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Biomedical subjects

J Koncz

Publications and source records attributed to J Koncz.

At least 19 recordsLinked to original sources
PubMed2001

Study of soil-plant (potato and beetroot)-animal cycle of nutritive and hazardous minerals in a rabbit model.

Potato and beetroot were grown on soils previously treated with heavy metal salts. Each particular microelement had a high concentration in both potato and beetroot [cadmium (Cd) 3.7 and 55.4, lead (Pb) 8.1 and 3.0, and mercury (Hg) 5.8 and 6.8 mg/kg dry matter, respectively]. In a metabolic balance trial 16 New Zealand White rabbits were fed 50 grams of basal diet and potato or beetroot ad libitum. The apparent digestibility of major nutrients and the accumulation of the microelements in different organs were investigated. Both potato and beetroot samples of high Pb and Hg content had the significantly (p < 0.05) lowest digestibility of organic matter and nitrogen-free extract. The Cd ingested from both potato and beetroot accumulated in the kidneys and liver (2.85 and 1.48 as well as 0.459 and 0.265 mg/kg, respectively). All the microelements (Cd, Pb and Hg) accumulated in the testicles (0.196, 0.32 and 0.199 mg/kg, respectively), reducing the rate of spermatogenesis. The tissue retention of heavy metals depends not only on the element itself, but also upon the 'carrier' feedstuff.

Animals↗
PubMed1996

Complex study of the physiological role of cadmium. IV. Effects of prolonged dietary exposure of broiler chickens to cadmium.

A 274-day long cadmium (Cd) feeding trial was carried out with broiler cockerel chickens. The diet of the control group (Cd-0, n = 6) contained no added Cd, whereas to the diet of group Cd-25 and group Cd-75 (n = 10 each) 25 ppm and 75 ppm Cd was added, respectively, in the form of CdSO4. The chickens were subjected to examinations described in detail earlier (Bokori et al., 1995b). In addition, the relative mass of five different organs (heart, liver, testis, spleen and brain), expressed as % of the body mass, was also determined. The clinical, gross and histopathological examinations and the assay of organs for mineral element content led to the following main findings. The feeding of diets containing 25 or 75 ppm Cd for more than 9 months did not cause signs indicative of acute Cd toxicosis or mortality in either group. The body mass gain of group Cd-75 chickens markedly decreased. Prolonged Cd exposure of the cockerels increased the relative mass of the liver and heart and markedly decreased that of the testes. The change in mass was proportional to the Cd load. The Cd-fed chickens developed focal pathological fatty infiltration of the liver, histiocytic infiltration of the jejunal mucosa and focal lympho-histiocytic interstitial infiltration and fibrosis of the kidney, which supports the view that prolonged Cd exposure leads to the development of subacute-chronic tissue changes in the kidney. The Cd content of the organs increased by one to three orders of magnitude, in direct proportion to the Cd load. The Cd content of most organs was 2 to 3 times as high as the value reported for broilers exposed to a similar Cd load lasting for 68 days (Bokori et al., 1995b). This indicates that the degree of Cd accumulation is markedly influenced by the duration of the Cd exposure. The highest Cd content was demonstrated in the kidney (724 mg/kg of dry matter). The Cd exposure markedly lowered the Zn, Mo and B content of the bones and the Ni content of the myocardium.

Animals↗
PubMed1995

Complex study of the physiological role of cadmium. III. Cadmium loading trials on broiler chickens.

Cadmium (Cd) loading trials were conducted on a total of 110 (3 x 10 and 4 x 20) broiler chickens prereared for 21 days. The control chickens received no cadmium, while chickens in the six treatment groups were given different doses of Cd as an aqueous solution of CdSO4 administered either into the crop or mixed in the feed. The chickens were kept in a climatized animal house and treated usually for 3-5 weeks (maximum 68 days), with the exception of group Cd-75 chickens which were treated up to 239 days of age. The chickens' health status, body mass and feed consumption were monitored throughout the trial. On days 14-20 and on day 42 of the trial 2 chickens per group, then at the end of trial a total of 25 chickens were killed in anaesthesia. These birds, together with chickens that died or were killed during the trial, were subjected to detailed gross pathological examination. From 11 organs (kidney, liver, spleen, testicle, brain, myocardium, skeletal muscle, lungs, digestive tract, pancreas, tubular bones) of these chickens samples were taken for assay for a total of 16 elements, as well as for light and electron microscopic examination. With the exception of groups Cd-30 and Cd-600, no abnormal clinical signs were observed in the first two weeks of the trial. Chickens of group Cd-30 died before day 8-12 of the trial among signs of complete anorexia, rapid emaciation, huddling and diarrhoea, while chickens of group Cd-600 died before day 28, showing similar clinical signs. The body mass of chickens fed a Cd-supplemented diet either remained constant or decreased substantially, in a degree proportional to the Cd load. The only exception was group Cd-2.5, in which the average body mass of birds at the end of week 8 slightly exceeded that of the controls. Four out of the 10 cockerel chicks fed a diet containing 75 ppm Cd up to 239 days of age died of intercurrent diseases; the remaining six grew well and reached a body mass of 3.8-4.3 kg. Feed conversion efficiency was satisfactory in the control group and in group Cd-2.5 (2.1 and 2.4 kg, respectively) and could not be evaluated in a realistic manner in the other groups. At necropsy, the cockerel chicks of groups Cd-30 and Cd-600 showed severe emaciation, liver and kidney degeneration, myocardial hypertrophy and cardiac dilatation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1986

