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Biomedical subjects

J Morrison

Publications and source records attributed to J Morrison.

At least 55 records · Page 3Linked to original sources
PubMed2000

Transcription mapping and expression analysis of candidate genes in the vicinity of the mouse Loop-tail mutation.

Loop-tail (Lp) is a semidominant mutation that maps to the distal portion of mouse Chromosome (Chr) 1 and is an established model for neural tube defects (NTDs). Homozygous embryos exhibit an open neural tube from the caudal midbrain to the tip of the tail that results from over-differentiation of the floor plate. To facilitate the positional cloning of the Lp gene, both cDNA selection and assignment of sequence-tagged-sites from the human transcript map have been used to identify genes within the Lp interval. Together with previous physical mapping, this has allowed the placement of 13 transcription units within an approximately 1-Mb region that spans the Lp genetic interval, and eight of these genes map to the nonrecombinant interval. This map includes genes that encode proteins involved in protein sorting and targeting (Tim23 and Copa), ion transport (Atp1a2, Atp1a4, and Girk3), transcription (Nhlh1), immune regulation (Cd48 and Fcer1alpha), cell adhesion (R88252), apoptosis (Pea15), and several of unknown function (H326, Kiaa0253, and Estm34). Expression analysis by Northern blotting indicated that a subset of these genes are expressed preferentially in the developing nervous system. Finally, this region of mouse Chr 1 represents a conserved linkage group with genes on human chromosome 1q21, a region that is frequently altered in human cancers and that harbors loci for several genetic conditions. Consequently, analysis of the Lp interval may provide important tools to understand how the corresponding region of human Chr 1 contributes to disease, in addition to defining a key gene product required for neurulation.

Animals↗
PubMed2000

T-cell-dependent fibrosis in the mdx dystrophic mouse.

In Duchenne muscular dystrophy patients, the pathological hallmark of the disease, namely, the chronic accumulation of sclerotic scar tissue in the interstitial space of skeletal muscle is attributed to manifestation of secondary pathological processes. Such anomalous generation of matrix protein is thought to be driven by the continuous degeneration and regeneration of muscle both in Duchenne Muscular Dystrophy and in the mdx mouse homolog. We examined mdx and the control strain C57bl/10 mice over a range of ages with respect to the amounts of collagen present in muscles and other organs, finding that the mdx have significantly higher collagen content at later time points in their kidney and lung as well as their muscles. Surprisingly, when we bred the mdx mice on the nu/nu background, the time course of fibrogenesis was modified depending on the tissue and the collagen content was significantly different in age-matched mice. Transplantation of normal thymic tissue into the mdx-nu/nu mice replenished their T-cells and concomitantly altered the collagen content in their tissues to levels comparable with those in immunocompetent mdx mice. This suggests that T-cells play a role in the onset of the fibrotic events that undermines the ability of dystrophic muscle to regenerate.

Aging↗
PubMed2000

A process evaluation of medical ethics education in the first year of a new medical curriculum.

BACKGROUND: Despite the recent increase in activity in the field of medical ethics education, few evaluative studies have been carried out. Most studies have taken place in North America, in curricula where teaching is discipline-based, and have concentrated on outcome rather than on the curricular processes adopted. AIM: To evaluate the process of medical ethics education in the first year of a new learner-centred, problem-based, integrated medical curriculum. METHOD: A qualitative, multi-method approach was adopted using open questionnaires, focus groups and tutor evaluation rating scales. The study involved all 238 students in the first year of the new medical curriculum, and the 30 clinical tutors who facilitated ethics learning. A stratified sampling technique was used to choose focus group participants. RESULTS: Small group teaching proved highly acceptable to both students and tutors. Tutors' teaching skills were central to its effectiveness. Tutors played an important role in promoting students' appreciation of the relevance of medical ethics to clinical practice, and in establishing a climate where constructive criticism of colleagues' actions is acceptable. Course integration, including the provision for students of clinical experiences on which to reflect, was an important aid to learning. Students and tutors were noted to be driving the ethics curriculum towards having a contextual rather than theoretical base. CONCLUSION: This evaluation identified those aspects of the medical ethics course which contributed to its effectiveness and those which detracted from it. This information will be used to inform future development.

Curriculum↗
PubMed2000

Audit of anti-D immunoglobulin administration to pregnant Rhesus D negative women following sensitising events.

We performed a retrospective audit of 99 Rhesus D (RhD) negative women to discover if anti-D immunoglobulin (anti-D) prophylaxis was given in accordance with guidelines from the National Blood Transfusion Service Immunoglobulin Working Party (1991). It was found that all patients received appropriate management postpartum. However, more than half of the antepartum sensitising events beyond 20 weeks' gestation were not managed according to the guidelines. Only one patient was sensitised during the studied pregnancy and no sensitising events were recorded in her case. This supports the introduction of a policy of routine anti-D prophylaxis in the third trimester.

