Biomedical subjects

I Furka

Publications and source records attributed to I Furka.

At least 37 records · Page 2Linked to original sources

PubMed1998

Effect of omental angiogenic lipid factor on revascularization of autotransplanted spleen in dogs.

Since the turn of the century, studies have been carried out showing that the omentum contains a factor which enhances revascularization of ischemic tissues. This study was conducted for a period of 3 months and was designed to evaluate the effect of an omental lipid fraction on neovascularization of autotransplanted spleen chips in dogs. Twelve dogs underwent splenectomy and autotransplantation of 5 splenic chips into an omental pouch. In 4 dogs, the splenic chips were immersed in omental angiogenic lipid factor (OAF), while on another 4 dogs, an intramuscular injection of 4 cm3 of OAF was given each day for 7 days postoperatively. A further 4 dogs were not given any of the above treatments (control group). Serial angiographies and histologic examinations demonstrated better neovascularization and regeneration of the transplanted spleen in the dogs from the immersion plus injection group. These data suggest that the omental lipid fraction contains a factor which induces a better regeneration of splenic transplants.

Angiogenesis Inducing Agents↗

PubMed1997

Continuous monitoring of the partial pressure of oxygen in cerebral venous blood.

OBJECTIVE: Clinical oxygen monitoring in the injured brain is somewhat difficult. However, ischemia is one of the major factors responsible for secondary tissue damage after head injury or subarachnoid hemorrhage. Therefore, the aim of the present study was to investigate the value of continuously monitoring the partial pressure of oxygen in cerebral venous blood (PcvO2) during changes in intracranial pressure (ICP). METHODS: In eight domestic pigs with Clark type probes placed in the posterior third of the superior sagittal sinus, PcvO2 was continuously registered while ICP was stepwise elevated by an inflatable balloon placed below the tentorium. Arterial blood pressure was continuously monitored, cerebral perfusion pressure (CPP) was calculated, and arterial partial carbon dioxide pressure and partial pressure of oxygen were registered intermittently. RESULTS: The mean intraparenchymal ICP before the start of balloon inflation was 5 +/- 1 mm Hg, the mean CPP was 80 +/- 15 mm Hg, and the mean PcvO2 was 36 +/- 3 mm Hg. At maximum ICP elevation, CPP decreased to 20 +/- 12 mm Hg, PcvO2 decreased to 10 +/- 6 mm Hg, and ICP increased to 90 +/- 10 mm Hg. Strong linear correlations between ICP and PcvO2 and between CPP and PcvO2 were revealed, and mean correlation coefficients of 0.89 for ICP/PcvO2 and 0.73 for CPP/PcvO2 were calculated. CONCLUSION: The present study demonstrates that polarographic PcvO2 monitoring in the superior sagittal sinus is a reliable method for the early detection of reduced CPP during ICP elevation. This technique is capable of registering the global oxygen supply and oxygen consumption of the brain. It seems superior to jugular venous oxymetry and is better suited for clinical use because of a somewhat low artifact susceptibility.

Animals↗

PubMed1997

Why the internal mammary artery is an ideal graft for myocardial revascularisation? (an experimental model with omentoplasty).

Ten dogs underwent coronary artery bypass grafting through a right thoracotomy. Free internal mammary artery grafts (IMA) was used for aortocoronary bypass to right coronary artery (RCA) without temporary cardiopulmonary bypass. In upper median laparotomy approach, mobilization and lengthening of the omentum was performed through the retrosternal part of the diaphragm. An epiploic muff was effectuated surrounding the IMA graft. After three months the animals were sacrificed and the grafts folded by omentum were used for microscopical study. The histological evaluation has shown that the omentum has formed a new adventitia around the graft. In the new-formed adventitia, newly formed vessels can be found and these are grouped around the adventitia-media border zone, very rarely penetrating into the external layer of the media. This graft-omentoplasty offer a good experimental model which facilitates to investigate in vivo the blood supply needed by free IMA grafts through the adventitia in experimental conditions. The biological mechanism of angiogenesis in graft wall can be investigate as well.

Animals↗

PubMed1997

Late epigastric incisional hernias following laparoscopic cholecystectomy.

