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Biomedical subjects

K Harrison

Publications and source records attributed to K Harrison.

At least 55 records · Page 3Linked to original sources

Home care triage nurse.

As a TN who began in a position with little insight into the expectations and who has been able to develop the system into one that ideally meets the needs of our home care institution, I always feel challenged. Initially, my concern was that I would lose touch with what was new and would lose my clinical skills. To the contrary, I feel that I have honed my skills. By understanding the steps to procedures and their rationale, disease processes, symptoms, treatment regimes, and through continuing education, I have become confident in teaching patients and caregivers over the phone. Although the staff includes those in each of our branches, I am able to have contact with them all now more than ever. Because we known as home care workers that it is difficult to develop relationships and trust among staff members because of the independent nature of home care nursing, forging a relationship based on trust between the staff members and the TN is crucial for delivering consistent patient care 24 hours a day, 7 days a week. It is note-worthy that to develop the TN system effectively, I was granted autonomy and lent support by the agency administration and management. This autonomy continues to be instrumental for success.

Home Care Services↗

Characterization of the tomato Cf-4 gene for resistance to Cladosporium fulvum identifies sequences that determine recognitional specificity in Cf-4 and Cf-9.

In many interactions between plants and their pathogens, resistance to infection is specified by plant resistance (R) genes and corresponding pathogen avirulence (Avr) genes. In tomato, the Cf-4 and Cf-9 resistance genes map to the same location but confer resistance to Cladosporium fulvum through recognition of different avirulence determinants (AVR4 and AVR9) by a molecular mechanism that has yet to be determined. Here, we describe the cloning and characterization of Cf-4, which also encodes a membrane-anchored extracellular glycoprotein. Cf-4 contains 25 leucine-rich repeats, which is two fewer than Cf-9. The proteins have > 91% identical amino acids. DNA sequence comparison suggests that Cf-4 and Cf-9 are derived from a common progenitor sequence. Amino acid differences distinguishing Cf-4 and Cf-9 are confined to their N termini, delimiting a region that determines the recognitional specificity of ligand binding. The majority of these differences are in residues interstitial to those of the leucine-rich repeat consensus motif. Many of these residues are predicted to form a solvent-exposed surface that can interact with the cognate ligand. Both Cf-4 and Cf-9 are located within a 36-kb region comprising five tandemly duplicated homologous genes. These results provide further insight into the molecular basis of pathogen perception by plants and the organization of complex R gene loci.

Amino Acid Sequence↗

High-dose therapy with iodine-131-labeled monoclonal antibody CC49 in patients with gastrointestinal cancers: a phase I trial.

PURPOSE: A phase I trial that evaluated for extrahematopoietic toxicity was conducted with iodine-131 (131I) labeled monoclonal antibody (MAb) CC49. Correlative studies included pharmacokinetic and biodistribution analyses, estimates of absorbed radiation dose, and measurement of human antimonoclonal antibodies (HAMA). PATIENTS AND METHODS: After collection and cryopreservation of hematopoietic stem cells, 15 patients with gastrointestinal cancers were administered a tracer dose of 131I-MAb CC49. Within 5 to 6 days, 14 patients (two to three per activity level) underwent a single treatment with 131I-MAb CC49 (50, 100, 150, 200, 250, and 300 mCi/m2). Biodistribution was determined using planar and single photon emission computer tomographic (SPECT) imaging. Pharmacokinetic studies were performed by measuring radioactivity in serial blood samples. In some patients, biopsies of metastases and related normal tissues were obtained for radioactivity measurements. Radiation dosimetry estimates were calculated using available biodistribution, pharmacokinetic, and tissue biopsy data. Toxicity was evaluated using the National Cancer Institute (NCI) Common Toxicity Criteria. RESULTS: No dose-limiting extrahematopoietic toxicity was identified. Twelve patients experienced grade IV myelosuppression and met criteria for infusion of hematopoietic stem cells. Radioimmunolocalization was excellent. The T1/2 for 131I-MAb CC49 after diagnostic and therapeutic administration was 39.7 +/- 10.4 and 46.1 +/- 10.6 hours, respectively. The percent injected dose per killigram of tumor ranged from 0.2 to 2.1. Absorbed radiation dose in metastatic tumor sites ranged from 630 to 3300 cGy. CONCLUSION: Although extrahematopoietic dose-limiting toxicity was neither observed or predicted, suboptimal absorbed dose estimates suggested that further escalation of 131I-MAb CC49 would not be useful. Future studies should focus on the use of radionuclides with high energy beta emissions, such as yttrium 90, and on strategies to optimize access of antibody to target antigens.

