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Biomedical subjects

R Berger

Publications and source records attributed to R Berger.

At least 541 records · Page 30Linked to original sources
PubMed1990

Persistence of antibodies after immunization with a recombinant yeast-derived hepatitis B vaccine following two different schedules.

Four years after vaccination of healthy adults with either a recombinant yeast-derived (YDV) or plasma-derived (PDV) hepatitis B vaccine, the persistence of antibodies to hepatitis B surface antigen (anti-HBs) was examined. Subjects received three 20 micrograms doses in the deltoid region according to either a 0, 1, 6 month or 0, 1, 2 month vaccination schedule, with a 20 micrograms booster dose of YDV administered at month 12 for subjects on the second schedule. The recombinant vaccine was found to be immunologically comparable to the PDV, with anti-HBs persisting equally in both groups.

Hepatitis B Antibodies↗
PubMed1990

Simultaneous localization of cosmids and chromosome R-banding by fluorescence microscopy: application to regional mapping of human chromosome 11.

A technique for nonradioactive in situ hybridization on human metaphase chromosomes has been developed to localize human cosmid clones. The simple procedure using two fluorescent dyes (fluorescein and propidium iodide) allows the simultaneous identification of chromosomal R-bands and hybridization signal in a single screening of the slides. This technique has been used for rapid correlation of the genetic and physical map of chromosome 11q13-qter in the region of genes responsible for ataxia-telangiectasia and tuberous sclerosis.

Cell Line↗
PubMed1990

Does pH paper accurately reflect gastric pH?

The testing of gastric pH in the ICU has become the standard of care for most critically ill patients. It has been demonstrated that maintaining a gastric pH of greater than 3.5 confers protection from upper GI bleeding, while lesser pH values subject the patient to hemorrhagic risk. We compared nasogastric pH, as measured by pH electrode, to color-scaled pH paper in 16 critically ill patients hospitalized 3 to 10 days in the surgical ICU. Statistical analysis of 370 gastric specimens revealed a sensitivity of 66.7% and specificity of 94.5% when a paper pH (pH[p]) of greater than or equal to 4 was used as the therapeutic end-point. The sensitivity and specificity of the same pH(p) for clear buffered solutions were 100%. We conclude that the use of pH(p) lacks the clinical accuracy for determining the effects of therapy for the prophylaxis of stress gastritis and will lead to a significant degree of undertreatment. This lack of accuracy is not due to observer error or the quality or age of the testing paper. Our results suggest that if the measurement of gastric pH by pH(p) analysis is to be used as a guide for the prevention of stress-related hemorrhage, a more accurate method of monitoring may be warranted.

Critical Care↗
PubMed1990

Endemic Kaposi's sarcoma in human immunodeficiency virus type 1-seronegative persons: demonstration of retrovirus-like particles in cutaneous lesions.

In 1984, Greek physicians reported on the clustering of cases of Kaposi's sarcoma (KS) on the Peloponnesus peninsula. To gain more insight into its pathogenesis, we studied the seroepidemiologic and clinicopathologic characteristics of 12 Greek KS patients (eight male/four female) five of whom were residents of an endemic area on the Peloponnesus. These patients were in good general health with ages ranging from 48 to 80 years, had no clinical signs of immunodeficiency, and combined the features of both classic and epidemic KS in that they displayed not only involvement of acral areas but also widespread mucocutaneous lesions. Routine laboratory data were within normal limits; no patient had HTLV-1 and HIV-1/2 antibodies, but all patients had antibodies to several herpesviruses. The histopathology was characteristic of KS with the peculiar feature of a dense infiltrate composed predominantly of CD4+ T lymphocytes. Immunoenzymatic/morphologic studies of the KS cells were consistent with their origin from lymphatic endothelium. Outstanding ultrastructural findings were tubuloreticular structures and cylindrical confronting cisternae, structures that are indicative of an ongoing viral infection. Indeed, extensive electronmicroscopic studies resulted in the detection of retrovirus-like particles in close association to KS cells in five of 12 patients. This in situ observation opens the possibility that this retro-virus contributes to KS development.

Antibodies, Viral↗
PubMed1990

The gene for the alpha 2 chain of the human fibrillar collagen type XI (COL11A2) assigned to the short arm of chromosome 6.