Journal Article↗
PubMed2000

Bioactive transforming growth factor-beta in the lungs of extremely low birthweight neonates predicts the need for home oxygen supplementation.

Transforming growth factor-beta (TGF-beta) is a peptide implicated in tissue injury and repair but its role in the premature human lung remains unclear. In the present study, we used a TGF-beta responsive-promoter-luciferase construct in mink lung epithelial cells to quantify levels of biologically active TGF-beta (BA-TGF-beta) in the endotracheal aspirate (ETA) fluid from 16 extremely low birthweight neonates [6 M/10 F, mean GA 26 weeks (range 23-30), mean BW 774 g (range 555-1,075)]. ETA fluid was obtained on day 1 and then every 4 days up to 32 days. BA-TGF-beta levels were low (92 +/- 19 pg/ml) in the first 24 h of life and then increased 5- to 10-fold with peak BA-TGF-beta levels (400 +/- 50 pg/ml) on day 20-25. BA-TGF-beta levels were higher in male than female infants (p = 0.0056). Prenatal steroids decreased significantly the amount of BA-TGF-beta recovered. High initial levels of BA-TGF-beta persisted over time and were predictive of the need for oxygen therapy at home. We conclude that abundant BA- TGF-beta is present in the lungs of preterm infants and speculate that it may be involved in inflammatory and repair processes encountered in acute and chronic lung disease.

Bronchoalveolar Lavage Fluid↗
PubMed2000

Regional differences in cardiovascular mortality in Minnesota.

Cardiovascular disease is the leading cause of death in the United States. Initial results from our health survey in the Red River Valley of Minnesota suggested elevated cardiovascular mortality in men and women in younger age groups there compared with the rest of the state. Similarly, earlier published longitudinal studies of cardiovascular mortality in Minnesota revealed increased cardiovascular mortality in counties west of a diagonal line drawn through the tip of the arrowhead region (northeast Minnesota) to the southwest corner of the state. In this study we examined cardiovascular mortality by geographic region with respect to economic factors, residence patterns, and ethnic group. Since these regions vary in geology and major land use, environmental factors were considered as well. Our present data show a significant elevation in cardiovascular mortality from 1987-1997 in men and women aged 25-59 in northwest and northeast Minnesota counties compared with central-metro counties. In contrast, south-central Minnesota shows a rate of cardiovascular mortality for that age group similar to that seen in the central-metro region. The increase in cardiovascular deaths from myocardial infarct in the younger groups in the more rural, less affluent areas of northwest Minnesota is nearly two times higher than in the central-metro counties. Genetic factors may play a role in the increased mortality recorded for northeast Minnesota. Environmental contaminants such as pesticides are additional considerations. Finally, our data suggest the need to address long-standing regional cardiovascular mortality differences and rural health care access in Minnesota.

Adult↗
PubMed1999

Exclusion of linkage of Shwachman-Diamond syndrome to chromosome regions 6q and 12q implicated by a de novo translocation.

Shwachman-Diamond syndrome is a rare genetic disorder of unknown pathogenesis involving exocrine pancreatic insufficiency and hematological and skeletal abnormalities. There is broad clinical variability; the extent of heterogeneity is unknown but comparisons within a large cohort of patients show no striking differences between patients of families with single or multiple affected offspring. Segregation analysis of a cohort of 69 families has suggested an autosomal recessive mode of inheritance. A single constitutional de novo chromosome rearrangement was reported in a Japanese patient involving a balanced translocation, t(6;12)(q16.2;q21.2), thereby suggesting possible loci for a genetic defect. Evenly spaced microsatellite markers spanning 26-32 cM intervals from D6S1056 to D6S304 and D12S375 to D12S346 were analyzed for linkage in members of 13 Shwachman-Diamond syndrome families with two or three affected children. Two-point lod scores were calculated for each marker under assumptions of recessive inheritance and complete penetrance. Negative lod scores indicated exclusion of both chromosome regions. Further, affected sibs were discordant for inheritance of chromosomes in most families based on constructed haplotypes. The cytogenetic abnormality is not associated with most cases of Shwachman-Diamond syndrome.

Bone and Bones↗
PubMed1999

Terbutaline.

Explore the source record for details and available documents.

Female↗
PubMed1999

Shwachman syndrome: phenotypic manifestations of sibling sets and isolated cases in a large patient cohort are similar.

