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H Graf

Publications and source records attributed to H Graf.

At least 127 records · Page 7Linked to original sources
PubMed1986

[The utilization of 15N-labeled urea by the laying hen. 3. Incorporation of labeled nitrogen into the amino acids of the white and egg yolk].

In an experiment with 3 colostomized laying hens the incorporation of heavy nitrogen from urea into the amino acids of the 21 eggs laid during the 8-day experiment was ascertained. In these eggs the content of 15 amino acids was ascertained separately in the whites and yolks of the eggs and their atom-% 15N-excess (15N') was determined. The heavy nitrogen could be detected in all amino acids investigated. The incorporation of 15N' into the essential amino acids of the white and yolk of eggs is very low. Of the applied 15N'-amount of the urea 0.18% could be detected in the 9 essential amino acids of the white of egg and 0.12% in those of the yolk. For the 6 analysed nonessential amino acids the rediscovery quota of 15N' in the white of egg was 0.50% and in the yolk 0.81%. The conclusion from these results is that the NPN-source urea is insignificant for egg protein synthesis.

Amino Acids↗
PubMed1986

Decreased serum interleukin 1 activity and monocyte interleukin 1 production in patients with fatal sepsis.

The role of interleukin 1 (IL 1) in 16 patients with sepsis and 16 normal controls was investigated. Thymocyte costimulation was used to assay in vitro IL 1 levels produced by adherent cells in the peripheral blood, and in vivo IL 1 levels in the serum. Adherent cells (i.e., monocytes) from nonsurviving septic patients produced significantly less IL 1 activity than cells from healthy controls or surviving patients, either spontaneously or by silica stimulation. In contrast, in vitro IL 2 production by T lymphocytes was not altered in septic patients. Serum IL 1 activity was determined using serum fractions from high-pressure liquid chromatographic gel filtration. Suppressor factors in healthy subjects as well as septic patients usually eluted at molecular weights above 50 kilodaltons, while IL 1-like activity was normally present between 35 and 1 kilodaltons. Sera of nonsurviving septic patients contained significantly less IL 1 compared to that of controls or surviving patients. Thus, decreased serum IL 1 levels and diminished monocyte production of IL 1 appear to be negative prognostic indicators, possibly reflecting a breakdown of mononuclear phagocytes.

Adult↗
PubMed1986

Depth-force-patterns in periodontal probing.

This investigation was undertaken to study penetration-depth and simultaneous force development during the insertion of a standard periodontal probe tip into a pocket to gain information about the tissue resistance to probing and its relation to the accuracy of depth determination. A piezoelectric force transducer and a linear position transducer were incorporated into a periodontal probe. Depth-force diagrams were obtained on an x-y plotter. In 5 patients requiring treatment for chronic periodontitis, 50 sites were selected and measured 3 times before and 3 times after a treatment phase consisting of hygiene instruction, systematic deep scaling and root planing. The minimal required probing force for reproducible values within a limit of 0.5 mm up to a force of 1.2 N was determined for each record ("b-value") and correlated in a multiple linear regression analysis with a number of clinical parameters of the sites. Depth-force diagrams recorded with the probe showed the characteristics of saturation curves flattening off in the range of 1 N and more. When the probing force was increased from 0.41 N up to 1.2 N, 50% of all measurements showed an increase in depth of more than 0.5 mm. However, increasing from 0.9 to 1.2 N resulted in a change of more than 0.5 mm in only 5% of the measurements. Differences in b-values before and after the treatment were significant (p less than 0.01). Differences related to tooth type (M, PM, I) and conventional pocket depth before treatment were also significant (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Influence of acute experimental hypercalcemia on peripheral insulin sensitivity in healthy subjects.

Since hypercalcemia is thought to have a modifying effect on glucose metabolism, the possible influence of experimental hypercalcemia on peripheral insulin reaction was investigated in 6 healthy control subjects by the euglycemic clamp technique. Each of these subjects was randomly tested twice, in the normocalcemic as well as in the hypercalcemic state (infusion of calcium gluconate 15 mg/kg body wt. over a period of 180 min). Infusion of calcium gluconate caused a 27% increase in plasma calcium levels, whereas the plasma phosphate levels were not significantly changed during the eucalcemic and hypercalcemic clamp protocol. Steady state plasma insulin levels and plasma glucose levels were nearly identical between the 2 clamp protocols. Exogenous hypercalcemia had no significant influence on peripheral glucose utilization measured by the M-value (M = 4.83 +/- 0.6 mg/kg body wt./min in the eucalcemic state, 4.77 +/- 0.7 mg/kg body wt./min in the hypercalcemic state, n.s.). The present data indicate that at least acute experimental hypercalcemia has no significant influence on peripheral glucose utilization.

