Biomedical subjects

A Somogyi

Publications and source records attributed to A Somogyi.

At least 19 recordsLinked to original sources

PubMed1995

[Incidence of perioperative myocardial necrosis in the course of coronary bypass surgery].

Authors report an analysis of 101 patients' perioperative data in the view of myocardial necrosis development. Perioperative myocardial infarction is defined as simultaneous detection of new Q wave, and myocardial specific enzyme release with concomitant, transient pump failure. They conclude by the data of patients operated upon, that the quoted criteria were detected simultaneously in 9 patients. Other 7 patients had CK-MB levels of pathological level, but without evidences of any other myocardial infarction criteria. Minimal myocardial mass loss as a sort of terminology is introduced, which is obviously not considered as equal to true myocardial infarction.

Adult↗

PubMed1995

Thermal decomposition kinetics of protonated peptides and peptide dimers, and comparison with surface-induced dissociation.

Rate constants for the unimolecular decomposition of peptide monomer and dimer ions by thermal and surface-induced dissociation (SID) are measured and compared. Rate constants for thermal dissociation are measured in a heated wide-bore capillary flow reactor attached in front of the capillary leading into the mass spectrometer. Thermal decomposition of the leucine enkephalin ion (YGGFL)H+ is observed between 600 and 680 K with rate constants of 20-200 s-1, and yields many of the same fragments as SID at 35 eV, although with different relative intensities. The thermal decomposition yields the Arrhenius parameters Ea = 38.3 kcal/mol, log A = 15.7. The decomposition of the monomer and dimer ions are also observed by using SID on C18 and fluorinated hydrocarbon surfaces, with rate constants of 2 x 10(4) to 40 x 10(4) s-1. The SID activated monomer ions are assigned equivalent temperatures of 710-840 K by extrapolation of the thermal activation parameters. The protonated dimer ion (YGGFL)2 H+ decomposes thermally at 500-540 K to yield the monomer ion. The dimer also decomposes by SID at low collision energies 10-20 eV on both surfaces to yield the monomer ion, and at much higher energies of 60-80 eV to yield fragments identical to the decomposition of the monomer. The large energy requirement for fragmentation from the dimer is due to energy deposition into more degrees of freedom plus the additional energy required for dissociation of the dimer to the monomer.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1994

[Treatment of methimazole-induced agranulocytosis with granulocyte-macrophage colony stimulating factor].

The authors treated a patient with methimazol (Metothyrin)-induced agranulocytosis with human recombinant granulocyte-macrophage colony stimulating factor (GM-CSF). On day seven, after combined antibiotics, corticosteroid and at a dose of 270 ug daily subcutaneous GM-CSF therapy the septic state of the patients rapidly cured and the leucocytes reached the peripheric blood. No side effects were found. The publication of this case history might help to determine the place of human GM-CSF-s therapy in the treatment of agranulocytosis of different origin.

Administration, Cutaneous↗

PubMed1994

[Hypothetical connection between diabetes mellitus and free radical reactions in arteriosclerosis].

Diabetic patients develop arteriosclerosis at an early age. Their disease progresses more rapidly than that of nondiabetics, due to the underlying cause of arteriosclerosis of which the origin is still unknown. Much attention has been paid recently to the causative role of glycosilated lipoproteins, free radical reactions and hyperinsulinaemia--insulin resistance. Disturbances of the carbohydrate metabolism are accompanied by disorders in lipid metabolism and in the antioxidant system. While proteins undergo glycosilation, free radicals are being released from inflamed cells and, during the course of glycosilation with subsequent lipid peroxidation. Oxidation of lipids and proteins form the basis of pathological processes that might initiate the development of arteriosclerosis. There are attempts to influence the above processes by scavengers--e.g. vitamins, Ca-antagonists, angiotensin converting enzyme inhibitors and antilipaemic agents.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1994

Stable myocardial performance at clamped aorta based solely on the internal mammary artery graft flow: a functional test.

