Search PubMed⌕ Search

Biomedical subjects

C Hale

Publications and source records attributed to C Hale.

At least 19 recordsLinked to original sources
PubMed1992

Modulation of tyrosine hydroxylase gene expression in the rat adrenal gland by exercise: effects of age.

Both aging and exercise are associated with alterations in circulating levels of catecholamines. To determine the interactions of age and exercise on tyrosine hydroxylase (TH) activity and TH mRNA, Fischer-344 female rats aged 5 months (young) and 25 months (old) were trained by treadmill running for 10 weeks. The elevation in maximum oxygen consumption in both groups was equivalent following exercise, indicating that training had occurred. In control rats, both TH activity and TH mRNA were greater in the older groups when compared with the younger animals. In young rats, exercise decreased TH activity by 25% and TH mRNA by 27%. In older rats, exercise was not associated with a decrease in TH activity and TH mRNA. Choline acetyltransferase activity (ChAT) was decreased and glutamic acid decarboxylase activity (GAD) was increased by exercise in young rats. The decrease in ChAT activity and increase in GAD activity suggest that trans-synaptic mechanisms play a role in the exercise-induced alteration of TH gene expression. Neither ChAT nor GAD was altered by exercise in older groups. Our data suggest that the previously reported diminution in catecholamines associated with exercise may be due to a decrease in TH mRNA and a resulting decrease in TH activity. There was no effect of exercise in the old rats, supporting previous observations that the plasticity of the sympathoadrenal system diminishes with age.

Acetylcholine↗
PubMed1992

The educational antecedents of teen fatherhood.

In attempting to identify the determinants of teen pregnancy, researchers have focused on risk factors for young women, largely ignoring teen fathers. This study examines the educational antecedents of teen fatherhood using the 1958 National Child Development Study. Results suggest that those less than 20 years old at onset of fatherhood are much more likely than those who had not fathered a child by age 23 to have experienced academic difficulties and that such difficulties antedate teen fatherhood by as much as a decade. Variables measuring parents' lack of interest in their sons' education were strongly associated with the risk of teen fatherhood as were teachers' negative assessment of boys' academic ability, and the boys' own desire to terminate education as early as possible. Social class was modestly important in explaining differences in educational experiences for teen fathers and non-fathers.

Adolescent↗
PubMed1991

Degeneration of the cholinergic innervation of the locus ceruleus in Alzheimer's disease.

Choline acetyltransferase (Acetyl-CoA: choline O-acetyltransferase: EC 2.3.1.6) (ChAT) enzyme activity and neuron density were measured in the locus ceruleus (LC) of autopsied brains of neurologically normal individuals and patients who had Alzheimer's disease. Neuron density in the LC of individuals with Alzheimer's was significantly reduced to approximately 50% of normal values. ChAT activity was also reduced by about 50%. Furthermore, the number of pigmented neurons in the LC was highly correlated with presynaptic ChAT activity. These findings were specific for the LC, since deficits in ChAT and neuron density were not found in two adrenergic brainstem nuclei (C1 and C2). We measured mitogen activity in LC extracts in order to determine whether loss of cholinergic afferents to the LC, as evidenced by loss of ChAT, was related to putative trophic factors. Mitogen activity was significantly reduced (50%) in the Alzheimer's group as compared to normals. Mitogen activity was significantly correlated with ChAT activity and the density of neurons in the LC. The loss of cholinergic nerve terminals in the LC in Alzheimer's disease may be functionally significant, since acetylcholine has important effects on LC physiology. The highly significant relationships between ChAT, neuron density and mitogen activity has important implications for our understanding of mechanisms of neurodegeneration in Alzheimer's disease.

Aged↗
PubMed1991

Evaluating a change to primary nursing: some methodological issues.

The purpose of this article is to review the work which has been carried out to evaluate the introduction of primary nursing and to highlight some of the methodological issues arising from research in this area. The author begins by considering the research design and outcome variables which have been frequently used in evaluative studies of primary nursing and then develops alternative explanations for the results which the researchers obtained.

Clinical Nursing Research↗
PubMed1990

GABA receptor modulation of tyrosine hydroxylase gene expression in the rat adrenal gland.

