Low avidity of human serum antibodies for Borna disease virus antigens questions their diagnostic value

Borna disease virus (BDV) can induce neurological disease in animals. Since viral nucleic acid, infectious particles and antibodies recognizing BDV antigens were found at higher frequencies in psychiatric patients than in healthy controls, BDV is suspected to cause psychiatric disorders in humans. However, the human origin of these viruses has recently been questioned. To diagnose BDV infections, sera are usually analyzed for antiviral antibodies by indirect immunofluorescence (IFA) on virus-infected cells. This study reveals that the reactive antibodies in human sera mainly recognized the BDV phosphoprotein, whereas animal sera preferentially detected the viral nucleoprotein. Immunoglobulin (Ig) G in sera of experimentally or naturally infected animals bound to the viral antigen with high avidity, ie resisting 3 M urea, whereas reactive IgG in human sera did not. Longitudinal studies showed that reactive human antibodies persisted for many years without gaining high avidity for BDV antigens, indicating that they were probably not induced by BDV but rather by infection with an antigenically related microorganism of unknown identity or by exposure to other related immunogens.

Marked differences in unilateral isolated retinoblastomas from young and older children studied by comparative genomic hybridization

Although it is established that the loss of function of both alleles of the RB1 gene is a prerequisite for the development of retinoblastoma, little is known about the genetic events that are required for tumor progression. We used comparative genomic hybridization (CGH) to search for DNA copy number changes in isolated unilateral retinoblastomas. From a series of 66 patients with retinoblastomas with somatic mutations in both RB1 alleles, tumor samples from 13 children with the youngest (2.0-9.8 months) and 13 with the oldest (36.2-84.1 months) age at operation were studied. Loss at 13q14, the location of RB1, was demonstrated in two tumors only. Recurring chromosome imbalances included gains at 6p (11/26), 1q (10/26), 2p (4/26), and 17q (4/26), gains of the entire chromosome 19 (3/26), and losses at 16q (9/26). A commonly gained region at 1q32 was identified. Increased dosage of GAC1, a candidate oncogene located in 1q32, was found in two of four tumors by Southern blot analysis. Comparison of the CGH findings revealed that retinoblastomas from children with an older age at operation showed significantly more frequent (13/13 cases vs 4/13 cases; P = 0.0005) and more complex genetic abnormalities (median, 5 changes/abnormal tumor vs median, 1.5 changes/abnormal tumor; P = 0.003) than retinoblastomas from children with a young age at operation. Gains at 1q, 2p, 17q, of the entire chromosome 19 and losses of 16q were restricted to the older age group. Our results suggest that the progression of retinoblastomas from older patients follows mutational pathways different from those of younger patients.

Borna disease in horses

Borna disease is a sporadically occurring, progressive viral polioencephalomyelitis that primarily affects horses and sheep. The etiological agent, Borna disease virus (BDV), is an enveloped, single-stranded RNA virus that has been classified in the new virus family Bornaviridae within the order Mononegavirales. Serological evidence of BDV infection has been found in an increasing number of countries throughout the world. After an incubation period lasting a few weeks to several months, BDV infection can cause locomotor and sensory dysfunction followed by paralysis and death. Borna disease is the result of a virus-induced immunopathological reaction. BDV-specific antibodies and viral RNA have been found in humans with various psychiatric disorders.

Borna disease virus and schizophrenia in Surinamese immigrants to the Netherlands

Borna disease virus (BDV) has been suggested to play a role in the etiology of schizophrenia. We tested the hypothesis that markers of BDV infection are more frequent in Surinamese immigrants to the Netherlands, diagnosed with schizophrenia, than in Dutch-born healthy subjects. For reasons that are poorly understood there is an increased incidence of schizophrenia in this immigrant group. Blood was obtained from 29 male schizophrenic patients (DSM-IV criteria) and from 26 healthy males. For detection of anti-BDV antibodies an indirect immunofluorescence assay (IFA) was performed. A nested, reverse-transcriptase-PCR, using primers specific for the p24 and p40 BDV genes, was used to determine BDV-RNA in peripheral blood mononuclear cells. Contrary to our expectations, the frequencies of BDV markers in the group of healthy subjects, as determined by IFA and both PCRs, exceeded that in the group of patients. The results do not support an association between markers of BDV infection in blood and schizophrenia. It is unlikely that the high incidence of schizophrenia in Surinamese immigrants is caused by BDV, but the small number of subjects examined do not warrant definitive conclusions.