Authors report their experiences with arterial revascularization of the heart using the internal mammary artery (IMA). A method of intraoperative measurement of the free cut end and the effective graft flow of the IMA after meticulous anatomical dissection is described. Free cut end IMA flow was measured both at systemic and extracorporeal pump perfusion pressure and was found as 145+/-26 ml/min and 135+/-16 ml, respectively. A method of measurement of the effective IMA graft flow was introduced and described. An attempt was made to identify factors leading to stable myocardial performance based only on the IMA graft flow just prior to declamping the aorta. The phenomenon is considered as a reliable functional test regarding precise IMA harvesting, anastomosis construction and IMA graft flow capacity.

Adult↗

PubMed1994

The influence of pharmacogenetics on opioid analgesia: studies with codeine and oxycodone in the Sprague-Dawley/Dark Agouti rat model.

In the Sprague-Dawley (SD) rat, the O-demethylation of codeine to morphine is catalyzed by cytochrome P4502D1 (CYP2D1), which is absent in the female Dark Agouti (DA) rat. Oxycodone is similar in structure to codeine but, in contrast, has an analgesic potency in humans similar to morphine. The aim of the study was to test whether the DA rat and the SD rat pretreated with the CYP2D1 inhibitor quinine showed attenuation in analgesia to codeine and oxycodone. With the use of the tail flick model, dose-response curves were constructed to codeine, morphine, oxycodone and oxymorphone (the O-demethylated metabolite of oxycodone) in both rat strains. Codeine did not induce analgesia in the DA rat and there was a 60% reduction in codeine analgesia in the SD rat pretreated with quinine in comparison to the untreated SD rat. In the DA rat, the ED50 to oxycodone was increased 10-fold but there was a significant (P = .0001) prolongation in the duration of analgesia in comparison to that in the untreated SD rat. In the quinine-pretreated SD rat, there was no reduction in oxycodone analgesia but the duration of analgesia was also prolonged. It was concluded that 1) codeine-mediated analgesia requires the formation of morphine through the functional activity of CYP2D1 and 2) oxycodone-mediated analgesia may only be partly dependent on CYP2D1.

Analgesia↗

PubMed1993

[Diabetes mellitus and lipoproteins].

The leading cause of death of diabetic patients is coronary heart disease developing on the basis of accelerated arteriosclerosis. Lipoprotein disorders commonly accompanying diabetes mellitus (DM) promote this process and their joint presence represent cumulated risks for patients. The present review summarizes the various disorders accompanying the two types of DM. In case of insulin-treated, type I, well adjusted DM without signs of primary disturbances of lipid metabolism, quantitative lipid alterations cannot be found. In poorly treated DM with insufficient insulin levels the accumulation of triglyceride particles is due to diminished lipoprotein lipase activity. The main consequence is hyperchylomicronaemia but all three lipoprotein classes are affected. The most characteristic lipid abnormalities in non-insulin-dependent (type II) DM are hypertriglyceridaemia, increased VLDL cholesterol concentration and decreased HDL levels, which frequently remain unchanged even upon the proper treatment of glucose metabolism. The alterations are related to increased free fatty acid levels and decreased glucose uptake resulting from elevated insulin levels. In about one-fourth of cases, primary hyperlipaemia is also present. The treatment of primary and secondary lipid disorders accompanying DM by diet and drugs is of the most uttermost importance.

Diabetes Mellitus, Type 1↗

PubMed1993

Fragmentation of protonated peptides: surface-induced dissociation in conjunction with a quantum mechanical approach.

This paper describes the results of a systematic investigation designed to assess the utility of surface-induced dissociation in the structural analysis of small peptides (500-1800u). A number of different peptides, ranging in mass and amino acid sequence, are fragmented by collision with a surface in a tandem mass spectrometer and the spectra are compared with data obtained by gas-phase collisional activation. The surface-induced dissociation spectra provide ample sequence information for the peptides. Side-chain cleavage ions of type w, which are generally detected upon kiloelectronvolt collisions with gaseous targets but not upon electronvolt collisions with gaseous targets, are detected in the ion-surface collision experiments. A theoretical approach based on MNDO bond order calculations is suggested for the description of peptide fragmentation. This model, supplemented by ab initio calculations, serves as a complement to the experimental work described in the paper and explains (i) the easy cleavage of the amide bond, (ii) charge-remote backbone and side-chain cleavages, and (iii) the influence of intramolecular H-bonding.

