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Biomedical subjects

H Richardson

Publications and source records attributed to H Richardson.

At least 37 records · Page 2Linked to original sources
PubMed2000

Determinants of low-risk and high-risk cervical human papillomavirus infections in Montreal University students.

BACKGROUND: Previous studies have been inconsistent about the degree of sexual transmissibility of cervical human papillomavirus (HPV) infection. The authors hypothesize that risk factors for HPV infection vary according to HPV type. GOAL: To estimate the prevalence of HPV infection in asymptomatic women and to identify risk factors for overall HPV infection and HPV infection by oncogenic and nononcogenic type. STUDY DESIGN: A cross-sectional survey was conducted at the McGill University clinic in Montreal. Cervical specimens were collected from 489 female students presenting at the clinic for a routine Papanicolaou test. Data on potential risk factors was obtained by questionnaire. Human papillomavirus DNA was detected by the polymerase chain reaction using consensus primers (MY09/11) followed by hybridization with generic and type-specific probes using Southern blot and dot blot techniques. RESULTS: The overall HPV prevalence was 21.8%. A low-risk HPV infection was found in 6.2% of the women, 11.8% had a high-risk HPV infection (types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58), 7.1% had an unknown HPV type, and 2.7% had a multiple type infection. Two profiles emerged for sexual activity and risk of HPV infection according to oncogenic risk after multivariate analysis. Lifetime frequency of sexual intercourse and lifetime number of oral sex partners was associated with high-oncogenic-risk HPV infections; however, HPV infection with low-oncogenic-risk types was invariant with respect to markers of sexual activity. CONCLUSION: These results suggest that there are differences in epidemiologic correlates of transmission between low-risk and high-oncogenic-risk HPV types based on oncogenicity. This finding has important implications for primary prevention of HPV infection and cervical cancer precursors.

Adolescent↗
PubMed2000

Tissue-specific regulation of cyclin E transcription during Drosophila melanogaster embryogenesis.

Cyclin E is an essential regulator of S phase entry. We have previously shown that transcriptional regulation of the gene that encodes Drosophila cyclin E, DmcycE, plays an important role in the control of the G(1) to S phase transition during development. We report here the first comprehensive analysis of the transcriptional regulation of a G(1 )phase cell cycle regulatory gene during embryogenesis. Analysis of deficiencies, a genomic transformant and reporter gene constructs revealed that DmcycE transcription is controlled by a large and complex cis-regulatory region containing tissue- and stage-specific components. Separate regulatory elements for transcription in epidermal cells during cell cycles 14-16, central nervous system cells and peripheral nervous system cells were found. An additional cis-regulatory element drives transcription in thoracic epidermal cells that undergo a 17th cell cycle when other epidermal cells have arrested in G(1 )phase prior to terminal differentiation. The complexity of DmcycE transcriptional regulation argues against a model in which DmcycE transcription is regulated simply and solely by G(1) to S phase transcription regulators such as RB, E2F and DP. Rather, our study demonstrates that tissue-specific transcriptional regulatory mechanisms are important components of the control of cyclin E transcription and thus of cell proliferation in metazoans.

Animals↗
PubMed2000

External quality assessment in the examination of blood films for malarial parasites within Ontario, Canada.

OBJECTIVE: To assess laboratory practice in the examination of blood films for malarial parasites. METHOD: Ontario medical laboratories, licensed by the Ministry of Health, are required to participate in external quality assessment by the Laboratory Proficiency Testing Program, which assesses performance of laboratory assays and also examines the total testing process. Educational strategies are used to improve performance. RESULTS: A 1995 survey indicated shortcomings in detection and identification of malarial parasites in blood films. Consequently, recommendations for the investigation of malarial parasites in blood were issued. In 1996 and 1997, 16 workshops were conducted. A 1997 follow-up external quality assessment survey indicated that problems persist as 27% of laboratories failed to correctly speciate Plasmodium falciparum. Good Practice Guidelines were issued in 1998. CONCLUSION: Further education and assessment are required. Laboratories lacking expertise must establish referral arrangements with more proficient laboratories.

Animals↗
PubMed2000

Prenatal education for mothers with disabilities.

