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Biomedical subjects

J Nielsen

Publications and source records attributed to J Nielsen.

At least 55 records · Page 3Linked to original sources
PubMed2002

Cytokine mRNA profiles in bronchoalveolar cells of piglets experimentally infected in utero with porcine reproductive and respiratory syndrome virus: association of sustained expression of IFN-gamma and IL-10 after viral clearance.

An experimental model was used to investigate mRNA cytokine profiles in bronchoalvolar cells (BALC) from piglets, infected in utero with porcine reproductive and respiratory syndrome virus (PRRSV). The BALC's were analyzed for the cytokines TNF-alpha, IFN-gamma, IL-8, IL-10, and IL-12(p40) by real-time TaqMan polymerase chain reaction in 2-, 4-, and 6-week-old piglets, respectively. High levels of IFN-gamma mRNA was detected in all piglets, while IL-10 was upregulated in 2-week-old piglets, was at normal levels in 4-week-old piglets, and elevated again in 6-week-old piglets. IL-12 was weakly elevated in all three age groups. Virus was reduced by 50% in 4-week-old piglets and cleared by 6 weeks of age. The sustained expression of IFNgamma and reduction of IL-10 production indicate an important role for these cytokines in immunity to PRRSV.

Animals↗
PubMed2002

A longitudinal study of cell-mediated immunity in pigs infected with porcine parvovirus.

Porcine parvovirus (PPV) is an ubiquitous pathogen causing reproductive failure in swine. Protection against reproductive failure caused by acute PPV infection has commonly been related to the presence of specific antibodies in the dam. However, the role of cell-mediated immunity during chronic PPV infection remains to be elucidated, and may be relevant to the pathogenesis of novel diseases such as postweaning multisystemic wasting syndrome (PMWS), which may be triggered by coinfection with PPV and porcine circovirus type 2 (PCV2). To investigate whether pigs infected with PPV generate a cell-mediated immune response, a longitudinal infection experiment was performed, using swine leukocyte antigens (SLA) class I characterized growing pigs (haplotype H7/H7). Pigs were intranasally inoculated with PPV at 0, 80, and 136 days. At predetermined time points, peripheral blood mononuclear cells (PBMC) were isolated, and virus-specific lymphoproliferative responses and the cytolytic activities of cytotoxic T-lymphocytes (CTL) and natural killer (NK) cells were examined. Cytolytic assays were performed by the chromium release method, using as targets a syngeneic porcine kidney cell line established for the purpose (CTL assays) and K562 cells (NK assays). A specific proliferative response of PBMC from virus-infected pigs to PPV was observed from day 101 onwards. In contrast, PBMC from mock-infected pigs did not proliferate in response to PPV. Flow cytometric analysis indicated that the CD4+CD8+ T-cell subset of PBMC proliferated in response to virus antigen, in keeping with the assumed role for these cells in immunological memory. This is, to our knowledge, the first indication of a cellular immune response following PPV infection. A weak CTL activity, which peaked on days 80 and 87, was observed in PPV-infected pigs. In vitro restimulation of PBMC with live PPV did not induce further CTL activity. A pronounced NK cell activity was detected in both virus-infected and control pigs throughout the experiment, and may have negatively affected the sensitivity of the CTL assay. In conclusion, the findings of a late lymphoproliferative response together with weak CTL activity are in keeping with an effective control of acute PPV infection by humoral immunity, but open the possibility that cellular immunity may play a role in controlling PPV reinfection. Finally, we find that the established experimental model using SLA characterized pigs may constitute a valuable tool for future studies of CTL activity in pigs.

Animals↗
PubMed2002

Cytokine profiles in peripheral blood mononuclear cells and lymph node cells from piglets infected in utero with porcine reproductive and respiratory syndrome virus.

