Liquorkomplement und Multiple Sklerose

Zusammenfassung 1. In 239 Liquores, darunter 47 MS-Fälle und 91 normale Kontrollen, wurden Komplement und Komplementfaktoren (C₁, C₂, C₃ und C₄) bestimmt.2. Im normalen Liquor ist in der Regel keine Gesamtkomplementaktivität vorhanden. Dagegen ist die C₁- wie C₄-Aktivität praktisch immer und C₂-sowie C₃-Aktivität in über der Hälfte der Fälle zu finden. Das Komplementmuster im Liquor ist daher im Gegensatz zum Serum unvollständig.3. Bei erhöhtem Eiweiß zeigt der Liquor dagegen häufig Gesamtkomplementaktivität. Je höher das Liquoreiweiß ist, um so höher ist der Gehalt an C₂, C₃ und Gesamtkomplement. Diese Beziehungen zwischen Gesamteiweiß und Komplementaktivität gelten für normalen wie pathologischen Liquor einschließlich der MS-Fälle.4. Im MS-Liquor sind C₂, C₃ und Gesamtkomplement seltener zu finden als bei den Kontrollen. Bei den MS-Patienten ist C₂ und C₃ im akuten Schub herabgesetzt. C₃ nimmt im Verlauf der Erkrankung wahrscheinlich ab.5. Mit Antikomplementserum wurde _1C-Globulin, ein Teilfaktor von C₃, im Liquor von 55 MS-Patienten und 42 Kontrollen bestimmt. Es besteht kein Unterschied zwischen MS und Kontrolliquor. Auch bei akut entzündlicher MS ist _1C nicht vermindert.6. In der Diskussion wird auf widersprechende eigene Befunde über _1C-Inaktivierung im Serum während der akut entzündlichen MS-Phase hingewiesen.

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Summary 1. Complement and complement factors (C₁, C₂, C₃ and C₄) were determined in 239 specimes of cerebrospinal fluid (CSF) including 47 cases of Multiple Sclerosis (MS) and 91 normal controls.2. In general, total complement activity is absent in normal specimens while that of C₁ and C₄ can be found practically always and that of C₂ and C₃ in more than half of the cases. Therefore, the pattern of complements in the CSF is incomplete as opposed to that of serum.3. In contrast, samples with increased protein content frequently yield total complement activity. The higher the protein content of CSF the higher the content of C₂, C₃ and total complement. This relationship between amount of total protein and complement activity applies both to normal and pathological CSF specimens including those from MS.4. In cerebrospinal fluid from patients with MS, C₂, C₃ and total complement are found less frequently than in that from controls. C₂ and C₃ are diminished in patients with an acute exacerbation of MS. C₃ decreases probably in the course of the disease.5. _1C-globulin, a component of C₃, was determined with anticomplement sera in specimens from 55 patients with MS and from 42 controls. There is no difference between CSF of MS and controls. Even in acutely inflammatory cases of MS, _1C is not diminished.6. Discussing his results the author points out discrepancies concerning the nactivation of _1C in serum during acutely inflammatory episodes of MS.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

In situ hybridization with digoxigenin-labeled probes: sensitive and reliable detection method applied to myelinating rat brain

Summary A method for in situ hybridization of digoxigenin-labeled cDNA and cRNA probes to myelin protein mRNA is described. This technique has dual advantages of high structural resolution and high sensitivity and avoids problems associated with handling of radioactive materials. Furthermore, it can be readily combined in double labeling with immunocytochemical protein detection. We have used this technique to detect and locate mRNA for myelin basic protein (MBP), proteolipid protein (PLP), 2,3-cyclic nucleotide 3-phosphodiesterase (CNPase) and myelin-associated glycoprotein (MAG) in oligodendrocytes of 7-day-old and adult rat brains. PLP and MAG mRNA were restricted to the perinuclear cytoplasm, whereas MBP and CNPase mRNA was additionally present in peripheral oligodendrocyte processes.Supported by the Science Research Fund, Austria, P 7740M     

Dysbalance of neuronal second messenger function in the aetiology of affective disorders: A pathophysiological concept hypothesising defects beyond first messenger receptors

Summary It is suggested that affective disorders arise from the dysbalance of the two major intraneuronal signal amplification systems, the adenylate cyclase and the phospholipase C system, with depression resulting from underfunction of cyclic adenosine 3,5-monophosphate-mediated effector cell responses associated with an absolute or relative dominance of the inositoltriphosphate/ diacylglycerol-mediated responses and mania resulting from the converse. The usefulness of this hypothesis is discussed with respect to (a) the mechanism of action of current therapeutic agents and (b) the development of novel therapeutic approaches.     