Prenatal nurse educators are well prepared to meet the learning needs of many expectant mothers. But how prepared are they to meet the learning needs of mothers with disabilities? To answer this question, eight mothers with various chronic illnesses located in north-eastern Ontario, Canada were asked to describe their maternity experiences. Given the small convenience sample and exploratory nature of the study, a qualitative content analysis was done. The mothers' reports described interaction with a variety of health professionals. This analysis focuses on findings specific to nurses who provide prenatal education. In general, mothers reported they had received insufficient, inappropriate information, especially about their pregnancy and chronic illnesses. The mothers thought that nurses doubted the ability of women with disabilities to be decision-makers or responsible and 'proper' mothers. Suggestions by disabled mothers for quality care in prenatal education are described. A more emancipatory approach to preparing nurses for practice as prenatal educators is recommended. Such an approach can reduce the barriers associated with power differences between women with disabilities as 'learners' and their nurse 'teachers'.

Adult↗
PubMed2000

The 1999 Helene Fuld Health Trust Fellowship. Promoting leadership development in undergraduate nursing students.

In 1999, based on the recommendation of The Conservation Company. The Helene Fuld Health Trust selected New York University's Robert F. Wagner Graduate School of Public Service, in partnership with the Division of Nursing in the School of Education, to restructure its fellowship program for undergraduate nursing students. Bringing together an interdisciplinary team with experience in leadership development, nursing and health policy, and health care administration, NYU designed and delivered an innovative and state-of-the-art leadership development program for the 1999 Fuld Fellowship program. The new program started in June 1999 with 21 nursing students from all over the country. This article describes the goals and methods of the program; it also discusses early observations of the program's success that could be relevant to nursing education.

Education, Nursing, Baccalaureate↗
PubMed1999

DECAY, a novel Drosophila caspase related to mammalian caspase-3 and caspase-7.

Caspases are key effectors of programmed cell death in metazoans. In Drosophila, four caspases have been described so far. Here we describe the identification and characterization of the fifth Drosophila caspase, DECAY. DECAY shares a high degree of homology with the members of the mammalian caspase-3 subfamily, particularly caspase-3 and caspase-7. DECAY lacks a long prodomain and thus appears to be a class II effector caspase. Ectopic expression of DECAY in cultured cells induces apoptosis. Recombinant DECAY exhibited substrate specificity similar to the mammalian caspase-3 subfamily. Low levels of decay mRNA are ubiquitously expressed in Drosophila embryos during early stages of development but its expression becomes somewhat spatially restricted in some tissues. During oogenesis decay mRNA was detected in egg chambers of all stages consistent with a role for DECAY in apoptosis of nurse cells. Relatively high levels of decay mRNA are expressed in larval salivary glands and midgut, two tissues which undergo histolysis during larval/pupal metamorphosis, suggesting that DECAY may play a role in developmentally programmed cell death in Drosophila.

Amino Acid Sequence↗
PubMed1999

DRONC, an ecdysone-inducible Drosophila caspase.

Caspases play an essential role in the execution of programmed cell death in metazoans. Although 14 caspases are known in mammals, only a few have been described in other organisms. Here we describe the identification and characterization of a Drosophila caspase, DRONC, that contains an amino terminal caspase recruitment domain. Ectopic expression of DRONC in cultured cells resulted in apoptosis, which was inhibited by the caspase inhibitors p35 and MIHA. DRONC exhibited a substrate specificity similar to mammalian caspase-2. DRONC is ubiquitously expressed in Drosophila embryos during early stages of development. In late third instar larvae, dronc mRNA is dramatically up-regulated in salivary glands and midgut before histolysis of these tissues. Exposure of salivary glands and midgut isolated from second instar larvae to ecdysone resulted in a massive increase in dronc mRNA levels. These results suggest that DRONC is an effector of steroid-mediated apoptosis during insect metamorphosis.

3T3 Cells↗
PubMed1999

Laboratory medicine in Ontario: its downsizing and the consequences on quality.