Chromaffin cell gamma-aminobutyric acid (GABA) receptors play a role in modulating catecholamine secretion. The present experiments examined the role of GABA receptors in modulation of tyrosine hydroxylase (TH) induction in rat adrenal gland. Administration of bicuculline, a GABA antagonist, had no effect on TH activity or TH mRNA. However, bicuculline potentiated reserpine's effect on TH activity and TH mRNA induction. These data suggest that GABA receptors modulate induction of TH and TH mRNA in the adrenal gland.

Adrenal Glands↗
PubMed1990

Modulation of tyrosine hydroxylase gene expression in the rat adrenal gland by age and reserpine.

Tyrosine hydroxylase (TH), TH messenger RNA (TH mRNA) and dopamine (DA) were measured simultaneously in adrenal glands of individual Fischer 344 rats aged 2, 6, 13 and 23 months. Between 2 and 23 months TH activity rose 2-fold as compared to the youngest group. TH mRNA content of the adrenal gland rose 3-fold between 2 and 23 months. A 3-fold increase in adrenal DA content, the first catecholamine product of TH, provides evidence that the increases in TH gene expression are functionally significant. To determine if mechanisms that regulate gene expression are altered by aging, the effects of reserpine on induction of TH mRNA and TH activity were compared in another group of rats aged 2, 12 and 27 months. Consistent with the results of the first experiment, there were age-related increases in both TH activity and TH mRNA in the age-matched control groups. TH activity rose 2-fold and TH mRNA rose more than 6-fold between 2 and 27 months. The discrepancy in the relative magnitudes of increases in TH mRNA and TH protein suggest an uncoupling of regulation of TH mRNA and TH protein levels. Moreover, there were significant age-related differences with respect to modulation of TH gene expression by reserpine treatment. TH activity was induced by reserpine in the youngest group, but not in the two older age-groups. In contrast, reserpine caused significant induction of TH mRNA in all age groups. These results provide evidence that aging is accompanied by alterations in transcriptional and post-transcriptional mechanisms involved in regulation of TH gene expression.

Adrenal Glands↗
PubMed1989

Use of seclusion in a psychiatric intensive care unit.

OBJECTIVE: To evaluate the use in a psychiatric intensive care unit of a newly introduced seclusion room for the management of acutely disturbed and/or violent patients. METHOD: A specially designed seclusion chart was used to document fully events immediately before, during, and immediately after seclusion. Data from the charts over a 6-month period provided the basis for the study. RESULTS: The seclusion rate of about 2% of all admissions is less than that reported in the UK and the USA, suggesting that the facility is not used exclusively. Nursing staff welcomed seclusion as a means of reducing levels of dangerousness in the unit, but emphasized that it should be monitored carefully in order to prevent inappropriate use.

Clinical Protocols↗
PubMed1979

Characteristics of the T-dependent alpha(1 leads to 6) glucosyl (dextran) antibody response induced in mice with isomaltohexaose coupled to chicken gamma-globulin.

Isomaltohexaose flavazole coupled to chicken gamma-globulin (IM6-CGG) induced T cell-dependent anti-alpha(1 leads to 6) dextran-specific IgM and IgG responses in CBA, BALB/c and A strain mice. The IgG responses were of restricted heterogeneity as judged by isoelectric focusing, and belonged mostly to the IgG1 subclass with a minor IgG3 component in the case of BALB/c and CBA mice. All four subclasses of IgG were produced in A strain mice. In contrast, native dextran B 512 induces exclusively T cell-independent IgM responses of the same specificity for all 3 strains. All BALB/c mice immunized with different doses of IM6-CGG either in Freund's adjuvant or with Al(OH)3 plus Bordetella pertussis showed the same spectrotypes by isoelectric focusing. Sera obtained at different times after immunization of BALB/c mice failed to show spectrotype variations. Late, but not early, bleedings from CBA mice showed a tendency towards more uniform isoelectric focusing patterns.

Animals↗
PubMed1978

Tardive dyskinesia and antihistamines.

A case of tardive dyskinesia due to the prolonged administration of antihistamines is reported. Clinical features are discussed, as well as the alleviation of these by haloperidol.

