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Biomedical subjects

J Elliott

Publications and source records attributed to J Elliott.

At least 145 records · Page 8Linked to original sources
PubMed1996

Study of calcium homeostasis in feline hyperthyroidism.

Thirty cats with untreated hyperthyroidism were blood sampled and their calcium homeostatic mechanisms and renal function assessed. The results were compared with those obtained from 38 age-matched control cats. The hyperthyroid group of cats were found to have significantly lower blood ionised calcium and plasma creatinine concentrations and significantly higher plasma phosphate and parathyroid hormone concentrations. Hyperparathyroidism occurred in 77 per cent of hyperthyroid cats, with parathyroid hormone concentrations reaching up to 19 times the upper limit of the normal range. The aetiology, significance and reversibility of hyperparathyroidism in feline hyperthyroidism remains to be established but could have important implications for both bone strength and renal function.

Alanine Transaminase↗
PubMed1996

Locus of control in behaviourally disordered children.

It is widely held that behaviourally disordered children have greater difficulty than their peers in recognising a contingent relationship between their actions and subsequent outcomes (i.e., they have a relatively external locus of control) yet studies have not examined intra-group differences within this population. For this reason, this study explored the relationship between a number of specific behaviours and locus of control in 237 children with emotional and behavioural difficulties. Cluster analysis and nonmetric multidimensional scaling were employed to group locus of control items and behaviours in ways which might assist prediction. The findings indicated very little relationship between locus of control and behaviour. It is suggested that clinicians working with behaviourally disordered children should treat the claims for the construct's therapeutic importance with a degree of caution.

Adolescent↗
PubMed1996

The prevalence of major depressive disorder and low self-esteem in medical inpatients.

OBJECTIVE: To determine the prevalence of major depressive disorder in acutely ill medical inpatients, and the relationship of this to low self-esteem. METHOD: A total of 186 patients were interviewed 6 or 7 days following admission to detect the presence of DSM-IV major depressive disorder (MDD). Patients were assessed using a new brief psychiatric interview, the Silverstone Concise Assessment for Depression (SCAD), which has previously been validated for use in the physically ill. The cognitive function of the patients was measured, using the Mini-Mental State Examination (MMSE), with patients scoring less than 22 on the MMSE being excluded from the study. The patients' self-esteem was also assessed, using the Rosenberg self-esteem rating scale. The severity and type of the patients' medical illness, and the recognition of psychiatric illness by both nurses and physicians were also noted. RESULTS: The results showed that 18 patients (9.7%) were depressed. The depressed patients were significantly younger than the nondepressed patients (mean age 46.3 +/- 3.9 years versus 57.1 +/- 1.5 years, respectively) and were significantly more likely to be female (61% versus 44%, respectively). The depressed patients had a significantly lower self-esteem than the nondepressed patients, whose self-esteem was no different from the general population. However, the depressed patients were not more severely ill than the nondepressed patients. The results also demonstrated that both nurses and physicians were poor at recognizing the presence of major depression, with nurses recognizing 33% of cases compared to 22% for medical staff. CONCLUSIONS: The results from this study demonstrate that while there is an increase in the incidence of depression in medically ill patients, this is not as great as has been previously reported, and is not related to severity of illness. The results from this study, therefore, are in keeping with other recent findings which show that the prevalence rates for MDD in medical patients is between 5% to 10% rather than the previously accepted range of 20% to 40%.

Adjustment Disorders↗
PubMed1996

Nonpeptide endothelin receptor antagonists. VII: Binding characteristics of [3H]SB 209670, a novel nonpeptide antagonist of endothelin receptors.

The data presented in this manuscript describes the binding characteristics of [3H]SB 209670, a potent nonpeptide tritium-labeled endothelin (ET) receptor antagonist. The binding of this antagonist to cloned human ETA and ETB receptors was specific, saturable and of high affinity. The apparent dissociation constants were 0.20 and 1.0 nM for ETA and ETB receptors, respectively. The maximum binding was 4.7 and 22.5 pmol/mg protein for ETA and ETB receptors, respectively. Unlike [125]ET-1, the binding of [3H]SB 209670 was reversible. The half-times (T1/2) for dissociation of this ligand from ETA and ETB receptors were approximately 60 and 10 min, respectively. Competition binding studies using [3H]SB 209670 and unlabeled agonists ET-1, ET-3 and S6c indicated that these agonists displayed similar affinities for human ETB receptors, whereas with ETA receptors, ET-1 was approximately 50-fold and 1500-fold more potent than ET-3 and S6c, respectively. Of the peptide antagonists tested, BQ123 (ETA-selective peptide antagonist), displayed Ki values of 40 and > 2300 nM for ETA and ETB, whereas RES701 (ETB-selective antagonist) displayed Ki values of > 1600 and 81 nM for ETA and ETB receptors, respectively. The nonselective peptide antagonist, PD 142893, was approximately 2-fold more potent for ETA compared with ETB receptors. Similar observations were made with nonselective nonpeptide antagonists, Bosentan, (+/-) SB 209670, SB 209670, and (-) SB 209670. All these compounds were 2 to 10 times more potent for ETA than ETB receptors.

