–355 pg/ml) was found. Increased PGF₂ levels were found in patients with epilepsy when samples were collected within a few days after a convulsion. PGF₂ levels of four patients with slow progredient forms of multiple sclerosis without clinical symptoms at the time of sample collection were not different from normal controls while the mean PGF₂ level of all other patients with multiple sclerosis was 152 pg/ml (range: 55–325 pg/ml). Moreover, increased values could be demonstrated in patients with cerebral tumors and inflammatory processes.

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Zusammenfassung Mittels Radioimmunoassay wurden PGF₂-Konzentrationen im Liquor cerebrospinalis von normalen Personen und von Patienten mit verschiedenen Erkrankungen des ZNS gemessen. Der mittlere Prostaglandin-F₂-Spiegel von 54 Normalpersonen betrug 67 pg/ml (Bereich: 25–150 pg/ml). Bei den meisten Erkrankungen des ZNS unseres Patientengutes konnten deutliche Erhöhungen der PGF₂-Konzentration im Liquor cerebrospinalis festgestellt werden. Auffallend hohe Werte fanden wir bei Patienten mit ischämischen und hämorrhagischen Insulten als auch bei Subarachnoidalblutungen, wenn die Liquorabnahme innerhalb weniger Tage nach der Attacke erfolgte. Mit zunehmender Besserung des klinischen und röntgenologischen Befundes zeigte sich bei dieser Krankheitsgruppe eine rasche Normalisierung der PGF₂-Konzentration im Liquor. Bei 27 Patienten mit transitorisch-ischämischen zerebralen Attacken fanden wir einen mittleren PGF₂-Spiegel von 170 pg/ml (Bereich: 35–355 pg/ml). Bei Patienten mit Epilepsie zeigte sich ein deutlicher Anstieg der PGF₂-Konzentration in Zusammenhang mit Krampfanfällen mit Normalisierung der Werte nach längeren, anfallsfreien Phasen.Bei 4 Patienten mit einer milden Verlaufsform einer Multiplen Sklerose ohne besondere klinische Symptomatik zum Zeitpunkt der Liquorabnahme wurden normale PGF₂-Spiegel gefunden, während der mittlere Spiegel aller 10 Patienten mit Multipler Sklerose mit 152 pg/ml doch deutlich erhöht war. Hohe PGF₂-Konzentrationen fanden wir auch im Liquor von Patienten mit Tumoren des ZNS und Meningitis bzw. Meningoenzephalitis.

     

Time course changes of estrogen receptor α expression in the adult rat hippocampus after kainic acid-induced status epilepticus

Although estrogens possess neuroprotective and epileptogenic properties, the expression pattern of the estrogen receptor (ER) following status epilepticus (SE) remains unclear. We therefore examined the expression pattern of ER in the adult rat hippocampus after SE. SE was induced in rats by kainic acid (KA; 12 mg/kg, i.p.). ER expression was assessed by immunostaining and Western blotting at various times (24 h, and 7, 14, and 21 days) after SE onset. Immunohistochemistry disclosed ER expression in the CA1 and CA3 pyramidal cells of control rats, whereas, after SE, ER-immunoreactive neurons decreased in number due to neuronal death in the CA1 from days 7 to 21. On the other hand, ER-immunoreactive cells with astrocytic morphology were observed in the CA1 beginning on day 7 after SE. This immunoreactivity increased in proportion to the hypertrophy of astrocytes up to day 21. Western blotting revealed a significant decrease in ER expression on day 7 after SE in comparison with control level. However, ER expression on days 14 and 21 were similar when comparing KA-treated and control rats. These results indicate that reactive astrocytes are important sites of estrogen action in the hippocampal CA1 after SE.     

Experimentelle Untersuchungen über sympathische α- und β- Rezeptoren im Bereich der Cardia und des Sphincter Oddi

Zusammenfassung Das Adrenalin und Isopropylnoradrenalin wirken selektiv auf die sympathischen - bzw. -Rezeptoren und lösen unter jeweils typischen Bedingungen (Latenzzeit, Wirkungsstärke und Wirkungsdauer) den experimentellen Cardiospasmus des Kaninchens, der nach doppelseitiger Vagotomie auftritt. Das Adrenalin (-Rezeptor) führt zu einerErschlaffung der spastisch kontrahierten sphinctermuskulatur der Cardia. Das Isopropylnoradrenalin (-Rezeptor) löst einrhythmisches Spiel (Öffnung/Schluß) der Cardia aus, wie es sonst nur am intakten Versuchtstier beobachtet wird. ähnliche Verhältnisse liegen auch im Bereich des Sphincter Oddi des Hundes vor. Die Anregung des sympathischen -Rezeptors führt für eine bestimmte Zeit zu einerkontinuierlichen Erschlaffung des Sphincter Oddi. Die Aktivierung des -Rezeptors löst dagegen einrhythmisches Spiel des Oddi-Sphincters aus, wobei seine Schluß- und Öffnungsphasen alternieren. Dieser Effekt entspricht weitgehend der normalen Tätigkeit der Papille. Der sympathische -Rezeptor dürfte daher der eigentliche Motor der normalen Funktion in diesem Gebiet der Gallenwege sein. Das Follikelhormon und Progesteron blockieren nur die Wirkung der -wirksamen Sympathicomimetica und auch des Cholecystokinins auf den Sphincter Oddi. Der -Rezeptor wird dagegen von diesen beiden Hormonen nicht ausgeschaltet. Ein ähnlicher Effekt tritt auch bei schwangeren Tieren auf.

