Search PubMed⌕ Search

Biomedical subjects

S Poser

Publications and source records attributed to S Poser.

At least 73 records · Page 4Linked to original sources
PubMed1999

Familial Creutzfeldt-Jakob disease with a novel 120-bp insertion in the prion protein gene.

The clinical course, neuropathological features, and genetic findings in 3 members of a German family carrying a novel 120-bp insertion in the prion protein (PrP) gene are described. Genetic analysis of the mutated allele revealed a sequence of five extra octapeptide repeats, distinct from those of the two previously reported families with an insertion of this size. There was distinctive variation in the clinical course and the onset and duration of the illness in the documented subjects. Neuopathological evaluation showed neuronal loss and gliosis in the neocortex of the 3 examined cases; spongiform degeneration was found in 2 of them. PrP immunoreactivity of unusual morphology and distinct distribution was present in the cerebellem and neocortex ("blurred staining") of 2 examined cases. One subject showed features usually found in sporadic Creutzfeldt-Jacob disease with a punctate type of PrP deposition in the cerebellum. In addition, there were some plaque-like PrP aggregates morophologically similar to the other 2 cases in the molecular layer of the cerebellum, and unusual Prp immunoreactivity ("fleecy staining") was found in the neocortex. The clinicopathological heterogeneity in the documented family is in accordance with the phenotypic variability associated with previously reported insertions.

Adult↗
PubMed1998

Case-control study of risk factors of Creutzfeldt-Jakob disease in Europe during 1993-95. European Union (EU) Collaborative Study Group of Creutzfeldt-Jakob disease (CJD).

BACKGROUND: Creutzfeldt-Jakob disease (CJD) is a transmissible spongiform encephalopathy. Genetic and iatrogenic forms have been recognised but most are sporadic and of unknown cause. We have studied risk factors for CJD as part of the 1993-95 European Union collaborative studies of CJD in Europe. METHODS: The 405 patients with definite or probable CJD who took part in our study had taken part in population-based studies done between 1993 and 1995 in Belgium, France, Germany, Italy, the Netherlands, and the UK. Data on putative risk factors from these patients were compared with data from 405 controls. FINDINGS: We found evidence for familial aggregation of CJD with dementia due to causes other than CJD (relative risk [RR] 2.26, 95% CI 1.31-3.90). No significant increased risk of CJD in relation to a history of surgery and blood transfusion was shown. There was no evidence for an association between the risk of CJD and the consumption of beef, veal, lamb, cheese, or milk. No association was found with occupational exposure to animals or leather. The few positive findings of the study include increased risk in relation to consumption of raw meat (RR 1.63 [95% CI 1.18-2.23]) and brain (1.68 [1.18-2.39]), frequent exposure to leather products (1.94 [1.13-3.33]), and exposure to fertiliser consisting of hoofs and horns (2.32 [1.38-2.91]). Additional analyses, for example stratification by country and of exposures pre-1985 and post-1985, suggest that these results should be interpreted with great caution. INTERPRETATION: Within the limits of the retrospective design of the study, our findings suggest that genetic factors other than the known CJD mutations may play an important part in CJD. Iatrogenic transmission of disease seems rare in this large population-based sample of patients with CJD. There is little evidence for an association between the risk of CJD and either animal exposure, or consumption of processed bovine meat or milk products for the period studied.

Adult↗
PubMed1998

Diagnosis of Creutzfeldt-Jakob disease by measurement of S100 protein in serum: prospective case-control study.