A cosmid clone (CosHcol.11) containing the alpha 2(XI) collagen gene (COL11A2) has been isolated. The gene contains conserved DNA and amino-acid sequences characteristic of fibril forming collagen, which is in accordance with the classification of type XI collagen as a fibrillar collagen. The genomic clone containing the alpha 2(XI) gene has been used as probe in the Southern blot analysis of DNA from a panel of human/hamster somatic cell hybrids containing different numbers and combinations of human chromosomes. Synteny analysis revealed that only chromosome 6 showed complete concordant segregation with COL11A2. Furthermore, the gene was regionally mapped to the short arm of chromosome 6 by using a hybrid which contained only the long arm of the chromosome.

Blotting, Southern↗
PubMed1990

Chromosome mapping of the human RAS-related RAP1A, RAP1B, and RAP2 genes to chromosomes 1p12----p13, 12q14, and 13q34, respectively.

Three human cDNAs encoding new RAS-related cDNAs, designated RAP1A, RAP1B, and RAP2, have been isolated previously. The encoded proteins are highly related to RAS in the effector region and share an overall identity with RAS of approximately 50%. Using the complete cDNAs or parts thereof as probes, each RAP gene has been localized on human chromosomes by in situ hybridization. The three genes RAP1A, RAP1B, and RAP2 have been assigned to chromosome bands 1p12----p13, 12q14, and 13q34, respectively.

Autoradiography↗
PubMed1990

A reliable method for simultaneous demonstration of two antigens using a novel combination of immunogold-silver staining and immunoenzymatic labeling.

We have developed a reliable and sensitive immunohistochemical staining technique which allows the simultaneous demonstration of two different antigens expressed in or on the same cell (referred to as mixed labeling), together with the evaluation of the general histopathological appearance of the tissue. The staining procedure combines a three-step (streptavidin-biotin) immunogold-silver staining (IGSS) with a three-step immunoenzymatic labeling. For this purpose, we investigated the compatibility of IGSS with various substrates of peroxidase or alkaline phosphatase (AP). Highly reliable and discernible mixed labeling was achieved only after initial labeling with IGSS followed by AP labeling using the substrates naphthol AS-MX phosphate/Fast Blue or naphthol AS-BI phosphate/New Fuchsin, respectively. To ensure utmost specificity, we applied FITC-conjugated mouse monoclonal antibodies and rabbit anti-FITC immunoglobulins visualized by AP-labeled immunoglobulins and the respective substrate in a final step. This novel approach provides an excellent means for demonstration of immunocompetent cells and unequivocal determination of the percentage of specific cell subsets in infiltrated tissue. The advantages of this method, as compared with double immunofluorescence or double immunoenzymatic labeling, were investigated and are discussed.

Antibodies, Anti-Idiotypic↗
PubMed1990

Interferon-alpha and synthetic peptide malaria sporozoite vaccine in non-immune adults: antibody response after 40 weeks.

Adults with no known immunity to sporozoites received, i.m., at weeks 0 and 8 two single 200 micrograms doses of a peptide Plasmodium falciparum sporozoite vaccine conjugated to tetanus toxoid ((NANP)3-TT) plus placebo (group 1) or interferon-alpha (IFN-alpha) (group 2) and were followed for antibody responses at weeks 4, 12 and 40. Peak antibody responses were observed at week 12. At week 40, a greater than or equal to 4-fold increase in antibody titre to sporozoites in IFA, or to (NANP)50 in ELISA was still detectable in 6 of 12 (50%) volunteers in group 1 and in 16 of 25 (64%) in group 2. Peak antibody titres in IFA and ELISA decreased with a rate of 0.8% and 0.5% per week, respectively.

Animals↗
PubMed1990

Diagnosis of Fanconi's anemia by flow cytometry.

FA is a progressive bone marrow aplasia genetically transmitted by a recessive autosomal gene or genes. In our laboratory, cytogenetic diagnosis is based on evaluation of the chromosomal breakage of mitotic cell derived from patient blood-cell cultures and sensitized by nitrogen mustard (NM). We have observed, in parallel with this test, fluctuations of the cell cycle of PHA- stimulated peripheral blood lymphocytes from FA patients as compared with controls. FA cells treated with NM show a dramatic and significant increase in G2/M phase after 72 hr in vitro culture, compared with untreated or control cells (normal controls and non-FA patients). This test is rapid and simple, as it consists in staining cells with a DNA dye (propidium iodide), followed by a flow cytometry analysis of the cell cycle phases. Our results in twelve patients are correlated with the cytogenetic results.

