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G Ott

Publications and source records attributed to G Ott.

At least 19 recordsLinked to original sources
PubMed1996

NMR evidence for helix geometry modifications by a G-U wobble base pair in the acceptor arm of E. coli tRNA(Ala).

A ribooligonucleotide duplex representing the acceptor stem of E. coli RNA(Ala) with a G3-U70 wobble base pair, which is the main identity element for the recognition by the alanine-tRNA synthetase, has been characterized by 2D-NMR, as having two sequence variants with a regular Watson-Crick G3-C70 and an I3-U70 wobble pair, respectively. As compared to a regular A-RNA, the G-U base pair gives rise to variations of the local helix geometry which are reflected in distinct local chemical shift changes. Structural differences between the duplex possessing an I3-U70 base pair and the wild-type G3-U70 sequence have also been found. The nucleotides in the ubiquitous single-stranded NCCA terminus display a surprisingly high degree of stacking order, especially between A73, C74, and C75.

Base Composition↗
PubMed1996

Common Epstein-Barr virus (EBV) type-1 variant strains in both malignant and benign EBV-associated disorders.

In the present study, Epstein-Barr virus (EBV) isolates from 18 malignant tumors (angioimmunoblastic lymphadenopathy [AILD], n = 4; Hodgkin's disease [HD], n = 3; pleomorphic T-cell non-Hodgkin's lymphoma [T-NHL], n = 1; B-cell non-Hodgkin's lymphoma [B-NHL], n = 8; gastric carcinoma, n = 2) as well as from 10 tonsils of EBV-seropositive children and from peripheral blood mononuclear cells of 12 children with uncomplicated infectious mononucleosis (IM) and of a boy with severe chronic active EBV infection were genotyped in the EBV nuclear antigen-2 (EBNA-2) gene. A total of 40 of 41 isolates harbored EBV type 1; in 1 specimen (tonsil), only EBV type 2 was found. Further molecular characterization of EBV type-1 wild-type isolates in the EBNA-2 gene and in the 40-kb distant EBV-encoded small RNAs (EBER) region showed that different groups of stable EBV type-1 variant strains exist in vivo both in benign and malignant lymphatic tissue. Group 1 is composed of EBV type-1 isolates (B-NHL, n = 3; T-NHL, n = 1; HD, n = 1; IM, n = 4) that showed a B95-8-like DNA sequence pattern in both viral genes. Group 2 isolates (HD, n = 1; AILD, n = B-NHL, n = 1; tonsils of EBV-seropositive children, n = 9; IM, n = 20 showed a nucleotide change at position 49095 in the EBNA-2 gene, leading to an amino acid substitution (Pro-->Ser), and EBV type-2 sequences in the EBER region. EBV type-1 isolates that fall into group 3 (AILD, n = 3; HD, n = 1; B-NHL, n = 4; gastric carcinoma, n = 2; IM, n = 6; severe chronic active EBV infection, n = 1) were characterized by typical nucleotide changes and a 3-bp insertion (CTC; extra Leu residue) in the EBNA-2 gene and an EBV type-2-specific sequence pattern in the EBER region. These EBV type-1 variant strains may represent the most prevalent circulating EBV type-1 strains in the exposed population and seem not to be restricted to a certain EBV-associated disease or tumor type. However, analysis of more EBV isolates from benign and malignant lesions must show whether more EBV type-1 substrains exist in vivo.

Base Sequence↗
PubMed1996

bcl-1 rearrangement and cyclin D1 protein expression in mantle cell lymphoma.

Centrocytic lymphoma, or mantle cell lymphoma (MCL), is characterized by a chromosomal translocation t(11;14) (q13;q32) involving the bcl-1 locus on chromosome 11. Cyclin D1 is a cell-cycle regulatory protein essential for G1-S transition and has been identified as a potential transforming gene affected by the translocation. In this study, 32 cases of MCL were analysed for the bcl-1 rearrangement and cyclin D1 protein expression. In 17 cases, a rearrangement at the major translocation cluster of bcl-1 could be detected. Twenty-four cases exhibited nuclear cyclin D1 expression that was not detectable in other B-cell lymphomas (n = 40) or in normal B-cells. In nine MCL samples, cyclin D1 was expressed without a detectable bcl-1 rearrangement. The detection of a t(11;14) by means of classical cytogenetics in one of these cases, however, may suggest that this discrepancy could be due to chromosomal breakages outside the typical translocation cluster region. In two cases, a bcl-1 rearrangement was not accompanied by cyclin D1 expression. This study provides further evidence that cyclin D1 is involved in the pathogenesis of MCL and can be exploited as a diagnostic marker in the differential diagnosis of B-cell lymphomas and in the identification of MCL.

