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Biomedical subjects

H Ludwig

Publications and source records attributed to H Ludwig.

At least 109 records · Page 6Linked to original sources
PubMed1997

The glycosylated matrix protein of Borna disease virus is a tetrameric membrane-bound viral component essential for infection.

Borna disease virus (BDV) is representative of the family of Bornaviridae in the order Mononegavirales (negative-stranded, non-segmented, enveloped RNA viruses). It is the causal agent for Borna disease, characterized as an encephalomyelitis (typical form) in a wide variety of domestic animals (from rodents to birds). Recent information shows the involvement of BDV in the pathogenesis of some human psychiatric disorders. The 8.9-kb viral antigenome codes for five major ORF. The third ORF codes for a 16-kDa protein (matrix protein) that is posttranslationally modified, yielding an N-linked glycoprotein. Our data show that the glycosylated matrix protein exists as a stable tetrameric structure detectable either by electrospray ionization or matrix-assisted laser-desorption ionization mass spectrometry. Under native conditions, the tetramer, with a relative molecular mass of 68 kDa, was isolated from a sediment-free brain suspension of a BDV-infected horse. The 68-kDa entity is stable in the presence of ionic and nonionic detergents but dissociates into subunits when heated. We found that the tetrameric matrix protein inhibits in vitro BDV infection in a dose-dependent manner. In contrast to inhibition of BDV infection with hydrophobic carbohydrate derivatives and protein-bound glycoconjugates, the glycosylated matrix protein is a very potent inhibitor of BDV infection, indicating that this protein represents an essential virus-specific membrane component for viral attachment.

Animals↗
PubMed1997

Clinical similarities and close genetic relationship of human and animal Borna disease virus.

Borna disease virus (BDV) is the prototype genus of a new family, Bornaviridae, within the order Mononegavirales. BDV naturally infects animals and man. The symptomatology in animals ranges from subclinical infection to rare cases of encephalitis. Asymptomatic infection seemed more frequent than expected, based on antibody data from 100 healthy horses derived from different stables with a history of diseased cases (30-40% carriers). Likewise, phasic episodes of a neurobehavioral syndrome followed by recovery were much more common than fatal neurologic disease. They were paralleled by expression of BDV antigens (N-protein p40, P-protein p24) and RNA transcripts in peripheral blood mononuclear cells, indicating viral activation. Representative longitudinal studies showed that episodes of depressive illness in humans as well as apathetic phases in infected horses were accompanied by antigen expression and followed a similar clinical course. After recovery, BDV antigen disappeared. This temporal congruence, together with the recent isolation of infectious BDV from such patients, points to a contributory role of this virus in human affective disorders. Successful amelioration of BDV-induced neurobehavioral disease in horses with antidepressants applied in psychiatry, supported a common viral pathomechanism, involving reversible disturbances of the neurotransmitter network in the limbic system. Sequences of genetic material amplified from infected animal tissue and human PBMCs revealed a close interspecies relationship and high sequence conservation of the BDV genome. In human BDV isolates, however, single unique mutations were prominent in four genes. This finding supports the hypothesis that despite of high genomic conservation, species-specific genotypes may be definable, provided the sequences are derived from RNA of infectious virus.

Aged↗
PubMed1997

Neurological disease and encephalitis in cats experimentally infected with Borna disease virus.

Barrier-bred cats were inoculated intracerebrally with either the rabbit-adapted Borna disease virus (BDV) strain V or a newly isolated feline BDV, obtained from a cat with natural staggering disease (SD). Three out of eight inoculated cats developed neurological signs and non-suppurative encephalitis; all three recovered from the acute stage of disease. Sero-conversion and the development of neutralizing antibodies occurred in all of the virus-inoculated cats. In addition, cats inoculated with feline BDV showed an early peripheral T cell response not present in cats inoculated with BDV strain V, suggesting that the feline virus exerted a more vigorous effect on the immune system. Using immunohistochemistry and a reverse transcriptase-polymerase chain reaction assay, BDV-specific antigen and nucleic acid could be demonstrated in brain samples from each cat with encephalitis, showing that incomplete viral clearance was probably responsible for the maintenance of inflammation. The successful induction of neurological signs and encephalitis in one cat infected with feline BDV, together with the detection of BDV-specific antigen and nucleic acid in the brain, provides strong evidence for the notion that BDV is the etiological agent behind feline SD.

