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Biomedical subjects

B Roth

Publications and source records attributed to B Roth.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Responders and non-responders of surfactant therapy of very small premature infants. A clinical, histopathologic and immunohistochemical analysis].

The administration of surfactants is highly effective and yields an immediate clinical response in cases of a lack of surfactant in the premature lung of preterm infants. The administration of surfactants might diminish the need for intensive care and artificial ventilation thereby also reducing or preventing the severe side effects associated with these therapeutic measures. However, the lack of clear clinical features precludes a reliable predictive forecast of the therapeutic outcome. Only the therapeutic follow-up period can disclose possible damage due to the administration of surfactants. Histological preparations of lung specimens from non-responding infants reveal cellular inflammatory infiltrations, destruction of the alveolo-capillary basement membrane and monocytic phagocytosis.

Antibodies, Heterophile↗
PubMed1991

[Ureaplasma urealyticum--a new problem pathogen in neonatology].

Some previous studies showed that Ureaplasma urealyticum is the most common germ that appears in the birthway of pregnant women and which is also frequently found in skin swabs and secretions of newborn and premature babies. The colonization of pregnant women by Ureaplasma urealyticum makes a premature birth more likely. Another factor of risk for a premature infant is a premature rupture of membranes for more than 24 hours which also makes an infection possible. There exists an association between pulmonary infection by Ureaplasma urealyticum and the development of a bronchopulmonary dysplasia especially for premature babies. According to our observations acute exacerbations of severe pneumonia can appear even after month. An attempt of therapy of pulmonary infection should be undertaken with erythromycin, if sensitive serotypes are present. In the case of erythromycin resistance chloramphenicol can be used but only under frequent controls of blood levels. We were able to observe rapid improvements with this effective therapy.

Anti-Bacterial Agents↗
PubMed1990

Phospholipid specificity of bovine heart bc1 complex.

Bovine heart bc1 complex was reversibly inactivated by a new simple and effective chromatographic delipidation method. Upon phospholipid replenishment, catalytic activity increased from values near zero to values 2-6-times higher than those of the original preparation. Compared to original preparations maximally activated by additional phospholipid, the degree of reactivation was up to 100%. By this delipidation method, the 6.4-kDa protein subunit was removed with the phospholipid. The loss of this protein neither diminished electron transport activity nor abolished proton translocation. Two requirements were necessary to obtain quantitative data: (a) only bc1 complexes, homogeneously dissolved before and after relipidation had to be used and (b) the phospholipid bound to the complex had to be determined. The correlation of catalytic activity to bound phospholipid was studied in the range of low phospholipid/protein ratios, which had previously been insufficiently resolved. Catalytic activity increased linearly with added phospholipid up to a molar ratio of 80-100 lipid molecules/dimeric complex. This corresponds to the number of phospholipid molecules that complete a single bilayer annulus. The activating effect of phospholipid is not merely due to a hydrophobic phase effect, since it strongly depends on the nature of the polar head group of the added phospholipid. Of the three major phospholipids bound to the bc1 complex, only phosphatidylethanolamine and phosphatidylcholine activated when added as sole phospholipid. Tightly bound diphosphatidylglycerol was needed for preservation of the native complex structure.

Animals↗
PubMed1990

[Hypersomnia with sleep apnea. I].

The author gives an account of present knowledge on the syndrome of hypersomnia with sleep apnea (HSA). After a historical introduction he deals with the incidence of this syndrome in Czechoslovakia; there are few accounts of this syndrome in the Czech literature. The author holds the view that this affection which is very frequent in other countries frequently escapes diagnosis in this country because the patients are not examined by sleep polygraphy which is essential for the diagnosis of HSA. The author describes also individual symptoms of the affection, i.e. hypersomnia, impaired respiration during sleep with frequent apnoic intervals, obesity, cardiovascular disorders and psychic changes. He emphasizes also the frequent incidence of tissue hyperplasia in the oropharyngeal area which leads to stenosis in this area.

