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Biomedical subjects

N Fischer

Publications and source records attributed to N Fischer.

At least 19 recordsLinked to original sources
PubMed2005

Is perceived social support a predictor of survival for patients undergoing autologous peripheral blood stem cell transplantation?

PURPOSE: Previous research discussed the predictive value of psychosocial variables along with biomedical predictors for survival; such as affective functioning and quality of life. The present study addresses the following research question: does perceived social support prior to PSBCT have an impact on post-transplant survival? SUBJECTS AND METHODS: Ninety-nine patients suffering from Multiple Myeloma (n=55), Non-Hodgkin Lymphoma (n=33), and other malignancies (n=11) completed the Illness Specific Scales of Social Support (ISSS) before undergoing PBSCT. ISSS is comprised of the subscales 'positive social support' and 'problematic social support', e.g. criticising, victimising, or avoiding interactions. RESULTS: The mean score in the subscale 'positive social support' was 3.2 (S.D. 0.54; range 0 until 4), in the subscale 'negative social support' 0.94 (S.D. 0.53). There was no association between positive interactions and survival following PBSCT. Conversely, those patients perceiving problematic social support, showed a correspondence with poor survival following PBSCT (RR=3.649; p=0.015; Cox-regression analysis). The following variables were controlled: Karnofsky Performance Status, interferon treatment, depression and participation in psychotherapy. CONCLUSION: Differentiating between positive and problematic interactions prior to PBSCT helps to recognise detrimental forms of social support. Future research should investigate the clinical implications and help tailor psychotherapeutic intervention.

Adult↗
PubMed2004

Individual quality of life of patients undergoing autologous peripheral blood stem cell transplantation.

BACKGROUND: Most quality-of-life (QoL) studies in autologous Peripheral Blood Stem Cell Transplantation (PBSCT) are descriptive and concentrate on symptom severity and functional deficits. The aim of this study is to compare individual QoL (iQoL) with health-related QoL (hrQoL) and functional status of patients before high-dosed therapy/PBSCT. PATIENTS AND METHODS: Multiple Myeloma, non-Hodgkin's Lymphoma and other tumor patients were asked to complete the following measures before high-dosed therapy/PBSCT: the European Organization for Research and Treatment of Cancer (EORTC) Quality-of-life Questionnaire Core 30 (QLQ-C30), and the Schedule for the Evaluation of Individual QoL-Direct Weighting (SEIQoL-DW), a patient-generated instrument which allows the patients to nominate the five most important domains (cues) for their present QoL. The SEIQoL-DW assessment generates: (1) a global QoL score (SEIQoL-INDEX), calculated as Sigma(levelsxweights); (2) the current overall QoL, rated on a visual analogue scale (VAS). Additional measures included demographic data, clinical disease status of remission and Karnofsky's index. RESULTS: Seventy-nine patients completed both types of questionnaires. The QoL domains nominated by the patients were assigned to groups (aggregated cues), the most frequent of which were family (89%), hobbies/pastimes (74%), health (physical, including mobility) (70%), profession/occupation (51%), social life/friends (47%) and marriage/partnership (33%). There was no correlation between the SEIQoL-DW total scores and the EORTC QLQ-C30 scale or the Karnofsky index. CONCLUSION: Individual QoL as assessed by the SEIQoL-DW is unrelated to standard health-status measures such as the EORTC QLQ-C30 or the Karnofsky index. Patient-perceived iQoL in PBSCT seems to depend largely on areas others than health and physical functioning, with the family playing a prominent role.

Activities of Daily Living↗
PubMed2002

Chlamydia trachomatis infection in cervical intraepithelial neoplasia and invasive carcinoma.

We analyzed 149 women (81 with cervical intraepithelial neoplasia and with invasive carcinoma of the cervix and 68--as a control group). The influence of Chlamydia trachomatis (Cht) infection into expression of EGFR, TGF-alpha, Ki 67, HPV 16 and 18 was examined. IS-PCR was used to measure the level of antibodies in the serum. We detected that chlamydial infection may cause cervical hypertrophy in women with and without cervical intraepithelial neoplasia and invasive carcinoma. Infections of both Cht and HPV correlate with high expession of Ki 67 in epithelium. Cht infection also increased the expression of HPV16 in CIN I. These results suggest that Cht infection modifies the activity of viruses. In our research we have confimed that Cht infection increases the expression of EGFR and TGF-alpha. These facts may explain variants other than the HPV-mechanism of cervical carcinogenesis.

Adult↗
PubMed2002

Chlamydia trachomatis infection in women with CIN and invasive uterine cervix cancer. Significance of hormonal status.

