Biomedical subjects

K Harrison

Publications and source records attributed to K Harrison.

At least 37 records · Page 2Linked to original sources

PubMed1999

EEG theta activity and pain insensitivity in self-injurious borderline patients.

The principal aim of this study was to investigate possible neurophysiological underpinnings of self-injurious behavior in women with borderline personality disorder (BPD). Pain report and EEG power spectrum density during a laboratory pain procedure, a 4-min 10 degrees C cold pressor test (CPT), were compared among four groups; female inpatients with BPD who do (BPD-P group, n = 22) and do not (BPD-NP group, n = 19) report pain during self-injury, female inpatients with major depression (n = 15), and normal women (n = 20). The BPD-NP group reported less pain intensity during the CPT compared to the other groups. Total absolute theta power was significantly higher in the BPD-NP group compared to the Depressed (P = 0.0074) and Normal (P = 0.0001) groups, with a trend toward being significantly higher compared to the BPD-P group (P = 0.0936). Dissociative Experience Scale scores were significantly higher in the BPD-NP group compared to the Depressed and Normal groups (maximum P = 0.0004), and significantly higher in the BPD-P group compared to the Normal group (P = 0.0016). Beck Depression Inventory and Sheehan Patient Rated Anxiety Scale scores were significantly lower in the Normal group compared to all patient groups. Theta activity was significantly correlated with pain rating (Pearson partial r = -0.43, P = 0.0001) and Dissociative Experiences Scale score (Pearson partial r = 0.32, P = 0.01).

Adolescent↗

PubMed1999

Ragwort poisoning.

Explore the source record for details and available documents.

Agricultural Workers' Diseases↗

PubMed1999

Design and synthesis of isoxazoline derivatives as factor Xa inhibitors. 1.

Thrombosis is a major cause of mortality in the industrialized world. Therefore, the prevention of blood coagulation has become a major target for new therapeutic agents. One attractive approach is the inhibition of factor Xa (FXa), the enzyme directly responsible for prothrombin activation. We report a series of novel biaryl-substituted isoxazoline derivatives in which the biaryl moiety was designed to interact with the S(4) aryl-binding domain of the FXa active site. Several of the compounds herein have low nanomolar affinity for FXa, have good in vitro selectivity for FXa, and show potent antithrombotic efficacy in vivo. The three most potent compounds (33, 35, and 37) have inhibition constants for human FXa of 3.9, 2.3, and 0.83 nM, respectively, and ID(50)'s ranging from 0.15 to 0.26 micromol/kg/h in the rabbit arterio-venous thrombosis model.

Acetates↗

PubMed1999

The tomato DWARF enzyme catalyses C-6 oxidation in brassinosteroid biosynthesis.

Brassinosteroids (BRs) are steroidal plant hormones essential for normal plant growth and development. Mutants in the biosynthesis or perception of BRs are usually dwarf. The tomato Dwarf gene (D), which was predicted to encode a cytochrome P450 enzyme (P450) with homology to other P450s involved in BR biosynthesis, was cloned previously. Here, we show that DWARF catalyses the C-6 oxidation of 6-deoxocastasterone (6-deoxoCS) to castasterone (CS), the immediate precursor of brassinolide. To do this, we first confirmed that the D cDNA complemented the mutant light- and dark-grown phenotypes of the extreme dwarf (dx) allele of tomato. To identify a substrate for the DWARF enzyme, exogenous application of BR intermediates to dx plants was carried out. C-6 oxoBR intermediates enhanced hypocotyl elongation whereas the C-6 deoxoBR, 6-deoxoCS, had little effect. Quantitative analysis of endogenous BR levels in tomato showed mainly the presence of 6-deoxoBRs. Furthermore, dx plants were found to lack CS and had a high level of 6-deoxoCS in comparison to D plants that had CS and a lower level of 6-deoxoCS. Confirmation that DWARF catalyzed the C-6 oxidation of 6-deoxoCS to CS was obtained by functional expression of DWARF in yeast. In these experiments, the intermediate 6alpha-hydroxycastasterone was identified, indicating that DWARF catalyzes two steps in BR biosynthesis. These data show that DWARF is involved in the C-6 oxidation in BR biosynthesis.