The aim of the present study was to investigate at 2, 4, and 6 weeks after birth cytokine expression by peripheral blood mononuclear cells and bronchial lymph node cells from piglets infected in utero with porcine reproductive and respiratory syndrome virus (PRRSV). Technically, by flow cytometry we were able to measure gamma interferon (gamma-IFN), tumor necrosis factor alpha (TNF-alpha), interleukin-4 (IL-4), and IL-8 levels. In general, we found increases in the percentages of IL-4-, gamma-IFN-, and TNF-alpha-producing lymphocytes in the infected piglets compared to the percentages in the uninfected control animals, while there was a decrease in the percentage of IL-8-producing monocytes. We believe that these findings reflect a general lymphocyte activation stage that is created due to the infection and that occurs in combination with impairment of the monocyte function, possibly due to the ongoing viral replication in these cells. Single-cell bronchial lymph node preparations exhibited very much the same cytokine profiles as peripheral blood mononuclear cells except for a lack of IL-8 production. When the levels of the individual cytokines in the three groups of PRRSV-infected piglets were compared, the levels of cytokine expression at 4 weeks diverged from those at 2 and 6 weeks, in that there was a significant decrease in the numbers of lymphocytes producing gamma-IFN and TNF-alpha. This tendency was also observed among blood monocytes and lymph node macrophages. Possible reasons for this temporary immunosuppression in the piglets at 4 weeks are discussed.

Animals↗
PubMed2002

Incidence of asthma in female Swedish hairdressers.

OBJECTIVE: To investigate the risk of asthma in hairdressers. METHODS: The incidence of asthma was retrospectively estimated in a Swedish nationwide study including all female hairdressers certified from vocational schools from 1970 to 1995, and a stratified sample of women from the general population were referents. A postal questionnaire included questions on respiratory tract symptoms, atopy, smoking, working periods as a hairdresser, and number of specific hair treatments performed/week. Reported exposures were validated by occupational hygienists. Rate ratios of incidence (IRRs) of asthma were estimated by Poisson regression, adjusted for calendar year of observation, hay fever, smoking, and region of domicile. RESULTS: The crude incidences of asthma/1000 person-years were: 3.9 during active years as a hairdresser, 2.8 among the hairdressers when not working in the profession, and 3.1 among the referents. The corresponding IRR for being an active hairdresser compared with the referents was 1.3 (95% confidence interval (95% CI) 1.0 to 1.6). Moderate effects on risk of asthma were found both from hairdressing work (IRR=1.6 (1.1 to 2.2) among never-smokers) and from smoking (IRR=1.6 (1.2 to 2.2) among referents). However, the combined effect from hairdressing work and smoking (IRR=1.5 (1.0 to 2.1)) was less than expected (p=0.02). No effect modification by respiratory atopy was found. The hairdressers most often performing hair bleaching treatments (IRR=1.5 (0.7 to 3.0)) or using hair spray (IRR=1.4 (0.8 to 2.4)) had, compared with the most infrequent users, a slightly, but not significantly higher incidence of asthma. Exposure to persulphates in hair bleach was estimated to be 0.04-0.15 mg/m(3) during mixing of the powder. Reported average number of bleaching treatments agreed well with those performed according to a diary. CONCLUSIONS: Active hairdressing work was associated with a moderately increased incidence of asthma among lifelong non-smokers. The results are moderately supportive, but not conclusive, of associations between asthma and exposure to hair bleach or hair spray.

Adult↗
PubMed2002

Associations between markers of respiratory morbidity in European children.

School-aged children often experience acute respiratory symptoms. In a multicentre European study, the association between chronic respiratory symptoms (reported in a questionnaire), skin-prick test results, and lung function, and the occurrence of acute respiratory morbidity, was examined among children aged 6-12 yrs with chronic respiratory symptoms. Children with chronic respiratory symptoms, living in 10 European countries, were selected from a parent-completed questionnaire (n=4,307). Atopy was measured with skin-prick tests, and lung function with spirometry. A total of 1,854 (86% of those in the initial cohort) children kept a successful daily diary regarding their respiratory symptoms for 2-3 months. In multivariate logistic regression analyses, children with asthmatic symptoms, particularly those with doctor-diagnosed asthma, had a greater risk of occurrence of lower respiratory symptoms (odds ratio (OR): 6.12; 95% confidence interval (CI): 4.99-8.35) than children with a dry nocturnal cough as their only symptom. Atopy, particularly a positive reaction to indoor allergens, was significantly associated with occurrence of lower respiratory symptoms. For atopy the OR was 1.62 (95% CI: 1.34-1.96). A reduced level of maximal mid-expiratory flow was associated with an increased risk of lower respiratory symptoms, cough and phlegm. The associations were similar in Scandinavia, Central Eastern, Western and Southern Europe. To conclude, asthmatic symptoms reported in a questionnaire, atopic status and a reduced level of maximal mid-expiratory flow were associated with the occurrence of acute respiratory symptoms, especially those of lower respiratory symptoms.

