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Biomedical subjects

L Pap

Publications and source records attributed to L Pap.

18 recordsLinked to original sources
PubMed2001

Comparative evaluation of new synergists containing a butynyl-type synergophore group and piperonyl butoxide derivatives.

Cross-substituted derivatives of piperonyl butoxide (PBO) and MB-599 (proposed common name: verbutin) were synthesized and investigated as carbofuran and permethrin synergists against housefly, Musca domestica L. The majority of PBO and MB-599 derivatives were significantly more potent synergists for carbofuran than for permethrin. PBO, the most important representative of this series was not the most potent synergist for carbofuran or for permethrin. Cleavage of the methylenedioxy ring of methylenedioxyphenyl (MDP) polyether compounds resulted in complete loss of synergistic activity with both insecticides, but it could be restored or even improved by incorporating an alkynyl ether moiety into the molecule. The improved synergistic activity was found to be closely associated with the 2-butynyloxymethyl side-chain, suggesting that this can be regarded as a characteristic synergophore group. MB-599, one of the most promising compounds bearing this group showed considerably higher activity with carbofuran (synergist ratio, SR = 37.8) than with PBO (SR = 6.4). There was no significant difference between synergistic activities of MB-599 (SR = 4.6) and PBO (SR = 4) for permethrin.

Alkynes↗
PubMed2001

[Radiotherapy of childhood brain stem tumours]

STUDY OBJECTIVE: Description and evaluation of radiotherapy of inoperable brain stem tumours. Possibilities of improving therapeutic results. MATERIALS AND METHODS: Between 1987 and 2000 43 patients (23 boys and 20 girls, mean age 8.5+/-4.4 years) with brain stem tumours were treated with 6 MV and 9 MV X-ray. The doses administered ranged from 30 to 66 Gy; mean 50.41+/-7.67 Gy. Treatment in each case was performed according to CT- and /or MR-based radiotherapy plan. Since 2000 3D conformal radiotherapy plans have been prepared by using image fusion. RESULTS: All patients were followed. The mean follow-up period was 19.4 months (range: 1 to 112 months). For survival statistics the 2 to 3-year overall and symptom-free survivals were taken into account, the former ones in the function of tumour localisations. The gender of children did not affect the survival (p>0.74). No significant difference was found as to survival in the function of tumour localisation either (p>0.87). CONCLUSION: According to the literature data the results expected were not achieved by hyperfractionation and by delivering an overall focal dose of 72 to 78 Gy. Results can be improved by precise patient fixation and the routine application of 3D conformal radiotherapy plans prepared by CT- and MR-based image fusion. These together can result the correctly reproducible patient fixation, the homogenous radiation delivery in the target volume and the reduction of injury in the surrounding tissues. Irradiation should be performed also in histologically not verified tumours since a 24.6 month transitory improvement could be achieved in 60.5% of our patients.

Journal Article↗
PubMed2001

Postoperative radiotherapy of childhood medulloblastomas.

The purpose of this work is to review the result of radiotherapy in the treatment of medulloblastoma in pediatric patients. Between 1986 and 1998, 66 children (45 boys and 21 girls) received postoperative irradiation in our institute. Their mean age was 8.29 years. Irradiation was performed by linear accelerator, 36 Gy were applied in the high risk group (partial tumor resection, tumor cell positivity in the liquor, metastases within the central nervous system) and 30 Gy in the low risk group (total tumor resection, negative liquor cytology, no metastases within the central nervous system) on the entire cerebrum and spinal cord. This was followed in both groups by the application of 20-20 Gy boost irradiation on the posterior scala. Studying the survival it has been found that the surgical radicality did not significantly influence the survival chances of patients, however, with the increase in the tumor size the survival chance significantly decreases (p = 0.03). When predicting life expectancy, however, the stage of tumor, the age of patients, the risk group and the M stage yielded essential information. At the age of 8 years and less, the rate of survivors is 67.6%, for those over 8 years is 75.9% (p = 0.21), however the younger age was not significant. The appearance of metastases considerably deteriorates the chances of survival (from 81.5% to 66.7%, p = 0.02). In the low risk group of patients the 5-year survival is 80%, while in the high risk group it is significantly lower, 67.4% (p = 0.04).

Adolescent↗
PubMed2000

Distribution of inorganic elements in human autopsy tissue.

