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Biomedical subjects

G Halmágyi

Publications and source records attributed to G Halmágyi.

15 recordsLinked to original sources
PubMed1980

Experimental study of marginal wedge resection and its practical application in the surgical therapy of staghorn calculi.

A surgical procedure for staghorn calculi, which are inaccessible to conservative therapy, is described. It not only provides for complete elimination of the calculus but may also contribute to the prevention of recurrences. The technique of marginal wedge excision of the renal parenchyma, developed in animal studies, is described in detail and 11 surgical cases are reported. Removal of staghorn calculi was successful all throughout, and renal function remained unaffected by the intervention in all of the cases. Recurrences were confined to a single case. The procedure is safe, it involves no greater surgical strain than does marginal nephrotomy, but its short-term metaphylactic results seem more promising. Assessment of the long-term results awaits further observations.

Adult↗
PubMed1980

Pancreatic tissue pH in experimental acidosis and alkalosis.

The pH was studied in pancreatic tissue and arterial blood in 22 dogs. Respiratory acidosis was induced by CO2 inhalations in 5 dogs, respiratory alkalosis by hyperventilation in 5 dogs, metabolic acidosis by intravenous(i.v.) infusion of 0.1 N HCl in 5 dogs, metabolic alkalosis by i.v. infusion of 4.2% Na bicarbonate in 5 dogs. The differences between the shifts of blood pH and tissue pH were not significant statistically. Infusion of Ringer's solution failed to affect the pH in blood and pancreatic tissue in two control animals. It is concluded, that with an adequate tissue blood flow the pancreatic tissue pH is uninformative unless the blood pH is known.

Acidosis↗
PubMed1980

Structural changes in the heart due to mechanical perfusion.

Acute myocardial damage such as epicardial, intramural and subendocardial haemorrhages and oedema are known to occur after mechanical perfusion. The results of animal experiments showed that local circulatory disturbances (hypoperfusion, hypoxia) due to mechanical damage of the blood (erythrocyte aggregation, denaturation) and or lasting hypoperfusion (microcirculatory hypoxia) are responsible for the acute lesions. In addition, the results offer a morphological explanation for the postperfusion heart failure.

Animals↗
PubMed1979

Consequences of experimental mitral insufficiency induced by chordotomy.

In mitral insufficiency induced by chordotomy in dogs beside the common diagnostic data the values for tissue perfusion indicative of myocardial microcirculation have been studied. Unexpectedly, a decrease of subendocardial circulation was found; this reduced circulation manifested itself with alterations such as changes in mitochondrial structure, increased quantity of subsarcolemic sarcoplasma, and degenerative symptoms.

Animals↗
PubMed1978

The donor kidney: I. Morphology of adequate preservation.

The structure of the dog kidney can be preserved in hypothermic intracellular-type solutions, but after 6 hours the appearance of pathologic focal changes such as mild oedema, lesions of the cellular elements, podocyte heteromorphism, vacuolization, disintegration of the basal membrane and of the cytomembrane structrues and even cell degeneration, is unavoidable.

Alkaline Phosphatase↗
PubMed1978

The donor kidney: III. Angio-architecture and function of the reimplanted kidney.

In the autogenous kidney preserved under conditions of hypothermia the development of a partial no-reflow phenomenon is unavoidable after reimplantation. The phenomenon is ascribed to ischaemic lesions induced by preservation. The consequences are functional disorders in the acute period (temporarily pathologic angiogram, nephrogram and proteinuria) and scars due to chronic focal necrosis. These unavoidable changes of the current preservation procedures are mostly of subclinical importance.

Animals↗
PubMed1978

Electrometric measurement of canine pancreatic tissue pH under conditions of preserved circulation and of ischaemia.

Canine pancreatic pH was measured by an electrometric method, which is described in detail. 60 measurements carried out in neuroleptanalgesia of the animals gave a mean figure of 7.29 +/- 0.10 for pancreatic pH in situ. For arterial blood pH in the same animals the mean value was 7.22 +/- 0.08. The difference between pancreatic and arterial blood pH is significant. Anaesthesia of 3 hr duration produced no significant change either in pancreatic pH or in arterial blood pH or in the serum amylase and serum lipase levels. Vascular isolation of the pancreas and adjoining duodenal segment was produced in 13 animals. In 10 of these ischaemia induced by clamping of the arterial pathways for 1 hr resulted in a fall of pH by 0.65 +/- 0.21. Restoration of blood-flow at the end of the first hour was followed by a return of pH to the original values. The 3 control animals revealed no significant changes in the pH and enzyme values.

Amylases↗
PubMed1978

Study of pancreatic tissue pH in the early stage of experimental acute pancreatitis.