Journal Article↗

PubMed1999

Does arthritis influence perceived ability to fulfill a parenting role? Perceptions of mothers, fathers and grandparents.

The presence of a painful, disabling chronic disease may have implications for perceived ability to fulfill a parenting role. The purpose of this research was to examine the realities of parenting from the perspectives of mothers, fathers and grandparents with arthritis using a combination of methods: a cross sectional survey and in-depth focus group discussions. There was consensus that pain, fatigue and restricted physical functioning combined to interfere with the parenting role. Overall, approximately 35% of the sample had experienced difficulties attributed to arthritis. A gender difference emerged with women reporting more difficulties in relation to caring for babies and toddlers, whereas men reported more problems as children grew older. Key themes concerned: physical limitations; practical and caring issues; social factors; emotional response; hereditary risks and safety issues. Perceived inability to fulfill parenting roles resulted in feelings of frustration, guilt, anger and depression. A number of positive outcomes were mentioned including children's increased awareness of the needs of others. Limitations of the methodological approach adopted are discussed.

Activities of Daily Living↗

PubMed1999

Active suppression of interneuron programs within developing motor neurons revealed by analysis of homeodomain factor HB9.

Sonic hedgehog (Shh) specifies the identity of both motor neurons (MNs) and interneurons with morphogen-like activity. Here, we present evidence that the homeodomain factor HB9 is critical for distinguishing MN and interneuron identity in the mouse. Presumptive MN progenitors and postmitotic MNs express HB9, whereas interneurons never express this factor. This pattern resembles a composite of the avian homologs MNR2 and HB9. In mice lacking Hb9, the genetic profile of MNs is significantly altered, particularly by upregulation of Chx10, a gene normally restricted to a class of ventral interneurons. This aberrant gene expression is accompanied by topological disorganization of motor columns, loss of the phrenic and abducens nerves, and intercostal nerve pathfinding defects. Thus, MNs actively suppress interneuron genetic programs to establish their identity.

Animals↗

PubMed1999

Endemic nosocomial gram-negative bacteraemias resulting from contamination of intravenous heparin infusions.

Following several cases of Gram-negative bacteraemia secondary to intravenous heparin infusion contamination, we retrospectively reviewed nosocomial bacteraemias associated with heparin infusions at our institution. Thirty-one episodes of heparin-infusion related bacteraemia occurred in 30 patients over a 23-month period affecting 2% patients receiving heparin infusions for more than 48 h. Gram-negative bacteria were responsible for all bacteraemias. The care of infusions during clinical use was prospectively surveyed, revealing that approximately 20% of lines and cannulae were left for more than 72 h before replacement, and significant discordance occurred between line replacement and syringe and cannula exchange. We concluded that contamination of the infusions was probably extrinsic and secondary to manipulations of the system during use. Prolonged usage and discordant exchange of infusion components were likely important factors in initial contamination and subsequent bacterial proliferation. The problem resolved following the introduction of a policy for routine and simultaneous replacement of lines and syringes at 24-h intervals and upon cannula exchange.

Anticoagulants↗

PubMed1999

Consulting the 'experts': children's and parents' perceptions of psycho-educational interventions in the context of juvenile chronic arthritis.

There is little documented information regarding current provision of psycho-educational interventions in the context of juvenile chronic arthritis (JCA). The purpose of the present exploratory study was to gain insight and understanding of the needs and preferences of children with JCA and their parents, and to examine how these may be more adequately addressed by future psycho-educational interventions. Data were collected through focus group discussions with children, parents and health professionals, respectively. Results showed that the voices of children and their parents were as one in calling for greater availability, easier access and more comprehensive psycho-educational interventions in the context of JCA. Greater emphasis is needed upon the social and emotional aspects of chronic disease, and enhancing the self-management skills of children and their families. Moreover, content should be tailored to match broad categories of disease severity (e.g. mild or severe), developmental age and stage in the life course (e.g. child or adolescent). Group education, informal support groups, activity weekends and summer camps would be particularly welcomed by parents and children, and may serve to reduce their sense of isolation whilst providing much needed reassurance. Findings provide a useful set of signposts to guide future development of psycho-educational interventions in the field of psychosocial paediatric rheumatology.