Dyskinesia, Drug-Induced↗
PubMed1976

Lack of neonatal susceptibility to induction of tolerance by polysaccharide antigens.

Susceptibility to tolerance induction by polysaccharides during the neonatal period has been studied with the alpha-1.3 and alpha-1.6 glucosyl epitopes of dextran B1355 in BALB/c mice and the beta-2.6 fructosyl epitope of levan in CBA mice. Acquisition of responsiveness, as measured by plaque-forming cell (PFC) assays, is relatively late - taking more than 14 days to appear and 2 - 3 months to attain maturity in the case of alpha-1.6 glucosyl and beta-2.6 fructosy. The mice responded well to sheep red blood cells and 2,4-dinitrophenylated (DNP) keyhole limpet hemocyanin (KLH) by 14 days, but were refractory to another thymus-independent antigen DNP-Ficoll. Nonresponsiveness of 2-week-old spleen cells to the polysaccharides was stable on transfer and could not be attributed to suppressor cells. Despite this long post-natal phase of immaturity, no evidence was obtained of concomitant susceptibility to tolerance induction by textran and levan. Response curves in mice injected at birth with weight-adjusted doses revealed similar or even higher "high-zone" thresholds to those tolerized at 3 months. Only partial alpha-1.3 glucosyl tolerance is inducible in adults but this was no greater after neonatal exposure, which led also to short-lived alpha-1.6 tolerance. Repeated injections of B1355 and levan during the first 10 days was no more tolerogenic and PFC appeared spontaneously with maturity in mice given these antigens neonatally. Thus, the recognized neonatal susceptibility to thymus-dependent antigens does not extend to these thymus-independent antigens. It is therefore considered that tolerance studied with polysaccharides has little relevance to the mechanism of self-tolerance acquired in the embryo and, in vivo, is determined by interaction with a relatively mature B cell rather than by "clonal abortion" of a tolerance-sensitive precursor stage.

Age Factors↗
PubMed1976

Blockade of specific antibody-forming cells in vivo by dextrans and levans.

Fractions of dextrian (DE) B512, DE B1355 and levan (LE) have been shown to induce a specific blockade of antibody-forming cells (AFC) when injected into previously immunized mice. Whereas specific blockade with DE B512 (450 000 daltons) was easily induced by as little as 10 mug, blockade to LE and DE B1355 was more resistant and required 1 and 10 mg, respectively. AFC blockade and tolerance are dissociable phenomena, as the former effect could be achieved with nontolerogenic low mol. wt DE B512 (10 000 daltons). Conversely, perennial rye grass fructosan (7600 daltons), which is tolerogenic for LE, did not induce a blockade. Furthermore, blockade of anti-DE response specific for alpha (1 leads to 3)-linked glucosyl determinants was achieved in BALB/c mice, whereas attempts to induce stable tolerance have been unsuccessful.

Animals↗
PubMed1976

Lack of effect of thymectomy on spontaneous recovery from tolerance to levan.

Adult CBA mice were made tolerant with 1 mg levan and tested subsequently for sponteneous recovery by plaque-forming cell assay in response to immunizing challenge. Weakening of tolerance was first detectable only after 100 days, while return to full normal responsiveness required 400 days. Thymectomy 2 weeks prior to tolerization neither retarded nor diminished the recovery process. Loss of tolerance which had been induced by 1 mg dextran B512 was much slower in onset (greater than 250 days), yet not delayed by thymectomy (full recovery was not followed). These findings in relation to other considerations imply that associative recognition by T cells is not required for B cell responses to these "thymus-independent" antigens.

Animals↗
PubMedDate not supplied

Developing the new practitioner.

In the second part of this series on issues in ward management facing charge nurses, Claire Hale examines the role of the charge nurse in relation to three areas which are fundamental to Project 2000: the supernumerary status of students, the linking of theory to practice and the provision of a suitable learning environment. With the success or otherwise of the new courses depending to such a large extent on the enthusiasm and co-operation of charge nurses, the author suggests a number of tangible 'rewards' which may be offered in recognition of their efforts.

Education, Nursing↗