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Biomedical subjects

M Nelson

Publications and source records attributed to M Nelson.

At least 19 recordsLinked to original sources
PubMed1995

Familial inverted duplication 7p.

A 10-month-old female with developmental delay and failure to thrive was referred for genetic evaluation as part of an adoption assessment. Physical exam showed a mildly beaked nose and clinodactyly, but otherwise nothing remarkable. Chromosome analysis showed an inverted duplication of the p12.2-->p13 portion of chromosome 7[(46,XX, dup(7)(p13p12.2)]. The proposita's older brother, mother, and grandmother were cognitively delayed and had the same chromosome 7 duplication. A review of the literature showed no other cases involving this exact duplication.

Chromosome Inversion↗
PubMed1995

Matching versus cultural competence in research: methodological considerations.

Researcher/participant matching has been used in nursing research as a strategy for the development of culturally competent knowledge. In this manuscript, the complexities inherent in matching in nursing research are discussed. In raising and discussing issues and questions related to matching, we argue that although matching may be one of the strategies used to generate culturally competent knowledge, it is frequently too complex for operationalization. Therefore, we propose that researchers reflect on questions related to their knowledge of culture, their cultural sensitivity, and the nature of collaboration during every phase of the research. Reflecting on and responding to these questions in every research project may facilitate the development of more culturally competent knowledge.

Cultural Diversity↗
PubMed1995

Randomized double-blind comparison of the analgesic efficacy of intramuscular ketorolac and oral indomethacin in the treatment of acute gouty arthritis.

STUDY OBJECTIVE: To compare the analgesic effect of IM ketorolac tromethamine with that of oral indomethacin in the treatment of acute gouty arthritis. DESIGN: Prospective, randomized, double-blind, controlled, parallel group clinical trial. SETTING: Two urban emergency departments. PARTICIPANTS: Twenty consecutive patients who presented to the ED with acute gout. INTERVENTIONS: Each patient was randomly assigned to receive in the ED (1) 60 mg of IM ketorolac and oral placebo or (2) 50 mg of oral indomethacin and IM placebo. The patients rated the intensity of their pain on a Wong-Baker pain scale (which runs from 0 to 5) before treatment and 30, 60, 90, and 120 minutes after treatment. All the patients were discharged with instructions to take oral indomethacin and to complete pain score cards at home at 6, 12, and 24 hours. RESULTS: The 10 patients in each group were similar with regard to age, sex, race, and initial mean pain score. After 2 hours, the mean pain scores (+/- SD) for the ketorolac group had decreased from 4.5 +/- .71 to 1.4 +/- 1.43 (P < .05), and the mean score for the indomethacin group had decreased from 4.4 +/- .70 to 1.5 +/- 1.18 (P < .05). The difference between the two groups was not significant. At 6 hours, there was some pain rebound in the ketorolac group. CONCLUSION: IM ketorolac and oral indomethacin are similar in the relief of the pain of acute gouty arthritis in the ED.

Administration, Oral↗
PubMed1995

Teaching Spanish to emergency medicine residents.

OBJECTIVE: To determine the effects of teaching medical Spanish to eight PGY1 emergency medicine residents on their subsequent interactions with Spanish-speaking patients. METHODS: Eight PGY1 residents completed a 45-hour medical Spanish course administered during their first residency month. Thirty-four subsequent physician-patient interactions by these residents were audiotaped over a six-month period at a suburban teaching ED. The tapes were transcribed and analyzed for errors by a professional medical Spanish interpreter and a native Spanish speaker. RESULTS: Minor errors (e.g., technically incorrect grammar or vocabulary with generally appropriate patient understanding) were found in more than half of the interactions and major errors (e.g., misunderstanding duration of symptoms, misunderstanding of vocabulary) were found in 14% of the interactions. In addition, although the course was designed to supplement, not replace, professional interpreters, the residents called for an interpreter only 46% of the time. CONCLUSION: Although medical language courses may be a useful adjunct to interpreters, they are not designed to replace them. Significant errors may occur when participants in such courses assume their knowledge is sufficient to obtain a good history, give patient release instructions, and provide medical care in general without an interpreter present.

Adolescent↗
PubMed1992

TonB-independent ferrioxamine B-mediated iron transport in Escherichia coli K12.

The TonB protein of Escherichia coli K12 couples the energized state of the cytoplasmic membrane with energy-dependent receptors in the outer membrane. High affinity iron transport mediated by ferric dicitrate, ferrienterobactin, ferriaerobactin, ferrichrome, and coprogen all require a functional tonB protein. However, we have found no difference between the growth rates of tonB+ strains and tonB strains using ferrioxamine B as the sole iron source. This TonB-independence of FOB transport and earlier results with a photoactive FOB analog indicate a separate mechanism for iron acquisition from FOB in E. coli.

Bacterial Proteins↗
PubMed1992

Characterization of Chlorella virus PBCV-1 CviAII restriction and modification system.