By the introduction of laparoscopic cholecystectomy a new "gold standard" procedure became a routinely performed operation in the field of biliary tract surgery. Thus, the incision related early and late complications are thought to diminish, especially the formation of incisional hernias. Five patients had been referred to our department suffering from chronic incisional hernias following laparoscopic cholecystectomy. All of the hernias were located to the site of the epigastric trocar. The contents of the hernias proved to be omentum. The documentation's of the laparoscopic cholecystectomies revealed the extraction of thick walled gallbladders that contain large stones, and the wounds through which the extraction was performed had not been closed. Taking into consideration the fact of the "Chimney Effect" caused by the desufflation of the pneumoperitoneum at the end of the laparoscopic operation, bowel or omentum can easily escape through the relatively large wound formed during the extraction of the gallbladder, resulting in the formation of incisional hernias. This can be avoided by the complete desufflation and the prompt closure of the wound.

Abdominal Muscles↗

PubMed1997

Comparison between continuous brain tissue measurement and cerebrovenous measurement of pO2, pCO2 and pH in a porcine intracranial pressure model.

Simultaneous oxygen measurements in brain tissue (p(ti)O2) and hemoglobin saturation measurement in cerebrovenous blood in patients after severe head injury have shown different results regarding the comparability of the findings in respect to CPP and ICP. This is contrast to theoretical expectations. The aim of this study was to compare continuous ptiO2 measurement with oxygen partial pressure measurement in sagittal sinus (pO2cv) during simultaneously performance in an animal intracranial pressure model. For continuous measurement we used a newly available multisensor probe. We placed a Paratrend 7 probe (BSL, High Wycombe, UK) in the left frontoparietal white matter and measured ptiO2, pCO2 (ptiCO2) pH (pHti) and temperature (t(ti)) while simultaneously measuring these parameters (pcvO2, pcvCO2, pHcv, tcv) in the sagittal sinus in 9 pigs under general anaesthesia. A fogarty balloon catheter was placed supracerebellar infratentorial and inflated stepwise in order to increase ICP. The baseline levels of pO2ti, pCO2ti und pHti in the non-injured brain tissue showed a more extended heterogeneity compared to the findings in cerebrovenous blood. Both, pO2ti and pO2cv were significant correlated to the CPP decrease. In both measurement compartments pCO2 was inverse correlated to the course of CPP and seems the course of pH mainly to determine. p(ti)O2 as well as p(cv)O2 showed a close correlation to the CPP course and have proven to be qualified to indicate metabolic information about the relation of cerebral blood flow and metabolic cerebral demands. The measurement of CO2 tension in both measurement compartments shows a distinct heterogeneity of the absolute values and the results are only weak correlated to CPP. Metabolic influence on this parameter could not be revealed in the used experimental approach.

Animals↗

PubMed1997

Details of teaching, learning and training in laparoscopic surgery.

The authors discuss the specific details of teaching, learning and training in laparoscopy in 6 main sections, on the basis of their experience gained through basic and advanced courses held for approximately 480 participants at the courses organised at the Department of Experimental Surgery of the University Medical School of Debrecen, between 1989 and 1996. The 6 section cover the following: 1. Why these courses are needed? 2. Who should participate in them? 3. When courses should be held (continuously for beginners, at an appointed time for advanced participants, and chances for training should be provided at any time, according to demand) 4. What should be taught? 5. Where teaching and training should take place (surgical learning/training centres) and 6. What methods of teaching should be used.

Animals↗

PubMed1997

Protection of the renal artery in nephron-sparing surgery. I. Pathomorphological study.

It is necessary to clamp the renal artery for some time in renal surgery to preserve the organ. Not only the renal parenchyma but also the wall of the clamped renal artery may be damaged due to known ischaemic-reperfusion causes. Regional venous renal hypothermia induced by intracellular solutions (Sacks II, Euro-Collins) could provide protection against damage of the vessel wall caused by reperfusion or clamping in our experiments, in cases of clamping for 30 minutes, probably because it also ensured the cooling of the surface of the vessel wall. Similar vasoprotective effect could be achieved by systematic antioxidant treatment (MTDQ-DS) and regional renal hypothermia given in combination. Harmful effects of 45-minute clamping could be best avoided by applying antioxidant treatment alone. While there were no significant morphological changes in the renal arteries the persistent endothelial damage may trigger further complications like renal ischaemic condition.

