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Biomedical subjects

A Gömöry

Publications and source records attributed to A Gömöry.

At least 19 recordsLinked to original sources
PubMed2006

Alkane isomers: presence in petroleum ether and complexity.

The presence and absence of alkane isomers in petroleum and petroleum derivatives depend on the complexity of these structures. It was assumed that the more complex the structure is the less probable it is that that the molecule can be detected in any petroleum derivative. Complexity is a vague concept, which has not been defined in quantitative terms yet, and therefore there is no experimental method, which could be used to determine 'complexity'. Mass spectrometry and infrared spectroscopy in combination with gas chromatography were used to identify the various structural isomers of alkanes in petroleum ether. The isomers were categorised in quantitative terms by using topological indices and linear discriminant analysis. It was found that alkanes possessing a more complex, highly branched structure are less probable to be detected in petroleum ether than isomers with a simpler backbone structure. It was proposed that the experimental 'measure' of the complexity of isomer(i) should be proportional to 1/C(i), where C(i), denotes the concentration of isomer(i) in a (primary) petroleum derivative.

Alkanes↗
PubMed2002

Mechanistic investigation of the interaction between bisquaternary antimicrobial agents and phospholipids by liquid secondary ion mass spectrometry and differential scanning calorimetry.

Mechanisms of interaction between the antimicrobial drugs decamethoxinum and aethonium, which are based on bisquaternary ammonium compounds, and a phospholipid component of biological membranes, dipalmitoylphosphatidylcholine, were studied by means of liquid secondary ion mass spectrometry (LSIMS) and differential scanning calorimetry (DSC). Supramolecular complexes of the drugs with this phospholipid were recorded under secondary ion mass spectrometric conditions. The dependence of the structures of these complexes on structural parameters of the dications of the bisquaternary ammonium compounds was demonstrated. Tandem mass spectrometric investigations of the metastable decay of doubly charged ions of decamethoxinum and aethonium complexes with dipalmitoylphosphatidylcholine allowed estimation of structural parameters of these complexes in the gas phase. Interactions of decamethoxinum and aethonium with model membrane assemblies built from hydrated dipalmitoylphosphatidylcholine were studied using DSC. It was shown that while both drugs can interact with model membranes, the mechanisms of such interactions for decamethoxinum and aethonium differ. The correlation between the nature of these interactions and structural and electronic parameters of the dications of the two bisquaternary agents is discussed. Interpretation of combined mass spectrometric and calorimetric experimental data led to proposals that the molecular mechanisms of antimicrobial action of bisquaternary ammonium compounds are related to their effect on the membrane phospholipid components of microbial cells.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed2001

An alternative solid phase peptide fragment condensation protocol with improved efficiency.

The success of solid phase peptide synthesis is often limited by the aggregation of the growing peptide chains on the resin. Working from the results of a study of model coupling reactions in solution between Z-Gly-Phe-OH and H-Phe-OBzl, we have achieved higher efficiency in the repetitive solid phase fragment condensation of VGVAPG, in a 3:1 chloroform-phenol solvent system, using diisopropylcarbodiimide (DIC) as coupling agent, and a combination of 3-hydroxy-3,4-dihydro-4-oxo-1,2,3-benzotriazine (HODhbt) and its tetrabutyl ammonium salt as additive, than in DMF with DIC and HODhbt alone.

Amino Acid Sequence↗
PubMed1984

Iatrogenic aortocaval fistula secondary to intervertebral disc surgery. A case report.

A case of iatrogenic aortocaval fistula is presented. The fistula arose in association with lumbar disc surgery. Its presence was immediately suspected and was promptly confirmed by aortography. Sudden deterioration of the patient's condition necessitated surgical correction of the fistula before the elected date. The successful corrective operation is described and some preventive recommendations are made.

Aorta, Abdominal↗
PubMed1980

Investigations on the flucloxacillin levels in human serum, lung tissue, pericardial fluid and heart tissue.

