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Biomedical subjects

K Hogan

Publications and source records attributed to K Hogan.

At least 37 records · Page 2Linked to original sources

Genotype-phenotype correlations of DHP receptor alpha 1-subunit gene mutations causing hypokalemic periodic paralysis.

Hypokalemic periodic paralysis (hypoKPP) is an autosomal dominant or sporadic disorder characterized by periodic, reversible attacks of muscle weakness. Mutations in the skeletal muscle dihydropyridine receptor alpha 1-subunit that functions as a calcium channel (CACNL1A3) cause hypoKPP. We studied a group of 45 hypoKPP probands and demonstrated mutations in 30 of them. When compared with patients in whom CACNL1A3 mutations were not identified, those with mutations had an earlier age of onset and more often had a family history of hypoKPP. To date, three mutations have been identified. The R1239G mutation has only been found in one family. Of the 30 probands with recognized mutations, R528H accounted for 43% and R1239H was seen in 53%. Age of onset and potassium levels during attacks were lower in patients with the R1239H mutation than those with R528H. Cardiac dysrhythmias co-segregated with hypoKPP in one small kindred with the R528H mutation. No mutations were identified in exons of the gene encoding the S4 segments of domains one and three or the cytoplasmic loop between domains two and three. In addition to the 45 hypoKPP probands, an additional 11 probands with clinical variants of hypoKPP (three thyrotoxic hypoKPP and eight Andersen syndrome patients) were examined for CACNL1A3 mutations and none were found.

Adolescent↗

Polysome-associated mRNAs are substrates for the nonsense-mediated mRNA decay pathway in Saccharomyces cerevisiae.

In eukaryotic cells, premature termination of translation at nonsense codons has been implicated as the cause of a variety of posttranscriptional events, including rapid mRNA decay in the cytoplasm or the nucleus, altered splice site selection, and exon skipping. In the yeast Saccharomyces cerevisiae, nonsense codons promote accelerated mRNA decay, and we sought to determine the cellular location in which this degradation occurs. In this report, we demonstrate that six different mRNAs, including nonsense-containing transcripts of the LEU2, HIS4, PGK1, and CYH2 genes, and two wild-type mRNAs (the MAT(alpha)1 and CYH2 mRNAs), were stabilized when the translation elongation inhibitor cycloheximide was added to cellular growth media. Subsequent removal of cycloheximide resulted in resumption of translation and degradation of wild-type and nonsense-containing mRNAs. A significant fraction of the CYH2 pre-mRNA that accumulated in the presence of cycloheximide was associated with polysomes, but disappeared from that fraction when decay resumed in the absence of the drug. Moreover, the abundance of the spliced and unspliced forms of the untranslated U3 snRNA was shown to be unaffected in strains harboring mutations that stabilize nonsense-containing mRNAs. Taken together, these observations indicate that nonsense-containing mRNAs in yeast are degraded within the polysome compartment of the cell.

Codon, Nonsense↗

Hospital-based patient information services: a model for collaboration.

Crouse Hospital in Syracuse, New York, is a 612-bed, not-for-profit teaching hospital with 2,500 employees. A close examination of operations at Crouse facilitated the development of a patient education task force that used a comprehensive, multidisciplinary approach to meet the educational needs of both patients and clinicians. The collaborative process involved all hospital departments. Within eighteen months, patient requests for information rose from 3% to 30% of total requests made at the hospital. Requests were made directly to the library or through a member of the health care team. Hospital staff members were surveyed about information needs and availability, and a library work plan was devised, setting standards of service for a multimedia approach. Work redesign improved the library staff's ability to integrate patient education into daily operations. Cost savings were achieved through the elimination of duplicated resources and services throughout the hospital. The management model developed at Crouse was the result of a needs assessment and a multidisciplinary, collaborative process. The model emphasizes communication links among disciplines rather than physical locations. The Crouse experience validates the development of hospital-based consumer health information services.

Attitude of Health Personnel↗

Prevalence of HIV infection among pregnant women in Newfoundland.

OBJECTIVE: To determine the prevalence of HIV infection among pregnant women in Newfoundland. DESIGN: Anonymous unlinked seroprevalence study. SETTING: Newfoundland. PATIENTS: A total of 14911 women receiving prenatal care or undergoing an abortion, representing nearly all pregnancies in Newfoundland from Nov. 1, 1991, to Oct. 31, 1993. OUTCOME MEASURES: HIV antibody status, as determined by enzyme immunoassay of leftover serum samples (initially obtained for routine screening) and confirmation of reactive samples by the Western blot technique, health region of residence, and age group. RESULTS: Of the 14911 serum samples 13 were positive for HIV, for an overall crude prevalence rate of 1 per 1147 or 8.7 per 10000 pregnant women (95% confidence interval [CI] 4.7 to 14.9). Seven of the positive samples were from women residing in the Eastern Health Region of the province, for a crude prevalence rate of 1 per 376 or 26.6 per 10000 pregnant women (95% CI 10.7 to 54.8) for that region. All women found to be HIV positive were 15 to 29 years of age, the peak prevalence (20.8 per 10000 pregnant women [95% CI 9.5 to 39.4]) was observed among those 20 to 24 years. CONCLUSIONS: The overall prevalence rate of 8.7 per 10 000 pregnant women in Newfoundland is the highest provincial rate recorded among those from similar studies in Canada. Although it may be concluded that there are an estimated 125 HIV-positive women of childbearing age in Newfoundland (95% CI 67 to 213), the age-adjusted estimate is 84 (95% CI 36 to 131). This study provides an independent confirmation of an outbreak of HIV infection among women in the Eastern Health Region of the province.