Changes in plasma elastase during pregnancy and sub partu

Elastase is produced and released by polymorphonuclear leukocytes (PNMs) during inflammatory processes. Thus, elastase is assumed to be a sensitive marker of infections similar to the well-established C-reactive protein (CRP). It is deactivated predominantly in tissues by alpha1-proteinase inhibitor which forms stable complexes with the elastase molecule (EAPI) that can be detected for several hours. Premature rupture of membranes is often correlated with an early increase in elastase, occurring earlier than the increase in leukocyte count or CRP. Elastase might be a sensitive marker of beginning amnion infection syndrome after premature rupture of membranes. For the present study, plasma EAPI levels of 335 healthy pregnant women as well as 47 healthy nonpregnant pre- and postmenopausal women were analyzed. No significant differences were found in the latter group or in pregnant women until the beginning of labor. Women at the beginning of labor but without rupture of membranes showed a significant increase in plasma EAPI from 97.7 to 338.3 ng/ml (p < 0.001). With opening of the os uteri to more than 2 cm, elastase concentrations decreased to values comparable to those before the beginning of labor (p < 0.001). The use of elastase as a marker for a rupture of membranes or beginning amnion infection syndrome as suggested by a number of studies might need some restriction. As a consequence, serial monitoring of plasma elastase to detect a persisting increase might give more reliable results. The increase in plasma elastase during beginning of labor may be explained by the role of PMNs in the physiology of delivery. However, serial monitoring to detect a persisting increase in plasma EAPI may be more helpful.

Distribution of Borna disease virus in the brain of rats infected with an obesity-inducing virus strain

Experimental infection of Lewis rats with Borna disease virus (BDV), a nonsegmented, single-stranded RNA virus, usually causes an immune-mediated biphasic neurobehavioral disorder. Such animals develop a persistent infection of the CNS with viral antigen expression in all brain regions and a disseminated nonpurulent meningoencephalitis. Interestingly, intracerebral infection of Lewis rats with a BDV-variant (BDV-ob) causes a rapid increase of body weight with the development of an obesity syndrome without obvious neurological signs. The obese phenotype is correlated with a characteristic distribution of inflammatory lesions and BDV-antigen in the rat brain. Infiltration with mononuclear immune cells and viral antigen expression are restricted to the septum, hippocampus, amygdala and ventromedian tuberal hypothalamus. Therefore, infection with the obesity-inducing BDV-ob results most likely in neuroendocrine dysregulations leading to the development of an obesity syndrome. This might be due to the restriction of viral antigen expression and inflammatory lesions to brain areas which are involved in the regulation of body weight and food intake. The BDV-induced obesity syndrome represents a model for the study of immune-mediated neuroendocrine disorders caused by viral infections of the CNS.

Pulsatile vs. continuous parenteral tocolysis: comparison of side effects

Bolus tocolysis has been developed to reduce the dose of fenoterol compared to continuous tocolysis. Whereas the high efficacy of pulsatile application of fenoterol has been shown, the proof of reduced side effects is still lacking. A total of 59 patients with preterm labor were divided in three groups: (1) continuous tocolysis and oral application of magnesium (n=19), (2) continuous tocolysis and parenteral application of magnesium (n=20), (3) pulsatile tocolysis (bolus tocolysis) and oral application of magnesium (n=20). Heart rate, systolic and diastolic blood pressure, serum K+ and serum Mg++ were quantified before tocolysis and after 2, 8 and 24 h. Beta-blockers and water balance were recorded over 24 h. Subjective side effects were quantified using a questionnaire with scales graduated covering palpitations, tremor, diaphoresis, thirst, precardialgia and nausea/vomiting. The analysis of the data revealed significantly fewer side effects concerning heart rate, plasma K+ level and the subjective side effects among patients treated with bolus tocolysis than among those treated with continuous tocolysis. Between the latter two groups, no significant difference was found. Concerning blood pressure and need for beta-blockers, no significant differences were found between the three groups. The results of the present study show that especially the side effects subjectively found to be disagreeable by the patients are reduced by pulsatile tocolysis, whereas other side effects show only slight differences between the study groups.

