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Biomedical subjects

D Richter

Publications and source records attributed to D Richter.

At least 379 records · Page 21Linked to original sources
PubMed1979

The stimulation of Escherichia coli stringent factor-dependent synthesis of guanosine 3',5'-polyphosphate [(p)ppGpp] by rat liver ribosomal proteins.

The effect of groups of proteins from rat liver ribosomes on the Escherichia coli stringent factor-catalyzed synthesis of (p)ppGpp was tested. Most groups were capable of supporting (p)ppGpp synthesis; the exceptions were A40, B140, B240 and B160 which contain proteins which are relatively less basic than those in the active groups. The capacity of 30 individual rat liver ribosomal proteins to activate stringent factor was assessed; most sustained the synthesis of (p)ppGpp. Proteins S12, S21, L12, P1, and P2 (which are acidic or relatively acid) had no activity; proteins S6, S8, and L3 were the most active: the others had moderate activity.

Animals↗
PubMed1979

Difficulties in the use of D-penicillamine in the treatment of rheumatoid arthritis.

The difficulties encountered in administering D-penicillamine to 40 patients with rheumatoid arthritis (RA) over a six to 24 month period are recorded. Side-effects were frequent. Proteinuria occurred in 13 patients (33%) mainly in the fourth to the sixth month. Renal biopsies were performed in six patients and all showed light microscopy abnormalities. Electron microscopy performed in five patients revealed subepithelial deposits in all and in addition some had mesangial and subendothelial deposits. Seven patients (17.5%) developed eight episodes of thrombocytopaenia which was quickly reversed on cessation of treatment or reduction in dosage. On the positive side, there was significant improvement in most parameters of disease activity at six, 12 and 18 months compared to the pretreatment levels, but the results at two years were less impressive. Reduction in steroid dosage was considerable and was greater than half the mean pretreatment dose after two years but the absence of a control group makes the full significance of these uncertain. Patients on high and low dosage regimens were compared over a 12 month period of treatment. Although the differences were not statistically significant, withdrawals and side-effects were less frequent in the low dose group.

Adolescent↗
PubMed1979

[Pressing problems of after care of patients with cancers of the cervix and corpus uteri].

A modern and optimal follow-up treatment of patients with uterine cancer requires a detailed knowledge of this disease and its sequelae. Incidence and localisation of cervical and endometrial cancers as well as kind and incidence of therapeutical side effects are demonstrated in the cases of the Gynecological University Hospital of Freiburg, GFR. A study of the psychosexual situation 2--4 years after therapy of uterine cancer is reported. Actual state of social assurances for cancer patients in the German Federal Republic is pointed out. The dates allow to draw conclusions for the follow-up of individual cases.

Adult↗
PubMed1979

Opioid activity of delta O-endorphin in the guinea pig ileum.

The oligopeptides beta- and delta O-endorphin were isolated from porcine and bovine pituitary respectively. Their opiate activity was determined in the guinea pig ileum and compared to that of the pentapeptide methionine-enkephalin and morphine. The rank order of opioid activity was found to be: morphine greater than beta-endorphin = Met-enkephalin greater than delta O-Endorphin which lacks the four C-terminal amino acids of beta-endorphin displayed 60% of the activity of beta-endorphin. These results indicate, that C-terminal amino acids contribute little to the affinity of beta-endorphin for opiate receptors in the guinea pig ileum.

Animals↗
PubMed1979

[Daytime rooming-in--a contribution to family-oriented obstetrics (author's transl)].

Rooming-in of mother and child during the puerperium is an essential step towards family-oriented obstetrics. However, the setting-up of full rooming-in wards is often prevented by problems of organisation, personnel, cost and space. It is here where the reorganisation of conventional maternity wards to daytime rooming-in wards can be regarded as a feasible alternative, since it requires low investment cost and moderate expenditure of effort required for satisfactory working. At the Freiburg University Gynaecological Hospital, 1028 women were asked to choose between a conventional ward and a daytime rooming-in ward. The article reports on experience collected during the reorganisation of this ward as well as on the behaviour, reactions and requests on the part of the mothers. The high degree of positive acceptance as well as the easy adaptability of this maternity ward system to existing conditions, favour widespread introduction of the daytime rooming-in system.

Adult↗
PubMed1978

Characterization of the guanosine 5'-triphosphate 3'-diphosphate and guanosine 5'-diphosphate 3'-diphosphate degradation reaction catalyzed by a specific pyrophosphorylase from Escherichia coli.

