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Biomedical subjects

A Horváth

Publications and source records attributed to A Horváth.

At least 19 recordsLinked to original sources
PubMed1992

[Comparative study of preoperative chemotherapy and radiotherapy in squamous cell carcinoma of the oral cavity].

The results of the preoperative Co 60 irradiation and BVMM (bleomycin, vincristine, mitolactol, methotrexate) chemotherapy were compared. Both treatments were used in 50-50 advanced squamous cell cancer of the oral cavity. The general condition, size of lesion and age of the patients were similar. Surgery in the irradiated group was significantly more radical at the primary sites. Local recurrences during a three-year follow-up period were diagnosed in 36% from the radiotherapy group, whilst 8% such recurrences diagnosed in the chemotherapy group. There was no significant difference in the radicality of lymph node surgery. Lymph node recurrences occurred in 8% from the irradiated group, whilst 22% was diagnosed in the chemotherapy group. The main opinion is that BVMM chemotherapy and irradiation can be used to support one another in the interest of better result, like preoperative chemo- and postoperative radiotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Novel antitumor peptide hormones and their effect on signal transduction.

A series of novel gonadotropin releasing hormone (GnRH) and Somatostatin analogs have been developed in our laboratory and were screened for antiproliferative and signal transduction inhibitory effect. Our GnRH analog Folligen, had significant antitumor activity on DMBA induced mammary carcinomas in rats without blocking ovarian functions. The direct effect of Folligen and Buserelin has been compared on the human breast cancer cell line MDA-MB-231. Folligen was found to be more effective in inhibiting cell proliferation and significant differences were found in the signal transduction pathways activated by these analogs. Our novel Somatostatin analogs were screened for tyrosine kinase inhibition and for antiproliferative effect on human colon tumor cells and for growth hormone (GH) release inhibition in vitro and in vivo. The analog TT-2-50 was significantly more active inhibiting GH release in superfused rat pituitary cells and in vivo than native Somatostatin and it strongly inhibited tyrosine kinase and proliferation while it stimulated protein kinase C activity.

Amino Acid Sequence↗
PubMed1992

Identification of basic nuclear proteins by their boronate complex.

A new histochemical reaction for the identification of histone type basic proteins has been developed. Carbonyldiimidazol is used to activate the basic proteins of TCA-extracted nuclei, their m-aminophenylboronic acid complex is prepared, and the DNA-free, histone-containing nuclei are stained with toluidine blue at pH 5.5.

Animals↗
PubMed1992

Total and specific IgE in sera of HIV positive and HIV negative homosexual male (regulation of IgE synthesis in HIV infection).

In the course of HIV infection "atopic" symptoms can often be experienced (atopic dermatitis, asthmatic like symptoms in upper respiratory tract, sensitivity to drugs). Total IgE increase has been detected which is in inverse correlation with CD4 positive lymphocytes. Using semi quantitative and quantitative methods total and specific IgE levels of 30 HIV positive and 30 HIV negative homosexual men without atopic anamnestic data and symptoms have been determined. The age matched control groups were of 30 atopic men with active symptoms and 30 healthy, HIV negative heterosexual men. Determination of CD4, CD8 positive number of lymphocytes as well as B-2 microglobulin have been carried out. Total IgE level of HIV positive and HIV negative homosexuals was higher than that of the healthy controls and lower than that of the "atopic" controls. Specific IgE-s have been found more often in HIV positive and HIV negative homosexuals than in the normal controls. The correlation among CD4 and CD8 positive lymphocytes, and B-2 microglobulin level and total IgE level was not significant.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Prevalence and specificity of lymphocytotoxic antibodies in different stages of HIV infection.

Sera obtained from 27 HIV-infected persons were investigated for complement-dependent humoral cytotoxicity. Uninfected as well as HTLV-IIIB-infected H9 cells were used as cellular targets either before or after stimulation by phytohemagglutinin (PHA) or concanavalin A (Con-A). The degree of cytotoxicity was determined by 51Cr-release assay. Two different antibodies could be found in sera of HIV-infected persons, one being directed against HIV-induced cell surface component(s) and the other reacting with structure(s) present on activated T4 cells. Asymptomatic HIV-carries were found to have antibodies exerting complement-dependent cytotoxicity to HIV-infected T4 cells. These antibodies were reactive mainly after stimulation of HIV-infected target cells by Con-A. Sera of ARC and AIDS patients contained autoantibodies reactive with PHA-stimulated or HIV-infected T4 lymphocytes. These data suggest that HIV-specific antibodies represent an anti-viral immune defense, while autoantibodies may be important in destruction of the immune system in AIDS.

AIDS-Related Complex↗
PubMed1991

[HIV seropositivity in promiscuous heterosexual, homosexual and bisexual men and patients voluntarily reporting for screening in Hungary between 1 January 1986 and 31 December 1989].

The cumulative seroprevalence was 5.21% among the homo/bisexual men in the four years. As well as in Budapest, we experienced the increase of seroprevalence in the country, too, after a decrease in 1988. The cumulative seroprevalence was 0.44% with men and 0.04% with women in the group of the voluntary reporters in the mentioned period. The same indexes were 0.07% for men and 0.019% for women in the group of the STD patients. Seroprevalence with men increased significantly in the last year. Hungary belongs to the low-incidence area among the European countries, even though the group of homosexuals can be considered moderately infected, seroprevalence is increasing in Budapest as well as in the country and heterosexuals are also affected.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Management of waste disposal in medical institutions].