Haemodynamic and echocardiographic findings after aortoventriculoplasty.

Aortoventriculoplasty (AVP) is an established operative procedure for the enlargement of different types of severe left ventricular outflow tract obstruction. Between 1974 and 1985 75 aortoventriculoplasties were carried out in 72 patients ranging from 5 to 34 years of age. Three patients had to be reoperated upon due to significant right ventricular outflow tract obstruction, outgrown prosthesis, and dissecting aortic aneurysm. There were 7 early deaths (mortality rate 9.3%) and one late death (1.3%) following AVP. Out of the last 55 patients only 2 died (3.6%). In contrast to the unsatisfactory haemodynamic results of previous conventional operations. AVP reduced the mean residual gradient at rest across the left ventricular outflow tract from 84 +/- 23 mmHg (range 50-160 mmHg) to 12 +/- 12 mmHg (range 0-65 mmHg). Except in 2 patients, no gradient increased more than 15 mmHg with isoproterenol. In the cross-sectional echocardiogram, the left ventricular outflow tract was enlarged from 1.9 +/- 0.42 to 3.1 +/- 0.39 cm after AVP, whereas the aortic annulus had been expanded from 2.4 +/- 0.36 to 3.2 +/- 0.35 cm (n = 17). The mean length of the inner patch covering the septal incision measured 2.1 cm +/- 0.4 cm (n = 37). Our recatheterization studies after AVP revealed equally good haemodynamic results in all types of left ventricular outflow tract obstruction which cannot be relieved by conventional surgery.

Adolescent↗
PubMed1981

[The "steal" syndrome and the development of pulmonary arterio-venous shunt after Glenn and/or Fontan operations (author's transl)].

18 patients with superior vena cava-right pulmonary artery (Glenn) anastomosis and 7 patients with right atrium-pulmonary artery (Fontan) conduit operation were investigated by selective angiography, oximetry and contrast echocardiography. 11 patients with Glenn anastomosis (61.1%) developed a "steal" syndrome in 4 11/12 to 9 7/12 years postoperatively. In 2 patients pulmonary arteriovenous shunt could be documented by selective angiocardiogram, oximetry and contrast echocardiography, and in 1 patient by contrast echocardiography only (16.6%). None of the patients with Fontan operation developed detectable pulmonary arteriovenous shunt in the follow-up period. The effect of the changed haemodynamics after Fontan operation on the "steal" syndrome in patients with prior performed Glen anastomosis is that to diminish or abolish collateral flow. There is no influence on the abnormal intrapulmonary arteriovenous communications.

Adolescent↗
PubMed1981

[Hypertensive pulmonary vascular disease in complete transposition of the great arteries (author's transl)].

Pulmonary vascular disease and heart failure are the two major problems in complete transposition of the great arteries (TGA) with increased pulmonary flow. Hypertensive pulmonary vascular disease was observed in patients with complete TGA and increased flow (3.6%) as well as in those without increased pulmonary flow (3.3%). An intact ventricular septum or pulmonic stenosis did not appear to prevent the occurrence of progressive pulmonary vascular disease in all patients. The pulmonary lesion observed in these subjects cannot be explained by chronic severe volume overload alone. Clinically unrecognized pulmonary microthrombi are an additional cause for the development of pulmonary vascular disease in patients with complete TGA. Therefore cyanosis and its complications can be a major factor beside increased pulmonary flow in causing pulmonary vascular changes. Early corrective surgery performed after the age of 3 months is the therapy of choice to avoid progressive pulmonary vascular damage and other thrombo-embolic accidents.

Cardiac Catheterization↗
PubMed1980

Fontan procedure and surgical modification in tricuspid atresia.

