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Biomedical subjects

I Richter

Publications and source records attributed to I Richter.

At least 55 records · Page 3Linked to original sources

Competing pathways in the formation of alkyl, alk-1-enyl and acyl moieties in the lipids of mammalian tissues.

The distribution of radioactivity from intravenously administered cis-9[1-14C]octadecenol into various tissues of the rat was studied as a function of time. The pattern of incorporation of radioactivity into alkyl, alk-1-enyl and acyl moieties of the lipids in heart, lungs, liver, intestine, kidney, brain and plasma revealed that oxidation of the long-chain alcohol and esterification of the resulting fatty acid to a wide variety of lipids are by far the most predominant reactions. Acylation of the long-chain alcohol is observed especially in liver, which appears to be the major site of biosynthesis of wax esters. Alkylation of the long-chain alcohol to alkoxylipids occurs in most tissues, most predominantly in the heart.

Acylation↗

Pharmacokinetics of azlocillin in neonates.

The pharmacokinetics of the acylureido-penicillin, azlocillin, were studied after intravenous or intramuscular injections in 53 premature and full-term infants with infections. Effective concentrations wer" achieved in premature babies after doses of 50 mg/kg every 12 h and in full-term infants with 100 mg/kg every 12 h. No untoward effects of azlocillin were observed. On the basis of these studies, a dosage schedule for azlocillin has been established.

Azlocillin↗

Amoxicillin in paediatrics, with special reference to its excretion into bronchial secretion.

Pharmacokinetic examinations with amoxicillin in neonates and prematures are reported. Good values of up to 5 mcg/ml after 24 hours were achieved with two doses of 50 mg/kg amoxicillin daily. Amoxicillin was also found in the meconium, although quantities varied greatly. Amoxicillin is recommended for the treatment of disorders of the respiratory tract because of its good absorption, tissue penetration and tolerance. Examinations to assess the excretion of amoxicillin into the bronchial secretion were therefore carried out in 88 children in different age groups. Two artificial respiration bronchoscopies were carried out with an interval of 7 days, and the bronchial secretion collected and tested for organisms and for amoxicillin concentrations. After the first bronchoscopy, patients were given amoxicillin for 7 days, in doses of 125 to 750 mg t.i.d., corresponding to 40-100 mg/kg body weight. Some very high amoxicillin values were found, especially in those groups from whom the secretion was taken 2, 3, or 4 hours after the last amoxicillin treatment. The values were widely scattered. We recommended 50-100 mg/kg for broncho-pulmonary diseases.

Absorption↗

Computed tomographic findings in intracranial meningioma.

The computed tomographic findings in 54 patients with intracranial meningioma are presented. Computed tomography is a rapid, noninvasive and highly accurate method of diagnosing intracranial meningioma and, in most cases, the findings are specific for this tumor.

Adolescent↗

[Experience with sisomicin in pediatrics (author's transl)].

Sisomicin, an aminoglycoside antibiotic, is especially effective against Escherichia coli, Klebsiella, Enterobacter, Citrobacter, Serratia, indole-positive and indole-negative Proteus species, Pseudomonas aeruginosa, Salmonella and Staphylococcus aureus. It has a bactericidal action. Although sisomicin is similar to the other aminoglycoside antibiotics, there is not complete cross-resistance to them. Our own pharmacokinetic investigations showed that a dose of 2--3 mg/kg body weight of sisomicin twice daily is necessary in the neonatal period. Infants should be given 2.5 mg/kg body weight three times daily, and school children 1.5--20 mg/kg body weight, likewise three times daily. Excretion of sisomicin in the urine is lower in children than in adults, amounting within 24 hours to only 10--20% in newborns, and 30--40% in school-children. Sisomicin induces excretion of some enzymes in higher quantities from the tubular part of the kidneys, especially alaninaminopeptidase. A report is given on 58 patients, especially newborns and prematures, who were treated for about seven days with sisomicin. The results obtained with a wide variety of infections (such as omphalitis, aspiration of amniotic fluid with broncho-pneumonia, phlegmons of the galea, and also pyelonephritis and mucoviscidosis with pulmonary complications) can be described as good, with a success rate of 85%. On only seven occasions were insignificant transitory side-effects, such as slight increase in transaminases, toxic-allergic exanthema and pain in the region in injection, observed.

Age Factors↗

[Pediatric pharmacology of azlocilin (author's transl)].

Pharmacokinetic investigations of acylureido-penicillins azlocillin in newborns, infants and school shildren showed age dependend results. The differences were especially evident in a prolongation of the serum half-life to 2,56 hours in newborns compared to 0.94 hours in school children. On the basis of our pharmacokinetic results and of the dosages resulting from the data the antibiotic was used clinically in twenty eight patients with Pseudomonas aeruginosa infections and one patient with a Proteus mirabilis infection. The results were much better in infections of the urinary tract than in infections of the respiratory tract. This might be due to an observe bacterial presistence in spite of highly effective levels of azlocillin in bronchial secretion. The tolerance to the antibiotic was good.