Adult↗
PubMed1986

A new algorithm for individual dialysis prescription based on urea kinetics.

Methods for calculating required dialysis time to maintain certain blood urea nitrogen levels predialytically thus far have neglected the influence of ultrafiltration during hemodialysis and of weight changes in the interdialytic period. We therefore have developed a new algorithm for individual dialysis prescription based on urea kinetics which further optimizes accuracy of dialysis prescription by considering these two factors. The accuracy of this new method was proven in a prospective follow-up of 3 patients during some 9 consecutive hemodialysis session. It was found that there was a very close relation between the measured and the predicted values of blood urea nitrogen, the difference being only due to variations in dietary protein intake as the patients were kept on liberal food intake. The new algorithm is easily implemented into a pocket calculator and thus can be used under arbitrary dialysis conditions.

Algorithms↗
PubMed1986

Effect of metformin on peripheral insulin sensitivity in non insulin dependent diabetes mellitus.

To test whether metformin treatment might improve peripheral insulin sensitivity in non insulin dependent diabetes, we measured peripheral glucose uptake in 12 non insulin dependent diabetics before (A) and after 4 weeks (B) of metformin therapy (2 X 850 mg/day) by the hyperinsulinemic clamp technique (80 mU/m2/min). In addition, insulin binding to monocytes was compared between A and B. Diabetic control, evaluated by measurement of fasting blood glucose and glycosylated hemoglobin, was significantly improved by metformin treatment (P less than 0.01). Insulin binding to monocytes was not significantly influenced by metformin (A-4.53% vs. B-5.12%, n.s. at insulin tracer concentration). Peripheral glucose utilisation improved slightly, but significantly after 4 weeks of metformin therapy (A: 4.4 +/- 0.6 mg/kg/min, B: 5.4 +/- 0.8 mg/kg/min, p less than 0.01). Improvement in peripheral glucose utilisation correlated significantly with improved metabolic control, estimated by fasting blood glucose measurements (p less than 0.01).

Adult↗
PubMed1985

[Individual dialysis using computer-controlled prescription].

The use of urea kinetics as basis for optimization and individualization of renal replacement therapy has become quite popular over the last decade. The rationale underlying the use of blood urea nitrogen for monitoring or targeting dialysis therapy is based on the report of an American multicentre cooperative dialysis study showing that blood urea nitrogen concentrations are closely correlated to the occurrence of morbidity and complications in dialysis patients. In order to further optimize the accuracy of dialysis prescription we have developed a new algorithm for estimation of the dialysis time needed to reach a certain blood urea nitrogen concentration, which--in contrast to all methods employed so far--enables accurate calculation of ultrafiltration during haemodialysis and of weight changes in the interdialytic period.

Blood Urea Nitrogen↗
PubMed1985

Evidence for a detrimental effect of bicarbonate therapy in hypoxic lactic acidosis.

Lactic acidosis, a clinical syndrome caused by the accumulation of lactic acid, is characterized by lactate concentration in blood greater than 5 mM. Therapy usually consists of intravenous sodium bicarbonate (NaHCO3), but resultant mortality is greater than 60 percent. The metabolic and systemic effects of NaHCO3 therapy of hypoxic lactic acidosis in dogs were studied and compared to the effects of sodium chloride or no therapy. Sodium bicarbonate elevated blood lactate concentrations to a greater extent than did either sodium chloride or no treatment. Despite the infusion of NaHCO3, both arterial pH and bicarbonate concentration decreased by a similar amount in all three groups of dogs. Additional detrimental effects of NaHCO3 were observed on the cardiovascular system, including decreases in cardiac output and blood pressure that were not observed with either sodium chloride or no treatment. Thus there is evidence for a harmful effect of NaHCO3 in the treatment of hypoxic lactic acidosis.

Acidosis↗
PubMed1985

Glucose metabolism and insulin sensitivity in patients on chronic hemodialysis.