Fenoterol increases erythropoietin concentrations during tocolysis

AIMS

The present study was carried out to assess the effect of the selective beta2-adrenoceptor agonists on erythropoietin (EPO) production.

METHODS

Routine tocolysis with fenoterol (using the regular rate of 2 microg min[-1]) was used as a clinically easily accessible model.

RESULTS

EPO concentrations had doubled 24 h after the start of tocolysis (P < 0.001). This increase lasted over the entire observation period of 48 h. Potassium concentrations fell significantly during the first hours of fenoterol infusion. There was no increase of human placenta lactogen during the period of EPO increase.

CONCLUSIONS

The data confirm our earlier results that fenoterol increases EPO concentrations following haemorrhage. In this model it was not necessary to stimulate EPO production prior to pharmacological treatment.

Molecular characterization of Borna disease virus from naturally infected animals and possible links to human disorders

In this review data are presented which indicate a high degree of genetic stability of BDV in his natural host, the horse. Despite this high degree of sequence conservation, variation in antigenicity was found, which did not influence the pathogenic properties of the virus. In addition, the correlation between BDV-seropositivity and a variety of psychiatric and neurological disorders in humans is discussed. In diagnostically unselected psychiatric patients we found a similar distribution of psychiatric disorders in BDV seropositives compared to seronegatives. Investigations of cerebrospinal fluid revealed cases of BDV encephalitis in BDV seropositive psychiatric and neurological patients. In contrast to others, we have found no evidence for the presence of BDV-RNA or BDV in human peripheral blood leucocytes.

[Pathogenicity of Borna disease virus in psychiatric and neurologic disorders of humans. Current status of research and critical comments]

Demonstration of BDV-specific serum antibodies, the isolation of BDV from cerebrospinal fluid of neuropsychiatric patients, and the recent demonstration of BDV antigen and BDV-RNA in human brain tissues strongly suggest that BDV can infect humans. Isolation of BD virus from brain tissue is needed for final proof. There is still great controversy about the question of whether BDV antigen, BDV-RNA or BDV can be detected in peripheral blood monocytes or not. Overall, the question of pathogenicity of BDV infection for humans is wide open. Investigations of human cerebrospinal fluid indicate that BDV might cause human lymphocytic meningoencephalitis and so-called symptomatic psychoses in rare cases. Seroepidemiological studies suggest a widely non-specific but possibly pathogenic role of BDV in a spectrum of psychiatric disorders.

Failure to detect Borna disease virus infection in peripheral blood leukocytes from humans with psychiatric disorders

The presence of antibodies reactive with Borna disease virus (BDV) in the sera of some patients with certain psychiatric illnesses has been taken as evidence that this veterinary neurotrophic virus may occasionally infect and cause psychiatric disorders in humans. In this paper, we report the results of our studies concerning the detection of BDV-specific RNA in blood cells from patients with psychiatric diseases. Contrary to the results obtained by others, we have found no evidence for the presence of BDV-RNA in such cells. Prior work with BDV sequences in the assay environment, together with the exquisite sensitivity of RT-PCR, may account for the sporadic appearance of false positive evidence that BDV-specific RNA is present in human blood cells.

Lack of association of Borna disease virus and human T-cell leukemia virus type 1 infections with psychiatric disorders among Japanese patients

Borna disease virus (BDV) infection has been suspected to be a possible etiological factor in human psychiatric disorders and recently in chronic fatigue syndrome. Evidence of the correlation of BDV infection with these disorders remained unclear. Kagoshima is known to be one of the major areas in which human T-cell leukemia virus type 1 (HTLV-1) is endemic; this is the first isolated human retrovirus that causes adult T-cell leukemia with neurological symptoms. The present study aimed to clarify whether BDV and HTLV-1 infections are associated with psychiatric disorders among Japanese patients. Subjects were 346 patients with psychiatric disorders (schizophrenia, 179; mood disorder, 123; and others, 44) and 70 healthy controls. Anti-BDV antibodies from plasma samples were screened by the indirect immunofluorescence (IF) method using BDV-infected MDCK cells. Results revealed that only three samples were found to be weakly positive for BDV in the IF assay and seronegative by Western blot (immunoblot) assay. Furthermore, BDV-p24 related RNA in peripheral blood mononuclear cells from 106 of 346 psychiatric patients and 12 or 70 healthy controls by p24-reverse transcription PCR was examined. Two mood disorder patients were positive for BDV-p24 RNA but seronegative. To detect anti-HTLV-1 antibodies the plasma samples were screened by the particle agglutination method and no significant difference in seropositivity for anti-HTLV-1 antibody was found between the patients and healthy controls. These results also suggested that there is a lack of association between BDV and HTLV-1 infections with psychiatric disorders among Japanese patients.

