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Biomedical subjects

I Mikó

Publications and source records attributed to I Mikó.

At least 37 records · Page 2Linked to original sources
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

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↗
PubMed1990

Experimental study of parenteral nutrition and of the exocrine function of the pancreas.

The effect of parenteral nutrition on the pancreatic secretion was studied under experimental conditions. Experiments were carried out in 24 mongrel dogs. In all animals pancreatic fistulas were created for collection of pancreatic juice. Subsequently, in three groups (6 dogs in each) parenteral nutrition via a catheter enterostomy was applied in three different segments of their small bowels, while collecting the pancreatic juice. Group IV served as control where no parenteral nutriment was administered. The amount, pH, protein and enzyme levels of the pancreatic juice secreted during 4 hours were studied in all groups. The experiments revealed that parenteral nutrition at the initial segment of the jejunum enhanced pancreatic secretion, while this was not experienced in the other groups. The effect is assumed to be humoral, rather with a secretin-like stimulation. Based on the experimental results, the authors call attention to the fact that, during treatment of acute pancreatitis, if a feeding enterostomy is constructed for calorie intake, it should not be performed within the first metre of the jejunum.

Animals↗
PubMed1990

Experience obtained during liver resections made under experimental conditions by a telescopic compressor (AKE).

Liver resection experiments in dogs made by the AKE telescope compressor are reviewed. It is established that the instrument can be applied to the liver parenchyma of varying size and compressibility. The time of resection is short and the intervention entails only minimal loss of blood. Using this solution, it is not necessary to produce the transitory warm ischaemia of the liver.

Animals↗
PubMed1990

Partial splenectomy performed by a special technique in dogs.

Closure of the splenic surface is solved at splenectomy by placing a raw of sutures using a double thread inserted at the same level by two straight needles. This technique does not require interpositions with a good haemostasis and so favours wound healing. It does not need many instruments and is easy to perform.

Animals↗
PubMed1987

Experimental study of autologous free omental grafts.

The fate of intraabdominal free omental grafts was studied in 15 dogs and it was found that a connection between the hollow organ and the transplanted omentum was established only when the former had been injured. The larger, pigeon-egg-sized free fatty omental grafts became necrotic already from the fourth day onwards being replaced by an abscess-like structure, while in thin membrane-like grafts tissue necrosis due to the creeping in of connective tissue was less marked. In both cases, an intact, omentum is creeping over the graft from the adjacent region, i.e. the ultimate covering is actually provided by the pedicle graft.

Animals↗
PubMed1986

Restoration of skin defects with fibrin glue.

After experiments with absorbable bioplasts for substitution of skin defects, this time the absorbable fibrin glue named Tissucol was used by the authors. The experiments on 22 dogs unanimously proved that, beneath the layer of tissue adhesive, scarring occurred free of inflammation as compared to the controls where inflammatory phenomena were not excluded. The procedure has been found good and useful in high-degree burns and injuries up to their final management.

Animals↗
PubMed1986

Data on renal hypothermia by the venous passage.

The temperature values obtained in renal hypothermia through the venous circulation were biometrically analysed. It was found that there could be even about 4 degrees C temperature differences between the lower and upper poles of the kidney, always as large as 4 degrees C could be elicited in the first five minutes of hypothermia, the lower pole being colder. Similar but smaller differences were observed in ten minutes' hypothermia.

Animals↗
PubMed1986

Partial experimental autotransplantation of the spleen.

The authors performed autotransplantation of the spleen in 45 dogs. They found that, the pieces of the transplanted spleen underwent necrosis, but new malphigian bodies formed on their surface. These latter took over the sepsis-inhibiting function of the spleen. Thus the grafting of spleen can be useful and worth doing. Spleen should be transplanted in thin slices since in case of a larger piece they may necrotize and give rise to abscesses.

Animals↗
PubMed1986

Combined use of bioplast and tissue adhesive in experimental nephrectomies in in situ renal hypothermia.

In transvenous regional hypothermia wedge-shaped and flat lower pole resections were made in dogs. The cut surface of the kidney was covered by the combination of tissue adhesive and bioplast without sutures. It was found that the polymerization time of the tissue adhesive almost doubled. The usual rigidity of the adhesive was more expressed than in normothermia and it was not influenced by re-heating. Recovery conditions were more favourable; a larger portion of the parenchyma could be preserved than with the traditional closure with needle and thread.

Animals↗