In women with CIN at fertile age and those over 50 years of age, EGFR expression is lower in the presence of Chlamydia trachomatis (Cht) infection. In all Cht infected women over 50 years of age expression of Ki 67 is higher; the increase is significant among women with invasive carcinoma. In these groups of women with CIN and invasive carcinoma TGF-alpha expression is insignificantly augmented. Chronic Cht infection is associated with cervical hypertrophy.

Adult↗
PubMed2001

Expression of the anti-dorsalizing morphogenetic protein gene in the zebrafish embryo.

The BMP3 related anti-dorsalizing morphogenetic protein (ADMP) has been proposed to function in the organizer of chick and Xenopus embryos. We report here the cloning and expression pattern of a zebrafish admp gene. The gene is expressed in involuting cells of the embryonic shield, but not in the non-involuting forerunner cells. During gastrulation, admp transcripts are detected in the posterior prechordal plate, in the notochord primordium and in cells of the dorsal blastoderm margin. Expression is also detectable in the neuroectoderm overlying the posterior prechordal plate. Expression persists in the tail bud until the end of somitogenesis while expression in other areas disappears during early somitogenesis stages.

Amino Acid Sequence↗
PubMed2001

A crucial component of the endoderm formation pathway, CASANOVA, is encoded by a novel sox-related gene.

casanova (cas) mutant zebrafish embryos lack endoderm and develop cardia bifida. In a substractive screen for Nodal-responsive genes, we isolated an HMG box-containing gene, 10J3, which is expressed in the endoderm. The cas phenotype is rescued by overexpression of 10J3 and can be mimicked by 10J3-directed morpholinos. Furthermore, we identified a mutation within 10J3 coding sequence that cosegregates with the cas phenotype, clearly demonstrating that cas is encoded by 10J3. Epistasis experiments are consistent with an instructive role for cas in endoderm formation downstream of Nodal signals and upstream of sox17. In the absence of cas activity, endoderm progenitors differentiate into mesodermal derivatives. Thus, cas is an HMG box-containing gene involved in the fate decision between endoderm and mesoderm that acts downstream of Nodal signals.

Amino Acid Sequence↗
PubMed2001

Identification of nodal signaling targets by array analysis of induced complex probes.

Nodal signaling controls germ layer formation, left-right asymmetry, and patterning of the brain in the vertebrate embryo. Cellular responses to Nodal signals are complex and include changes in gene expression, cell morphology, and migratory behavior. Only little is known about the genes regulated by Nodal signaling. We designed a subtractive screening strategy by using a constitutively active Nodal receptor to identify putative target genes of Nodal signals in the early gastrula of zebrafish embryos. By quantitative analysis of macro-array hybridizations, 132 genes corresponding to 1.4% of genes on the entire macro-array were identified, which were enriched in the Nodal-induced probe pool. These genes encode components of signal transduction pathways, transcription regulators, proteins involved in protein metabolism but also cytoskeletal components and metabolic enzymes, suggesting dramatic changes of cell physiology in gastrula cells in response to Nodal signals.

Animals↗
PubMed2001

The flanking regions of PsaD drive efficient gene expression in the nucleus of the green alga Chlamydomonas reinhardtii.

The nuclear gene PsaD encodes an abundant chloroplast protein located on the stromal side of the Photosystem I complex. We have cloned and sequenced a genomic fragment containing the PsaD gene from the green alga Chlamydomonas reinhardtii. Sequence comparison with its cDNA revealed that the PsaD ORF contains no introns. Thus, the regulatory sequences required for high-level expression of PsaD must lie in the flanking promoter and untranslated regions. We used this genomic fragment to construct a vector that allows for high-level expression of endogenous and exogenous genes, as well as cDNAs that could not be expressed from existing vectors. It is also possible to use the PsaD transit sequence to target the expressed protein to the chloroplast compartment.

Animals↗
PubMed2001

Expression of brain subtype creatine kinase in the zebrafish embryo.

Creatine kinases (CK) play crucial roles in intracellular energy transfer. We have isolated a cDNA from zebrafish embryos, which encodes a CK highly related to the mammalian brain subtype creatine kinase (BCK). The bck mRNA is expressed maternally in the zebrafish embryo and transcripts are distributed uniformly in blastula and gastrula stages. Expression becomes restricted to the prechordal plate and the nervous system during subsequent somitogenesis stages. bck transcripts are abundant in primary neurons in the developing central nervous system of the 1-day-old embryo. While some bck expression persists in the hindbrain, expression vanishes in the spinal cord of the 2-day-old embryo. In summary, the expression pattern of bck is highly dynamic and suggests a role for bck during gastrulation and neuronal differentiation.

