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Biomedical subjects

T E Smith

Publications and source records attributed to T E Smith.

At least 73 records · Page 4Linked to original sources
PubMed1991

Quantitation of uracil in rodent diet.

Feeding of high levels of uracil to laboratory rodents results in the formation of calculi in the lumen of the urinary bladder. This urolithiasis stimulates cellular proliferation in the bladder and has been used in studies of two-stage carcinogenesis. Quantitation of uracil in rodent diet was achieved by extraction from the diet with ammonium hydroxide. The extract was applied to a strong anion-exchange solid-phase extraction column. Uracil is not retained on this matrix which adsorbs the majority of contaminants in the extract. The uracil was quantitated by HPLC on an ODS microbore column (100 x 2 mm internal diameter) eluted at 0.5 ml/min with 200 mM KH2PO4, pH 3.5, at 30 degrees C. Three structurally related pyrimidine bases, cytosine, uracil, and thymine, showed increasing retention on this column/solvent combination, thereby demonstrating selectivity of the analysis. Recovery of uracil was 76-90% with lower values observed when dietary levels of uracil were in excess of 4.5%.

Animal Feed↗
PubMed1991

Transgenic production of a variant of human tissue-type plasminogen activator in goat milk: generation of transgenic goats and analysis of expression.

We report the first successful production of transgenic goats that express a heterologous protein in their milk. The production of a glycosylation variant of human tPA (LAtPA--longer acting tissue plasminogen activator) from an expression vector containing the murine whey acid promoter (WAP) operatively linked to the cDNA of a modified version of human tPA was examined in transgenic dairy goats. Two transgenic goats were identified from 29 animals born. The first animal, a female, was mated and allowed to carry the pregnancy to term. Milk was obtained upon parturition and was shown to contain enzymatically active LAtPA at a concentration of 3 micrograms/ml.

Animals↗
PubMed1991

Lie to me no more: believable stories and marital affairs.

This case study illustrates the dilemmas of systemic practice when the presenting problem is relational infidelity (marital affairs). After several months of treatment with a structural therapist, the couple and therapist were at an impasse because of arguments over the husband's alleged sexual encounter 3 years previously. The introduction of a consultant and a story-based therapy allowed the couple to reconcile their marital difficulties. The article ends with a discussion of the implications of systemic paradigms and personal morality.

Attitude of Health Personnel↗
PubMed1987

Innervation of the pineal gland in the rat: an HRP study.

Injections of horseradish peroxidase were made stereotaxically and directly (surgically exposed) into the pineal gland of Sprague-Dawley and Long-Evans rats weighing 30 to 500 g (20 to 130 days of age). Retrogradely labeled cells were seen in the superior cervical ganglia. Anterogradely labeled fibers were observed within the pineal stalk, lamina intercalaris, and the medial habenular nuclei. Terminal fields were identified in lamina intercalaris and medial habenular nuclei. Labeled cells were not seen within the central nervous system. These results suggest that in the rat the pineal gland is not centrally innervated but in fact is innervated solely by the sympathetic postganglionic fibers.

Animals↗
PubMed1987

Sympathetic projections to the epithalamus.

Injections of horseradish peroxidase were made into surgically exposed superior cervical ganglia of Sprague-Dawley rats weighing 250 to 320 g. Anterogradely labeled postganglionic fibers were observed in the nervus conarii, pineal gland, pineal stalk, and the choroid plexus. Terminal fields were identified in lamina intercalaris and the medial habenular nuclei. These findings support a previous study indicating that the sole innervation of the pineal gland is via the postganglionic sympathetics.

Adrenergic Fibers↗
PubMed1987

Intravenous and intragastric self-administration of chlordiazepoxide in the rat.

Rats were implanted with intravenous (IV) or intragastric (IG) cannulas and allowed access, by lever-pressing on a CRF schedule, to chlordiazepoxide solution in 10-h sessions at doses of 0.1, 0.25, 0.5 and 1.0 mg/kg/injection. Self-administration behavior was acquired by both routes and for all doses of the drug by 60-70% of subjects tested. Subjects given access by the IV route showed more pronounced responding at the lower 2 doses and greater drug intake with the higher 2 doses than the IG group. A 2-lever study, controlling for possible motor effects of chlordiazepoxide, supports the interpretation that responding was indeed the result of reinforcing effects of chlordiazepoxide rather than an artifact.

