Biomedical subjects
Publications and source records attributed to R H Ackermann.
A report is made on the manifestation of diabetes insipidus (neuropituitary syndrome), observed six days after a Caesarean section (29-years old I. Gravida). The progress of pregnancy and delivery as well as the successful treatment with Desmopressin (Minirin) post partum are described. The aetiology is still obscure.
After endocrinological and radiological evaluation of a hyperprolactinemia 13 patients became pregnant under bromocriptine therapy. In two of these patients a selective adenomectomy was performed by the transphenoidal route because of a prolactin (PRL) secreting adenoma. In 12 patients the pregnancy was not complicated. The serum PRL levels were different but mostly in a normal range. The control of x-ray and visual field in patients with a rapid increase of the PRL levels did not result in a tumor recurrence. After a normal course of the serum PRL concentrations one patient with a microadenoma developed suddenly a chiasma syndrome in the 31th week of gestation. The further evaluation resulted in a pituitary tumor with suprasellar extension. The discrepancy between the radiological result and the normal serum PRL levels was explained by a hemorrhage into the adenoma. After the operation the chiasma syndrome was reversible within a short period. Altogether, the course of the pregnancies was not complicated. We did not see fetal malformations. Post partum the sella x-ray of all patients did not reveal any significant changes so far.
The well-known rise of the levels of glucose, lactate, pyruvate, non-esterified free fatty acids (NFFA), glycerol, and ketone bodies during labour cannot be explained only by metabolic pathways. The simultaneous measurement of insulin, cortisol, hGH, and prolactin shows a striking change in secretion, especially of cortisol, after the first half of labour. It is assumed that cortisol plays an important part in the intrapartal metabolic conversions. The correlation cortisol/glucose becomes significant. There is no evidence of the known catabolic effect of cortisol under the conditions of labour, but these is evidence of a reduction of peripheral glucose utilisation. The role of cortisol for the intrapartal metabolic changes is discussed under the aspect of labour progress. The outlines of a very ingenious but also complex interplay between endocrinological and metabolic factors emerge which may provide useful tools for therapeutic use.
After a 5-day preoperative preparing period, 24 metabolically healthy patients, who had to undergo gastric resection, were fed postoperatively by hypocaloric total parenteral nutrition for a 5-day period. Group I, n = 13; received 0.11 g Xylitol/kg BW . h; Group II, n = 11, received 0.11 g Glucose/kg BW . h. Both groups received 1.71 g L-crystalline amino acids/kg BW . day. During the whole postoperative period, group II had significantly higher serum glucose and insulin levels. Due to the high postoperative insulin concentration in group II, free fatty acids, acetoacetate, beta-hydroxybutyrate and branched chained amino acids were significantly lower. The augmented release of muscle amino acids and the covering of a part of the energy expenditure by increased fatty acid oxidation in group I led to a higher postoperative synthesis rate of visceral proteins. From postoperative day 3 on transferrin and from postoperative day 6 on albumin and total protein were significantly higher in group I. This study could demonstrate that due to its special role in the intermediary metabolism during the postoperative period xylitol leads to a significantly higher regeneration rate of visceral proteins compared to glucose during total parenteral nutrition.
As previously observed after infusions of glycerol, fructose infusions with rates above the average maximal turnover capacity (3.5 g X kg-1 X h-1) result in damage of the kidneys as shown by a decrease of the total activity of glycerokinase and fructokinase and excretion of glycerokinase in the urine. Beginning alterations of the kidneys are dependent on time and dose become evident by a depletion of protein per gram fresh weight. In the beginning of the changes the total activity of enzymes in the kidneys remaining constant. Interrelations between the observed kidney alterations, turnover capacity, substrate concentrations in the blood, and the rate of renal excretion are discussed with regard to the results after infusions of glucose and mannitol. For infusion therapy it can be deduced, that dosage in borderline cases should be determined by the blood level of the substrate rather than by body weight, if undesirable effects are to be avoided.
The levels during and following delivery are investigated of the unesterified fatty acids (UFS), of the prostaglandin precursors arachidonic and Dihomo-gammalinolenic acids and of their possible essential precursor oleic acid. The summation curve of the total fraction of the unesterified fatty acids contains different patterns of different fatty acids. 24 hours after delivery only oleic acid and arachidonic acid are significantly increased. The patterns of glycerine, the triglycerides and the ketone bodies, the acetate and the beta-hydroxy butyrate show the different changes of the fatty acids in correlation to lipolysis, to beta-oxidation rate of fatty acids, to lipogenesis and to an increased turn over of prostaglandins.
The mean maximal turnover capacity for intravenously infused xylitol was determined in women during parturition and after surgery. Although both conditions are considered as stress situations, the values for maximal turnover differed by 100%. The mean maximal turnover under labour was 0.31 g/kg/h compared to 0.76 g/kg/h on the first day after surgery.
The decrease of ATP-concentration in tissues after rapid intravenous injection is not specific, neither with regard to the organ nor with regard to the substrate. It can be achieved by any substrate which is channeled into metabolism by phosphorylation or activation using ATP, if the organ has the appropriate enzymatic outfit.
The steady-state blood level of fructose during 24 hours intravenous infusion in response to different doses follows saturation kinetics. Even after toxic doses of 1.5 g/kg/h no depletion of liver adenine nucleotides can be observed after 24 hours. In the kidneys, however, ATP, ADP and total adenine nucleotides were decreased after a dose of 1.5 g/kg/h of fructose. The blood glucose increased continuously at infusion rates of 1.5 g/kg/h. Inorganic phosphate in the blood increased at doses of 1.0 and 1.5 g/kg/h. The weight of the kidneys increased, presumably through water uptake. Urinary secretion was drastically reduced at doses above 1.0 g/kg/h. An appreciable activity of ketohexokinase can be demonstrated in the kidneys.
Effects of intravenous glycerol infusions on glycerol kinase and adenosintriphosphate in rat kidneys. Intravenous infusions of glycerol with rates near and above the average maximal turnover capacity (0,74 g.kg-1.h-1) cause alterations of the kidneys such as weight increase, decrease of protein content and activity of glycerol kinase with excretion of this enzyme in the urine. At infusion rates of 0,6 g.kg-1.h-1 and more a decrease of the ATP-content of the kidneys is observed. Effects on the liver are not consistent and only demonstrable at infusion rates above the maximal turnover rate of glycerol. The results are discussed with regard to osmotic nephrosis. The appearance of glycerol kinase in the urine is discussed as an early symptom of kidney damage.
During continuous infusions of 24--48 hours, glycerol utilization and turnover capacity in rats were estimated in a range from physiological to toxic doses. Total clearance, elimination constant, half life, transfer and pool size were calculated for various rates of infusion as well as for the endogenous turnover. With increasing blood level, the turnover rate rises like an enzyme saturation curve, first rapidly and then ever more slowly to a maximum value. Therefore, the steady state blood levels do not increase linearly with the infusion rate. The renal excretion of glycerol is below 1 per cent of the supply up to rates of infusion of 0.4g with kg-1 with h-1. Even beyond the upper limit of the metabolic turnover a steady state is reached due to the high renal excretion. Beginning with 2 mumol/ml the excretion rises linearly with the blood level. At rates higher than 0.5g with kg-1 with h-1 the individual differences of the steady state levels are high. A significant negative correlation between the steady state levels of glycerol in blood and the activity of glycerol kinase in the liver and kidneys was observed. Necroses of the renal tubuli were found at infusion rates exceeding the turnover capacity in animals with low enzyme activity. The conclusions which may be drawn from these data regarding the parenteral supply of energy-yielding substrates are discussed.
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