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Biomedical subjects

J Karner

Publications and source records attributed to J Karner.

At least 37 records · Page 2Linked to original sources
PubMed1992

Dacron versus polytetrafluoroethylene for Y-aortic bifurcation grafts: a six-year prospective, randomized trial.

BACKGROUND: A prospective, randomized trial was conducted to compare Dacron with expanded polytetrafluoroethylene (ePTFE) in reconstructive aortoiliac surgery. No comparable trial with a prospective, randomized design with a comparable number of patients or an equal long-term follow-up period can be found in the literature. METHODS: Between 1984 and 1989, 165 patients were randomized for either Dacron or ePTFE on the basis of age, sex, indication for surgery, diabetes, nicotine consumption, runoff, and operative approach. The two groups were well matched for randomization criteria, as well as the incidence of aneurysms. RESULTS: No statistically significant difference was found between the two graft materials in terms of patency rates (corrected 3-year patency rates: Dacron = 95% vs ePTFE = 95%; Breslow, p = 0.83; Mantel-Cox, p = 0.74). Subgroup analysis comparing long-term patency rates of the two graft materials and relating them to poor runoff, good runoff, aneurysms, and arterial occlusive disease also failed to show any significant differences between ePTFE and Dacron. Early graft failure (n = 6; 3.6% of the patient population; p = 0.045) and severe abdominal graft infection (n = 3; 1.8% of the total population) were seen only in ePTFE grafts. However, these did not affect the corrected long-term patency rate of ePTFE grafts. There were five late graft failures with PTFE (3.0%) and four with Dacron (2.4%). CONCLUSIONS: Graft materials currently available for aortoiliac repair were comparable in terms of corrected long-term patency rates. The alleged advantages of PTFE were not confirmed by our data. PTFE grafts were associated with a higher rate of complications, and more redo operations were required to duplicate the results obtained with Dacron.

Aorta↗
PubMed1991

Effect of alpha-ketoglutarate infusions on organ balances of glutamine and glutamate in anaesthetized dogs in the catabolic state.

1. The salt complex of L-(+)-ornithine and alpha-ketoglutarate (2-oxoglutarate) has recently been proposed for the treatment of patients in the catabolic state. As yet, it is unclear which of the two substrates (ornithine or alpha-ketoglutarate) is responsible for the anticatabolic effect. We infused alpha-ketoglutarate into anaesthetized post-operative dogs in order to investigate whether infusion of alpha-ketoglutarate affects the flux of glutamine and glutamate between skeletal muscle and the splanchnic bed. We used three infusion rates: 3, 10 and 20 mumol min-1 kg-1. A steady state of alpha-ketoglutarate concentration in arterial whole-blood was attained only when the infusion rate was 3 mumol min-1 kg-1. 2. Arterial whole-blood concentrations of alpha-ketoglutarate were 8.8 +/- 1.2 mumol/l in the basal period and rose to 208 +/- 41, 344 +/- 61 and 1418 +/- 315 mumol/l after 60 min infusions of alpha-ketoglutarate at 3, 10 and 20 mumol min-1 kg-1, respectively. 3. alpha-Ketoglutarate uptake was measured in skeletal muscle, liver, gut and kidneys in the basal period and during the infusion of alpha-ketoglutarate. The net uptake of infused alpha-ketoglutarate was highest in the skeletal muscle, followed by kidneys, liver and gut. 4. The alpha-ketoglutarate load increased the muscular tissue content of alpha-ketoglutarate from 49.5 +/- 5 to 142 +/- 15 nmol/g of dry substance (P less than 0.001), but did not alter the muscular glutamate or glutamine contents.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Alanyl-glutamine infusions to patients with acute pancreatitis.

In this study we infused different amounts of glutamyl-dipeptides (group 1: 1.5 g ALA-GLN + 3.5 g GLY-GLN, group 2: 20 g ALA-GLN, group 3: 40 g ALA-GLN) for a period of five days into patients with acute pancreatitis. In spite of this high amount of ALA-GLN administration we were not able to normalise the depleted glutamine pool of skeletal muscle in these catabolic patients.