Acute Disease↗
PubMed2001

Simple and robust method for estimation of the split between the oxidative pentose phosphate pathway and the Embden-Meyerhof-Parnas pathway in microorganisms.

The flux through the oxidative pentose phosphate (PP) pathway was estimated in Bacillus clausii, Saccharomyces cerevisiae, and Penicillium chrysogenum growing in chemostats with [1-(13)C]glucose as the limiting substrate. The flux calculations were based on a simple algebraic expression that is valid irrespective of isotope rearrangements arising from reversibilities of the reactions in the PP pathway and the upper part of the Embden-Meyerhof-Parnas pathway. The algebraically calculated fluxes were validated by comparing the results with estimates obtained using a numerical method that includes the entire central carbon metabolism. Setting the glucose uptake rate to 100, the algebraic expression yielded estimates of the PP pathway flux in B. clausii, S. cerevisiae, and P. chrysogenum of 20, 42, and 75, respectively. These results are in accordance with the results from the numerical method. The information on the labeling patterns of glucose and the proteinogenic amino acids were obtained using gas chromatography / mass spectrometry, which is a very sensitive technique, and therefore only a small amount of biomass is needed for the analysis. Furthermore, the method developed in this study is fast and readily accessible, as the calculations are based on a simple algebraic expression.

Bacillus↗
PubMed2001

Ty1 retrotransposition and programmed +1 ribosomal frameshifting require the integrity of the protein synthetic translocation step.

Programmed ribosomal frameshifting is utilized by a number of RNA viruses to ensure the correct ratio of viral structural to enzymatic proteins for viral particle assembly. Altering frameshifting efficiencies upsets this ratio, inhibiting virus propagation. Two yeast viruses that induce host cell ribosomes to shift translational reading frame were used as tools to explore the interactions between viruses and host cellular protein synthetic machinery. Previous studies showed that the ribosome-inactivating protein pokeweed antiviral protein specifically inhibited propagation of the Ty1 retrotransposable element of yeast as a consequence of inhibition of programmed +1 ribosomal frameshifting. Here, complementary genetic and pharmacological approaches were employed to test whether inhibition of Ty1 retrotransposition is a general feature of alterations in the translocation step of elongation and +1 frameshifting. The results demonstrate that cells harboring a variety of mutant alleles of two host-encoded proteins that are involved in translocation, eukaryotic elongation factor-2 and the ribosome-associated protein RPP0, have Ty1 propagation defects. We also show that sordarin, a fungus-specific inhibitor of eEF-2 function, specifically inhibits programmed +1 ribosomal frameshifting and Ty1 retrotransposition. These findings serve to link inhibition of Ty1 retrotransposition and +1 frameshifting to changes in the translocation step of elongation.

Frameshifting, Ribosomal↗
PubMed2001

Summary of workshop findings for porcine T-lymphocyte-specific monoclonal antibodies.

Fifty-seven monoclonal antibodies (mAb) selected after the first round analyses in the Third International Swine CD workshop for their possible reactivity with T-lymphocyte specific antigens were further analysed in a second round. As target cells for flow cytometric analyses served peripheral blood mononuclear cells, nylon-wool enriched T-lymphocytes, thymocytes, splenocytes, and lymphocytes derived from Peyer's patches. These second round analyses revealed 15 different data sets. Together with 22 pre-selected data sets from the first round analyses with the whole panel of monoclonal antibodies, 37 data sets were used for the clustering of the respective mAb. Using the LTDB4 program, 19 preliminary clusters could be defined. Two clusters (C3 and C7) with 4 mAb showed no labelling of resting T-lymphocytes. Seven clusters (C1, C2, C4, C5, C6, C11, and C12) contain mAb (in total: 16 mAb) directed against subsets of CD4(-)CD8(-) T-lymphocytes. These mAb seem to recognise antigens on porcine T-lymphocytes with T-cell receptor (TcR) gamma/delta chains. Three clusters (C8, C9, C10, C13) seem to be artificial. They contain either mAb staining CD4(-)CD8(-) T-lymphocytes and low CD8+ cells (C8, C9), mAb with various reactivity (C10) and mAb with known differences in their reactivity (C13). Cluster C14 contains 3 mAb against the CD4a-epitope, C15 describes mAb directed against porcine CD8c-epitope whereas mAb against CD8a and CD8b-epitopes grouped in C19. The mAb found in C16 seem to recognise CD45R. Cluster C17 is composed of different standards directed against CD2, CD3, CD5 and wCD6. Two additional mAb recognising the CD2a-epitope could be enclosed. C18 contains two mAb directed against SWC2.