Base Sequence↗
PubMed1996

Vascular patterns in reactive and malignant lymphadenopathy.

A total of 130 superficial lymph nodes were evaluated using color Doppler flow imaging (CDFI) in order to differentiate benign from malignant lymphadenopathy. The patterns of intranodal flow signals detected at standardized conditions by CDFI were classified using eight self-defined criteria and were correlated with the histopathological or clinical diagnosis. Nonparametric discriminant analysis showed that four vascular were suspicious of malignancy: (a) avascular areas, (b) displacement of intranodal vessels, (c) accessory peripheral vessels and (d) aberrant course of central vessels. Of the neoplastic lymph nodes (n = 73), 96% showed at least one pathological vascular pattern. Malignancy could be excluded in 95% of 57 reactive lymph nodes using these four criteria. Most reactive lymph nodes in contrast demonstrated a vascular hilus and/or vessels running at the long axis of the lymph node with branches to the cortex. There was a diagnostic accuracy of 41-82% in the additionally evaluated sonomorphological (size, shape, echogenicity) and Doppler (increased Pourcelot's or pulsatility indices) criteria. The definitive interpretation of the promising results of this retrospective study requires confirmation of examiner independency as well as a prospective evaluation.

Adolescent↗
PubMed1996

Occurrence of multiple lymphoepithelioma-like carcinomas and MALT-type lymphoma in the stomach: detection of EBV in carcinomas but not in lymphoma.

A multifocal lymphoepithelioma-like carcinoma and a low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT-type) were found simultaneously in the stomach of a 65-year-old patient. Carcinoma and lymphoma were intimately associated forming complexes resembling lymphoepithelial lesions at the primary gastric site and in lymph node metastases. The two tumours had developed on a background of severe chronic-atrophic gastritis of the mucosa of antrum and fundus. Autoantibodies to normal gastric glandular tissue could be demonstrated in the patient's sera. Using non-radioactive in situ hybridization (ISH), Epstein-Barr virus (EBV) sequences were detected in virtually all carcinoma cells but neither in the non-neoplastic mucosa nor in the lymphoma. These findings suggest that a focal EBV infection occurred early in the development of the carcinoma followed by a subsequent clonal expansion of the EBV-containing tumour cells. A neoplastic transformation in MALT-type lymphoma is not EBV-related but might be triggered by altered immune mechanisms.

Aged↗
PubMed1996

Lack of association between atopy and the Ile181Leu variant of the beta-subunit of the high-affinity immunoglobulin E receptor.

A previous study has reported a strong association of a variant (Ile181Leu) of the beta-subunit of the high-affinity IgE receptor (Fc epsilon RI-beta) with allergic asthma bronchiale in a random patient sample. Based on their results the authors concluded that Fc epsilon RI-beta may be the maternally inherited, atopy-causing locus. We have investigated 40 unrelated atopic patients, 30 with allergic asthma and 10 with atopic dermatitis or allergic rhinoconjunctivitis along with some of their relatives for the presence of Ile181Leu by nucleic acid sequence analysis and/or hybridization with mutation-specific oligonucleotide probes. None of the probands showed this mutation suggesting that its association with atopy may be restricted to certain populations or occur at lower frequency than reported.

Adolescent↗
PubMed1996

Pulmonary sarcoidosis: patterns of cytokine release in vitro.