Guanosine 5'-triphosphate 3'-diphosphate (pppGpp) and guanosine 5'-diphosphate 3'-diphosphate (ppGpp) are specifically degraded by a manganese-dependent pyrophosphorylase present in spoT+ but not in spoT- strains of Escherichia coli, indicating that the enzyme is the spoT gene product. The enzyme catalyzes the release of pyrophosphate from the 3' position of ppGpp or pppGpp, yielding ppG and pppG, respectively; pppGpp could not be detected as an intermediate in the decay reaction. Degradation of (p)ppGpp is optimal in the presence of 200 to 300 mM potassium or sodium acetate, at a pH of 7.5 to 8 and a temperature of 37 degrees C.

Escherichia coli↗
PubMed1978

Eukaryotic ribosomal proteins stimulate Escherichia coli stringent factor to synthesize guanosine 5'-diphosphate, 3'-diphosphate (ppGpp) and guanosine 5'-triphosphate, 3'-diphosphate (ppGpp).

When supplemented with Escherichia coli stringent factor, 80S ribosomes from various sources failed to support guanosine tetra- and pentaphosphate ((p)ppGpp) synthesis. In contrast, ribosomal proteins from 80S, 60S or 40S particles (mouse embryos, rabbit reticulocytes) crossreacted with the E. coli stringent factor. Significant stimulation of (p)ppGpp synthesis was achieved with a concentration as low as 5 micrograms of ribosomal proteins/ml. These observations may provide additional crtieria to detect homologies between eukaryotic and prokaryotic ribosomal proteins.

Bacterial Proteins↗
PubMed1978

Degradation of guanosine 3'-diphosphate 5'-diphosphate in vitro by the spoT gene product of Escherichia coli.

Guanosine 3'-diphosphate 5'-diphosphate (ppGpp) is rapidly degraded to guanosine 5'-diphosphate (ppG) and probably pyrophosphate by an enzyme present in the ribosomal fraction prepared from spoT+ strains of Escherichia coli. The ppGpp-degrading enzyme was released from the ribosomes during dissociation at low ionic strength. Ribosomes are not essential for degradation of ppGpp, and decay of ppGpp is strictly dependent on manganese ions. The reaction is sensitive to inhibition by tetracycline, which can be reversed by MnCl2, indicating that the inhibitory effect is due to the previously described chelating properties of the antibiotic. When the ppGpp-degrading enzyme was complemented with adenosine 5'-triphosphate (pppA) and a nucleoside diphosphate kinase, decay of ppGpp was accelerated yielding pppG and ppG as major products. In the absence of pppA we have been unable to detect the ppGpp-degrading enzyme in various spoT- mutant strains indicating that this enzyme is the spoT gene product.

Escherichia coli↗
PubMed1978

[Secondary amenorrhoea (author's transl)].

27 patients with secondary amenorrhoea for 6--20 months were investigated with a gonadorelin (GnRH-)test and a psychoanalytical exploration. Results, which were determined independently of each other, were then correlated. According to the gonadorelin and the gestagen test patients could be allocated to four groups: test group 1 = negative gestagen test, LH peak below 8 ng/ml, test group 2 = positive gestagen test, LH peak below 8 ng/ml, test group 3 = positive gestagen test, LH peak 8--20 ng/ml, test group 4 = positive gestagen test, LH peak 20--37 ng/ml. According to the psychoanalytical exploration two groups of patients could be differentiated. Patients of test group 1 and 2 showed psychosomatic disorders to a greater extent with pronounced associated somatic symptoms and predominantly retentive personality structures. Patients in test groups 3 and 4 showed predominantly associated mental symptoms accompanied by better insight into their own conflicts.

Adult↗
PubMed1978

Mechanism of the in vitro breakdown of guanosine 5'-diphosphate 3'-diphosphate in Escherichia coli.

Degradation of guanosine tetraphosphate (ppGpp) involves an enzyme associated with the ribosomal fraction from spoT+ strains of Escherichia coli. Double-label experiments with pp[3h]gpp, pp[3H]Gpp, or pp[3H]Gpp as substrate strongly suggest that ppG is the degradation product and that the enzyme releases two phosphates coordinately from the 3' position of ppGpp. In the absence of pppA this reaction proceeds in an uncoupled fashion, yielding ppG and PPi, but in the presence of pppA the decay is considerably enhanced and a pppA-ppi exchange reaction occurs in which the 3'-pyrophosphoryl group of ppGpp displaces the gamma and beta phosphates of pppA. Sodium PPi at 4 m7 inhibits decay of ppGpp regardless of whether or not pppA is present.

Diphosphates↗