Animals↗
PubMed1995

A continuous high-resolution physical map spanning 17 megabases of the q12, q13.1, and q13.2 cytogenetic bands of human chromosome 19.

We report the construction of a high-resolution physical map of a 17-Mb region that encompasses the entire q12, q13.1, and q13.2 bands of human chromosome 19. The continuous map extends from a region approximately 400 kb centromeric of the D19S7 marker to the excision repair cross-complementing rodent repair deficiency complementation group 1 (ERCC1) locus. The ordered clone map has been obtained starting from a foundation of cosmid contigs assembled by automated fingerprinting and localized to the cytogenetic map by fluorescence in situ hybridization (FISH). Clonal continuity of the map has been achieved by binning and linking the premapped cosmid contigs by means of yeast artificial chromosomes (YACs). The map consists of a single contig composed of 169 YAC members (minimal spanning path of 18 YACs) linking 165 cosmid contigs. Eighty percent, or about 13.2 Mb of the entire region spanned by the map, has been resolved to the EcoRI restriction map level. Twenty-nine sequence-tagged sites associated with genetic markers or derived from FISH-mapped cosmids have been placed on the map. In addition to the ERCC1 gene area, the map includes the location of the creatine kinase muscle locus (CKM), imidazoledipetidase (PEPD), glucophosphate isomerase (GPI), myelin-associated glycoprotein (MAG), the apolipoprotein E and C (APOE and APOC) genes, and the ryanodine receptor (RYR1) gene. This type of map provides a source of continuously overlapping DNA segments at a level of resolution two orders of magnitude higher than that obtained using YACs alone. In addition, it provides ready-to-use reagents for detailed analyses at the gene level, FISH studies of chromosomal aberrations, and DNA sequencing.

Chromosome Mapping↗
PubMed1995

Polyoma virus pseudocapsids as efficient carriers of heterologous DNA into mammalian cells.

Polyoma virus VP1 pseudocapsids, generated from a recombinant baculovirus, have been successfully used to transfer exogenous DNA stably into rodent (rat-2) cells. To evaluate the efficiency and biological usefulness of this route for introducing heterologous DNA into cells, the gene for a transforming deletion mutant of the middle T antigen of polyoma virus, dl8 MT, was used initially. Whereas the amount of DNA packaged together with pseudocapsids was found to be variable (2-30%), even at low efficiency its transfer as biologically functional information was high. The dl8 MT gene was stably transferred and integrated in low copy numbers into the host chromosome. Transformed cell lines (derived from single foci) were shown to produce high levels of the corresponding mutant protein, which was active in an in vitro protein kinase assay. In comparisons with the calcium phosphate DNA coprecipitation procedure (or lipofectin route), the VP1 pseudocapsid approach was shown to have many advantages in terms of maintenance of DNA fidelity and increased efficiency of gene expression. This system was also assessed for its ability to transfer into and express the chloramphenicol acetyl transferase (CAT) gene in a human liver cell line. Here again, the assay for functional CAT expression showed the pseudocapsid transfer procedure to compare favorably with lipofectin transfer. In another transient assay, a low-level endogenously expressed gene, p43, was complexed with pseudocapsids and transferred into human embryo lung fibroblasts, thereby increasing the expression levels. The ease of production of VP1 pseudocapsids, coupled with their efficient transfer of biologically useful information, should make this route of gene delivery an attractive proposition for further exploration with regard to gene therapy.

Animals↗
PubMed1995

Evidence for lack of modulation of mu-opioid agonist action by delta-opioid agonists in the mouse vas deferens and guinea-pig ileum.

1. There is evidence from in vivo studies for an interaction of mu- and delta-opioid ligands. In the present work this concept has been investigated using the mouse vas deferens and guinea-pig ileum myenteric plexus-longitudinal preparations. 2. In field stimulated vasa deferentia of the mouse, co-administration of sub-effective concentrations of the delta-opioid agonist [D-Pen2,D-Pen5]enkephalin (DPDPE) and [Met5]- or [Leu5]enkephalin had no effect on the dose-response curves of the mu-agonists [D-Ala2,MePhe4, Gly-ol5]enkephalin (DAMGO) and morphine. Similarly, the delta-opioid agonists did not alter the potency of morphine and DAMGO when added at different times prior to the mu-opioid agonists, or when EC50 concentrations of delta-opioid ligands were co-administered. Compounds with preferred activity for the putative delta 1-(DPDPE) or delta 2-([D-Ala2,Glu4]deltorphin II (Delt II)) opioid receptors were ineffective in this respect. 3. The guinea-pig ileum contains delta-opioid receptors. No function of these receptors in mediating blockage of field-stimulated contractions was observed with ligands having affinity for the putative delta 1 or delta 2 subtypes nor were the agonists able to modulate responses to mu-opioid ligands in this tissue. 4. The results demonstrate the modulation of mu-opioid agonists by delta-opioid agonists does not occur in the isolated peripheral tissues examined. Thus the findings do not support the concept of a functional coupling of opioid receptors, though the results may be explained by differences between opioid systems in the brain and peripheral tissues examined.

