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C Zimmermann

Publications and source records attributed to C Zimmermann.

At least 55 records · Page 3Linked to original sources
PubMed1999

Increased intracellular calpain detection in experimental focal cerebral ischemia.

Calpains are intracellular proteinases whose proteolytic activity is directed mainly against the cytoskeleton and regulatory proteins. We studied the presence of calpain by immunohistochemistry in a rat model of reversible focal cerebral ischemia (3 h) at various times of reperfusion. The numbers of calpain-positive cells on the ischemic side were compared with the non-ischemic side. In controls only 2 +/- 1% cells were positive, whereas the cortex of the ischemic vs the non-ischemic side showed 88 +/- 3% vs 13 +/- 4% calpain-positive cells (p < 0.001), and the basal ganglia 47 +/- 3% vs 13 +/- 4% (p < 0.01) after 3 h ischemia and 24 h reperfusion. This is the first demonstration of elevated intracellular levels of calpains in areas of cerebral ischemia. Longer reperfusion resulted in an increase in calpain positivity.

Animals↗
PubMed1999

Kinetics of the response of naive and memory CD8 T cells to antigen: similarities and differences.

We have studied the kinetics of the antigen induced response of naive and memory CD8 T cells expressing a transgenic T cell receptor (TCR) specific for the glycoprotein peptide amino acid 33-41 (GP33) of the lymphocytic choriomeningitis virus (LCMV). Memory T cells were generated in vivo by adoptive transfer of LCMV TCR transgenic T cells into normal recipient mice, followed by LCMV infection. The results demonstrated that the cell cycle progression and kinetics of TCR down-modulation, CD25 and CD69 up-regulation were identical in naive and memory T cells after antigen recognition. Moreover, the two T cell populations did not differ in respect of activation thresholds and in their proliferative capacities neither in vitro nor in vivo. However, memory CD8 T cells could be more rapidly induced to become cytolytic and to secrete high levels of interleukin-2 and interferon-gamma than naive T cells. LCMV GP33-specific CD8 memory T cells were only slightly more efficient in reducing LCMV titers in the spleen but were far more effective than naive LCMV GP33-specific T cells in controlling subcutaneous tumor growth of B16.F10 melanoma cells which expressed the LCMV GP33 epitope as tumor-associated antigen. Thus, in our experiments the main difference between CD8 memory T cells and naive cells is the ability of the former to rapidly acquire effector cell functions.

Adoptive Transfer↗
PubMed1999

['Fatigue' in multiple sclerosis].

Fatigue is a common symptom in patients with multiple sclerosis. Rapid exhaustion and reduced exercise tolerance leads to difficulties in maintaining a normal daily life for many patients. Regular resting and short breaks can help to compensate this to a certain degree. The pathophysiology of fatigue is currently unknown. Damage of specific neuroanatomic regions or a more generalized effect of inflammatory mediators in the central nervous system could be the causes of fatigue. Some drugs (e.g. amantadine) have proven effective in therapy of fatigue. Recent therapeutic approaches have begun using aminopyridines (4-aminopyridine, 3,4-diaminopyridine). These two substances are thought to improve nerve conduction, but there might be a central stimulatory effect as well. Overdosage leads to an elevated risk of epileptic seizures and confusion.

Amantadine↗
PubMed1999

[Interferon beta-1b for treatment of secondary chronic progressive multiple sclerosis].

Several phase III studies have proven that the beta-interferons have positive effects on the number and severity of acute exacerbations of relapsing remitting multiple sclerosis. Recently the first study on the effectiveness of interferon beta-1b in secondary progressive multiple sclerosis was published. In a multicenter, double-blind, randomized, Placebo-controlled study 718 patients with secondary progressive multiple sclerosis and an expanded disability status scale (EDSS) value between 3.0 and 6.5 were treated with either 8 Mio.interferon beta-1b or Placebo subcutaneously every second day for two to three years. The primary study end-point was the time until confirmed progression of the disease as signified by a one point increase of the EDSS value (for initial EDSS values between 3.0 and 5.5) or 0.5 point increase when the initial EDSS value was between 6.0 and 6.5. After two years an interim analysis showed a highly significant difference in delay of disease progression by nine to twelve months for the treatment group (p = 0.0008). This means that interferon beta-1b is the first recombinant beta-interferon to be shown effective in the treatment of secondary progressive multiple sclerosis.