Adolescent↗

The structure of the gene encoding the human skeletal muscle alpha 1 subunit of the dihydropyridine-sensitive L-type calcium channel (CACNL1A3).

The structure of the gene encoding the human skeletal muscle alpha 1 subunit (CACNL1A3) of the dihydropyridine-sensitive voltage-dependent calcium channel was determined by isolation of overlapping genomic DNA clones from human cosmid, phage, and P1 libraries. Genomic fragments containing exons were subcloned, and the sequences of the exons and flanking introns were defined. Knowledge of the genomic structure of the CACNL1A3 gene, which spans 90 kb and consists of 44 exons, will facilitate the search for additional mutations in CACNL1A3 that cause neuromuscular disease.

Base Sequence↗

Brief report: two case studies using virtual reality as a learning tool for autistic children.

The children complied with most requests. Some of our teaching goals were limited by technology or space while others were limited by the difficulty of presenting a task to the children in a way that was understandable within their environment. However, the opportunity to introduce this technology to children was an important first step in exploring the potential VR offers to understanding the perceptual processes involved in autism. Our results indicate that the will accept a VR helmet and wear it, identify familiar objects and qualities of these objects in their environment while using the helmet, and locate and move toward objects in their environment while wearing the helmet. More research is necessary to verify the potential in this area, especially to discover if learning experiences through VR generalize to other environments, but it appears virtual reality may provide a useful tool for furthering our understanding of autism and guiding efforts at treatment and intervention.

Autistic Disorder↗

The assessment of student nurse learning styles using the Kolb Learning Styles Inventory.

The learning styles of 192 Registered General Nursing/DipHE students was determined using the Kolb Learning Styles Inventory prior to the students having any formal contact with lecturing staff. The percentage of students having a predominantly concrete learning style was 53.7%, while 46.3% were predominantly reflective. This finding is in keeping with those of Laschinger & Boss (1984), who suggest that they are supportive of Kolb's theoretical tenet that concrete learners tend to choose people-oriented professions. Chi-squared tests were used to determine if the respondent's learning styles varied with either age, sex or having been in employment prior to becoming a nursing student; no statistically significant associations were found. A further chi-squared analysis was performed to see if there was a relationship between learning style and those students who possessed: 1) only the DC test, 2) O-levels as highest qualifications, and 3) A-levels as highest qualifications--no statistically significant associations were found. There remain measurement problems with the Kolb inventory, and a discussion of some of these issues are presented. The findings have reinforced the need for using a variety of delivery styles with students, with an emphasis on participation and experiential learning. This need for variety is essential given the distribution of learning styles found with the students. Nurse educators are urged to re-examine perceptions and assumptions about student learning needs.

Adolescent↗

Self-measurement of blood pressure: issues related to the training of patients. Canadian Coalition for High Blood Pressure Prevention and Control.

For effective self-measurement of blood pressure, patients need to be able to obtain accurate and reproducible measurements. Criteria for measuring blood pressure have been well developed in research studies, and through the use of standardized training programs it has been established that nonmedically trained individuals can obtain valid measurements. These recommendations for blood pressure measurement were adapted to the self-measurement situation. Either manual sphygmomanometers or automated electronic devices can be used effectively. Although automated devices may be easier to use, the health care practitioner should ensure that any such device has been demonstrated to be accurate and reliable before its adoption. There are no reported programs available for training individuals in the use of self-measurement. A check-list has been developed for use by health care practitioners. It is estimated that proper training will usually take more than 20 mins. Since many health care practitioners do not use the recommended blood pressure measurement technique, there is also a need to develop programs to 'train the trainers'. Finally, individuals undertaking regular self-measurement should have their technique and the calibration of their instruments checked at regular intervals (six to 12 months).

Blood Pressure Determination↗

Self-measurement of blood pressure: recommendations of the Canadian Coalition for High Blood Pressure Prevention and Control.

OBJECTIVE: To provide health care professionals with guidelines on the use of blood pressure self-measurement. METHODS: Recommendations were devised after consideration of expert reviews and guidelines, personal files, international standards documents, personal communication with investigators and the results of a MEDLINE search (1966-94) using the term 'blood pressure determination'. BENEFITS, HARMS, COSTS: Self-measurement of blood pressure can be used to detect white coat hypertension, monitor changes in blood pressure closely, more rapidly achieve desired blood pressure goals, increase adherence to antihypertensive therapy and improve patient self-reliance. However, self-measured blood pressure readings may be misleading because there is insufficient normative, prognostic and outcome data and because some patients may not take accurate measurements. The use of self-measurement of blood pressure has a relatively small direct cost and may result in an overall reduction in treatment costs. RECOMMENDATIONS: Self-measured blood pressure readings can be a valuable supplement to clinic (or office) blood pressure readings. However, self-measurement is appropriate neither for patients who are physically or mentally incapable of accurate assessment and interpretation of readings nor for those who do not want to participate. Patients who self-monitor blood pressure require careful training in blood pressure measurement and instruction on the recording and interpretation of blood pressure readings. Advice to patients using monitoring equipment must take into account the needs and abilities of the patient. Although only a few electronic devices for the self-measurement of blood pressure have met recommended performance standards, their use may be more appropriate for some patients and the training requirements fewer than if manual devices are used. VALIDATION: The guidelines of several expert groups were examined in the preparation of these recommendations. The recommendations were presented at the World Conference on Hypertension Control in 1995 and were reviewed by the parent societies of the Canadian Coalition for High Blood Pressure Prevention and Control.

Blood Pressure Determination↗