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Biomedical subjects

S Szabó

Publications and source records attributed to S Szabó.

At least 19 recordsLinked to original sources
PubMed2006

Effect of sevoflurane on cerebral blood flow and cerebrovascular resistance at surgical level of anaesthesia: a transcranial Doppler study.

BACKGROUND AND OBJECTIVE: It is widely accepted that sevoflurane affects cerebral circulation, but there are uncertainities regarding the magnitude of its effect. The aim of the present work was to assess the effect of sevoflurane on the cerebral circulation at surgical levels of anaesthesia. METHODS: Twenty patients undergoing elective lumbar discectomies were investigated. Anaesthesia was induced with propofol and maintained with sevoflurane. The level of surgical anaesthesia was determined by bispectral index, the target level was 45-55. Transcranial Doppler (TCD) measurement was performed before induction and after reaching the surgical level of anaesthesia. Besides routine parameters (middle cerebral artery mean blood flow velocity (MCAV) and pulsatility index (PI)) derived parameters (estimated cerebral perfusion pressure (eCPP), cerebral blood flow index (CBFI) and resistance area product (RAP)) were calculated by taking changes of mean arterial pressure also into account. RESULTS: MCAV decreased from 54.1 +/- 13.3 to 43.7 +/- 18.5 cm s-1, P < 0.01 and PI increased from 0.79 +/- 0.2 to 0.92 +/- 0.2, P < 0.01 after reaching the surgical level of anaesthesia. As a result eCPP decreased by 18.2%, CBFI by 25.5% and RAP increased by 15% respectively. CONCLUSIONS: Our data indicate a vasodilatory effect of sevoflurane at surgical level of anaesthesia on large cerebral vessels or a vasoconstriction of the resistance arterioles likely caused by decreased brain metabolism.

Adult↗
PubMed2001

Configuration and racemization determination of cysteine residues in peptides by chiral derivatization and HPLC: application to oxytocin peptides.

An improved RP-HPLC method was developed for the determination of the configuration and stereochemical purity of cysteine residues in peptides. The method consists of oxidation of cysteine and cystine residues to cysteic acid, followed by hydrolysis and pre-column chiral derivatization with Val-Marfey's reagent.

Chromatography, High Pressure Liquid↗
PubMed2000

[Acute gastrointestinal bleeding caused by a rare, benign tumor of the duodenum (gangliocytic paraganglioma)].

Diagnosis and treatment of massive gastrointestinal bleeding is sometimes very difficult problem in a surgical unit. Authors present a case of a 40 years old female with an atypical source of upper gastrointestinal bleeding. The origin of the bleeding was detected only by intraoperative enteroscopy. The source of the bleeding was a very rare benign tumour of the duodenum (Gangliocytic paraganglioma) which involved the papilla of Vater. During the operation resection of the pedunculated tumour was carried out, with choledochal--and Wirsungoplastyc, associated with external drainage of these ducts. According to the literature in preoperative diagnosis of this rare tumour endoscopy, angiography, and EUS are very useful. In case of malignancy, metastases radical operation-pancreatoduodenectomy--is indicated.

Acute Disease↗
PubMed1997

Correlation between central somatosensory conduction time, blood flow velocity, and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

In this retrospective study of 67 aneurysmal patients, the predictive role of central conduction time (CCT) on vasospasm occurrence evaluated by means of transcranial Doppler sonography (TCD) and the correlation of CCT to blood flow velocity measured simultaneously in postoperative course were studied. Data about the clinical state of patients at the time of admission (Hunt Hess scale), severity of subarachnoidal hemorrhage on initial CT scan (Fisher grade), timing of surgery (acute or delayed), outcome (Glasgow Outcome Scale), severity of vasospasm graded by highest mean blood flow velocity (BFV) during the entire clinical course and CCT values measured at admission (preoperatively), then postoperatively (one day after surgery) and simultaneously with later TCD investigations were collected from the files. Interhemispheric difference of CCT was also calculated. The results showed that CCT at admission was not predictive for vasospasm. CCT measured either at admission or on the first postoperative day did not differ significantly in the different grades of vasospasm. Similar results were obtained in the acute and in the late operated group of patients. The results also suggest that increased CCT and interhemispheric difference at the time of admission indicate a worse prognosis, but this can be related to higher surgical risk rather than to a higher incidence of late ischemic deterioration. Simultaneous CCT and TCD examinations demonstrated that coincident and statistically significant (p < 0.01) increase of actual CCT (6.7 msec) was found only in the severe grade of vasospasm (BFV 200 cm/s). The authors discuss the role of CCT and TCD monitoring in the management of aneurysmal subarachnoid hemorrhage.

Adult↗
PubMed1995

[Role of endogenous basic fibroblast growth factor in experimental duodenal ulcer].

Authors investigated the role of endogenous bFGF in the development of experimental duodenal ulcer induced by cysteamine. The changes in endogenous bFGF in duodenum were examined by immunohistochemical method in the early stages of ulceration. A significant decrease was found in the immunoreactivity of bFGF in rat duodenal mucosa 12 and 24 hr after the administration of the duodenal ulcerogen cysteamine. Thus, in addition to being a novel potent pharmacologic agent, bFGF may play a pathophysiologic role in ulcer pathogenesis and healing.