Nineteen patients with tricuspid atresia and reduced lung perfusion (valvular-and/or subvalvular pulmonary stenosis, transposition of the great arteries and/or single atrium) were operated in the period 1975--1979. The surgical procedures employed varied according to the additional cardiac defects. The age of the patients was between 2 and 18 years. Eleven children received a contuit with a Hancock valve, 8 children a valveless conduit. In 9 patients it was possible to connect the conduit to the right ventricle using the pumping action of the right ventricle with an anatomically intact pulmonary valve. Six patients died (4 early deaths, 2 late deaths, early mortality rate 21%). In this study, the postoperative courses, which were complicated in several cases, are related to the hemodynamical findings. Thirteen children were examined between 1 and 38 months following the operation. Cardiac catheterization was performed in 10 patients. Of the 13, 10 had fully saturated arterial blood. A remnant atrial defect was demonstrated in one child, and 2 displayed intrapulmonary shunts attendant to Glenn anastomoses which had been in place for 10 to 12 years. Among the patients the right atrial pressure ranged from 10 to 20 mmHg with a mean value of 14.5 +/- 0.9 mmHg. An increase in size of the right ventricle was demonstrated angiographically in the case of 2 patients who had valve-bearing conduits to the right ventricle.

Adolescent↗
PubMed1980

[Reconstruction of underdeveloped right ventricle and tricuspid hypoplasia (author's transl)].

Total correction of underdeveloped right ventricle related to tricuspid hypoplasia has been performed in 6 patients at the department of thoracic and cardiovascular surgery University Göttingen. In 5 patients reconstruction of a four-chamber-four-valved heart could be accomplished. 1 patient with a poor result after Fontan's operation, performed one year previously, showed a significant growth in size of the hypoplastic right ventricle in the postoperative angiogram, but died 14 hours after reoperation. Prior to corrective surgery, 4 patients required 1 or 2 palliative procedures: 3 Glenn- and 2 Blalock-Taussig operations and a pulmonary valvulotomy in 1 patient. A Hancock-valved conduit was inserted between the right atrium and the hypoplastic right ventricle as an inlet of this chamber after closure of the ASD and VSD in 4 patients. The conduits are bypassing the hypoplastic tricuspid valve orifices closed during corrective surgery. In the remainder 2 patients with moderate tricuspid and right ventricle hypoplasia, closure of the ASD was performed only. Anomalous muscle bundles and fibrous tissue inside the right ventricular cavity were resected surgically, safely. 4 to 12 months after corrective surgery the 5 survivors were investigated by cardiac catheterization. In the 3 patients operated with a valved conduit there was a moderate growth in size of the hypoplastic right ventricle, the right atrial pressure was elevated and ranged from p = 14 to 16 mm Hg. There was a slight right atrial-right ventricular gradient of 4 mm Hg across the valved conduit. The 2 patients with closure of the ASD and VSD only had a nearly normal-sized right ventricle and a right atrial pressure of p = 10 mm Hg or less at the postoperative right ventricle and a right atrial pressure of p = 10 mm Hg or less at the postoperative investigation. All of them were acyanotic and had an improved or normal exercise tolerance. We concluded that reconstruction of an underdeveloped right ventricle in well-selected cases will yield more physiological benefits than do current surgical procedures, in which a conduit is interposed between the right atrium and the main pulmonary artery.

Adolescent↗
PubMed1979

Aortoventriculoplasty for tunnel subaortic stenosis and other obstructions of the left ventricular outflow tract. Clinical and hemodynamic results.

A new therapeutic concept of enlarging the outflow tracts of both ventricles with a patch and inserting an aortic prosthesis has been developed for the treatment of tunnel subaortic stenosis. This operation has been applied clinically since June 1974 on several types of obstruction in the outflow tract of the left ventricle. Twenty-one operations have been performed on 20 patients under the age of 18 years, with an overall mortality of 24% and no late deaths. Seven patients developed complete right bundle branch block or left anterior hemiblock or both as a result of this operation; transient atrioventricular block and complete left bundle branch block occurred in one patient each. In no case, however, did rhythm disturbances contribute to death. In one patient, the septal incision injured a septal coronary artery, with fatal result. Fourteen patients had catheterization studies postoperatively. Although previous conventional surgery had been unsuccessful, aortoventriculoplasty (AoVPI) reduced the mean gradient across the left ventricular outflow tract significantly (p less than or equal to 0.01), from 94.7 +/- 25.5 mm Hg to 14.4 +/- 17.2 mm Hg, leaving the end-diastolic pressure practically unchanged. No significant defect remained in the patch-covered septal incision. Thus, we consider AoVPI to be the operation of choice for tunnel subaortic stenosis, for valvular aortic stenosis with a narrow annulus and in cases where an artificial aortic valve has become too small because of the patient's growth.