This study was designed to investigate the ability of bronchoalveolar and blood mononuclear cells to produce inflammatory mediators in vitro in pulmonary sarcoidosis. Seventeen patients with pulmonary sarcoidosis (stage I n = 8; stage II/III n = 9) and 10 normal controls were investigated. Bronchoalveolar and peripheral blood mononuclear cells were cultured in serum-free medium, without stimulant, for 24 h, and the supernatants analysed for concentrations of interleukin (IL)-1 beta (IL-1 beta), IL-2, IL-6, tumour necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-gamma) and neopterin. Bronchoalveolar lavage cells (BALC) of sarcoid patients released significantly higher amounts of TNF-alpha, IL-6, IFN-gamma and neopterin in comparison to normal controls. When smokers were excluded, there was also an increased release of IL-1 beta and GM-CSF. In the sarcoid group, the levels of IL-1 beta, IL-6, TNF-alpha and GM-CSF showed highly significant correlations between each other, but not with IL-2, IFN-gamma or neopterin. Sarcoid patients whose BALC released more TNF-alpha or GM-CSF had higher percentage counts of alveolar macrophages but fewer lavage lymphocytes. In sarcoid patients, peripheral blood mononuclear cells (PBMNC) also released higher amounts of IL-1 beta, TNF-alpha, IL-6 and GM-CSF but less neopterin than normal controls. Patients whose PBMNC produced more IL-1 beta, IL-6 and GM-CSF had higher absolute and relative lavage neutrophil counts. No relationships were observed between cytokine release and radiographic or physiological markers of disease severity. We conclude from this study that sarcoid inflammation is associated with an increased and concerted release of monocyte/macrophage-derived cytokines not only in the lung but also in the peripheral blood. We speculate that the lymphokines, IFN-gamma and IL-2, are not the primary triggers.

Adult↗
PubMed1996

Differentiation of low grade non-Hodgkin's lymphoma by digital image processing.

OBJECTIVE: To identify different types of low grade B-cell non-Hodgkin's lymphoma (NHL) classified according to the Revised European American Lymphoma and Kiel classification systems by means of digital image processing. STUDY DESIGN: Seventy-four touch imprints were scanned and analyzed. To compare common but intricate DNA stain with a routinely used panoptical dye, all lymphoma specimens had been stained by the Romanowsky-Giemsa method and 48 touch imprints redyed with Feulgen-Azure A. In both cases 30 features derived from size, and chromatin texture of each nucleus were evaluated. RESULTS: Feulgen-stained touch imprints showed a 59% average probability of correct identification. The division of mantle cell lymphoma and chronic lymphocytic leukemia was difficult. In contrast, it was possible to distinguish all different types of lymphomas investigated if Romanowsky-Giemsa stain was used. Correct diagnoses were achieved for mantle cell lymphoma in 87.5%, follicle center cell lymphoma in 78%, chromic lymphocytic leukemia in 78%, immunocytoma in 75% and marginal zone B-cell lymphoma in 80%. CONCLUSION: The application of texture analysis is feasible in the classification of NHL.

Azure Stains↗
PubMed1995

[Pathology and pathogenesis of extranodal lymphomas in the gastrointestinal tract].

Primary extranodal lymphomas of the stomach represent a fascinating object of investigation for clinicians and basic scientists. Possibly multifocal clonal populations of lymphocytes develop, which progress to highly malignant lymphomas over many years, starting from a previous reactive disease, commonly an Helicobacter-pylori-associated chronic gastritis or an organ related autoimmune disease in case of other sites of MALT lymphomas. In early stages of clonally restrained NHL of low malignancy of the MALT type a complete tumor regression can be achieved by elimination of the triggering agent Helicobacter pylori. At least a long standing remission is expected. The site and the frequency of relapse cannot be predicted until now. Basic requirement for the treatment by eradication of Helicobacter is the doubtless and well documented diagnosis of a low malignant NHL, based on immunohistological++ and molecular biologic findings, to prove scientifically the efficacy of this treatment. This will establish the basis to assess the stage and the grade of a primary gastric lymphoma in the future.

Gastritis↗
PubMed1995

MF59. Design and evaluation of a safe and potent adjuvant for human vaccines.

MF59 is a safe, practical, and potent adjuvant for use with human vaccines. The formulation is easily manufactured, may be sterilized by filtration, and is both compatible and efficacious with all antigens tested to date. MF59 has been shown to be a potent stimulator of cellular and humoral responses to subunit antigens in both animal models and clinical studies. Toxicology studies in animal models and Phase I-III studies in humans have demonstrated the safety of MF59 with HSV, HIV, and influenza vaccines.