Animals↗
PubMed1995

[The effect of thrombocyte-derived growth factor on experimental inflammatory bowel disease].

The role of Platelet-Derived Growth Factor (PDGF) was investigated in treatment of experimental inflammatory bowel disease (IBD) in animal models. A new model of IBD induced by the sulfhydryl (SH) alkylator iodoacetamide revealed that the most appropriate concentration of iodoacetamide is 6% given intracolonically once. Daily treatment with PDGF dose-dependently accelerated the healing of colonic erosions, ulcers and inflammation.

Animals↗
PubMed1994

LB-145 a new radioactive isotope eliminating product with high selectivity.

LB-145 is a macrocyclic ligand, which forms, 200 times more stable complex with Stroncium (Sr) ions, than with calcium ones. The product is not toxic, it has no effect on circulation, respiratory system. 85,90Sr and 144Ce were given oral, i.p., s.c. or by inhalation, LB-145 either prophylactic or 30 (60) minutes after the radiointoxication i.v. or i.p. to the animals. The isotope contents of the organism were measured by whole body autoradiography, liquid scintillation, or by NK 350 ratemeter. One injection given prophylactic inhibited the incorporation of isotopes into the organism, within 24 hours after radiointoxication 75-80% of the isotopes were excreted by urine and faeces on the first day, 90-95% excreted on the first week. Also the isotope contents of femur and scissors were mobilised. The suggested human dose-0.5 g/70 kg bw-can be life-saving antihavaric injection.

Animals↗
PubMed1994

New 4-arylaminopiperidines with antihypoxic and anticonvulsive activity.

Several new bioanalogues of (+/-)-N-methyl-N-(1-[3-(4-fluorophenoxy)-2-hydroxy-propyl]piperidin++ +-4-yl) benzothiazol-2-amine (1, sabeluzole, CAS 104383-17-7) were prepared by reacting 1,2-epoxy-3-aryloxypropanes with 4-arylaminopiperidines. Some of these derivatives showed enhanced activity in the potassium cyanide hypoxia test and in the pentetrazol convulsion test in mice compared to 1.

Animals↗
PubMed1992

[Successful electroconvulsive treatment of a schizophrenic patient suffering from severe hemophilia A].

Experiences obtained with the electroconvulsive treatment of a schizophrenic patient suffering from severe haemophilia A are reported. No haemorrhagic complications were observed. According to our experiences electroconvulsive therapy can be applied also in severe haemophilia A if satisfactory replacement therapy can be ensured. Similar case has not been found in the literature.

Adult↗
PubMed1991

[Intracranial pressure increase and changes in cerebrovascular circulation, associated with brain death, studied by transcranial Doppler sonography].

Blood flow velocity of 24 patients in state of the brain death were examined by transcranial Doppler sonography. Authors expound the characteristic velocity-pulse graphs recorded in progressively increasing intracranial pressure and their chronology as well. The different forms of the oscillating flow and their successive development are described. The oscillating flow, the systolic spikes and the so called "zero Flow" are the transcranial Doppler signs of the ceased cerebral blood flow, and these signs can be used as one of the evidence of the brain death.

Adolescent↗
PubMed1989

[Detection of increased intracranial pressure by transcranial Doppler sonography in infants].

The value of transcranial Doppler sonography is demonstrated in two infants with an elevation of intracranial pressure (ICP). One of them suffered from hydrocephalus and ICP increased because of her VP shunt-insufficiency. In the other case status epilepticus caused brain oedema and a rise in intracranial pressure. In both cases, transcranial Doppler sonography showed a decrease in blood flow (CBF) velocity and an increase in the Pourcelot index in the middle cerebral artery. Quick or gradual reduction of the ICP led to an increase in CBF velocity and a decrease in the Pourcelot index. On the basis of experiences of the authors, transcranial Doppler sonography is a valuable method of verifying the elevation of ICP. It is suitable for measuring the effect of treatment necessitated by the elevation of ICP. The method is non-invasive, quick and it can be freely repeated. Therefore it is applicable for monitoring the dynamic of ICP.

Age Factors↗
PubMed1989

[Transcranial Doppler sonography, a new non-invasive method for the study of cerebrovascular circulation].

Transcranial Doppler Sonography. Authors publish the experiences gained by 2300 examinations with Transcranial Doppler Sonography (TDS) which is a new, noninvasive ultrasound method to examine cerebral blood flow velocity in the basal arteries. The theoretical ground and the technique of the investigation is detailed. Mean values of blood flow velocity in the middle cerebral artery of 88 healthy volunteers in different age groups are reported. Authors stress on the numerous advantages of the utilization of this technique. Different pathological alterations of blood flow velocity and characteristic types of velocity-pulse figure are accounted. At last illustrative case reports proving the importance of TDS in different pathological states are presented.

Adult↗
PubMed1989

Selective decrease of duodenal phosphoprotein phosphatase activity is a general property of duodenal ulcerogens.