Adolescent↗
PubMed1978

[Corrected transposition of the great arteries: surgical treatment of associated cardiac defects (author's transl)].

Corrected transposition of the great arteries is often associated with other cardiac anomalies. We report our experience with the correction of the associated cardiac defects in 13 cases: ventricular septal defect with pulmonary hypertension (5 cases), ventricular septal defect with obstruction of pulmonary outflow tract (5 cases), obstruction of pulmonary outflow tract (2 cases), ostium primum defect (1 case). The possible surgical approaches for repair of the cardiac anomalies are described and the results of the operative correction are communicated. Precise diagnosis, the knowledge of the unusual disposition of the conducting tissues and new surgical approaches are prerequisite for successful correction.

Adult↗
PubMed1978

[Hemodynamic results of surgery for congenital supravalvular aortic stenoses (author's transl)].

Supravalvular aortic stenosis is either a syndrome combined with typical face characteristics mental retardation and peripheral pulmonary artery stenosis or it occurs as an isolated congenital heart defect. The diagnosis was confirmed in 137 patients by means of catheterization and angiocardiography; 35 pediatric and 10 adult patients were considered to be candidates for corrective surgery because of the severity of their disease. Age varied from 3 to 32 years. 7 patients (15,5%) died. Recatheterization was performed in 12 children 5,6 +/- 4,1 years after surgery. Left ventricular pressures were decreased from 184,1 +/- 28,4 to 155,5 +/- 32,1 mm Hg, and the pressure gradients between left ventricle and the aorta fell from 101,2 +/- 19,7 to 29,1 +/- 23,1 mm Hg. The postoperative values varied between 0 and 80 mm Hg. Operative results are discussed in relation to the anatomical type malformation and the operative technique.

Adolescent↗
PubMed1978

Results of aortoventriculoplasty in 21 consecutive patients with left ventricular outflow tract obstruction.

Results of aortoventriculoplasty (AVP) are reported in 21 patients with various types of left ventricular outflow tract obstruction (LVOTO). The concept of AVP is based on creating a surgical aortoseptal defect which is patched to provide the largest possible outflow tract to the left ventricle. Lesions consisted of isolated diffuse fibromuscular subaortic stenosis in six patients, diffuse subaortic stenosis and associated other cardiovascular anomalies in five, hypoplastic aortic anulus in two, idiopathic hypertrophic subaortic stenosis (IHSS) in two, and stenosis of a previously implanted aortic valvular prosthesis in three patients. Ten patients had had at least one unsuccessful previous surgical attempt to relieve the LVOTO. The coexisting mitral incompetence in IHSS disappeared after AVP alone. Immediate postoperative hemodynamic results were excellent in all cases. Postoperative death in five patients was due to advance myocardial failure in two, brain damage in one, transection of a dominant septal artery in one, and severe acidosis with renal failure in the last case. However, in the last 16 patients (17 operations) the only death (5.8 percent) was that caused by uncontrollable acidosis. Follow-up results indicate that 16 patients are clinically doing well, and hemodynamic studies in 14 patients are rated as excellent or good from 1 to 25 months postoperatively. It is concluded that AVP is an effective operation for managing all types of LVOTO and can be used routinely with an acceptably low mortality rate.

Aorta↗
PubMed1977

[Supporting the pumpfunction of the right atrium. A new therapeutic concept after physiological repair of tricuspid atresia (author's transl)].

A new indication for the External Conterpulsation (ECP) is demonstrated. Due to the venous augmentation a "pulse wave" is created in the V. cava inferior and in the right atrium and the ECP acts as a "peripheral pumpventricle", thus increasing pulmonary blood flow and left ventricular enddiastolic pressure. This new application of ECP is of valve in cases with low output syndrome after physiological repair of tricuspid atresia as demonstreated in a case report.

Adolescent↗
PubMed1976

[The portacaval anastomosis (author's transl)].

All patients treated in the authors' clinic for portal hypertension from 1958 to 1975 are reviewed and the problems encountered with portacaval anastomoses are explained with special reference to encephalopathy and hepatic failure. Intrahepatic block was recorded in 88% of 722 patients. Portacaval anastomoses were constructed in 292 cases, splenorenal anastomoses in 175, and mesenterico-caval anastomoses in 12. Among the patients with stationary cirrhosis, the 6-year survival was unrelated to the type of operation performed and amounted to approximately 70%, while 6-year survival was only 40% in patients with progressive cirrhosis of the liver, whether they received surgical or conservative treatment.

Esophageal and Gastric Varices↗