Adult↗

PubMed1999

Contribution of the assisted reproductive technologies to fertility in males suffering spinal cord injury.

This study reviews 19 couples referred between 1990 and 1997 for fertility treatment for anejaculatory infertility in the male partner following spinal injury. Using sperm obtained by assisted ejaculation procedures, 14 of the 19 patients (74%) achieved at least 1 pregnancy. Pregnancy rates per treatment cycle were 12.0% for timed intrauterine insemination, 38.9% for gamete intra-Fallopian transfer and 19.2% for intracytoplasmic sperm injection followed by uterine embryo transfer. Choice of the appropriate assisted reproduction treatment to match the available semen quality results in a high level of success in such patients.

Adult↗

PubMed1999

Suicides in an Australian inpatient environment.

Associated stressful life events both within and outside the hospital environment may contribute to the high-risk environment. The cohort studied here was hospitalized for a significant psychiatric problem, a factor which puts them in the high-risk category. When the severe psychiatric diagnosis is combined with a significant stressful life event, the risk of suicide is increased significantly.

Adult↗

PubMed1998

Job terminations among persons with severe mental illness participating in supported employment.

For persons with psychiatric disabilities, maintaining a job is often more difficult than acquiring a job. A large proportion of jobs end unsatisfactorily. This study explored job terminations among 63 persons with severe mental illness who participated in competitive jobs through supported employment programs. More than half of the job terminations were unsatisfactory, defined as the client quitting without having other job plans or being fired. Baseline ratings of demographic and clinical characteristics, preemployment skills training, and early ratings of job satisfaction and work environment did not predict unsatisfactory terminations. Clients with better work histories were less likely to experience unsatisfactory terminations. In addition, unsatisfactory terminations were associated retrospectively with multiple problems on the job that were related to interpersonal functioning, mental illness, dissatisfaction with jobs, quality of work, medical illnesses, dependability, and substance abuse. These results suggest that supported employment programs need to address job maintenance with interventions that identify and address different types of difficulties as they arise on the job.

Adult↗

PubMed1998

Influence of various combinations of specific antibody dose and affinity on tissue imipramine redistribution.

1. This study was designed to evaluate the distribution kinetics of imipramine (Imip) in the brain and the main peripheral organs (heart, kidney, liver and lung) of rats, and to establish the relationship between the redistribution of Imip from these tissues and the immunoreactive capacity (dose and affinity) of anti-TCA IgG. 2. [3H]-Imip (1 nmol kg(-1) body weight) was injected intravenously 6 min before the i.v. injection of antibodies. At this time, the concentrations of Imip and its main metabolites in plasma were determined. The radioactivity measured corresponded to 91.7% Imip, indicating that the pharmacokinetics reflected essentially Imip. Plasma and tissue Imip contents were measured over the interval 1 to 90 min in control and in treated rats. The antibodies used were a murine monoclonal IgG1 (Ka=3.8 10(7) M(-1)) at an IgG1/Imip molar ratio of 1000 (IgG1 1000), and a sheep polyclonal IgG (TAb, Ka=1.3 10(10) M(-1)) at IgG/ Imip molar ratios of 1, 10 and 100 (TAb1, TAb10 and TAb100). 3. The anti-TCA IgG increased the plasma [3H]-Imip concentrations: the AUC1-->60 min for [3H]-Imip were 4 (IgG1 1000), 9 (TAb1), 33.9 (TAb10) and 41.4 (TAb100) times higher in the treated groups than in the controls. The opposite effect occurred in the brain, heart and lungs, with large, rapid decreases in Imip. The increase in plasma Imip and the decrease in tissue Imip depended on the immunoreactive capacity (NKa) of the antibody, where N=molar concentration of IgG binding sites and Ka=IgG affinity constant. Maximal plasma and tissue redistribution occurred when NKa=33.8 x 10(4). 4. Imip redistribution can be controlled using various doses or affinities of specific antibodies, and the resulting rapid, extensive Imip redistribution from the main target organs could be very promising for TCA detoxification.

