Biomedical subjects

P R Bock

Publications and source records attributed to P R Bock.

24 records · Page 2Linked to original sources

PubMed1976

[A time-saving method for histo-enzymatic studies of brain tissues of animals with chronically implanted electrodes by means of a hard-section microtome (author's transl)].

A time-saving method is described for the localisation of chronically implanted electrodes in the brain of test animals by means of a "Kryostat" hard section microtome which allows both histo-topographic and histo-enzymatic investigations. This is made possible by the incorporation of a three-dimensional microtome holder.

Animals↗

PubMed1976

A contribution to the pharmacokinetics of bencyclane (Fludilat) in man.

The quantitative determination of bencyclane from the biological material was carried out with the aid of a combined microchemical method (thin-layer chromatography and measurement of fluorescence) using NBD chloride. The original method [J. Reisch, Z. Analyt. Chemie, 247 (1969) 56; J. Monforte, Clinical Chemistry 18 (1972) 1329; R.S. Fager, Anal. Biochemistry, 53 (1973) 290, etc.] was so modified as to enable attainment of optimal results in respect of sensitivity and accuracy in the determination of bencyclane. The sensitivity of this modified method is 0.1 mug/ml plasma. Volunteer subjects and patients received under standard conditions 2 coated tablets Fludilat (i.e. 200 mg bencyclane hydrogen fumarate) orally as a single dose or repeated 3 times daily over 5 days, or 4 ampoules (= 200 mg) in a single intravenous injection. After a single oral administration, maximum plasma concentrations of approximately 2 mug/ml were attained in about 2 hours. The elimination half-life was about 360-480 min. The appearance of a second peak after about 6-7 hours indicates involvement of several compartments. On intravenous administration, maximum plasma concentrations of above 2 mug/ml were attained. A second peak in the late phase of the elimination was also detected here. The repeated oral administration led to maximum plasma concentrations of above 3 mug/ml without there being any indication of accumulation. Protein binding of about 30% was determined with the aid of the equilibrium dialysis method. A parallel "in vitro" study with 14C-bencyclane (U.R. Kleeberg, 1973, unpublished) showed an approx. 40% protein binding, an approx. 30% erythrocyte binding, and an approx. 10% thrombocyte binding. About 20% bencyclane remain free.

Administration, Oral↗

PubMed1976

Visually evoked potentials in cortical and subcortical brain structures of conscious rabbits with chronically implanted electrodes. Standardized normal values and the influence of some psychopharmacological agents on them.

By means of a modified and simplified surgical and implantation technique, standardized values for visually evoked potentials (EP) from 7 brain structures (caudate nucleus, posterior hypothalamus, mesencephalic reticular formation, intra-laminar thalamic nuclei, amygdala, dorsal hippocampus and visual cortex) are obtained. The importance of a careful selection of the animal material, constant test conditions and the selection of test parameters as a prerequisite for the assessment of psychotropic drugs is emphasized and discussed. As an example of the specific influence on visually evoked potentials in the above named brain structures, the effects of haloperidol and amytriptyline on latencies and amplitudes of the individual parameters of EPs are described. It is assumed that the method described can be of great assistance for investigation and classification of newly developed substances.

Amitriptyline↗

PubMed1975

Modified method for recording cortical and subcortical visually evoked potentials in the conscious rabbit with chronically implanted electrodes.

A modified stereotaxic surgical and implantation technique for animal EEG studies in rabbits is described. The use of a stereotaxic "socklet unit" with a minimum of operational equipment, high accuracy, simple handling, and good tissue compatibility permits the repetition of EEG studies in the same animal with a large number of electrodes and over a period of several months. For example for this technique an experimental arrangement for recording visually evoked potentials is described. The importance of a careful selection of the experimental animals, of maintaining constant test conditions, and of the selecting of test parameters as a prerequisite for assessing induced alterations is emphasized and discussed.

Amygdala↗

PubMed1975

[A modified method for the determination of locations of chronically implanted electrodes in rabbit brains (author's transl)].

A fast and simple method is described for the localisation of tips of chronically implanted electrodes in the brain of rabbits which may be obtained--under standard conditions--by an intra-aortal injection of a 2% potassium-hexacyanoferrate-III solution. This method also facilitates histological preparations with a thickness of 5 mu only and thus permits a thorough morpho-pathological examination not only in the area of the electrode tips but in adjacent zones as well. The use of a buffered formalin solution also permits certain histochemical examinations to be made, for instance the determination of nucleic acids.

Animals↗

PubMedDate not supplied

Influence of postoperative complementary treatment with lectin-standardized mistletoe extract on breast cancer patients. A controlled epidemiological multicentric retrolective cohort study.

This epidemiological study was performed to evaluate the influence of postoperative complementary treatment with lectin-standardized mistletoe extract (sME) on breast cancer patients. The design (retrolective cohort analysis with parallel groups) and conduct of the study were in agreement with current standards for prospectively randomized clinical trials. A cohort of 1,248 breast cancer patients on postoperative chemo-, radio-, hormone-therapy were studied in 27 randomized centers. Patients with complementary medications other than sME were excluded from the evaluation and the final analysis was performed on data of 689 patients. From this cohort 219 patients received a complementary treatment exclusively with sME (therapy group), while 470 patients were without complementary treatment (control group). The median follow-up time was 284 days (therapy group) and 285 days (control group). The primary end-point of the study was to determine the impact of complementary sME treatment on disease- or therapy-induced adverse reactions in breast cancer patients. Imbalances for causal effects (covariates) were adjusted by propensity scores. Final evaluation was performed by estimating the linear regression between change in symptom score and propensity score with all data and using the regression line to calculate the change in symptom score expected for each patient. Tumor-associated events were evaluated by number and time until event. The safety of sME treatment was analysed in terms of number, severity, duration and outcome of adverse reactions. As compared to breast cancer patients without complementary treatment (control group), the administration of sME (therapy group) resulted in a significant reduction of adverse reactions induced by the tumor-destructive therapies (e.g. nausea, gastro-intestinal tract symptoms, depression, fatigue, mental symptoms) and prolonged relapse-free intervals, most pronounced for UICC stages IIa and IIb. The rate of sME-associated adverse reactions was 12.8%. All side-effects were mild to moderate, predominantly local skin reactions and self-limiting without therapeutic intervention. Complementary treatment of breast cancer patients with lectin-standardized mistletoe extract (sME) proved to be a well tolerated optimization of standard tumor-destructive therapies, mainly improving quality of life and relapse-free intervals in defined UICC stages.

Adult↗