Humans↗
PubMed1990

[Hypersomnia with sleep apnea. II].

In the submitted paper the author gives an account of different affection associated with the syndrome of hypersomnia with sleep apnea. They include diseases and malformations with stenosis of the upper airways in the oropharyngeal area, particularly marked during sleep. They comprise also affections of nervous structures which innervate muscles in this area. The author pays attention to the frequent incidence of this syndrome in children with hypertrophic tonsils and adenoid vegetations. In this connection he mentions the cot death syndrome where very often death occurs during the apnoic interval as a result of immaturity of nervous structures which regulate respiration during sleep. The author describes also pathophysiological mechanisms of development of HSA and the diagnosis of this affection where examination by sleep polygraphy is essential. In the subsequent part of the work the author reviews contemporary conservative and surgical treatment of HSA.

Child↗
PubMed1990

[Pregnancy outcome with intensified insulin therapy in manifest diabetes].

In 1981, the intensified insulin therapy for achievement of euglycaemia in pregnant diabetics was introduced at the University Department of Obstetrics and Gynaecology in Cologne. This study compares the results of 112 pregnancies in women with overt diabetes monitored before (1971-1980) or after (1981-1988) changing the therapeutic regimen. In the period from 1981 to 1988, the proportion of euglycaemic patients (preconceptionally 19%, before delivery 79%) was clearly higher than from 1971 to 1980 (n = 42; 7% and 9%, respectively). The tight blood glucose control resulted in a doubling of hypoglycaemic episodes during pregnancy. The proportion of preterm deliveries was reduced from 47% to 24%. The rate of caesarean sections was nearly constant (1971-1980: 38%, 1981-1988: 34%). The marked success of therapy was the decrease of perinatal mortality from 20.9% to 2.9%. The perinatal morbidity also diminished, as shown by the decreasing rates (30-90%) of foetopathy, macrosomy, respiratory distress syndrome, birth trauma, hypoglycaemia, hypocalcaemia and polycythaemia. The malformation rate, however, remained high (1971-1980 = 7%, 1981-1988 = 11%). The results demonstrate the necessity of a strict blood glucose control during pregnancy, beginning before the time of conception.

Adult↗
PubMed1990

Effects of kallikrein on sperm motility, capillary tube test, and pregnancy rate in an AIH program.

From 1984 to 1986, 172 couples were enrolled in an artificial insemination homologous (AIH) program, because of negative postcoital test, fair PT, positive PT with unexplained infertility, and impotentia coeundi. Patients were randomly assigned to the following procedures: AIH with native semen (N, n = 68), washed sperm (V, n = 50), semen mixed with kallikrein (K, 5 IE/ml semen, n = 45), and timed intercourse. The overall pregnancy rate (PR) was 22% per couple (13% inseminations, 9% spontaneous). PR from insemination (spontaneous) was 13% (8), 13% (13), 23% (0) in PT negative, fair, and positive patients, respectively, and 18% (9), 13% (7), and 11% (9) in AIH groups N, V, and K. Among in vitro studies with K added semen, an improvement of sperm motility was demonstrated in half of the specimens. In the capillary tube test (CTT), with wives' cervical mucus, a deterioration was more frequently seen than an improvement after 2 h, independent of the early effect of K in semen, K induced changes of CTT were less pronounced when donors' cervical mucus was used. The results of the in vitro studies offer an explanation for the low PR in the AIH program with K.

Adult↗
PubMed1990

[The status of computerized tomography and conventional tomography in the assessment of endobronchial growth and extension of central bronchial cancer].

