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Biomedical subjects

G Horvath

Publications and source records attributed to G Horvath.

At least 73 records · Page 4Linked to original sources
PubMed1991

Expression of Epstein-Barr virus nuclear antigen 2 in insect cells from a baculovirus vector.

The open reading frame encoding the Epstein-Barr virus nuclear antigen 2 (EBNA-2) has been expressed in a recombinant baculovirus vector. The resulting product migrates with the same apparent molecular weight as EBNA-2 from latently infected or converted B cell lines. Rabbit antisera derived from the innoculation of this material immunoprecipitated EBNA-2 from cell extracts of EBV-containing cells. The high level of protein expression obtained in insect cells stands in sharp contrast to that seen in a number of mammalian cell lines using a variety of promoters including the endogenous EBNA-2 promoter, the Moloney MuLV LTR, the murine immunoglobulin heavy chain promoter, the human cytomegalovirus immediate early promoter, and the adenovirus major late promoter.

Animals↗
PubMed1990

Highly active and selective anticoagulants: D-Phe-Pro-Arg-H, a free tripeptide aldehyde prone to spontaneous inactivation, and its stable N-methyl derivative, D-MePhe-Pro-Arg-H.

D-Phe-Pro-Arg-H sulfate (GYKI-14166) is a highly active and selective inhibitor of thrombin both in vitro and in vivo. Recent studies on the stability of D-Phe-Pro-Arg-H in neutral aqueous solution at higher temperature have revealed that it is transformed into inactive 5,6,8,9,10,10a-hexahydro-2-(3'- guanidinopropyl)-5-benzyl-6-oxo- imidazo[1,2-a]pyrrolo[2,1-c]pyrazine. No such inactivation could be observed with Boc-D-Phe-Pro-Arg-H (GYKI-14451), but this compound was far less specific than the free peptide as it inhibited thrombin and, for instance, plasmin equally well. Assuming that the transformation of free tripeptide aldehyde, mentioned above, can only be initiated by a primary amino terminus, the N-alkyl derivatives of D-Phe-Pro-Arg-H were prepared. Of the new analogues, D-MePhe-Pro-Arg-H (GYKI-14766) proved to be as highly active and selective anticoagulant as its parent compound and was not inactivated by transformation into a heterocyclic compound.

Animals↗
PubMed1990

CT demonstration of fistulae in patients with gynecologic neoplasms.

Ten women treated for gynecologic neoplasms (8 cervical carcinomas, one vaginal and one endometrial carcinoma) were found at computed tomography (CT) to have a fistula although only 5 patients had symptoms that could be related to a fistula. Five women had vesico-vaginal fistulae, 2 recto-vaginal, 2 entero-cervical and one a vulvo-pubical fistula. We regard CT as the radiologic method of choice in diagnosing gynecologic fistulae.

Adult↗
PubMed1990

Influence of "nuclear" estrogen receptor content on prognosis of early stage carcinoma of the uterine body. A short-time follow-up.

Sixty-five patients with Stage I and II endometrial carcinoma were investigated. After a short-time follow-up (17-24 months) significant differences in frequency of relapses were observed between patients with tumors containing low amounts of estrogen receptor (ER less than 60 fmol/mg DNA) in the nuclear pellet, and those with tumors containing greater than 60 fmol ER/mg DNA (p = 0.01). Other prognostic factors showed no differences in frequency of relapses. In this small patient material with a short-time follow-up we therefore suggest that ER in the nuclear pellet may be an important prognostic factor.

Adenocarcinoma↗
PubMed1990

Predicting esthetics of laminate veneers without tooth preparation.

High expectations may contribute to stress in the patient and dentist during dental treatment. Esthetic and restorative results can be predicted for laminate veneers by using a powder blower and a liquid dispenser preoperatively to form self-cured resin veneers. Trial veneers are formed in a precision "salt and pepper" technique that conserves materials and time. The trial veneers are placed, without tooth preparation, on the treatment site so that the patient can preview the planned treatment and so that the dentist can explain proposed treatment in a reversible procedure. This may circumvent misunderstandings between dentist and patient and allow the consideration of alternate treatment plans.

