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Biomedical subjects

G Schramm

Publications and source records attributed to G Schramm.

At least 19 recordsLinked to original sources
PubMed1990

The influence of nutritional factors on biopterin excretion in laboratory animals.

Nutritional influences on urinary total biopterin levels in rats and pigs were investigated. During the first nights in metabolic cages with food deprivation a significant increase in biopterin values was found in rats. This could be diminished either by feeding, adaptation to food deprivation or by oral glucose application. With food deprivation under normal housing conditions, this increase could not be found. Rats that were fed a cellulose preparation without metabolizable energy had no increase in biopterin excretion. The circadian rhythm of biopterin excretion was influenced by food deprivation as well as by cellulose. Alterations in water intake and urinary output had no effect on biopterin levels related to creatinine. Remarkable changes in biopterin excretion are more likely due to hormonal functions and regulations related to stress than to nutritional factors. More investigations into these problems are being performed.

Animal Nutritional Physiological Phenomena↗
PubMed1986

Local exchange of oxytocin from the ovarian vein to ovarian arteries in sheep.

Local transfer of 125I-labeled oxytocin from the ovarian vein to arteries supplying the ovary, the oviduct, and the tip of the uterine born has been investigated. In five sheep, 10 infusions of 125I-oxytocin over a period of 1 h were performed, and the concentration of labeled polypeptide in the peripheral plasma was compared to ovarian arterial plasma. During 2 consecutive infusions into each animal's ovarian vein, blood was collected simultaneously from the following sites: ovarian branch of the ovarian artery (OBOA), tubal branch of the ovarian artery (TBOA), uterine branch of the ovarian artery (UBOA), and from the jugular vein. In all experiments the concentration of 125I-oxytocin in ovarian arterial plasma was higher than in peripheral plasma. The ratio of ovarian artery/jugular vein for 125I-oxytocin was: OBOA 2.8, TBOA 1.8, UBOA 1.6. Based on a 4 ml/min blood flow through ovarian arteries supplying ovary, oviduct, and the tip of the uterine horn, the local transfer of the total amount of oxytocin infused was estimated to be about 1% (range: 0.1-4.4%). Analysis of variance did not reveal significant differences in the exchange ratios between OBOA, TBOA, and OBOA. However, the variances within these groups are significant, presumably because of anatomical variation in the degree of surface contact area between arteries and veins at the ovarian pedicle. It is concluded that polypeptides are locally recirculated to ovaries, oviduct, and the tip of the uterine horn in a higher concentration than is supplied by peripheral blood. This could provide a mechanism for local distribution and concentration of the ovarian peptides that regulate reproductive function.

Animals↗
PubMed1986

Direct venous-arterial transfer of 125I-radiolabelled relaxin and tyrosine in the ovarian pedicle in sheep.

125I-labelled relaxin and tyrosine were infused into the ovarian vein to investigate transfer to branches of the ovarian artery at the ovarian pedicle in sheep. The ovarian arteries supply the ovary, the oviduct, and the tip of the uterine horn. An exchange of relaxin (n = 24) and tyrosine (n = 18) was observed in blood samples collected from all branches of ovarian arteries. This is expressed as a ratio of radioactivity greater than 1 between jugular venous blood plasma and arterial blood plasma. The average ratio (+/- s.d.) over the total infusion period of 1 h was 1.42 (+/- 0.35) for relaxin and 1.69 (+/- 0.38) for tyrosine with maximal values up to 4.9 and 2.9, respectively. Of the total amount of substance infused (348 pmol/h), 0.22% of the relaxin and 1.19% of the tyrosine reached the adjacent arteries directly. From these investigations it is concluded that molecules with a molecular weight of approximately 6000 can be transferred directly from veins to arteries at the ovarian pedicle, and the efficiency of this exchange does not only depend on molecular size.

Animals↗
PubMed1983

Corpus luteum regression induced by ultra-low pulses of prostaglandin F2 alpha.

In view of the pulsatile nature of PGF2 alpha secretion from the ovine uterus at the time of luteolysis, experiments were designed to examine the effect of pulsed infusions of PGF2 alpha on luteal function and to re-examine the minimal effective levels of PGF2 alpha required to induce luteolysis. To mimic physiological conditions, hour-long infusions of PGF2 alpha in increasing concentrations were given either 4 times in 19 h or 5 times in 25 h into the arterial supply of the autotransplanted ovary in conscious sheep on day 12 of an induced cycle. Blood flow and progesterone secretion rate from the ovary were used to monitor directly the luteolytic effect of administered PGF2 alpha. The concentration of LH in peripheral plasma was measured throughout each infusion experiment and the presence of a preovulatory peak of LH was used as an indicator of the permanence of luteal regression. Four pulses of PGF2 alpha in 19 h caused complete corpus luteum regression in only 1 of 4 animals whereas the addition of a fifth pulse (5 pulses in 25 h) caused permanent regression in 4 out of 4 animals. Infusion of 5 hour-long pulses of saline or PGF2 alpha at a rate less than 0.04 microgram/h did not induce permanent suppression of progesterone secretion. The average total effective dose of PGF2 alpha required to induce luteal regression when given as 5 pulses was 1/40th of the amount currently regarded as the minimal effective one when given by constant infusion into the ovarian artery. In another series of experiments the luteolytic effect of a single hour-long pulse of 0.1 microgram/h PGF2 alpha given daily for either 3 or 4 days was investigated. A significant fall (ANOVA, F0.01) in progesterone secretion rate, which reached a nadir at 5.3 +/- 2.2 h (means +/- S.D., n = 15), was followed by a recovery of progesterone secretion rate. Permanent luteal regression did not occur with this protracted regimen, suggesting that a relatively short pulse frequency of PGF2 alpha over a minimal period of 24 h is a necessary condition for physiological regression of the corpus luteum in sheep.

