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Biomedical subjects

R Hammer

Publications and source records attributed to R Hammer.

At least 91 records · Page 5Linked to original sources

Involving community representatives in CMHC evaluation and research.

The participation of community representatives and consumers of services in agency planning has been mandated by legislation and the subsequent regulations. However, the representatives' lack of technical knowledge and sophistication frequently makes them unequal participants in the decision-making process. To help increase such sophistication, the program analysis and evaluation section of a large community mental health center has involved or assisted patient and community volunteers in various evaluation and research projects; they include a survey of area housing conditions, a survey of the needs of former inpatients, an evaluation of programs operated by a coalition of community groups, and a community resource listing.

Community Mental Health Services↗

[Ambroxol, comparative studies of pharmacokinetics and biotransformation in rat, rabbit, dog and man (author's transl)].

Pharmacokinetics and biotransformation of trans-4-(2-amino-3,5-dibromo-benzylamino)cyclohexanol hydrochloride (ambroxol, NA 872 Cl) was studied using the 14C-labelled compound. Absorption after oral administration was found to be fast and complete. Elimination half-life of radioactivity in the blood was estimated as 20--25 h in rat, dog and man and as 2 h only in rabbit. This apparent elimination half-life is governed by the disposition of acidic metabolites of NA 872. In man and rabbit radioactivity is excreted almost completely into the urine, whereas in rat and dog biliary excretion is also observed. Routes of biotransformation are similar in all 4 species. NA 872 is metabolized by phase I reactions to NA 873 and finally to dibromoanthranilic acid. Phase II reactions with the parent compound and metabolites are observed mainly in man and rabbit.

Ambroxol↗

[Ambroxol, studies of biotransformation in man and determination in biological samples (author's transl)].

15 mg trans-4-[2-amino-3,5-dibromo-benzyl)-amino]-cyclohexanol-hydrochloride (ambroxol, NA 872) was administered i.v. and orally to healthy volunteers. The metabolic pattern in urine and plasma was similar for both routes of administration. Biotransformation reactions are straightforward, yielding two major products of phage I reactions identified as 6,8-dibromo-3-(trans-4-hydroxycyclohexyl)-1,2,3,4-tetrahydro-quinazoline and 3,5-dibromo-anthranilic acid. These metabolites as well as the parent compound are also converted to conjugates, predominantly glucuronides. Quantification of unlabelled ambroxol in biological fluids is achieved by radiochemical derivatisation with 14C-labelled formaldehyde in imitation of the biotransformation.

Administration, Oral↗

[Alterations in pharmacokinetics during toxicity tests (author's transl)].

Some possible reasons are discussed which may lead to changes in the pharmacokinetics of a drug during long-term toxicity tests. Since most of these alterations have toxicological consequences, their evaluation can be helpful in the interpretation of toxicity studies. Furthermore, and altered pharmacokinetic profile may be a diagnostic tool for the detection of organ damage (e.g., eliminatory organs). In this paper three examples of the "radioactive test dose method" are shown. This method allows a direct comparison of the pharmacokinetics between pretreated animals and controls by administration of a single radioactive test dose to both groups.

Adaptation, Physiological↗

Sex differences in Necturus urinary bladders.

We describe morphological sex differences in urinary bladders of the urodele amphibian Necturus maculosus. The mucosal epithelial cells of bladders from males were tall and contained considerable PAS-positive material. In scanning electron micrographs of the mucosal surface, epithelial cells from male bladders were well demarcated and were capped with microplicae or with long cilia. The mucosal epithelial cells of bladders from females were low and contained only a small amount of PAS-positive material; in scanning electron micrographs cell boundaries could not be distinguished and no cilia or microplicae were present. Bladders from males had higher transepithelial potential difference and lower water content than bladders from females. Urine analyses were not significantly different in the two sexes. It is suggested that response to androgens in the male accounts for the observed differences.

Animals↗

Possible programmatic consequences of community mental health center funding arrangements: illustrations based on inpatient utilization data.

Funding arrangements have a direct and substantial influential effect on the delivery of mental health services. Despite the original intent of the community mental health center philosophy, centers have not been freed from programmatic limitations imposed by the fiscal systems. The focus of this article is the inpatient unit that has the key role as relates to a center's ability to raise revenue. Using data from a study of community mental health center inpatient utilization patterns, the authors demonstrate that centers face the problem of becoming revolving doors (for a recidivist population). Existing fiscal arrangements, it is suggested, reinforce this pattern and tend to downplay innovative alternatives to traditional inpatient care.

Ambulatory Care↗

Pharmacokinetics as an aid in the interpretation of toxicity tests.

A method is described which makes the detection of alterations in the pharmacokinetic profile possible when substances are administered during long-term toxicity tests. By superposition of a radioactive dose at the end of the toxicity study a blood level can be obtained which--on the assumption of first-order kinetics--is comparable to that after a single radioactive dose in controls. Differences between blood levels of pretreated and control animals may indicate enzyme induction or damage of the elimination organs, etc., even when morphological changes are evident.

Ambroxol↗

Model building in pharmacokinetics/Part V: Simulation of blood level curves following repetitive dosing and their experimental verification (author's transl).

An equation is given to describe the plasma level curve of any linear compartment model following multiple dosing of various doses after various time intervals. The equation is especially suitable to be used with desk top computers equipped with a plotting device. A dosage regimen can be simulated using the parameters derived from single dose experiments. Experimental check-up of the predicted curves is necessary and illustrated by two examples. Systematic deviations from the prediction indicate changes in the biological system, e.g., in absorption, by enzyme induction, saturable processes, etc.

Anti-Inflammatory Agents↗

[Pharmacokinetics and metabolism of the antiinflammatory agents S-H 766 in man].

Blood and plasma levels as well as urinary and fecal excretion were measured in humans after oral administration of radioactively labelled 4-[j-(2'-fluorobiphenylyl)]-4-hydroxycrotonic acid (S-H 766 MO). The radioactivity in the plasma reaches maximum values of about 10 mug eq./ml 1 to 2 h after application with either form. After repeated administration good agreement is found between the plasma levels measured and those simulated according to the pharmacokinetic parameters obtained after single application. The S-H 766 metabolites were investigated in blood and urine. The substance was found to undergo considerable metabolism, only approximately 2% being excreted in the urine unchanged. The conjugates, which constitute over 60% of the radioactivity of the urine, consist mainly of glucuronides and sulfates. The structure of the aglycones shows that the metabolism occurs along two pathways, by beta-oxidation of the aliphatic side chain into aryl acetic acids and by hydroxylation of the aromatic nucleus to phenolic compounds. It must be assumed that these biotransformations take place both simultaneously and successively.

Adolescent↗