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Biomedical subjects

D Hennig

Publications and source records attributed to D Hennig.

35 records · Page 2Linked to original sources
PubMed1991

Reassessment of the v-fms sequence: threonine phosphorylation of the COOH-terminal domain.

The v-fms oncogene product of the McDonough strain of feline sarcoma virus is a member of the receptor tyrosine kinase family. Its cellular counterpart, the c-fms product, is the receptor for colony-stimulating factor 1 (CSF-1) of macrophages. We have reanalyzed the v-fms gene by direct sequencing of a biologically active clone. An additional A nucleotide was detected in position 2810 of the published v-fms sequence. The frameshift changed the COOH-terminal sequence of the v-fms protein from -R-937-G-P-P-L-COOH to -Q-937-R-T-P-P-V-A-R-COOH. Antibodies against a synthetic peptide representing this new sequence precipitated the v-fms proteins from transformed NRK cells as well as from feline sarcoma virus (McDonough)-infected feline fibroblasts. We show by tryptic peptide mapping that threonine 939 present in the new sequence is phosphorylated by a yet unknown serine/threonine kinase in vivo. In chicken fibroblasts expressing the v-fms gene, this phosphorylation clearly depended on the addition of exogenous CSF-1. Furthermore, addition of CSF-1 appeared to activate the serine/threonine kinase, as judged by phosphorylation of the synthetic peptide QRTPPVAR.

Amino Acid Sequence↗
PubMed1988

Isolation of a transformation-defective mutant of the McDonough strain of feline sarcoma virus exhibiting tyrosine kinase activity in vitro but not in vivo.

NRK cells transformed by the McDonough strain of feline sarcoma virus (SM-FeSV) were mutagenized by the use of 5'-azacytidine. Four cell lines expressing different transformation-defective phenotypes were isolated. Superinfection of these cell lines with simian sarcoma-associated virus (SSAV) led in three instances to the recovery of transforming virus particles carrying an intact fms gene. A nonconditional transformation-defective virus, designated td26-SM-FeSV (SSAV), was isolated from one of the cell lines. NRK cells infected with this mutant contained actin cables and fibronectin networks and exhibited normal cell morphology. Such cells formed only small colonies in soft agar and exhibited a mitogenic activity similar to that of noninfected cells. Cells infected with td26-SM-FeSV (SSAV) synthesized a gag-fms fusion glycoprotein (gp180gag-fms). This polypeptide was processed in the normal manner into the intracellular gp120v-fms and a transformation-defective gp140td-v-fms which was expressed at the surface of infected cells. This species had an increased electrophoretic mobility on polyacrylamide gels compared with the molecule from wild-type virus.gp140td-v-fms had endo-beta-N-acetylglucosaminidase H-resistant carbohydrate side chains. No tyrosine kinase activity was detectable in vivo in td26-SM-FeSV (SSAV)-infected cells even when the cells were treated with sodium orthovanadate. In vitro, fms molecules from td26-SM-FeSV (SSAV)-infected cells exhibited tyrosine kinase activity as determined by autophosphorylation and phosphorylation of exogenous (poly)Glu-Tyr. At low ATP concentrations (less than 5 microM) this in vitro tyrosine kinase activity was significantly reduced compared with that of the wild-type counterpart.

Antigens, Surface↗
PubMed1987

[The effect of selected disintegrants on the properties of three hydrochlorothiazide tablet formulations].

The admixture of disintegrants was investigated in three different hydrochlorothiazide formulations with respect to tablet properties. Sodiumcarboxymethyl starchs, Na-CMS (Explotab, Primojel, Na-CMS AB-G.D.R.), cross-linked polyvinylpyrrolidone, CL PVP (Polyplasdone) and potato starch were applied. The investigations were especially aimed at the alteration of tablet properties in dependence on compressive force. Considering the values of decomposition and compressive strength Polyplasdone XL has been proved to be the most effective disintegrant for the hydrochlorothiazide formulations investigated. Potato starch shows the worst results. There are only slight differences between the three Na-CMS.

Drug Compounding↗
PubMed1987

[Application of polyethylene glycol (PEG) to the control of permeability of poly(meth)acrylate coatings].

Pellets with pholedrine sulphate are coated by means of a fluid-bed process with poly(meth)acrylate materials (Eudragit RS, Eudragit E 30 D, Scopacryl D 340) and varying portions of PEG 6000. In addition to influencing drug release by change of the thickness it was studied the admixture of PEG to the films. Figure logarithm permeability coefficient vs. the portion of PEG can be used to select a coating composition with wished permeability. By application of aqueous latex dispersions (Eudragit E 30 D, Scopacryl D 340) PEG dissolves completely very fast from the coatings. On the other hand if organic lac solution (Eudragit RS) is used a stagnation of the dissolution process after some min is observed. By leaching out the PEG the structure of the resulting films is loosened and therefore its permeability is increased.