Animals↗

PubMed1998

Redistribution of imipramine from regions of the brain under the influence of circulating specific antibodies.

The kinetics of brain-to-blood redistribution of imipramine (IMI) was assessed in nine brain regions of control rats and rats given anti-tricyclic antidepressant (anti-TCA) antibody. Two antibodies were given intravenously 6 min after intravenous [3H]IMI (1 nmol/kg). One was a murine monoclonal IgG1 (Ka = 3.8 x 10(7) M(-1)) at an IgG/IMI molar ratio of 1,000 (IgG1,000), and the other was a sheep polyclonal IgG (TAb; Ka = 1.3 x 10(10) M(-1)) at IgG/IMI molar ratios of 1, 10, and 100 (TAb1, TAb10, and TAb100). In the control rats, IMI was rapidly taken up by the brain (Cmax at 5 min) with no significant differences among the brain regions (4.1 +/- 0.4 to 5.4 +/- 0.6 pmol/ g), and brain IMI then declined monoexponentially with a half-life of 44.2 min (cerebellum) to 77.3 min (hippocampus). The greatest IMI content was in the frontal cortex and the lowest in the cerebellum. The antibodies (except TAb1) stimulated the extent and rate of IMI redistribution from all the brain regions depending on the immunoreactive capacity (NKa) of the antibody. The antibody with the highest NKa (TAb100) had the greatest effect. The fraction of IMI removed from the brain was 58-74%, and the redistribution half-life was 7.9-15.6 min; the mean residence time was reduced by 66-75% (11.8-23.9 min). These results demonstrate that circulating anti-TCA IgG rapidly and reliably removes IMI from the brain, indicating that immunotoxicotherapy could be an efficient procedure for accelerating the removal of TCA from the brain.

Animals↗

PubMed1998

The tomato Cf-5 disease resistance gene and six homologs show pronounced allelic variation in leucine-rich repeat copy number.

The tomato Cf-2 and Cf-5 genes confer resistance to Cladosporium fulvum and map to a complex locus on chromosome 6. The Cf-5 gene has been isolated and is predicted to encode a largely extracytoplasmic protein containing 32 leucine-rich repeats (LRRs), resembling the previously isolated Cf-2 gene, which has 38 LRRs. Three haplotypes of this locus from Lycopersicon esculentum, L. pimpinellifolium, and L. esculentum var cerasiforme were compared, and five additional homologs of Cf-5 were sequenced. All share extensive sequence identity, particularly within the C-terminal portions of the predicted proteins. In striking contrast to the Cf-9 gene family, six of seven homologs in the Cf-2/Cf-5 gene family vary in LRR copy number, ranging from 25 to 38 LRRs. Cf-5 and one adjacent homolog differ by only two LRRs. Recombination events that vary the LRR copy number in this region could provide a mechanism for the generation of new specificities for recognition of different ligands. A recombination breakpoint between the Cf-2 and Cf-5 loci was fully characterized and shown to be intragenic.

Alleles↗

PubMed1998

The tomato Cf-9 disease resistance gene functions in tobacco and potato to confer responsiveness to the fungal avirulence gene product avr 9

The Cf-9 gene encodes an extracytoplasmic leucine-rich repeat protein that confers resistance in tomato to races of the fungus Cladosporium fulvum that express the corresponding avirulence gene Avr 9. We investigated whether the genomic Cf-9 gene functions in potato and tobacco. Transgenic tobacco and potato plants carrying Cf-9 exhibit a rapid hypersensitive cell death response (HR) to Avr 9 peptide injection. Cf 9 tobacco plants were reciprocally crossed to Avr 9-producing tobacco. A developmentally regulated seedling lethal phenotype occurred in F1 progeny when Cf9 was used as the male parent and Avr 9 as the female parent. However, when Cf9 was inherited in the maternal tissue and a heterozygous Avr 9 plant was used as the pollen donor, a much earlier reaction was caused, leading to no germination of any F1 seed. Detailed analysis of the Avr 9-induced responses in Cf 9 tobacco leaves revealed that (1) most mesophyll cells died within 3 hr (compared with 12 to 16 hr in tomato); (2) the macroscopic HR was visible at an Avr 9 titer five times lower than that which caused visible symptoms in tomato; (3) the HR invariably extended into noninjected panels of the tobacco leaf; (4) no HR occurred in leaves of young tobacco plants; (5) in older plants, the HR was dramatically enhanced by sequential Avr 9 challenges; and (6) coexpression of a salicylate hydroxylase transgene (nahG) from Pseudomonas putida reduced the severity of the macroscopic leaf HR and also restored germination to Cf 9 x 35S:Avr 9 F1 seedlings. Simultaneous introduction of Cf-9 homologs (Hcr 9-9 genes A and B or D) along with the native Cf-9 gene did not alter the responses that were specifically induced by Avr 9. Various ways to use the Cf-9-Avr 9 gene combination to engineer broad-spectrum disease resistance in several solanaceous species are discussed.

