Evidence that in chick embryos destruction of hepatic microsomal cytochrome P-450 haem is a general mechanism of induction of delta-aminolaevulinate synthase by porphyria-causing drugs.

A variety of prophyrinogenic compounds were tested for their effect in ovo on chick-embryo liver microsomal cytochrome P-450 haem concentration and mitochondrial delta-aminolaevulinate synthase activity. With all drugs tested, there was a 30--50% decrease in cytochrome P-450 haem concentration within 1 h of treatment, and this was closely followed by an increase in delta-aminolaevulinate synthase activity. The relationship was independent of the extent of enzyme induction and is consistent with the proposal that drug-mediated destruction of cytochrome P-450 haem is the primary mechanism of induction of delta-aminolaevulinate synthase.

Developing competence in problem solving. A behavioral model.

Problem solving is an integral part of effective physical therapy practice. A model depicting the behaviors of the problem solver while solving problems is presented. The behaviors are related to each step in the problem-solving process and to cognitive, affective, and psychomotor functions of individuals.

[Occupational liver diseases: (author's transl)].

A large number of exogenous substances with potential liver toxicity are to be found in work places and in the environment. Decisive importance is ascribed to regular supervision of exposed persons and adhering to the appropriate safety provisions without being able to ensure reliable prevention of toxic liver damage thereby. The prognosis of occupational toxic liver damage is good if recognition is timely and the causal noxae are eliminated.

Joint segregation of biochemical loci in Salmonidae. II. Linkage associations from a hybridized salvelinus genome (S. namaycush X S. fontinalis).

The results of more than 300 pairwise examinations of biochemical loci for joint segregation in brook trout (Salvelinus fontinalis) and in the hybridized genome of lake trout (S. namaycush) X brook trout are summarized. Nineteen loci have been assigned to tahe following eight linkage groupings on the basis of nonrandom assortment, including cases of both classical linkage and pseudolinkage: ODH with PMI with PGI-3, PGI-2 with SDH, ADA-1 with AGP-2, AAT-1(1,2) with AGP-1 with MDH-1, MDH-3 with MDH-4, LDH-3 with LDH-4, IDH-3 with ME-2 and GUS with CPK-1.

Pseudolinkage of the duplicate loci for supernatant aspartate aminotransferase in brook trout, Salvelinus fontinalis.

Electrophoretic variation involving three alleles is described for the duplicated loci for supernatant aspartate aminotransferase (AAT-1,2), from muscle extracts of brook trout. Both loci exhibit largely disomic inheritance. Exceptional progeny types are proposed to be the result of a form of tetrasomic inheritance.

Haem control in experimental porphyria. The effect of haemin on the induction of delta-aminolaevulinate synthase in isolated chick-embryo liver cells.

2-Allyl-2-isopropylacetamide-mediated induction of hepatic porphyria was studied in isolated chick-embryo liver cells. Increased delta-aminolaevulinate synthase activity occurred within 1h of induction and continued to increase for 8h. Protoporphyrins synthesized during this time accumulated to a concentration 10-fold greater than that in the control.

Effect of spinal cord temperature on carotid blood flow in the Pekin duck.

Spinal cord heating in white Pekin ducks increases breathing rate and carotid blood flow. During naturally induced panting, the reverse effect was achieved by spinal cooling. An increased beak and expired air temperature during spinal heating suggest an importance of the increased carotid blood flow in maximizing heat dissipation during polypnoea.

Synthesis of delta-aminolaevulinate synthase in vitro using hepatic mRNA from chick embryos with induced porphyria.

Polyadenylated mRNA was isolated from chick embryo liver following induction of hepatic porphyria. The RNA was translated in vitro using a wheat germ cell-free system and delta-aminolaevulinate synthase was identified in the translation products by indirect immunoprecipitation. The enzyme was not apparent in the translation products of polyadenylated RNA from non-induced livers.

Genetic basis of creatine kinase isozymes in skeletal muscle of salmonid fishes.

The genetic basis of isozyme phenotypes of creatine kinase (CK) from extracts of skeletal muscle of salmonids has been resolved through breeding data including double heterozygous crosses and backcrosses of rainbow trout (Salmo gairdneri), and backcrosses of coho salmon (Oncorhynchus kisutch). The two-three-, or four-banded phenotypes of homozygous individuals and all heterozygous and hybrid phenotypes of ten salmonid species are readily explained by the following model: (1) there are no detectable heterodimers either between allelic products at a single locus or between loci: (2) each allele is represented electrophoretically by two bands, presumably a reflection of stable posttranslational modification of a single polypeptide unit; (3) CK of salmonid muscle is encoded by two loci--CK-1 and CK-2. The distance separating the paired bands reflecting each allele provides a basis for two groupings--a broad-spaced group (including all species of Oncorhynchus tested excepting O.

Genetic variation, inheritance, and quaternary structure of malic enzyme in brook trout (Salvelinus fontinalis).

Electrophoretic variation is described for malic enzyme (ME) for the first time in brook trout (Salvelinus fontinalis). Since the quaternary structure of ME was not clear from examination of banding patterns in brook trout alone, ME phenotypes in rainbow trout (Salmo gairdneri)X brook trout hybrids as wel as in esocid species demonstrated that ME is tetrameric. A model of two duplicated loci is proposed to account for the observed variation.

Theophylline-7-acetic acid: lack of absorption and therapeutic effectiveness.

A double-blind cross-over trial was conducted to evaluate the effectiveness of oral theophylline-7-acetic acid (T7AA) in 13 asthmatic patients. Pulmonary function tests showed no difference between T7AA and placebo. No T7AA or theophylline was found in the sera of these patients or of healthy volunteers who took T7AA tablets or syrup.

Competency based education: general concepts.

Competency based education is a system of education which focuses on the performances to be exhibited by the graduates of the educational program. This paper presents an overview of the steps in the development of a competency based curriculum and gives examples which apply the concepts to a physical therapy educational program.

Competency based evaluation of student performance.

Criterion referenced evaluation instruments are used to determine student achievement in a competency based educational systems. The general concepts underlying competency based education and evaluation are described and the method used to implement these concepts in the Department of Physical Therapy of the Medical College of Georgia are outlined. Student performance is evaluated against external criteria and not against each other.

Proteinase-sensitive release of enzymes from pancreatic microsomal fraction.

Suspensions of rat pancreatic microsomal fraction release alpha-amylase and ribonuclease on incubation at 37 degrees C, but not at 2 degrees C. The release is abolished by proteolytic enzymes. Ribonuclease associated with the microsomal fraction is protected from subtilisin BPN' attack, but is sensitive after release.