Amino Acid Sequence↗
PubMed2001

Comparison of replication-competent molecular clones of porcine endogenous retrovirus class A and class B derived from pig and human cells.

Vertically transmitted endogenous retroviruses pose an infectious risk in the course of pig-to-human transplantation of cells, tissues, and organs. Two classes of polytropic type C porcine endogenous retroviruses (PERV) which are infectious for human cells in vitro are known. Recently, we described the cloning and characterization of replication-competent PERV-B sequences from productively infected human cells (F. Czauderna, N. Fischer, K. Boller, R. Kurth, and R. R. Tönjes, J. Virol. 74:4028-4038, 2000). Here, we report the isolation of infectious molecular PERV-A and PERV-B clones from pig cells and compare these proviruses with clones derived from infected human 293 cells. In addition to clone PERV-A(42) derived from 293 cells, four "native" full-length proviral PERV sequences derived from a genomic library of the porcine cell line PK15 were isolated. Three identical class A clones, designated PK15-PERV-A(42), PK15-PERV-A(45), and PK15-PERV-A(58), and one class B clone, PK15-PERV-B(213), were characterized. PK15-PERV-B(213) is highly homologous but distinct from the previously described clone PERV-B(43). PK15-PERV-A(58) demonstrates close homology to PERV-A(42) in env and to PERV-C in long terminal repeat, gag, and pro/pol sequences. All three PERV clones described here were replication competent upon infection of susceptible cell lines. The findings suggest that the pig genome harbors a limited number of infectious PERV-A and -B sequences.

Animals↗
PubMed2001

The number of a U3 repeat box acting as an enhancer in long terminal repeats of polytropic replication-competent porcine endogenous retroviruses dynamically fluctuates during serial virus passages in human cells.

The organization and transcriptional regulation of porcine endogenous retrovirus (PERV) long terminal repeats (LTRs) are unknown. We have studied the activity of LTRs from replication-competent molecular clones by performing luciferase reporter assays. The LTRs differ in the presence and number of 39-bp repeats located in U3 that confer strong promoter activity in human, simian, canine, feline, and porcine cell lines, whereas for LTRs devoid of the repeats, the promoter strength was significantly reduced. As the activity of a heterologous simian virus 40 promoter and a homologous repeat-deficient LTR was elevated by four 39-bp repeats independently of its orientation and location, the repeat box complies with the definition of an enhancer. During serial virus passaging of molecular PERV clones on human 293 cells, proviral LTRs demonstrated adaptation of transcriptional activity by dynamic changes of the number of 39-bp repeats in the course of up to 12 passaging cycles.

Animals↗
PubMed2001

Detection of Chlamydia trachomatis infection in women with CIN and invasive carcinoma. Controversial results of different methods.

Chlamydia (Ch.) trachomatis infection as a sexually transmitted disease is highly important, but reliable methods of diagnosing it remain to be worked out. We used three methods of detection: an immunoenzymatic technique for detection of Ch. trachomatis antigen in endocervical material, in situ PCR, and enzyme-immuno assay for detection of IgG class anti-Ch. trachomatis antibodies in serum. We have compared the IS-PCR technique and method of detection of the endocervical antigen. We have not confirmed compatibility of the results obtained in these two methods. Parallel positive results obtained in patient serum and detection of chlamydial DNA by IS-PCR have been accepted to be indicative of persistent infection of Ch. Trachomatis.

Adult↗
PubMed2000

Ribavirin inhibits West Nile virus replication and cytopathic effect in neural cells.

West Nile virus (WNV) is an emerging mosquito-borne pathogen that was reported for the first time in the Western hemisphere in August 1999, when an encephalitis outbreak in New York City resulted in 62 clinical cases and 7 deaths. WNV, for which no antiviral therapy has been described, was recently recovered from a pool of mosquitoes collected in New York City. In anticipation of the recurrence of WNV during the summer of 2000, an analysis was made of the efficacy of the nucleoside analogue ribavirin, a broad-spectrum antiviral compound with activity against several RNA viruses, for treatment of WNV infection. High doses of ribavirin were found to inhibit WNV replication and cytopathogenicity in human neural cells in vitro.

Antiviral Agents↗
PubMed2000

Spatiotemporal regulation of hnRNP M and 2H9 gene expression during mouse embryonic development.

