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Biomedical subjects

P Jürgens

Publications and source records attributed to P Jürgens.

At least 19 recordsLinked to original sources
PubMed2002

[Speech outcome after simple and multiple cleft palate operations].

OBJECTIVES: If the primary palatal closure in a patient with cleft lip and palate is unsuccessful, defects such as palatal fistulas and a short velum have to be corrected by secondary operations. It is an informal belief among surgeons that these reoperations can have detrimental effects on the patients' nasal resonance and articulation. It was our aim to critically evaluate the validity of this belief. MATERIAL AND METHODS: One hundred and twenty-four patients with cleft lip and palate were divided into three groups. The 70 patients in group 1 had only undergone a primary palatal closure operation. The 33 patients in group 2 had undergone one or more palatal reoperations. The 21 patients in group 3 had undergone an additional pharyngeal flap operation. Resonance and articulation were evaluated perceptually. Nasalance was assessed with the NasalView system, and the mean speech rate was analyzed with the MODIAS software. RESULTS: There were no significant differences for any of the speech measures between groups 1 and 2. Patients in group 3 had significantly worse results for all speech measures. CONCLUSIONS: The speech outcomes for patients with multiple palatal reoperations were no different from those of patients with single palatal closure operations. The pharyngeal flap operation did not lead to sufficient improvements in the speech of the patients in group 3.

Adolescent↗
PubMed1997

[Plasma amino acid concentrations and isoleucine-phenylalanine quotient in patients with acute myocardial infarct during amino acid infusion].

AIM: The influence of substitution with two different amino acid solutions on changes in plasma amino acids were studied in patients with acute myocardial infarction. PATIENTS AND METHODS: Thirty consecutive patients admitted to an intensive care unit were included in this open, nonrandomized study. The isoleucine-phenylalanine-concentration ratio was calculated. Patients of the treatment groups received 10 ml/kg BW/24 h of 10% amino acid solutions intravenously (1 g/kg BW/24 h). Patients of group 1 received Intrafusin 10%, patients of group 2 Aminosteril 10%. Ten patients (group 3) were infused with 10 ml/kg BW/24 h isotonic electrolyte solution (Jonosteril and served as a control group. All infusions were performed over a 96 hour period. RESULTS: All infusion of amino acid solutions increased the plasma concentrations of most amino acids without a significant impact on the pattern of amino acids over time. Significant increases in plasma concentrations together with a significant variation over time were observed for glycine, isoleucine, proline, alpha-amino-butyric-acid and glutamine. A significant difference in relation to the type of amino acid solution was observed for isoleucine and proline (rapid increase and higher concentrations with Aminosteril), and glutamine (rapid increase and higher levels with Intrafusin). CONCLUSION: The isoleucine-phenylalanine-ratio increased from initially decreased values between 0.9 and 1.0 during amino acid infusion and reached the level of 1.25 found in healthy persons in patients with Intrafusin infusions.

Aged↗
PubMed1997

New aspects on etiology, biochemistry, and therapy of portal systemic encephalopathy: a critical survey.

There is scientific agreement that portal systemic encephalopathy (PSE) is caused morphologically by portal systemic shunts and biochemically by constituents of the portal venous blood. Ammonium has a key role in the pathogenesis of PSE. Direct correlations with the degree of PSE have been established exclusively with glutamine, i.e. the terminal product of the peripheral detoxification of ammonium. In PSE, ammonium is probably responsible for damage to astrocytic and neuronal cells. Ammonium's toxic effect is due to the intracerebral glutamine synthesis. After several metabolic steps, which will be discussed in detail, brain cell damage is caused directly or indirectly (exitotoxically) by energy deficiency. Hyperammonemia and PSE are each well defined though different forms of disturbance. Therefore, ammonium is not the sole decisive factor in the pathogenesis of PSE. We performed a detailed and critical analysis of all studies on amino acid therapy of PSE, especially those that were randomized and controlled. This analysis revealed a close and direct correlation between qualitative and quantitative dosages of amino acids on one hand, and parallel improvements of amino acid imbalance (essentially associated with PSE) and degree of PSE on the other. A close and direct dose/efficacy correlation must be assumed. Disturbed plasmatic amino acid homeostasis and cerebral monoaminergic neurotransmission are probably important pathogenic factors of PSE. A fundamental cofactor in the efficacy of each adequate amino acid therapy might be a substantial decrease of endogenous ammonium production. Physiologic benzodiazepines may also have an important function in the pathogenesis of PSE: not so, however, the glutamate-ergic and GABA-ergic neurotransmission, which are disturbed principally in PSE. In close correlation to pathogenesis, established and proposed therapies of PSE are critically discussed.