Animals↗
PubMed2001

Overview of the Third International Workshop on Swine Leukocyte Differentiation Antigens.

The aim of the Third International Workshop on Swine Leukocyte Differentiation Antigens (CD workshop), supported by the Veterinary Immunology Committee (VIC) of the International Union of Immunological Societies (IUIS), was to standardize the assignment of monoclonal antibodies (mAb) reactive with porcine leukocyte differentiation antigens and to define new antibody clusters, using nomenclature in accordance with human and ruminant CD nomenclature, as agreed at the summary meeting of the Second International Swine CD Workshop in Davis, 1995: only mAb with proven reactivity for the orthologous porcine gene product or cross-reactivity for the human gene products, were given the full CD nomenclature, all other allocations were prefixed with "w". As in previous workshops, the overall organization was entrusted to the chair and first author, with support by the chair of the previous workshop and second author. In addition to the existing 26 pig leukocyte CD/SWC determinants established in previous workshops, this workshop established/confirmed another 11 CDs for pig leukocytes, identified by a total of 21 mAb: CD11R1 (2 mAb), CD11R2 (1 mAb), CD11R3 (4 mAb), wCD40 (1 mAb), wCD46 (4 mAb), wCD47 (3 mAb), wCD49d (1 mAb), CD61 (1 mAb), wCD92 (1 mAb), wCD93 (1 mAb) and CD163 (2 mAb).

Animals↗
PubMed2001

Summary of the first round analyses of the Third International Workshop on Swine Leukocyte Differentiation Antigens.

The reactivity of 155 monoclonal antibodies submitted to the Third International Workshop on Swine Leukocyte Differentiation Antigens, together with 41 internal standards, was analysed by flow cytometry on 29 different pig cell targets as well as two human cell targets as a means of establishing suitable panels of monoclonal antibodies for more detailed clustering analyses by the various subsections of the workshop. Results were collected either without further gating, with gating based on FS/SS characteristics or with gating based on the co-expression of a reference antibody in two-colour flow cytometry. The CD or SWC reactivity of the internal standards had been established in previous workshops. Data sets were subsequently analysed by statistical clustering using the Leucocyte Typing Database IV software. The resulting 18 cluster groups were allocated to the appropriate second round sections of the workshop, after reviewing the overall cellular reactivity of each cluster as well as the specificity of known standards which clustered in a group.

Animals↗
PubMed2001

5-(2-pyridyl)-1,3-dithiane-2-thione.

The title compound, C9H9NS3, crystallizes with two molecules in the asymmetric unit. In both molecules, the dithiane-2-thione rings adopt a symmetric half-boat conformation with the C atom opposite the C--S(thione) bond out of the plane. The pyridine ring is in an equatorial position and is twisted out of the plane of the half-boat by 82.7 (2) and 84.5 (2) degrees in the two molecules, so that the N atom is trans to the axial C--H bond in both cases.

Journal Article↗
PubMed2001

In vivo dynamics of galactose metabolism in Saccharomyces cerevisiae: metabolic fluxes and metabolite levels.

The dynamics of galactose metabolism in Saccharomyces cerevisiae was studied by analyzing the metabolic response of the CEN.PK 113-7D wild-type strain when exposed to a galactose pulse during aerobic growth in a galactose-limited steady-state cultivation at a dilution rate of 0.097 h(-1). A fast sampling technique and subsequent methanol-chloroform/solid phase extractions were applied for in vivo measurements of the dynamic changes of the AMP, ADP, ATP levels and the sugar phosphates of the Leloir pathway. The ATP level was found to be significantly lower for yeast growing under galactose limitation (0.37 +/- 0.05 micromol/g CDW) than what has been reported for growth under glucose limitation. The galactose pulse of 5.58 mM was consumed within 40 min (t = 40) and 7 min after the pulse was added cell growth stopped. Subsequently, the cells started to grow and at t = 30 the specific growth rate had recovered to half the steady-state growth rate (0.047 h(-1)). To evaluate the change in flux distribution at steady state and during the galactose transient, a stoichiometric model describing the aerobic metabolism of S. cerevisiae was set up for quantification of the metabolic fluxes. At t = 7 the flux entering the TCA cycle was low and acetate and ethanol started to be excreted to the extracellular medium. During recovery of cell growth the flux entering the TCA cycle increased again, and at t = 30 this flux exceeded the corresponding steady-state flux. During the pulse an enhanced level of Gal-1P was measured, which may be responsible for a toxic metabolic response in S. cerevisiae. The increase in the Gal-1P concentration is intensified by the low affinity of Gal7 towards Gal-1P and, hence, under the physiological conditions examined Gal7 seems to exert control over flux through the Leloir pathway.