OBJECTIVE: To analyse serum concentrations of brain specific S100 protein in patients with Creutzfeldt-Jakob disease and in controls. DESIGN: Prospective case-control study. SETTING: National Creutzfeldt-Jakob disease surveillance unit. SUBJECTS: 224 patients referred to the surveillance unit with suspected Creutzfeldt-Jakob disease and 35 control patients without dementia. MAIN OUTCOME MEASURE: Serum concentration of S100 protein in patients with Creutzfeldt-Jakob disease, in patients with other diseases causing dementia, and in the control group. RESULTS: Of the 224 patients with suspected Creutzfeldt-Jakob disease, 65 were classed as definitely having the disease after neuropathological verification, an additional 6 were classed as definitely having the disease as a result of a genetic mutation, 43 as probably having the disease, 36 as possibly having the disease, and 74 patients were classed as having other disease. In the 108 patients classed as definitely or probably having Creutzfeldt-Jakob disease the median serum concentration of S100 was 395 pg/ml (SD 387 pg/ml). This was significantly higher than concentrations found in the 74 patients classed as having other diseases (median 109 pg/ml; SD 177 pg/ml; P = 0.0001). At a cut off point of 213 pg/ml sensitivity for the diagnosis of the disease was 77.8% (95% confidence interval 68.8% to 85.2%) and specificity was 81.1% (70.3% to 89.3%). There was a significant difference in survival at different concentrations of S100 in Kaplan-Meier curves (P = 0.023). CONCLUSION: Measurement of serum concentrations of S100 is a valuable tool which can be used more easily than tests on cerebrospinal fluid in the differential diagnosis of Creutzfeldt-Jakob disease. More studies are needed to determine whether serial testing of serum S100 improves diagnostic accuracy.

Biomarkers↗
PubMed1998

Detection of 14-3-3 protein in the cerebrospinal fluid supports the diagnosis of Creutzfeldt-Jakob disease.

The analysis of 14-3-3 protein in cerebrospinal fluid (CSF) was shown to be highly sensitive and specific for the diagnosis of Creutzfeldt-Jakob disease (CJD). However, the predictive value of this test in the clinical diagnosis of, and its relation to, sporadic, genetic, and iatrogenic CJD cases have yet to be established. CSF samples of suspect CJD cases seen in the prospective German surveillance study were tested for the presence of 14-3-3 protein by using a modified western blot (WB) technique. WB detected 14-3-3 protein in 95.4% of definite and 92.8% of probable cases. In two patients classified initially as not having CJD the test was positive, and both were later proved to have definite CJD. The positive predictive value is 94.7% and the negative predictive value is 92.4%. False-positive results in a single CSF analysis were seen in patients with herpes simplex encephalitis, hypoxic brain damage, atypical encephalitis, intracerebral metastases of a bronchial carcinoma, metabolic encephalopathy, and progressive dementia of unknown cause. WB analysis for 14-3-3 protein was positive in only 5 of 10 cases of familial forms of spongiform encephalopathies. CSF analysis for 14-3-3 protein should thus be performed in any case suspect for CJD.

14-3-3 Proteins↗
PubMed1998

Descriptive epidemiology of Creutzfeldt-Jakob disease in six European countries, 1993-1995. EU Collaborative Study Group for CJD.

After the occurrence of bovine spongiform encephalopathy (BSE), there has been concern that transmission of BSE to the human population might result in a change in the epidemiological characteristics of Creutzfeldt-Jakob disease (CJD). A collaborative study of CJD in the European Union was performed from 1993 to 1995, to compare data from national registries for CJD in France, Germany, Italy, The Netherlands, Slovakia, and the United Kingdom. Five hundred seventy-five patients with definite or probable CJD died in the study period with an overall annual mortality rate of 0.71 cases per million. The incidence rates for CJD were similar in all participating countries despite variations in postmortem rates, and age-specific incidence rates were also relatively consistent, with the exception of an increased incidence of CJD in patients younger than 39 years of age in the United Kingdom. In relation to etiological subtypes of CJD, 87% of cases were sporadic, 8% genetic, and 5% iatrogenic. Genetic forms of CJD comprised 80% of all cases in Slovakia, and iatrogenic forms of CJD occurred most frequently in France and the United Kingdom. The statistical data reported here do not provide evidence of a causal link between BSE and CJD in Europe as a whole. However, the study has established baseline epidemiological parameters for CJD in participating European countries, which may be important in the assessment of any future change in the characteristics of CJD as a result of the epidemic of BSE.

Adult↗
PubMed1998

Synergistic immunomodulatory effects of interferon-beta1b and the phosphodiesterase inhibitor pentoxifylline in patients with relapsing-remitting multiple sclerosis.