OBJECTIVES: With the use of clinical data from a large international cohort, we evaluated and compared affected siblings and isolated cases. STUDY DESIGN: Data from 116 families were collected, and patients conforming to our predetermined diagnostic criteria were analyzed. Phenotypic manifestations of affected siblings and singletons were compared with the use of t tests, Wilcoxon scores, and chi2 analysis. RESULTS: Eighty-eight patients (33 female, 55 male; median age 5.20 years) fulfilled our predetermined diagnostic criteria for Shwachman syndrome; 63 patients were isolated cases, and 25 affected siblings were from 12 multiplex families. Steatorrhea was present in 86% (57 of 66), and 91% (78 of 86) displayed a low serum trypsinogen concentration. Patients older than 4 years more often had pancreatic sufficiency. Neutropenia occurred in 98%, anemia in 42%, and thrombocytopenia in 34%. Myelodysplasia or cytogenetic abnormalities were reported in 7 patients. Short stature with normal nutritional status was a prominent feature. CONCLUSIONS: Clinical features among patients with Shwachman syndrome varied between patients and with age. Similarities in phenotype between isolated cases and affected sibling sets support the hypothesis that Shwachman syndrome is a single disease entity.

Bacterial Infections↗
PubMed1999

Rationing decisions: from diversity to consensus.

As rationing decisions become more of an immediate reality for healthcare practitioners it is important to design mechanisms that facilitate carefully deliberated outcomes. No individual can be expected to be able to cover wide debate on their own, so an exercise has been designed that helps generate consensus decisions from diverse opinions. The exercise was piloted with two groups, an undergraduate medical class and the members of a general practice. Though the aims were different for each group, the tool was useful to both for producing the desired outcomes. Expert and non-expert knowledge were drawn upon and rationing prioritisation lists regarding funding of infertility treatment were generated. A description of the exercise and the results produced by the two groups are provided, as well as the theoretical placement for the significance of forming consensus from diversity.

Consensus↗
PubMed1999

Role of postnatal penicillin prophylaxis in prevention of neonatal group B streptococcus infection.

This prospective study was designed to identify the role of postnatal penicillin prophylaxis in the prevention of neonatal group B streptococcus (GBS) infection. We studied 10 998 infants. Of these, 5389 were in the penicillin prophylaxis group (PP) and 5609 infants did not receive penicillin prophylaxis (NPP). Infants were allocated to treatment by month of birth, alternating 3-mo blocks or 2-mo blocks to the two groups after the first block was randomly assigned. The use of PP reduced the incidence of clinical sepsis (1.7% PP versus 2.5% NPP, p < 0.01), GBS infection (0.4% PP versus 0.9% NPP, p < 0.001) and deaths from sepsis (0.1% PP versus 0.3% NPP, p < 0.05). We conclude that the routine use of postnatal penicillin prophylaxis appears to be effective in reducing the incidence of clinical sepsis and death from sepsis in neonates.

Antibiotic Prophylaxis↗
PubMed1999

Genome-wide screen for systemic lupus erythematosus susceptibility genes in multiplex families.

Systemic lupus erythematosus (SLE) is the prototype of human autoimmune diseases. Its genetic component has been suggested by familial aggregation (lambdas = 20) and twin studies. We have screened the human genome to localize genetic intervals that may contain lupus susceptibility loci in a sample of 188 lupus patients belonging to 80 lupus families with two or more affected relatives per family using the ABI Prism linkage mapping set which includes 350 polymorphic markers with an average spacing of 12 cM. Non-parametric multipoint linkage analysis suggests evidence for predisposing loci on chromosomes 1 and 18. However, no single locus with overwhelming evidence for linkage was found, suggesting that there are no 'major' susceptibility genes segregating in families with SLE, and that the genetic etiology is more likely to result from the action of several genes of moderate effect. Furthermore, the support for a gene in the 1q44 region as well as in the 1p36 region is clearly found only in the Mexican American families with SLE but not in families of Caucasian ethnicity, suggesting that consideration of each ethnic group separately is crucial.

Chromosomes, Human, Pair 1↗
PubMed1999

Out-patient parenteral antimicrobial therapy--a viable option for the management of cutaneous leishmaniasis.

Cutaneous infection with Leishmania braziliensis complex requires treatment with parenteral pentavalent antimonials to prevent development of mucocutaneous leishmaniasis. Patients with imported disease are usually managed in hospital because of concerns over drug toxicity. This study describes the clinical features and outcome of infection treated in the UK in an out-patient setting. Thirteen marines (aged 19-35 years) who acquired leishmaniasis in Belize were studied prospectively. Three had at least two lesions (0. 6-3 cm diameter), eight had regional lymphadenopathy and one had localized painless lymphatic thickening. Histology for amastigotes and PCR for Leishmania braziliensis complex was positive in all. Culture was positive in six. Patients received 1.5-2 g (mean 1.7 g) (20 mg/kg) sodium stibogluconate intravenously daily for 20 days. All developed transient musculoskeletal symptoms and asymptomatic hepatitis. Eleven developed biochemical pancreatitis, and one thrombocytopenia. Three developed transient ECG changes and one herpes zoster. There were four device-related infections, two requiring hospitalization (one required surgical drainage of an abscess). All lesions re-epithelialized. A total of 250 bed-days were saved over a 67-day period. These results indicate that in selected patients, out-patient therapy for cutaneous leishmaniasis with parenteral high-dose sodium stibogluconate may be appropriate, provided there is adequate monitoring of therapy.

Adult↗