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S Pollard

Publications and source records attributed to S Pollard.

At least 19 recordsLinked to original sources
PubMed2026

Impact of precision oncology research in pediatric poor prognosis cancer: patient, parent and healthcare provider perspectives.

BACKGROUND: Comprehensive genomic analyses are increasingly accessible to children, adolescents and young adults (AYAs) with poor prognosis cancers. Challenges and successes of pediatric precision oncology studies from the perspectives of AYA patients, parents and healthcare providers (HCPs) are poorly described. METHODS: Between March 2021 and May 2023, we interviewed AYA patients (12-21 years), parents and HCPs who participated in pediatric precision oncology studies for poor prognosis cancers in British Columbia. Interviews followed an investigator-developed semi-structured topic guide. Data were coded inductively and deductively by one qualitative researcher and one trainee, supported by two additional team members. Analytic themes were established using qualitative thematic analysis. RESULTS: We interviewed 9 AYAs, 10 parents, and 17 HCPs. We identified five analytic themes: importance of clear communication of study information between patients, families and multidisciplinary HCPs; a need to support disclosure, understanding and clinical integration of research results; barriers to accessing innovative therapy and mitigation strategies; approaches to managing parent, patient and HCP hopes and expectations; personal challenges and stressors related to participation. CONCLUSIONS: We highlight unmet needs and offer practical considerations for integrating precision oncology into clinical practice. Considerations include educating and supporting oncologists through genomics results disclosure, increasing engagement with multidisciplinary HCPs, streamlining access to study information and results, coordinating efforts to clinically validate results and access therapies, and establishing real-world outcome data to inform clinical decision-making. Implementation of these strategies will optimize care for patients and families who are navigating poor prognosis cancers.

Humans↗
PubMed1992

Quantitative immunoprecipitation studies with anti-gamma-aminobutyric acidA receptor gamma 2 1-15 Cys antibodies.

Antibodies raised against the synthetic peptide NH2-QKSDDDYEDYASNKTC-COOH (gamma 2 1-15 Cys), which corresponds to the N-terminal amino acid sequence with a C-terminal cysteine of the human gamma 2 subunit of the gamma-aminobutyric acidA (GABAA) receptor, were used to study the quantitative immunoprecipitation of agonist benzodiazepine binding sites from bovine brain. Anti-gamma 2 1-15 Cys antibodies were found to immunoprecipitate specifically in parallel [3H]flunitrazepam- and [3H]muscimol-reversible binding sites in a dose-dependent manner. The maximum percentages of [3H]flunitrazepam binding sites immunoprecipitated from detergent extracts of bovine cerebral cortex, cerebellum, and hippocampus were 68, 77, and 83%, respectively. Immunoprecipitation studies with anti-alpha 1 324-341 antibodies carried out in parallel with anti-gamma 2 1-15 Cys antibodies provided evidence for the promiscuity of the gamma 2 subunit within native GABAA receptors. These results substantiate the association of the gamma 2 polypeptide with native GABAA receptors.

Amino Acid Sequence↗
PubMed1991

Immunoaffinity purification of GABAA receptor alpha-subunit iso-oligomers. Demonstration of receptor populations containing alpha 1 alpha 2, alpha 1 alpha 3, and alpha 2 alpha 3 subunit pairs.

Novel methods for the isolation of gamma-aminobutyric acidA (GABAA) receptor alpha subunit iso-oligomers have been developed. Thus, populations of GABAA receptors containing the GABAA receptor alpha 1 subunit, the alpha 2 subunit, and the alpha 3 subunit have been purified from sodium deoxycholate extracts of bovine cerebral cortex with the retention of specific [3H]flunitrazepam-binding activity by anti-alpha 1 324-341, anti-Cys alpha 2 414-424, or anti-Cys alpha 3 454-467 antibody affinity chromatography, respectively. The relative abundance of the different specificity alpha subunits in these preparations was compared with benzodiazepine affinity chromatography-purified GABAA receptors by immunoblotting. In each case, it was found that although the immunoreactivity with the specific alpha subunit antibody that was used for purification was enriched in immunoaffinity-purified receptors, reactivity with the other alpha subunit specificity antibodies, together with anti-gamma 2 1-14 Cys immunoreactivity was found. Immunoprecipitation of GABAA receptors purified by anti-alpha 1 324-341 antibody affinity chromatography by all three anti-alpha subunit antibodies employed, together with the use of anti-alpha 1 324-341 and anti-Cys alpha 2 414-424 antibody affinity columns in series, further substantiated the partial co-purification of the different polypeptides. These results demonstrate the copurification of the gamma 2 subunit with each population of alpha 1, alpha 2, alpha 3 subunit-enriched GABAA receptors. They also show the existence of minor populations of GABAA receptors that contain alpha 1 alpha 2, alpha 1 alpha 3, and alpha 2 alpha 3 subunit pairs within single oligomers.

Animals↗
PubMed1991

Promiscuity of GABAA-receptor beta 3 subunits as demonstrated by their presence in alpha 1, alpha 2 and alpha 3 subunit-containing receptor subpopulations.

Polyclonal antibodies were raised in rabbits against the GABAA-receptor beta 3 subunit peptide sequence, KQSMPREGHGRHMDR-NH2 coupled to keyhole limpet haemocyanin. These anti-beta 3 379-393 antibodies immunoprecipitated in a dose-dependent manner specific benzodiazepine agonist binding sites from Na+ deoxycholate extracts of bovine cerebral cortex. In immunoblots, anti-beta 3 379-393 antibodies recognised two species with Mr 59,900 and Mr 57,200 in all preparations tested, which included crude detergent-solubilised, benzodiazepine affinity chromatography-purified receptor, anti-alpha 1 324-341 antibody, anti-Cys alpha 2 414-424 antibody and anti-Cys alpha 3 454-467 antibody immunoaffinity-purified GABAA-receptor subpopulations. These results provide evidence for the ubiquity and promiscuity of the GABAA-receptor beta 3 subunit.