Adenine Nucleotides↗
PubMed2001

Transcranial magnetic stimulation and stretch reflexes in the tibialis anterior muscle during human walking.

Stretch of the ankle dorsiflexors was applied at different times of the walking cycle in 17 human subjects. When the stretch was applied in the swing phase, only small and variable reflex responses were observed in the active tibialis anterior (TA) muscle. Two of the reflex responses that could be distinguished had latencies which were comparable with the early (M1) and late (M3)components of the three reflex responses (M1, M2 and M3) observed during tonic dorsiflexion in sitting subjects. In the stance phase a single very large response was consistently observed in the inactive TA muscle. The peak of this response had the same latency as the peak of M3, but in the majority of subjects the onset latency was shorter than that of M3. The TA reflex response in the stance phase was abolished by ischaemia of the lower leg at the same time as the soleus H-reflex, suggesting that large muscle afferents were involved in the generation of the response. Motor-evoked potentials (MEPs) elicited in the TA by transcranial magnetic stimulation (TMS) were strongly facilitated corresponding to the peak of the stretch response in the stance phase and the late reflex response in the swing phase. A similar facilitation was not observed corresponding to the earlier responses in the swing phase and the initial part of the response in stance. Prior stretch did not facilitate MEPs evoked by transcranial electrical stimulation in the swing phase of walking. However, in the stance phase MEPs elicited by strong electrical stimulation were facilitated by prior stretch to the same extent as the MEPs evoked by TMS. The large responses to stretch seen in the stance phase are consistent with the idea that stretch reflexes are mainly involved in securing the stability of the supporting leg during walking. It is suggested that a transcortical reflex pathway may be partly involved in the generation of the TA stretch responses during walking.

Adult↗
PubMed2001

Quantitative analysis of Penicillium chrysogenum Wis54-1255 transformants overexpressing the penicillin biosynthetic genes.

The low penicillin-producing, single gene copy strain Wis54-1255 was used to study the effect of overexpressing the penicillin biosynthetic genes in Penicillium chrysogenum. Transformants of Wis54-1255 were obtained with the amdS expression-cassette using the four combinations: pcbAB, pcbC, pcbC-penDE, and pcbAB-pcbC-penDE of the three penicillin biosynthetic genes. Transformants showing an increased penicillin production were investigated during steady-state continuous cultivations with glucose as the growth-limiting substrate. The transformants were characterized with respect to specific penicillin productivity, the activity of the two pathway enzymes delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine synthetase (ACVS) and isopenicillin N synthetase (IPNS) and the intracellular concentration of the metabolites: delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV), bis-delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (bisACV), isopenicillin N (IPN), glutathione (GSH), and glutathione disulphide (GSSG). Transformants with the whole gene cluster amplified showed the largest increase in specific penicillin productivity (r(p))-124% and 176%, respectively, whereas transformation with the pcbC-penDE gene fragment resulted in a decrease in r(p) of 9% relative to Wis54-1255. A marked increase in r(p) is clearly correlated with a balanced amplification of both the ACVS and IPNS activity or a large amplification of either enzyme activity. The increased capacity of a single enzyme occurs surprisingly only in the transformants where all the three biosynthetic genes are overexpressed but is not found within the group of pcbAB or pcbC transformants. The indication of the pcbAB and pcbC genes being closely regulated in fungi might explain why high-yielding strains of P. chrysogenum have been found to contain amplifications of a large region including the whole penicillin gene cluster and not single gene amplifications. Measurements of the total ACV concentration showed a large span of variability, which reflected the individual status of enzyme overexpression and activity found in each strain. The ratio ACV:bisACV remained constant, also at high ACV concentrations, indicating no limitation in the capacity of the thioredoxin-thioredoxin reductase (TR) system, which is assumed to keep the pathway intermediate LLD-ACV in its reduced state. The total GSH pool was at a constant level of approx. 5.7 mM in all cultivations.