Adjuvants, Immunologic↗
PubMed1995

Enhancement of humoral response against human influenza vaccine with the simple submicron oil/water emulsion adjuvant MF59.

Human influenza subunit vaccines are not fully protective in either the very young or elderly populations where risk is greatest. The use of an adjuvant to enhance antibody titer is an attractive option to increase vaccine efficacy. A series of squalene/H2O emulsions stabilized either by the amphipathic muramyl peptide MTP-PE (sodium N-acetyl-muramyl-L-alanyl-D-isoglutaminyl-L-alanyl-2-(1',2'-dipalmitoyl- sn- glycero-3'phospho) ethylamide) or by mixtures of the sorbitan oleate surfactants Tween 80 and Span 85 have been tested as adjuvants with influenza vaccine. Combination of influenza vaccine with the Tween/Span stabilized emulsions has resulted in significantly higher antibody titers to vaccine in an extensive series of naive animal models. The use of submicron emulsion droplets is significant in determination of adjuvant activity while the presence of the muramyl peptide is not required for adjuvant activity. The 200-300 nm diameter emulsion formulation MF59 containing only the low toxicity components squalene, Tween 80 and Span 85 has been shown to enhance titers from 5 to 250 times that achievable with vaccine alone.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1995

Localized gastric non-Hodgkin's lymphoma of high-grade malignancy in patients with pre-existing chronic lymphocytic leukemia or immunocytoma.

Analyses for clonality in cases of Richter's syndrome have provided evidence for a clonal evolution of high-grade lymphoma in most patients, while in others an independent cellular clone seems to exist in the secondary neoplasm. Richter's syndrome with an isolated high-grade lymphoma of the stomach has been rarely reported in patients with pre-existing B cell chronic lymphocytic leukemia (CLL). We investigated four cases of CLL or lymphoplasmacytoid immunocytoma (LPIC) with development of a localized high-grade B cell lymphoma in the stomach. Southern blotting showed different rearrangements of the immunoglobulin light and heavy chain genes in the tumor cells of the low-grade lymphoma and the gastric tumor in two cases. Comparison of the DNA sequences of the CDR3 region of the immunoglobulin genes revealed different clones in another case. By means of chromosomal in situ hybridization, trisomy 3 was detected in two cases of high-grade lymphoma of the stomach, but not in the cells of the associated low-grade tumor. Our findings indicate that high-grade non-Hodgkin's lymphomas arising localized in the stomach of patients with CLL or immunocytoma are not clonally related to the pre-existing low-grade lymphoma and, therefore indeed, present true secondary neoplasms.

Aged↗
PubMed1995

[Smoking cessation at work exemplified by "action blanca casa", a project for smoking cessation in the D. Swarovski & Co., Wattens, firm].

Recent studies about the efficacy of smoking cessation programs in the workplace have brought up to common difficulties. Only long-term-programs show remarkable effects on smoking habits of the workers. Presenting ongoing long-term strategies for open discussion can improve the design of more powerful cessation programs in the future. Our program as an important part of modern "human resources management" is demonstrated and the results after 18 months are discussed.

Adult↗
PubMed1995

Interaction of mitochondrial elongation factors Tu.Ts with aminoacyl-tRNA.

The interaction between the bovine mitochondrial translational elongation factor Tu.Ts complex (EF-Tu.Tsmt) and aminoacyl-tRNA has been investigated using a nuclease protection assay and fluorescence enhancement of [AEDANS-s2C]Tyr-tRNA(Tyr). The equilibrium dissociation constant, Kd, for the EF-Tu.Tsmt:GTP:E. coli Phe-tRNA complex is approximately 50 nM. A similar binding constant (30 nM) is obtained using bovine mitochondrial Phe-tRNA. The equilibrium binding constant for the EF-Tu.Tsmt:GTP:yeast [AEDANS-s2C]Tyr-tRNA(Tyr) complex is approximately 4 nM when determined using the fluorescence enhancement assay.

Animals↗
PubMed1994

[Immunoproliferative small intestinal disease (IPSID): an unusual form of gastrointestinal lymphoma].