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Summary Adrenalin and Isopropylnoradrenalin operate selectively on the sympathetic -and -receptors respectively, and induce under typical conditions (latency-period, effectivity and duration of effect) the experimental cardiospasm of the rabbit that appears after bilateral vagotomy. Adrenalin (-receptor) induces aslackening of the spastically contracted sphincter muscle of the cardia. Isopropylnoradrenalin (-receptor) induces rhythmic play (opening, closure) of the cardia as is usually observed only in intact laboratory animals. Similar conditions are also present in the sphincter oddi area of the dog. Stimulation of the sympathetic -receptor brings about, for a certain period, apersisting slackened state of the sphincter oddi. Activation of the -receptor, on the other hand, gives rise to arhythmic play of the sphincter oddi in which the closure and opening phases alternate. This effect corresponds in large part to the normal activity of the papilla. The sympathetic -receptor might therefore be the real motor of normal function in this are of the gall ducts. FSH and Progesteron simply block the effect of the -effective sympathicomimetica and of the cholecystocinine on the sphincter oddi. The -receptor, on the other hand, is not blocked by these two hormones. A similar effect occurs also in pregnant animals.

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Résumé L'adrénaline et l'isopropylnoradrénaline agissent sélectivement sur les récepteurs sympathiques resp. et résolvent, dans des conditions chaque fois typiques (temps latent, force et durée d'efficacité), le cardiospasme expérimental du lapin intervenant après une vasotomie double: l'adrénaline (récepteur ) mène à unrelâchement de la musculature du sphincter contractée spasmodiquement du cardia. L'isopropylnoradrénaline (récepteur ) déclenche unjeu rythmique (ouverturefermeture) du cardia tel qu'on ne l'observe autrement que chez l'animal intact d'essai. Des conditions analogues se présentent aussi dans le domaine du sphincter Oddi du chien. L'excitation du récepteur sympathique mène pour un temps déterminé à unrelâchement continu du sphincter Oddi. L'activation du récepteur , par contre, déclenche unjeu rythmique du sphincter Oddi, avec alternance de ses phases de fermeture et d'ouverture. Cet effet correspond dans une large mesure à l'activité normale de la papille. le récepteur sympathique sera donc vraisemblablement le moteur proprement dit de la fonction normale dans ce domaine des canaux biliaires. L'hormone folliculaire et le progestérone bloquent seulement l'action des sympathicomimétiques à efficacité et aussi de la cholécystoquinine sur le sphincter Oddi. Par contre, le récepteur n'est pas éliminé par ces deux hormones. Un effet analogue intervient aussi chez les animaux enceints.

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Mit 6 Textabbildungen     

Occurrence of α-synuclein pathology in the cerebellum of Guamanian patients with parkinsonism-dementia complex

Amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC) is a progressive neurodegenerative disease affecting the indigenous Chamorro population of Guam. Neuropathologically, PDC is characterized by neuronal loss in the substantia nigra pars compacta with severe widespread neurofibrillary tangles (NFTs) similar to those observed in Alzheimers disease (AD), and is thus considered a tauopathy. Following reports of -synuclein pathology in PDC patients of Guam, PDC has also been neuropathologically classified as a synucleinopathy. Recently, the presence of -synuclein-positive bodies has been reported in the cerebellum of some patients with Parkinsons disease (PD), diffuse Lewy body disease (DLBD), or multiple system atrophy (MSA). Using immunohistochemical techniques, we investigated the deposition of -synuclein in the cerebellum of Guamanian PDC patients. Numerous -synuclein-immunoreactive spherical structures were found in the molecular layer of the cerebellum of 63.6% of PDC patients. These structures were only seen in patients showing -synuclein pathology in the amygdala. The average density of -synuclein-immunoreactive structures in the cerebellum of Guamanian PDC patients was almost an order of magnitude higher than in non-Guamanian PD patients, and this -synuclein pathology was much more pronounced in the hemisphere than in the vermis. In addition, double immunohistochemistry revealed that cerebellar -synuclein is co-localized with the neuronal marker calbindin and with glial-fibrillary acidic protein, suggesting the involvement of Purkinje cells and Bergmann glia. These findings demonstrate that the -synuclein pathology in PDC of Guam affects not only the amygdala, but also the cerebellum, where it appears to involve both Purkinje cells and specialized astrocytes.     

Antipsychotic treatment withα-methyltyrosine in combination with thioridazine: Prolactin response and interaction with dopaminergic precursor pools

Summary The antipsychotic effect of-methyltyrosine (-MT) in combination with thioridazine was investigated by means of rating scales for social behaviour and mental symptoms The clinical effect was also evaluated in relation to the serum concentrations of-MT and thioridazine and to the increase in prolactin secretion in response to the interaction with hypothalamic dopaminergic mechanisms. The interactions between the serum levels of-MT and those of the transmitter precursors phenylalanine and tyrosine were analysed. The results confirmed the ability of-MT (2g/day) to potentiate the antipsychotic effect of thioridazine, whereby the dose of neuroleptic drug required to control psychotic symptoms may be markedly reduced. None of the four patients who completed the trial showed side effects that could be ascribed to-MT. The antipsychotic effect of thioridazine, alone or in combination with-MT, correlated well with the prolactin response in the individual patient. No important interference with serum phenylalanine or tyrosine levels was noted during treatment with-MT.