Journal Article↗
PubMed1990

First report on the occurrence of human cases of alveolar echinococcosis in the northeast of Austria.

Since Posselt (1928) it is known, that Echinococcus multilocularis, the causative organism of alveolar echinococcosis, is prevalent in the western and southern provinces of Austria (Vorarlberg, The Tyrol, Salzburg, Carinthia, Styria). Recent distributional data confirmed the existence of these endemic areas in the mountain range of the Alps. Within the period from 1983 to 1988 human cases of obviously autochthonous alveolar echinococcosis were detected in the northeast of Austria, north of the river Danube, for the first time. This paper presents a clinical, diagnostic, therapeutical and epidemiological documentation of these three cases (2 females, 1 male), which represent the eastern most records of autochthonous E. multilocularis infections of the Central European distribution area of alveolar echinococcosis.

Austria↗
PubMed1989

Influence of alanylglutamine infusion on gastrointestinal glutamine and alanine metabolism in anesthetized dogs.

In this study we administered an infusion of alanylglutamine (10 mumol/kg.min) for 60 minutes to postoperative anaesthetized dogs with catheters placed in the portal and hepatic veins. Arterial plasma levels of alanylglutamine were 83 +/- 27 mumol/L 20 minutes after the onset of the infusion and remained constant throughout the infusion period. Plasma levels of glutamine and alanine approximately doubled compared with preinfusion levels, indicating a release of these amino acids from the dipeptide. The halflife of alanylglutamine, calculated after bolus injection of 2 g, was 1.7 +/- 0.5 minutes. Alanylglutamine was extracted from the liver and the gut (0.9 +/- 0.3 and 0.5 +/- 0.1 mumol/kg.min, respectively). In the basal period (without infusion of alanylglutamine), a glutamine uptake by the liver and the intestine was found. Alanine was taken up by the liver and released from the gut. The infusion of alanylglutamine significantly increased the hepatic uptake of glutamine and alanine (from 0.8 +/- 0.2 to 3.8 +/- 0.6 and from 3.0 +/- 0.4 to 7.5 +/- 0.7 mumol/kg.min respectively; P less than .01) and did not significantly change the intestinal uptake of glutamine and the release of alanine. We conclude that the infusion of alanylglutamine markedly influences the hepatic metabolism of glutamine and alanine, probably via the increased arterial and portal levels of glutamine and alanine.

Alanine↗
PubMed1989

Infusion of dipeptides as nutritional substrates for glutamine, tyrosine, and branched-chain amino acids in patients with acute pancreatitis.

In this study we investigated the effect of a total parenteral nutrition supplemented with synthetic dipeptides on plasma and muscle amino acid metabolism in four patients with acute pancreatitis. We infused an amino acid solution containing alanylglutamine, glycylglutamine, glycylvaline, glycylisoleucine, glylcylleucine, and glycyltyrosine for a period of five days in daily dosages of 10.3, 22.1, 68.8, 37.2, 42.5, and 15.7 mmol, respectively. The plasma levels remained below 100 mumol/L for all infused dipeptides. The plasma concentrations of alanylglutamine were not measurable. Mean peptide urine excretion remained below 5%, with the exception of glycylglutamine (8.5% +/- 5.1%). Arteriovenous concentration differences of the dipeptides across the leg were not significantly different from zero, indicating that the infused dipeptides have no important role in the nitrogen exchange of skeletal muscle. A marked intracellular glutamine deficiency in skeletal muscle was found in all four patients (5.1 +/- 0.6 mmol/L v 19.5 +/- 0.8 in healthy subjects) before infusion. Intracellular glutamine concentration was significantly higher after the infusion period (5.1 +/- 0.7 v 9.5 +/- 1.8 mmol/L, P greater than .05), but no normalization of the intracellular glutamine levels was achieved by the infusion of the two glutamine-containing peptides. We conclude that peptides are well metabolized as substrates for parenteral nutrition in catabolic patients. Furthermore, the infusion of glutamine peptides caused a significant increase in intracellular glutamine levels; however, the dosage of glutamine peptides was too low to normalize the muscular glutamine concentrations.