Amino Acid Sequence↗

PubMed1993

[Simultaneous surgery for trivalvular and ischemic heart disease as well as calcification of the ascending aorta].

Authors present a case report about the surgical management of trivalvular and ischemic heart disease. The strategy of surgery: venous, arterial revascularisation, valve replacements, valvular plasty is discussed in conjunction with the management of the calcified ascending aorta. The details of the procedure and data of the early follow up period (6 months) are presented.

Aorta↗

PubMed1993

Nurturing and breast-feeding: exposure to chemicals in breast milk.

All chemicals that are not normal constituents of human milk should be considered undesirable contaminants. In the present review, the following substances detected in human milk are considered: persistent organochlorine pesticides; polychlorinated biphenyls (PCB); polychlorinated dibenzodioxins (PCDD) and dibenzofurans (PCDF); polybrominated compounds; polycyclic aromatic hydrocarbons (PAH); trace elements; mycotoxins; nitrate, nitrite, nitrosamines; nicotine, caffeine, ethanol; and drugs. The levels of most of these substances found in human milk were within a range that would not constitute health hazards for breast-fed infants. For many of these, there is a comfortable safety margin. This applies also to organochlorine pesticides and PCB, particularly since, as a result of their discontinued use, the levels of these compounds have clearly declined in recent years. On the other hand, the aflatoxin burden mediated through breast milk, at least in certain tropical countries, appears to pose a definite health hazard. Detailed reference are given on the contamination of human milk with PCDD/PCDF which has to be considered as a matter of concern from the viewpoint of preventive public health. Although the low PCDD/PCDF levels found in the adipose tissue of infants indicate that there is no appreciable health risk emanating from these substances for breast-fed infants, appropriate measures to reduce the current rate of their emission into the environment have to be taken.

Body Burden↗

PubMed1991

Lack of effect of paracetamol on the pharmacokinetics and metabolism of codeine in man.

Plasma and urine concentrations of codeine and its measurable metabolites were determined by HPLC in six healthy subjects after a single 30 mg oral dose of codeine either alone or after 7 doses of 1 g paracetamol 8 hourly. After codeine alone, the t1/2 (h), AUC (mumol.l-1.h) and CLR (ml.min-1) for codeine were 2.2, 0.81, and 252 respectively. These were not significantly altered by paracetamol: 2.2, 0.84, and 291 respectively. For codeine-6-glucuronide the values were 2.4, 22.0, and 29.7 respectively. These were not significantly different from those after codeine plus paracetamol: 2.4, 21.9, and 39.6. There were no significant differences between the two treatments in the apparent partial clearances (ml.min-1) of codeine to morphine (88 codeine alone, 70 codeine plus paracetamol), to norcodeine (71 codeine alone, 88 codeine plus paracetamol), and to codeine-6-glucuronide (820 codeine alone, 1022 codeine plus paracetamol). The urinary excretion of codeine-6-glucuronide, morphine, norcodeine, and codeine were not significantly different between the two treatments.

Acetaminophen↗

PubMed1991

Metabolic denitrosation of N-nitroso-N-methylaniline: detection of amine-metabolites.

The enzymatic denitrosation of N-nitroso-N-methylaniline (NMA) was investigated by measuring the resulting amine metabolites when NMA was incubated with liver microsomes of PB-pretreated mice. Aniline was found to be the main amine metabolite. Small amounts of the secondary amine, N-methylaniline (MA) and its metabolite, p-methylaminophenol (p-MAP), could also be detected. Incubation of MA resulted in the formation of aniline and p-MAP. The velocity of the metabolism of MA was somewhat faster than that of NMA. On the basis of the measured Vmax values the formation of aniline from MA or from NMA proceeded at nearly identical rates. The dissociation constants as a measure of binding affinity to cytochrome (cyt.) P-450 were determined by measuring the binding spectra. NMA has one Ks of 3.1 mM, whereas MA shows two apparent Ks values, 650 microM and 25 mM, respectively. The results are discussed in relation to the enzymatic mechanism of denitrosation of NMA.