In comparison with endoscopy, computed tomography can produce excellent results with respect to the endobronchial spread of central bronchial carcinomas. Used for the same purpose, conventional tomography of the central bronchial system is greatly inferior. With respect to an evaluation of the endobronchial tumour growth configuration, computed tomography of the chest showed agreement with the endoscopic findings in only 56 per cent of all cases. This would seem to indicate that for the planning of palliative bronchological measures, such as, for example, laser therapy and afterloading treatment, prior endoscopic inspection is indispensable. By themselves, the results obtained with the imaging procedures described in this article are not adequate.

Bronchi↗
PubMed1989

[Urinary bioavailability of sodium-2-mercaptoethanesulfonate (Uromitexan) following intravenous, subcutaneous and continuous subcutaneous administration].

The dose-limiting urotoxicity of the oxazaphosphorines (t1/2 = 4-15 h) is due to renal elimination of metabolites such as acrolein. The occurrence of hemorrhagic cystitis can be safely prevented by the concomitant use of i.v. or oral 2-mercaptoethanesulfonate sodium (DCI MESNA; Uromitexane). The bioavailability of oral MESNA is in the range of 20-50% and its unpleasant taste severely limits patient compliance. Due to the short half-life of MESNA (approx. 40 min) a regular fractionated or continuous administration is mandatory. In 6 healthy volunteers we have studied the pharmacokinetics of urinary MESNA elimination for the assessment of MESNA bioavailability after i.v. and s.c. drug administration. MESNA was given at doses of 400 mg for i.v. and s.c. bolus injections and 800 mg for continuous s.c. administration by a portable infusion pump. For the s.c. route an isotonic solution was prepared. The total amount of urinary thiols was assessed by the Ellman method (photometric reading at 412 nm). Total elimination of i.v. MESNA was 83.2 +/- 3.4% of the dose administered. The respective results for s.c. bolus and s.c. continuous drug administration were 81.9 +/- 3.4% and 79.4 +/- 3.6% of the dose. Continuous administration theoretically will provide optimal uroprotection from short term (hemorrhagic cystitis) and long term (bladder fibrosis and cancer) toxicity.

Biological Availability↗
PubMed1989

Tracheal agenesis: a case report.

Tracheal agenesis is described in a premature infant. Absent cry, failure of tracheal intubation despite adequate ventilation with a face mask, and ventilation of both lungs after oesophageal intubation suggested the diagnosis. The infant's condition deteriorated rapidly because of severe pulmonary hyaline membrane disease 12 h later due to intractable cardiac failure. At post-mortem examination, large bilateral broncho-oesophageal fistulae were found.

Congenital Abnormalities↗
PubMed1989

2,4-Diamino-5-benzylpyrimidines and analogues as antibacterial agents. 10. 2,4-Diamino-5-(6-quinolylmethyl)- and -[(tetrahydro-6-quinolyl)methyl]pyrimidine derivatives. Further specificity studies.

A series of 18 2,4-diamino-5-[(1,2,3,4-tetrahydro-6-quinolyl)methyl]pyrimidines has been prepared by the condensation of 2,4-diamino-5-(hydroxymethyl)pyrimidine with 1,2,3,4-tetrahydroquinolines in acidic medium. Several derivatives were catalytically aromatized; others were synthesized from these by routine aromatic substitution or by condensations of (anilinomethyl)pyrimidines to give quinolinylmethyl analogues. Compounds with 4-methyl-8-methoxy substitution are closely related to trimethoprim (1a) in structure and are excellent inhibitors of bacterial dihydrofolate reductase, with activity at least equivalent to that of 1a. The highest degree of inhibition was achieved with the rigid aromatic series, but greater specificity was accomplished among the tetrahydroquinoline derivatives. This was directly related to N-1 substitution of 4-methyl-8-methoxy derivatives. The spatial relationships around N-1 and protonation at this site may both affect selectivity. Such compounds also had excellent broad-spectrum in vitro antibacterial activity.

Animals↗
PubMed1989

2,4-Diamino-5-benzylpyrimidines and analogues as antibacterial agents. 11. Quinolylmethyl analogues with basic substituents conveying specificity.