Animals↗
PubMed1997

Distribution and relevance of equine herpesvirus type 2 (EHV-2) infections.

Equine herpesvirus type 2 (EHV-2) is a slow-growing, cytopathogenic gammaherpesvirus, which is suggested to be ubiquitous in the equine population. However, its precise role as a pathogen and its tissue tropism remains uncertain. To estimate the prevalence of EHV-2 in Germany and to investigate the possible pathogenicity of the virus, peripheral blood leucocytes (PBL) from 172 horses were examined for EHV-2 DNA by a sensitive and specific nested PCR based on the EcoRI-N genomic fragment and by classical cocultivation. PBL samples from 51% of the horses were positive by PCR and virus was isolated from 31% of the horses by cocultivation. However, almost all animals were seropositive for EHV-2. This may indicate that PBL do not harbour EHV-2 indefinitely after infection. Furthermore, a correlation between clinical signs and EHV-2 as a causative agent could not be determined. Nevertheless, the prevalence of virus was high among horses with upper respiratory tract disease, abortion and severe ataxia. The products of the second round of the PCR reactions showed size polymorphism. Sequencing of the products revealed that these size differences were due to repetition of the motif (AGACAGGGGCCATGCTGGC) between 9-16 times depending on the isolate, suggesting that the nested PCR might be a useful tool for the differentiation of EHV-2 isolates.

Animals↗
PubMed1997

Interferon-alpha-2C and LD ara-C for the treatment of patients with CML: results of the Austrian multi-center phase II study.

Small pilot studies of patients with CML have reported on encouraging response rates after treatment with interferon-alpha (IFNalpha) in combination with low-dose cytosine arabinoside (LD ara-C). We therefore initiated a multi-center phase II trial in order to investigate the efficacy and tolerability of this combination in newly diagnosed patients with Ph-positive chronic myelogenous leukemia (CML). Eighty-four patients were treated with IFN-alpha-2c at daily subcutaneous doses of 3.5 MU and LD ara-C added subcutaneously for 10 days every month at a dose of 10 mg/m2, following an initial reduction of WBC to less than 20 x 10(9)/l with hydroxyurea (HU). Within a median observation period of 28 (5-59) months the patients received a median of 7 (1-35) IFNalpha and LD ara-C cycles. Treatment was stopped due to side effects in 16 cases (19%) and to primary or secondary treatment failure in 38 cases (45%). In 45 patients (54%) complete hematological response (CHR) was achieved; in 39 patients (46%) cytogenetic responses including 15 (18%) complete cytogenetic responses (CHR) were observed. Median duration of cytogenetic responses was 15 months. Relapses were seen in 8/15 patients (53%) with complete cytogenetic remission (CCR), in 3/6 patients (50%) with partial cytogenetic response and in 9/18 patients (50%) with minor cytogenetic response. In conclusion, the combination of IFNalpha and LD ara-C resulted in encouraging rates of hematological and cytogenetic responses in patients with CML with low to moderate toxicity.

Adolescent↗
PubMed1997

Equine herpesvirus 4 DNA in trigeminal ganglia of naturally infected horses detected by direct in situ PCR.

