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Biomedical subjects

A Lohninger

Publications and source records attributed to A Lohninger.

At least 37 records · Page 2Linked to original sources
PubMed1986

Studies on the effects of betamethasone, L-carnitine, and betamethasone-L-carnitine combinations on the dipalmitoyl phosphatidylcholine content and phosphatidylcholine species composition in foetal rat lungs.

Administration of L-carnitine or betamethasone to pregnant rats failed to increase either the total phospholipid or dipalmitoylphosphatidylcholine (DPPC) contents in foetal rat lungs on the 20th day of gestation, compared to controls. The combined administration of betamethasone (0.3 mg/kg) and L-carnitine (80 mg/kg) resulted in a pronounced increase of dipalmitoylphosphatidylcholine (7.8 +/- 2.5 mg/g dry weight) compared with the control group (5.4 +/- 1.8 mg/g dry weight), and compared with the groups receiving betamethasone (5.9 +/- 1.9 mg/g dry weight) or L-carnitine (5.6 +/- 1.5 mg/g dry weight) alone. The proportion of dipalmitoylphosphatidylcholine in the phosphatidylcholine species increased from 20.9 +/- 2.1% in the foetal lungs of the control group to 22.6 +/- 5.0% in the L-carnitine group, to 24.3 +/- 3.3% (p less than 0.01) in the betamethasone-L-carnitine (20 mg/kg) group, to 25.2 +/- 3.5% (p less than 0.01) in the betamethasone group, to 27.1 +/- 2.6% (p less than 0.01) in the betamethasone-L-carnitine (40 mg/kg) group, and to 28.4 +/- 3.7% (p less than 0.01) in the betamethasone-L-carnitine (80 mg/kg) group, while the palmitic acid portion in the phosphatidylcholine fatty acids was nearly unchanged. A pronounced increase of palmitoyl-myristoyl phosphatidylcholine (PC-30), the second disaturated phosphatidylcholine species present in lungs in significant amounts beside dipalmitoylphosphatidylcholine, was noted only in betamethasone treated animals. Furthermore, after betamethasone and betamethasone-L-carnitine treatment, a significant diminution (p less than 0.01) of the proportion of palmitoyl-palmitoleyl phosphatidylcholine (16 : 0/16 : 1-PC) in the phosphatidylcholine species was demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

The assessment of foetal lung maturity by chemical analysis of amniotic fluid.

Advances in the understanding of the neonatal respiratory distress syndrome have led to a proliferation of amniotic fluid tests. Measurement of pulmonary surfactant production is the most direct means of assessing pulmonary maturity. Assays of surfactant are subjected to certain pre-analysis sources of variation, such as variability in amniotic fluid volume, sample collection site, centrifugation speed and time, and contamination with blood and/or meconium. Amniotic fluid surfactant assays can be divided into biochemical and functional tests. When properly performed, both approaches yield results that correlate well with clinical findings. However, no single method has achieved the distinction of total reliability and universal applicability. In most tests the value for mature lungs is almost 99% accurate. On the other hand, immature values have very low accuracy. Therefore, it is advisable to perform an additional test or to repeat the determination. The determination of the lecithin/sphingomyelin ratio is characterized by sufficient accuracy for routine analyses. For scientific studies we recommend the use of a capillary gas-chromatographic method allowing an accurate assessment of dipalmitoylphosphatidylcholine, the most important surfactant constituent.

Amniotic Fluid↗
PubMed1984

Comparison of the effects of betamethasone and L-carnitine on dipalmitoylphosphatidylcholine content and phosphatidylcholine species composition in fetal rat lungs.

Antepartum administration of L-carnitine to pregnant rats results in an increase of both total phospholipid (80 +/- 11 mg/g dry weight (dw); mean +/- SD) and dipalmitoylphosphatidylcholine (DPPC) content (7.7 +/- 2.1 mg/g dw) in fetal lungs as compared to controls (72 +/- 10 and 7.0 +/- 2.5 mg/g dw, respectively). On the other hand, no effect of L-carnitine could be demonstrated on the DPPC portion in the total phosphatidylcholine (PC) or on the portion of palmitic acid in the PC fatty acids. Betamethasone elevated the DPPC content in fetal lungs (8.1 +/- 2.0 versus 7.0 +/- 2.5 mg/g dw in the controls), while total phospholipid content remained unaffected (71 +/- 19 versus 72 +/- 10 mg/g dw). The portion of DPPC in the PC species increased significantly (p less than 0.01) from 27.6 +/- 4.5 in the fetal lungs of the control group to 34.2 +/- 3.3 in the lungs of the betamethasone-treated group, while the palmitic acid portion in the PC fatty acids was nearly unchanged (45.9 +/- 3.2 versus 43.9 +/- 2.6 in the controls). Further, after betamethasone treatment, a significant diminution (p less than 0.01) of the monoenic PC 32 species (palmitoyl-palmitoleyl PC and palmitoleyl-palmitoyl-PC) and the PC 34 species (consisting primarily of palmitoyl-oleoyl-PC) could be demonstrated both in absolute and relative terms. This is in agreement with a significant reduction of the portions of palmitoleic (p less than 0.01) and oleic (p less than 0.05) acids in the total PC fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

