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Biomedical subjects

A Balogh

Publications and source records attributed to A Balogh.

At least 19 recordsLinked to original sources
PubMed1992

[Preparation for elective colon surgery using the mannitol-ceftriaxone method].

The study includes 450 patients undergoing elective colorectal surgery. Patients were divided in three groups. 140 patients were prepared with conventional enema and purgatives and a Neomycin-metronidazole prophylaxis. 160 patients of the second group were prepared with mannitol (10%) oral 12 hours before the operation and a single dose of ceftriaxone (Rocephin) 2 g intravenously 2 hours before surgery. 150 patients of the third group were prepared with mannitol by the same way described above, and a combination of ceftriaxone 2 g i. v. and metronidazole 500 mg. i. v. two hours before the operation. The study proved that the mannitol combined with ceftriaxone provides a sufficient preparation for colorectal surgery within 12 hours prior the operation. The rate of septic complications and septic deaths was higher in the first group then in the two others. The combination of metronidazole used in the third group showed no advantage versus single dose ceftriaxone alone.

Cathartics↗
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

Intra-individual variability of caffeine elimination in healthy subjects.

Caffeine is a popular test substance for assessing the activity of hepatic drug metabolizing enzymes in vivo and in vitro. A correct estimation of the relative magnitudes of intra-individual and inter-individual variations in caffeine elimination is significant for the use of the elimination parameter of caffeine to characterize the biotransformation capacity of a specific form of cytochrome P-450 (1AII) in vivo. The purpose of this study is to demonstrate the magnitudes of fluctuation of caffeine-clearance and half-life as well as inter- and intra-individual comparison in 12 healthy male subjects. Compared to the high reproducibility of caffeine decay curves in each healthy male, caffeine elimination varied more extensively between subjects. The distribution of variance amounted to: intra-individual 21.4%, inter-individual 78.6%. The knowledge of variance provided precise evidence of the sample size, which is necessary to prove previously defined differences.

Adult↗
PubMed1991

Chlamydia trachomatis infection among Hungarian teenage girls.

The presence of Chlamydia trachomatis antigen was examined in 20 sexually active teenage girls by enzyme immunoassay to prove chlamydial infection. Seven of the study group showed evidence of C. trachomatis infection. The infection was more frequent in girls who used a non-barrier method for contraception and had more than four sexual partners previously. Screening for and treatment of C. trachomatis infection in high-risk teenage girls is recommended.

Adolescent↗
PubMed1991

Redox active sulfhydryls are required for fructose 2,6-bisphosphate activation of plant pyrophosphate fructose-6-phosphate 1-phosphotransferase.

The classical, alpha/beta-subunit form (Q2) of green tomato pyrophosphate fructose-6-phosphate 1-phosphotransferase (PFP, EC 2.7.1.90), a cytosolic enzyme functional in carbohydrate metabolism, was rapidly inactivated on incubation with the oxidant 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB). Analysis of the DTNB-treated sample by a fluorescence procedure revealed that inactivation was accompanied by oxidation of sulfhydryl groups, primarily on the alpha-subunit. Phosphate metabolites--fructose 2,6-bisphosphate, fructose 1,6-bisphosphate, Pi, and PPi--protected against DTNB inactivation to varying degrees. The Km values for fructose 6-phosphate and PPi were not changed by DTNB treatment, but the capability for activation by fructose 2,6-bisphosphate was severely diminished. The oxidative inactivation of PFP was reversed by dithiothreitol, but not by monothiols (reduced glutathione or beta-mercaptoethanol). Reactivation was accompanied by restoration of the ability to undergo activation by fructose 2,6-bisphosphate. The findings suggest that sulfhydryl groups are essential for the activation of PFP by fructose 2,6-bisphosphate and raise the possibility that a reversible change in their redox status can take place under certain conditions. Evidence that this is the case was obtained with a preparation from wheat flour which, in the absence of an added oxidant, required reduction by a dithiol for activation by fructose 2,6-bisphosphate (dithiothreitol and reduced thioredoxin h).

