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Biomedical subjects

S Taylor

Publications and source records attributed to S Taylor.

At least 397 records · Page 22Linked to original sources
PubMed1985

Behavioral and neurochemical effect of daily injection with neurotensin into the ventral tegmental area.

Many lines of evidence indicate an excitatory role by neurotensin (NT) on mesolimbic dopamine neurons in the ventral tegmental area (VTA). In support of this postulate, NT microinjection into the VTA of rats produces a dopamine-dependent increase in spontaneous motor activity that is associated with an increase in dopamine metabolism in the nucleus accumbens. In this study it was found that after daily intra-VTA injection with NT, both the motor hyperactivity and increase in dopamine metabolism were significantly enhanced. Further, the increased motor response to NT was present after 7 days without daily administration. While the augmented motor response could be produced with the carboxy-terminal fragment NT8-13, the NH2-terminal fragment, NT1-8, was ineffective. The enhancement of motor activity was only produced by NT injection into the A10 dopamine region and not adjacent nuclei. These results suggest that daily administration with NT into the VTA will potentiate the responsiveness of mesolimbic dopamine neurons to subsequent injection with NT.

Animals↗
PubMed1985

Yersinia enterocolitica infection in children.

The role of Yersinia enterocolitica as a human pathogen has been documented in publications from over 30 countries, and Y. enterocolitica has been recognized increasingly to cause gastrointestinal disease in children. In 1979, an Australian survey yielded only three isolates of Y. enterocolitica from 3298 faecal specimens obtained from adults. We screened all stool specimens received during a 22-month period for Yersinia by means of a recently developed selective agar medium. Y. enterocolitica was isolated from 32 of 4136 (0.7%) specimens. Most isolates were of serotype O:3, biotype 4. During the study, 154 Salmonella spp. (3.7%), 196 Campylobacter spp. (47%), seven Shigella spp. (0.2%) and 27 Aeromonas spp. (0.9% of 2779) were recovered. Children infected with Y. enterocolitica presented with acute diarrhoea associated with fever and pharyngitis; chronic or recurrent diarrhoea; or pain in the right iliac fossa associated with mesenteric adenitis. Gastrointestinal symptoms usually resolved spontaneously within two weeks. However, some children were treated successfully with cotrimoxazole.

Adolescent↗
PubMed1985

Primary structures of the catalytic subunits from two molecular forms of acetylcholinesterase. A comparison of NH2-terminal and active center sequences.

Two distinct classes of acetylcholinesterase exist in near equal amounts in the electric organ of Torpedo californica. A globular 5.6 S form is a dimer which possesses a hydrophobic region. The second form is present as elongated species that sediment at 17 and 13 S and contain structural subunits disulfide-linked to the catalytic subunits. Removal of the structural subunits by mild proteolysis yields a tetramer of catalytic subunits which sediments at 11 S. To compare the primary structures of the catalytic subunits of the 5.6 S and 11 S forms of acetylcholinesterase, amino acid sequences from the active sites and from the amino-terminal regions have been elucidated. Active site serines were labeled with [3H]isopropyl fluorophosphate. After digestion with trypsin, the resultant peptides were resolved by elution from a size-exclusion column followed by reverse-phase high performance liquid chromatography. Each active site tryptic peptide contained 24 residues and identical sequences were found in this peptide for the 5.6 S and 11 S forms of the enzyme. The sequence flanking the active site serine revealed extensive homology with the published sequence of human serum cholinesterase as well as a lesser degree of homology with other known serine proteases and esterases. The sequences of the amino-terminal region also appear to be identical for both enzyme forms although we note variation in the ratio of Glu and Gln at position 5. The amino-terminal sequence exhibits only partial homology with the published sequence of human serum cholinesterase.

Acetylcholinesterase↗
PubMed1985

Phase I evaluation of chlorozotocin (NSC-178248): weekly schedule.

A phase I trial of chlorozotocin was completed for a weekly times four dose schedule repeated every 8 weeks. Thrombocytopenia was the acute dose limiting toxicity. Nausea and vomiting were moderate to severe and dose related. Two cases of possible drug related irreversible nephrotoxicity were seen. Transient elevations of serum creatinine and mild proteinuria were noted. Also, transient elevations in SGOT were observed. One patient with a carcinoid tumor had a 60% reduction in his 5HIAA level after one course of therapy. The recommended dose for phase II clinical studies of chlorozotocin is 40 mg/m2 IV weekly for four weeks, repeated every 8 weeks.