Animals↗
PubMed1983

[Congenital aneurysms of the left atrium with intact pericardium--value of diagnostic methods for recognition, prognosis and therapy].

An intrapericardial aneurysm of the left atrial appendage in a 7-year-old girl is reported. Review of the 36 cases described up to now reveals that there is no specific age for this disease. It is therefore questioned whether this defect is really congenital in origin. Systemic embolism and serious rhythm disturbances are the most common complications; the younger the patient, the less likely they are to occur. Systemic embolism has only been described in the case of aneurysms located at the left atrial appendage, not in aneurysms of other parts of the left atrial wall. The risk of the development of rhythm disorders, however, is independent of the location within the left atrium. Clinical findings (including ECG) are nonspecific. Cardiomegaly and unusual configuration of the heart are constantly found, but are not pathognomonic. The diagnosis is usually confirmed by angiocardiography. Operation seems always to be indicated if complications are to be avoided. Operative deaths or complications during the follow-up after operation are not described. Nothing is known about the etiology of the disease.

Angiocardiography↗
PubMed1982

[Studies on bacteriologic contamination of potassium chloride solution 25% in multidose containers regularly used on hospital wards].

The use of multidose containers poses the problem of in-use microbial contamination. In a clinical investigation sterility tests of 25% potassium chloride solution (w/v) in multidose containers have been performed in-use on two surgical wards. The contents of 80 vials used for 1, 3, 7 or 10 days (with registered withdrawals) were sterility tested with the aid of blood agar plates. None of the 80 bottles were contaminated. It has been shown that lege artis withdrawals of 25% potassium chloride solution (w/v) from multidose containers involves a very low risk of contamination. However, the theory that contaminants have been killed must not be excluded. In final laboratory tests, multidose containers of 25% sterile potassium chloride solution (w/v) were artificially contaminated. Test microorganisms were E. coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and Staph. aureus ATCC 25923. Microbial control after 1 or 2 days storage showed absence or significant germ reduction with the experimental technique described.

Drug Contamination↗
PubMed1982

[Primary cardiac tumours: diagnosis and surgical treatment (author's transl)].

A teratoma of the cardiac skeleton, a rhabdomyoma of the right ventricle and an intramural fibroma in the left ventricle were observed in three children, aged eight weeks, eight months and eight years, respectively. Atrial myxoma was found in a 42-year-old and a 49-year-old patient. History and symptoms showed no particular common features in the various patients, merely signs of flow obstruction in four of the five patients. Amongst specific cardiological diagnostic methods only angiocardiography was reliable in the demonstration of intra- or paracardiac space-occupying lesions. All five patients were successfully operated on under cardiopulmonary bypass. The surgical technique varied according to localisation, extent of the tumour and its site in relation to essential cardiac structures. Follow-up examination indicated that the patients were free of symptoms and recurrence.

Adult↗
PubMed1980

Conduit-integration in correction of right ventricular outflow obstruction.

A new method for correction of right ventricular flow tract obstruction is described. The method combines the advantages of patch-plasty-procedure and external valved conduit by conduit integration into the right ventricular and pulmonary arterial wall. Good results had been achieved in 3 cases (2 cases of Fallot's tetralogy and one case of double outlet right ventricle).

Abnormalities, Multiple↗
PubMed1979

Management of extensive lesions of the lower trachea using emergency cardiopulmonary bypass.

Rapid cardiopulmonary deterioration in patients with extensive lesions of the lower trachea presents a serious challenge in the emergency care. Conventional methods may prove inadequate to achieve airway control and to stablilize the critical condition. Severe airway obstruction and/or massive air leakage are the main causes of failure. An aggressive operative approach is mandatory. Institution of emergency cardiopulmonary bypass for resuscitative purposes and definitive surgical repair of those life-threatening uncommon tracheal lesions seems essential to us. Two cases, managed according to this concept, are presented.

Adult↗
PubMed1979

Antibiotics from basidiomycetes. IX. Oudemansin, an antifungal antibiotic from Oudemansiella mucida (Schrader ex Fr.) Hoehnel (Agaricales).