In order to evaluate the potential role of parathyroid hormone on glucose metabolism in patients on chronic hemodialysis hyperglycemic clamp studies were performed in 7 parathyroidectomized and 11 nonparathyroidectomized patients on chronic hemodialysis and in healthy controls. There were no significant differences in the peripheral glucose uptake of the 3 groups. The beta cell response to hyperglycemia during the early phase as well as during the steady state was almost identical in controls and in nonparathyroidectomized uremics, whereas in the parathyroidectomized group a markedly enhanced insulin secretion was found. Calculated tissue sensitivity to insulin therefore was equal in controls and in nonparathyroidectomized uremics, whereas patients after parathyroidectomy had peripheral insulin resistance. Our results demonstrate that patients on chronic hemodialysis apparently have normal peripheral glucose uptake. The subgroup of patients who have undergone parathyroidectomy, however, show an enhanced insulin response to hyperglycemia suggesting peripheral insulin resistance. We conclude that longstanding and severe secondary hyperparathyroidism--the usual cause for parathyroidectomy in these patients--results in irreversible insulin resistance with a compensatory increase of insulin secretion.

Adult↗
PubMed1985

Metabolic effects of sodium bicarbonate in hypoxic lactic acidosis in dogs.

The metabolic effects of NaHCO3 therapy in hypoxic lactic acidosis were evaluated in the anesthetized dog. Hypoxic lactic acidosis was induced by ventilating the dogs with a hypoxic gas mixture of 8% O2/92%N2, resulting in arterial PO2 of less than 30 mmHg, pH below 7.20, bicarbonate less than 12 mM, and lactate more than 7 mM. In this situation lactate accumulates because of overproduction of lactate by gut and carcass in the presence of a diminished capacity of the liver to extract lactate. After the development of hypoxic lactic acidosis the dogs were treated for 60 min with either NaHCO3 or NaCl or had no therapy. Sixty minutes of either treatment resulted in further declines of blood pH and bicarbonate that were similar in all three groups. NaHCO3-treated animals, however, showed an increase in blood lactate that were significantly higher than those treated with NaCl or those that had no therapy. This could be explained by a significantly higher gut lactate production with NaHCO3 therapy than in the NaCl-treated group. Concomitantly NaHCO3-treated animals showed a decrement in liver and gut blood flow that did not occur with NaCl treatment. Only NaHCO3 therapy was associated with a further decrease of liver intracellular pH, which could be attributed to both an increase in the CO2 load to the liver and increased tissue lactate levels, which were not observed with NaCl or no therapy. Additionally, liver lactate extraction was not improved by administration of NaHCO3 or NaCl.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis↗
PubMed1985

Effects of dichloroacetate in the treatment of hypoxic lactic acidosis in dogs.

The metabolic and systemic effects of dichloroacetate (DCA) in the treatment of hypoxic lactic acidosis were evaluated in the dog and compared with the infusion of equal quantities of volume and sodium. Hypoxic lactic acidosis was induced by ventilating dogs with an hypoxic gas mixture of 8% oxygen and 92% nitrogen, resulting in arterial PO2 of less than 30 mmHg, pH below 7.20, bicarbonate less than 15 mM, and lactate greater than 7 mM. After, the development of hypoxic lactic acidosis dogs were treated for 60 min with either DCA as sodium salt or NaCl at equal infusions of volume and sodium. Dogs treated with DCA showed a significant increase of arterial blood pH and bicarbonate, and steady levels of lactate, whereas NaCl resulted in further declines of blood pH and bicarbonate, and rising blood lactate levels. Overall lactate production decreased during therapy with either regimen, but hepatic lactate extraction increased significantly with DCA, while it remained unchanged with NaCl. Tissue lactate levels in liver and skeletal muscle decreased significantly with DCA treatment but were unchanged with NaCl. Additionally, an increase in muscle intracellular pH was observed only in DCA treated dogs. A possible mechanism for the observed actions of DCA might be related to a significant increase in oxygen delivery to tissues. Such an effect was found with DCA administration, but was not observed with NaCl therapy. In conclusion, DCA therapy in hypoxic lactic acidosis has beneficial systemic effects compared with therapy with NaCl. DCA administration is accompanied by increases of blood pH and bicarbonate, a decrease in lactate production, and enhanced liver lactate extraction, and a lowering of tissue lactate levels.

Acetates↗