Cell Cycle↗
PubMed1990

Microdissection and microcloning of human banded chromosomes.

A new microdissection and microcloning procedure of human banded chromosomes has been recently described. These microtechniques allow the construction of band-specific DNA libraries, providing a large number of DNA probes for the identification of gene sequences. These methodologies are particularly efficient to reach chromosomal regions involved in human genetic diseases including cancer.

Chromosome Banding↗
PubMed1990

Fluorescence in situ hybridization on metaphase chromosomes with biotinylated probes. In situ hybridization, biotin labeling, cosmids, gene mapping, oncogene amplification.

In situ hybridization on metaphase chromosomes have been used to localize specific nucleic acid sequences. Initially, the nucleic acid probes were labeled isotopically. Over the past few years, non isotopic techniques have considerably progressed, and are being applied to a large spectrum of biological and clinical problems.

Biotin↗
PubMed1990

A new Ph1+, bcr cell line derived from a patient with ALL-L1 gained autonomy in culture concomitant to CD23 expression.

A permanent cell line, LEF1, has been established from the cells of an adult suffering from a Philadelphia positive acute lymphoblastic leukemia. The LEF1 cell line was obtained by maintaining peripheral blood cells from the patient in culture on a fibroblast feeder; subsequently, an autonomously growing cell population, independent of that feeder layer, developed. The karyotype of the cell line, 46, t(9;22)(q34;q11), was different from the karyotype at diagnosis which had 53 chromosomes and two Philadelphia chromosomes. Furthermore, compared with the initial leukemic blasts, the immortalized cell had three differences in surface phenotype (CD23+, CD11b-, CD10-). However, molecular studies indicated that the breakpoint in the 3' part of the first intron of the BCR gene was unchanged, confirming the leukemic origin of LEF1. The cell line was shown to be Epstein-Barr virus negative.

Adult↗
PubMed1990

Retinoic acids in the treatment of acute promyelocytic leukemia.

Retinoic acid, the active metabolite of vitamin A has been shown to differentiate in vitro human leukaemic cells from patients with acute promyeolocytic leukaemia (APL). The results obtained in vivo with the 13-cis isomer of retinoic acid in combination with or after chemotherapy in four cases of APL are described. More recently Huang et al from the Shangai Institute of Haematology have treated 24 cases of APL with all-trans retinoic acid alone. They obtained 24 complete remissions. This success prompted us to treat patients with APL and a contra-indication to chemotherapy with all-trans retinoic acid. The results confirm the great efficacy of all-trans retinoic acid in APL.

Aged↗
PubMed1990

Monosomy-7 in childhood hemopoietic disorders.

Acquired pure monosomy-7 is associated with various myeloproliferative disorders (MPD), myelodysplasias (MDS), and acute myeloblastic leukemias (AML) in children and a poor prognosis. A series of 14 malignant blood disorders with pure monosomy-7 in children (eight MPD, two refractory anemia with excess of blasts, (RAEB), and four AML) is reported and compared with cases in the literature. The median age is significantly different in the patients with MPD and those with MDS or AML: 23, 80.5, and 112 months, respectively. The outcomes of MPD and RAEB are characterized by a high risk of rapid blastic transformation and resistance to polychemotherapy. Bone marrow transplantation (BMT) seems to be the best treatment, and one survival of two years in complete remission after autologous BMT in a child with AML is reported. Several myeloid cell lineages are involved in the proliferation, which partly explains the difficulties of cytologic classification and suggests that a pluripotent stem-cell is at the origin of the disease.

Adolescent↗
PubMed1990

Specific in vitro amplified probe detects the E2A gene rearrangement in the t(1;19) acute lymphoblastic leukemia.

Molecular studies have recently demonstrated that the E2A transcription factor gene was consistently located on chromosome 19 at the breakpoint of the 1;19(q23;p13) translocation, which characterizes a number of leukemias harboring a pre-B cell phenotype. Using a specific E2A gene probe spanning the DNA binding and dimerization domain obtained by PCR methodology, we were able to detect the rearrangement of the E2A gene in four cases (three patients and one cell line) of pre-B acute lymphoblastic leukemia with t(1;19) translocation.

Adult↗