Acrylic Resins↗
PubMed1989

Effect of mild postnatal hypoxia and L-dopa administration on dopamine concentration in striata of the newborn rat and long term sequelae on dopamine turnover.

Mild chronic postnatal hypoxia induces a long-lasting increase of DA release from striatal slices in rats. The effect of mild hypoxia on DA and DOPAC concentrations were examined in striata of newborn and adult rats. The short-lasting hypoxia (1 h, pO2 of inspired air was 11.3 kPa) did not change the concentrations of DA and DOPAC neither in newborn nor in adult rats. The long-lasting mild hypoxia (10 h or 17 h) increased the concentrations of DA, decreased that of DOPAC and decreased the turnover of DA turnover. Neither the DA concentration nor DA turnover were altered in striata of adult rats after an exposure to the mild chronic postnatal hypoxia.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1989

Effect of pyritinol on the dopaminergic system and behavioural outcome in an animal model of mild chronic postnatal hypoxia.

Rats after mild chronic postnatal hypoxia always show late sequelae of behaviour and long-term alterations of neurotransmitter release from striatal slices. It was to test preventive or therapeutic actions of drugs using the model of mild chronic postnatal hypoxia of the rat. Pyritinol prevented the learning deficit due to hypoxia and decreases the potassium stimulated DA release from striatal slices. The experiments underline the high plasticity of the CNS during the neonatal period and stress the necessity of early therapy of perinatal brain damage.

Animals↗
PubMed1989

Estrogen receptor content in nuclear pellet from adenocarcinoma corporis uteri biopsies.

Ninety-one patients with Stage I and II endometrial carcinoma were investigated. Biopsy material obtained prior to primary treatment was analyzed for contents of estrogen (ER) and progesterone (PgR) receptors, and the values of these were related to the degree of malignancy. ER content in the nuclear pellet was decreased at increased tumor anaplasia.

Adenocarcinoma↗
PubMed1988

Alternate structures and stabilities of c-myc RNA in a bursal lymphoma cell line.

A bursal lymphoma cell line, BK25, had been shown to be haploid at the c-myc locus and to have undergone an alteration of chromatin structure upstream from the c-myc coding region. In BK25 DNA at least the 3' half of an ALV provirus is integrated 160bp upstream from exon 2. As a result of this integration event, the first and second exons are separated by at least 17 kb. Approximately 90% of c-myc transcription begins in the promoter of the ALV proviral long terminal repeat (LTR) and this mRNA has a half-life of approximately 25 minutes in actinomycin D chase experiments. Approximately 10% of c-myc transcription initiates at the normal promoter of c-myc. The latter message has an unusually long half-life of greater than 100 minutes. By contrast, in MSB-1 cells, which lack any c-myc rearrangements, transcription begins at the normal promoter in exon 1 and c-myc RNA has a half-life of approximately 15 minutes. These results suggest that factors in addition to the structure of the 5' end of chicken c-myc RNA determine its stability in vivo.

Animals↗
PubMed1987

Comparison of estrogen receptor enzyme immunoassay and a radioligand binding assay (isoelectric focusing) in adenocarcinoma of the uterine body.

Thirty-two samples from adenocarcinoma of the uterine body were analyzed for estrogen receptor (ER). ER was measured with two techniques: isoelectric focusing (IF) in polyacrylamide gels and enzyme immuno assay (EIA) with monoclonal antibodies. When comparing, a very good correlation between IF and EIA was found. ER recovery was, however, increased twice when using the latter technique. The advantages of EIA in terms of its rapidity and simplicity should be considered against its, at present, greater expenses compared with methods based on radiolabeled ligands.

Adenocarcinoma↗
PubMed1986

Doxorubicin-cisplatin combination chemotherapy for recurrent carcinoma of the cervix.