Dithionitrobenzoic Acid↗
PubMed1991

[Effect of levonorgestrel and ethinyl estradiol and their combination on biotransformation reactions].

Caffeine is mainly metabolized by 3-methylcholanthreneinducible cytochrome P-450, whereas metamizol (Analgin) is probably mainly metabolized by the phenobarbital inducible cytochrome P-450 family. Therefore the elimination of caffeine from serum and the elimination of the main metabolites of metamizol in urine reflect the activity of these two cytochrome P-450 families. Sex hormones can influence the activity of cytochrome P-450. Intake of levonorgestrel (0.125 mg) daily for 14 days reduced the metabolism of caffeine slightly, but the elimination of metamizol-metabolites is not influenced. Longterm administration of levonorgestrel (0.250 mg daily) for three months did not change the metabolisms of both model substances tested. In contrast, ethynylestradiol (0.050 mg) alone and also the combination with levonorgestrel markedly retarded the elimination rate of caffeine and metamizol-metabolites. This fact should be taken into consideration in drug therapy.

Adult↗
PubMed1991

[The bioequivalence of doxycycline in two preparations in capsule form].

In a randomized cross-over study the bioavailability of doxycycline (CAS 17086-28-1) in two preparations was examined by determining AUC and Cmax. The bioavailability of Doxycyclin-Kapseln (T = test preparation) relatively to a reference preparation (R) in 20 healthy subjects. Statistical analysis of plasma concentration curve and maximum concentration showed no differences between the pharmaceutical preparations tested. Both preparations proved to be bioequivalent.

Adult↗
PubMed1991

Gonadotropin-releasing hormone analogues inhibit cell proliferation and activate signal transduction pathways in MDA-MB-231 human breast cancer cell line.

A novel gonadotropin-releasing hormone (GnRH) agonist (folligen) which stimulates follicular maturation has been developed in our laboratory. The direct effect of folligen and a well-known superactive GnRH analogue, buserelin, on the MDA-MB-231 human breast cancer cell line was investigated. Folligen was found to be slightly more active in inhibiting cell proliferation than buserelin, and significant differences were found in the signal transduction pathways activated by these analogues. These results demonstrate for the first time that tyrosine kinases and/or phospholipid turnover together with protein kinase C activation can be directly involved in the antitumor activity of GnRH analogues. The results also suggest that folligen and buserelin might have a different mechanism of action on this human breast cancer cell line.

Antineoplastic Agents↗
PubMed1990

Sexual steroid levels and their clinical significance in the early neonatal age.

Serum concentrations of progesterone (P) and estradiol (E2) in the umbilical cord blood were measured in healthy full term newborn infants and were related to the serum levels of indirect bilirubin at 72 hr postpartum in the same group of neonates. In those having higher concentration of bilirubin than 204 mumol/l at 72 hr after birth, cord P and E2 levels were significantly higher than in the rest of the group. Furthermore, strong correlation was found between serum levels of progesterone at 24 hr after birth and that of bilirubin at 72 hr postpartum in the same subjects. According to the authors' conclusion serum progesterone levels 24 hours after birth prognosticate the occurrence of neonatal hyperbilirubinaemia.

Bilirubin↗
PubMed1990

[Effect of a new gestagen--dienogest--and its combination with ethinyl estradiol on the activity of biotransformation reactions].

Caffeine is mainly metabolized by 3-methyl-cholanthrene-inducible cytochrome P-450, whereas metamizol (Analgin) is probably mainly metabolized by phenobarbital inducible cytochromes P-450. Therefore the elimination of caffeine from serum and the amount of the main metabolites of metamizol excreted into urine reflect the activity of these two cytochrome P-450 families. Sex hormones can influence the activity of cytochrome P-450. Dienogest is a new gestagen, used for temporary contraception. We investigated the effect of this new sexual hormone alone and in combination with ethynylestradiol on the elimination of both testdrugs. In 10 healthy volunteers dienogest 2 mg daily for 14 days have no effect on the metabolism of model drugs whereas the combination with 0.05 mg ethynylestradiol has an influence on the elimination of caffeine and metamizol.