Amino Acid Sequence↗
PubMed1991

Lack of chondrogenic expression in mouse limb bud micromass cultures exposed to exogenous beta galactosidase or N-acetyl-beta-glucosaminidase.

The effect of two exoglycosidases, beta-galactosidase and N-acetyl-beta-glucosaminidase (GlcNAc-ase) on chondrogenic expression of stage 19 mouse limb bud micromass cultures was investigated. Chondrogenic expression was monitored by Alcian blue staining and immunofluorescent localization of cartilage-specific proteoglycan and type II collagen. Chondrogenesis was inhibited by exposure to 0.1 U/ml beta-galactosidase or 0.025 U/ml GlcNAc-ase for 24 h or longer in culture. The effect of both enzymes was concentration and time dependent. Exoglycosidic hydrolysis of galactose or N-acetylglucosamine was substantiated by treatment with HRP-conjugated peanut agglutinin and succinylated wheat germ agglutinin, respectively. Cells treated with beta-galactosidase appeared to be flattened with a stellate morphology, whereas GlcNAc-ase-treated cells were bipolar forming ridge-like mounds that had a directional orientation. The antichondrogenic effect was not alleviated when the cells were induced to assume a spherical shape upon treatment with cytochalasin D. DNA measurements indicated that the lack of chondrogenic expression was not related to cell attachment or cell proliferation. These data support the hypothesis that the expression of specific terminal sugars on cell surface glycoconjugates of limb bud cells represents an important component of the chondrogenic process.

Acetylglucosaminidase↗
PubMed1990

The gamma 2 subunit is an integral component of the gamma-aminobutyric acidA receptor but the alpha 1 polypeptide is the principal site of the agonist benzodiazepine photoaffinity labeling reaction.

Polyclonal antibodies were raised to a synthetic peptide whose amino acid sequence was derived from the novel gamma-aminobutyric acidA (GABAA) receptor subunit, gamma 2. These anti-gamma 2 1-15 Cys antibodies reacted specifically with the GABAA receptor purified from adult bovine cerebral cortex in an enzyme-linked immunosorbent assay. Anti-gamma 2 1-15 Cys antibodies specifically immunoprecipitated [3H]flunitrazepam photoaffinity-labeled native receptor in parallel with anti-alpha 1 324-341 antibodies. Immunoprecipitation of sodium dodecyl sulphate (SDS) denatured photoaffinity-labeled receptor by anti-gamma 2 1-15 Cys antibodies, however, resulted in a significant decrease in the maximum percentage of radioactivity immunoprecipitated compared to that by anti-alpha 1 324-341 antibodies. In immunoblots, anti-gamma 2 1-15 Cys antibodies reacted with a broad band in the molecular weight range Mr 43,000-49,000 which was distinct from that recognized by anti-alpha 1 324-341 antibodies. The anti-alpha 1 324-341 immunoreactive band was the main subunit irreversibly photoaffinity labeled by [3H]flunitrazepam, i.e. Mr 53,000. These results demonstrate for the first time that the gamma 2 subunit is an integral component of the GABAA receptor but it is the alpha 1 subunit that is the principal site of the agonist benzodiazepine photoaffinity labeling reaction. It supports a role of both the alpha 1 and gamma 2 polypeptides in the formation of the central benzodiazepine binding site within a GABAA receptor oligomer.

Affinity Labels↗
PubMed1987

Slimming diets.

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Diet Fads↗
PubMed1987

Traumatic rupture of the diaphragm.

Diaphragmatic disruption is an uncommon consequence of blunt trauma and is easily overlooked unless a high index of suspicion is maintained. The diagnosis is important because of the high incidence of associated organ damage and the complications of a missed injury. This article outlines the clinical features and management of the condition.

Abdominal Injuries↗
PubMed1985

Chronic progressive multiple sclerosis. Relationship between cerebral ventricular size and neuropsychological impairment.

Forty-seven patients with chronic progressive multiple sclerosis were examined to assess the possible relationship between cerebral atrophy (by computed tomography [CT] ) and performance on neuropsychological tests of memory and verbal intelligence. Nineteen patients were found to have mildly dilated ventricles and another nine patients had moderate to severe ventricular enlargement. Performance on memory and intelligence testing was related to the degree of ventriculomegaly. Three linear CT measurements were also recorded. Using this method, the width of the third ventricle proved to be the best indicator of intellectual and memory dysfunction. Measures of cognition and ventricular size did not correlate with length of illness or overall disability as rated by the Kurtzke Disability Status Score.

Adult↗
PubMed1985

Effects of age on the mother-child interactions of ADD-H and normal boys.

The interactions of 60 ADD-H boys with their mothers were compared to those of 60 normal boys during both free-play and task situations. Both groups were equally subdivided into five age levels (years 5, 6, 7, 8, and 9). In free play, ADD-H boys played more independently of and were more negative toward their mothers, while their mothers gave more commands and initiated fewer interactions than normal mother-child dyads. There were no effects of age in this setting. During the task setting, ADD-H boys were less compliant, sustained their compliance for shorter time periods, and were more negative and off task than the normal boys. Mothers of ADD-H boys gave more commands, were more negative, initiated fewer interactions, and responded with greater control over both compliance and off-task behavior than did normal mothers. Several age effects were noted suggesting that older boys in both groups were more compliant while their mothers gave fewer commands and controlled their compliance less than the mother-child dyads of younger boys. While the interactions of ADD-H boys appear to improve with age, the boys continue to display a developmental lag in social behavior that is more evident with increasing situational demands.

Age Factors↗