Subcutaneous application of interferon-beta1b (IFN-beta1b) is an established therapy for patients with relapsing-remitting multiple sclerosis (RRMS), but early side effects are still a major concern. In vitro studies with myelin basic protein (MBP)-specific T-cell lines revealed a synergistic suppressive effect of IFN-beta1b and the phosphodiesterase inhibitor pentoxifylline (PTX) on proliferation and the production of tumor necrosis factor-alpha (TNF-alpha), lymphotoxin (LT), and interferon-gamma (IFN-gamma). In an initial, open labeled prospective trial, the cytokine messenger RNA (mRNA) expression of blood mononuclear cells from MS patients, receiving either IFN-beta1b alone or in combination with oral PTX, was determined by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Patients treated with IFN-beta1b alone reported more side effects during the first 3 months of treatment and had upregulated TNF-alpha as well as IFN-gamma mRNA expression during the first month, which was not detected in patients receiving both drugs. A synergistic effect of both drugs was observed on the upregulation of interleukin (IL)-10 mRNA, which was accompanied by an increase in IL-10 serum levels. Both in vitro and in vivo data suggest that co-treatment of IFN-beta1b with PTX is a promising approach to correct the disturbed cytokine balance in MS patients.

Adjuvants, Immunologic↗
PubMed1998

Cross talk between ERK and PKA is required for Ca2+ stimulation of CREB-dependent transcription and ERK nuclear translocation.

Although Ca2+-stimulated cAMP response element binding protein- (CREB-) dependent transcription has been implicated in growth, differentiation, and neuroplasticity, mechanisms for Ca2+-activated transcription have not been defined. Here, we report that extracellular signal-related protein kinase (ERK) signaling is obligatory for Ca2+-stimulated transcription in PC12 cells and hippocampal neurons. The sequential activation of ERK and Rsk2 by Ca2+ leads to the phosphorylation and transactivation of CREB. Interestingly, the Ca2+-induced nuclear translocation of ERK and Rsk2 to the nucleus requires protein kinase A (PKA) activation. This may explain why PKA activity is required for Ca2+-stimulated CREB-dependent transcription. Furthermore, the full expression of the late phase of long-term potentiation (L-LTP) and L-LTP-associated CRE-mediated transcription requires ERK activation, suggesting that the activation of CREB by ERK plays a critical role in the formation of long lasting neuronal plasticity.

Animals↗
PubMed1998

[Elecroencephalographic charactistics of Creutzfeldt-Jakob disease and its differential diagnosis].

Although clinical electroencephalography is no longer as important as it used to be in differential diagnosis of a fair number of neurological and psychiatric diseases ever since imaging techniques have been making enormous strides, EEG is still an important diagnostic tool in dementias where specific morphological lesions are not immediately or not at all apparent which would otherwise be visible by imaging. Sporadic Creutzfeldt-Jakob disease is an important case in point. Although this is associated with some unspecific EEG findings, typical periodical sharp wave complexes (PSWC) become conspicuous in the course of the disease. If these are meticulously studied and particular attention is paid to their periodicity, a sensitivity of 67% and a specificity of 86% are attained. With the exception of one familial variant of Creutzfeldt-Jakob disease PSWC ar usually absent all other human prion diseases. Hence, it is not likely that they are linked to the aetiology of sporadic Creutzfeldt-Jakob disease. We present a patho-physiological hypothesis on the development of PSWC basing on the assumption that the specific periodicity of PSWC results from a still functionally active but greatly impaired subcortical-cortical circuit of neuronal excitability. This specific pattern of neuronal degeneration may obviously arise--albeit very rarely--also in other diseases independent of their aetiology, so that the EEG patterns appear identical. For this reason it is imperative to make complementary use of EEG and of recent clinical and laboratory data of Creutzfeldt-Jakob disease before PSWC and be considered a relevant diagnostic criterion. Conversely, clinical diagnosis of Creutzfeldt-Jakob disease should be reconsidered if repeated EEG recordings fail to reveal PSWC even under technically adequate conditions.

Creutzfeldt-Jakob Syndrome↗
PubMed1998

Akinetic mutism as a classification criterion for the diagnosis of Creutzfeldt-Jakob disease.

