Biomedical subjects

Zsolt Szabó

Publications and source records attributed to Zsolt Szabó.

4 recordsLinked to original sources

PubMed2003

A detailed procedure and dissection guide for the isolation of spiral ganglion cells of the guinea pig for electrophysiological experiments.

In the present study step-by-step instructions are provided for a preparative technique employed for the removal of the spiral ganglion from the inner ear of the guinea pig. Removal of the temporal bone is followed by opening of the bulla and excision of the modiolus. All major steps of the technique are illustrated with photographs. A procedure to obtain surviving, acutely separated spiral ganglion neurones is also described. By this procedure small tissue pieces are removed from the modiolus which contain the spiral ganglion neurones. The tissue fragments then undergo a mild enzyme treatment (collagenase and pronase). After the enzyme exposure, the tissue pieces are gently triturated, and the isolated cells are allowed to settle. Poly-D-lysine ensured the firm attachment of the spiral ganglion cells to the cover-slips. The application of this adhesive coating seemed to be desirable in functional studies when microelectrode techniques and/or rapid exchange of the extracellular solution were employed.

Animals↗

PubMed2003

Activated PMNs lead to oxidative stress on chondrocytes: a study of swine knees.

Using an in vitro model, based on primary cultured chondrocytes, we examined possible oxidative injury caused by activated polymorphonuclear neutrophil granulocytes (PMNs), which are thought to be part of the pathomechanism of hemarthrosis. Chondrocytes were isolated from swine knee joints and divided into three groups. Pure chondrocytes acted as the control population (group I). PMNs from the systemic circulation, and hydrogen peroxide (as an artificial source of reactive oxygen species (ROS)) were added to groups II and III, respectively. All cultures were incubated for 6 hours. After the experiment, lipid membrane degradation by ROS was assessed by monitoring changes in the levels of malondialdehyde (MDA) and 4-hydroxyalkenal contents of the chondrocyte specimens. Changes in the endogenous scavenger status of the chondrocytes were characterized by measuring of reductions in glutathione (GSH) concentration and superoxide dismutase (SOD) activity. Significant increases in MDA/4-hydroxyalkenal levels and SOD activity as well as an expressive reduction in intracellular GSH content were highlighted by comparing the control to the PMN- or H2O2-treated cell populations. These findings confirm previous suggestions that PMN-derived ROS contribute to degradation of cartilage in hemarthrosis.

Aldehydes↗

PubMed2002

Clinical and non-clinical investigations using positron emission tomography, near infrared spectroscopy and transcranial Doppler methods on the neuroprotective drug vinpocetine: a summary of evidences.

Vinpocetine (Cavinton, Gedeon Richter, Budapest) is widely used as a neuroprotective drug in the prevention and treatment of cerebrovascular diseases. Vinpocetine is a potent inhibitor of the voltage-dependent Na(+) channels and a selective inhibitor of the Ca(2+)/caldmoduline-dependent phosphodiesterase 1. The clinical efficacy has been supported by several previous studies. Positron emission tomography (PET) is a powerful method to evaluate the fate, the site of action, the pharmacological and physiological effects of a drug in the brain and other organs. We have demonstrated in monkey that the [11C]-labelled vinpocetine rapidly enters the brain after intravenous (i.v.) injection, the maximal uptake being approximately 5% of the total injected radioactivity. The distribution pattern of vinpocetine in the brain was heterogenous, with the highest uptake in the thalamus, basal ganglia and visual cortex. These findings were confirmed in healthy humans, where the i.v. administered [11C]-labelled vinpocetine had a similar distribution pattern. The highest uptake in the brain was 3.71% of the total administered radioactivity. Quite recently, we have shown that [11C]-labelled vinpocetine administered orally to healthy human volunteers also rapidly appears in the brain and shows a similar distribution pattern, the highest uptake being 0.71% of the total administered radioactivity. In two separate sets of clinical studies where chronic ischaemic post-stroke patients were either treated with a single infusion (Study 1) or with daily vinpocetine infusion for 2 weeks (Study 2), we have shown that vinpocetine increases the regional cerebral glucose uptake and to a certain extent glucose metabolism in the so-called peri-stroke region as well as in the relatively intact brain tissue. The 2-week-long treatment also increased the regional cerebral blood flow (CBF) especially in the thalamus, basal ganglia and visual cortex of the nonsymptomatic hemisphere. We have demonstrated the cerebral perfusion-enhancing and parenchymal oxygen extraction-increasing effects of vinpocetine in subacute ischaemic stroke patients by near infrared spectroscopy (NIRS) and transcranial Doppler (TCD) methods.

Aged↗

PubMed2002

[Postoperative vomiting].

INTRODUCTION: Nausea and vomiting following general anaesthesia are among the most frequent adverse reactions causing complications, the relief of which is an absolute demand. 5-HT3 receptor antagonists, such as ondansetron, belonging to the latest class of antiemetics were launched more than a decade ago. PATIENTS/METHODS: Efficacy and tolerability of ondansetron injection in prevention of postoperative nausea and vomiting were investigated in a prospective, randomised, double-blind, placebo controlled, three-armed clinical study in 148 patients undergoing laparoscopic cholecystectomy. Moreover the authors also investigated the effect of timing of dosing, i.e. whether the administration of antiemetic drug before starting anaesthesia has any advantage comparing its use at the end of operation. RESULTS: While using a standard surgical and anaesthesia method vomiting after laparoscopic cholecystectomy occurred in a frequency of 44.7% of the patients in the placebo group, whereas the figures decreased significantly after administration of 4 mg ondansetron at the end (28.9%) or before (25.5%) anaesthesia. Inclusively the frequency of severe cases decreased from 19.2% of control group up to 8.9% and 4.3% in the active groups, respectively. CONCLUSIONS: Intravenous administration of 4 mg ondansetron effectively reduces vomiting occurring in more than 40% of patients after laparoscopic cholecystectomy, especially the frequency of severe cases, and mainly if administered before operation. The preparation is safe; no clinical or laboratory adverse reactions, complications have been observed in the studied patients.

Adult↗