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     

Human glial fibrillary acidic protein (GFAP): molecular cloning of the complete cDNA sequence and chromosomal localization (chromosome 17) of the GFAP gene

Summary We isolated three glial fibrillary acidic protein (GFAP) cDNA clones from a glioma cell line, U-251 MG. One clone isolated from a U-251 MG cDNA library was long, but lacked both ends. Using poly(A)⁺ RNA and primers synthesized according to the sequence of this clone, we used the polymerase chain reaction-assisted rapid amplification of cDNA ends (PCR-RACE) method, which is a strategy to isolate cDNA ends, and obtained cDNA clones for the 5 and 3 ends. From the sequences of these overlapping clones, the complete nucleotide sequence of human GFAP cDNA was established. The start (ATG) and the stop (TGA) signals were seen at nucleotide positions 15 and 1311, respectively, and divided the entire sequence of 3027 bp into 14 bp of 5 non-coding, 1296 bp of coding and 1717 bp of 3 non-coding regions. Using cDNA probes made from both the coding and the 3 non-coding regions, Northern blot hybridization was performed with two different stringencies on RNAs from human and rodent brains and human GFAP-positive and-negative cells. It was shown that the 3 non-coding region probe was more specific for human GFAP than the coding region probe which was specific only under higher stringency conditions. This was also suggested by homology analysis of the sequence with those of various intermediate filament proteins. Based on these findings, we performed spot blot hybridization of sorted human chromosomes and Southern blot hybridization of PCR-amplified DNAs of a panel of hamster-human somatic cell hybrids and localized the human GFAP gene to chromosome 17.     

S-100 protein and 2′,3′-cyclic nucleotide 3′-phosphohydrolase in human brain tumors

Summary Biopsy specimens from 23 human brain tumors have been analyzed for the nervous system specific protein S-100 and the membrane-associated enzyme 2,3-cyclic nucleotide 3-phosphohydrolase (CpNase). Biopsy specimens from an additional seven brain tumors were tested for either S-100 or CpNase alone.All astrocytomas and glioblastomas tested were found to contain S-100 and CpNase although there does not appear to be a strong correlation between the levels of these two markers in the 14 such tumors assayed for both. S-100 levels varied over a 19-fold range while CpNase varied over a 835-fold range. Postoperative survival in the astrocytoma and glioblastoma patients showed only a weak correlation with either tumor CpNase or S-100 levels.Two acoustic neurinomas, two oligodendrogliomas, one mixed glioma, and one choroid plexus papilloma were also assayed and found to have detectable levels of both S-100 and CpNase with the acoustic neurinomas and the mixed glioma having relatively high levels of each marker. All six meningiomas tested had low levels of CpNase. S-100 assays in three benign meningiomas were negative, while low levels of this protein were found in the one malignant meningioma tested.Tissue cultures were grown out from biopsy specimens of additional human brain tumors and tested at confluency for S-100. Of 15 astrocytoma and glioblastoma cultures tested, three had easily detectable amounts of S-100, two appeared to contain trace levels and ten were negative. The two acoustic neurinoma cultures tested were positive for S-100 while all three oligodendroglioma cultures were negative.     

Heterologous supersensitization between serotonin2 and alpha2-adrenergic receptor-mediated intracellular calcium mobilization in human platelets

Summary Recent reports suggest that serotonin (5-HT)₂ receptor-mediated second messenger systems are enhanced in platelets of affective disorders. To make the mechanism of the enhanced response clear, we investigated 5-HT₂ and alpha ()₂-adrenergic receptor-induced intracellular calcium (Ca²⁺) mobilization in platelets of healthy volunteers, using fura-2. 5-HT₂ and ₂-adrenergic receptor-mediated Ca²⁺ mobilization was enhanced by prior exposure to the other type of agonist, so called heterologous supersensitization. The supersensitization was due to the enhancement of maximal response without change in agonist affinity. Chelating extracellular Ca²⁺ did not diminish the supersensitization. This enhancement of Ca²⁺ mobilization was not inhibited by H-7, an inhibitor of protein kinase C. However, this supersensitization was inhibited by pretreatment with sodium fluoride which directly activates guanine nucleotide binding regulatory proteins (G proteins). These results suggest that the supersensitization was caused from intracellular Ca²⁺ storage sites through a G protein-coupled pathway.Abbreviations fura-2/AM 1-(2-(5-carboxyoxazol-2-yl)-6-aminobenzofuran-5-oxy)-2-(2-amino-5-methylphenoxy)-ethane-N,N,N, N-tetraacetic acid, pentaacetoxymethyl ester - H-7 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride - EGTA ethylenedioxybis(ethylamine)-N,N,N,N-tetraacetic acid - HEPES 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid - NaF sodium fluoride - Fmax maximal fluorescence intensity - Fmin minimal fluorescence intensity     