Worsening of long-lasting diarrhea, abdominal discomfort and weight loss were main symptoms in a 27-year-old Moroccan woman who had lived in Germany for 18 years. Pseudomonas, salmonella and lamblia cysts were found in stools. Histological examination of the gastrointestinal tract showed immunoproliferative small intestinal disease (IPSID), characterized by atrophy of the villi and lymphoplasmocytic infiltrates. alpha 1-heavy chains were found immunohistologically in the biopsy specimen, but not in serum, urine or jejunal juice. HLA-typing gave evidence of A9. Antibiotic treatment was successful for almost one year. Clinical, histological and immunological diagnosis of IPSID in an African woman living for nearly 20 years in Europe shows that, besides environmental factors, genetic disposition is an essential factor in the development of IPSID.

Adult↗
PubMed1994

HLA-DR mismatching correlates with early cardiac allograft rejection, incidence, and graft survival when high-confidence-level serological DR typing is used.

To determine if cardiac allograft outcome is improved among patients with fewer HLA-DR mismatches with their donors, we studied 132 recipients of a primary cardiac allograft who were transplanted between December 1985 and December 1991. These recipients and their donors all had high-confidence-level serological HLA-DR typing, previously shown to correlate highly with DNA DR typing. Patients were divided in two groups based on the HLA-DR mismatch with their donors. Group I consisted of 78 patients with 1 or zero DR mismatch and group II of 54 patients with 2 DR mismatches. Allograft outcome measurements included incidence of moderate rejection, incidence of allograft vasculopathy at 12 months, cardiac function measured as left ventricular ejection fraction (LVEF) and cardiac index (CI), and actuarial graft survival up to 7 years. Groups I and group II were not different with regard to recipient age, donor age, ischemia time, pulmonary vascular resistance, sex, or PRA greater than 0%. Group II had a higher incidence of moderate rejection on the first-week biopsy (47% vs. 25%, P = 0.019), and during the first month (84% vs. 58%, P = 0.006), but no difference was found in frequency of rejection from months 2 to 12. LVEF was not different in the groups at any point. CI was better in group I at 12 months (2.76 vs. 2.5, P = 0.03). No statistically significant difference was found in incidence of allograft vasculopathy (17% vs. 26%, P = 0.204). Actual graft survival at 1 year was better for group I (91% vs. 74%, P = 0.008), and actuarial graft survival at 6 years also favored group I (76% vs. 56%, P = 0.04). Using high-confidence-level serological HLA-DR typing assignments we demonstrated that HLA-DR mismatching correlates highly with cardiac allograft outcome. Implications are that heart transplant survival could be improved if prospective matching were feasible and prioritized or if immunosuppression were tailored to the HLA-DR match.

Coronary Circulation↗
PubMed1994

Interphase cytogenetics of glioblastoma and gliosarcoma.

Interphase cytogenetics, i.e., in situ hybridization using probes to chromosome-specific DNA, enables histological identification of cells bearing numerical chromosome aberrations and cytogenetic analysis of composite tumors. We studied routinely processed tissues from seven glioblastomas and three gliosarcomas using biotinylated probes to pericentromeric alpha-satellite sequences on chromosomes 10, 17 and X. By applying various pretreatment protocols, an evaluable compromise between morphology and signal intensity was obtained in most cases. Compared to vascular cells with normal chromosomal counts, a significant subpopulation of glioblastoma cells showed monosomy 10 (four of five cases), monosomy 17 (one of seven cases) and loss of one X chromosome (one of seven cases). All monosomy 10 cases comprised additional areas where two copies of chromosome 10 were retained. Among the gliosarcomas, both the glioma and the sarcoma portion showed monosomy 10 in one case and monosomy 17 in another case. In contrast, in the third case of gliosarcoma, monosomy 10 was found only in the glioma portion, whereas a gain of chromosome X was observed in the sarcoma portion. We conclude that: (1) numerical chromosome aberrations can be detected in routinely processed brain tumor biopsy specimens using interphase cytogenetics, making retrospective studies feasible; (2) glioblastomas show intratumoral cytogenetic heterogeneity with formation of monoclonal cell clusters; and (3) sarcoma and glioma elements in gliosarcomas may exhibit the same or different numerical chromosome aberrations, suggesting various histogenetic pathways of the sarcoma-like portion.

Adult↗