Amino Acids↗
PubMed1993

[Behavior of plasma proteins and nitrogen balance in patients with acute myocardial infarct with and without intravenous amino acid administration].

OBJECTIVE: The goal of this study was to examine the behaviour of nitrogen balance and plasma proteins with or without intravenous supply of amino acids in patients with acute myocardial infarction. DESIGN AND PATIENTS: 30 consecutive patients who suffered from acute myocardial infarction and who were admitted to our medical intensive care unit were examined in an open, non-randomised study. SETTING AND INTERVENTIONS: The first 10 patients (group I) received 10% Intrafusin 10 ml/kg BW/24 h as a continuous intravenous infusion over a period of 96 h. Patients No. 11-20 (group II) received Aminosteril 10% 10 ml/kg BW/24 h also over a 96-hour period. Patients No. 21-30 (group III) were given intravenous infusions of Jonosteril 10 ml/kg BW/24 h for 96 h. RESULTS: The nitrogen balance demonstrated a statistically significant decrease in all groups (group I, 9.1 to 6.1 g/day; group II, 9.8 to 4.8 g/day; group III, 1.3 to -1.1 g/day); however, in groups I and II the nitrogen balance remained positive. The concentrations of total protein, transferrin, retinol-binding protein and pre-albumin decreased significantly. This decrease, however, was significantly less in patients given amino acid infusions. CONCLUSIONS: Infusion of amino acids in acute myocardial infarction results in a positive nitrogen balance and reduces the decrease in plasma protein concentrations. Further studies are required to judge the positive nutritive effect of amino acid infusions on the outcome of myocardial infarction.

Acute-Phase Proteins↗
PubMed1988

[Taurine--recent views and importance for artificial feeding].

Taurine is an important age- and compartment-specific part of the pool of free amino acids in all human tissues and fluids examined. Besides an active taurine transport system, the mechanisms to assure compartment-specific taurine-homeostasis in humans is presumably due to a compartment-specific taurine synthesis. By the identity of cysteine-sulfinic acid - and glutamate-oxalate transaminase as well as of cysteine-sulfinic acid - and glutamic acid decarboxylase taurine biosynthesis via cysteine-sulfinic acid shows direct metabolic relationship between biochemical pathway of cysteine-sulfinic acid and taurine on one side, and of the dicarbonic acid and their biological decarboxylates on the other side. In the parenteral and enteral nutrition of premature babies as well as of adults with portosystemic encephalopathy or with extreme thiamine deficiency, there is - besides an inconstant parallel of exogenous taurine supply and plasma taurine homeostasis - a constant parallel between definitely lowered plasma taurine concentrations and comparably distinct disturbance of the homeostasis of the dicarbonic acids and/or their biosynthetic products. A metabolic connection seems likely. The hypothesis of Sturman et al. in 1976 that taurine is an essential part of the human nutrition at least in the premature or full-term newborn phase of life could not be supported in the subsequent studies of different groups of authors - neither in relation to the nitrogen balance, childhood-development, hepatic cellular function, biliary-acid metabolism, intestinal fat absorption nor any organ-specific function. The nutritional value of taurine in humans still remains unclear in regard to specific physiologic as well as specific pathophysiologic phase of metabolism.

Humans↗
PubMed1986

[Branched-chain amino acids in the treatment of latent porto-systemic encephalopathy. A placebo-controlled double-blind cross-over study].