Animals↗

PubMed1997

Protection of the renal artery in nephron-sparing surgery. II. Arterial contractility investigations.

It has been well known that reperfusion following ischaemia may cause functional and structural damage to not only the organ involved but also the blood vessels supplying that organ. As in organ-sparing renal surgery it is inevitable to clamp the renal artery for some time, it is expected that reperfusion, following the removing of clamping, causes structural changes in the vessel wall which may result in a decrease in arterial function. In our model experiments on animals, the left renal arteries were atraumatically clamped for 30, 45 and 60 minutes. Simultaneously with clamping, perfusion regional renal venous cooling was applied to some of the animals, together with nephrotomy. In some cases cooling was performed in combination with antioxidant treatment. On the 3rd postoperative day renal arteries from both sides were removed, the right, intact ones serving as control. Noradrenaline dose effect curves characterizing vessel contractility were determined to demonstrate functional changes. It was established that cooling the renal artery for only 30 minutes was enough to rule out the damage due to ischaemia-reperfusion. If clamping lasted for 45 minutes, venous cooling of the kidney in combination with antioxidant treatment was necessary to spare arterial function. Clamping for 60 minutes resulted in irreversible/permanent decrease in contractility even if hypothermia and antioxidant treatment were given simultaneously.

Animals↗

PubMed1997

Intraoperative monitoring of the motor pathway using transtracheal stimulation of the cervical spine in dogs.

Although SEP monitoring of the spinal cord has been a well established method recently, not an ultimate, perfectly developed technique for monitoring of the motor system is known so far, particularly, because of the disturbing effect of narcotic drugs and relaxants on the motor evoked potentials. In this study the upper part of the spinal cord was stimulated in 14 anesthetized and relaxed dogs with a cathode attached to the intratracheal tube and an anode fixed to the cervical spinous processes. Single and serial stimuli were applied. Recordings were obtained from the exposed right femoral nerve and quadriceps muscle. Averaging was necessary when using serial stimulations. Responses were consequent and reproducible during regular anesthesia. The origin of the different responses in the spinal cord is discussed. The method seems to be appropriate for intraoperative monitoring of the thoracolumbar spine.

Anesthesia, General↗

PubMed1997

Intrastromal corneal ring, a new refractive surgical technique to decrease myopia. Experimental and clinical results.

From among the wide range of keratorefractive operations, the authors applied the intrastromal corneal ring (ICR) technique to treat myopia. The results of operations performed on dogs' eyes were evaluated using slit lamp investigations, cornea topography and histological investigations. In the possession of favourable results, this kind of operation was successfully performed on three patients suffering from expressed unilateral myopia, too. The desired optical results (10.0 dioptres) proved to be permanent 3-10 months after surgery and were demonstrated by the patients' visual acuity as well as cornea topographic examinations. The surrounding of the PMMA ring situated intrastromally and the substance of the cornea remained calm and clear, respectively. The authors think that the ICR technique can successfully be applied in the treatment of myopia similarly to refractive surgical interventions such as radial keratotomy (RK) and excimer laser photorefractive keratectomy (PRK), which are widely used methods these days.

Animals↗

PubMed1997

Investigation of microcirculatory changes in the duodenum of dogs caused by surgical suture materials.

Surgical suture materials play an important role in the safe performance of surgical interventions. In our experiments we made an attempt to investigate what microcirculatory changes result from pulling the thread through the wall of the duodenum in Lembert stitches by including 3 kinds of absorbable and non-absorbable suture materials each (Catgut, Dexon, PDS, Silk, Ethibond, Ethilon). Research is still in the pre-experimental stage. In the long run, we hope to enrich the description of these suture materials by some new details. It could help prevent suture insufficiency, facilitate wound healing and thus, improved surgical safety.