OBJECTIVES: Among the classification criteria for the diagnosis of Creutzfeldt-Jakob disease, akinetic mutism is described as a symptom which helps to establish the diagnosis as possible or probable. Akinetic mutism has been anatomically divided into two forms--the mesencephalic form and the frontal form. The aim of this study was to delimit the symptom of akinetic mutism in patients with Creutzfeldt-Jakob disease from the complex of symptoms of an apallic syndrome and to assign it to the individual forms. METHODS: Between April and December 1996, 25 akinetic and mute patients with Creutzfeldt-Jakob disease were consecutively examined. The patients were classified according to the definition of akinetic mutism by Cairns and secondly in accordance with the features constituting the complete picture of an appalic syndrome (defined by Gerstenbrand). RESULTS: From 25 patients with definite Creutzfeldt-Jakob disease, 24 patients showed impoverishment of speech and, after a mean duration of four (range 1.1-11.2) months, almost complete absence of voluntary movements and speech. Seven patients were classified as being mute and akinetic and assigned to the mesencephalic form whereas 13 patients were classified as apallic. One patient was mute without being akinetic and four patients were comatose. CONCLUSION: Diffuse brain damage underlies akinetic mutism in patients with Creutzfeldt-Jakob disease. The term can be used as a classification criterion for the diagnosis of Creutzfeldt-Jakob disease; however, it should be applied very carefully and delimited clearly from the apallic syndrome.

Adult↗
PubMed1998

Phenotypic variability in fatal familial insomnia (D178N-129M) genotype.

OBJECTIVE: To report the clinical and pathologic features of patients with the D178N-129M mutation living in Germany. METHODS: Patients with clinically suspected Creutzfeldt-Jakob disease (CJD) were seen in an ongoing, prospective epidemiologic study from June 1993 to August 1997 throughout Germany. Suspect patients were referred to the CJD unit by the participating hospitals or physicians. Patients were seen by a physician, and each patient underwent a detailed neurologic examination. Prion protein gene (PRNP) analysis was performed to distinguish patients with familial forms of CJD. RESULTS: The constellation D178N-129M was identified in eight individuals; in one patient, the diagnosis was made by neuropathologic examination. Four affected men and five women belong to eight unrelated families. A family history of a neurodegenerative disorder was recalled in only five patients. In contrast to the first reported fatal familial insomnia (FFI) patient, none of our patients complained of severe, untreatable insomnia in the early stages. Dysautonomia was observed in varying degrees in most patients. The clinical course of these patients resembled sporadic CJD. In six patients, brain tissue was available for neuropathologic study. In one patient, the neuropathologic examination showed changes that were more reminiscent of forms of sporadic CJD; in the remaining five, the histopathology was typical of FFI. CONCLUSIONS: The clinical presentation in patients with FFI may vary to a great extent. Genotyping of the patients was crucial in providing laboratory confirmation of the diagnosis of FFI, even when there was no family history of a prion disease.

Adult↗
PubMed1997

[The Creutzfeld-Jakob disease. A sphinx of current neurobiology].

BACKGROUND: Prospective epidemiological studies are being employed to determine the incidence and possible risk factors of Creutzfeldt-Jakob disease (CJD) in five European countries in which bovine spongiform encephalopathy (BSE) occurs at different rates of incidence. PATIENTS AND METHODS: Using a voluntary reporting system throughout the Federal Republic of Germany, suspected cases of CJD were investigated and the incidence calculated. Possible risk factors in patients and control groups were obtained by questionnaire. Serum and cerebrospinal fluid samples served to delineate genetic forms and distinguish the disease from other major dementias. RESULTS: A total of 544 patients with suspected CJD, reported in Germany between 1993 and 1997, were examined. 232 (plus 27 investigated only neuropathologically) were confirmed as definite or probable, an annual incidence per million population of between 0.76 (for 1994) and 0.98 (for 1995), similar to figures from other European countries. In Great Britain, the cases of "new variant" CJD, not yet observed in Germany, were excluded from the calculation of incidence. So far, dementia in the family and handling of horn shavings have been identified as risk factors. A rise in the concentrations of neurone-specific enolase and of S100 protein as well as the demonstration of certain proteins in cerebrospinal fluid (p130/ 131 and 14-3-3, respectively) have been shown as being diagnostically superior to EEG changes. INTERPRETATION: There has so far been no increase in the incidence of CJD within Europe. However, the occurrence of the new variant in Great Britain requires long-term monitoring. The diagnostic criteria used for this can be improved by biochemical methods.