Recently new regulations were elaborated for the management of medical wastes in Austria, FRG, Canada and USA. There is no rule laying down the requirements of the management of medical wastes in Hungary. On the basis of foreign experiences the medical wastes are proposed to range into categories as follow: I. Waste that should be handled in special way within and outside the health care facilities. II. Waste, that should be handled in a special way within the health care facilities. III. General waste (municial-type waste). Basic requirement is the segregating collection of wastes. Color-coding is proposed to identify the content of containers and bags. Incinerators combined with pyrolysis and emission control unites should be preferred to the disposal of medical wastes. The author proposes to issue a rule setting out definitions and basic principles of management of medical wastes. Individual health care establishments should prepare own written policies and measures for waste handling appropriate to their specific requirements.

Austria↗
PubMed1991

Neutralizing and complement-dependent enhancing antibodies in different stages of HIV infection.

Reclustering and indirect immunofluorescence assays on MT-4 cells [carrying both CD4 and complement receptor type 2 (CR2)] were used to measure neutralizing and enhancing antibodies in sera obtained from HIV-1-infected individuals. Heat-inactivated sera were tested before and after mixing 1:1 with fresh seronegative human serum. Using heated samples, neutralizing antibodies were found in 20 out of 20 and 11 out of 19 serum samples of asymptomatic and symptomatic [AIDS, AIDS-related complex (ARC)] HIV-seropositive patients, respectively. In complement-restored samples, neutralizing activity was found in eight sera of asymptomatic patients and in none of the sera of AIDS and ARC patients; enhancing activity could be detected in four and 12 sera, respectively. A significant positive correlation was observed between the titres of neutralizing antibodies measured in the complement-restored samples and the absolute number of CD4+ lymphocytes. These findings indicate that the appearance of complement-dependent enhancing antibodies coincident with the loss of neutralizing antibodies may indicate a poor prognosis in HIV infection.

AIDS-Related Complex↗
PubMed1990

[Subglottic laryngitis treated with corticosteroid inhalation].

On basis of examinations the authors established that in case of a mild pseudocroup syndrome the inhalation of beclomethasone in itself, in more severe cases combined with racem epinephrine has a favourable effect; it shortens the period of symptoms, and effectively reduces the progress of laryngitis with resting dyspnoe. In 15 cases out of 18 patients treated without local steroids, airway stenosis increased, while in patients getting inhalative steroids only 15 cases out of 29 worsend. In practice the use of beclomethasone makes possible the home treatment in mild cases of pseudocroup. It must be considered, however, that one hour is needed while its effect develops. The progress of laryngitis can be stopped by inhalative corticosteroids, but in most severe cases they must be combined with racem epinephrine.

Adult↗
PubMed1990

[Imported food poisoning caused by fish toxins (ciguatoxin)].

Various types of fish-poisoning mainly occur in tropical areas. Saxitoxin, tetrodotoxin, scombrotoxin and clupeotoxin are heat labile while ciguatoxin, in contrast, is heat stable thus it may be the source of severe poisoning even in case of thorough cooking and baking. In December 1987 a mass alimentary poisoning occurred following ingestion of fish meat in a group returning from Cuba. The most severe case was admitted to our department with symptoms of extended paresis. Diagnosis of ciguatoxin poisoning was established based upon the history, clinical features and laboratory results. Nowadays exotic, remote "Fish-poisoning" cases have to be taken into consideration even in our country.

Ciguatera Poisoning↗
PubMed1990

Identification of nucleohistones by glycosylation and basic dyes.

Earlier examinations have shown that reducing sugars mainly react with the epsilon-amino group of lysine. After DNA extraction, lysine-rich histone proteins of alcohol fixed nuclei of rat organs were treated with glucose-6-phosphate. It was possible to selectively stain the histone type proteins of DNA negative nuclei with basic dyes.

Animals↗
PubMed1990

Neutralizing antibodies and serum interferon levels in the different stages of HIV infection.

The sera of patients infected with HIV were investigated for neutralizing antibodies (NA) and interferons. All samples from asymptomatic HIV carriers contained NA in high titres. In the sera of patients with AIDS related complex and AIDS the antibodies were found rarely and in lower titres. An early peak of acid-labile interferon (IFN)-alpha was observed in asymptomatic HIV-infected persons, and a late peak was found in AIDS patients. The data suggest that HIV NA may have beneficial effect in the asymptomatic phase. The presence of acid-labile IFN-alpha may indicate stimulation of IFN system by HIV-infected cells.

AIDS-Related Complex↗
PubMed1990

Environmental influences on the sensitization by drugs measured in peripheral blood lymphocyte chromatin.

An "allergo-kinetic" method was introduced, which measures early changes of nuclear chromatin structure of lymphocyte subpopulations. The method is used as an in vitro test for drug allergy. The comparison of data from two sampling places (Budapest-Esztergom) shows the following results: The drug allergy scores (obtained from T-cells) may reflect environmental influences on the population under study. During the 13 months period after Atomic Reactor accident in Chernobyl, both the frequency of severe skin manifestations and that of organ manifestations (without skin lesions) increased. The ratio of negative test results decreased in both of drug allergic patient groups (small town = Esztergom, large city = Budapest)--tendency to polysensibilization. The scores obtained in drug related groups of generalized urticaria and Quincke's oedema increased significantly within 13 months after accident followed by a normalization in the subsequent year.

Accidents↗