Absorption↗

PubMed1997

Continuous pO2 and pCO2 measurement in brain tissue and cerebrovenous blood during different inspired oxygen settings. A porcine model.

The clinical use of brain tissue oxygen measurement in patients with severe head injury is increasing. It is important to compare the findings in brain tissue with jugular bulb oximetry, to obtain normal values and to find out limitations of the method. We evaluated a newly available multisensor probe simultaneously in the brain tissue and in the sagittal sinus in a porcine animal model. We placed the Paratrend 7-probe (BSL, High Wycombe, UK) in the left frontoparietal white matter and measured pO2 (ptiO2), pCO2 (pti CO2), pH and temperature while simultaneously measuring these parameters (pcvO2, pcvCO2) in the sagittal sinus in 7 pigs under general anaesthesia during a 100% oxygen enhancement. The relation between oxygen increase in brain tissue and in the sagittal sinus showed a coefficient of correlation (CCmean) r(mean) = 0.96. The quantitative response in brain tissue was much more sensitive than in the sinus. A close correlation between pCO2 in brain tissue and sagittal sinus and the increase of the inspired oxygen was seen: CC ptiCO2 to arterial oxygen pressure (paO2) - r(mean) = 0.67, CC pcvCO2 to paO2 - r(mean) = 0.88. This is important for interpreting measured values and introducing new coefficients for patient monitoring. Newly available continuous brain oxygen measurement methods will allow better understanding of brain metabolism in the future.

Algorithms↗

PubMed1997

Free radical reactions in the gallbladder.

The changes in the composition of bile can lead to the process of it's crystallization in the gallbladder. In bile model it was shown that inflammation with the generation of reactive oxygen metabolites may induce and influence the cholesterol monohydrate crystal formation within supersaturated bile. The aim of this study was to investigate the ability to detect traces of reactive oxygen metabolites, thiobarbituric acid reactive compounds and dien, in order to compare cholesterol and bilirubin contents in bile and serum during different conditions of inflammation in the gallbladder's wall. In every bile sample a reference to free radical reaction was found. There was an increase in MDA during higher degree of inflammation in the gallbladder, but no alteration in the dien content was observed. In case of common bile duct stones the bilirubin in the serum and in the gallbladder was parallelly high, but in other cases there were no significant correlation. In an occluded gallbladder with hydrops the content of protein was significantly higher in 85% of the cholesterol stones. As a conclusion, free radical reactions in the wall of gallbladder as well as in bile can induce gallstone formation. Further studies are needed to clarify the time which is sufficient to change the composition of bile and the degree of inflammation which lead to the onset of stone formation.

Bile↗

PubMed1997

Splenic autotransplantation after abdominal trauma in childhood. Clinical and experimental data.

Splenectomy is known to increase the risk of overwhelming bacterial infection. There is a decrease in immunoglobulin IgM and T-lymphocytes, primary antibody response to antigen challenge is impaired, altered opsonic function an Tuftsin deficiency are noted. Splenic autotransplantation has been suggested as a method of preserving function and this concept is supported by experiments in animals. Prior to operation on humans the technique was thoroughly elaborated and practised in animal experiments (dogs). After splenectomy, 6-8 thin segments (Furka's "spleen chip") are placed in between the plates of the major omentum. Within the period of ten years out of 52 patients 11 children (4 girls, 7 boys) suffered from abdominal trauma underwent total splenectomy, and than autotransplantation in the Kenézy Hospital in Debrecen, Hungary. In several patients the postoperative follow-up radionuclide imaging, IgM, and Tuftsin levels, and the haematological changes (leukocytes, differential blood count, platelet count, iron level in serum) unambiguously confirmed the function of the splenic tissue.

Abdominal Injuries↗

PubMed1997

Efficacy of prevention of thromboembolic complications with LMW-heparin in experiment.