Health care in Ontario consumes 35% of provincial government annual revenues. Fiscal constraint mandates restructuring of health services to maintain a fully, publicly-funded universally-accessible health system that is patient-focussed and health-outcome driven. Acute-care hospital restructuring under the authority of the Health Services Restructuring Commission and primary health-care reform characterise present government initiatives. Laboratory medicine services at about Can $1 billion annually account for about 5% of health expenditure. A Laboratory Services Restructuring Secretariat created by the Ministry of Health in 1995 has planned regionally-based integrated laboratory services systems bringing together public and private providers, designed a province-wide laboratory information system, developed a quality management program, reviewed the human resource needs for laboratory physicians, scientists and technologists, and recommended that the legislation be rewritten so as to be enabling - not controlling. Meanwhile both hospital and private laboratories have closed, leaving 296 in 1998 compared to 394 in 1991. Laboratory physician numbers at 39 per million population falls far short of the recommended target of 52 and many are within 10 years of retirement. Renewal of laboratory physicians and scientists to meet the shortfall is not occurring. The numbers of registered laboratory technologists has fallen by 6. 8% over 2 years. Consolidation and downsizing of laboratories with the formation of core laboratories has resulted in multi-discipline and cross discipline tasking of specialist technologists. Senior and middle level management technologists have been declared redundant. As a consequence, quality control practices have been hard hit. Plans to address these deficiencies through regional integration and sharing of resources remain to be implemented.

Clinical Laboratory Information Systems↗
PubMed1999

An overview of quality control practices in Ontario with particular reference to cholesterol analysis.

BACKGROUND: The Laboratory Proficiency Testing Program (LPTP) assesses the analytical performance of all licensed laboratories in Ontario. The LPTP Enzymes, Cardiac Markers, and Lipids Committee conducted a "Patterns of Practice" survey to assess the in-house quality control (QC) practices of laboratories in Ontario using cholesterol as the QC paradigm. DESIGN AND METHODS: The survey was questionnaire-based seeking information on statistical calculations, software rules, review process and data retention, and so on. Copies of the in-house cholesterol QC graphs were requested. A total of 120 of 210 laboratories were randomly chosen to receive the questionnaires during 1995 and 1996; 115 laboratories responded, although some did not answer all questions. RESULTS: The majority calculate means and standard deviations (SD) every month, using anywhere from 4 to >100 data points. 65% use a fixed mean and SD, while 17% use means calculated from the previous month. A few use a floating or cumulative mean. Some laboratories that do not use fixed means use a fixed SD. About 90% use some form of statistical quality control rules. The most common rules used to detect random error are 1(3s)/R4s while 2(2s)/4(1s)/10x are used for systematic errors. About 20% did not assay any QC at levels >5.5 mmol/L. CONCLUSIONS: Quality control data are reviewed daily (technologists), weekly and monthly (supervisors/directors). Most laboratories retain their QC records for up to 3 years on paper and magnetic media. On some QC graphs the mean and SD, QC product lot number, or reference to action logs are not apparent. Quality control practices in Ontario are, therefore, disappointing. Improvement is required in the use of clinically appropriate concentrations of QC material and documentation on QC graphs.

Chemistry, Clinical↗
PubMed1999

Nonisotopic detection and typing of human papillomavirus DNA in genital samples by the line blot assay. The Canadian Women's HIV study group.

The line blot assay, a gene amplification method that combines PCR with nonisotopic detection of amplified DNA, was evaluated for its ability to detect human papillomavirus (HPV) DNA in genital specimens. Processed samples were amplified with biotin-labeled primers for HPV detection (primers MY09, MY11, and HMB01) and for beta-globin detection (primers PC03 and PC04). Amplified DNA products were hybridized by a reverse blot method with oligonucleotide probe mixtures fixed on a strip that allowed the identification of 27 HPV genotypes. The line blot assay was compared to a standard consensus PCR test in which HPV amplicons were detected with radiolabeled probes in a dot blot assay. Two hundred fifty-five cervicovaginal lavage specimens and cervical scrapings were tested in parallel by both PCR tests. The line blot assay consistently detected 25 copies of HPV type 18 per run. The overall positivity for the DNA of HPV types detectable by both methods was 37.7% (96 of 255 samples) by the line blot assay, whereas it was 43. 5% (111 of 255 samples) by the standard consensus PCR assay. The sensitivity and specificity of the line blot assay reached 84.7% (94 of 111 samples) and 98.6% (142 of 144 samples), respectively. The agreement for HPV typing between the two PCR assays reached 83.9% (214 of 255 samples). Of the 37 samples with discrepant results, 33 (89%) were resolved by avoiding coamplification of beta-globin and modifying the amplification parameters. With these modifications, the line blot assay compared favorably to an assay that used radiolabeled probes. Its convenience allows the faster analysis of samples for large-scale epidemiological studies. Also, the increased probe spectrum in this single hybridization assay permits more complete type discrimination.

