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Biomedical subjects

W Petri

Publications and source records attributed to W Petri.

12 recordsLinked to original sources
PubMed1986

[Galenic and clinico-pharmacologic studies of prednicarbate (Hoe 777)].

The corticoid prednicarbate (test name: Hoe 777) is derived from prednisolone having no halogenic groups (chemical name: prednisolone-17-ethyl carbonate-21-propionate). Because of the specific physical and chemical properties of prednicarbate, galenic research strove to optimize the vehicle. Further development was only performed on those drug-containing bases showing especially good drug release (granting the most favorable action) in a) the vasoconstriction test and b) the UV erythema test practiced on volunteers with healthy skin. Exemplarily dealing with the special preparations predicarbate cream, ointment, and greasy ointment, we give some details of studies on drug dosage, vehicle selection, and the optimum water/lipid ratio.

Administration, Topical↗
PubMed1985

Comparison of various pharmaceutical preparations of prednicarbate after repeated topical administration to the skin of rats.

The following pharmaceutical preparations of prednicarbate (Hoe 777) were tested: fatty ointment 0.1% and 0.25%, ointment 0.1% and 0.25%, cream 0.1% and 0.25%, solution 0.25%. These pharmaceutical preparations were applied 10 times to the shorn back of male Sprague-Dawley rats. After sacrifice the following parameters were recorded: body weight, skin thickness as well as ultimate load, ultimate strain, tensile strength and modulus of elasticity of excised skin strips. Soluble fractions of collagen (soluble in 0.15 and 0.5 molar NaCl solution and in citrate buffer) and insoluble collagen as well as total collagen/g fresh weight were determined. The values of the treated animals were compared with the values of untreated animals and animals treated with the individual base only. As found in earlier studies prednicarbate induced a slight decrease of body weight and skin thickness. Ultimate extension and ultimate load were only barely changed. There was, however, a dose-dependent increase of modulus of elasticity and tensile strength, due to treatment with prednicarbate. Simultaneously, an increase on insoluble collagen and of total collagen per g fresh weight was noted. These results confirm previous findings, indicating a positive correlation between tensile strength and modulus of elasticity of connective tissue with the content of insoluble collagen. The effects of ointment, fatty ointment and cream are very similar, nevertheless, they depend on the type of formulation applied. In the case of prednicarbate solution the dependence of the effects upon the formulation used is very obvious. The increase of tensile strength and modulus of elasticity as well as of insoluble collagen show that very impressively.

Administration, Topical↗
PubMed1983

Accumulation of a specific subset of D. melanogaster heat shock mRNAs in normal development without heat shock.

During normal development in D. melanogaster, messenger RNAs for three of the seven heat shock proteins (hsp83, hsp28 and hsp26) accumulate in adult ovaries and are abundant in embryos until blastoderm. The three mRNAs appear to originate in nurse cells and subsequently pass, during stages 10-11, into the oocyte. Little if any of the four other heat shock mRNAs is present in unshocked ovaries or embryos at any time examined. Pre-blastoderm embryos fail to accumulate these heat shock mRNAs even if subjected to heat shock. The accumulation in normal oogenesis of mRNAs for only three of the seven heat shock proteins indicates the existence of differential, possibly multiple controls of heat shock gene expression, and suggests that heat shock proteins hsp83, hsp28 and hsp26 function in the oocyte or early embryo.

Animals↗
PubMed1983

Kinetics of UV-erythema in normal subjects.

In the expanding field of clinical dermatopharmacology we standardized an erythema model for testing drugs with effects on UV-induced inflammation in normal male Caucasian subjects. Using a light source with fibre-optic transmission and precise radiation characteristics, some of the shortcomings of conventional UV-application could be overcome. The radiation geometry during the various experiments was kept constant by a tube, permitting a defined area of exposure. Up to eight skin areas of the backs of normal volunteers were radiated with 86.2% UV-A and 13.8% UV-B. After exclusion of hyporeactive and hyperreactive subjects a good intrasubject reproducibility was obtained repeatedly over at least 3 months. According to the definition of bioavailability, our method allows the measurement of the rate and extent of UV-induced erythema. This model has been used for testing topical steroids, non-steroidal antiphlogistics in a variety of pharmaceutical formulations.

Dose-Response Relationship, Radiation↗
PubMed1981

[Liberation of ciclopiroxolamine from dermatological preparations (author's transl)].

Using 6-cyclohexyl-1-hydroxy-4-methyl-2(1H)-pyridone, 2-aminoethanol salt (ciclopiroxolamine, Cic, Hoe 296, Batrafen) cream as an example, the method for measuring the in vitro liberation from some spreadable dermatological preparations of active substance with an antimycotic action is discussed. In addition, a description is given of a test model for measuring the spreading power of cream or ointment preparations. The tests also include for comparison purposes several antimycotic preparations at present on the market. The extent to which in vitro results of liberation of active substance combined with the results obtained on spreading power permit a prediction as to the penetration and permeation behaviour of an antimycotic preparation applied dermally is discussed.

Administration, Topical↗
PubMed1976

Environmental effects on glutathione-insulin transhydrogenase in rat liver.

The dietary and hormonal regulation of the level of glutathione-insulin tranhydrogenase in rat liver was investigated in these studies. In order to make valid comparisons, the assay of glutathione-insulin transhydrogenase was performed at near zero-order kinetics wherein enzyme rate was proportional to enzyme amount. Changing the protein content of the diet or administration of glucagon or cortisone did not significantly affect the specific activity of glutathione-insulin transhydrogenase in microsomes from rat liver. However, the Vmax and Km of this enzyme in the livers of adrenalectomized rats were increased three-and fourfold over these values in microsomes from normal liver. Administration of cortisone resulted in a return to the normal kinetic constants of microsomal GIT within 4 hr.

Animals↗