The authors used an antithrombotic agent (Nadroparin Calcium) with anti-Xa effect in their experiments to prevent thromboembolic complications in the model of endoprosthetic replacement of the hip joint in mongrel dogs. 10 experimental animals (Group I.) were given doses of 100 A Xa ICU/kg/bwt of Nadroparin Calcium subcutaneously 4 hours prior to the operation and also once a day until the 3rd postoperative day; between the 4th and 10th postoperative days doses of 150 A Xa ICU/kg/bwt Nadroparin Calcium were given. The 10 control animals (Group II.) did not receive anticoagulant treatment. In both groups platelet count, activated partial thromboplastin times (APTT), prothrombin and fibrinogen levels as well as activated factor X inhibition (F Xa) were measured prior to surgery and also until the 14th postoperative day. No changes in APTT and prothrombin levels were detected during the experiment, however platelet count and fibrinogen levels as well as the extent of F Xa inhibition showed significant and different changes in groups I. and II. The Group I. which had received thromboembolic prophylaxis did not develop deep venous thrombosis or pulmonary embolism, but the control group did. Based on their investigations, the authors concluded that they had been able to achieve F Xa inhibition by giving the above mentioned doses of Nadroparin Calcium which was enough to prevent thromboembolic complications in their model experiment of implanting hip endoprosthesis.

Animals↗

PubMed1996

Laparoscopic implantation of temporary electrodes for bladder stimulation in dogs.

Five female mongrel dogs were used in an acute animal experiment. Under general anesthesia two monopolar wire electrodes armed with needles on either side were implanted into the bladder wall, the leads of both electrodes were then pulled through the abdominal wall. Filling of the bladder and intravesical pressure measurement were achieved through a suprapublic percutaneous cystostomy. Electrostimulation was carried out using the XEJ-2 experimental electroejaculator (biphasic pulses, pulse width 2.5 msec, approximately 70 mAmp, 50 Hz). The pressure changes within the bladder following electrostimulation were recorded, the effect of stimulation was observed endoscopically. Electrostimulation of the bladder wall resulted in micturition in all cases, showing an initial pressure peak at the commencement of electrostimulation followed by a decrease after onset of evacuation. We believe that laparoscopic implantation of temporary wire electrodes followed by percutaneous electrostimulation may open up new possibilities for bladder rehabilitation as well as for diagnostic investigations into the contractile capabilities of the bladder.

Animals↗

PubMed1996

Effect of glucagon and somatostatin on pancreatic secretion in dogs.

The authors investigated the effects of glucagon and a somatostatin preparation (Stilamin) on the secretion volume and on the secreted and absorbed enzyme levels of the pancreas. Four groups of dogs with an artificial pancreatic fistula were given a single intravenous injection of glucagon (group I, n = 8), intravenous drip-infusion of glucagon (group II, n = 8), intravenous drip-infusion of somatostatin (group III, n = 10) and intravenous drip-infusion of the carrier fluid, physiological sodium-chloride (control, group IV, n = 5), respectively. Pancreatic juices were collected and volume, pH, bicarbonate, amilase, lipase, trypsin and protein contents were determined. Serum amilase and lipase levels before and at the termination of the experiment were also measured. Intravenous drip-infusion of both Glucagon and Stilamin decreased pancreatic secretion, Stilamin being more effective than Glucagon. On the other hand, a single i.v. injection of Glucagon resulted in an increased secretion. The authors suggest that based on the observed inhibitory effect on pancreatic secretion, both glucagon and somatostatin could be used to reduce postoperative complications of pancreatic operations in the clinical practice.

Amylases↗

PubMed1993

[Autologous spleen transplantation].

Splenectomy is known to increase the risk of overwhelming bacterial infection. There is a decrease in immunoglobulin IgM, T-lymphocytes, impaired primary antibody response to antigen challenge, an altered opsonic function and a tuftsin deficiency. Splenic autotransplantation has been suggested as a method of preserving function and this concept is supported by experiments in animals (dogs). The study describes autotransplantation of the traumatized spleen in human beings for the preservation of splenic function. Eleven patients operated on for abdominal trauma in the Kenézy Hospital in Debrecen, required total splenectomy, than splenic autotransplantation. In these patients splenic slides were implanted in between two layers of omental pouch (Furka's "spleen chip"). In 10 patients the follow-up radionuclid imaging, the IgM level, and the tuftsin level unambiguously confirmed the functioning of the splenic tissue.

Abdominal Injuries↗