Neuronal and lymphoid tissues of 15 randomly selected horses were analysed post mortem by liquid nested-PCR to study the tropism of equine herpesvirus 4 (EHV-4). In four animals the trigeminal ganglia and in one case the lung were positive. Using a direct in situ PCR the EHV-4 genome was localized in the nuclei of neurons and in the bronchiolar as well as alveolar epithelium of the lung. In none of these tissues could infectious virus or viral antigens be detected. Applying the more sensitive liquid RT-PCR, however, an acute infection was demonstrated in one of the trigeminal ganglia by amplification of viral transcripts coding for glycoprotein B. The failure to detect these transcripts in the other trigeminal ganglia and the lung indicates a latent infection. This report formally proves that, like other members of the Alpha-herpesvirinae, EHV-4 establishes latency in the trigeminal ganglia.

Animals↗
PubMed1997

Borna disease virus (BDV), a (zoonotic?) worldwide pathogen. A review of the history of the disease and the virus infection with comprehensive bibliography.

A comprehensive history of Borna disease virus (BDV) and this infection, including the complete bibliography, is presented. Over the last 200 years, descriptions of this 'head disease' of horses ('Kopfkrankheit der Pferde') have been given. Considerable losses in the horse population (< 0.8%) led to intensive clinical and (neuro-)pathological investigations of this meningitis cerebrospinalis which occurs with faint behavioural changes, occasionally followed by severe neurological symptomatology and death. The broad experimental host range reflects infections in nature which include horses, sheep, cattle, cats, dogs, rodents, ostriches, and some zoo animals. BDV infections are associated with phylogentically old brain areas, and the retina. Occasionally, expression in the autonomic nervous system occurs, besides its neurotropism BDV can spread to peripheral organs, especially to epithelial tissues and peripheral blood mononuclear cells. Infections of humans that can be monitored by antibodies, antigens or nucleic acids in blood samples are prominent features of future interest. BDV, the prototype of the family Bornaviridae is an enveloped spherical virus carrying an 8.9 kb single-stranded, non-segmented RNA with negative polarity which replicates in the nucleus. These features together with its considerable genetic stability make this non-cytopathogenic virus an evolutionary 'old pathogen' in nature.

Animals↗
PubMed1997

The neuropathogenesis of Borna disease virus infections.

The unique genetic and biological properties of this small enveloped RNA virus indicate that Borna disease virus (BDV) is an evolutionary old pathogen. It appears perfectly adapted to persist inside the limbic system, a most delicate and sensitive old area of the mammalian brain involved in the control of mood, behavior, and memory. In many infected individuals, BDV remains a commensal during their lifetime. In a minority of vulnerable subjects, BDV becomes frequently activated, leading to episodes of distinct, more or less severe disturbances of information processing, behavioral and mood alterations. BDV research in humans is anticipated to initiate new insights into the interplay of exogenous and endogenous factors governing mood disorders. In nature BDV preferentially behaves as a neurotropic virus, but may latently and/or persistently infect cells of the reticuloendothelial system. This has been shown to be of great diagnostic importance, because now BDV 'footprints' can be followed in vivo in animals and man. BDV, which has long been considered as a classical animal virus, is present in humans, and has been found to be associated with some defined psychiatric disorders in particularly vulnerable individuals. An interaction of BDV proteins with neurotransmitter activities is plausible in the light of experimental animal data. Interference with normal behavior and the influence on mood and cognitive functions as demonstrated in animals and assumed in humans require extensive future research on the molecular etiopathogenesis. Aside from these clinical aspects, BDV is an unusual agent with outstanding features, namely replication in the nucleus of its target cells by an elusive, partially unknown mechanism, showing no cytopathogenicity or disturbance of vital cell functions, but altering luxury functions, and with a lifelong persistence giving rise to periods of long latency and short activation.

Animals↗
PubMed1997

Patient preferences for interferon alfa in multiple myeloma.

