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R Berger

Publications and source records attributed to R Berger.

At least 433 records · Page 24Linked to original sources
PubMed1992

A new gene, BCM, on chromosome 16 is fused to the interleukin 2 gene by a t(4;16)(q26;p13) translocation in a malignant T cell lymphoma.

A t(4;16)(q26;p13.1) chromosome translocation found in tumour cells from a patient with a T cell lymphoma was shown to rearrange the interleukin 2 gene, normally located on chromosome band 4q26, with sequences from chromosome band 16p13.1. A cDNA library of tumour cells was screened with an interleukin 2 gene-specific probe. Three clones were isolated, which consisted, from 5' to 3', of the three first exons of the interleukin 2 gene followed by a 16p13 in-frame sequence encoding 181 amino acids. A probe derived from this sequence detected a 1.2 kb transcript in various cell lines exhibiting mature B lymphoid cell features, but this was not detected in other cell lines representative of other haematopoietic lineages, or in other organs. For this reason, the novel gene was termed BCM for B cell maturation. The open reading frame of BCM normal cDNA predicted a 184 amino acid protein with a single transmembrane domain which had no homology with any protein sequence stored in data banks. Our data indicate that BCM is a new gene whose expression coincides with B cell terminal maturation.

Amino Acid Sequence↗
PubMed1992

The human fumarylacetoacetase gene: characterisation of restriction fragment length polymorphisms and identification of haplotypes in tyrosinemia type 1 and pseudodeficiency.

Deficiency of human fumarylacetoacetase (FAH) activity results in hereditary tyrosinemia type I. Using the restriction enzymes BglII, KpnI and StuI and a 1.3-kb cDNA probe for the FAH gene, we have found 6 restriction fragment length polymorphisms (RFLPs). These RFLPs were utilised in 3 tyrosinemia families in which one or both parents are carriers of both a tyrosinemia and a pseudodeficiency gene for FAH. Full information was obtained in two of these families. The polymorphisms identified 6 haplotypes. The haplotype distribution was significantly different in 32 unrelated tyrosinemia patients compared with a reference population of 100 individuals. The combined polymorphism information content was 0.77.

Alleles↗
PubMed1992

A single base change at a splice acceptor site leads to a truncated CAD protein in Urd-A mutant Chinese hamster ovary cells.

We have previously reported the isolation and characterization of mutant Chinese hamster ovary (CHO-K1) cells of the Urd-A complementation group, which require uridine for growth, are deficient in the activities of the first three enzymes of de novo UMP biosynthesis, and produce markedly reduced amounts of a truncated form of the multifunctional protein CAD, which contains these three enzyme activities. We report here that a single base change of G to A at a highly conserved RNA splice acceptor site is responsible for the phenotype of this mutant. In addition to a small amount of apparently normal CAD mRNA, this mutation causes production of two alternative forms of CAD mRNA in the mutant, one that includes the intron just prior to the mutation and one that excludes the exon just after the mutation. The affected splice site is located at the intron-exon boundary just preceding the exon that encodes the beginning of the aspartate transcarbamylase (ATCase) domain of the CAD protein. Both intron inclusion and exon exclusion during RNA processing introduce a translation stop codon upstream of the region encoding this domain, resulting in the production of the truncated CAD protein seen in the Urd-A mutant. This mutation also results in markedly decreased levels of CAD mRNA and protein in the mutant.

Amino Acid Sequence↗
PubMed1992

A single vaccination with an inactivated hepatitis A liposome vaccine induces protective antibodies after only two weeks.

In the near future an inactivated hepatitis A vaccine will be commercially available. The recommended vaccination schedule will include at least two vaccinations 1 month apart. Giving two doses of vaccine on the same day in one injection results in protection after 2-4 weeks dependent on the adjuvant used. Hepatitis A virus incorporated into liposomes proved to be a suitable formulation in term of rapid seroconversion, high level of mean antibody content and low reactogenicity.

Adult↗
PubMed1992

Reactogenicity and immunogenicity of inactivated hepatitis A vaccines.

Two inactivated hepatitis A virus (HAV) candidate vaccine strain were tested, derived from strains CLF and HM175. Neither vaccine increased liver enzymes levels and reactogenicity was similar to that observed with other alum-absorbed products. Antibody responses were dose-dependent and protection against HAV can be presumed to last for at least three years. All persons receiving 720 ELISA units (El.U) of the CLF vaccine seroconverted after one dose. For the HM175 vaccine, anti-HAV persisted until month 12 after injections at months 0 and 1, suggesting that the third dose of vaccine could be given at any time from month 6 to 12. A double dose of HM175 vaccine (1440 El.U) given as a single bolus resulted in 100% seroconversion by day 14 with a geometric mean anti-HAV level of 121 mIU/ml. This implies that rapid protection can be induced using large doses of inactivated HAV vaccine should time constraints dictate such an approach.