In the practice of forensic medicine, we find many of cases of death where the actual cause is not determinable with autopsy, histological or toxicological examinations. In these cases of death, we can consider cardiac dysfunction of unknown origin, in the background of which such a physiologic cardiac insufficiency occurs that cannot be detected with the previously mentioned methods. The dysfunction is possibly associated with a significant change in certain inorganic elements, primarily in the conduction system of the heart. In the absence of published data, our goal was to determine the concentration of inorganic elements in the specialized rhythm determining muscle cell groups in the heart: sinus node (SN), atrioventricular node (AV), septum (SE), left ventricle anterior wall (LVAW). With microwave technology we destroyed the muscle tissue and measured the concentration of ions (Na, Mg, K, Ca, Mn, Fe, Cu, Zn, P, S) using Inductive Completed Plasma Atom Emission Spectrometry (ICP-AES) equipment. Of the 24 cases examined, the average ion concentrations in microgram/g were the following; Sinus: Na 2602 +/- 493, Mg 120 +/- 24, K 1787 +/- 347, Ca 244 +/- 41, Mn 0.129 +/- 0.011, Fe 58 +/- 12, Cu 2.171 +/- 0.46, Zn 10.4 +/- 2.027, P 1147 +/- 227, S 2301 +/- 245; Septum: Na 1452 +/- 315, Mg 243 +/- 56, K 3269 +/- 689, Ca 105 +/- 26, Mn 0.17 +/- 0.05, Fe 74 +/- 16, Cu 3.557 +/- 0.952, Zn 25.75 +/- 8.4, P 2764 +/- 494, S 3001 +/- 523; Av: Na 2614 +/- 517, Mg 242 +/- 40.2, K 2010 +/- 395, Ca 271 +/- 27.3, Mn 0.13 +/- 0.029, Fe 54 +/- 12, Cu 2.369 +/- 0.297, Zn 15 +/- 3.2, P 1625 +/- 291, S 2535 +/- 346; Lvaw: Na 1340 +/- 201, Mg 250 +/- 37, K 3659 +/- 532, Ca 88 +/- 22, Mn 0.175 +/- 0.05, Fe 76 +/- 19, Cu 3.62 +/- 0.58, Zn 27.13 +/- 3.1, P 3025 +/- 441, S 3140 +/- 440.

Adolescent↗
PubMed2000

Evaluation of a Hungarian acaricide original molecule based on its environmental toxicological studies.

The results of the environmental toxicological investigations and their results of a new hungarian acaricide molecule (SZI-121) developed by the CHINOIN were summarized. The toxicological effects of the test item on different ecotoxicological test systems were investigated in the following tests: Bacterium, alga, and plant growth inhibition tests, acute immobilization and 21 days reproduction tests on Daphnia magna, acute fish test, closed bottle test, mobility, aerob degradation and adsorption/desorption tests on three different soils. No toxic effect was found in the bacterium, alga, plant growth inhibition and acute fish tests in the highest concentrations used. In the Daphnia immobilization test 0.14 mg/l LC50 value was established in the concentration range of 0.0128-40 mg/l applied. The test item showed similar characteristics as the reference item during the mobility test in soils, the adsorption/desorption study and the degradation investigations. In order to determine the environmental degradation rate further degradation investigations, as well as the nitrogen mineralization test and the model of concentration change in natural waters were performed.

Acari↗
PubMed2000

Results of the general toxicity and genetic studies of an insecticide intermediate.

Methyl-chrysanthemate is one of the intermediates of pyrethroid type insecticides. The acute toxicity of the test item was investigated in rats after single oral, dermal and inhalation applications. The irritation effect was determined by Draize method. Buehler method was applied to evaluate the sensitization potential of the test item. The mutagenic effect was assessed on Salmonella typhimurium strains. Furthermore metaphase chromosome aberration assay was performed on CHO cell line to check the structural chromosome aberrations.

Animals↗
PubMed2000

Ecotoxicological experiences on Lemna minor test system.

Are plants generally less sensitive to toxicity than aquatic animals as indicated by some authors (1)? The use of phytotoxicity (higher plant) tests as a part of ecotoxicology is relatively underdeveloped. The objective of this study was to compare the results of the OECD Lemna Growth Inhibition Test with other mainly used test systems. Three toxicants were tested applying the Alga Growth Inhibition Test (Seleneastrum capricornutum), the Daphnia Immobilization Test (Daphnia magna) and the MICROTOX-test (Photobacterium phosphoreum). Duckweed plants were found to be sensitive to the chemicals tested, with nearly 100% inhibition of frond production occurring in the highest concentrations. The plants in some samples showed lesions (break up of the colony structure) and loss of green pigments (chlorosis), others showed localized dead tissues (necrosis). In addition to the morphological deviations (appearance) there is a wide range of characteristics to be observed on the test plants: number of fronds, number of plants, biomass, dry weight, mortality, CO2 and O2 exchange, concentration of chlorophyll a and chlorophyll b. It is consistent that the number of fronds is slightly more sensitive than or the same as the number of plants and that the biomass tend to be somewhat more tolerant than those for the number of plants (2). Applying the simplest way of observation, changes in the frond number were recorded. As Lemna minor show a characteristical sensitivity to the different kind of chemicals, it is a promising indicator of aquatic toxicity.