Using the HeLa cell model along with an in vitro splicing system, we have previously shown that hnRNP M and 2H9 are involved in the pre-mRNA splicing process and most interestingly also in heat shock-induced transient splicing arrest by transiently leaving the hnRNP complexes. Due to this unique regulatory function in a mechanism that turns splicing on and off, these two hnRNPs appear as important proteins for controlling gene expression. Here we investigated by in situ hybridization and immunohistochemical staining techniques the expression level of specific mRNA and protein during mouse embryonic development. HnRNP M and 2H9 are found to be expressed at all examined stages (6.5-18.5 days post-coïtum), in a differential manner, and at various levels depending on tissues, cell types and also embryonic stages; fairly high levels of both hnRNPs are always observed in the central nervous system. Furthermore, levels of colocalizing protein and transcript are not always present in the same proportion, thus suggesting a post-transcriptional regulation of hnRNP M and 2H9 gene expression. The complex spatiotemporal variations we observed might well anticipate a role for these two hnRNPs also in modulating splicing, thereby influencing gene expression and further many physiological processes.

Animals↗
PubMed2000

Generation and testing of a highly specific anti-serum directed against porcine endogenous retrovirus nucleocapsid.

Advances in xenotransplantation offer chances to alleviate the shortage of human donor organs. The discovery that pig endogenous retroviruses (PERV) can infect human cells in vitro has stimulated the discussion on infectious risk in xenotransplantation. A molecular and immunologic monitoring of xenograft recipients and of donor animals for putative infection with PERV and other microorganisms is inevitable. In this report, we describe the generation and testing of a highly specific anti-serum directed against the PERV nucleocapsid protein. The Gag amino acid (aa) sequence of PERV class B was used to define immunogenic domains by computer analysis. A peptide corresponding to the C-terminal 19 aa of the 10 kDa (p10) nucleocapsid (NC) portion of the Gag polyprotein was used to immunize rabbits. The generated serum was tested using recombinant PERV Gag protein expressed in insect cells, purified PERV virus particles and human 293 cells transfected or infected with PERV, respectively. Test methods included Western blotting, indirect immunofluorescence, immunoperoxidase assay and ELISA. The PERV anti-serum provides a tool that is instrumental for detection of a potential agent of zoonosis. It can be used for screening of donor animals and xenograft recipients in the course of xenotransplantation procedures.

Amino Acid Sequence↗
PubMed2000

Establishment and characterization of molecular clones of porcine endogenous retroviruses replicating on human cells.

The use of pig xenografts is being considered to alleviate the shortage of allogeneic organs for transplantation. In addition to the problems overcoming immunological and physiological barriers, the existence of numerous porcine microorganisms poses the risk of initiating a xenozoonosis. Recently, different classes of type C porcine endogenous retoviruses (PERV) which are infectious for human cells in vitro have been partially described. We therefore examined whether completely intact proviruses exist that produce infectious and replication-competent virions. Several proviral PERV sequences were cloned and characterized. One molecular PERV class B clone, PERV-B(43), generated infectious particles after transfection into human 293 cells. A second clone, PERV-B(33), which was highly homologous to PERV-B(43), showed a G-to-A mutation in the first start codon (Met to Ile) of the env gene, preventing this provirus from replicating. However, a genetic recombinant, PERV-B(33)/ATG, carrying a restored env start codon, became infectious and could be serially passaged on 293 cells similar to virus clone PERV-B(43). PERV protein expression was detected 24 to 48 h posttransfection (p. t.) using cross-reacting antiserum, and reverse transcriptase activity was found at 12 to 14 days p.t. The transcriptional start and stop sites as well as the splice donor and splice acceptor sites of PERV mRNA were mapped, yielding a subgenomic env transcript of 3. 1 kb. PERV-B(33) and PERV-B(43) differ in the number of copies of a 39-bp segment in the U3 region of the long terminal repeat. Strategies to identify and to specifically suppress or eliminate those proviruses from the pig genome might help in the production of PERV-free animals.

Animals↗
PubMed2000

Expression and characterization of the Borna disease virus polymerase.

Borna disease virus is the prototype of a new family, Bornaviridae, within the order Mononegavirales, that is characterized by nuclear transcription, splicing, low level replication, and neurotropism. The products of five open reading frames predicted from the genomic sequence have been confirmed; however, expression of the sixth, corresponding to the putative viral polymerase (L), has not been demonstrated. Here, we describe expression and characterization of a 190-kDa protein proposed to represent L. Expression of this protein from the third transcription unit of the viral genome is dependent on a splicing event that fuses a small upstream open reading frame in frame with the larger downstream continuous open reading frame. The protein is detected by serum antibodies from infected rats and is present in the nucleus, where it colocalizes with the phosphoprotein. L is also shown to be phosphorylated by cellular kinases and to interact with the viral phosphoprotein in coimmunoprecipitation studies. These findings are consistent with the identity of the 190-kDa protein as the viral polymerase and provide insights and describe reagents that will be useful for Bornavirus molecular biology and pathobiology.

Amino Acid Sequence↗