PubMed Health⌕ Search

Biomedical subjects

Z Szántó

Publications and source records attributed to Z Szántó.

11 recordsLinked to original sources
PubMed2004

Mitigation of oxidative injury by classic and delayed ischemic preconditioning prior to small bowel autotransplantation.

Ischemic preconditioning (IPC) has been defined as short periods of ischemia with intermittent reperfusion. IPC induces two phases of protection. We sought to investigate the effects of classic and delayed preconditioning on oxidative stress markers prior to autotransplantation. Total orthotopic intestinal autotransplantation was performed on 18 mongrel dogs in three groups: group I (GI, nonpreconditioned), group II (GII, classic preconditioned), and group III (GIII, delayed preconditioned). In GI 3-hour cold preservation in University of Wisconsin solution was followed by 1 hour of reperfusion. In GII before this procedure the intestine was preconditioned by occlusion of the mesenteric artery with four cycles each of 5 minutes of ischemia and 10 minutes of reperfusion (IPC protocol). In GIII on day 1 the animals underwent the IPC protocol, and autotransplantation was performed on day 2. Oxidative stress parameters included malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD) measurements in tissue samples. Our results showed increased lipid peroxidation with decreased GSH level and SOD activity in GI (control: 254.38 +/- 18.32 IU/g; reperfused: 55.01 +/- 26.40 IU/g; P <.05). In GII MDA was slightly elevated, and the GSH concentration was increased markedly. Furthermore, better preservation of SOD activity was observed at the end of the reperfusion. Meanwhile, in GIII GSH was significantly increased, indicating the activation of the endogenous antioxidant protective system (control: 382.13 +/- 24.22 micromol/L per gram; reperfused: 515.25 +/- 26.36 micromol/L per gram; P <.05). Moreover, SOD surpassed the control activity. Our findings confirmed that both forms of preconditioning mitigate the severity of oxidative stress prior to preservation and autotransplantation. Delayed preconditioning is more effective to protect bowel tissue against oxidative injury.

Animals↗
PubMed2002

Effects of pretreatment with PACAP on the infarct size and functional outcome in rat permanent focal cerebral ischemia.

PACAP exerts neuroprotective effects under various neurotoxic conditions in vitro. In vivo, it reduces brain damage after global and transient focal ischemia. The present study investigated whether PACAP has neuroprotective effects when applied before the onset of permanent ischemia. Rats were given bolus injections of PACAP38 intracerebroventricularly, and then underwent permanent middle cerebral artery occlusion. The results show that 2 microg of PACAP significantly reduced the infarct size measured 12 and 24h after the onset of ischemia. No further reduction was obtained by a 7-day pretreatment. PACAP also ameliorated certain sensorimotor deficits. Our present study provides further evidence for the neuroprotective effects of PACAP, and implies that it might be a promising preventive therapeutic agent in ameliorating ischemic brain damage.

Animals↗
PubMed2001

Traumatic myiasis of geese in Hungary.

Five geese flocks were surveyed to gather data on the prevalence and clinical manifestation of traumatic myiasis and the fly species involved. Myiasis was recorded in all the flocks and the total number of infested geese was 26 (ca. 0.1% of the total numbers). The first cases were observed at the end of May, the last ones in August. Most birds (16/26) were infested in August. Each affected goose had only one lesion, which was located more frequently on the wings (14/26) than on any other body. In seven geese, Wohlfahrtia magnifica (Diptera: Sarcophagidae) was the only myiasis-causing species. In these cases the detransformed mean number of larvae per wound was 18.1 (range 5-40). Lucilia sericata (Diptera: Calliphoridae) was found to be solely responsible for the lesions of 12 birds, with detransformed mean of 94.0 (range 2-893) larvae per goose. The larvae of this species appeared to be generally less invasive than those of W. magnifica, but in three cases they were also deeply embedded in the wounds. In seven geese larvae of both fly species developed together in and around the wounds. With the exception of one lesion, there were more larvae of W. magnifica (detransformed mean of 21.8 with a range of 1-55) than that of L. sericata (detransformed mean of 11.2 with a range of 2-61) in these mixed infections. Predisposing conditions for development of traumatic myiasis in geese included plucking of feathers, other injuries and bacterial infections (e.g. inflammation of the phallus).

Animals↗
PubMed2001

[Monitoring of oxidative stress after experimental small bowel autotransplantation].