Culture Media↗
PubMed2001

Expression of a cytoplasmic transhydrogenase in Saccharomyces cerevisiae results in formation of 2-oxoglutarate due to depletion of the NADPH pool.

The intracellular redox state of a cell is to a large extent defined by the concentration ratios of the two pyridine nucleotide systems NADH/NAD(+) and NADPH/NADP(+) and has a significant influence on product formation in microorganisms. The enzyme pyridine nucleotide transhydrogenase, which can catalyse transfer of reducing equivalents between the two nucleotide systems, occurs in several organisms, but not in yeasts. The purpose of this work was to analyse how metabolism during anaerobic growth of Saccharomyces cerevisiae might be altered when transfer of reducing equivalents between the two systems is made possible by expression of a cytoplasmic transhydrogenase from Azotobacter vinelandii. We therefore cloned sth, encoding this enzyme, and expressed it under the control of a S. cerevisiae promoter in a strain derived from the industrial model strain S. cerevisiae CBS8066. Anaerobic batch cultivations in high-performance bioreactors were carried out in order to allow quantitative analysis of the effect of transhydrogenase expression on product formation and on the intracellular concentrations of NADH, NAD(+), NADPH and NADP(+). A specific transhydrogenase activity of 4.53 U/mg protein was measured in the extracts from the strain expressing the sth gene from A. vinelandii, while no transhydrogenase activity could be detected in control strains without the gene. Production of the transhydrogenase caused a significant increase in formation of glycerol and 2-oxoglutarate. Since NADPH is used to convert 2-oxoglutarate to glutamate while glycerol formation increases when excess NADH is formed, this suggested that transhydrogenase converted NADH and NADP(+) to NAD(+) and NADPH. This was further supported by measurements of the intracellular nucleotide concentrations. Thus, the (NADPH/NADP(+)):(NADH/NAD(+)) ratio was reduced from 35 to 17 by the transhydrogenase. The increased formation of 2-oxoglutarate was accompanied by a two-fold decrease in the maximal specific growth rate. Also the biomass and ethanol yields were significantly lowered by the transhydrogenase.

Amino Acid Sequence↗
PubMed2001

[Laparoscopic fundoplication. A prospective assessment of 100 operations for gastroesophageal reflux].

INTRODUCTION: Laparoscopic fundoplication was assessed in a prospective study. METHOD: One hundred patients with gastroesophageal reflux (GORD) were treated by a 360 degrees fundoplication. The number of operations completed as a laparoscopic procedure, the complication rate, the length of hospital stay and time of work and the effect on GORD symptoms were used as endpoints. RESULTS: The operations could be performed as a laparoscopic procedure in 97 cases. Complications were few: A left-sided pneumothorax in two patients. Median operating time was 100 min and postoperative hospital stay two days. Sufficient reflux control was obtained in 93 patients. Only minor side effects were encountered in three patients (dysphagia two, flatulence one). At three-month control 91 were satisfied. After 3-49 mo (median 19 mo) two have needed a re-operation for dysphagia (one due to tight suture and one for a rotated fundoplication). One patient had the fundoplication taken down for embarrassing flatulence in spite of successful reflux control. CONCLUSION: Laparoscopic fundoplication offers a good immediate control of GORD during a short hospitalization with few complications or side effects. No long term results are available at present.

Adult↗
PubMed2001

C-MYC and IGF-II mRNA-binding protein (CRD-BP/IMP-1) in benign and malignant mesenchymal tumors.

Mouse coding region determinant-binding (mCRD-BP) and human IGF-II mRNA-binding 1 (hIMP-1) proteins are orthologous mRNA-binding proteins that recognize c-myc and IGF-II mRNA, respectively, and regulate their expression posttranscriptionally. Here, we confirm that human CRD-BP/IMP-1 binds to c-myc mRNA and that it is predominantly expressed in fetal tissues. Moreover, hCRD-BP/IMP-1 expression was detected in cell lines of neoplastic origin and in selected primary tumors. In a series of 33 malignant and 10 benign mesenchymal tumors, 73% and 40%, respectively, were found to express hCRD-BP/IMP-1. In particular, expression was significant in 14 Ewing's sarcomas, all of which were positive. The data suggest that hCRD-BP/IMP-1 plays a role in abnormal cell proliferation in mesenchymal tumors.

Amino Acid Motifs↗