Animals↗
PubMed1997

Elevated levels of tau-protein in cerebrospinal fluid of patients with Creutzfeldt-Jakob disease.

Creutzfeldt-Jakob disease (CJD) is a rare, fatal, neurodegenerative disease caused by a transmissible agent designated as proteinaceous infectious agent (prion). Searching for biochemical markers of CJD, we analysed cerebrospinal fluid (CSF) samples of 53 patients for tau-protein using an enzyme linked immunoassay (ELISA). In a group of 21 patients with definite CJD seen in the German case control study for CJD, tau-protein concentrations in CSF were significantly higher than in two control-groups of patients with other diseases (median 13,153 pg/ml, range 1,533-27,648 pg/ml; P = 0.0001). One group comprised 19 patients who were seen in the same study and were diagnosed as having other dementing diseases (tau concentration: median 558 pg/ml, range 233-1,769 pg/ml). The second control group comprised 13 patients from our hospital with no dementing disease (tau concentration: median 296 pg/ml, range 109-640 pg/ml). We conclude that determination of tau protein levels in CSF is a useful marker for laboratory diagnosis of CJD.

Aged↗
PubMed1997

Genetic predisposition to multiple sclerosis as revealed by immunoprinting.

This study was designed to examine the immunogenetic background predisposing to multiple sclerosis (MS). Three hundred fifty-eight clinically well-characterized MS patients from Germany were investigated and compared to 395 healthy control subjects. Each individual was genotyped for 22 polymorphic markers located within or close to immunorelevant candidate genes including HLA-DRB1*, T-cell receptor (TCR), cell interaction molecules, cytokines, and cytokine receptor genes. Altogether, approximately 17,000 genetic analyses were performed. Patients were grouped according to the course of MS-relapsing-remitting or chronic progressive. Most of the genetic markers were not associated with increased risk or their exact contribution was not clear (e.g., tumor necrosis factor). The relative risks for HLA-DRB1*15+ and DRB1*03+ individuals were 3.64 and 1.42, respectively. In both groups of patients, certain TCRB gene polymorphisms were risk factors. In DRB1*03+ individuals the relative risk was increased (> 22) when a specific TCRBV6S3 allele was also inherited. Furthermore, distinct linkage disequilibria of TCRBV6S1/TCRBV6S3 elements in patients and control subjects strongly suggested an additional risk factor in the TCRBV region for DRB1*15+ individuals. These findings are discussed with respect to the pathogenesis and rational approaches to the therapy of MS.

Adolescent↗
PubMed1997

[Expanded illness spectrum of human spongiform encephalopathies or prion diseases].

Since its first description by H.G. Creutzfeldt and A. Jakob, six forms of human spongiform encephalopathies have been described. Besides Creutzfeldt-Jakob disease (CJD), a new variant CJD (nvCJD), Gerstmann-Sträussler-Scheinker syndrome (GSS), fatal familial insomnia (FFI) and potentially familial progressive subcortical gliosis have been reported. The most likely causative agent of these and at least six animal-transmissible spongiform encephalopathies (TSE) is a structurally altered form of a regular cellular protein, designated prion. The best known animal forms are bovine spongiform encephalopathy (BSE) and scrapie. The clinical spectrum of human spongiform encephalopathies has been expanded in recent years by the discovery of new, partially genetically determined forms. The currently available clinical, neurophysiological, neuroradiological, biochemical and molecular-biological methods permit only a probable diagnosis of CJD. A definite diagnosis can only be achieved by the neuropathological demonstration of the pathological prion protein (PrPSc). The transmission of BSE to humans has neither been shown nor definitely excluded.

Animals↗