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R Berger

Publications and source records attributed to R Berger.

At least 217 records · Page 12Linked to original sources
PubMed1997

Ubiquitous expression of a cloned murine thymopoietin cDNA.

Thymopoietin (TP) was originally isolated as a 5-kD 49-aa protein from bovine thymus and was subsequently observed to affect T-cell differentiation and function. We report here the molecular cloning of a murine TP cDNA. The 2,514 bp fragment contains a 630 bp open reading frame that encodes for 210 aa, highly homologous to the first 220 aa of the human TP beta and TP gamma isoforms and to bovine TP. Southern blot analysis of genomic DNA revealed that in mouse, calf and human TP is encoded by a single genomic locus. Recently, it was found that one of the TP isoforms designated TP beta is a homologous protein to the lamina-associated polypeptide 2 (LAP2), which is thought to play an important role in the regulation of nuclear architecture by binding lamin B1 and chromosomes in a manner regulated by phosphorylation during mitosis. In this study we report the TP expression at the transcription level in 17 murine and rat tissues of different origins and 18 lymphoid and nonlymphoid cell lines. The assessment of TP mRNA expression by S1-nuclease protection assays and in situ hybridizations revealed that its expression is not exclusive to thymus, but rather ubiquitous, higher in lymphatic tissues, but also in other cells characterized with a high rate of proliferation. TP was also shown to be expressed in athymic and old animals, lacking a functional thymus gland. Further in situ hybridization studies revealed that within the thymus, the highest levels of TP mRNA are noted at the cortex. These results suggest a possible role for TP in proliferation and cell cycle control.

Amino Acid Sequence↗
PubMed1997

Regional cerebral glucose utilization in immature fetal guinea pigs during maternal isocapnic hypoxemia.

Recent studies in immature fetal animals demonstrated only a slight or variable increase in the cerebral glycolytic rate during moderate isocapnic hypoxemia. However, the methods used in those studies did not allow for detection of small differences or of regional redistributions of the cerebral glycolytic rate. Hence, a global increase or a regional redistribution of the cerebral glycolytic rate during hypoxemia accompanied by a severe increase in tissue lactate concentration in a few brain areas may have been overlooked in these studies. Because these pathophysiologic mechanisms seem to considerably exacerbate neuronal cell damage due to hypoxic/ischemic insults, we were keen to clarify this point. We, therefore, applied the 2-deoxyglucose method to fetal guinea pigs in utero and measured total and regional cerebral glucose utilization in fetuses of this species at 0.75 of gestation during maternal isocapnic hypoxemia. At 0.75 of gestation guinea pig dams were chronically catheterized. Control groups were exposed to room air, whereas study groups were exposed to a hypoxic atmosphere (10% oxygen, 2% carbon dioxide, and 88% nitrogen). To measure total and regional cerebral glucose utilization during normoxemia and isocapnic hypoxemia, we injected i.v. 100 microCi of 2-[3H]deoxyglucose into the dams. Total and regional cerebral glucose utilization were determined from the steady-state clearance of 2-deoxyglucose between the maternal arterial plasma and the fetal brain, the glucose concentration in the maternal arterial plasma, and the "lumped constant." During isocapnic hypoxemia, total fetal cerebral glucose utilization was not significantly higher than that previously measured during normoxemia (8 +/- 0.8 versus 8 +/- 1.0 micromol/100 g/min). Furthermore, no redistribution of cerebral glucose utilization could be detected. We conclude that moderate isocapnic hypoxemia in the immature fetal brain does not lead to any significant increase or redistribution of glucose utilization or to any major lactate accumulation. This may be related to the low cerebral metabolic demands of brain tissue at this stage of development. Whether this is the main reason for the known resistance of the immature fetal brain toward ischemic neuronal cell damage remains to be established.

Animals↗
PubMed1997

Hemodynamic and neurohumoral effects of long-term prostaglandin E1 infusions in outpatients with severe congestive heart failure.