Adult↗
PubMed1985

Percutaneous fine needle biopsy in pediatrics.

We performed 25 percutaneous fine needle biopsies (PFNB) on pediatric patients during a 3-year period. Of 17 patients with proven malignancies, PFNB was true positive in 16 and false negative in one. In nine patients with benign or inflammatory disorders, there were three true positives and six false negatives. There were no complications either from PFNB or larger caliber core biopsies, which were also performed in selected cases. All procedures were performed with ultrasound and/or fluoroscopic guidance. General anesthesia was not required, except in cases where PFNB was performed together with a surgical procedure. PFNB is as accurate and safe in pediatric patients as in adults. It should be considered prior to any open surgical procedure performed for biopsy alone.

Adolescent↗
PubMed1985

The effects of marijuana on human physical aggression.

Thirty male undergraduates received intense provocation following their ingestion of one of three doses of delta-9-tetrahydrocannabinol (THC). The subjects in the low-dose condition tended to respond in a more aggressive manner than the subjects in the moderate-and high-dose conditions. The subjects in the high-dose condition behaved in a relatively nonaggressive manner throughout the experimental session.

Adolescent↗
PubMed1985

Glucocorticoid receptors in Epstein-Barr virus-transformed human lymphocytes.

Glucocorticoid receptors were studied in cultured human lymphocytes from normal donors after transformation with the Epstein-Barr Virus (EBV) and compared to those of circulating human mononuclear leukocytes. Both whole cell and cytosol fractions were examined for [3H]-dexamethasone binding. The concentration and absolute number of glucocorticoid binding sites were increased five-fold in the transformed cells when compared to the non-transformed human mononuclear leukocytes. However, the affinity (Kd) of the glucocorticoid receptor for dexamethasone was the same in both types of cells. The denatured glucocorticoid receptor, covalently labelled with [3H]-dexamethasone-21-mesylate, was identified by SDS polyacrylamide gel electrophoresis as a protein moiety with Mr approximately equal to 92,000, similar to that obtained from human non-transformed mononuclear leukocytes. The pattern of the activation of the hormone-receptor complexes, analyzed by phosphocellulose chromatography, was similar in both types of cells, and also the time-courses of loss of specific binding during thermal activation were similar. These results suggest that viral transformation is associated with increases in the concentration and the absolute number of glucocorticoid receptors whereas other qualitative receptor characteristics remain similar. Thus, transformation of cells with EB virus can provide a constant source of glucocorticoid receptors for study.

B-Lymphocytes↗
PubMed1985

Inhibition of the Mg(II).ATP-dependent phosphoprotein phosphatase by the regulatory subunit of cAMP-dependent protein kinase.

We report potent inhibition of the Mg(II).ATP-dependent protein phosphatase, Fc.M, by the regulatory subunit dimer of type II cAMP-dependent protein kinase, RII2. The protein kinase catalytic subunit has no effect on phosphatase activity and is unable to substitute for kinase FA in the kinase FA- and Mg(II).ATP-mediated phosphatase activation reaction. Phosphatase inhibition was investigated as a function of RII2 concentration. The results suggest that RII2 both inhibits the active phosphatase and inhibits phosphatase activation. The inhibition is shown to be noncompetitive with respect to substrate (phosphorylase a). The potential physiological significance of this inhibition is discussed in terms of phosphorylation/dephosphorylation cascade systems involving this kinase and phosphatase.

Adenosine Triphosphate↗
PubMed1985

Male violence toward females: victim and aggressor variables.

The present study focused on the effects of two variables that have been proposed as determinants of male violence toward female targets in American society. One target variable, verbal attack, and one aggressor variable, masculine performance, were manipulated. Forty male research participants competed in a reaction-time task with a female confederate who had previously criticized them or remained silent when the males' performance on a physical strength task appeared to be average or considerably below the norms for male performance. The significant interaction between the two variables indicated that inhibitions against harming females were reduced when the male performed poorly on a masculine task in the presence of a female who criticized his performance. Results are discussed in terms of their relevance to control and understanding of male-to-female aggression in the natural ecology.

Achievement↗
PubMed1985

Sensitive system for visualising biotinylated DNA probes hybridised in situ: rapid sex determination of intact cells.