[lst report: Alternatives to cortisone therapy. lst clinical experiences with a carnitine-betamethasone combination for the stimulation of fetal lung maturity].

In the recent past criticism has been voiced with regard to the efficacy and possible side effects of corticosteroid prophylaxis of fetal respiratory distress syndrome (RDS). Apparently the efficacy of this treatment has been over-estimated and the spectrum of possible side effects has not received enough critical attention. In view of the multiple indications that the fetal metabolism, above all, may be altered by this type of therapy, it seems necessary to search for other methods of surfactant stimulation. This paper presents the first clinical study on the use of carnitine (4 g for 5 days in combination with twice 8 mg beta-methasone versus twice 8 mg betamethasone alone). The patients on combination therapy showed a more marked increase in surfactant content of the amniotic fluid. Lung compliance determination in infants born within 72 hours of completion of therapy also revealed better results in the combination therapy group. There were also fewer clinically demonstrable RDS cases in this group. More research will be necessary to definitely establish the value of this new form of therapy.

Animals↗
PubMed1983

Relationships among human amniotic fluid dipalmitoyl lecithin, postpartum respiratory compliance, and neonatal respiratory distress syndrome.

The major molecular species of amniotic fluid phosphatidylcholine were determined as diacylglycerol trimethylsilyl ether derivatives by gas-liquid chromatography with use of glass capillary columns. We studied amniotic fluid specimens from 48 pregnancies. As expected, the major disaturated species of amniotic fluid phosphatidylcholine, dipalmitoylphosphatidylcholine, and palmitoylmyristoylphosphatidylcholine increased with gestational age, whereas phosphatidylcholine species with 34, 36, and 38 carbon atoms in the acyl radicals decreased. Although the amniotic fluid samples were obtained shortly before parturition (4.2 +/- 3.7 h, mean +/- SD), the correlation between dipalmitoylphosphatidylcholine concentration in amniotic fluid and gestational age was better than between dipalmitoylphosphatidylcholine concentration and the compliance of the respiratory system of the newborns. In addition, the percentage of amniotic fluid phosphatidylcholine species present as dipalmitoylphosphatidylcholine seemed to be a more reliable predictor of lung maturity than was the absolute dipalmitoylphosphatidylcholine concentration in amniotic fluid.

Amniotic Fluid↗
PubMed1980

[Pharmacologic influencing of fetal phospholipid synthesis. Part IV: influencing the DPL(dipalmitoyl-lecithin) content of fetal lung by betamethasone (author's transl)].

Dipalmitoyllecithinic (DPL) is the quantitatively largest and most active portion of the surfactant system. Hence only a quantitative DPL determination allows a relevant statement of fetal lung maturity. The antenatal prophylaxis of RDS should result in an increase of the DPL-level in a fetal lung. A new gaschromatographical method for determination of DPL was developed. The results were secured by gaschromatography-mass-spectrometry-couplings. After treatment with betamethasone an increase of the relative DPL-amount in fetal rat lung lecithin species was found, but not an increase of the lecithin-level in the lung-tissue. Corticosteroids probably induce transesterification of the lecithins.

Animals↗
PubMed1979

[Induction of fetal lung-maturity. Part III: surfactant-parameters in amniotic-fluid and fetal lung].

In animal experiments we determined surfactant-specific parameters of premature fetal lungs and of samples of amniotic fluid taken fromthe same animal, and compared them with each other. These parameters were, among others: total phospholipids, lecithine and palmitic acid. In these experiments, 75 gravid Wistar rats were treated with NaCl (controls) or drugs in clinically relevant doses for stimulating the fetal synthesis of phospholipids like betamethasone, bromhexine metabolite VIII and D-L-carnitine hydrochloride. A relation between the amniotic fluid and the fetal lung with regard to the quantity of surfactant substances was found - with a security of 95% - with the controls only. The value of amniotic fluid analysis is discussed under this aspect.