Cervix Uteri↗
PubMed1998

Analysis of a Drosophila cyclin E hypomorphic mutation suggests a novel role for cyclin E in cell proliferation control during eye imaginal disc development.

We have generated and characterized a Drosophila cyclin E hypomorphic mutation, DmcycEJP, that is homozygous viable and fertile, but results in adults with rough eyes. The mutation arose from an internal deletion of an existing P[w+lacZ] element inserted 14 kb upstream of the transcription start site of the DmcycE zygotic mRNA. The presence of this deleted P element, but not the P[w+lacZ] element from which it was derived, leads to a decreased level of DmcycE expression during eye imaginal disc development. Eye imaginal discs from DmcycEJP larvae contain fewer S phase cells, both anterior and posterior to the morphogenetic furrow. This results in adults with small rough eyes, largely due to insufficient numbers of pigment cells. Altering the dosage of the Drosophila cdk2 homolog, cdc2c, retinoblastoma, or p21(CIP1) homolog dacapo, which encode proteins known to physically interact with Cyclin E, modified the DmcycEJP rough eye phenotype as expected. Decreasing the dosage of the S phase transcription factor gene, dE2F, enhanced the DmcycEJP rough eye phenotype. Surprisingly, mutations in G2/M phase regulators cyclin A and string (cdc25), but not cyclin B1, B3, or cdc2, enhanced the DmcycEJP phenotype without affecting the number of cells entering S phase, but by decreasing the number of cells entering mitosis. Our analysis establishes the DmcycEJP allele as an excellent resource for searching for novel cyclin E genetic interactors. In addition, this analysis has identified cyclin A and string as DmcycEJP interactors, suggesting a novel role for cyclin E in the regulation of Cyclin A and String function during eye development.

Alleles↗
PubMed1998

decapentaplegic is required for arrest in G1 phase during Drosophila eye development.

During eye development in Drosophila, cell cycle progression is coordinated with differentiation. Prior to differentiation, cells arrest in G1 phase anterior to and within the morphogenetic furrow. We show that Decapentaplegic (Dpp), a TGF-&bgr; family member, is required to establish this G1 arrest, since Dpp-unresponsive cells located in the anterior half of the morphogenetic furrow show ectopic S phases and ectopic expression of the cell cycle regulators Cyclins A, E and B. Conversely, ubiquitous over-expression of Dpp in the eye imaginal disc transiently inhibits S phase without affecting Cyclin E or Cyclin A abundance. This Dpp-mediated inhibition of S phase occurs independently of the Cyclin A inhibitor Roughex and of the expression of Dacapo, a Cyclin E-Cdk2 inhibitor. Furthermore, Dpp-signaling genes interact genetically with a hypomorphic cyclin E allele. Taken together our results suggest that Dpp acts to induce G1 arrest in the anterior part of the morphogenetic furrow by a novel inhibitory mechanism. In addition, our results provide evidence for a Dpp-independent mechanism that acts in the posterior part of the morphogenetic furrow to maintain G1 arrest.

Animals↗
PubMed1998

Proficiency testing of creatine kinase and creatine kinase-2: the experience of the Ontario Laboratory Proficiency Testing Program.

The Ontario Laboratory Proficiency Testing Program has regularly monitored the analytical performance of total creatine kinase (CK) (approximately 230 participants) and CK isoenzyme-2 (CK-MB) (approximately 160 participants) throughout the entire province. Consistently, a wide dispersion of results has been observed not only between different analyzer systems but also among identical analyzers. Accordingly, the results of the last three proficiency surveys for these analytes were examined statistically to establish both the extent of these variations and the range of values reported for the male upper reference ranges. The results of many of the analyzer systems were significantly different from each other, as were many of the reference ranges. This unsatisfactory situation may only be remedied by the use of reference materials as shown by others. The consequences of these findings also effect the reliability of epidemiological surveys such as the WHO MONICA Project (Circulation 1994;90:583-612), which monitors deaths due to heart disease and includes cardiac enzyme results in its criteria.

