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Biomedical subjects

V Lehmann

Publications and source records attributed to V Lehmann.

At least 91 records · Page 5Linked to original sources
PubMed1977

Isolation, purification and properties of an intermediate in 3-deoxy-D-manno-octulosonic acid--lipid A biosynthesis.

Incomplete lipid A has been purified from a mutant of Salmonella typhimurium which is temperature-sensitive both in synthesis of 3-deoxy-D-manno-octulosonic acid 8-phosphate (dOclA-8-P) and in growth. Pulse-chase experiments have shown that the incomplete lipid A molecule is the intermediate in the biosynthesis of the dOclA-lipid A portion of lipopolysaccharides. The purification procedure included DEAE-cellulose chromatography and electrodialysis. A highly water-soluble precursor material was obtained, consisting of glucosamine, phosphate and 3-hydroxymyristic acid in a molar ratio of 1:1.2:2.1. Labeling experiments as well as chemical degradation procedures revealed the precursor molecule to be composed of a diphosphorylated glucosamine-disaccharide carrying two amide-linked and two ester-linked 3-hydroxymyristic acids. In contrast to the complete dOclA-lipid A part, the intermediate lacks 3-deoxy-D-manno-octulosonic acid as well as nonhydroxylated fatty acids. On the basis of these findings a pathway for the final steps in dOclA-lipid A biosynthesis is proposed.

Acetylglucosamine↗
PubMed1977

Endocarditis caused by Pasteurella multocida.

A 51-year-old previously healthy man developed endocarditis with low grade fever, aortic insufficiently and multiple arterial emboli. An atypical strain of Pasteurella multocida was isolated from each of 3 consecutive blood cultures. Protracted treatment with high doses of penicillin G was necessary to eradicate the infection. Following resection of the damaged aortic valves and implantation of a valve prosthesis, the patient recovered. P. multocida should be regarded as one of the possible causes of subacute bacterial endocarditis.

Aortic Valve↗
PubMed1977

[External version from breech to vertex presentation (author's transl)].

An analysis of 51 attempts at version was made of which 27 were successful (53%). In 3 cases an emergency cesarean section had to be performed following the attempt at version. In 2 of these cases there was partial premature detachment of the placenta. Attempts at version were begun in the 36th week of pregnancy. Up to the 38th week there was a 67% success rate, while from the 39th week onward it was only 41%. In cases of parity it can be shown clearly that the success rate increases with parity. When the pregnancy is the mother's first, 58% of attempts fail, while in fourth pregnancies this figure is only 25%. Attempts at version are most successful when the placenta is attached to the posterior uterine wall. The size and weight of the fetus do not affect success. The average weight of the placenta in the success group is significantly higher (by about 60 g) than in the failure group. There were no significant differences between the two groups as regards the dimensions of the mother's pelvis. In about 30% of cases there was a fetomaternal transfusion. The frequency of erythrocyte transfer is dependent on the force of manipulation used in the attempt at version and on the position of the placenta. The frequency of section is significantly lower (14%) in the success group than in the failure group (43%). Diagnoses of the newborn's condition (pH value and Apgar score) did not reveal any decisive differences between the two groups. In view of the high rate of complications and failures external version from breech to vertex presentation cannot be recommended.

Apgar Score↗
PubMed1977

[The effect of Partusisten on the maternal and fetal metabolism, acid-base balance and blood gases intrapartum (author's transl)].

Following i.v. injection of 50 g of Partusisten into the mother there occurs, already within 5 min., a rise in the lactate concentration which reaches its peak after 25--30 min. After 25 min, a similar can be shown in the fetus. The fetal pO2 at this time has risen significantly to 2.1 mmHg, while the pCO2 has fallen by 3 mmHg. The increase in lactate concentration both in mother and fetus alters the acid base balance in both. pH is reduced and base deficit is raised, parallel in mother and fetus. The fetal acidosis is probably due to a lactate infusion from the mother.

Acid-Base Equilibrium↗
PubMed1976

[Indications and results of cerclage in cervical incompetence (author's transl)].

The results of 79 cerclage operations in gestation are reported. The rate of abortion increased in cases of more severe symptomatics: firstly, without labour and bleeding: 83 p.c. successful operations; secondly, with labour: 77 p.c.; thirdly, bleeding and without labour: 70p.c.; and lastly, with labour and bleeding: 40p.c. Before treatment with tocolytic pharmaca was possible, the period of gestation time could not successfully be prolonged if labour had started. With tocolytic pharmaca 56p.c. patients of this group gave birth to a living child. The rate of premature children was 23p.c. Cerclage operations were most successful after the 25th week of gestation. When applied before the 16th week of gestation, the success rate was below 69p.c. Treatment with tocolytic pharmaca increased the indication for cerclage operations. Cerclage operations together with tocolytic treatment are indicated in cases where labour and bleeding occur in gestation.

Female↗
PubMed1976

[Study of resistance to physical stress in pregnant women: influence of standardized work on cardiovascular system, ventilation, gaseous interchange, carbohydrate metabolism and acid-base balance (author's transl)].

10 women in the 12th week of pregnancy were tested with 50 and 60 watts on the bicycle ergometer; 16, in the 38th week of pregnancy and 12 weeks after delivery. Heart rate, blood pressure, O2 intake, CO2 elimination, respiration rate, respiratory volume per minute, lactate, pyruvate, glucose, pCO2, base excess and pH were measured at rest and under stress. Already in the 12th week of pregnancy (SSW), O2 intake and calorie consumption for the same work was significantly higher than in the nonpregnant subjects. Heart rate and blood pressure behaved the same during and outside of pregnancy. In the 38th week of pregnancy, the steady-state was reached later. O2 intake and calorie consumption were significantly increased. In pregnant women, the glucose level decreased about 11 mg% under stress while it remained constant in nonpregnant subjects. In pregnant women, lactate production is significantly higher (26%) during work. Metabolic acidosis cannot be compensated by respiration. The base deficit was significantly larger; pH was reduced. In pregnant women, physical stress produces increased respiration, CO2 consumption and calorie consumption are increased, CO2 deficit is greater and metabolic acidosis develops.

Acid-Base Equilibrium↗