A series of nine 2,4-diamino-5-[6-( or 7-)quinolylmethyl]pyrimidines has been prepared by condensations of quinolinecarboxaldehydes with beta-anilinopropionitriles, followed by treatment with guanidine. All compounds has basic or methoxy substituents at the 2- or 4-positions of the quinoline ring. All of the 6-quinolylmethyl derivatives were highly inhibitory against Escherichia coli dihydrofolate reductase (DHFR), provided that an 8-substituent was present in the quinoline ring. Those compounds that had basic substituents in the 2-position of the quinoline ring were also highly specific for bacterial dihydrofolate DHFR, relative to a vertebrate counterpart. Protonation on the quinoline ring nitrogen is a possible cause of specificity.

Animals↗
PubMed1989

2,4-Diamino-5-benzylpyrimidines and analogues as antibacterial agents. 12. 1,2-Dihydroquinolylmethyl analogues with high activity and specificity for bacterial dihydrofolate reductase.

Twelve 2,4-diamino-5-[(1,2-dihydro-6-quinolyl)methyl]pyrimidines containing gem-dimethyl or fluoromethyl substituents at the 2-position of the dihydroquinoline ring were prepared by condensations of dihydroquinolines with 2,4-diamino-5-(hydroxymethyl)pyrimidine. The dihydroquinolines were produced from the reaction of anilines with mesityl oxide or fluoroacetone. In some cases, 1-aryl-2,4-dimethylpyrroles were obtained as byproducts. Most of these pyrimidines were highly inhibitory to Escherichia coli dihydrofolate reductase (DHFR) and also had high specificity for the bacterial enzyme. 2,4-Diamino-5-[[1,2-dihydro-2,4-dimethyl-3-fluoro-2-(fluoromethyl)-8- methoxy-6(1H)quinolyl]methyl]pyrimidine had an apparent Ki value for E. coli DHFR 13 times lower than that of the control, trimethoprim (1), and was 1 order of magnitude more selective for the bacterial enzyme. It had outstanding activity against Gram-positive organisms in vitro, as well as broad-spectrum antibacterial activity equivalent to that of 1. The results of in vivo testing will be reported elsewhere. The gem-dimethyl substituents of the dihydroquinoline derivatives are considered to be responsible for the high selectivity, as well as contributing to potent bacterial DHFR inhibition. Molecular models are presented which suggest the probable interactions with the bacterial enzyme.

Animals↗
PubMed1989

2,4-Diamino-5-benzylpyrimidines as antibacterial agents. 13. Some alkenyl derivatives with high in vitro activity against anaerobic organisms.

A series of 2,4-diamino-5-(3,5-dialkenyl-4-methoxy- or -4-hydroxybenzyl)pyrimidines was prepared from [(allyloxy)benzyl]pyrimidines by Claisen rearrangements, and the resulting allyl phenols were further modified by methylation and rearrangement to 1-propenyl analogues. Analogous 3,4-dimethoxy-5-alkenyl derivatives were prepared by similar techniques. High in vitro antibacterial activity was obtained against certain anaerobic organisms, such as Bacteroides species and Fusobacterium, which was equal to or better than the control, metronidazole, in several cases. The profile was similar against Neisseria gonorrhoeae and Staphylococcus aureus. The 3,5-bis(1-propenyl)-4-methoxy derivative 8 was 1 order of magnitude more active against Escherichia coli dihydrofolate reductase than its saturated counterpart, and it was also more active than trimethoprim, 1. However, it was considerably less active in vitro against the Gram-negative organisms. The 3,4-dimethoxy-5-alkenyl, -5-alkyl, and -5-alkoxy analogues had very high broad-spectrum antibacterial activity. However, pharmacokinetic studies of four of the compounds in dogs and rats and in vivo studies with an abdominal sepsis model in rats showed no advantages over trimethoprim.

Alkenes↗