A fast and sensitive method for detecting biotinylated deoxyribonucleic acid (DNA) probes was used for sex determination of cells and tissues by in situ hybridisation of a probe "specific" for the Y chromosome (pHY 2.1). Within 24 hours this procedure visualizes the Y chromosome in fetal and adult cells and tissue, without background noise. This procedure should facilitate antenatal determination of sex on small numbers of uncultured cells. The sensitivity of the procedure also permits the chromosomal assignment of genes present in low copy number.

Adult↗
PubMed1985

Sensitization to repeated enkephalin administration into the ventral tegmental area of the rat. I. Behavioral characterization.

Acute injection with the enkephalin analog, D-Ala2-Met5-enkephalinamide (DALA), into the ventral tegmental area (VTA) of the rat will elicit behavioral hyperactivity. In this study it was found that daily intra-VTA injection with DALA results in a progressively enhanced motor response. The augmented behavioral response was dose-related, occurring at a threshold dose between 0.3 and 1.0 microgram of DALA per side. It consisted of a significant increase in locomotion and bursting, and a decrease in the occurrence of sleep/still. The augmented motor response did not result from decreased elimination of microinjected DALA from the VTA. Naloxone blocked the development of an enhanced motor response, as did substitution with the putative kappa opioid agonist, dynorphin. However, the sensitization to DALA was retained when the delta opioid agonist, D-Ala2-D-Leu5-enkephalin, was substituted for DALA and partial sensitization occurred when the mu opioid agonist, morphine, was substituted for DALA. Conditioning to the behavioral apparatus was not found to play a role in the sensitization to DALA. These data demonstrate that daily exposure of neurons in the VTA to enkephalin analogs results in a semipermanent alteration in the response of these neurons to subsequent injections with enkephalin analogs.

Animals↗
PubMed1985

Impaired production of gamma-interferon by newborn cells in vitro is due to a functionally immature macrophage.

The decreased production of gamma-(PHA-induced) interferon (IFN) by leukocytes of normal newborns could be due to functionally immature T cells, macrophages, or both. We studied gamma-IFN production by macrophages and T cells, alone and in combination, obtained from 50 cord blood samples and 14 adult blood samples in a series of experiments. Adherent macrophages were cultivated for 7 days before the addition of T cells. After 48 hr, PHA-stimulated macrophage-T cell supernatants were harvested and assayed for IFN by a microassay. Macrophage-T cell cultures of autologous and nonautologous cells in 14 adults showed enhanced IFN production (GMT 121 +/- 5 IU) as compared with Ficoll-Hypaque mononuclear cells (GMT 42 +/- 5 IU). No IFN was detected in supernatants from PHA-stimulated Ficoll-Hypaque cord cells alone or macrophage-T cord combined cultures. Combined cord macrophages and adult T cells produced minimal IFN (GMT 13 +/- 3 IU); however, cord T cells combined with adult macrophages showed enhanced IFN production (GMT 195 +/- 47 IU). This cord macrophage dysfunction was not due to an inhibitor and improved with the time of in vitro cultivation. These results indicate that the neonatal macrophage is primarily responsible for the impaired gamma-IFN response by the newborn cells.

Adult↗
PubMed1984

Bicycles.

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Community Health Nursing↗
PubMed1984

Combination chemotherapy plus levamisole in the treatment of disseminated malignant melanoma. A Southwest Oncology Group study.

Two hundred-eighty patients were randomized to receive either BCNU, hydroxyurea and imidazole carboxamide (BHD), BHD plus levamisole, or high-dose DTIC plus actinomycin D. There was no difference in response rate in the three groups (24%, 25% and 22%). Females responded better than males and, as expected, those with a better performance status responded more favorably than those with poor performance status. Patients whose primary site of melanoma was on the extremities did significantly better than those melanomas originating on the trunk or head and neck. Patients with lymphocyte counts greater than 2000/mm3 fared better than those with lymphopenia. Those responders who received high-dose DTIC plus actinomycin D had a significantly longer length of response than those receiving the immunotherapy limb. This was also true in those patients who had a prior disease-free interval of greater than 6 months before being placed in this study. Although there was no difference in survival from the start of treatment in all patients, those patients receiving high-dose DTIC plus actinomycin D and who had a prior disease-free interval of greater than 6 months, had significantly superior survival when compared to the immunotherapy limb. It is concluded that the addition of Levamisole to BHD does not improve response rate and may in certain subsets be detrimental to disease-free response and survival. High-dose DTIC plus actinomycin D is equally effective to BHD.

Antineoplastic Combined Chemotherapy Protocols↗