Borna disease virus infection in animals and humans

The geographic distribution and host range of Borna disease (BD), a fatal neurologic disease of horses and sheep, are larger than previously thought. The etiologic agent, Borna disease virus (BDV), has been identified as an enveloped nonsegmented negative-strand RNA virus with unique properties of replication. Data indicate a high degree of genetic stability of BDV in its natural host, the horse. Studies in the Lewis rat have shown that BDV replication does not directly influence vital functions; rather, the disease is caused by a virus-induced T-cell mediated immune reaction. Because antibodies reactive with BDV have been found in the sera of patients with neuropsychiatric disorders, this review examines the possible link between BDV and such disorders. Seroepidemiologic and cerebrospinal fluid investigations of psychiatric patients suggest a causal role of BDV infection in human psychiatric disorders. In diagnostically unselected psychiatric patients, the distribution of psychiatric disorders was found to be similar in BDV seropositive and seronegative patients. In addition, BDV-seropositive neurologic patients became ill with lymphocytic meningoencephalitis. In contrast to others, we found no evidence is reported for BDV RNA, BDV antigens, or infectious B DV in peripheral blood cells of psychiatric patients.

[Obstetric aspects of maternal hepatitis C infection]

The present study discusses problems of maternal infection with hepatitis C virus in pregnancy with respect to the recent publications on this subject. In particular, questions of vertical transmission during pregnancy and fetal infection sub partu are discussed using three cases as an example. It was shown that recently few informations on the risk of transmission of the hepatitis C virus from the mother to the infant in utero or sub partu are existing, but the actual studies provide some evidence for this risk to be relatively low. The actual knowledge concerning the mode of delivery of hepatitis C positive women as well as recommendations concerning the diagnostic and therapeutic procedures are comprehensively shown on the basis of the recent scientific results.

Pricing in computer networks

As the Internet makes the transition from research testbed to commercial enterprise, the topic of pricing in computer networks has suddenly attracted great attention. Much of the discussion in the network design community and the popular press centers on the usage-based vs. flat pricing debate. The more academic literature has largely focused on devising optimal pricing policies; achieving optimal welfare requires charging marginal congestion costs for usage. In this paper we critique this optimality paradigm on three grounds: (1) marginal cost prices may not produce sufficient revenue to fully recover costs and so are perhaps of limited relevance, (2) congestion costs are inherently inaccessible to the network and so cannot reliably form the basis for pricing, and (3) there are other, more structural, goals besides optimality, and some of these goals are incompatible with the global uniformity required for optimal pricing schemes. For these reasons, we contend that the research agenda on pricing in computer network should shift away from the optimality paradigm and focus more on structural and architectural issues. Such issues include allowing local control of pricing policies, fostering interconnection, handling multicast appropriately, and allowing receivers to pay for transmission. To illustrate our point, we describe how these goals might be accomplished in the context of a different pricing paradigm: edge pricing. In addition, we argue that in the context of this edge pricing paradigm, usage-based pricing and flat pricing are not radically different but instead both reside along the single continuum of usage-constraining pricing policies.

[Successful therapy of heparin-associated thrombocytopenia with a low sulfated heparinoid]

Heparin-associated thrombocytopenia (HAT) is a relative frequent complication of thromboembolic prophylaxis and therapy. There is good evidence that the more severe HAT Type II is caused by an antibody dependent on polysulfated oligosaccharide epitopes. At present, low molecular weight heparins are used with varying success in patients with HAT that require further anticoagulation, although there are several known cases of cross reactivity between standard and low molecular weight heparins. Using our present case as an example, we show that the In-vitro- diagnostic of cross-reactivity is an indispensable precondition for any sufficient therapy. Additionally, we give support to previous findings that the low-grade sulfated heparinoid Org 10,172 shows no (or less) cross reactivity with standard or low molecular weight heparins. Thus, it might be the most appropriate choice if an anticoagulation is necessary before the results of In-vitro-diagnostics are available.