Isolation of a cDNA encoding the human brain serotonin transporter

Summary A cDNA encoding a serotonin transporter (5-HTT) in the human dorsal raphe nucleus was isolated and sequenced using cross-species amplification of human 5-HTT partial cDNA by the polymerase chain reaction (PCR) and the RACE-PCR procedure, designed for rapid amplification of 3 and 5 cDNA ends. The cDNA contains an open reading frame encoding a hydrophobic polypeptide of 630 amino acids with a calculated molecular weight of 70 kDa. The human 5-HTT is 92% homologous to the rat protein but contains an additional consensus phosphorylation site for cAMP-dependent protein kinase recognition located in the cytoplasmic N-terminal region, while a potential protein kinase C phosphorylation site identified in the rat homolog is not conserved in the human 5-HTT. Hydropathicity analysis revealed twelve membrane spanning segments, a topology proposed for other cloned sodium-dependent transporters.     

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.     

“Sporadic” prealbumin-related amyloid polyneuropathy: report of two cases

Summary Two sporadic cases of amyloid polyneuropathy are reported. There was no family history or plasma cell dyscrasia. Both showed sensorimotor and autonomic polyneuropathy with onset in the seventh decade. Amyloid deposits in both cases reacted with anti-human prealbumin sera but not with antisera to human AA and anti-human immunoglobulin light-chain amyloids, including A and A. One patient had the abnormal serum prealbumin and abnormal DNA sequence found in type I familial amyloid polyneuropathy (FAP) (Japanese type). Investigations in sporadic amyloid polyneuropathy should include immunohistochemistry, using antisera to the different amyloid proteins, and the radioimmunoassay and recombinant DNA techniques for diagnosis of FAP.     

The effect of oxidative stress on amyloid precursor protein processing in cells engaged in β-amyloidosis is related to apolipoprotein E genotype

The reduced antioxidative defense in allele 4 carriers is suggested to contribute to -amyloidosis in Alzheimers disease and Downs syndrome. We studied the effect of oxidative stress on accumulation of amyloid- peptide (A) in vascular smooth muscle cells (SMCs) that are engaged in production of amyloid- in vivo. Previously, we found that oxidative stress caused by ferrous ions induced accumulation of A-apolipoprotein E deposits in lysosomes and was associated with a greater oxidative protein damage in 4 carriers. Here, we demonstrate that ferrous ions induce formation of A deposits also in vascular tunica media in organotypic cultures of whole brain vessels, suggesting the role of oxidative stress in development of vascular -amyloidosis. Cellular accumulation of A in SMCs treated with ferrous ions was associated with a greater accumulation of C-terminal amyloid precursor protein (APP) fragments in 4/4 than in 3/3 myocytes and reduced the amount of soluble APP in 3/3, but not 4/4, cultures. Antioxidant vitamin E prevented these effects, and, when applied alone, diminished the amount of APP C-terminal fragments and increased the amount of secreted APP in 3/3, but not 4/4, cells. C-terminal APP-immunoreactive material was accumulated in lysosomes partly with A- and N-terminal APP immunoreactivities. These results suggest that the increased accumulation of APP and its fragments in lysosomes may yield additional amounts of cellular A, particularly in 4 carriers. We hypothesize that the altered processing of APP in SMCs locally exposed to oxidative stress facilitates cellular deposition of A and contribute to the increased risk of development of -amyloidosis in 4/4 carriers.     