Kinetics↗
PubMed1986

[The influence of plasticizers on the permeability of polymethacrylate films (Eudragit RS)].

Pellets with pholedrine sulphate are coated by means of a fluid-bed process with polymethacrylates and increasing portions of plasticizers. The addition of PEG 6000 increased the film permeability. On the other hand triacetin effected no change and dibuthyl phthalate decreased the permeability in relation to films without plasticizers. When the films were contacted 8 h with phosphate buffer (pH = 7,4) PEG could not be detected and triacetin film contents was reduced to about 30%. Unlike that the portion of dibuthyl phthalate decreased insignificantly.

Dibutyl Phthalate↗
PubMed1986

[The in vitro liberation behavior of quinidine from drug forms with prolonged release by various liberation methods].

The liberation behaviour of the following preparations were tested using two models: Chinidin-Duriles (Astra, Sweden), Chinidin-longo (VEB Isis-Chemie Zwickau, GDR), Chinidin-retard-Isis (VEB Isis-Chemie Zwickau, GDR). The received data were estimated by multivariate statistical methods. It was found, that the three tested preparations are different in their liberation behaviour. Moreover it was shown, that there are differences between the two apparatus. Nevertheless both methods are able to characterize the liberation behaviour of the three preparations.

Chemistry, Pharmaceutical↗
PubMed1985

[The stability of hydrochlorothiazide and cyclopenthiazide in various drug forms. 2. The stability of Disalunil tablets].

Checking-up the stability of hydrochlorothiazid tablets (Disalunil), chemical and especially pharmaceutical-technological analyses were forming part of the adequate test programme. The pharmaceutical and chemical properties of the Disalunil tablets will be regarded as sufficient ones at normal conditions of their storage. In case the tablets will be stored, however, in their original packing under conditions of an increased humidity or with additional water, the water sorption will result in prolonged disintegration rates as well as in a reduced radial breaking strength and dissolution rate. This significant depreciation of the drug cannot be recognized by chemical-analytical methods.

Cyclopenthiazide↗
PubMed1985

[Use of poly(meth)acrylates for the control and release of pholedrine sulfate from microdragees].

Pellets with pholedrine sulphate are coated by means of a fluid-bed process with six different poly(meth)acrylate coating materials. The coatings showed drug release widely different. A wide pH-independent release showed film-coated pellets with Eudragit RS, RL and E 30D as coating material. By application of Scopacryl D 336, D 339 and D 340 the acceleration of liberation by the pH-value of 7,4 is related to the increasing amount of acrylic acid in polymer. The rate of release can be controlled by mixing coatings with different permeability in wide range. Diagram of logarithm permeability coefficient against the mixing proportion can be used for selection a coating composition with wished permeability.

Capsules↗
PubMed1984

Biological and biochemical characterization of a new isolate of feline sarcoma virus: Theilen-Pedersen (TP1-FeSV).

A new feline sarcoma virus designated Theilen-Pedersen (TP1-FeSV) has been isolated from a spontaneous, slowly growing fibrosarcoma of a domestic short-haired 4-year-old castrated cat. The virus codes for a gag-onc fusion protein of 83,000 molecular weight phosphorylated in vivo at serine, threonine, and tyrosine residues. Cells transformed in vitro with TP1-FeSV exhibit five- to 10-fold elevated levels of phosphotyrosine over FeLV-infected cells. The gag-onc polyprotein has associated with it a tyrosyl protein kinase activity which in vitro results in autophosphorylation of the molecule at tyrosine residues. The fusion protein cannot be labeled metabolically with [3H]glucosamine and tunicamycin has no effect on the electrophoretic mobility of the in vivo [32P]orthophosphate-labeled fusion protein. The fusion protein, in common with the gag precursor Pr65gag, can be metabolically labeled with palmitic acid.

Acylation↗
PubMed1983

[Construction, operation and initial experience with a laboratory apparatus for fluid-bed coating of particles].

Starting from the developmental work of Dittgen and co-workers [1] and of Gröning [2], the authors constructed an air-suspension device which permits to coat crystals, granules and pellets on a laboratory scale. The device developed is a glass apparatus for coating almost 10 g of particles. The motion of the particles to be coated is characterized by a high-speed rotation on a circular orbit associated with a raise by the air current and a fall caused by gravity. This combined motion prevents the development of zones of varying particle sizes. The usefulness of this apparatus is demonstrated by the example of the application of a polyacrylate depot coating to pholedrine sulphate and quinidine sulphate pellets. Scanning electron micrographs are used for the optical assessment of the coating.

Methamphetamine↗
PubMed1979

[Effectiveness of electrotherapy on the pressure of the urethral sphincter].

In 4 out of 6 patients the effectivity of the swelling current therapy on the profile of the urethra-pressure could be proved, in which case in the functional length of the urethra as well as in the maximum occlusion pressure of the urethra an increase was to be seen in contrast to the profile without swelling current.

Adenoma↗