In a doubleblind cross-over placebo-controlled trial the efficiency of oral treatment with branched chain amino acids was investigated in 22 inpatients with liver cirrhosis. In all patients evidence of latent (subclinical) portalsystemic encephalopathy was obtained by using an extensive psychometric test programme. Patients received a defined diet of 35 cal/kg/day containing 1 g of protein. In addition, branched chain amino acids or casein in a dosage of 0.25 g/kg/day was administered in a cross-over fashion, each for 1 week. Semiquantitative nitrogen balance increased during both treatments, with a tendency towards a larger increase during branched chain amino acid treatment. At the same time ammonia concentration tended to decrease during branched chain amino acid treatment. Taking into account the cross-over design, significant improvements attributable to branched chain amino acid treatment could be demonstrated in psychomotor functions (line tracing, tapping, steadiness, auditory reaction time), attention (digit table), and practical intelligence (digit symbol, number connection test).

Administration, Oral↗
PubMed1985

Branched chain amino acids in the treatment of latent portosystemic encephalopathy. A double-blind placebo-controlled crossover study.

Branched chain amino acids have been recommended for the treatment of portosystemic encephalopathy based on the false neurotransmitter hypothesis. This hypothesis implies that by correction of the deranged amino acid pattern in the blood of cirrhotics, false neurotransmission and then portosystemic encephalopathy is improved. We conducted a double-blind crossover placebo-controlled trial in 22 inpatients with liver cirrhosis and obtained evidence of latent (subclinical) portosystemic encephalopathy using an extensive psychometric test program. Patients received a defined diet of 35 cal/kg X day containing 1 g of protein. In addition, branched chain amino acids or casein in a dosage of 0.25 g/kg X day was administered in a crossover fashion, each for 1 wk. Semiquantitative nitrogen balance increased during both treatments, with a tendency of a larger increase during branched chain amino acid treatment. At the same time ammonia concentration tended to decrease during branched chain amino acid treatment. Taking into account the crossover design, significant improvements attributable to branched chain amino acid treatment could be demonstrated in psychomotor functions (line tracing, tapping, steadiness, auditory reaction time), attention (digit table), and practical intelligence (digit symbol, number connection test).

Adult↗
PubMed1984

[Animal experiment studies of chronic thiamine deficiency. Changes in carbohydrate and amino acid metabolism under resting and load conditions].

The metabolic effects of thiamine deficiency on the metabolism of lactate, acid-base and amino acids were evaluated both with and without muscular exercise in a controlled animal experiment. Thiamine deficiency - in good correlation with its biologic halftime and also with reports in the literature - caused with a latency of 17-56 days and statistically proven in parallel the following effects: hyperlactemia; in comparison to controls elevated plasma concentrations of threonine, alanine, glutamic acid, glutamine, histidine, methionine, taurine, valine, isoleucine and leucine; distinctly lowered - also in comparison to controls - plasma concentrations of arginine and tryptophan. Furthermore, in the thiamine deficient rats predetermined muscular exercise caused the following effects, also occurring concomitantly: life threatening lactacidosis; marked - statistically prover - disturbance of the homeostasis of alanine, glycine, methionine and arginine; distinctly - and statistically significant - elevated plasma concentration of proline; statistically significantly lowered plasma concentrations of taurine. The reasons for all these changes under thiamine deficiency is most likely a metabolic one primarily due to a disturbance of the utilization of pyruvate in the liver. An additional disturbance of both the transsulfuration pathway and the Krebs-Henseleit-cycle seems probable. The physiologic regulation of pyruvate, lactate, alanine, serine and tyrosine during muscular exercise in correlation to the controls is being discussed.

Amino Acids↗
PubMed1982

[Total parenteral nutrition of premature infants: metabolic effects of an exogenous supply of L-aspartic acid and L-glutamic acid].