A phosphoprotein phosphatase (PPPase) is inhibited in rat duodenal mucosal cells very early after a single s. c. injection of the duodenal ulcerogens cysteamine, propionitrile and mepirizole. The effect seems to be independent of their effects on gastric acid secretion and on duodenal suppression of alkaline secretion. The enzyme inhibition is dose- and time-dependent under in vivo conditions. The inhibition of the PPPase activity is enzyme-selective at the level of mucosal cells in the duodenum. Under in vitro conditions, none of the duodenal ulcerogens inhibited PPPase activity. The results indicate that the effect of the ulcerogens on PPPase activity is probably exerted indirectly. When given simultaneously in vivo, propionitrile attenuated the inhibitory effects of cysteamine on the PPPase activity. However, both propionitrile and cysteamine potentiated the effect of mepirizole on PPPase depletion. These data indicate that cysteamine and propionitrile may act through the same mechanism when depleting PPPase activity. The mechanism of the decrease of duodenal protein phosphatase activity by mepirizole is probably different from the other duodenal ulcerogens.

Animals↗
PubMed1989

Vasospasm after head injury studied by transcranial Doppler sonography.

During the past 2 years cerebral blood flow velocity was measured serially first of all in the middle cerebral arteries and in the bifurcation of the carotid arteries, less frequently in the other basal arteries by transcranial Doppler sonography in 36 head injured patients selected from 87 cerebral contusions and intracranial haematomas. Raised flow velocity referring to cerebral vasospasm was observed in 14 (40%) of 36 cases. Vasospasm developed between the 2nd and 8th days in the basal arteries, never on the first day. It was classified as slight (over 120 cm/sec) and sever (over 160 cm/sec) in the case of vasospasm lasting for several days. Development of vasospasm could be justified in 6 from 14 control angiographies. Authors' observations are compared with some literary data of traumatic vasospasm. The theoretical significance and practical usefulness of transcranial Doppler sonography in the study and follow up of the blood flow of the injured brain, especially in traumatic vasospasm, are emphasized.

Adolescent↗
PubMed1989

Critical and timely review of the concept of gastric cytoprotection.

Gastric cytoprotection is a concept or phenomenon, and not a single magic mechanism of action of unusual compounds. It refers to prevention of acute hemorrhagic erosions where the superficial epithelial cells are not directly protected but are rapidly replaced by restitution in microvascular injury in subepithelial capillaries is prevented or diminished and blood flow is maintained. This gastroprotection achieved by prostaglandins (PG), sulfhydryls (SH) and non-SH antioxidants is thus real but relative by target, mechanisms and in time. PG and SH are the only two chemical entities with both pharmacologic and biochemical relevance, i. e., endogenous concentrations of PG and SH derivatives may be measured biochemically and correlated with the degree of gastroprotection. Despite differences in the chemical mechanisms of action (e. g., SH unlike PG scavenge free radicals and may directly influence SH-sensitive receptors, enzymes and membrane permeability), the structural and functional targets for both groups of compounds are essentially the same: prevention or reduction of microvascular injury in subepithelial capillaries, maintenance of blood flow which allows the energy-requiring rapid epithelial restitution to repair the superficial epithelial defect. This reductionist, critical and mechanistic overview highlights the recent developments and the persisting problems in study design, definitions and interpretation of results as well as some critical questions related to the concept of gastric cytoprotection.

Animals↗
PubMed1984

Role of sulfhydryls and early vascular lesions in gastric mucosal injury.

This paper reviews the recently discovered role of sulfhydryls and early vascular injury in the pathogenesis of acute gastric mucosal injury. In the rat ethanol caused a dose-dependent decrease in nonprotein sulfhydryl concentration in the gastric mucosa within 1-5 min following an intragastric dose. These biochemical changes were accompanied by increased vascular permeability in the glandular stomach as revealed by the measurement of extravasated Evans blue injected i.v. prior to the administration of ethanol. Morphologic evidence of vascular injury was provided by labelling of damaged blood vessels in the stomach following the i.v. administration of colloidal particles in the form of india ink or monastral blue. The functional and structural damage to capillaries and venules in the glandular stomach was also maximal within 1-6 min after 1 ml of 75 or 100% ethanol given orally. Pretreatment with sulfhydryl (SH) containing drugs (e.g., L-cysteine, N-acetyl-L-cysteine, cysteamine, dimercaprol) or prostaglandin (PG) F2 beta prevented the ethanol-induced increase in vascular permeability, the labelling of blood vessels with vascular tracers, and the subsequent haemorrhagic erosions. The desquamation of superficial epithelial cells, however, was not markedly modified by either SH or PG compounds. This organoprotective effect of SH and PG drugs was virtually counteracted in adrenalectomized rats that exhibited "vascular fragility". Glucocorticoid treatment restored the response of adrenalectomized animals. Thus, a SH- and glucocorticoid-sensitive early vascular injury seems to be of major significance in the pathogenesis of haemorrhagic gastric erosions and SH-containing compounds represent a new group of cytoprotective or organoprotective agents.

Animals↗