Adjuvants, Immunologic↗
PubMed1999

Internet use in radiology: results of a nationwide survey.

PURPOSE: To determine the number of radiologists who currently have Internet access, their use patterns on the Internet for Radiology purposes, the web sites they would recommend, and the potential site access to the Internet that they would like to see in the future. In addition, this study analyzed the best way to find nationwide radiological sites and their content. MATERIALS AND METHODS: In a nationwide survey, 854 Austrian radiologist were asked to fill out and return a questionnaire about Internet access, current problems, current and future use, which web site they recommend, and about the use of e-mail. Next, the available nationwide radiological sites were searched with seven major search engines using 37 different keywords, as well as by category search, and by searching for links on the homepages of the radiological departments of all Universities of Austria. Then, the offered information of the founded pages was classified in categories. RESULTS: Of the 210 (24.6%) radiologists who returned the questionnaire, 154 (73%) had Internet access. Time expenditure was considered the main problem using the Internet. The Internet was used for literature research by 69% of the radiologists with Internet access, for e-mail by 60%, and for congress information by 57%. In future, 43% would like to read electronic journals more often and 39% would like to use the web more intensively for scientific congresses. At the present time, we found 17 radiological web sites in Austria. The most promising way to find these sites was to use the search engines Alta Vista and Hotbot. Fifteen (88%) sites offered information for patients, seven (41%) for radiologists, five (29%) for students, and four (24%) for researchers. SUMMARY: Many radiologists in Austria already have Internet access, although time expenditure was considered the main problem with Internet use. Survey responses showed a need for electronic journals. To our point of view, Universities and radiological societies are urged to publish journals electronically on the Web. Alta Vista and Hotbot were the best search engines for radiological sites in our setting, and a careful reading of the specific search engine's instructions is recommended. In our experience, Web pages with clear structure, small file size, precise HTML keyword editing, and page titles, facilitate more accurate discovery of specific sites. In addition, there seems to be a need for regular publication of reviewed radiological link collections and the establishment of standards for teleconsulting.

Austria↗
PubMed1998

Tumor-infiltrating lymphocytes exhibiting high ex vivo cytolytic activity fail to prevent murine melanoma tumor growth in vivo.

The identification of tumor-associated Ags recognized by CD8+ CTL and prevention of tumor outgrowth by adoptive transfer of these CTL demonstrates that CD8+ T cells play a major role in antitumor immunity. We have generated B16.F10 melanoma cells that express the glycoprotein epitope amino acid 33-41 (GP33) of the lymphocytic choriomeningitis virus (LCMV) to examine antitumor CD8+ T cell response in C57BL/6 mice immune to LCMV and in mice transgenic for the LCMV GP33-specific P14 TCR (P14 TCR mice). We find that B16.F10GP33 tumor cells grew in syngeneic C57BL/6 mice without inducing T cell tolerance. LCMV infection or adoptive transfer of LCMV-specific effector T cells delayed but did not prevent growth of preestablished tumors in these mice. However, B16.F10GP33 tumor cells were rejected in mice immune to LCMV and in mice treated with LCMV-specific effector T cells on the same day as the tumor. Surprisingly, B16.F10GP33 tumor cells grew in P14 TCR transgenic mice despite an abundance of tumor-associated Ag-specific CD8+ T cells. In these mice, freshly isolated tumor-infiltrating lymphocytes exhibited an activated phenotype and displayed high GP33-specific cytolytic activity when assessed ex vivo. Thus, B16.F10GP33 melanoma cells are able to initiate, but not to sustain, a GP33-specific CTL response sufficient to clear the tumor enduringly.