Adult↗
PubMed1992

The genes for MHC class II regulatory factors RFX1 and RFX2 are located on the short arm of chromosome 19.

RFX1 is a transacting DNA-binding regulatory factor involved in the control of MHC class II gene expression. RFX2 is a structurally very similar protein with identical DNA binding features. A member of the family of RFX factors is affected in an autosomal recessive disease, MHC class II deficient combined immunodeficiency (CID), caused by a defect in a trans-acting regulatory factor controlling MHC class II gene expression. In situ hybridization with 3H-labeled RFX1 cDNA has allowed us to identify two distinct targets on the short arm of chromosome 19 (19p13.1 and 19p13.2-p13.3). With the use of biotinylated genomic cosmid clones specific for RFX1 and RFX2, respectively, it was then possible to localize RFX1 at 19p13.1 and RFX2 at 19p13.2-p13.3. These two regulatory genes are thus assigned to a region of high gene density and RFX1 is close to another DNA-binding factor, LYL1.

Chromosome Mapping↗
PubMed1992

A cluster of expressed zinc finger protein genes in the pericentromeric region of human chromosome 10.

Three members of the human zinc finger Krüppel family, ZNF11/KOX2, ZNF22/KOX15, and ZNF25/KOX19, have been regionally localized to the pericentromeric region of chromosome 10 by in situ chromosomal hybridization and somatic cell hybrid analysis. ZNF25/KOX19 is located centromeric to a breakpoint in chromosome band 10q11.2 in the chromosome region 10p11.2-q11.2, whereas ZNF22/KOX15 maps distal to it in band 10q11.2. Sequences hybridizing to the KOX2 probe are found at two loci, ZNF11A and ZNF11B, that map proximal and distal to the 10q11.2 breakpoint, respectively. The two ZNF11 loci probably represent two related sequences in 10p11.2-q11.2. This cluster of ZNF/KOX genes is of particular interest since the loci for multiple endocrine neoplasia type 2A and 2B (MEN2A and MEN2B) syndromes have been assigned to this region by linkage analysis.

Centromere↗
PubMed1992

Sequence-tagged sites (STSs) for a set of mapped markers on chromosome 21.

Sequence tagged sites (STSs) have been proposed as a "common language" for comparing physical and genetic maps of the human genome produced by a variety of techniques. We have produced 44 STSs from 38 mapped loci on human chromosome 21. The STSs represent most of the loci designated as genetic reference or ordered physical framework markers, along with a number of others chosen to span all regions of 21q. Of the STSs, 12 are from gene segments, including 4 from exons of the APP gene encoding the amyloid beta protein precursor, and 32 mark anonymous DNA loci. These STSs make each of the corresponding loci readily accessible to the research community without the need for exchange of clones. These sites also represent multiple start points for the isolation of YAC clones that should permit overlapping the entire chromosome 21 long arm as cloned DNA.

Animals↗
PubMed1992

Effects of yohimbine on heart rate variability in panic disorder patients and normal controls: a study of power spectral analysis of heart rate.

We studied the effects of yohimbine on heart rate (HR) variability in 13 normal controls and 13 patients with panic disorder. Yohimbine produced a significant increase in SD of HR in standing posture in both patients (p = 0.01) and normal controls (p = 0.025). Panic disorder patients had a significant increase in standing absolute midfrequency (MF) power (0.07-0.15 Hz) after administration of yohimbine (p = 0.002). The ratio of post- to preyohimbine standing MF power (0.07-0.15 Hz) during standing was significantly higher in patients as compared with controls (2.3 +/- 1.08 vs. 1.33 +/- 0.38; p = 0.01), which suggests an increased responsivity of panic disorder patients to the adrenergic effects of yohimbine.

Adult↗
PubMed1992

Isolation of human immunodeficiency virus type 1 from human epidermis: virus replication and transmission studies.