A total of 31 patients with recurring or metastasizing squamous cell carcinoma of the cervix were treated with doxorubicin and cisplatin. Sixteen patients (Group 1) had previously been treated with external irradiation and two intracavitary radium applications, and 15 patients (Group 2) had been treated with radiotherapy plus chemotherapy with bleomycin plus mitomycin, peplomycin, or melphalan. The overall frequency of response was approximately 16% (five of 31 patients). In Group 1, two of 16 patients had complete remission for 14+ and 28 months, and survival for 36+ and 45+ months. One of 16 patients had partial remission for 8 months, and survival for 16+ months. In Group 2, two of 15 patients achieved partial remission for 16 and 18 months, and survival for 28 and 35 months. No serious side effects were noted in the two groups.

Adult↗
PubMed1985

On the difference between colonic and small intestinal alkaline phosphatase.

Colonic and small intestinal alkaline phosphatase extracts were studied biochemically and electrophoretically to elucidate the source of a reported difference in cellulose acetate electrophoretic mobility. Both preparations were inactivated with 0.5 mmol/L L-phenylalanine but retained full activity in the presence of 1.0 mmol/L tetramisole. Treatment with neuraminidase changed a minor fraction of the small intestinal but the major portion of the colonic alkaline phosphatase to a cathodically migrating form. The most likely explanation for our findings is that the colon and small intestinal alkaline phosphatase are mixtures of the same multiple forms but in different proportions.

Alkaline Phosphatase↗
PubMed1984

Effects of Cu deficiency on photosynthetic electron transport.

The role of copper (Cu) in photosynthetic electron transport was explored by using Cu deficiency in sugar beet as an experimental approach. Copper influenced electron transport at two sites in addition to plastocyanin. Under mild deficiency (0.84 nmol of Cu per cm(2) of leaf area), electron transport between the two photosystems (PS) is inhibited but not electron transport within PS I or PS II measured separately. The chlorophyll/plastoquinone ratio was normal in Cu-deficient plants. However, the breakpoint in the Arrhenius plot of electron transport was shifted towards a higher temperature. It is concluded that Cu is necessary to maintain the appropriate membrane fluidity to ensure the mobility of plastoquinone molecules to transfer electrons between the two photosystems. Under severe deficiency (0.22 nmol of Cu per cm(2) of leaf area) both PS II and PS I electron transports were inhibited and to the same extent. PS II electron transport activity could not be restored by adding artificial electron donors. Polypeptides with M(r)s of 28,000 and 13,500 were missing in Cu-deficient chloroplast membranes. In PS II particles prepared from normal chloroplasts of spinach, 2 atoms of Cu per reaction center are present. We conclude that Cu influences PS II electron transport either directly, by participation in electron transfer as a constituent of an electron carrier, or indirectly, via the polypeptide composition of the membrane in the PS II complex.

Journal Article↗
PubMed1984

Variation in photosynthetic pigments and plastoquinone contents in sugar beet chloroplasts with changes in leaf copper content.

The changes in the contents of chlorophyll (Chl) a, Chl b, carotenoid, and plastoquinone in sugar beet (Beta vulgaris) chloroplasts were investigated during Cu deficiency and resupply. With the onset of Cu deficiency, extrachloroplastic Cu decreased more rapidly than chloroplast Cu, which eventually accounted for all of the Cu present in the leaf. The ultrastructure of Cu-deficient chloroplasts did not differ from the control except in very young, severely deficient leaves. During Cu depletion and resupply, Chl a, Chl b, carotenoid, and plastoquinone contents changed concomitantly. Because of the concurrent changes in the contents of terpenoid-containing pigments and plastoquinone with Cu depletion and resupply, we suggest that Cu might be involved in the regulation of the early steps of terpenoid biosynthesis prior to the formation of geranyl-geranyl-pyrophosphate.

Journal Article↗