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001-es BibID:BIBFORM046876
Első szerző:Berényi Ervin (radiológus)
Cím:Water Content and Proton Magnetic Resonance Relaxation Times of the Brain in Newborn Rabbits / Berényi Ervin, Repa Imre, Bogner Péter, Dóczi Tamás, Sulyok Endre
Dátum:1998
ISSN:0031-3998
Megjegyzések:The present study, using proton nuclear magnetic resonance relaxation (H1 NMR) measurements, was undertaken to quantitate water fractions with different mobility in the brain tissue obtained form New Zealand White rabbit pups. Serial studies were carried out at the postnatal age of 0-1, 24, 48, 72, and 96 h in pups nursed with their mothers and suckling ad libitum (group I) and in those pups separated from their mothers and completely withheld from suckling (group II). Tissue water content (desiccation method) and T1 and T2 relaxation times (H1 NMR method) were measured. Free, loosely bound, and tightly bound water fractions were calculated by applying multicomponent fits of the T2 relaxation curves. It was demonstrated that brain water content and T1 and T2 relaxation times did not change with age in the suckling pups. In pups withheld from suckling brain water decreased from 89.4 +/- 0.5% at birth to 87.7 +/- 0.1% at the age of 96 h (p < 0.05), T1 remained unchanged, and there was a significant fall in T2 by the age of 72 h (188 +/- 12 versus 178 +/- 4 ms, p < 0.05) and 96 h (171 +/- 6 ms, p < 0.01). Partition of brain water into bound and free fractions as derived from biexponential fits of T2 decay curve showed that the percent contribution of bound water fraction in pups of group I fell progressively from 61% at birth to 3% at the age of 72-96 h (p < 0.05). This fall was accelerated by the complete deprival of fluid intake, and the level of about 4% could be attained as early as the age of 24 h. Triexponential analysis of T2 relaxation curves revealed that the loosely bound fraction (middle component) predominated over the free (slow component) and the tightly bound (fast component) water fractions. In response to withholding fluid intake, the free water fraction increased 4-fold at the expense of tightly bound brain water. It is concluded that the majority of neonatal brain water is motion-constrained. The free, the loosely bound, and the tightly bound water fractions appear to be interrelated; from the brain water store water can be released to supply free water for volume regulation.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Pediatric Research. - 43 : 3 (1998), p. 421-425. -
További szerzők:Repa Imre (1950-) (radiológus) Bogner Péter (1963-) (radiológus) Dóczi Tamás Sulyok Endre
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DOI
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2.

001-es BibID:BIBFORM016932
035-os BibID:(WoS)A1996UN55500026 (Scopus)0029943452
Első szerző:Berényi Ervin (radiológus)
Cím:Postnatal changes in water content and proton magnetic resonance relaxation times in newborn rabbit tissues / Berényi E., Szendrö Z., Rózsahegyi P., Bogner P., Sulyok E.
Dátum:1996
ISSN:0031-3998
Megjegyzések:In the present study, using proton nuclear magnetic resonancerelaxation (H-1 NMR) measurements, an attempt was made to quantitatewater fractions with different mobility in the skin, skeletal muscle,and liver tissues obtained from New Zealand white rabbit pups. Serialstudies were carried out at the postnatal age of 0-1, 24, 48, and 72 hin pups nursed with their mothers and suckling ad libitum (group I) andin those pups separated from their mothers and completely withheld fromsuckling (group II). Tissue water content (desiccation method) and T-1and T-2 relaxation times (H-1 NMR method) were measured. Free. looselybound, and tightly bound water fractions were calculated by applyingmulticomponent fits of the T-2 relaxation curves. It was demonstratedthat skin water content and T-1 and T-2 relaxation times decreased withage (p < 0.01), the decrease in T-2 proved to be more pronounced ingroup II than in group I (p < 0.05). Muscle and liver water, and T-1and T-2 relaxation times did not change with age in the suckling pups.In response to withholding fluid intake muscle water remained constant,liver water increased paradoxically (p < 0.05), T-1 relaxation timeshowed no consistent change in either tissues, whereas T-2 relaxationtime decreased significantly (muscle, p < 0.01) or tended to decrease(liver, p < 0.06). Using biexponential analysis fast and slowcomponents of T-2 relaxation curve could be distinguished thataccounted for 42-47%, 50-57%, and 34-40% of total tissue water in theskin, skeletal muscle, and liver, respectively, regardless of age andfluid intake. Triexponential fits of the T-2 relaxation curve madepossible the further partition of tissue water into tightly bound (fastcomponent), loosely bound (middle component), and free (slow component)water fractions. In all tissues studied, loosely bound fractionpredominated (skin, 48-64%; muscle, 54-65%; liver, 45-63%), followed bythe free (skin, 26-45%; muscle, 23-32%; liver, 20-25%) and the tightlybound water fraction (skin, 6-14%; muscle, 10-16%; liver, 14-33%).Postnatal age and fluid intake had no apparent influence on thispattern of distribution. It is concluded that the majority of neonataltissue water is motion-constrained. The free, the loosely bound, andthe tightly bound water fractions appear to be interrelated anddependent on age, fluid intake, the tissues studied, and theirhydration.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Pediatric Research. - 39 : 6 (1996), p. 1091-1098. -
További szerzők:Szendrö Z. Rózsahegyi P. Bogner Péter (1963-) (radiológus) Sulyok Endre
Internet cím:DOI
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3.