Animals↗
PubMed1986

Isolation of the structural gene encoding a mutant form of Escherichia coli phosphoenolpyruvate carboxylase deficient in regulation by fructose 1,6-bisphosphate. Identification of an amino acid substitution in the mutant.

The structural gene encoding a mutant Escherichia coli phosphoenolpyruvate carboxylase deficient in regulation by fructose 1,6-bisphosphate (Fru-P2) was isolated from total E. coli PpcI genomic DNA. This mutant gene is located on a 4.4-kilobase SalI DNA fragment which, when ligated to SalI-digested pBR322, resulted in the generation of the plasmid pFS16. Detailed restriction mapping of the wild-type and mutant genes for phosphoenolpyruvate carboxylase revealed the presence of a ClaI restriction site at position 563 of the mutant gene only. This ClaI site is located on a 289 PvuII/DdeI fragment which codes for amino acid residues 174-270 of the phosphoenolpyruvate carboxylase enzyme. When this portion of the mutant gene is present in chimeras of the wild-type and mutant genes, the phosphoenolpyruvate carboxylase produced cannot be activated by Fru-P2. The mutation resulting in the generation of the ClaI site in the mutant gene has also resulted in an amino acid substitution at residue 188; threonine in the wild-type enzyme has been replaced by isoleucine in the mutant enzyme. Comparison of the nucleotide sequence of this 289-base pair PvuII/DdeI region of the mutant gene with its homologous region in the wild-type gene verified that this mutation, which resulted in the generation of the ClaI site, is the only change that has occurred on this 289-base pair fragment of the mutant gene, and thus the amino acid replacement of threonine by isoleucine is the only change that could be linked to the inability of the mutant enzyme to be activated by Fru-P2.

Amino Acid Sequence↗
PubMed1985

Properties of an Escherichia coli mutant deficient in phosphoenolpyruvate carboxylase catalytic activity.

A mutant Escherichia coli (Ppcc-) which was unable to grow on glucose as a sole carbon source was isolated. This mutant had very low levels of phosphoenolpyruvate carboxylase activity (approximately 5% of the wild type). Goat immunoglobulin G prepared against wild-type phosphoenolypyruvate carboxylase cross-reacted with the Ppcc- enzyme. The amount of enzyme protein in the mutant cells was similar to that found in wild-type cells, but it had greatly diminished specific activity. The catalytically less active mutant enzyme retained the ability to interact with fructose 1,6-bisphosphate, but did not exhibit stabilization of the tetrameric form by aspartate. The pI of the mutant protein was lower (4.9) than that of the wild-type protein (5.1). After electrophoresis and immunoblotting of the partially purified protein, several immunostaining bands were seen in addition to the main enzyme band. A novel method for showing that these bands represented proteolytic fragments of phosphoenolpyruvate carboxylase was developed.

Antibodies, Bacterial↗
PubMed1985

Ecology of adolescents' marijuana abuse.

Sixteen adolescent marijuana abusers reported data on the ecology of their use over a 3-month period. Abusers recorded data on the day, date, time, place, frequency, and amount of use. They also included information on their mood and functioning, and with whom they used marijuana. Peak use occurred just prior to school, at lunch, and in the early evening. Adolescents' homes, friends' houses, school, and cars represented 67% of locations in which marijuana was used. Happy, relaxed, and tired comprised 81% of moods experienced during time of use. Average core network was 5.8 individuals while casual networks averaged 15.5 adolescents. Presence of others during use was associated with abusers' increased use and decreased functioning.

Adolescent↗
PubMed1983

Reducing adolescents' marihuana abuse.

Marihuana abuse is defined, and a model for a drug education program for abusers is presented. The program's rationale is that abusers should be taught responsible use as an approximation for an ultimate goal of abstinence. The program model is based on an interpersonal-skills training approach to clinical problems and has three components: facts about marihuana, problem-solving abilities, and interpersonal skills to enact decisions. The program teaches participants to become aware of and enact choices that have the greatest likelihood of avoiding marihuana abuse.

Adolescent↗
PubMed1982

Cervicofacial high-pressure hydraulic injection injury. Report of a case.

High-pressure petroleum injection injuries and best known in the distal part of the upper extremity. A recent Medlars search revealed several articles dealing with this type of injury in the hands and wrists, but, as yet, there have been no publications of this type of trauma to the head and neck region. A 35-year-old farmer sustained a high-pressure petroleum injection injury to the lower part of the left cheek and neck. This case might serve as a guide for management of similar cases in the future.

Abscess↗