Adoptive Transfer↗
PubMed1998

SV40 T/t-antigen induces premature mammary gland involution by apoptosis and selects for p53 missense mutation in mammary tumors.

We recently established transgenic animals (WAP-SV-T/t) carrying the early coding region of Simian Virus 40 (SV40) under the transcriptional control of the whey acidic milk protein promoter (WAP), which restricts the expression of the transgene to mammary gland epithelial cells (ME-cells). SV40 T/t-antigen synthesis causes premature mammary gland involution during late pregnancy by inducing apoptosis and leads to development of mammary tumors after the first lactation period in both p53 positive (WAP-SV-T/t) and p53 negative double transgenic animals (WAP-SV-T/t.p53-/-). The high apoptotic rate persists in all of the T/t-antigen positive breast tumor cells, as well as in established ME-tissue culture cell lines. ME-cells which spontaneously switch off the expression of the WAP-SV-T/t transgene do not undergo apoptosis. However, these cells again exhibit an extensive DNA fragmentation when SV40 T/t-antigen synthesis is reintroduced, which indicates that it is the expression of T/t antigen which is the critical factor for induction of apoptosis. In addition, we isolated several ME-cell lines from different breast tumors which have spontaneously lost the T/t-antigen yet remain maximally transformed. Strikingly, these cells contain a missense mutation of the p53 gene at codon 242 (p53(242)), which substitutes alanine for glycine. This mutation increases p53 stability and it reduces the transactivating function of p53, albeit without affecting the ability of the protein to interact with the DNA. This indicates that p53 missense mutations are selected for in breast tumors initially expressing T/t-antigen. Therefore, the p53(242) mutation is sufficient to maintain the transformed state after the ME-cells have switched off the WAP-SV-T/t transgene. Interestingly, the p53 minus state per se is not sufficient to induce ME-cell transformation since homozygous null mice for the p53 gene (p53-/-) fail to develop breast cancer.

Animals↗
PubMed1998

Induction of protective cytotoxic T cell responses in the presence of high titers of virus-neutralizing antibodies: implications for passive and active immunization.

The effect of preexistent virus-neutralizing antibodies on the active induction of antiviral T cell responses was studied in two model infections in mice. Against the noncytopathic lymphocytic choriomeningitis virus (LCMV), pretreatment with neutralizing antibodies conferred immediate protection against systemic virus spread and controlled the virus below detectable levels. However, presence of protective antibody serum titers did not impair induction of antiviral cytotoxic T lymphocyte (CTL) responses after infection with 10(2) PFU of LCMV. These CTLs efficiently protected mice independent of antibodies against challenge with LCMV-glycoprotein recombinant vaccinia virus; they also protected against otherwise lethal lymphocytic choriomeningitis caused by intracerebral challenge with LCMV-WE, whereas transfused antibodies alone did not protect, and in some cases even enhanced, lethal lymphocytic choriomeningitis. Against the cytopathic vesicular stomatitis virus (VSV), specific CTLs and Th cells were induced in the presence of high titers of VSV-neutralizing antibodies after infection with 10(6) PFU of VSV, but not at lower virus doses. Taken together, preexistent protective antibody titers controlled infection but did not impair induction of protective T cell immunity. This is particularly relevant for noncytopathic virus infections since both virus-neutralizing antibodies and CTLs are essential for continuous virus control. Therefore, to vaccinate against such viruses parallel or sequential passive and active immunization may be a suitable vaccination strategy to combine advantages of both virus-neutralizing antibodies and CTLs.

Animals↗
PubMed1998

Beta-galactoside-binding protein secreted by activated T cells inhibits antigen-induced proliferation of T cells.