Animals↗
PubMed1995

Characterisation of beta-adrenoceptors in equine digital veins: implications of the modes of vasodilatory action of isoxsuprine.

Isolated equine digital veins (EDVs) were used to study beta-adrenoceptor mediated vasodilation and to examine isoxsuprine's vasodilatory mechanism of action. When the blood vessel wall tension was raised with potassium chloride solution (KCl; 59 mmol/l), the order of vasodilator potency of beta-agonists was: isoprenaline > fenoterol > noradrenaline > dobutamine > isoxsuprine. The beta 2-selective adrenoceptor antagonist, ICI 118551 (1 nmol/l) caused a 6.74 and 6.65-fold parallel shift to the right in the dose response curves to fenoterol and noradrenaline respectively. Propranolol (10 nmol/l) inhibited the vasodilatory action of isoprenaline in a competitive manner (19.6 +/- 6.4-fold parallel shift to the right) but was much less effective as an inhibitor of isoxsuprine's vasodilatory action. Isoprenaline and fenoterol were just as effective as vasodilators when blood vessel wall tension was raised with KCl, the thromboxanemimetic U44069 (9, 11-dideoxy-9 alpha, 11 alpha-epoxymethano-prostaglandin F2 alpha; 30 nmol/l) or the alpha 1-adrenoceptor agonist, phenylephrine (0.3 mumol/l). In addition, fenoterol's relaxation of U44069-induced tone was competitively inhibited by the beta 2-selective adrenoceptor antagonist ICI 118551 (8.4 +/- 0.9-fold parallel shift to the right). By contrast, isoxsuprine was 81.9 times more potent as a vasorelaxant of phenylephrine-induced tone when compared with KCl-induced tone and proved completely ineffective as a vasodilator of U44069-induced tone. When dose response curves to alpha-adrenoceptor vasoconstrictor agonists were obtained in the presence of isoxsuprine (0.1 mumol/l), competitive antagonism occurred with methoxamine and noncompetitive antagonism with BHT-920. These data suggest EDVs possess beta 2-adrenoceptors mediating vasodilation. Isoxsuprine is an alpha 1-selective adrenoceptor antagonist but has very low potency and efficacy as a beta-adrenoceptor agonist in this functional bioassay. Indeed, much of the vasodilatory action of isoxsuprine may be due to a mechanism which does not involve beta-adrenoceptors.

Adrenergic beta-Agonists↗
PubMed1995

Identification of Streptococcus porcinus from human sources.

Streptococcus porcinus is normally associated with infections in swine. Cultures of this streptococcal species are rarely reported from human infections. In the past 10 years, we have identified 13 cultures of S. porcinus from human sources from persons living in the United States and Canada. Seven of the strains were identified in the past 15 months. Nine of the strains were of a single serogroup, provisionally called C1. In addition, nine of the strains were isolated from the genitourinary tract of reproductive-age female patients, some with delivery problems. S. porcinus strains could be identified by hemolytic, serologic, and physiologic characteristics. All strains were susceptible to penicillin, erythromycin, and other antimicrobial agents. Fifty-four percent of the strains were resistant to tetracycline. These findings suggest that we may be seeing a change in the flora of the genitourinary tract of humans. Whether these isolates are significant pathogens is unknown at this time.

Animals↗
PubMed1995

Evaluation of three disk tests for identification of enterococci, leuconostocs, and pediococci.

Simple rapid tests for presumptive identification of catalase-negative non-beta-hemolytic cocci (i.e., enterococci, leuconostocs, and pediococci) have not previously been available. Seven hundred thirty-four strains of aerobic and facultatively anaerobic, catalase-negative, non-beta-hemolytic gram-positive cocci were tested for susceptibility to vancomycin (Vans) by a screening procedure and production of leucine aminopeptidase (LAPase) and pyrrolidonylarylamidase (PYRase) in disk tests. Three unique patterns of activity in response to the three disks (30 micrograms of vancomycin, PYRase, and LAPase) can be used to presumptively identify the vancomycin-resistant (Vanr) enterococci (Vanr and PYRase and LAPase positive), leuconostocs (Vanr and PYRase and LAPase negative), and pediococci (Vanr, PYRase negative, and LAPase positive). The results indicate that, together with Gram stain characteristics and the catalase test, the vancomycin, LAPase, and PYRase disk tests can be used to presumptively identify Vanr strains of enterococci as well as Leuconostoc and Pediococcus strains from human infections.

Aminopeptidases↗