Acute Disease↗
PubMed1989

Groin infections following vascular surgery: obturator bypass (BYP) versus "biologic coverage" (TRP)--a comparative analysis.

Deep infections in the groin complicating vascular surgical procedures pose a serious problem, in the treatment of which two alternative methods are available: (1) Removal of the graft and the construction of an extra anatomic bypass (obturator canal bypass, BYP), or (2) retaining the graft and achieving healing of the infected wound by various biological materials, such as omentum or an inferior rectus abdominis muscle flap (TRP). The probability of patient and limb survival was estimated by the Kaplan-Meier method and possible differences between both groups checked using Breslow's and Mantel's tests. No statistically significant differences were found and a variety of factors with potential influence on the outcome were considered equally balanced. However, as soon as the catastrophic event of infection plus haemorrhage enforced emergency surgery, the incidence of success differed markedly: in the BYP group 6 infections healed out of 8 and in the TRP group 1 out of 6.

Adult↗
PubMed1989

Plasma glutamate--a prognostic marker of cancer and of other immunodeficiency syndromes?

Elevated plasma levels of glutamate (GLU) have been reported to occur in patients with malignancies and other immunodeficiency syndromes (IDS). To evaluate, whether GLU is useful as prognostic indicator, the plasma concentrations were determined in patients with colorectal carcinoma (CRC), with breast cancer (BRC), and with HIV-infection (HIV). The results were correlated with the disease-stages, and compared with data obtained from patients with benign diseases of the same organ, as well as from sex-matched healthy volunteers. GLU concentrations (volunteers: 27.4 +/- 17.6 mumol/l) were elevated in all BRC patients (range of mean values: 53.5-83.2 mumol/l), in CRC patients with T2-T4-tumours (means: 46.8-85.9), and in HIV+ patients of stage WR 5, 6 (means: 53.9-69.7 mumol/l). All CRC- and BRC-patients with metastases showed highly significant elevations of GLU concentrations (p less than 0.001), but there were no direct correlations between disease stages and GLU levels. Pre-operative patients with benign diseases (diverticulitis, adenoma = GID; and mastopathy = MTP) showed increased GLU levels, which were comparable to those of the tumour patients. The glutamine/GLU ratios (volunteers: 19.3 +/- 15.0) were decreased only in HIV-WR 6 (7.6 +/- 2.1), and BRC-stage 4 (8.0 +/- 1.7). From these results we deduce that the plasma GLU concentrations do not allow a discrimination either between patients with malignancies and without, and between persons of different disease stages.

Aged↗
PubMed1989

Current trends in the management of carcinoma of the pancreatic head.

Between 1965 and 1987, 783 patients were treated for ductal adenocarcinoma. Of these, 59% had carcinoma of the pancreatic head and 22% presented with carcinoma of the body or tail. In 19% of the cases the entire organ was involved. Two hundred and twenty-six patients (25.5%) underwent exploratory laparotomy; 420 patients (55%) had palliative operations, and 137 (18.5%) were resected for cure. In the past 3 years the resection rate increased from an original 18.5% to 28% (43 resective procedures in 153 patients). In 37 of the 137 patients (28%) surgery had to be extended to the portal vein, the superior mesenteric vein, the kidneys, adrenals, colon, stomach, liver and lymph nodes to ensure adequate radicality. At the same time in-hospital mortality (including deaths after extended procedures) dropped to 7%. Of the 137 patients resected for cure, 47% were alive at 1 year, 22% at 2 years, 12% at 3 years, 7% at 4 years, and 5% at 5 years. Mean survival time excluding in-hospital deaths was 18.65 months. In the first 15 months after surgery there was no difference in survival between standard resections and extended resections. Patients undergoing partial pancreaticoduodenectomy fared significantly better (p less than 0.01; Mantel) than those who had total resections, in terms of both median survival (10.8 versus 5.4 months) and mean survival (19.0 versus 7.82 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Intraductal, Noninfiltrating↗
PubMed1989

Glutamine-containing dipeptides as infusion substrates in the septic state.