Adenocarcinoma↗

Influence of column type and chromatographic conditions on the ion-exchange chromatography of immunoglobulins.

Immunoglobulins are often purified by affinity chromatography. However, this technique is costly, can result in poor resolution for subclasses (or is only group specific), and leads to possible leaching of contaminants into the purified products. Ion-exchange chromatography has shown great potential and has found an increased usage in the purification of immunoglobulins. The aim of this study is to further understand the separation mechanism with emphasis on the influence of column type and chromatographic conditions on the peak shape, selectivity and changes in the elution patterns. Included are strong cation-exchange, strong anion-exchange and weak anion-exchange columns. Five immunoglobulin G antibodies were used as test probes. Some sera and ascites were also used in the study. Among the chromatographic conditions examined were mobile phase pH, buffer type, buffer concentration, gradient rate, and column temperature. Significant differences in the chromatographic behavior (elution pattern, peak shape and selectivity) of the test samples are discussed in regard to the column type and the chromatographic conditions.

Animals↗

Pain and self-injury in borderline patients: sensory decision theory, coping strategies, and locus of control.

Fifteen women with borderline personality disorder who do not experience pain during self-injury were found to discriminate more poorly between imaginary painful and mildly painful situations, to reinterpret painful sensations (a pain-coping strategy related to dissociation), and to have higher scores on the Dissociative Experiences Scale than 24 similar female patients who experience pain during self-injury and 22 age-matched normal women. "Analgesia' during self-injury in borderline patients may be related to a cognitive impairment in the ability to distinguish between painful and mildly painful situations, as well as to dissociative mechanisms.

Adaptation, Psychological↗

The tomato Cf-2 disease resistance locus comprises two functional genes encoding leucine-rich repeat proteins.

In plants, resistance to pathogens is frequently determined by dominant resistance genes, whose products are proposed to recognize pathogen-encoded avirulence gene (Avr) products. The tomato resistance locus Cf-2 was isolated by positional cloning and found to contain two almost identical genes, each conferring resistance to isolates of tomato leaf mould (C. fulvum) expressing the corresponding Avr2 gene. The two Cf-2 genes encode protein products that differ from each other by only three amino acids and contain 38 leucine-rich repeat (LRR) motifs. Of the LRRs, 20 show extremely conserved alternating repeats. The C-terminus of Cf-2 carries regions of pronounced homology to the protein encoded by the unlinked Cf-9 gene. We suggest that this conserved region interacts with other proteins involved in activating plant defense mechanisms.

Amino Acid Sequence↗

Analysis of the Bruton's tyrosine kinase gene promoter reveals critical PU.1 and SP1 sites.

The gene defective in X-linked agammaglobulinemia (XLA) encodes a novel protein kinase termed Bruton's tyrosine kinase (Btk). Whereas the XLA phenotype is confined to abnormalities of B-cell development and function, Btk is expressed not only in B-lymphocyte lineage but also in myeloid lineage cells. The first 450 basepairs of the Btk promoter fused to a luciferase gene displayed a similar cell-type specificity. Critical binding sites for the transcription factors PU.1 and Sp1 were identified in the proximal portion of the Btk promoter upstream of a cluster of transcriptional start sites. Mutation of either the PU.1 or Sp1 site markedly reduced the activity of a Btk promoter-luciferase reporter construct in transfection experiments. In addition, PU.1 directly transactivated the Btk promoter, and deletion of the PU.1 binding site abolished this effect. This study implicates PU.1 and Sp1 as major regulators of Btk expression and provides a foundation for further study of the regulation of this gene in XLA patients that lack Btk mRNA.

Agammaglobulinaemia Tyrosine Kinase↗

The tomato Dwarf gene isolated by heterologous transposon tagging encodes the first member of a new cytochrome P450 family.

To transposon tag the tomato Dwarf (D) gene, a tomato line that carries a T-DNA containing a maize Activator (Ac) transposable element closely linked to D was pollinated with a stock homozygous for the d mutation. Hybrid seedlings were screened for dwarf progeny, and three independent dwarf lines were obtained. Two of these lines showed inheritance of a recessive phenotype similar to that conferred by the extreme dwarf (dx) allele. Variegation for the dwarf phenotype in one of these lines suggested that D had been tagged by Ac. Genomic DNA adjacent to Ac in these two lines was isolated by use of the inverse polymerase chain reaction, and the two insertions mapped approximately 2 kb apart. Partial complementation of d was observed when the corresponding wild-type sequence was used in transformation experiments. A cDNA clone of D was sequenced, and the predicted amino acid sequence has homology to cytochrome P450 enzymes.