Pancreatic pH was measured electrometrically over a period of 3 h in 34 dogs with acute necrotic pancreatis. The disease had been induced with sunflower oil in 10, with Na-taurocholate in 10 and with hen's egg yolk in 10 animals. Four dogs served as controls. The pH of the pancreatic tissue changed differently in the different groups, in accordance with the different pathomechanisms. Injection of sunflower oil was followed by a protracted acidosis of pancreatic tissue, that of taurocholate by a transitory moderate decline of pH. Egg-yolk produced an evanescent, slight fall in pancreatic pH, followed by complete normalization within a few minutes. The differences between the initial and the 3-h values attain the level of significance only in case of sunflower-oil pancreatitis.

Acute Disease↗
PubMed1978

pH-map of the stomach of normal and vagotomized dogs.

By means of electrometric surface measurements a peculiar pH-map of the mucosa of normal and vagotomized dog stomachs was obtained illustrating the different acid producing capacities of the various regions of the stomach, on the one hand, and showing that all types of vagotomy will reduce local acid secretion.

Acetylcholine↗
PubMed1977

Electric activity and oxygen tension of the brain during ischaemic anoxia and reperfusion.

Electric activity of the cerebral cortex and the mesencephalon and pO2 of the brain surface were analysed in 47 dogs after serial periods of cerebral anoxia induced by clamping of the aorta for less than 3 minutes and subsequent reperfusion. After restoring the circulation, characteristic stages were observed in the normalization of cortical electric activity and pO2. Improvement in cortical oxygen utilization progressed parallel to the return of rapid activity, though normalization of the EEG preceded that of oxygen utilization. The relative duration of the stages determined from the pO2 curve and from the parameters of electric activity allowed conclusions concerning the injury of the brain tissue. It is assumed that [1] after ischaemic anoxia an excess perfusion develops in the brain; [2] during anoxia, autoregulation of the cerebral vascular system ceases simultaneously with the disintegration of the oxidative metabolic processes of the brain; [3] restitution of the cortex is indicated more reliably by its oxygen consumption rate than by the normalization of EEG activity.

Animals↗
PubMed1977

Structural changes in temporarily ischaemized and reperfused dog kidneys.

The functional and structural study of the ischaemic renal parenchyma has become a central problem from the aspects of kidney transplantation. Reliable data are needed to establish the tolerance of separate or simultaneous cold and warm ischaemia. The changes appearing after 1- and 2-hour ligation of the renal artery (warm ischaemia) followed by autogeneous reperfusion after 3 to 24 hours were analysed on dog kidneys by means of light and electron microscopy. After 1 hour ligation, the changes seem fully reversible as the structures (mitochondria, basal membranes, brush border) suffer no fundamental lesion in spite of a general oedema. In contrast, 2-hour ischaemia caused serious morphological lesions (breaking up of the mitochondrial cristae, decay of the brush border, cell desquamation, necrosis, extensive oedema) leading to no-reflow phenomenon and irreversibility.

Animals↗
PubMed1976

[Auto-perfused multi-organ preparations. III. Interpretation of histologic changes in perfused organs].

The functional instability of "multi-organ" preparations has been studied by morphological and histochemical assessment of 46 autoperfused heart-lung-kidney-liver-duodenopancreas preparations. The organs of the autoperfused preparations were damaged to different degrees, but the damage was always a function of perfusion time (1 to 3 hours). The liver suffered the most serious lesions (stagnation, oedema, hepatocytolysis, hydropic degeneration) but lesions such as interstitial haemorrhage and oedema though in a milder form appeared also in the kidney. The heart structure was comparatively well preserved.

Animals↗
PubMed1976

Viability of extracorporeally perfused dog livers.

The possibility of structural and functional preservation of the isolated liver has been studied in dog experiments. A sterile liver preparation left in situ was worked out, having practically no ischaemic period, except during perfusion. Nevertheless, well-defined lesions (perivascular and interstitial oedema, dissociated contraction of the smooth muscle elements of the veins, cellula accumulation in the sinusoids) appeared, accompanied by a gradual reduction (microcirculatory disorders, enzyme derailment) of the function of hepatocytes.

Animals↗
PubMed1975

Resorption of 125I-labeled fibrin bioplast from the dorsal muscle of rats.

Fibrin bioplast is an implant material made from plasticized fibrin. The resorption and route of elimenation of 125I-tagged bioplast plates implanted into the back muscle of rats have been studied in 18 experiments. Variation in radioactivity of the implant, appearance of the activity in the urine and fecal output, supplemented with information on the radioactivity of the implant site and that of isolated organs, reveal that the elimination of bioplast begins on the 12th day and proceeds at an even rate without pathological tissue reactions. By the 42nd day 10 to 12% of the original material is present. The elimination of the implant material is complete and occurs mainly with urine through the kidneys.

Animals↗