Refraktärperioden und frequente Impulsfortleitung im gemischten N. ulnaris des Menschen bei Polyneuropathien

Zusammenfassung Bei 30 Patienten mit Neuropathien unterschiedlichen Schweregrades (subklinisch, leicht, mittelschwer und schwer) wurden am N. ulnaris neben den üblichen neurophysiologischen Parametern [distale Latenz, maximale motorische und gemischte Nervenleitgeschwindigkeit (Nlg.)] die Refraktärperioden (Rp.) (absolute Rp. und relative Rp.-Amplitude und -Latenz) und die unteren Grenzfrequenzen (u. F.) (u. F.-Amplitude und -Latenz) bestimmt.Beim Vergleich mit einem Normalkollektiv (n=31, s. Lowitzsch u. Hopf, (1972a)) war die Nlg. nur in 37% der Fälle pathologisch verlangsamt, während die relative Rp.-Latenz in ca. 80% und die u. F.-Latenz in ca. 60% pathologisch verändert waren.In zwei Stichproben (13 Normalfälle und 13 Polyneuropathien) mit einer normalen gemischten Nlg. von 51,0–63,5 m/sec unterschieden sich die Mittelwerte für die distale Latenz sowie die motorische und gemischte Nlg. statistisch nur auf dem 1%-Niveau, für die relative Rp.-Latenz und die u. F.-Latenz hingegen auf dem 0,5-Niveau.Die Bestimmung der Refraktärperioden, insbesondere der rel. Rp. L., sowie der unteren Grenzfrequenz (u. F. L.), stellt eine im Vergleich mit den üblichen neurophysiologischen Verfahren (Nlg.-Bestimmung) wesentlich empfindlichere Untersuchungsmethode zur Erfassung auch geringer (subklinischer) Funktionsstörungen des peripheren Nervensystems dar.Die unterschiedliche Beeinflussung der Refraktärperioden und der Grenzfrequenzen durch die Art des zugrundeliegenden pathologischen Prozesses (axonale Degeneration — segmentale Demyelinisierung — Mischtyp) wird an Hand der in 9 Fällen nervenbioptisch (N. suralis) gewonnenen Befunde diskutiert.

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Refractory periods and frequent impulse conduction in mixed N. ulnaris of man in polyneuropathies

Summary Some electrophysiological parameters were studied in the ulnar nerve of 30 patients suffering from neuropathy of various origin and severity.Absolute and relative refractory periods and lower limiting frequencies were measured and compared to the usual parameters (distal motor latency, conduction velocity of motor fibres, and the mixed nerve action potential).The conduction velocity was indicative of the diseased function in 37% whereas the relative refractory period (latency) was abnormal in nearly 80% and the lower limiting frequency (latency) in about 60%.Two samples taken at random, each of them consisting of 13 patients with normal conduction velocities between 51.0 and 63.5 m/sec showed differences only at the 1% level (p<0.01) as far as the mean values of the distal latency and the maximum conduction velocity were concerned. The difference between the mean values of the relative refractory period (latency) and of the lower limiting frequency (latency), however, was highly significant (p<0.0005). Thus, in our experience, the relative refractory period (latency) and the lower limiting frequency (latency) are more sensitive indicators of mild functional disturbances of peripheral nerves than the maximum conduction velocity.

Die Untersuchungen wurden in dankenswerter Weise von der Deutschen Forschungsgemeinschaft unterstützt.     

Dystrophin deficiency in a case of congenital myopathy

Summary We studied a 5-year-old boy who had the floppy infant syndrome and a dystrophic pattern on muscle biopsy. According to the clinical presentation and the histopathological findings the diagnosis of congenital muscular dystrophy with associated intellectual retardation was made. Immunohistochemical and immunoblot studies using anti-dystrophin antibodies showed complete absence of the protein in the patient's muscle. DNA analysis using cDNA probes showed a deletion at the 5 end of the dystrophin gene. Our observations on this patient suggest a new phenotypical variant of Duchenne muscular dystrophy.     

Attitudes toward mental health professionals in a hospital-based community mental health center

This study examined the attitudes of several diverse subject groups in a large medical center toward various mental health professionals. The groups consisted of: 1) general hospital staff; 2) professional mental health workers; and 3) psychiatric in-patients. Subjects evaluated a selection of 11 professional health related role titles (clinical psychologist, physician, psychiatrist, etc.) and the categories me and mental patient by marking a series of 19 seven-step rating scales, each composed of bipolar anchoring adjectives. Additionally, a familiarity rating for each of the role titles was obtained. An understanding and a value cluster were derived from the 19 adjectives along with an overall favorability-unfavorability score for each role title. It was expected that subjects would value mental health professional roles more strongly than they would indicate an understanding of these same roles. Secondly, it was expected that the hospital setting itself, the subject's role within that setting, and the degree of familiarity with the role being rated would have a significant impact on the subject's attitude. Results generally supported the above expectations. Overall ratings of the professional groups were consistently high, with less difference between the health designations (physician, nurse) and the psych designations than has been previously reported in the literature.     