Alleles↗

Non-prescribed drug use during methadone treatment by clinic- and community-based patients.

We investigated the efficacy of methadone maintenance treatment in clinic-based (n = 10) and community-based (n = 10) patients by studying the relationships between dose, plasma concentrations of methadone and non-prescribed drug-use using logistic regression. We found that clinic-based patients had significantly reduced odds of having a urine sample test positive for illicit drugs when compared to community-based patients (OR = 0.20; 95% confidence interval 0.10-0.38: p < 0.001). There was no relationship between either methadone dose or plasma methadone concentration and testing positive for non-prescribed drugs (including cocaine, cannabis, amphetamine, ecstasy, benzodiazepines). We looked specifically at the misuse of opiate drugs. Location was again important and clinic-based patients had significantly reduced odds of having a urine sample test positive for opiate drugs (OR = 0.36, 95% confidence interval 0.18-0.71: p approximately 0.004). Opiate drug use in our patients was also significantly related to plasma methadone concentration, increasing noticeably when the drug concentration < 0.48 nmol/L (p approximately 0.04). We found no relationship between methadone dose and odds of having a positive urine drug test in either clinic- or community-based patients.

Adult↗

Novel GUS expression patterns following transposition of an enhancer trap Ds element in Arabidopsis.

Enhancer trap derivatives of the maize Dissociation (Ds) transposon were introduced into Arabidopsis thaliana. The enhancer trap Ds was so designed that upon transposition to sites containing regulatory sequences in adjacent genomic DNA, transcription of a Ds-borne beta-glucuronidase (GUS) gene would be activated. Sixty percent of all transposition events were associated with GUS expression patterns including one linked to a mutant phenotype. Patterns of GUS expression were found in various organs and were stably inheritable in the F4 and F5 progenies. These results demonstrate the potential value of the technique as a means for detection of developmentally regulated genes and analysis of their function. The enhancer trap construct used in our experiments, as well as the seeds of primary transformants are publicly available.

Arabidopsis↗

Analysis of splice donor and acceptor site function in a transposable gene trap derived from the maize element Activator.

Gene trap vectors have been used in insertional mutagenesis in animal systems to clone genes with interesting patterns of expression. These vectors are designed to allow the expression of a reporter gene when the vector inserts into a transcribed region. In this paper we examine alternative splicing events that result in the expression of a GUS reporter gene carried on a Ds element which has been designed as a gene trap vector for plants. We have developed a rapid and reliable method based on PCR to study such events. Many splice donor sites were observed in the 3' Ac border. The relative frequency of utilisation of certain splice donor and acceptor sites differed between tobacco and Arabidopsis. A higher stringency of splicing was observed in Arabidopsis.

Arabidopsis↗

Medical eligibility, comprehension of the consent process, and retention of injection drug users recruited for an HIV vaccine trial.

Injection drug users (IDUs) at high risk for human immunodeficiency virus (HIV) infection are being identified as a population for HIV vaccine trials. We studied willingness of drug users to enroll and their comprehension of consent procedures in the context of a Phase II trial at one site. Of 175 people screened for enrollment and whose data sets were complete, 119 (68%) were IDUs. Of the 71 who were eligible, 39 (55%) were IDUs. Exclusion of IDUs was usually for medical reasons. Using a 17-item true/false test, comprehension of the informed consent procedure was high (median score, 16 of 17 for IDUs and non-IDUs); only three subjects (all of whom were IDUs) were excluded from enrollment due to lack of comprehension. Follow-up rates were similar for IDUs and non-IDUs. These data suggest that recruitment of IDUs into HIV vaccine trials is feasible, that IDUs can comprehend and complete the informed consent procedures, and that they return for follow-up visits.

AIDS Vaccines↗

Maternal uniparental disomy of chromosome 2 in a baby with trisomy 2 mosaicism in amniotic fluid culture.

We describe the first case of a baby with maternal uniparental disomy of chromosome 2. Growth failure, hypothyroidism, and hyaline membrane disease were present at birth, and the first year of life was complicated by bronchopulmonary dysplasia. At age 14 months, motor and intellectual development were normal, but growth remained below the 10th centile. The baby was investigated for uniparental disomy because trisomy 2 mosaicism had been detected in a second trimester amniocentesis. This is the first reported case in which amniotic fluid chromosome mosaicism has been associated with uniparental disomy. Implications for prenatal diagnosis are considered.

Amniocentesis↗

Clinical trial of fermented maize-based oral rehydration solution in the management of acute diarrhoea in children.