001-es BibID:BIBFORM016927
035-os BibID:(WoS)000089532600022 (Scopus)0033799578
Első szerző:Sedin, Gunna
Cím:Lung water and proton magnetic resonance relaxation in preterm and termrabbit pups : their relation to tissue hyaluronan / Sedin G., Bogner P., Berényi E., Repa I., Nyúl Z., Sulyok E.
Dátum:2000
ISSN:0031-3998
Megjegyzések:The present study was performed to investigate simultaneously totallung water, T-1 and T-2 relaxation times, and hyaluronan (HA) inpreterm and term rabbits. Attempts were also made to establish therelationship of HA to total lung water and to T-2-derived motionallydistinct water fractions. Experiments were performed in fetal Pannonwhite rabbit pups at gestational ages of 25, 27, 29, and 31 d and at apostnatal age of 4 d. Lung tissue water content (desiccation method),T-1 and T-2 relaxation times (H-1-NMR method), and HA concentration(radioassay) were measured, and free and bound water fractions werecalculated by using multicomponent fits of the T-2 relaxation curves.Lung water content and T-1 and T-2 relaxation times were highest at agestational age of 27 d and then declined steadily during the wholestudy period. Similar trends and time courses were seen for the fastand slow components of the T-2 relaxation curve. The T-2-derived freewater fraction remained unchanged at a gestational age of 25-29 d(similar to 67%), but increased progressively to a value of 78.5 +/-7.9% at 31 d (p < 0.001) and to 83.4 +/- 9.4% at the postnatal age of 4d (p < 0.01), Opposite changes occurred in the bound water fraction.Lung HA concentration decreased with advancing gestation from 870.8 +/-205.2 mu g/g dry weight at 25 d to 162.6 +/- 32.4 mu g/g dry weight at31 d (p < 0.001), but it was increased 2-fold postnatally, EIAcorrelated positively with total lung water (r = 0.39; p < 0.001) butnot with the bound water fraction. It is suggested that the physiologiclung dehydration is associated with macromolecule-relatedreorganization of lung water and that the role of IIA in this processneeds to be further investigated.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Pediatric Research. - 48 : 4 (2000), p. 554-559. -
További szerzők:Bogner Péter (1963-) (radiológus) Berényi Ervin (1964-) (radiológus) Repa Imre (1950-) (radiológus) Nyúl Zoltán Sulyok Endre
Internet cím:DOI
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4.

001-es BibID:BIBFORM016928
035-os BibID:(WoS)000082752600015 (Scopus)0344069638
Első szerző:Vajda Z.
Cím:Brain adaptation to water loading in rabbits as assessed by NMR relaxometry / Vajda Z., Berényi E., Bogner P., Repa I., Dóczi T., Sulyok E.
Dátum:1999
ISSN:0031-3998
Megjegyzések:The present study was undertaken to investigate the cerebral adaptationto hypoosmolar stress in adult Pannon white rabbits by applying protonnuclear magnetic resonance relaxometry. Progressive hyponatremia wasinduced by combined administration of hypotonic dextrose in water and8-deamino-arginine vasopressin over a hydration period of 3, 24, and 48h. Each group comprised five animals. After completing the hydrationprotocols, brood was taken to determine plasma osmolality (freezingpoint depression) and sodium concentration (ion-selective electrode)and, at about the same time, T-2-weighted images were made. After thein vivo measurements, the animals were killed and brain tissue sampleswere obtained to measure water content (desiccation method) and T-1 andT-2 relaxation times (proton nuclear magnetic resonance method). Freeand bound water fractions were calculated by using multicomponent fitsof the T-2 relaxation curves. It was shown that brain water content andT-1 relaxation time remained unchanged despite the progressinghyponatremia. By contrast, T-2 relaxation time increased steadily fromthe control value of 100.2 +/- 7.7 ms to attain its maximum of 107.5+/- 8.5 ms (p < 0.05) after 48 h of hydration. Using biexponentialanalysis, fast and slow components of the T-2 relaxation curve could bedistinguished that corresponded to the bound (T-21) and free (T-22)water fractions. In response to hyponatremia, the bound water fractionwas markedly depressed from 6.5 +/- 3.0% to 3.6 +/- 0.9% (3 h, p <0.05) and 3.9 +/- 0.8% (24 h, p < 0.05): then it approached the initialvalue of 5.3 +/- 2.5% by the end of the hydration period of 48 h. It isconcluded that restructuring of brain water is a contributory factor tothe successful adaptation to hypotonic environment.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Megjelenés:Pediatric Research. - 46 : 4 (1999), p. 450-454. -
További szerzők:Berényi Ervin (1964-) (radiológus) Bogner Péter (1963-) (radiológus) Repa Imre (1950-) (radiológus) Dóczi Tamás Sulyok Endre
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