We have used mRNA differential display PCR to search for genes induced in activated T cells and have found the LGALS1 (lectin, galactoside-binding, soluble) gene to be strongly up-regulated in effector T cells. The protein coded by the LGALS1 gene is a beta-galactoside-binding protein (betaGBP), which is released by cells as a monomeric negative growth factor but which can also associate into homodimers (galectin-1) with lectin properties. Northern blot analysis revealed that ex vivo isolated CD8+ effector T cells induced by a viral infection expressed high amounts of LGALS1 mRNA, whereas LGALS1 expression was almost absent in resting CD8+ T cells. LGALS1 expression could be induced in CD4+ and CD8+ T cells upon activation with the cognate peptide antigen and high levels of LGALS1 expression were found in concanavalin A-activated T cells but not in lipopolysaccharide-activated B cells. Gel filtration and Western blot analysis revealed that only monomeric betaGBP was released by activated CD8+ T cells and in vitro experiments further showed that recombinant betaGBP was able to inhibit antigen-induced proliferation of naive and antigen-experienced CD8+ T cells. Thus, these data indicate a role of betaGBP as an autocrine negative growth factor for CD8+ T cells.

Animals↗
PubMed1998

The concurrence of rheumatoid arthritis and limited systemic sclerosis: clinical and serologic characteristics of an overlap syndrome.

OBJECTIVE: The characteristics of 3 patients with longstanding rheumatoid arthritis (RA) and consecutive evolution of limited cutaneous systemic sclerosis (IcSSc) were evaluated and compared with those of patients with IcSSc alone (n = 20) or with RA alone (n = 120). METHODS: Clinical features of the different patient populations were compared. Serologic analyses included tests for antinuclear antibodies (ANA) and ANA subsets, in particular anticentromere antibodies (ACA) and anti-heterogeneous nuclear RNP (hnRNP)-A2/RA33 (anti-A2/RA33). RESULTS: The 3 patients with RA developed IcSSc 11, 29, or 50 years after the onset of RA. Features of IcSSc were Raynaud's phenomenon, sclerodactyly, and telangiactasias in all 3 patients, and esophageal dysmotility in 1 patient. Rheumatoid factor (RF) and anti-A2/ RA33 were each found in 2 patients, and 1 of these patients was seropositive for both RF and anti-A2/RA33. ACA titers were positive in all cases. However, similar to the development of RA prior to IcSSc, the occurrence of autoantibodies typical of RA preceded the occurrence of ACA, at least in 2 of the patients. Using affinity-purified antibodies, cross-reactivities between anti-centromere protein A (CENP-A) and anti-CENP-B antibodies with anti-A2/RA33 antigens were seen in the 2 anti-A2/RA33-positive patients. Such cross-reactivities were not found in IcSSc patients without concomitant RA. Epitope mapping revealed that both autoantibody specificities recognized the known major epitopes: anti-CENP-B reacted with the C-terminal region and anti-A2/RA33 with the second RNA binding domain in the N-terminal region of hnRNP-A2. CONCLUSION: The RA-lcSSc overlap syndrome in these 3 patients with longstanding RA was characterized by an incomplete CREST (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasias) syndrome. The study demonstrated the presence of autoantibodies typical of both diseases and cross-reactivity of ACA with hnRNP-A2/RA33 in the sera of these patients.

Adult↗
PubMed1998

Which patients talk about stressful life events and social problems to the general practitioner?

BACKGROUND: Life events and social problems are common in primary-care attenders and contribute to the high rate of emotional distress observed in this setting but are often not disclosed during the consultation. Physicians' characteristics associated with patients' disclosure of psychosocial problems are well documented, but less empirical evidence is available on the contribution of patients' variables. METHOD: Logistic regression analyses were performed on a set of clinical and psychosocial data from 319 primary-care attenders with stressful life events and/or social problems in the presence or absence of emotional distress, in order to identify the variables that predict disclosure of such problems during the consultation. RESULTS: Two-thirds of patients with stressful life events and social problems had mentioned them to their GP. In both sexes a positive attitude about confiding and emotional distress were the best predictors of confiding. In men they accounted for 76% of correct predictions and, in women, together with past confiding, long-lasting relationship with GP, and coexistence of life events and social problems, for 81%. A positive confiding attitude was related in males to age and severity of medical condition and in females to age and experience of past confiding. CONCLUSIONS: In view of the high prevalence of positive attitude towards confiding the efforts by GPs should focus on the reduction of disclosure thresholds. This would require increased abilities to elicit psychosocial information and show emphatic understanding of patients' life difficulties. By contrast there is a need to promote a positive attitude in confiding that concerns only a minority of primary-care patients. More data are needed for shaping more specific strategies for these patients.