In an effort to identify appropriate fluids available in the home for oral rehydration therapy in Ghana, a study was designed to investigate the efficacy of fermented maize gruel, a popular Ghanaian traditional food, in the management of acute diarrhoea. Altogether 108 children aged between 4 and 27 months presenting with acute diarrhoea at the Princess Marie Louise Children's Hospital in Accra, with mild to moderately severe dehydration, were randomly assigned to treatment with either WHO/UNICEF oral rehydration solution (ORS) or fermented and unfermented maize solutions. About 35 children were admitted to each of the three treatment groups. Treatment with the rehydration fluid was maintained for 24 h. Efficacy of the various treatments, assessed in terms of fluid intake, stool output, stool frequency, weight gain and duration of diarrhoea, showed no significant variation among the three groups. The results indicate that the maize solutions were as effective as WHO/UNICEF ORS for oral rehydration therapy. However, the fermented maize was more readily accepted by the children than the unfermented solution. Because fermented maize gruel is widely consumed, inexpensive, readily available, and culturally acceptable to most communities in Ghana, it may be recommended as an appropriate home-available fluid for the management of acute diarrhoea in children at the community level.

Acute Disease↗

Germinal transpositions of the maize element Dissociation from T-DNA loci in tomato.

We have analyzed the pattern of germinal transpositions of artificial Dissociation (Ds) transposons in tomato. T-DNA constructs carrying Ds were transformed into tomato, and the elements were trans-activated by crossing to lines transformed with a stabilized Activator (sAc) that expressed the transposase gene. The sAc T-DNA carried a GUS gene to monitor its segregation. The Ds elements were inserted in a marker gene so that excision from the T-DNA could be monitored. The Ds elements also carried a genetic marker that was intended to be used for reinsertion selection of the elements after excision. Unfortunately, this gene was irreversibly inactivated on crossing to sAc. Germinal excision frequencies of Ds averaged 15-40%, but there was large variation between and within plants. Southern hybridization analysis of stable transposed Ds elements indicated that although unique transpositions predominate, early transposition events can lead to large clonal sectors in the germline of developing plants and to sibling offspring carrying the same transposition event. Multiple germinal transpositions from three different loci were examined for uniqueness, and 15 different transpositions were identified from each of three T-DNA loci that carried a single independent Ds. These were mapped relative to the donor T-DNA loci, and for each locus 70-80% of the transposed elements were closely linked to the donor site.

Base Sequence↗

Oral cavity and pharyngeal cancer among Department of Veterans Affairs hospital discharges.

OBJECTIVES: The purpose of this study is to determine the number of oral cavity and pharyngeal cancers among hospital discharges at Department of Veterans Affairs (VA) medical centers in one 12-month period. METHODS: A SAS file was created from the patient treatment file (PTF) with all discharges during fiscal 1990 having ICD-9-CM codes for oral cavity and pharyngeal cancer. Up to 10 discharge diagnoses from the most recent discharge summary were included in the data set. ICD-9-CM codes for alcohol dependence syndrome, drug dependence, and nondependent abuse of drugs also were included. ICD-9-CM codes for salivary and nasopharyngeal cancers were excluded. RESULTS: There were 3,733 unique individuals discharged with a diagnosis of oral cavity and pharyngeal cancer. The majority of cases (62%) were found in the oral cavity. The age distribution of oral cavity and pharyngeal cancer did not parallel the age distribution of veterans discharged during this year. Race and ethnicity of those discharged with the disease does not differ from that of all VA hospital discharges for 1990. CONCLUSIONS: VA data provide descriptive statistics of oral cavity and pharyngeal cancer among VA hospital discharges. VA data sets such as the PTF may offer the opportunity to examine hospital management issues, length of stay, and co-morbid diagnoses associated with oral cavity and pharyngeal cancer.

Adult↗

Developmentally regulated cell death on expression of the fungal avirulence gene Avr9 in tomato seedlings carrying the disease-resistance gene Cf-9.

Plant defense responses are induced when the products of disease-resistance genes and pathogen avirulence genes interact. We report here the effects of expressing the Cladosporium fulvum avirulence Avr9 gene product in a tomato line containing the Cf-9 disease-resistance gene. A synthetic Avr9 gene was constructed to produce constitutive high-level expression of AVR9 peptide in the plant apoplast. Avr9 expression in Cf-9-containing tomato lines is lethal, but cell death is developmentally regulated, in that necrosis is not visible until 10 days after planting seed. Plant lines lacking Cf-9 and expressing Avr9 remain healthy. The synthetic Avr9 gene exhibited the same specificity of action as the authentic C. fulvum Avr9 gene. Our results have significant implications for strategies using the gene combination Avr9/Cf-9 to engineer plants with enhanced disease resistance.

Amino Acid Sequence↗