Clinical Enzyme Tests↗
PubMed1996

Four Arabidopsis RPP loci controlling resistance to the Noco2 isolate of Peronospora parasitica map to regions known to contain other RPP recognition specificities.

Interactions between Arabidopsis thaliana and the downy mildew fungus Peronospora parasitica provide a model system to study the genetic and molecular basis of plant-pathogen recognition. With the use of the Noco2 isolate of P. parasitica, the reaction phenotypes of 46 accessions of Arabidopsis were examined and 31 accessions exhibited resistance. Resistance phenotypes examined ranged from distinct necrotic pits or flecks to a weak necrosis accompanied by late and sparse fungal sporulation. Segregating populations generated from crosses between the susceptible accession Col-0 and the resistant accessions Ws-0, Pr-0, Oy-0, Po-1, Bch-1, Ge-1, Di-1, Ji-1, and Te-0 were also screened with Noco2. The genetic data were consistent with the presence of single resistance (RPP) loci in all of these accessions except Oy-0, in which resistance was inherited as a digenic trait. As a first step to molecular cloning, the map positions of four resistance loci were determined. These have been designated RPP14.1 from Ws-0, RPP14.2 from Pr-O, and RPP14.3 and RPP5.2 from Oy-0. RPP14.1 was mapped to a 3.2-cM interval on chromosome 3 that is linked to a region between the markers Gl-1 and m249 known to contain other P. parasitica resistance specificities. RPP14.2 from Pr-0 and RPP14.3 from Oy-0 were also positioned in this interval. Moreover, RPP14.1 and RPP14.2 showed linkage of < 0.05 cM, suggesting possible allelism. The second RPP locus from Oy-0, RPP5.2, was located on chromosome 4 and exhibited strong linkage (< 2 cM) to RRP5.1, a locus previously identified in the Arabidopsis accession Landsberg-erecta. The results reinforce evidence for RPP gene clustering in the Arabidopsis genome and provide new targets for cloning and examination of RPP gene structure, function, allelic variation, and organization within defined loci.

Alleles↗
PubMed1996

A natural survey of audit activity across the primary-secondary care interface.

OBJECTIVE: To document the nature of audit activity at the primary-secondary care interface; to explore participants' experiences of undertaking such interface audit; to identify factors associated with these experiences; and to gather views on future interface audit activities. DESIGN: A three phase national survey by postal questionnaire with a cascade sampling approach. SETTING: England and Wales. RESULTS: Response rates were: 65% to the first questionnaire; 34% to the second questionnaire; and 45% to the third questionnaire. 56% of the audits covered some element of management of patients or disease; only 33% of the audits were within a single topic area. Most audits had more than one trigger: for 61% the trigger was a perceived problem; for 58% it was of mutual interest. Only 18% of audits were initiated collaboratively; doctors were the most frequent initiators (72%), and most audits (63%) involved collaborative groups convened specifically for the audit. 58% of groups had between three and eight members, 23% had 12 or more. Doctors were the most frequent group members. There was differential involvement of group members in various group tasks; the setting of guidelines was highly dominated by doctors. Of reportedly complete audits, only two fifths had implemented change and only a quarter had evaluated this change. There was widespread feeling of successful group work, with evidence of benefit in terms of the two sectors of care being able to consider issues of mutual concern. Levels of understanding of the group task and of participation were positively related to the duration of meetings. Joint initiation of audits facilitated greater understanding of the group task. Larger group sizes allowed primary and secondary carers to discuss issues of common concern; however, larger groups were more likely to experience disagreements. Having previously worked with group members increased trust and good working relations. The main lessons learnt from the experience included the importance of setting clear objectives and good communications between primary and secondary carers. Factors identified as important for future audit activity at the primary-secondary care interface included commitment, enthusiasm, time, and money. CONCLUSIONS: Audit at the primary-secondary care interface is taking place on a wide scale and has been an enjoyable experience for most of the respondents in this study. IMPLICATIONS: Despite being a positive experience most audits stopped short of implementing change. Care must be taken to complete the audit cycle if audit at the primary-secondary care interface is to move beyond the roles of education and professional development and to fulfil its potential in improving the quality of care.

England↗