Adult↗
PubMed1998

[Fetal supraventricular tachycardia associated with anasarca: poor prognosis despite treatment. Apropos of two cases].

Two cases of foetal supraventricular tachycardia with hydrops with fatal outcomes illustrate the poor general prognosis of this condition. The absence of therapeutic consensus, of large series in the existing literature, does not prevent logical and reasonable management based on rhythmological, pharmacological and prognostic criteria. A combined approach associating antiarrhythmic therapy by the transplacental and intrafunicular approaches seems acceptable now that funicular puncture can be undertaken easily, and certain antiarrhythmic molecules suggest encouraging results. It is important to try to assess the haemodynamic tolerance by foetal Doppler echocardiography because the foetal prognosis depends on ischaemic cerebral lesions induced by anoxia, difficult to diagnose in utero: when observed, aggressive and occasionally dangerous therapies to foetus and mother may be justified in these extreme situations of foetoplacental hydrops.

Adult↗
PubMed1997

Elevated serum concentrations of soluble adhesion molecules in coronary artery disease and acute myocardial infarction.

OBJECTIVES: Adhesion molecules are involved in a number of chronic conditions and diseases like rheumatoid arthritis, tumor growth and wound repair. Soluble adhesion molecules (SAM) play an important role in angiogenesis which is a common aspect of the conditions mentioned above and atherosclerosis. The aim of the present study was to assess the prevalence and the impact of elevated soluble adhesive molecule plasma concentrations in patients with atherosclerosis. DESIGN AND SUBJECTS: In this study, we measured the soluble forms of intercellular adhesive molecule (sICAM), endothelial adhesive molecule (sELAM) and vascular adhesive molecule (sVCAM) using a sandwich ELISA technique in plasma of patients with acute myocardial infarction (AMI), coronary heart disease (CHD) and in healthy subjects (HS). RESULTS: Patients suffering from CHD and AMI showed significant higher plasma concentrations of sICAM (p <0. 05 and p <0.005), sELAM (p <0.01 and p <0.001) and sVCAM (p <0.001 and p <0.005) than HS. In patients with fatal outcome of myocardial infarction the plasma concentrations of sICAM, sELAM and sVCAM were significantly elevated compared to surviving patients (p <0.005; p <0.005; p <0.05). In patients undergoing thrombolytic therapy there were no significant differences of plasma adhesive molecule concentrations. The levels of SAM were not related to other risk factors like diabetes, nicotin abuse, hyperlipidemia, hypertension and a familiary history of cardiovascular disease. CONCLUSIONS: Elevated levels of SAMs are found in patients with coronary heart disease. High SAM levels in plasma seem to be a prognostic factor in acute myocardial infarction. This effect is independent from other concomitant risk factors. Our results suggest that SAMs are involved both in acute phase of myocardial infarction and chronic process of atherosclerosis. It seems that similiar to other chronic inflammatory diseases, atherosclerosis seems to be modulated by soluble forms of adhesive molecules.

Adult↗
PubMed1997

Metastatic melanoma of unknown primary origin shows prognostic similarities to regional metastatic melanoma: recommendations for initial staging examinations.