Within the scope of clinically indicated total parenteral nutrition of premature infants, a comparative randomized study was performed to examine--by means of nitrogen-balance studies and determination of the free amino acids in the serum--the metabolic effects of absent or parallel intake of 1.140 mumol L-aspartic acid plus 2.160 mumol L-glutamic acid per kg body weight per day in complete L-amino acid solutions with a comparative E/T-ratio and with identical intake of all other nutrients adapted to the requirement. 1. The nitrogen balance level was not affected by the absent or parallel intake of the dicarbonic acids. 2. Intravenous intakes of glycine plus L-serine, which are higher than 2.5 mmol per kg body weight and day, caused statistically significant increased serum concentrations of glycine and L-serine. Such intakes are obviously above the physiologic regulation range. 3. The absent intake of L-aspartic acid and L-glutamic acid resulted in parallel, statistically significant reduced serum concentrations of aspartic acid and asparagine as well as in homeostatic serum concentrations of glutamic acid and glutamine. Despite the only 15-20% higher intake of proline, alanine and arginine under the infusion regimen lacking dicarbonic acids, there was a parallel, statistically significant marked increase in the serum concentrations of proline, alanine, arginine and methionine as well as a statistically significant marked decrease in those of taurine. Under the infusion regimen containing dicarbonic acids exclusively, constant homeostatic serum concentrations of these amino acids as well as of aspartic acid and glutamic acid were measured. 4. A direct or indirect effect of the exogenous supply of L-aspartic acid and/or L-glutamic acid on the homeostasis of aspartic acid and asparagine, on the endogenous turnover of L-alanine and L-proline as well as on the physiologic course of the Krebs-Henseleit cycle and of the "transsulfuration pathway" must be discussed. 5. Since the supply rates of L-aspartic acid plus L-glutamic acid chosen in series 2 (when continuously administered during 24-hour periods) apparently do not cause any disturbance in amino-acid homeostasis, it is established that under the nutritional conditions given this intake lies within the respective physiologic regulation range and therefore is atoxic.

Amino Acids↗
PubMed1982

[Postoperative amino acid metabolism].

According to literature, anabolism is present in the visceral organs also during stress and early poststress-periods. During early periods of fasting, those enzyme structures of the visceral organs which are of prime importance are being catabolized. Therefore, an adequate nutrition is not only reasonable, but obligatory especially in those patients severely ill. As for the parenteral management of protein nutrition, solutions of L-amino acids (a.a.) are the only types suitable. These solutions should contain at least proportionate quantities of the 8 essential a.a., histidine, arginine, proline, alanine, glutamic acid and glycine with each single a.a. being within the respective physiologic regulation range. Different pattern of the a.a. requirement of adults are being established for different metabolic conditions. These types of a.a. pattern are highly dependent on the alterations of the functional requirement of one or more a.a. For the clinical need of total parenteral nutrition (t.p.n.) of adults, at least 3 types of different compositions of L-a.a. solution should be available: a) a standard a.a. solution (adapted to the physiologic requirement of adults) for long-term t.p.m. b) an a.a. solution with a high E/T-ratio for the t.p.n. of uremic patients (this solution is the one also used for t.p.n. of infants), c) an a.a. solution with high concentrations of branched-chain a.a. for the therapy of portosystemic encephalopathy. The metabolic significant and clinical importance of other special a.a. solutions are discussed.

Adult↗
PubMed1982

[Disorders of amino acid metabolism in a patient with identified thiamine deficiency].

Report on a serious disturbance of amino-acid metabolism in a 56 year old male patient suffering from thiamine-(vitamin B-1) deficiency, as proven by clinical history and examination and by laboratory data. In comparison with a group of 75 normal male persons also evaluated by the same laboratory this patient--while thiamine deficient--had markedly elevated serum concentrations outside the physiologic range of glutamic acid, glutamine, proline, citrulline, ornithine, histidine, lysine, phenylalanine, tyrosine and leucine, whereas his serum concentrations of taurine, serine and isoleucine were comparably definitely lowered. Following six to seven days of daily i.m. injections of 200 mg of thiamine each, this imbalance of amino-acid homeostasis disappeared except for that of taurine and--questionably--that of phenylalanine. In view of the absence of other exogenous or endogenous potential causes for this, it must be presumed that the thiamine-pyrophosphate deficiency caused the imbalance of amino-acid metabolism by consecutively disturbing the function of the alpha-ketoglutarate-, pyruvate- and p-hydroxy-phenylpyruvate- decarboxylase chains respectively. Possible connections between thiamine-deficiency and lowered serum concentrations of serine, taurine and isoleucine are being discussed.

Amino Acids↗
PubMed1980

Coagulation parameters and heparin levels in open-heart surgery.

Coagulation parameters were studied during open-heart surgery. Severe reduction of the platelet count and of several other clotting factors was observed. The half-rate of heparin varied threefold in the patients. This may indicate that the dosage of protamine chloride prior to the end of the surgical procedure has to be adjusted to the individual heparin levels.

Antithrombin III↗