Adult↗
PubMed1989

Diagnosis and treatment of inflammatory intestinovesical fistulas.

The histories of 3 patients operated for inflammatory intestinovesical fistulas are reviewed. Two of them were treated for colovesical, one for ileovesical fistula. The questions concerning the development, diagnostics and surgical management are discussed in detail. The importance of cystoscopy in diagnosis is emphasized. In all three patients one-session operations were performed with good results.

Adult↗
PubMed1988

Ovarian function after the menarche and hormonal contraception.

The aim of the study was to determine the date of regular ovulation after the menarche to better understand the physiology of female adolescence, especially as it pertains to the use of hormonal contraception. Early morning urine samples were collected from 51 girls in the perimenarche for 9 weeks semi-annually during 2 years. Estrone- and pregnanediol-3-glucuronide values were determined. Cycles lasting 35-40 days at the onset of menses shortened to 28 days after the 23rd-25th cycle. Menses reached a 5.0-5.5 day average length at about the same time. After the 20th cycle, ovulation could be demonstrated in more than 50% of the study patients. Using a scoring system, regular ovulation could be expected on the basis of somatic data with scores of greater than 16. Hormonal contraception may be prescribed 2 years after the menarche, based on scores of greater than 16 and ovulation proven be hormonal cytology and basal body temperature.

Adolescent↗
PubMed1988

Comparison of the tyrosine kinase activity with the proliferation rate in human colon solid tumors and tumor cell lines.

The role of the tyrosine kinase signal transduction pathway was investigated in human colon solid tumors and colon tumor cell lines. A high level of tyrosine kinase activity was found in 7 of the 27 human solid tumors tested (26%). In these cases, a close correlation between the level of tyrosine kinase activity and the high ratio of the S phase cells has been demonstrated (r = 0.8418). High autophosphorylation accompanied by a high proliferation capacity was detected in 8 cases (29.6%). In 12 cases (44%) low tyrosine kinase activity with a lower proliferation rate was found. Seven of the 8 human colon tumor cell lines tested showed tyrosine kinase activity. Differentiation-inducing agents, such as sodium butyrate and retinoic acid, have been applied to influence the rate of cell proliferation. Treatment with 5 mM sodium butyrate (24 h) and 10 microM retinoic acid (48 h) effectively decreased the fraction of S phase cells and 3H-thymidine incorporation. The tyrosine kinase activity fell to 9-22% and to 44-65% of the original value in the case of the sodium butyrate and retinoic acid treatment, respectively. Our results suggest that a significant part of human colon tumors have an active tyrosine kinase signal transduction pathway and that tyrosine kinase plays a role in the process of proliferation rather than in the process of differentiation in these human colon tumor cell lines.

Butyrates↗
PubMed1988

[Metamizol-caffeine elimination in females with increased serum aminotransferase activities treated with steroidal oral contraceptives].

The elimination of caffeine from the plasma and the excretion of the major metabolites of metamizol (AnalginR) in the urine was studied in 25 women on long-term oral steroid contraceptives. Both tests allowed to draw conclusions about metabolic liver function. A steroid-induced delay of the elimination of caffeine in clinically healthy women with/without serologic elevation of aminotransferase activities was demonstrated. --We regard this as the consequence of an inhibition of the cytochrome P-450-dependent poly-functional oxidases of the P-450MC type, which was produced by oral contraceptives. The differences in the elimination of metamizol were not significant.

Adult↗
PubMed1987

The influence of phenobarbital on the pharmacokinetics of propranolol in pregnancy.

In 7 pregnant hypertensive patients the elimination half-life of propranolol was enhanced to 6.1 +/- 1.2 h in comparison to 4.4 +/- 0.4 in 9 nonpregnant females. In 8 out of 11 pregnant hypertensive patients in the 29th week of gestation treated with 90 mg phenobarbital daily for at least 7 days before starting propranolol therapy, the half-life of propranolol was 3.1 +/- 0.4 h only. This significant difference between pregnant women with and without phenobarbital pretreatment is discussed as enzyme induction by phenobarbital.

Drug Interactions↗