BACKGROUND: Metastatic melanoma of unknown primary origin accounts for approximately 2-6% of all melanoma cases. The prognostic significance of this diagnosis is still controversial. METHODS: Of 3258 patients with malignant melanoma recorded during the period 1976-1996, 2.3% had metastases of unknown primary origin. Anatomic distribution, clinical stage, and survival probabilities were evaluated. RESULTS: Thirty patients were classified as having cutaneous or subcutaneous in-transit metastases, and they showed a 5-year survival rate of 83%. Thirty-seven patients were classified as having lymph node metastasis, and their 5-year survival rate was 50%. Disseminated disease was diagnosed in only 8 patients, who had a median survival of 6 months. Comparison of survival probabilities for patients with in-transit metastases and unknown primary tumors with the probabilities for those with cutaneous primary tumors revealed a significant advantage for the former group. No significant differences were found for patients with lymph node metastasis when those with unknown primary tumors were compared with those who had cutaneous melanomas with regional lymph node metastasis. CONCLUSIONS: The clinical disease course of patients with metastatic melanoma of unknown primary origin is similar to that of patients with primary cutaneous melanoma when the same clinical stages of the disease are compared. Based on the assumption that the majority of regional metastases develop from completely regressed primary cutaneous melanoma, recommendations for initial staging examinations in patients with unknown primary tumors are given in this article.

Adolescent↗
PubMed1997

[Not Available].

Explore the source record for details and available documents.

Journal Article↗
PubMed1997

Antiviral immune responses in CTLA4 transgenic mice.

The role of B7 binding CD28 in the regulation of T- and B-cell responses against viral antigens was assessed in transgenic mice expressing soluble CTLA4-Hgamma1 (CTLA4-Ig tg mice) that blocks B7-CD28 interactions. The results indicate that transgenic soluble CTLA4 does not significantly alter cytotoxic T-cell responses against replicating lymphocytic choriomeningitis virus (LCMV) or vaccinia virus but drastically impairs the induction of cytotoxic T-cell responses against abortively replicating vesicular stomatitis virus (VSV). While the T-independent neutralizing immunoglobulin M (IgM) responses were within normal ranges, the switch to IgG was reduced 4- to 16-fold after immunization with abortively replicating VSV and more than 30-fold after immunization with an inert VSV glycoprotein antigen in transgenic mice. IgG antibody responses to LCMV, as detected by enzyme-linked immunosorbent assay and by neutralizing action, were reduced about 3- to 20-fold and more than 50-fold, respectively. These results suggest that responses in CTLA4-Ig tg mice are mounted according to their independence of T help. While immune responses to nonreplicating or poorly replicating antigens are in general most dependent on T help and B7-CD28 interactions, they are most impaired in CTLA4-Ig tg mice. The results of the present experiments also indicate that highly replicating viruses, because of greater quantities of available antigens and by inducing as-yet-undefined factors and/or cell surface changes, are capable of compensating for the decrease in T help caused by the blocking effects of soluble CTLA4.

Abatacept↗
PubMed1997

Mouse DNA methyltransferase (MTase) deletion mutants that retain the catalytic domain display neither de novo nor maintenance methylation activity in vivo.

The mammalian genome encodes a DNA cytosine-5-methyltransferase (MTase) of about 170 kDa that is apparently responsible for both de novo and maintenance methylation at CpG sites. Both methylation activities have to be regulated accurately to ensure correct developmental and cell type-specific gene activity. Distorted DNA methylation patterns have been associated with cell aging and diseases such as cancer and fragile X syndrome. Structural and functional in vitro studies of the mouse MTase have indicated that the enzyme has both a regulatory and a catalytic region located in the N-terminal and C-terminal parts of the protein, respectively. The regulatory region includes the nuclear localization signal (NLS), the sequence for DNA targeting and the Zn-binding domain. The catalytic domain carries the ten consensus sequence motifs specific for all known pro- and eukaryotic DNA cytosine-5-methyltransferases. In an attempt to separate regulatory and catalytic functions of the enzyme in vivo, we have tested various deletion mutations by means of transient and stable cell transfection experiments. Expression of the transgenes, all of which retained the C-terminal catalytic domain, was monitored by immunofluorescence staining, Northern blot analysis and SDS gel electrophoresis. Despite high levels of transgene expression, the truncated MTase molecules exhibited neither de novo nor maintenance methylation activity. These findings might indicate that in vivo, an efficient control mechanism prevents the ectopic activity of the DNA MTase that is structurally compromised in its N-terminal regulatory region.

Animals↗