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Biomedical subjects

W Fürst

Publications and source records attributed to W Fürst.

At least 55 records · Page 3Linked to original sources
PubMed1987

Identity of the activator proteins for the enzymatic hydrolysis of sulfatide, ganglioside GM1, and globotriaosylceramide.

The activator protein for the enzymatic hydrolysis of sulfatide, ganglioside GM1, and globotriaosylceramide was purified from human kidney, brain, and urine. As far as they could be assayed, these three activities cochromatographed during all steps, indicating that they are due to the same protein. This result was corroborated by immunochemical comparison of individually purified activator preparations. In contrast, the activator for ganglioside GM2 hydrolysis could clearly be separated from the other activities. Kinetic data were determined for the interaction of the sulfatide activator with the different glycolipids and hydrolases.

Brain Chemistry↗
PubMed1987

[The effect of ion pair formation on the pharmacokinetic properties of drugs. 1. The effect of alpha-methylpalmitic acid on the pharmacokinetics of quinine in rabbits].

The transport of quinine through artificial lipid membranes is significantly increased by use of alpha-methylpalmitinic acid (alpha-MPS). Using rabbits it could be shown that the alpha-MPS causes a significant increase of the mean resistance time (MRT) of quinine. Besides the alpha-MPS causes an increases Cmax and a shorter tmax of the quinine blood levels.

Animals↗
PubMed1987

[Preparation of a cytostatic-containing bone cement].

Local application of cytostatic during therapy of tumors in bones is desirable. In these cases the drugs had to be incorporated in bone glue. Liberation, stability and side-effects have been estimated using methotrexate and doxorubicin (Adriblastin) in vitro. The liberation were determined in combination with auxiliary substances and even solidity of the bone glue was maintained.

Antineoplastic Agents↗
PubMed1987

[Drug transport through artificial lipoid membranes. 21. Ion pair transport with alkyl salicylic acids].

Using hexylsalicylic acid it was demonstrated that alkylated derivatives of salicylic acid are able to increase partition and transport of ionized basic drugs across lipophilic membranes. The influence of different donor concentrations on the relation of transport was studied by means of pholedrine in combination with hexylsalicylic acid. In order to explain the mechanism of the ion-pair-transport experiments were carried out which show beside the mentioned increase of transport the occurrence of a countertransport of protons and lithium-ions, respectively. The lipophilic counterion hexylsalicylate acts inside of this mechanism as a carrier for the ionized drugs.

Chemical Phenomena↗
PubMed1987

[The effect of ion pair formation on the pharmacokinetics of drugs. 2. The effect of hexylsalicylic acid on the pharmacokinetics of quinine].

The influence of the hexylsalicylic acid (2) on the pharmacokinetic of the quinine (1), was studied using rabbits. It could be observed that after i.v. application the mean resistance time (MRT) of 1 was increased by means of ion-pair-formation with 2. But the AUC of 1 was not influenced. After rectal application of the combination 1/2 an acceleration of the 1 absorption could be pointed out. The kinetic parameters of 2 were not increased significantly if 1 was applicated simultaneously.

Administration, Rectal↗
PubMed1987

[Possibilities for the in vitro evaluation of bioavailability. 5. Compact peroral agents with basic drugs].

Lipophilic, basic drugs can be transported across lipoid-membrane even if the part of the substance being not ionized in the solution is very low. Therefore the resorption model can be used for the control of drugs containing the substances as salts. In the case of 4 substances no differences could be found concerning half transport time between the aqueous solutions and the drugs.

Administration, Oral↗
PubMed1985

[Dissolution processes and surface changes. 3. Determination of the surface with the BET process].

Two methods are demonstrated for the determination of the surfaces of solid substances by the BET-method. Using a newly constructed apparatus substances with high specific surfaces can be determined by the two-point-method with a good precision. For the determination of pulverous drugs we used the one-point-method proposed by Haul and Dümbgen [2] improving it in calibration und practicability.

Chemistry, Pharmaceutical↗
PubMed1985

[Dissolution processes and surface alteration. 4. Determination of the "effective" surface].

A method is described for measuring the "effective" surface of a drug by means of dissolution parameters using the Paddle-model or a resorption-model respectively. The obtained values were compared with the specific surface which was determined by BET-technique. The "effective" surfaces obtained by means of the dissolution parameters are smaller than those determined BET-technique.

Diffusion↗
PubMed1984

[Drug permeation through artificial lipid membranes. 17. The mechanism of ion pair transport].

The transport of ionized drugs across lipoid membranes can be increased considerable by lipophilic counter ions. This is caused by an increased lipophilicity of the ion pair which is formed between the ionized drugs and the lipophilic counterion. Caused by their very strong solubility in the membrane the lipophilic counterions accumulate and act like a carrier for the ionized drugs. Then the necessary compensation of the charges can take place by protons or other suitable ions of the used solution.

Biological Transport↗