BACKGROUND: Prostaglandins of the E type are potent endogenous vasodilators that also interfere with the activity of the sympathetic nervous system. Thus treating patients with end-stage heart failure with prostaglandin E1 (PGE1) infusions seems to accord well with the hypothesis that neurohumoral imbalance rather than hemodynamic derangements should be the priority in the treatment of heart failure. METHODS: We sought to investigate neurohumoral in addition to hemodynamic changes during long-term PGE1 infusion and determined plasma renin activity, atrial natriuretic peptide, norepinephrine, and big endothelin plasma levels in 13 male patients with heart failure whose symptoms remained severe in spite of optimized oral therapy with digitalis, nitrates, furosemide (185 +/- 72 mg/d) and enalapril (33 +/- 3 mg/d). PGE1 infusion rate was started with 2.5 ng/kg/min and stepwise increased to the maximum tolerated dose (26 +/- 4 ng/kg/min), which was halved for continuous infusion through the following 12 hours and further stepwise reduced to an average dose of 8 +/- 1 ng/kg/min. Right heart catheterization was performed for acute hemodynamic studies and after 4 weeks. All patients were discharged with a catheter that was connected to a portable pump for home therapy. RESULTS: Acute effects of PGE1 were reductions in systemic blood pressure, (p < 0.05), right atrial pressure (p < 0.001), pulmonary artery pressure (p < 0.05), pulmonary capillary wedge pressure (p < 0.01), systemic and pulmonary vascular resistance index (both p < 0.01) and an increase in cardiac and stroke volume index (both p < 0.001) without a change in heart rate. After 4 weeks a persistent increase from baseline in cardiac index (from 1.9 +/- 0.1 to 2.5 +/- 0.2 L/min/m2; p < 0.01) and in pulmonary vascular resistance index (from 479 +/- 50 to 331 +/- 29 dynes x sec/cm5 x m2; p < 0.05) was observed. Atrial natriuretic peptide (p < 0.05) decreased, and norepinephrine and big endothelin showed a tendency to a lower level. Concomitantly, New York Heart Association functional class changed (p = 0.0001), with one patient's condition remaining class IV, the conditions of seven patients decreasing to class II, and the conditions of five patients decreasing to class III. CONCLUSION: Thus long-term parenteral home therapy with PGE1 infusions in patients with severe end-stage heart failure elicited beneficial clinical and hemodynamic effects without activating neurohumoral counterregulatory systems.

Alprostadil↗
PubMed1997

FISH analysis of translocations involving the short arm of chromosome 9 in lymphoid malignancies.

Deletion of the short arm of chromosome 9 (9p), resulting in the loss of the p16INK4a/MTS1 gene, now called CDKN2, has been found to occur frequently in acute lymphoblastic leukemia, even in the absence of a microscopically visible deletion. In this study, we have used YAC probes encompassing the CDKN2 locus to analyze by fluorescence in situ hybridization patients with leukemia and lymphoma and translocations involving 9p in order to establish the CDKN2 status in relation to the karyotype. We found that, in leukemic cells exhibiting loss of heterozygosity at the CDKN2 locus, the deleted allele was from the cytogenetically normal chromosome 9, whereas the other allele was located on a rearranged chromosome. This finding suggests that CDKN2 gene loss is nonrandomly associated with 9p translocation in lymphoid proliferations. Genes Chromosom.

Adult↗
PubMed1997

Prostaglandin E1 infusion compared with prostacyclin infusion in patients with refractory heart failure: effects on hemodynamics and neurohumoral variables.

Prostaglandin E1 or prostacyclin were randomly infused in 18 patients with severe chronic heart failure who did not respond to oral treatment. Maximally tolerated dosages of both agents increased cardiac index; however, only prostacyclin decreased mean arterial pressure and increased plasma norepinephrine significantly. Twelve hours after 50% peak dose reduction, atrial natriuretic peptide levels, right atrial pressure, mean pulmonary artery pressure, and mean arterial pressure continued to decrease with prostaglandin E1, whereas the increase in cardiac index was sustained; in contrast, at 50% prostacyclin dose reduction, cardiac index decreased toward baseline, suggesting that, with reduced dosages for chronic infusions, desired hemodynamic changes seem to be sustained with prostaglandin E1 only.

Alprostadil↗
PubMed1997

Mutation analysis for prenatal diagnosis of hereditary tyrosinaemia type 1.