Comparison of the active standing test and head-up tilt test for diagnosis of syncope in childhood and adolescence

Abstract We examined 51 children and adolescents with orthostatic symptoms using two orthostatic tests, the active standing test (the AS test) and head-up tilt test (HUT), and compared circulatory responses, autonomic function in addition to the induction rate of syncope during short-time orthostasis. Syncope was induced in eight patients with both tests, in only six patients with the AS test and in only one patient with HUT. The induction rate was significantly higher with the AS test (p<0.0001). In addition, the AS test is common and daily postural motion and does not require a tilt table. We calculated percent changes in systolic blood pressure at the initial drop (ID-SBP), in systolic blood pressure (SBP), in diastolic blood pressure (DBP), in heart rate (HR), component coefficient variation LF/HF (LF/HF) from supine to upright. HR were significantly larger in fainters than in non-fainters with both tests, although there was no difference in SBP and in DBP. In six fainters only with the AS test, HR was significantly larger with the AS test than with HUT. With the AS test ID-SBP were correlative with LF/HF, and LF/HF were correlative with HR, whereas these relations were not clear in HUT. These results indicated the AS test caused cardiac sympathetic activation associated with an initial pressure drop, and was more prone to induce syncope with a greater HR increase in some patients. We conclude the AS test is as potential as HUT as a diagnostic test for syncope.     

Characterization of an established human malignant glioma cell line: LN-18

Summary A human malignant glioma cell line, LN-18, has been established in monolayer culture and subcultured for more than 115 passages. LN-18 cells grow in vitro as bipolar or stellate cells with pleomorphic nuclei, have a doubling time of about 72 h and a plating efficiency of 3%. The glial nature of these cells has been assessed by ultrastructural examination. The synthesis of glial fibrillary acidic and S-100 proteins could not be demonstrated, although the initial biopsy tissue and the early cultures were positive for the former. The presence of Ia-like antigens on the surface of these cells was demonstrated using allo and xeno antisera. LN-18 cells were also shown to synthesize large quantities of fibronectin. The injection of LN-18 cells into nude mice induced the formation of solid tumor masses that could be retransplanted every 3 weeks and showed a morphology comparable to that of the initial biopsy. Karyotype analysis revealed the presence of three marker chromosomes, constantly present before and after hetero-transplantation.Abbreviations GFA glial acidic fibrillary protein This work was supported by grants from the Swiss League Against Cancer and the Swiss National Foundation for Scientific Research CNP: 23-cyclic nucleotide 3-phosphodiesterase     

Human acoustic neurinomas: Nervous system specific biochemical parameters

Summary A series of 24 human acoustic neurinomas from 24 patients has been assayed for several biochemical parameters characteristic of the nervous system. S 100 protein, 2, 3-cyclic nucleotide 3-phosphohydrolase activity, and the myelin lipids galactosylceramide and sulfogalactosylceramide (sulfatide). Myelin basic protein was not detected. These findings further support the neuroectodermal origin of the human acoustic neurinoma, and provide additional biochemical markers for further study.     

Life events and syndromes of depression in the general population

Summary Brown and Harris (1978) contend that life events have causal significance for both psychotic and neurotic depression. This contradicts the psychiatric tradition. Neurotic depression has been regarded as a consequence of life-stress, while psychotic depression has been regarded as a consequence of processes intrinsic to the organism. Empirical evidence is presented to support the view that life events have a differential effect, within the general population. It is argued that Brown and Harris's (1978) conclusion follows from an inappropriate approach to classification. It is argued further that their data lend support to the traditional view. It is noted that their approach may inhibit the development of explanatory models linking life-stress, vulnerability factors and depression.     