Following intramuscular administration of 500 mg flucloxacillin, the levels of this antibiotic were measured in the serum, lung, and heart tissue as well as pericardial fluid obtained during 24 lung and 19 heart operations. Between 55 and 160 min following administration, the intact, inflamed, and tumorous lung tissue pieces contained 3.3-4.0, 2.0-2.7, and 1.5-2.4 mcg/g flucloxacillin, respectively, representing 16-36, 13-16, and 10-18% of the actual serum levels. Pericardial fluid contained practically no flucloxacillin. The cardiac auricle contained 2.3-3.5 mcg/g between 35 and 130 min after administration; the mitral valve showed 1.1-2.5 mcg/g between 90 and 170 min afterward, whereas in the aortic valve 1.6 mcg/g was found between 105-220 min later. These concentrations represented 16-20, 7-22, and 12% of the actual serum levels. Both the serum and tissue levels proved to be higher than those of oxacillin at the same dosage. The flucloxacillin levels of the serum and tissues studied were much higher than the minimum inhibiting concentrations for the sensitive bacteria. Therefore, flucloxacillin is considered an excellent antibiotic for the treatment of respiratory infections and endocarditis, whereas its levels in the pericardial fluid show it insufficient for treatment of pericarditis.

Adult↗
PubMed1979

Embolism of heart tissue to the middle cerebral artery as a complication of heart surgery.

After suture closure of an intraarterial septal defect an atrioventricular block occurred in a 6 years old child. Therefore, the suture was removed and the defect closed by a Dacron patch. The sinus rhythm returned. After the operation convulsions occurred, the patient died after 16h which was considered to be due to cerebral air embolism. Autopsy confirmed a correct operation, but the right middle cerebral artery has been found to be completely occluded by heart muscle and pericardial fat tissue.

Autopsy↗
PubMed1979

Amikacin: in vitro bacteriological studies, levels in human serum, lung and heart tissue, and clinical results.

The amikacin sensitivity of bacteria cultured from 3282 clinical cases of mixed type was determined. Gentamicin and amikacin were equally effective against E. coli strains. Amikacin inhibited the growth of more Pseudomonas aeruginosa strains than did gentamicin. Against Gram-positive bacteria gentamicin proved to be more effective. Many of the gentamicin-resistant strains were sensitive to amikacin. Amikacin levels were measured during 21 pulmonary and 14 heart operations, subsequent to a intramuscular administration of 500 mg amikacin. The serum contained 17-20 microgram/ml amikacin, in the intact, inflamed and tumourous parts of removed lung tissue 9, 6 and 6 microgram/g concentrations were detected, respectively, whereas the cardiac auricle and the pericardial fluid contained 3-4 and 2-4 microgram/ml, respectively. These amikacin levels reach or in most cases even exceed the minimal inhibiting concentrations against the bacteria. Therefore, amikacin is excellent for the treatment of respiratory infections, pericarditis and endocarditis caused by Gram-negative, gentamicin-resistant bacteria. Amikacin treatment of 8 patients with grave diseases as well as the successful local administration of amikacin based on the therapy of 55 cases of surgical suppurations is reported.

Amikacin↗
PubMed1977

Gentamycin in cardiac surgery.

Gentamycin concentration in the serum, pericardial fluid, auricle, valve and papillary muscles of 14 patients subjected to cardiac surgery was determined after intramuscular administration of 80 mg of the drug. Fifty to 140 minutes after administration the mean level in the serum was 6.0 mcg/ml, in the pericardial fluid 0.6 mcg/ml, in the auricle 5.8 mcg/g, while after 120 to 240 minutes in the valve 1.2--9.6 mcg/g and in the papillary muscles 2.0--3.6 mcg/g of gentamycin was measured. Consequently, an efficacious gentamycin concentration can be achieved in the cardiac tissues but not in the pericardial fluid which makes gentamycin excellently suited for the prevention and treatment of the infectious complications of heart operations.

Adolescent↗
PubMed1975

[Methicillin levels in the human serum, pericardial effusion and myocardium].

The antibiotic level in the serum, pericardial fluid and myocardium of 11 patients prepared for heart surgery was tested by means of the agar-diffusion method after the intramuscular administration of 1 g of methicillin. The mean level after 1 to 3 hours was 14.7 mcg/ml in serum, 1.7 mcg/ml in the pericardial fluid and 8.2 mcg/g in the myocardium. In the case of drug sensitivity, the myocardial methicillin concentration is sufficient for the treatment of Gram-positive infections. If the infection is localized in the pericardium, higher doses, local applications, drug combination or complex therapy might be called for.

Adolescent↗