The difficulty at transplanting the small bowel mainly is caused by the biology of the intestine. It is highly immunogenic, is one of the most sensitive tissues to ischemia-reperfusion injury. Our aims were to investigate changes of oxygen free radical mediated reactions after autotransplantation at different preservation times and perfusion fluids. Our results prove that this model is feasible to examine ischemia-reperfusion injury in the small intestine. Euro Collins (EC) is a suitable preserving solution for small bowel transplantation. There was no significant lipid peroxidation within the first 6 hours of graft preservation. However superoxide dismutase (SOD) activity was dramatically reduced during reperfusion in the tissues samples. Significant increase of reduced glutathione at the same time can be explained by compensatory mechanism to neutralize increased free radical production.

Animals↗
PubMed2001

[Partial replacement of the trachea with jejunal autograft in the dog].

Extensive lesions of the cervical trachea can occur as a result of malformation, inflammation, tumor disease or trauma. If a short segment of the trachea is resected primary anastomosis may be possible. The problem of how to treat lesions longer than 50% of total tracheal length is still unresolved. The aim of our study was to clarify the possible use and limitations of small bowel interposition for tracheal replacement in veterinary model. We resected 6 cm of the cervical trachea of 5 adult mongrel dogs. Autolog jejunum free flap was used for replacement. The wall of the implant was supported with 5 polytetrafluoroethylene rings placed on the outer surface of the bowel perpendicular to its axis. We performed the surgery in two stages. Intraoperative tracheostomy was necessary in every case. The tracheal tube extended through the whole length of the implant. The survivals, the viability of the graft and complications were examined. The length of survival ranged between 18 h and 72 h. In one case obstruction of the tracheal tube occurred, in 3 cases the micro vessel anastomosis of the graft thrombosed, in one case both complications developed. In our experience use of the small bowel flap was complicated with fatal technical difficulties. The micro vessel anastomosis proved to be highly risky. Further investigations are needed to improve the results with this method.

Animals↗
PubMed2000

Comparative three-dimensional quantitative structure-activity relationship study of safeners and herbicides.

The competitive antagonist hypothesis for safeners and herbicides was investigated by studying the 3D similarity between 28 safener and 20 herbicide molecules in their putative biologically active, low-energy conformations using comparative molecular field analysis (CoMFA). In addition, CoMFA provided information about the structural requirements for the interactions of safeners and herbicides with a proteinaceous component (SafBP) isolated from etiolated corn seedlings. Statistically significant CoMFA models have been developed for the united and separate safener and herbicide molecule sets using retrospective binding affinity data of the ligands measured at the SafBP receptor. The predictive power of the models was characterized by squared cross-validated correlation coefficients (q(2)) of 0.708, 0.564, and 0.4000 for the united safener plus herbicide set, the safener set, and the herbicide set, respectively. The CoMFA results support the competitive antagonist hypothesis between certain types of safeners and herbicides. The findings suggest that structural similarity between these two classes of agrochemicals is a useful guide in the design of new safeners.

Acetamides↗
PubMed1998

Effect of the different factors on the iontophoretic delivery of calcium ions from bentonite.

The calcium content of mud patches used for therapy is very small. Several mineral clays originating from Hungary served as a base material for experiments in order to find a suitable drug for transdermal introduction of calcium ions into the body. The Ca++ transport through the pig skin has been investigated in vitro in diffusion cells applying iontophoresis. Studies of electrical and physicochemical factors acting on the permeation kinetics of in vitro experiments were performed. The utilization of direct current has intensified the Ca++ transport through the pig skin (129.78+/-26. 15 microgram Ca/cm2). On using pulsate currents the amount of the Ca++ penetrating through the skin was 5-10 times higher (283.18+/-16.89 microgram Ca/cm2, 388.71+/-19.90 microgram Ca/cm2) than that of the passive transport (36.22+/-14.20 microgram Ca/cm2). The amount of Ca++ cumulated in the receptor compartment was directly proportional to the amount of bentonite (a natural mineral clay with a large cation exchange capacity) in the donor compartment and to the concentration of Ca++ in the lattice of the applied mineral clay. Therefore, the experiments were carried out on a bentonite previously enriched in Ca++ in its lattice (50 mg Ca/g bentonite). The results of the in vitro studies could open a new field of application in the therapy of osteoporosis or in the use of mineral substances.

Administration, Cutaneous↗