Hereditary tyrosinaemia type 1 is a rare but serious metabolic disorder with an autosomal recessive mode of inheritance. We describe the prenatal diagnosis of an affected fetus performed by DNA-mutation analysis and a subsequent pregnancy with a healthy child in the same family.

Amino Acid Metabolism, Inborn Errors↗
PubMed1996

Localization of the L-glutamine synthetase gene to chromosome 1q23.

Glutamine synthetase (E.C. 6.3.1.2) is expressed throughout the body and plays an important role in controlling body pH and in removing ammonia from the circulation. The enzyme clears L-glutamate, the major neurotransmitter in the central nervous system, from neuronal synapses. The enzyme is a very sensitive marker of many disease and aging processes, especially those involving reactive oxygen species. This report describes the localization of the enzyme to chromosome 1 by PCR analysis of a human/rodent somatic cell hybrid panel. We also describe the localization of a recently described pseudogene to chromosome 9. Further localization of the glutamine synthetase gene locus to 1q23 was accomplished by fluorescence in situ hybridization. The glutamine synthetase gene was mapped to five CEPH megaYACs between the polymorphic PCR markers D1S117 and D1S466 by analysis of the Whitehead Institute's recently described chromosome 1 contig map.

Animals↗
PubMed1996

Chromosomal assignment of the human gene encoding the Fos-related antigen-2 (FRA2) to chromosome 2p22-p23.

The four members of the Fos gene family give rise to proteins that are part of the AP-1 transcription factor complex. When studying cAMP-induced apoptosis in a leukemia cell line from rat, we found that the Fra-2 gene (coding for the Fos-related antigen-2) became strongly upregulated as the leukemia cells started to die. It was therefore of interest to determine the cytogenetic localization of the human Fra-2 gene (FRA2), including a comparison to chromosomal aberrations observed in leukemia patients. Based on sequence information from the rat and chicken Fra-2 homologs, we were able to PCR-amplify a 4.5-kb genomic fragment covering exon 4 of FRA2. This fragment was employed as probe for both radioactive and fluorescence in situ hybridization to human metaphase chromosomes, allowing us to assign FRA2 to 2p22-p23. The localization of the gene to chromosome 2 was independently verified by PCR amplification of a FRA2-specific fragment from a panel of rodent-human somatic cell hybrids.

Animals↗
PubMed1996

Inadequate production of hematopoietic growth factors in hairy cell leukemia: up-regulation of interleukin 6 by recombinant IFN-alpha in vitro.

The course of hairy cell leukemia (HCL) is characterized by progressive pancytopenia. The pathogenesis of this phenomenon is still not fully understood. To study if the decrease in hematopoiesis in HCL is accompanied by abnormal concentrations of growth factors, we investigated the production of granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, interleukin 3 (IL-3), interleukin 6 (IL-6), and tumor necrosis factor alpha by peripheral blood mononuclear cells (PBMCs) of eight patients with HCL. The results point to a severe deficiency of production of all cytokines tested as compared to healthy donors. However, enrichment of autologous monocytes by counterflow centrifugation resulted in a marked increase of the levels of granulocyte colony-stimulating factor, granulocyte-macrophage colony-stimulating factor, IL-6, and tumor necrosis factor alpha. The most pronounced effects were seen with IL-6. Reverse transcription-PCR analysis indicated that pokeweed mitogen, IFN-alpha, and poly(I:C) are capable of inducing the expression of IL-6-specific mRNA in HCL cells. These findings are substantiated on the protein level by immunofluorescence analysis. Incubation of PBMCs with IFN-alpha resulted in a significant increase of intracellular IL-6 in HCL but not in healthy donors. This increase was also seen in hairy cells positive for CD19 and CDllc. Furthermore, IFN-alpha induced the secretion of IL-6 from PBMCs of HCL patients but not healthy donors. In conclusion, our studies with PBMCs from patients with HCL revealed an inadequate supply of hematopoietic growth factors that might, in part, be due to the monocytopenia characteristic for this disease. The findings also indicate that IFN-alpha is capable of inducing the production of IL-6 in the patients' PBMCs as well as in their hairy cells. These data from our in vitro studies support the clinical observation that treatment with IFN-alpha leads to reconstitution of hematopoiesis.