Recently a relationship has been postulated between lowered intracellular glutamine concentrations in the skeletal muscle and the rate of protein synthesis. We investigated the effect of 48 hours of parenteral nutrition supplemented with a solution containing glutamine in free or dipeptide form (alanylglutamine or glycylglutamine) on the intracellular glutamine pool in skeletal muscle and on the hind limb exchange of glutamine in dogs with sepsis after surgery. Before surgery, dogs were fasted for 48 hours. We used glutamine dipeptides as sources because they remain stable in an aqueous solution. Nutrition solutions were isocaloric (17.8 kcal/kg body weight/day on day 1 and 35.6 kcal/kg on day 2) and isonitrogenous (0.33 gm nitrogen/kg body weight/day), providing 2.6 mmol/kg body weight/day as glutamine source. During starvation, muscular free glutamine levels decreased by 41% to 10.4 mmol/L (p less than 0.001). On the second postoperative day the dogs had lowered plasma protein levels, a sharp drop in platelet count, an increase in the leukocyte count, and positive blood cultures. None of the solutions investigated in this study was effective in repleting the glutamine pool during 2 days of postoperative nutrition (11 +/- 2.0 mmol/L without glutamine, 10.3 +/- 2.2 mmol/L with glutamine plus alanine, 9.9 +/- 1.6 mmol/L with alanylglutamine, 7.5 +/- 1.1 mmol/L with glutamine plus glycine, and 7.2 +/- 1.2 mmol/L with glycylglutamine, respectively). The release of glutamine from the hindquarter was 631 +/- 38 nmol/kg body weight/min in the control group and decreased significantly in dogs receiving alanylglutamine (13.5 +/- 45 nmol/kg body weight/min; p less than 0.001) or the constituent amino acids (265 +/- 66 nmol/kg body weight/min; p less than 0.01) but was unchanged in dogs receiving glycylglutamine or glutamine plus glycine. We conclude that the duration and dosage of glutamine administration (equivalent to 26 gm glutamine per day in a patient weighing 70 kg) used in this study are not sufficient to restore glutamine deficiency of the skeletal muscle in the depleted state.

Alanine↗
PubMed1988

Alanylglutamine reduces muscle loss of alanine and glutamine in post-operative anaesthetized dogs.

1. The present study examined the effect of an infusion of the dipeptide alanylglutamine or of the corresponding amino acids alanine and glutamine in equimolar amounts (10 mumol min-1 kg-1) on the canine hindlimb exchange of alanine and glutamine in the post-operative anaesthetized dog. In contrast to glutamine, the dipeptide alanylglutamine is stable in aqueous solution and therefore would be a suitable substrate for parenteral nutrition. 2. The infusion of alanylglutamine increased (a) the arterial concentration of alanylglutamine to a plateau level (120 +/- 9.5 mumol/l, mean +/- SEM) 20 min after start of the infusion, (b) the mean arterial alanine concentration from 761 +/- 42 to a plateau of 1500-1700 mumol/l (P greater than 0.01) and (c) the arterial glutamine concentration from 407 +/- 51 to a plateau of 1050-1500 mumol/l (P greater than 0.01). Alanine and glutamine levels were slightly higher (14% and 26%, respectively, NS) in the group receiving the equimolar amount of alanine and glutamine. 3. Infusion of alanylglutamine for 1 h abolished the net efflux of glutamine (from -0.80 +/- 0.1 to -0.03 +/- 0.2 mumol min-1 kg-1; P greater than 0.05) and invoked a net influx of alanine (from -0.50 +/- 0.19 to +0.27 +/- 0.14 mumol min-1 kg-1; P greater than 0.01). These changes were similar to those achieved when the two amino acids were infused. 4. This study demonstrates that during short-term administration of alanylglutamine or of the corresponding amino acids the nitrogen release from the hindlimb of the anaesthetized post-operative dog via alanine and glutamine is reduced.