Induction of protection against Borna disease by inoculation with high-dose-attenuated Borna disease virus

Borna disease is a chronic neurological disease caused by an enveloped negative-strand RNA virus (BDV). Experimental disease can be reproduced in rats with brain homogenates derived from infected animals or with virus derived from infected cells in culture. The virus replicates in cultured cells without evidence of cytopathic effect or production of significant levels of cell-free virus. Borna disease is caused by an immunopathological response to viral infection of neural cells. To further investigate the pathogenesis of Borna disease, rats were inoculated with different doses of BDV attenuated by culture in MDCK cells. Low doses of attenuated BDV (10(2)-10(4) TCID50) resulted in typical clinical disease and severe encephalitis; however, the lag period between inoculation and disease was considerably longer than that with virulent BDV. In contrast, animals inoculated with a high dose of attenuated BDV (10(5)-10(6) TCID50) did not develop clinical disease, although a mild encephalitic response was present that did not progress beyond the mild encephalitis. Animals inoculated with a high dose of BDV developed high titers of anti-BDV antibody and were protected against virulent challenge. Protection was correlated with the rapid induction of an immune response in the animals and the lack of any biologically detectable virus in the CNS.

[Comparative study of maternal side effects of various forms of intravenous therapy with fenoterol in premature labor]

OBJECTIVE

The aim of the present study was to compare different regimes of intravenous fenoterol tocolysis concerning their side effects.

METHODS

A total of 59 patients with intravenous tocolysis due to preterm labor has been studied. They were chronologically alternating and thus randomly stratified into three groups: (a) continuous i.v.-tocolysis and oral application of magnesium sulfate (b) continuous i.v-tocolysis and i.v.-application of magnesium sulfate (c) pulsatile i.v.-application of fenoterol (bolus tocolysis) and oral application of magnesium sulfate. For all groups, heart rate, systolic and diastolic blood pressure, need for beta-blockers, K+, water balance over 24 hours as well as different subjective side effects were quantified.

RESULTS

The side effects were found to be significantly less among patients treated with bolus tocolysis and they were also found to be slightly less in continuous tocolysis with i.v.- application of magnesium compared to continuous tocolysis with oral Mg2+ substitution; however, the difference between the two groups treated with continuous tocolysis was not significant.

CONCLUSION

The present results suggest that bolus tocolysis shows significantly less side effects compared to the continuous tocolysis and thus it should be favored in clinical practise.

An animal model for studying mechanisms in human temporomandibular joint disc derangement

PURPOSE

A method for producing disc displacement is presented in which remodeling events in the disc and posterior attachment (PA) are similar to those occurring in patients suffering from disc displacement (DD).

METHOD

Thirty-three adult New Zealand White rabbits were used in this study. A unilateral anterior DD was surgically induced in 18 animals. Six animals were sham operated and nine animals served as controls.

RESULTS

Macroscopically, DD was associated with gross thickening of the posterior band (PB), shortening of the disc anteroposteriorly, flexure of the intermediate zone (IZ), and loss of the biconcave shape. Microscopically, dramatic internal structural changes were observed in displaced discs, including extensive collagenous fiber reorganization and changes in cell morphology associated with a generalized loss of metachromatic staining. As in humans, the disc displacement caused abnormal loading of the PA and remodeling of this tissue into a disc-like structure characterized by the appearance of coarse collagenous fiber bundles and scattered chondrocytes surrounded by a matrix-containing cartilage-like glycosaminoglycans (GAGs).

CONCLUSION

These pathoanatomic changes bear a remarkable similarity to those described in human disc derangements and support the use of this method as an experimental model for the study of remodeling events in human DD arthropathies.

Restriction fragment length polymorphisms of a chloroplast photosystem II gene from poplar and their use for species identification

In a total DNA library from the poplar clone Beaupré (Populus trichocarpa x P. deltoides) one DNA clone was found to identify restriction site polymorphisms in different poplar species. This clone represents a cpDNA gene that shows close homology to a photosystem II gene of pea and spinach coding for the D2 protein and the 44 kDa reaction centre. In Southern blot analysis this probe identified interspecific restriction site variation among the different poplar species; intraspecific variation was not detectable. As the chloroplast genome is maternally inherited in poplars this cpDNA probe was used for identification of P. nigra or P. deltoides as the seed parents of F1 hybrid trees in natural stands of western Germany.