Journal Article↗

PubMed1998

Oral/pharyngeal, laryngeal, and lung cancer discharge trends in Department of Veterans Affairs hospitals.

OBJECTIVE: This paper describes trends in oral and pharyngeal (O/P) cancer diagnoses in Department of Veterans Affairs (VA) hospitals from 1983 to 1993 and compares these trends to those of laryngeal and lung cancers. METHODS: The VA patient treatment file was used to identify unique hospital discharges from 1983 to 1993 having ICD-9-CM codes for O/P, laryngeal, and lung cancers. Descriptive statistics were tabulated to determine prevalence and distribution. Trends of change over time were analyzed using regression analyses of the percent rate on year. RESULTS: Between 1983 and 1993 the annual number of O/P cases among users of VA hospitals decreased from 4,983 to 3,298. Despite overall declines in O/P cancer discharges in VA, cancer of the pharynx, tongue, and salivary gland continues to increase. O/P cancer in younger persons also continues to increase in VA. Overall, laryngeal cancers significantly increased, while no significant change was associated with lung cancer. CONCLUSIONS: VA needs to evaluate the changes in the patterns of O/P cancer to ascertain whether this represents a shift in care from inpatient to outpatient care. VA should seek further information regarding these trends to better plan, implement, and evaluate programs to provide early diagnosis and treatment targeted to veterans.

Age Factors↗

PubMed1998

Molecular, genetic and physiological analysis of Cladosporium resistance gene function in tomato.

Characterization of the DNA sequence of 4 tomato leaf mould disease resistance genes (Cf-2, Cf-4, Cf-5 and Cf-9) leads to the prediction that they encode C-terminally membrane anchored glycopeptides with many extracytoplasmic leucine rich repeats (LRRs). The N terminal LRRs are variable between the Cf-genes, suggesting a role in specificity, and the C terminal LRRs are more conserved, suggesting a role in signal transduction. Genetic analysis has revealed several Rcr genes that are required for Cf-gene function; their isolation will help us understand how Cf-genes work. Cf-9 confers responsiveness to pathogen-encoded Avr9 peptide on introduction to tobacco. Tobacco suspension cultures carrying the Cf-9 gene produce reactive oxygen species in response to Avr9 peptide, whereas untransformed cultures do not. The significance of these observations is discussed.

Cladosporium↗

PubMed1997

Novel disease resistance specificities result from sequence exchange between tandemly repeated genes at the Cf-4/9 locus of tomato.

Tomato Cf genes confer resistance to C. fulvum, reside in complex loci carrying multiple genes, and encode predicted membrane-bound proteins with extracytoplasmic leucine-rich repeats. At least two Cf-9 homologs confer novel C. fulvum resistance specificities. Comparison of 11 genes revealed 7 hypervariable amino acid positions in a motif of the leucine-rich repeats predicted to form a beta-strand/beta-turn in which the hypervariable residues are solvent exposed and potentially contribute to recognition specificity. Higher nonsynonymous than synonymous substitution rates in this region imply selection for sequence diversification. We propose that the level of polymorphism between intergenic regions determines the frequency of sequence exchange between the tandemly repeated genes. This permits sufficient exchange to generate sequence diversity but prevents sequence homogenization.

Amino Acid Sequence↗