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Biomedical subjects

N J King

Publications and source records attributed to N J King.

At least 19 recordsLinked to original sources
PubMed1992

An NMR investigation of the changes in plasma membrane triglyceride and phospholipid precursors during the activation of T-lymphocytes.

Two-dimensional 1H-NMR spectroscopy was used to quantify the level of isotropically tumbling plasma membrane triglyceride and the intracellular concentrations of water-soluble phospholipid precursors during the activation of thymic T-lymphocytes. The concentration of "mobile" triglyceride in the plasma membrane was seen to increase 25-fold during 72 h of activation of murine thymic T-lymphocytes with ionomycin and phorbol myristate acetate. This is the first unequivocal demonstration of such a dramatic increase in mobile plasma membrane triglyceride during T-lymphocyte activation and leads to the suggestion that immune cell activation is associated with increased plasma membrane fluidity. The intracellular concentrations of choline- and ethanolamine-based phospholipid precursors were shown to increase during the early stages of T-lymphocyte activation and then remain at levels above those in resting cells. This may facilitate de novo phospholipid biosynthesis, which is presumably necessary since cell volume, and hence the plasma membrane surface area, was demonstrated to increase significantly during thymocyte activation.

Animals↗
PubMed1992

Flavivirus induces MHC antigen on human myoblasts: a model of autoimmune myositis?

Infection of human embryonic myoblasts by West Nile virus (WNV), a flavivirus, caused significant upregulation of class I and II MHC expression as determined by flow cytometry. After 48 hours at a multiplicity of infection of 5 pfu/cell, a sixfold increase in MHC class I expression was induced from initially low levels of expression. In contrast, MHC class II was induced de novo to five times the control fluorescence level. At least 70% of the cells were infected as determined using fluorescence microscopy and anti-WNV antibody labeling. Myoblasts were > 90% pure as shown by anti--Leu-19 labeling. MHC class I (but not class II) was increased threefold after exposure to virus-inactivated supernatant from 48-hour--infected cells, indicating the presence of factor(s) contributing to the MHC class I increase. These findings may be important in establishing a link between viral infection of human cells and induction of inflammatory autoimmune disease. We discuss the possibility of using WNV as an in vivo model.

Autoimmune Diseases↗
PubMed1992

Manifest anxiety and fearfulness in children and adolescents.

The relationship between self-reported fear and anxiety was examined in a large sample of normal Australian children and adolescents. Participants completed the Fear Survey Schedule for Children--Revised (Ollendick, 1983) and the Revised Children's Manifest Anxiety Scale (Reynolds & Richmond, 1978). Following an examination of the internal consistency of these instruments, correlational analyses were conducted on anxiety and fear scores. Fear scores were shown to be sensitive to anxiety, sex, and age groups. Furthermore, discriminant analysis showed that high-anxiety children indicated a greater fear of items related to failure and criticism than did low-anxiety children. Other issues, including the content overlap between the two scales used in the investigation, are discussed.

Adolescent↗
PubMed1992

School refusal.

Explore the source record for details and available documents.

Adolescent↗
PubMed1992

Psychometric evaluation of a revised fear survey schedule for children and adolescents.

This study describes the second revision of a fear survey schedule for children which was originally developed by Scherer and Nakamura in the 1960's. The revised instrument (FSSC-II) was psychometrically evaluated on a sample of 918 children and adolescents aged between 7 and 18 years, attending regular primary and secondary schools in urban, suburban and rural areas of Victoria. It was demonstrated to have high internal consistency. The convergent and divergent validity of the revised instrument was examined by correlating it with conceptually related as well as distinct scales, respectively. Such analyses demonstrated sound validity. A five-factor solution almost identical to that reported for the FSSC-R, is described as are age and gender differences. The most common fears on the revised instrument are also reported.

Adolescent↗
PubMed1992

Treatment of childhood anxiety disorders using behaviour therapy and pharmacotherapy.

Although the treatment of childhood anxiety disorders can be approached from numerous theoretical perspectives, the concentration of research has been on the efficacy of behaviour therapy. Behaviour therapy procedures are briefly described and evaluated, including systematic desensitisation, flooding, modelling, reinforcement and cognitive procedures. We also review research findings on pharmacotherapy, focusing on benzodiazepine and antidepressant usage. Finally, several conclusions are drawn concerning the scientific and clinical status of these treatment approaches for childhood anxiety disorders.

Anti-Anxiety Agents↗
PubMed1991

Alloreactive cytotoxic T cells recognize MHC class I antigen without peptide specificity.

In this report, experiments are described to differentiate between three potential models of class I MHC allorecognition, namely 1) recognition of peptide-free MHC, 2) peptide-MHC-specific recognition, and 3) peptide-MHC-nonspecific recognition. Using a nucleoprotein peptide (NPP) with a sequence derived from influenza virus nucleoprotein with high affinity for Kd class I MHC molecules, it is shown that target cells rapidly become lysable by Kd-NPP self-restricted cytotoxic T (Tc) cells, and retain sufficient Kd-NPP complexes for at least 72 h. Kd-specific alloreactive Tc cells at the clonal and polyclonal level do not show decreased lysis of Kd-bearing targets in the continuous long term (48 h) presence of NPP. Kd-stimulator cells modified with NPP are able to induce potent Kd-NPP-specific self-restricted Tc cells, however Kd-NPP stimulator cells do not generate Kd-NPP specific alloreactive Tc cells from CBA and B10.A (5R) mouse strains as tested by limiting dilution split clone experiments. Human cells infected with the vaccinia virus recombinant coding for the murine Kd class I MHC Ag can be lysed by murine Kd-specific alloreactive Tc cells. In addition the rate of reemergence of alloreactive and self-restricted Tc cell epitopes on virally infected target cells that had their cell-surface class I MHC Ag removed is identical. These results are consistent with model 3 namely that the majority of Tc precursor and effector cells recognize class I MHC Ag without peptide specificity.