[Expanded nuclear magnetic resonance studies in Borna disease virus seropositive psychiatric patients and control probands]

There is growing evidence, that Borna Disease virus (BDV) or a variant may cause neuropsychiatric disorders in humans. The presence of specific BDV serum antibodies indicates an earlier contact with BDV. Earlier MRI results showing a raised prevalence of white matter lesions in BDV-seropositive psychiatric patients, possibly indicating encephalitic lesions, are not confirmed in this extended study, however in BDV-seropositive psychiatric patients the occurrence of cerebral atrophy seems to be more frequent, a finding compatible with hydrocephalus e vacuo found in animals after BDV-encephalitis. Because encephalitic lesions in BD are predominantly found in the gray matter of the brain, which is hardly visualized by MRI, the failure to detect lesions in BDV-seropositive patients could be due to methodological problems.

Autoimmunity caused by host cell protein-containing viruses

Autoreactive T cells specific for myelin basic protein (MBP), a major component of central nervous system (CNS) protein, are frequently found in blood and cerebrospinal fluid of patients with postinfectious encephalomyelitis. This autoimmune syndrome is a CNS complication after infections with a number of different enveloped viruses, e.g. mumps, measles, rubella, influenza and varicella. However, the pathophysiological mechanism leading to this breaking of natural self tolerance in the course of viral infection remains an enigma. A long-lasting hypothesis has suggested that incorporation of cellular (self) proteins into the envelope of budding viruses might be a possible mechanism leading to autosensitization. In a model study we demonstrate here that vesicular stomatitis virus (VSV), grown in myelin protein-expressing cell cultures, is highly efficient in triggering T cell responses to MBP in vitro and can prime autoreactive T cell immune responses in vivo. On the basis of these findings, we suggest that incorporation of CNS membrane components into the viral envelope and subsequent priming of self-reactive immune responses might be the common pathogenic mechanism underlying the postinfectious encephalomyelitis syndrome.

Demonstration of Borna disease virus-specific RNA in secretions of naturally infected horses by the polymerase chain reaction

The presence of Borna disease virus (BDV)-specific RNA was traced by the reverse transcriptase-polymerase chain reaction in conjunctival fluid, nasal secretions and saliva of horses which were seropositive but did not have any history of clinical Borna disease. Positive reactions encompassed sequences encoding the p24 BDV-specific protein. Virus specificity of the amplified product was confirmed by hybridization with the respective oligomer probe. Viral infectivity or virus-specific antigen was not found in any of these secretions by conventional assays in cell culture and immunoblotting.

T cell memory specific for self and non-self antigens in rats persistently infected with Borna disease virus

We have studied CD4+ Th1 T cell responses in Borna disease (BD), a virus-mediated immune disease of the central nervous system (CNS), and demonstrate the priming of virus-specific as well as autoreactive T cells specific for myelin antigens in the course of viral infection. The fate of these in vivo generated T cells was subsequently assessed by in vitro proliferation assays with lymphocytes from different lymphoid organs of diseased animals over a long period of time. Virus-specific T cell responses continuously decreased during the establishment of persistent infection and could no longer be detected after 5-6 months post infectionem, when inflammatory reactions in the brain had ceased. By contrast, autoantigen-specific T cells kept their ability to mount characteristic secondary responses--although at an overall rather low level--over long periods of time; these autoreactive T cells homed to a specific lymphoid organ, the perithymic lymph node. Our study thus describes for the first time a complete decline of virus-specific T cell memory in a persistent viral infection, and raises the question how long-lasting T cell autoreactivity is controlled.

Analysis of virus-specific RNA species and proteins in Freon-113 preparations of the Borna disease virus

Treatment of homogenates from Borna disease virus (BDV)-infected brain tissue or cell cultures with Freon-113 yielded infectious particles with a buoyant density of 1.16-1.22 g/ml. Positive- and negative-stranded BDV-specific RNA species as well as three virus-specific proteins, known to be present in BDV-infected cell extracts, were demonstrated in these Freon-treated fractions. When the Freon-purified virus preparations were treated with RNase A prior to RNA extraction, only negative-stranded, genomic RNA was detected in Northern blot hybridizations using sense and antisense RNA probes. These data substantiate that BDV is a negative-stranded RNA virus.