Effect of dantrolene on KCl- or NMDA-induced intracellular Ca2+ changes and spontaneous Ca2+ oscillation in cultured rat frontal cortical neurons

Summary Dantrolene has been known to affect intracellular Ca²⁺ concentration ([Ca²⁺]_i) by inhibiting Ca²⁺ release from intracellular stores in cultured neurons. We were interested in examining this property of dantrolene in influencing the [Ca²⁺]_i affected by the NMDA receptor ligands, KCl, L-type Ca²⁺ channel blocker nifedipine, and two other intracellular Ca²⁺-mobilizing agents caffeine and bradykinin. Effect of dantrolene on the spontaneous oscillation of [Ca²⁺]_i was also examined. Dantrolene in M concentrations dose-dependently inhibited the increase in [Ca²⁺]_i elicited by NMDA and KCl. AP-5, MK-801 (NMDA antagonists), and nifedipine respectively reduced the NMDA and KCl-induced increase in [Ca²⁺]_i. Dantrolene, added to the buffer solution together with the antagonists or nifedipine, caused a further reduction in [Ca²⁺]_i to a degree similar to that seen with dantrolene alone inhibiting the increase in [Ca₂₊]_i caused by NMDA or KCl. At 30 M, dantrolene partially inhibited caffeine-induced increase in [Ca²⁺]_i whereas it has no effect on the bradykinin-induced change in [Ca²⁺]_i. The spontaneous oscillation of [Ca²⁺]_i in frontal cortical neurons was reduced both in amplitude and in base line concentration in the presence of 10 M dantrolene. Our results indicate that dantrolene's mobilizing effects on intracellular Ca²⁺ stores operate independently from the influxed Ca²⁺ and that a component of the apparent increase in [Ca²⁺]_i elicited by NMDA or KCl represents a dantrolene-sensitive Ca₂₊ release from intracellular stores. Results also suggest that dantrolene does not affect the IP₃-gated release of intracellular Ca²⁺ and that the spontaneous Ca²⁺ oscillation is, at least partially, under the control of Ca²⁺ mobilization from internal stores.Abbreviations AP-5 (±)-2-amino-5-phosphonopentanoic acid - AMPA amino-3-hydroxy-5-methyl-isoxazole-4-propionate - BSS balanced salt solution - CNS central nervous system - CICR Ca²⁺-induced Ca²⁺ release - DCKA 5,7-dichlorokynurenate - DNasel deoxyribonuclease I - DMEM Dulbecco's Modified Eagle's Medium - EGTA ethylene glycol-bis(-aminoethyl ether)N,N,N,N,-tetraacetic acid - FCS fetal calf serum - fura-2-AM 1-(2-(5-carboxyoxazol-2-yl)-6-aminobenzofuran-5-oxy-2-ethane-N,N,N,N-te-traacetic acid, pentaacetoxymethyl ester - HEPES N-[2-hydroxyethyl] piperazine-N-[2-ethanesulfonic acid] - [Ca ²⁺] _i intracellular free Ca²⁺ concentration - LTP long-term potantiation - MK-801 (5R, 10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,b]-cyclohepten-5,10-imine hydrogen maleate - NMDA N-methyl-D-aspartate     

Reliability of death certificates in the study of stroke mortality. A retrospective study in a Sicilian municipality

The subjects who died in the Sicilian municipality of Riposto between 1985 and 1992, and whose death certificates reported diagnoses of cerebrovascular disease, were re-evaluated with the aim of verifying the reliability of the certificates themselves. The relatives of the deceased were interviewed to confirm or exclude stroke, and about 35% of the cases proved to be false positives. Among the causes reported on the death certificates, stroke, cerebral hemorrhage and cerebral thrombosis presented the smallest number of false positives. Our results show that the sensitivity and specificity of the death certificates was poor, and there would also seem to be a large number of false negatives. However, the official mortality rates for cerebrovascular disease are probably not very far from the truth.

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Sommario Abbiamo rivalutato i soggetti deceduti nel comune siciliano di Riposto tra il 1985 e il 1992 il cui certificato di morte rioportava diagnosi di malattia cerebrovascolare, allo scopo di valutare l'attendibilità dei certificati di morte. Abbiamo intervistato i parenti dei deceduti per confermare o escludere l'ictus cerebrale e circa il 35% dei casi sono risultati falsi positivi. Tra le cause riportate sul certificato di morte, ictus, emorragia cerebrale e trombosi cerebrale hanno presentato il minor numero di falsi positivi. Dai nostri risultati emerge una bassa sensibilità e specificità dei certificati di morte, infatti anche i falsi negativi sembrerebbero numerosi. I tassi ufficiali di mortalità per vasculopatia cerebrale tuttavia non sono probabilmente molto lontani dalla realtà.