Environmental Monitoring↗
PubMed1997

Efficacy of some pyrethroids against a strain of the rabbit ear mite (Psoroptes cuniculi): an unusual cross-resistance pattern.

An in vitro immersion bioassay was used to compare the efficacy of selected pyrethroids against a deltamethrin-resistant strain of rabbit ear mite (Psoroptes cuniculi). A lack of cross-resistance between bromo (deltamethrin) and chloro analogues (cypermethrin) of alpha-cyano-3-phenoxybenzyl-dihalovinyl-dimethylcyclopropane carboxylate was detected. Whereas deltamethrin proved to be inactive (48-h mortality 21.9% at 1000 mg/kg), each cypermethrin isomer mixture tested, including alpha-cypermethrin [IR(cis) alpha S + 1 S (cis) alpha R] and theta-cypermethrin [1R(trans) alpha S + 1 S (trans) alpha R] and their mixture at a ratio of 4/6, beta-cypermethrin, showed high efficiency (48-h mortality > or = 95% at 1000 mg/kg).

Analysis of Variance↗
PubMed1996

Susceptibility of Hydrotaea aenescens (Wiedemann) (Diptera: Muscidae) to selected insecticides and its importance in integrated fly management.

The doses lethal to 50% of the insects (LD50 values) obtained for a strain of Hydrotaea aenescens (Wiedemann) adults from a layer farm revealed higher sensitivity to 16 insecticides than those recorded for the susceptible WHO/SRS strain of the housefly. Because H. aenescens adults are about half the size of the housefly, the chemical compounds used for adult control may jeopardize the survival of Hydrotaea populations released in animal confinement houses. An efficient and economical combined application of biological and chemical control methods is possible only if the local management conditions and the dissimilar behavior of the adults of the two species are taken into consideration during the use of insecticides. Other suggestions and implications are further discussed.

Animals↗
PubMed1986

A rapid method for the evaluation of nerve conduction blocking compounds.

A simple and easily accessible cockroach nerve preparation is described. Afferent potentials elicited by electric stimulation of the cercus showed remarkable stability, providing a fairly adequate background for pharmacological experimentation. Type I and type II pyrethroids were tested on the nerve preparation, and the results were compared with toxicity data obtained on the same species. Blockade of nerve conduction showed positive correlation (r = 0.804) with lethal effects. The preparation would be useful for determining neuronal point of attack of test compounds and the study of pyrethroids.

Animals↗
PubMed1983

Intrauterine growth retardation: ultrasonic diagnosis.

In 3258 pregnant mothers with ascertained gestational length, 3736 biparietal and transverse thoracic diameters were measured by a rapid screen ultrasound device. The data were processed by computer and the possibilities of detection and typing of intrauterine fetal retardation were examined. Serial measurements performed during pregnancy satisfactorily detected type I or the proportional type. The asymmetrical form, type II, can be distinguished by the Neyman-Pearson method. The decision curves applicable for each gestational week have been computed and are described. They can also be used for determination of the degree of intrauterine wasting.

Computers↗
PubMed1979

Ultrasonic estimation of gestational age and fetal weight.

Ultrasonic fast-scanning analysis was carried out during the 2nd and 3rd trimesters of pregnancy. In 1690 cases biparietal diameter, in 784 chest transverse diameter measurements were done and suitable growth charts constructed for the estimation of gestational time. Both the biparietal and chest transverse diameter values were taken into consideration in 582 cases and the results analysed by mathematical methods. A method has been worked out for the estimation of fetal weight with an absolute standard error of 261 g. On the basis of comparative studies it is suggested that obstetrical teams working with ultrasonic devices should establish their own set of parameters and methods.

Birth Weight↗
PubMed1977

Transverse diameter of the chest and of the heart of infants in the course of physiological cardiorespiratory adaptation.

The morphology of the lungs and heart was analysed in 824 newborn infants with normal cardiorespiratory adaptation. Under normal conditions, the air content of the lungs became satisfactory in the first 6--12 hours and normal in all cases after 24 hours. The values for the transverse diameter of the chest and heart were brought into correlation with birth weight, body length and gestational age. The transverse diameter of the chest and heart did not change during the early postnatal period (between 6--12 hours and 5 days). Both diameters were correlated with birth weight. The closest correlation was found in newborns under 1500 g, a varying one in those between 1500 and 2000 g and a close correlation in the category over 2000 g. The correlation of the two diameters with both length was linear and close, without any difference between the values obtained at different times of examination. A rather loose correlation was found between the transverse diameter of the chest and heart, and gestational age.

Adaptation, Physiological↗