Animals↗
PubMed1991

Magnetic resonance studies of murine macrophages. Proliferation is not a prerequisite for acquisition of an 'activated' high resolution spectrum.

Proton magnetic resonance spectroscopy (1H-MRS) was used to investigate the membranes of macrophages activated by gamma-interferon in vitro and by Listeria monocytogenes in vivo. We report the appearance with activation, of a high resolution spectrum indistinguishable from that found in activated T and B cells and embryonic and malignant cell types previously studied. We furthermore show that proliferation is not a prerequisite for the appearance of this activated spectrum. This supports the idea that membrane 'activation' in all cells, irrespective of origin, may be accompanied by similar architectural changes, and suggests that a common pathway exists for the activation of cell membranes of the immune system, possibly important in the acquisition of increased motility. The use of 1H-MRS as a non-invasive tool for analysis of activation is discussed.

Animals↗
PubMed1991

Origins of childhood fears: an evaluation of Rachman's theory of fear acquisition.

This study explored Rachman's (1977) theory of fear acquisition in a large sample of Australian and American children and adolescents. Participants completed a questionnaire that addressed different pathways of fear acquisition for 10 highly prevalent fears. The majority of children attributed the onset of their fears to vicarious and instructional factors, although these indirect sources of fear were often combined with direct conditioning experiences. Also examined were effects for gender, age, and nationality. Boys and preadolescents were found to report more direct and vicarious experiences than girls or adolescents. Effects due to nationality were minimal. Methodological limitations attendant to self-reports were acknowledged.

Adolescent↗
PubMed1991

The effects of West Nile virus on major histocompatibility complex class I and II molecule expression by Lewis rat Schwann cells in vitro.

The expression of major histocompatibility complex (MHC) class I and II molecules by Lewis rat Schwann cells after infection with West Nile virus (WNV) in vitro was examined by fluorescence microscopy and flow cytometry. WNV enhanced the expression of MHC class I molecules and induced the expression of MHC class II molecules by Schwann cells. Irradiated medium from WNV-infected Schwann cell cultures upregulated class I molecule expression on dissociated Schwann cell cultures but did not induce the expression of class II molecules. This finding has implications for virally triggered autoimmune diseases of nervous tissue.

Animals↗
PubMed1991

Spermatic vein occlusion with hot contrast material: angiographic results.

Spermatic vein occlusion by means of selective injection of boiling contrast material into the spermatic vein was attempted in 175 men with symptomatic varicoceles or infertility. Seventy-six patients (43%) returned for follow-up venography. Of 115 veins injected, 96 (83%) were totally occluded on the follow-up venogram obtained at 6 weeks to 2 years after injection. In the latter portion of the study, the technique was changed slightly, with injection of larger volumes of hot contrast material, resulting in a 91% occlusion rate. Each vein that was found patent on the follow-up venogram (19 of 115 [16%]) was assessed radiographically, and results were categorized as grade 1, a complete failure in which there was no change from the presclerotherapy appearance (nine of 19 [47%]); grade 2, a failure in which the treated vein was smaller but patent (five of 19 [26%]); or grade 3, a failure in which the treated vein was occluded with newly developed collateral vessels (five of 19 [26%]). The pretreatment size of the spermatic vein and the quantity of hot contrast material injected were both statistically significant factors in the treatment outcome.

Adolescent↗
PubMed1991

Childhood obsessive-compulsive disorder.

Childhood OCD is a distressing and debilitating condition. Childhood OCD is not a simple exaggeration of the rituals and superstitions that occur over the course of normal development. More males than females are diagnosed as having OCD. Not unexpectedly, anxiety and affective disorders are often associated with childhood OCD. Compulsive personality disorder is also an associated feature for a proportion of children with OCD. Treatment usually involves individual psychotherapy and family counselling, although behavioural treatment and medication (clomipramine) have also been used by clinicians.

Adolescent↗
PubMed1991

Acceptability of alternative treatments for school refusal: evaluations by students, caregivers, and professionals.

School refusal is a debilitating condition that may be treated in various ways. This study examined the acceptability and perceived effectiveness of alternative treatments for school refusal. A total of 376 people comprising students, parents, and professionals, were required to evaluate several treatment options in relation to a vignette. Despite its potential aversiveness, behavioural management was the most acceptable treatment approach followed, in order, by home tuition with psychotherapy, hospitalisation, and medication. A strong positive relationship was found between acceptability and perceived effectiveness.

Adolescent↗
PubMed1990

Immunodeficient mice recover from infection with vaccinia virus expressing interferon-gamma.

Recombinant vaccinia viruses (VV)-encoding murine interferon-gamma (IFN-gamma) were constructed and the effect of virus-encoded IFN-gamma on the immune response towards VV in vivo investigated. In athymic nude mice and sublethally irradiated euthymic mice, IFN-gamma expression by VV enabled the mice to recover from the infection, whereas mice infected with the control virus died. In normal CBA/H mice also, the growth of VV was greatly reduced and it was cleared faster from mouse organs than the control virus. Natural killer (NK) cell responses in these mice were not enhanced suggesting that this recovery is not NK cell mediated. Other possible mechanisms and implications of this observation are discussed.

Animals↗