PURPOSE: Interferon alfa treatment in multiple myeloma marginally improves relapse-free and overall survival. Often it does so at the expense of toxicity and financial cost. If patients are unwilling or unable to participate in the decision of whether to initiate such treatment, known patient preferences can serve as guidelines for the physician. We interviewed myeloma patients in the United States to obtain information that might facilitate medical decision-making. PATIENTS AND METHODS: Three hundred fifty-five myeloma patients throughout the United States were interviewed by telephone. Without identifying interferon alfa as the treatment agent, interviewers described potential adverse effects, financial cost, and self-injection procedures. The potential benefits of four treatment choices, derived from a meta-analysis of published data, were presented as gains in remission rate (+10%), remission duration (an additional 4 and 7 months, respectively, for induction and maintenance treatment), and overall survival (an additional 3 and 6 months, respectively, for induction and maintenance treatment). Patients' choices for or against use of the unidentified substance were recorded, and interferon was subsequently disclosed as the treatment. The profiles of patients making different choices were determined using multivariate regression techniques. RESULTS: Approximately half of the patients accepted the unidentified treatment if remission and/or survival improved by at least 6 months. Accepters were younger and more likely to have used interferon. Of patients who rejected the unidentified treatment, 25% to 50% would have been willing to accept it if the benefits were > or = 12 months. Test/retest reliability of all choices, determined in 36 cancer patients, was 0.896. CONCLUSION: In multiple myeloma, interferon therapy and, by inference, other treatments with comparable features are acceptable to approximately half of the patients if a 6-month gain in relapse-free or overall survival can be expected.

Adult↗
PubMed1997

Optimized Fast-FISH with alpha-satellite probes: acceleration by microwave activation.

It has been shown for several DNA probes that the recently introduced Fast-FISH (fluorescence in situ hybridization) technique is well suited for quantitative microscopy. For highly repetitive DNA probes the hybridization (renaturation) time and the number of subsequent washing steps were reduced considerably by omitting denaturing chemical agents (e.g., formamide). The appropriate hybridization temperature and time allow a clear discrimination between major and minor binding sites by quantitative fluorescence microscopy. The well-defined physical conditions for hybridization permit automatization of the procedure, e.g., by programmable thermal cycler. Here, we present optimized conditions for a commercially available X-specific alpha-satellite probe. Highly fluorescent major binding sites were obtained for 74 degrees C hybridization temperature and 60 min hybridization time. They were clearly discriminated from some low fluorescent minor binding sites on metaphase chromosomes as well as in interphase cell nuclei. On average, a total of 3.43 +/- 1.59 binding sites were measured in metaphase spreads, and 2.69 +/- 1.00 in interphase nuclei. Microwave activation for denaturation and hybridization was tested to accelerate the procedure. The slides with the target material and the hybridization buffer were placed in a standard microwave oven. After denaturation for 20 sec at 900 W, hybridization was performed for 4 min. at 90 W. The suitability of a microwave oven for Fast-FISH was confirmed by the application to a chromosome 1-specific alpha-satellite probe. In this case, denaturation was performed at 630 W for 60 sec and hybridization at 90 W for 5 min. In all cases, the results were analyzed quantitatively and compared to the results obtained by Fast-FISH. The major binding sites were clearly discriminated by their brightness.

Chromosomes↗
PubMed1997

Immunohistochemical evaluation of cathepsin D expression in colorectal cancer.

Determination of cathepsin D has been proven to be prognostically relevant in breast cancer. Cathepsin D, a lysosomal proteinase, is suggested to be causally involved in tumor invasion. In this study we investigated cathepsin D expression immunohistochemically in 106 colorectal adenocarcinomas with the intention to evaluate its prognostic significance in this type of cancer. The majority of colorectal adenocarcinomas (93/106) stained positive for cathepsin D, while normal colon was almost completely negative. A trend toward stronger staining intensity was found in Dukes' stage C and D tumors (p < 0.1), but cathepsin D expression was found to have no influence on survival in this tumor type nor did it correlate with other known prognostic factors, e.g., histological differentiation, lymph vessel invasion, or rate of proliferation. Staining of lymph node metastases did not differ significantly from that of their primary tumors. Stronger staining intensity of tumor tissue in the neighborhood of inflammatory cells may be due to paracrine activation.