For a better understanding of the pathogenetic events operative in the cutaneous manifestations of human immunodeficiency virus type 1 (HIV-1) disease, we investigated whether epidermal cells (EC) from HIV-1-seronegative persons can be infected with HIV-1 and, vice versa, whether HIV-1 can be rescued from the epidermis of HIV-1-infected individuals. In a series of three experiments, we consistently found that exposure of EC from HIV-1-seronegative donors to HIV-1 led to viral replication in these cells as evidenced by the detection of HIV-1 p24 in culture fluids. Because EC had been substantially enriched for Langerhans cells (LC) before being exposed to HIV-1, it is reasonable to assume that these CD1a+/CD4+/MHC class II+ antigen-presenting cells of the epidermis represented the actual targets of infection. This assumption is further strengthened by the observation that T cell-depleted cell suspensions from Langerhans cell histiocytosis (LCH) lesions could be productively infected with HIV-1. Conversely, co-culture of epidermal sheets from HIV-1-seropositive individuals with mononuclear phagocytes (MNP) from HIV-1-seronegative donors resulted, after 3 to 5 weeks, in the detection of HIV-1 p24 in 12 of 23 cases. Immunocytochemical analysis, using a monoclonal antibody specific for p24, revealed the presence of HIV-1 in adherent MNP in three cocultures tested. In addition, cellular DNA from these cultures showed strong signals when hybridized to a HIV-1-specific DNA probe. The further finding that two isolates examined exhibited different restriction enzyme patterns indicates that they are separate entities rather than contaminants. Transmission of these isolates to MNP, B- or T-cell lines resulted in cultures strongly positive for p24 and, in the case of H9 cells, for viral particles as detected by electron microscopy. Our results therefore strongly suggest that EC not only can serve as targets for HIV-1, but also can allow efficient virus replication and transmit HIV-1 to various cell types of the hematopoietic lineage.

Cell Line↗
PubMed1992

Mutations of the P53 gene in acute myeloid leukaemia.

In a previous report we found point mutations in exons 5-8 of the P53 gene in five of 46 patients with acute myeloid leukaemia (AML), with a predominance of mutations in the 10 patients with 17p monosomy. In this report we extended our findings studying such mutations in 66 unselected additional cases of AML, using polymerase chain reaction single strand conformation polymorphism (SSCP) analysis and nucleotide sequencing. Three of the 66 new cases had a point mutation, leading to a change in one encoded amino acid. Thus, eight of the 112 AML studied had P53 mutations in exons 5-8, suggesting that the incidence of P53 mutation is relatively low in AML. A predominance of mutations in exon 8 (5/8) was found. Six of the eight patients with mutations were older than 60 years of age, and all eight cases had a short survival. All seven mutated cases karyotyped showed complex cytogenetic findings, especially monosomy 5 and/or 7, thus questioning the pathogenic importance of P53 mutations in a context of multiple genetic abnormalities. However, five of them also had 17p monosomy, and in the remaining two cases SSCP and sequence analysis also suggested loss of the normal P53 allele. This supported a role for the P53 gene mutations in leukaemogenesis in the relatively small number of AML patients in whom they were found, through loss of tumour suppressive activity of both normal P53 alleles, as reported in solid tumours.

Acute Disease↗
PubMed1992

Diagnosis and treatment control of choroidal melanomas--the role of B-scan and Doppler-technique.

B-scan guided pulsed Doppler ultrasonography was applied in 62 patients with unilateral malignant melanoma. Prior to radiotherapy Doppler frequency shifts were detected in all but one neoplasm. The average systolic tumour blood flow velocity was recorded as 18.8 +/- 7.6 cm/s. Frequency shifts after radiotherapy are described. Probably the methods will find a place in the evaluation of indeterminate fundus lesions and in the follow-up of irradiated ocular melanomas.

Blood Flow Velocity↗
PubMed1992

Plasma Met-enkephalin and catecholamine responses to intense exercise in humans.

Native and cryptic Met-enkephalin and catecholamines are coreleased in response to stress. However, it is not known whether Met-enkephalin and catecholamines exhibit concurrent temporal relationships in response to exercise. The purpose of this investigation was to examine the corelease of catecholamines and Met-enkephalin in endurance-trained (n = 6) and untrained (n = 6) male subjects during a 6-min bout of exercise: 4 min at 70% of maximal O2 uptake (VO2max) followed by 2 min at 120% VO2max. Peak catecholamine levels were found at 1 min of recovery. In trained subjects, native Met-enkephalin peaked during exercise at 70% VO2max, declined during exercise at 120% VO2max, and returned to basal levels by 1 min of recovery. In the untrained subjects, native Met-enkephalin peaked at 120% VO2max (6 min) and returned to baseline by 5 min of recovery. In both groups, cryptic Met-enkephalin peaked at 70% VO2max and returned to basal levels during exercise at 120% VO2max. These data demonstrate that during exercise there is a temporal dissociation in plasma levels of Met-enkephalin and catecholamines.

Adult↗