Aniline Compounds↗

PubMed1991

Left ventricular beta 1 and beta 2 adrenoceptor mRNA expression in normal and volume overloaded human heart.

STUDY OBJECTIVE: The aim was to determine gene expressions of beta 1 and beta 2 adrenoceptor subtypes (BAR-1, BAR-2) in normal and volume overloaded human heart. DESIGN: Tissue mRNA levels were determined by excess solution hybridisation using 35S-UTP labelled BAR-1 and BAR-2 cRNA probes. MATERIAL: Atrium, right and left ventricular subendocardium, and papillary muscle from donor hearts and papillary muscle from patients operated for mitral stenosis and mitral regurgitation were studied. MEASUREMENTS AND MAIN RESULTS: The basal levels of myocardial BAR-1 and BAR-2 mRNA expression were similar to the levels in human adipose tissue that have been reported previously from our laboratory (10-15 amol mRNA.micrograms-1 total nucleic acids). No differences in BAR-1 and BAR-2 mRNA expression were observed between various parts of the normal heart. In papillary muscle, BAR-1 and BAR-2 mRNA levels were 8.8 (SEM 5.1) and 10.2(6.6) amol.micrograms-1 total nucleic acids, respectively. Furthermore, no differences in BAR mRNA expression were observed between myocardium subjected to mitral stenosis as compared to normal myocardium. On the other hand, patients with mitral regurgitation expressed significantly lower levels of both BAR-1 and BAR-2 mRNA, at 4.8(1.0) (p less than 0.05) and 2.6(1.1) (p less than 0.001) amol.micrograms-1 total nucleic acids, respectively. The ratio BAR-1/BAR-2 mRNA was higher (p less than 0.01) in mitral regurgitation than in the normal heart. CONCLUSIONS: Myocardium from different parts of the normal human heart, where different pressure work is generated, express similar levels of BAR-1 and BAR-2 mRNA. With volume load a significant decrease in BAR mRNA levels was observed, which was more marked for BAR-2 mRNA. This difference in specific mRNA levels in patients with mitral regurgitation indicates an independent regulation of the expression of these two receptor subtypes.

Adolescent↗

PubMed1990

Determination of endogenous concentrations of N1-methylnicotinamide in human plasma and urine by high-performance liquid chromatography.

A high-performance liquid chromatographic assay for the determination of endogenous plasma and urine concentrations of N1-methylnicotinamide was developed. N1-Methylnicotinamide and N1-ethylnicotinamide (internal standard) are reacted with acetophenone in a strong base at 0 degree C, formic acid is added, and the reaction mixture is heated in a boiling water bath, resulting in the formation of fluorescent derivatives. These derivatives were chromatographed on a C18 reverse-phase column using a mobile phase of acetonitrile-triethylamine and 0.01 M heptanesulfonic acid adjusted to pH 3.2. Fluorescent detection was achieved using 366-nm excitation and 418-nm emission filters. Precision and accuracy were generally greater than 90%, interfering peaks did not cochromatograph, and the limit of quantification was 2 ng/ml in plasma using a 0.2-ml sample. The method was used to examine the concentrations of endogenous N1-methylnicotinamide in the plasma of 36 subjects with various pathology. The mean concentration was 18 ng/ml and the range was 6.2 to 116.7 ng/ml. The assay represents a marked improvement on previous methods and is suitable for routine clinical monitoring.

Acetophenones↗

PubMed1990

Silibinin (Legalon-70) enhances the motility of human neutrophils immobilized by formyl-tripeptide, calcium ionophore, lymphokine and by normal human serum.

Experiments reported here were designed to investigate the effect of silibinin (extracted from Silybum marianum) on human polymorphonuclear leukocyte (PMN) motility and on leukocyte immobilizing activity of lymphokine (leukocyte inhibitory factor, LIF), formyl-Met-Leu-Phe (fMLP), calcium ionophore A-23187 and human sera inactivated by heat (HI-S). In the in vitro experiments, silibinin (1-10 micrograms/ml) failed to influence the random motility of unstimulated PMNS in agarose droplet assay, but enhanced the motility of the PMNs immobilized by fMLP, calcium ionophore, LIF or by autologous human sera. In the in vivo study, silibinin (Legalon-70) two hours after the administration was effective in enhancing spontaneous motility of leukocytes obtained from health volunteers which action could be regarded as a consequence of the decrease of leukocyte immobilizing activity being present in normal human plasma.