Adult↗
PubMed1996

Partial deletion of the long arm of chromosome 5: a fluorescence in situ hybridization study using band-specific painting probes generated by chromosome microdissection.

A series of 17 patients with myeloid disorders and partial deletions of the long arm of chromosome 5 were investigated using fluorescence in situ hybridization with 5q34-q35 region-specific painting probes generated by chromosome microdissection. This approach confirmed that partial 5q deletions are interstitial in all the cases studied. In addition no translocation involving chromosome 5 was detected.

Adult↗
PubMed1996

Quantitation of the putative neurotransmitter agmatine as the hexafluoroacetylacetonate derivative by stable isotope dilution gas chromatography and negative-ion chemical ionization mass spectrometry.

A method is described for detection and quantitation of agmatine [4-(aminobutyl)guanidine] by gas chromatography/negative-ion chemical ionization/mass spectrometry after derivatization with hexafluoroacetylacetone. The lower limit of detection of the derivative was about 25 fmol on-column. For quantitative studies of agmatine content in biological samples, a procedure utilizing an internal standard ([15N4]agmatine prepared from [15N4]arginine) and an extraction step had a lower limit of detection of about 15 pmol for total sample content. Agmatine content was measured in rat tissue samples and normalized to protein content. Kidney and spleen samples exhibited the greatest content of agmatine per unit protein mass but agmatine was also detected in pancreatic islets and brain regions (cerebellum and cerebral cortex). On the basis of these measurements, it is estimated that the pancreatic islet intracellular agmatine concentration may exceed 1 microM. The sensitive and highly specific means of detection and quantitation provided by mass spectrometry may be useful in investigating the physiological role of agmatine in mammalian systems.

Agmatine↗
PubMed1996

Genomic organization of the human ERM (ETV5) gene, a PEA3 group member of ETS transcription factors.

The ERM protein belongs to the family of Ets transcription factors. We show here that the human ERM gene is organized into 14 exons distributed along 65 kb of genomic DNA on chromosome 3. The two main functional domains of ERM, the acidic domain and the DNA-binding ETS domain, are overlapped by three different exons each. The 3'-untranslated region of ERM is 2.1 kb, whereas the 5'-untranslated region is about 0.3 kb; this allows the transcription of ERM transcripts of approximately 4 kb. The human ERM gene is localized to the q27-q29 region of chromosome 3.

Amino Acid Sequence↗
PubMed1996

Human short-chain L-3-hydroxyacyl-CoA dehydrogenase: cloning and characterization of the coding sequence.

The cDNA encompassing the complete coding sequence of human liver short-chain L-3-hydroxyacyl-CoA dehydrogenase (SCHAD) was isolated and characterized. Screening of a cDNA library combined with rapid amplification of 5' cDNA ends resulted in a SCHAD cDNA sequence of 1877 bp. It encodes a protein of 314 amino acids with a calculated molecular weight of 34.3 kDA containing a mitochondrial import signal peptide of 12 amino acids and 302 amino acids of mature SCHAD protein. The deduced amino acid sequence of the mature protein shows a 92 percent identity with SCHAD from pig heart. Northern blot analysis reveals SCHAD mRNA to be expressed in liver, kidney, pancreas, heart and skeletal muscle. The human SCHAD gene was mapped by fluorescence in situ hybridization to chromosome 4q22-26.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed1996

Evaluation of six anti-gliadin antibody assays.

Two in-house methods developed in gastroenterological laboratories for the detection and quantitation of IgG and IgA antibodies to gliadin (AGA) were compared with three commercially available ELISAs (gluten IgG/IgA EIA, Kabi Pharmacia, Sweden; alpha-Gliatest, Eurospital, Italy; AGA Orkit, Labodia, Switzerland) and one qualitative rapid assay (Gliastick, Eurospital, Italy). 67 acute, biopsy confirmed coeliac disease cases were compared with 54 biopsy confirmed disease controls. The result of anti-endomysium antibody (AEA) testing was available from all cases. The testing of 121 sera in different test systems permitted comparison of the range of concentration and sensitivity of the quantitative IgG and IgA anti-gliadin tests. Each test uses its own arbitrary calibration. To permit direct comparison of the different test ranges the values of the different positive reference sera were converted into Pharmacia arbitrary units (AU). The AGA and IgG tests ranged from 0 to a maximum of 157-430 AU and the maximum IgA test results from 81 to 855 AU. This illustrates the need for an internationally accepted standard. All three EIA kits met the performance claims of the manufacturers and were easy to use. Most results agreed with the clinical diagnosis when the sera were positive for anti-endomysium antibodies. However, AEA negative specimens showed a considerable incidence of positive AGA in non-coeliacs. The study emphasises the need to test for both AGA and AEA in order to reliably diagnose coeliac disease. The qualitative test showed a high degree of false positive results and could be used to monitor the dietary compliance of coeliac patients.