Alanine↗
PubMed1988

Influence of leupeptin on protein and amino-acid metabolism in septic rats.

We investigated the influence of leupeptin (LP) intraperitoneal injection (40 mumol/2 days) on protein and amino-acid metabolism of septic rats (cecal ligation). All septic rats lost weight (-17 +/- 4 g), which was not prevented by LP administration (-24 +/- 1.8 g, n.s.). LP injection evoked weight loss even in normal rats (p less than 0.05 vs controls). Weight loss was accompanied by enhanced urinary nitrogen losses in all three groups. LP reduced food intake for 47% in control rats. Cecal ligation, and also the administration of LP, led to alterations of amino-acid metabolism. The most important changes were found in muscle free amino-acid concentrations with highly decreased levels of free glutamine. A glutamine deficiency is known to be related to a decreased rate of protein synthesis. The proteolytic rate in incubated soleus muscle was increased for 11.5% and even higher in LP-treated septic rats (+22%). It is concluded that the administration of LP cannot reverse protein catabolism in sepsis--possibly because LP does not influence those enzymes or proteases involved in tissue loss, or LP is inactivated by enzymes in rat tissues.

Amino Acids↗
PubMed1987

Free amino acid levels in muscle and liver of a patient with glucagonoma syndrome.

This study set out to measure the amino acid concentrations in the femoral artery, femoral vein, hepatic vein, muscular and hepatic tissue, and urine of a patient with the glucagonoma syndrome. The total plasma amino acid concentration was severely reduced on admission (737 mumol/L, 26% of normal), with only a slight increase during intravenous administration of 200 g of amino acids per day. The total intracellular amino acid levels in the muscle were 86%, and those of the liver were 47% of the normal range. Only 0.62% of the amino acids administered were found in the urine. Arteriovenous amino acid concentration differences across the muscle and splanchnic tissue indicated the release of amino acids (mainly glutamine, glycine, and alanine) from the muscle and the absorption of amino acids by the splanchnic bed. This study shows that the infusion of a high amount of amino acids cannot increase the subnormal plasma AA levels of patients with the glucagonoma syndrome. The low total plasma AA levels are paralleled by decreased intracellular free amino acid levels in the muscle and liver.

Adenoma, Islet Cell↗
PubMed1987

[Intracellular amino acid concentrations in various disease states].

The determination of free amino acids (AA) in human tissue is far more complicated than the analysis of plasma AA. The concentrations of free AA are different in plasma, liver and muscle, respectively. Pathological conditions like sepsis, liver failure and glucagonoma syndrome lead to characteristic alterations in the concentrations of free AA. However, the relationship between cytosolic AA concentrations and protein synthesis are not yet clear. Possibly drastically reduced levels of single AA (e.g. glutamine) lead to a 'down'-regulation of protein synthesis.

Amino Acids↗
PubMed1987

[Measuring blood flow and catheterization technic in the acute and chronic dog model].

Metabolic studies under in vivo conditions may require a simultaneous catheterization of various organs. Because of phylogenetic relationships, pigs or dogs are best suitable for metabolic investigations. Organ-specific flow rates and substrate balances can be determined by means of dye dilution techniques (indocyanine green - ICG, para-aminohippuric acid - PAH, bromsulphthalein - BSP). An easy method for catheter insertion under anesthesiological and operative conditions is described.

Animals↗