Adenocarcinoma↗
PubMed1996

Optimization of Fast-FISH for alpha-satellite DNA probes.

It has been shown for several highly repetitive DNA probes that the newly introduced Fast-FISH (fast-fluorescence in situ hybridization) technique is well suited for quantitative microscopy. The advantage of omitting denaturing chemical agents (e.g., formamide) in the hybridization buffer results in a short hybridization time and a considerable reduction of the number of subsequent washing steps. Choosing the appropriate hybridization temperature and time allows to clearly discriminate major and minor binding sites by quantitative fluorescence microscopy. To further optimize the procedure with reference to reproducibility, a fully programmable thermal-cycler was applied for thermal de- and renaturation. Here, the optimized renaturation conditions for two commercially available alpha-satellite probes (specific for chromosomes 1 and X) are described. For the Boehringer chromosome-1-specific DNA probe, two highly fluorescent binding sites were obtained for 72 degrees C hybridization temperature and 60 min hybridization time. For the Oncor chromosome-X-specific DNA probe, the optimal conditions were found at 74 degrees C and 60 min hybridization time. In both cases the major binding sites were clearly discriminated from only a few weakly fluorescent minor binding sites on metaphase spreads as well as in interphase cell nuclei.

DNA Probes↗
PubMed1996

Administration of the bisphosphonate ibandronate (BM 21.0955) by intravenous bolus injection.

Bisphosphonates (BPs) are used for the treatment of both benign and malignant diseases characterized by increased bone resorption. Because of their potential nephrotoxicity, currently available BPs have to be administered by slow intravenous infusion, with conventional doses requiring an infusion time of at least 2 h. In the present investigation, we evaluated the safety and efficacy of the new BP ibandronate as administered by intravenous bolus injection. On day 0, 15 normocalcemic breast cancer patients with bone metastases were treated with 3 mg of ibandronate injected intravenously over 60-120 s. Ibandronate treatment led to significant decreases in serum levels of calcium (p < 0.0001) and phosphate (p < 0.0001) and to subsequent increases in serum concentrations of parathyroid hormone (p <0.0001) and calcitriol (p <0.0001). Moreover, there was a significant reduction in the urinary excretion of calcium (p <0.0001), pyridinoline (p <0.001), and deoxypyridinoline (p < 0.0001). Three serious adverse events were observed: vomiting (WHO grade 3), pulmonary infection (WHO grade 2), and deterioration of a pre-existing impaired glucose tolerance (WHO grade 3). Only vomiting appeared to be related to administration of the drug. The most frequent nonserious adverse events were 10 cases of transient clinically asymptomatic hypocalcemia and 8 cases of asymptomatic hypophosphatemia. Serum levels of creatinine and urea nitrogen did not increase, nor did creatinine clearance deteriorate. When tested with the dipstick method, proteinuria was present in five (33%) patients prior to ibandronate treatment (median protein concentration, 30 mg/dl). Following the BP injection, seven (47%) patients showed slight (highest protein concentration, 30 mg/dl) transient proteinuria at at least one time point, of which six cases appeared in conjunction with leucocyturia and three with microhematuria. Side effects specific to aminosubstituted BPs (fever, reduction in white blood cell counts, and lymphocyte counts) were not seen in these 15 patients. In conclusion, a single intravenous injection of 3 mg of ibandronate significantly inhibited osteoclast activity as reflected by the decrease in serum calcium and in urinary parameters of bone resorption. Serum creatinine levels and estimates of creatinine clearance were not affected by therapy. However, before repeated bolus injections of ibandronate at this dosage can be recommended for further clinical trials, whether a relationship exists between the transient pathological urinary findings and injected ibandronate needs to be determined.

Aged↗
PubMed1996

Maximal androgen blockade in combination with methotrexate for treatment of metastatic prostate cancer.