Blood↗

PubMed1990

Amiloride disposition in geriatric patients: importance of renal function.

1. The absorption and disposition of the potassium sparing diuretic amiloride were determined in nine elderly patients aged 71 to 87 years and in eight young (25 to 38 years) subjects following oral administration of 5 mg amiloride HCl daily to steady-state. 2. The maximum and steady-state plasma amiloride concentrations were significantly (P less than 0.05 and P less than 0.001) higher in the elderly patients. The renal clearance of amiloride was lower in the elderly than in young subjects (102 +/- 36 ml min -1 vs 300 +/- 64 ml min-1, P less than 0.001) as was the urinary excretion of amiloride (36 +/- 13 vs 62 +/- 18% of the dose, P less than 0.01). 3. The steady-state plasma amiloride concentration correlated significantly (r2 = 0.61, P less than 0.001) with amiloride renal clearance and with creatinine clearance (r2 = 0.59, P less than 0.001). There was a very strong positive correlation between renal amiloride clearance and creatinine clearance (r2 = 0.76, P less than 0.001). The slope of the regression line was 2.5 indicating substantial proximal tubular secretion of amiloride. 4. Sodium and potassium excretion, along with urine volume were significantly (P less than 0.05) lower in the elderly (by 39, 45 and 34% respectively). 5. The disposition of amiloride was highly dependent on renal function, with higher plasma amiloride concentrations in the elderly reflecting diminished renal function. The dose of amiloride should be titrated to individual response, and the lower potassium excretion in the elderly patients suggests that the dose of amiloride could be reduced in this group of patients.

Adult↗

PubMed1990

Late effect of tobanum and tobanum + furosemide therapy on the glucose tolerance of patients and on the insulin response to oral glucose doses.

The authors examined the effect of beta-blocker monotherapy (Tobanum tab = 5 mg cloranololum hydrochloricum) and beta-blocker + diuretic (Tobanum + Furosemide) combination therapy on glucose tolerance and insulin secretion in response to oral glucose doses in hypertensive non-diabetic patients. Twenty-six patients were examined (13 men, 13 women). The patients were followed up for 28 weeks after a 2-week drug-free period. The hypotensive dose was adjusted individually within 4 weeks. Oral glucose tolerance test and immuno-reactive insulin determination were performed concurrently before starting hypotensive therapy and on weeks 6, 14, and 28 of therapy. The results of the examinations were evaluated separately in two patient groups. Fifteen patients were given daily 10-20 mg Tobanum (Group I) while 11 patients received daily 10-20 mg Tobanum + 40-80 mg Furosemide (Group II). The glucose area of patients on Tobanum monotherapy did not change, insulin secretion decreased gradually (from 804 to 495 pmol/l). The decrease was significant (p less than 0.05). The glucose area of Tobanum + Furosemide-treated patients increased from 13.2 +/- 3.2 mmol/l to 16.1 + 4.9, the insulin secretion decreased from 1039 + 339 to 706 + 411 pmol/l during therapy (p less than 0.02 and p less than 0.05, resp.). When evaluating the results the decrease of insulin secretion is attributed to Tobanum effect while the deterioration of glucose tolerance may be correlated to the action of Furosemide on extrapancreatic metabolism.

Adrenergic beta-Antagonists↗

PubMed1990

[Morphologic and morphometric analysis of atheromatous changes in the aorta in silibinin-treated cholesterin-fed rabbits].

Authors studied the effect of Silibinin of antioxidative effect on cholesterin sclerosis of rabbits. Qualitative analysis of aorta sections, macroscopic and microscopic morphometric examination of aorta were the applied methods. Their results seem to show that Silibinin has a favourable influence on cholesterin sclerosis. According to their opinion only joint use of qualitative and quantitative macroscopic and microscopic methods can provide basis for really accurate judgment of any atheromatose change.

Animals↗