Child↗

[On the excretion of azlocillin with bronchial secretion in children (author's transl)].

This pharmacokinetic study involved school children who were treated with 6-[(R)-2-(2-oxo-imidazolidine-1-carboxamido)-2-phenyl-acetamido]-penicillanic acid sodium walt (azlocillin, Securopen) at doses of 50 mg/kg bodyweight or 75 mg/kg body weight i.v. Kinetics of the first order were found for the concentrations measured at the same time, being proportionate to the administered dose, while there was no dose dependence for the relative distribution volume. The elimination half-life was about 55 min. In 25 children of different age who had to undergo bronchoscopy for diagnositic and therapeutic reasons, the azlocillin concentrations in the bronchial secretions were measured 1 h and 4 h after the administration of 75 mg/kg quantity of bronchial secretion was obtained, azlocillin concentrations of 30 - 240 microgram/g were found. Measurements of azlocillin concentration in the bronchial secretion and in the serum, which were made at the same time, did not show any correlation.

Adolescent↗

Experience with amoxycillin in neonates and premature babies.

Amoxycillin, a semi-synthetic penicillin, resembles ampicillin in many respects. There is cross-resistance between the two antibiotics. Numerous Gram-positive and Gram-negative organisms are sensitive to amoxycillin at relatively low dosage. Investigations using oral amoxycillin, 50 mg/kg body weight were carried out in neonates and premature babies in the first days of life. Peak values of 38 microng/ml and 59 microng/ml at 4 1/4 hours were obtained for the neonates and premature babies respectively. The 10-hour value for the first group was 13 microng/ml and for the second 19 microng/ml. With a single dose of amoxycillin, serum levels of 0.9 microng/ml were still obtained after 24 hours. In children who received the same dose twice daily, the serum values were 6.5 microng/ml after 24 hours. The urinary excretion of amoxycillin was, on an average, 41% in 24 hours. Amoxycillin was also found in the meconoium, but the quantity in the different portions showed a large dispersion. Amoxycillin can, therefore, be recommended as an effective and well tolerated antibiotic for use in the neonatal and premature period. In general the drug should be administered 12-hourly at a dose of 50 mg/kg body weight. Only in severe illnesses is 8-hourly administration required.

Amoxicillin↗

[Amoxicillin and its excretion into bronchial secretion (author's transl)].

Various dates on amoxicillin (resorption, distribution, elimination, tissue passage, urinary excretion) are presented. The bacterial spectrum is more fully discussed. Amoxicillin is compared with ampicillin. Dosage and therapeutical results are presented. Within repeated bronchoscopic examinations necessary on account of bronchopulmonary affections determination of germs were done in 88 children. At the same time examination of ampicillin levels in bronchial secretions were performed after amoxicillin therapy with different high doses (3 x 125 mg to 3 x 750 mg) for 7 days. It could be shown that good antibiotic levels could be found in secretion specimens above all obtained 2 to 4 hours after the last amoxicillin administration. They could be found too, if there did not exist any purulent secretion or stronger inflammation. There are relations between the amount of dosage, the level in secretion as well as the influence on germs.

Adolescent↗

Long-chain (Z)-9-alkenes are "psychedelics" to houseflies with regard to visually stimulated sex attraction and aggregation.

Three different tests on houseflies (Musca domestica L.) revealed that both pheromone-free pseudoflies and male partner flies exhibit in the presence of mixtures of long-chain (Z)-9-alkenes or pure (Z)-9-tricosene enhanced releasing effects for two optical cues, which stimulate male houseflies to mating strikes and houseflies of both sexes to aggregation.

Alkenes↗

[Allergic reactions to the house-dust mite in children with obstructive disease of the respiratory tract (author's transl)].

160 children with obstructive allergic disease of the respiratory tract were tested with the modified pricktest. 58 showed positive reactions to the house-dust mite. Typically, in the case history of these children, is the presence of the complaints throughout the year, especially at night and not in particular seasons. Although, the modified pricktest could be negative in children under 4 years of age, in later years an allergen could be found. Children who have typical-complaints in their case-history, but show weak cutaneous reactions, are admitted in hospital, and a bronchial provocationtest is carried out to study the action of the allergen on the affected organ. 28 of the 58 children with house-dust mite allergy showed only weak positive cutaneous reactions and had mild complaints. Avoidance measurements brought in almost 80 p.c. of these cases good results. We recommended specific hyposensibilisation for the remaining 30 patients; in 22 of these cases the recommendation was carried out. The positive effect of the specific hyposensibilisation was proved when compared to a controll series.

Age Factors↗