Amniotic Fluid↗
PubMed1978

Changes in essential fatty acids in plasma lipid fractions of polytraumatized patients with different parenteral nutrition.

We investigated changes in the fatty acid pattern of plasma lipids during the phase of total parenteral nutrition in two groups of polytraumatized patients. For parenteral nutrition we gave L-amino acid solutions in a dose of 0.24 g N day-1kg-1 body weight. In addition, we administered in the first group glucose and fructose, and in the second group glucose, fructose and fat emulsions in a total dose of 30 kcal day-1kg-1 body weight. In the latter group, the proportion of the fat emulsions was 30-40% of the calories administered. The most striking findings were the decrease of the essential fatty acids with regard to the phospholipid fraction from about 60% to 30% in the early post-traumatic phase. In the first group of patients we observed a further reduction of the essential fatty acids in the period of observation. This could be avoided by administering fat emulsions of the same type as we gave in the second group of patients. The functions of essential fatty acids in membranes and in the intermediary metabolism are discussed.

Dietary Fats↗
PubMed1978

[Pharmacologic influencing of fetal phospholipide synthesis. Part II: Carnitin - a new way of dyspnea syndrome prophylaxis? (author's transl)].

Carnitine is a body-owned Betaine which is wide-spread in living nature in the form of a physiologic metabolit. On account of its central metabolic function, Carnitine has various effects in the intermediary metabolism. Toxicity of Carnitine is very low. DL-Carnitine hydrochloride (30 mg/kg body weight) was injected into 25 gravid Wistar rats and 24 gravid rabbits, 4 days before the Cesarean section. Compared to the group of controls, the group treated with Bromhexine metabolit VIII, as well as to the group treated with Betamethason, significantly higher values with regard to the content of total phospholipids, lecithine and palmitic acid could be found in the fetal rat lungs. Effects of Carnitine on the phospholipid metabolism are discussed.

Ambroxol↗
PubMed1978

[Changes of the essential fatty acids in plasmalipid fractions of polytraumatized patients with different parenteral nutrition (author's transl)].

In two groups of polytraumatized patients we investigated changes in the fatty acid pattern of plasma-lipids during the phase of total parenteral nutrition. For parenteral nutrition we gave L-amino acid solutions in a dose of 0.24 g N/kg body weight/day. In addition, we administered in the first group glucose and fructose and in the second group glucose, fructose and fat emulsions in a total dose of 30 kcal/kg body weight/day. In the latter group, the proportion of the fat emulsions was 30-40% of the administered calories. We compared the achieved results with the values of a group of control persons. The most essential findings of these studies were the striking decrease of the essential fatty acids with regard to the phospholipid fraction in the early post-traumatic phase. In the first group we observed a further reduction of essential fatty acids during the period of observation. This could be avoided by administering fat emulsions of the same type as we gave in the case of the second group of patients. The functions of essential fatty acids in membranes and in intermediary metabolism are discussed.

Amino Acids↗
PubMed1978

[Pharmacologic influencing of fetal phospholipide synthesis. Part I: Effect of betamethasone and bromohexine metabolit VIII (Ambroxol) (author's transl)].

The effect of Betamethasone and Bromhexine-Metabolite VIII, commonly used in RDS-prevention, was studied in pregnant rats and rabbits. 73 rats and 78 rabbits were treated for 4 days with doses, similar to those used in men. Cesarean section was performed in rats from the 18th-21th day of gestation (23 days), in rabbits from 27th-30th day (32 days). In the amniotic fluid, in fetal and maternal lungs the total phospholipid content, percentage of lecithins in total phospholipids and palmitic acid were determined and used as parameters for the surfactant content. There was no sign of induction with regard to synthesis. Premature deliveries and malformed fetusses were frequently observed under steroid-therapy. Clinical application should therefore be observed more critically.

Ambroxol↗
PubMed1976

[Surfactants in amniotic fluids: a comparision between biomechanical and biochemical analyses (author's transl)].

44 specimens of amniotic fluid from the 25 week's gestation onwards were tested in a modified Wilhelmy-Langmuir surface balance. In addition percentage of lecithin in total phospholipids, total phospholipd phosphorus concentration and fatty acid composition of lecithin was determined. Lecithin, total phospholipid-phosphorus and palmitic acid show significant rises in concentration with gestational progress. The results of the surface tension measurements are significantly correlated with the biochemical analysis. Therefore, fetal lung maturity seems to be well estimated by the biomechanical method.

Amniotic Fluid↗