Acute Disease↗
PubMed1996

Establishment of a human acute promyelocytic leukemia-ascites model in SCID mice.

Acute promyelocytic leukemia (APL) is an interesting model for cancer research because of the presence of the specific PML-RARalpha fusion gene associated with the clinical response to retinoic acid differentiation therapy. To better understand and improve differentiation induction with retinoic acid, we have established a human APL-ascites model in SCID mice using the NB4 human APL cell line. NB4 (1 x 10(6) cells) were transplanted into the peritoneum (IP) of SCID mice for 1 month. NB4 ascites cells (A-NB4) appeared, which were then engrafted in SCID mice periodically for 18 passages at an interval of 3 to 4 weeks with a 100% success rate of tumor induction. The mean survival times of SCID mice transplanted with 1 x 10(6) A-NB4 cells was 21.6 +/- 2.3 days. Analysis of the biologic characteristics of ninth passage NB4 ascitic cells was performed and they were found to have the morphologic, immunologic, cytogenetic, and molecular features of cultured NB4 cells. Furthermore, A-NB4 cells were capable of differentiating when treated with all-trans retinoic acid (ATRA), as manifested by enhanced NBT reduction and CD11b expression. In vivo treatment with ATRA in SCID mice for 4 days also increased NBT reduction by A-NB4 cells. ATRA treatment significantly prolonged survival time in the group after transplantation (28.1 +/- 6.8 to 29.1 +/- 8.4 days) compared with the control (P < .001). Furthermore, treatment with adriamycin, an effective chemotherapeutic drug in APL, had a strong growth suppressive effect on A-NB4 cells. These results demonstrate that this SCID-APL (NB4 ascites cells) model is a useful preclinical system for evaluating new or known drugs in the treatment of APL.

Animals↗
PubMed1996

Expression of the protein kinase PKR in modulated by IRF-1 and is reduced in 5q- associated leukemias.

The transcription factor IRF-1 (interferon regulatory factor 1) is an activator of type I interferon and interferon-inducible genes. IRF-1 manifests tumor suppressor activity. Its overexpression results in inhibition of cell growth, and deletions of the IRF-1 gene were demonstrated in a number of human leukemias and myelodysplasias. Although the mechanism by which IRF-1 affects cell growth is unknown, it is believed that IRF-1 activates a set of genes that negatively regulate cell growth. The double-stranded RNA-dependent protein kinase (PKR), which is an interferon-inducible gene, contains a promoter element for the binding of IRF-1 and exhibits antiproliferative properties. Consequently, we investigated the role of IRF-1 in PKR expression. Here, we show that in IRF-1-deficient embryonic fibroblasts, PKR expression is reduced relative to wild-type cells. This result predicts diminished expression of PKR as a potential consequence of deletion of the IRF-1 gene in human leukemias. We show that cells of the human leukemic U937 cell line contain a deletion of one IRF-1 gene and express low levels of PKR. We demonstrate that upregulation of IRF-1 expression in U937 cells by transfection is sufficient to induce PKR expression. We also found a marked reduction in the expression of PKR in blood samples from two patients with myelodysplasias, carrying a deletion of chromosome 5q, a locus to which IRF-1 was mapped. These results show that IRF-1 activates PKR expression and suggest that loss of one allele of the IRF-1 gene is sufficient to affect PKR expression. Therefore, PKR is a strong candidate for a mediator of the tumor suppressor activity of IRF-1.

Chromosomes, Human, Pair 5↗