Recently attention has been focused on the optimal timing of chemotherapy within the treatment regimen for patients with metastatic prostate cancer, i.e., hormonal manipulation, preferably maximal androgen blockage (MAB) consisting of chemical/surgical castration followed by treatment with antiandrogens. We have conducted a randomized prospective clinical trial, investigating the efficacy and toxicity of MAB (orchiectomy followed by flutamide therapy) alone as compared to MAB combined with methotrexate (MTX, 50 mg/m2/week) in 53 patients with newly diagnosed stage IV(M1) prostatic cancer (UICC TNM Classification 1987). The observed remission rates (complete + partial) of 42.3% in the MAB + MTX arm and 29.6% in the MAB arm did not differ significantly. The response rates (complete + partial + stable disease) of 73.1% and 66.7% for MAB + MTX and MAB respectively, also showed no significant difference. Neither progression-free survival (median 18/5 and 23.8 months for MAB + MTX and MAB, respectively) nor overall survival (median: 37.4 and 36.1) months in the MAB + MTX and MAB arm, respectively) could be improved by the addition of MTX to MAB Only the extent of metastatic pain reported by the patients was consistently less under MAB + MTX than under MAB alone (P<0.1). Both treatment regimens were well- tolerated with slightly more undesirable effects in the MAB + MTX arm. Our results do not provide evidence for the achievement of marked gains by combining chemotherapy with endocrine therapy in newly diagnosed patients with stage IV (M1) prostate cancer.

Aged↗
PubMed1996

Sequence characterization of human Borna disease virus.

Borna disease virus (BDV) causes a central nervous system disease in several vertebrate animal species, which is manifest by behavioral abnormalities. Seroepidemiologic data suggest that BDV might infect humans, possibly being associated with certain mental disorders. This is further supported by the detection of both BDV-specific antigens and RNA sequences in peripheral blood mononuclear cells (PBMCs) of psychiatric patients. For the first time the sequence characterization of human BDV is documented here. BDV was recovered by co-cultivation techniques from the PBMCs of three hospitalized psychiatric patients. BDV was unequivocally identified based on sequence identification of BDV open reading frames (ORFs) p24, p16 and p56, as well as of the predicted catalytic domain of the BDV L polymerase. Each human BDV isolate had an unique sequence, but they displayed a high degree of sequence conservation with respect of BDV isolates from naturally infected animals of different species.

Adult↗
PubMed1996

Neoadjuvant chemotherapy (MVAC) in locally invasive bladder cancer.

In order to evaluate the efficacy of neoadjuvant chemotherapy in invasive urothelial carcinoma of the bladder a retrospective analysis was performed. 54 patients without distant metastases (T2-T3b, N0-X, M0) received 3 cycles of neoadjuvant chemotherapy according to the MVAC protocol (methotrexate, vinblastine, doxorubicin and cisplatin) after transurethral resection (TUR) followed by cystectomy. 52 patients had previously undergone cystectomy immediately after TUR. Complete histopathological remission was observed in 9 patients (17.3%) after TUR and in 17 patients (31.5%) after TUR+MVAC. Neoadjuvant MVAC resulted, therefore, in a 14% higher rate of complete remissions. The overall response to TUR was significantly improved by MVAC therapy. Downstaging by neoadjuvant chemotherapy was more readily achieved in initially low-stage tumours (T2: 44.4% and 30.8%, T3a: 47.1% and 19%, T3b: 5.3% and 5.5% in patients receiving TUR+MVAC and TUR alone, respectively). Overall survival did not differ significantly between both groups. Patients who were successfully downstaged to pT0 had a significantly better prognosis, and patients resistant to chemotherapy had the poorest prognosis, showing the shortest survival. In conclusion, histopathological response at cystectomy was improved by neoadjuvant MVAC chemotherapy after TUR and can be expected to be prognostically relevant in those patients who can be downstaged to T0, although overall survival failed to be significantly increased in this relatively small patient sample.

Aged↗