From mycelial cultures of Oudemansiella mucida a crystalline optically active antibiotic, oudemansin (2), has been isolated; its structure is closely related to strobilurin A (1). The relative configuration of oudemansin have been determined by X-ray analysis. The antibiotic exhibits strong antifungal properties and inhibits respiration in fungi, cells of the ascitic form of EHRLICH carcinoma, and rat liver mitochondria.

Agaricales↗
PubMed1979

Antibiotics from basidiomycetes. VII. Crinipellin, a new antibiotic from the basidiomycetous fungus Crinipellis stipitaria (Fr.) Pat.

A crystalline antibiotic, which we have named crinipellin, was isolated from submerged cultures of the basidiomycete Crinipellis stipitaria, strain No. 7612. High resolution mass spectrometry yielded the formula C22H28O5. The antibiotic is most active against Gram-positive bacteria, although yeasts and filamentous fungi are affected to a lesser extent. Crinipellin exhibits high in vitro inhibitory activity against the ascitic form of EHRLICH carcinoma. The incorporation of precursors of DNA-, RNA-, and protein syntheses in EHRLICH carcinoma (and in Bacillus brevis) cells was completely inhibited at 5(10) microgram/ml. In Bacillus brevis the inhibition of the incorporation of uridine was found to be due to an interference by crinipellin with the transport of the precursor into the cells.

Agaricales↗
PubMed1979

[Complete heart block and pacemaker therapy in children (author's transl)].

The etiology of congenital and acquired complete heart block is discussed. The prognosis is much better in mostly congenital suprabifurcational blocks, than in the infrabifurcational blocks, which are acquired in most instances. Suprabifurcational blocks are characterized by normal QRS complexes, higher heart rates, and adequate frequency adaptation to exercise. Widened and deformed QRS complexes and fixed heart rates as low as 40--50 beats per minute are typical in infrabifurcational blocks. Whereas children with congenital heart blocks only eventually need pacemakers, the immediate implantation of a pacemaker is mandatory in children with acquired heart blocks after a decrease of the heart rate below 30--40 beats per minute and/or after an Adams-Stokes attack. With demand pacemakers being available, fixed rate systems are obsolete for children. Lithium batteries should be preferred for their smallness and their larger life span. A considerable body of surgical and technical problems due to infection, wire damage, and other complications still awaits solution.

Adolescent↗
PubMed1978

Demonstration in human atrial preparations of alpha-adrenoceptors mediating positive inotropic effects.

In isolated, electrically driven right auricular strips of the human heart the inotropic effect of phenylephrine was studied. 1. First, the influence of the driving rate on the tension developed (i.e., the frequency-force relationship) was determined by stimulation of the preparations at 0.1, 0.5, 1, 2 and 3 HZ. The force of contraction was lowest at a stimulation rate of 0.1 HZ (36.9 g/g dry weight). The maximally developed force of contraction observed at frequencies of 0.5, 1 and 2 HZ amounted to about 200 g/g dry weight. The values did not significantly differ from each other. 2. The negative log of the EC50 (-log EC50) for the positive inotropic effect of phenylephrine determined at a frequency of 0.5 and 1.0 HZ amounted to 5.28 +/- 0.08 and 5.34 +/- 0.11, respectively. The alpha-adrenolytic drug phentolamine (3 x 10(-6) M) diminished significantly the -log EC50 to 5.01 +/- 0.04 and 4.89 +/- 0.10, respectively. 3. At a frequency of 1 HZ a shift of the concentration-response curve to the right was observed after treatment with the beta-adrenolytic drug pindolol (3 x 10(-8) M); the -log EC50 of phenylephrine decreased significantly to 4.08 +/- 0.07. 4. From these results it is concluded that alpha-adrenoceptors are present in human atria; they mediate positive inotropic effects and are stimulated by phenylephrine.

Heart↗
PubMed1978

Prevalence of intrahepatic cholestasis of pregnancy in Chile.

The prevalence of intrahepatic cholestasis of pregnancy was studied immediately postpartum in 869 women from three distant Chilean cities differing in climate and food supply. Cholestatic jaundice of pregnancy was detected in 2.4% and pruritus gravidarum in 13.2%, without significant differences between the three cities. Every woman was then ethnically classified as predominantly Caucasoid, Araucanian Indian, or Aimara Indian. A significantly higher prevalence of cholestatic jaundice of pregnancy (5.5%) and pruritus gravidarum (22.1%) was found in Araucanians than in Caucasoids (2.5% and 12.6% respectively) or in the Aimaras (0 and 11.8% respectively). The prevalence of intrahepatic cholestasis of pregnancy in Araucanians increased directly with the degree of "ethnic purity." Recurrence of the disease in multiparous women was also greater in Araucanians (13.8%) than in Caucasoids (5.5%) or in the Aimaras (3.9%). We propose that an ethnic predisposition to develop intrahepatic cholestasis of pregnancy is present in Araucanian women and that the high prevalence of the disease in Chile is mainly influenced by ethnic admixture with this South American Indian (ethnic) group.

Adult↗