Borna disease virus: nature of the etiologic agent and significance of infection in man

This review presents data on the characterization of Borna disease virus (BDV) and its potential as a possible causative agent in humans. The isolation of: (i) BDV-specific cDNA clones that encode various BDV-specific proteins and (ii) partially purified virus particles led to the conclusion that the viral genome consists of negative-sense, single-stranded RNA. The organization of the BDV-specific RNA species appears to be a nested set of overlapping subgenomic RNA transcripts. Furthermore, evidence is presented that BDV can infect humans and may cause certain psychiatric and neurological disorders. This concept is supported by: (i) the finding of virus-specific antibodies in sera of patients with neuropsychiatric diseases and (ii) results obtained during attempts to isolate BDV or a BDV-related agent from the cerebrospinal fluid of seropositive patients.

Chromosome polymorphism in Ateles geoffroyi (Cebidae; Primates; Mammalia)

The karyotype of Ateles geoffroyi (Cebidae; Primates; Mammalia) was studied using G- and C-banding techniques, and standardized idiograms are proposed. A polymorphism of chromosome 3 due to a pericentric inversion has been identified for the first time. Genetic analysis of this polymorphism showed Mendelian inheritance.

Infection with Borna disease virus: molecular and immunobiological characterization of the agent

Borna disease virus (BDV), which seems to be distinct from all other known viruses, exhibits a unique mechanism of pathogenesis. This review highlights several aspects of the biology of infection with this virus and summarizes the preliminary characterization of the agent. Studies on BDV may help to illuminate several important areas of neurobiology, including the mechanisms regulating the replication of a new type of RNA virus in the nuclei of neural cells, the neuroinvasiveness and neurotropism of such viruses, their T cell-mediated immunopathology, tolerance in newborn animals to persistent viral infection of the central nervous system, and behavioral diseases and eating disorders induced by such agents.

The 24K protein of Borna disease virus

Based on partial amino acid sequences obtained from tryptic peptides of the purified 24K antigen of Borna disease virus (BDV), we identified and sequenced four independent cDNA clones established from BDV-infected MDCK cells. Each of the clones encodes a polypeptide of 201 residues (Mr 22461) that differs considerably from an amino acid sequence published recently. In vitro transcription/translation of both the wild-type and a 5' truncated clone lacking the first ATG codon yielded a peptide that comigrates on electrophoresis with a polypeptide immunoprecipitated from BDV-infected cells. The deduced amino acid sequence contains a putative signal for nuclear targeting.

Transferrin polymorphism and genetic differentiation in Cervus elaphus L. (European red deer) populations

A study of transferrin in 11 different European populations of Cervus elaphus as well as in one Cervus elephus x Cervus nippon hybrid population has revealed a polymorphism of this protein. Genetic analysis suggests that it is controlled by one gene locus with three codominant alleles. The allele frequencies allow a clear discrimination not only between the hybrid population and pure red deer but also between different Continental red deer populations. Comparison of the genotypic structures with the Hardy-Weinberg structure shows no significant deviation. Genetic variation within and differentiation between populations is evaluated for the transferrin gene locus using different measures. Average heterozygosities have been calculated for five populations including the results of previous studies on 14 other protein systems. Some management implications of the present results are discussed.

Borna disease, a possible hazard for man?

Evidence is presented that Borna disease (BD) virus, which is known to cause encephalopathy in horses, sheep, and a broad range of experimental animals, or a related agent, can infect man and may induce mental disorders. BD virus-specific antibodies could be demonstrated in 4-7% of sera (depending on origin) from more than 5000 psychiatric or neurological patients from Germany, U.S.A. and Japan. Antibodies from seropositive patients reacted with a BD virus-specific protein translated by RNAs which were transcribed from a cDNA clone obtained from BD virus-infected tissues. When the cerebrospinal fluid from three seropositive patients was inoculated into rabbits or rabbit embryonic brain cell cultures, evidence was obtained that suggests the presence of BD virus or a related agent.