A second DNA site-specific (restriction) endonuclease (R.CviAII) and its cognate adenine DNA methyltransferase (M.CviAII) were isolated from virus PBCV-1 infected Chlorella strain NC64A cells. R.CviAII, a heteroschizomer of the bacterial restriction endonuclease NlaIII, recognizes the sequence CATG, and does not cleave CmATG sequences. However, unlike NlaIII, which cleaves after the G and does not cleave either CmATG or mCATG sequences, CviAII cleaves between the C and A and is unaffected by mCATG methylation. The M.CviAII and R.CviAII genes were cloned and their DNA sequences were determined. These genes are tandemly arranged head-to-tail such that the TAA termination codon of the M.CviAII methyltransferase gene overlaps the ATG translational start site of R.CviAII endonuclease. R.CviAII is the first chlorella virus site-specific endonuclease gene to be cloned and sequenced.

Amino Acid Sequence↗
PubMed1992

Autoantibodies to thrombomodulin: development of an enzyme immunoassay and a survey of their frequency in patients with the lupus anticoagulant.

In order to investigate the possibility that autoantibodies to thrombomodulin (TM) may exist in patients with the lupus anticoagulant (LA) and perhaps be implicated in the pathogenesis of recurrent thrombosis seen in such patients, we developed an enzyme-immunoassay to screen serum samples for anti-human TM activity. The major technical problem encountered in developing this assay was to reduce the non-specific binding of serum components from both the LA positive and the negative population. Considerable reduction of non-specific binding was achieved by use of a phosphate/citrate buffer at pH 8.0 and the use of an optimal sample dilution of 1/40. In addition, samples were always tested in parallel in blank wells and results are expressed as an OD ratio. Samples from 113 patients with the LA were assayed and compared to 78 patients referred for LA testing but found to be negative. The mean OD values for the LA positive patients (+/- SD) was 1.36 (0.44) with a range of 0.78-2.57. This was virtually identical to the values for the LA negative population (1.38 +/- 0.40, range 0.76-2.77). The results of this study indicate that there is no evidence for the presence of a significant autoantibody activity to TM in patients with the LA when compared to LA negative patients. If such autoantibodies do exist their frequency must be quite low.

Autoantibodies↗
PubMed1992

A single amino acid change restores DNA cytosine methyltransferase activity in a cloned chlorella virus pseudogene.

The chlorella virus PBCV-1 contains an open reading frame, named P17-ORF4, which differs by eight amino acids from a DNA cytosine methyltransferase, M.CviJI, encoded by a different chlorella virus IL-3A. Whereas IL-3A expresses M.CviJI, which methylates the central cytosine in (A/G)GC(T/C/G) sequences, P17-ORF4 is non-functional. Gene fusions between P17-ORF4 and M.CviJI and site-directed point mutations revealed that changing Gln188 to Lys188 abolishes M.CviJI methyltransferase activity. Conversely, changing Lys188 in P17-ORF4 to Gln188 results in M.CviJI activity. The other altered seven amino acids do not appear to affect M.CviJI activity.

Amino Acid Sequence↗
PubMed1992

DNA sequencing of four bases using three lanes.

A three-lane DNA sequencing strategy is described which is based on redundant binary coding principles from communications theory. Three-lane sequencing is an efficient, accurate, and flexible strategy, suitable for large-scale automated DNA sequencing. Communications theory and algebraic coding principles can also be applied to sequencing other informational macromolecules.

Base Composition↗
PubMed1992

Choroid plexus tumors in childhood. Response to chemotherapy, and immunophenotypic profile using a panel of monoclonal antibodies.

Clinical and immunophenotypic (IP) data are presented on three children with choroid plexus (CP) tumors. Two children ages 0.2 and 2 years old with histologically proven malignant tumors had subtotal tumor resections and were treated with ten monthly cycles of eight-drugs-in-1-day chemotherapy without radiation therapy (XRT). Both are free of tumor 4 and 7 years later. The literature on survival of children with CP carcinomas after chemotherapy and XRT is reviewed. Monoclonal antibodies to 17 neuroectodermal, neuronal, glial, and leukocytic markers on frozen sections were used to IP the two malignant tumors and a CP papilloma. All tumors expressed two neuroectodermal markers (PI-153/3 and UJ 223.8), cytokeratin 19, and a neural and leukocyte marker (Thy-1). Two of three expressed neurofilament protein (NF-H) and glial fibrillary acidic protein (GFAP) and one expressed NF-M and common leukocyte antigen. None had strong expression for the panneuroectodermal antigen UJ13/A. There was variable expression of the other markers. The most common IP profile for CP tumors (cytokeratin 18+, PI-153/3+, Thy-1+, UJ 223.8+, and GFAP+ and UJ13A-, UJ 127.11-, and NF-L-) is discussed in the context of the current knowledge of the ontogenetic origin of the CP. It was concluded that chemotherapy for malignant CP tumors can be associated with long-term survival in young children and that the unique IP profile of CP tumors with coexpression of three intermediate filaments suggests new and provocative evidence of their cellular complexity and heterogeneity.

Antibodies, Monoclonal↗
PubMed1992

Dynamic digitized cerebral parenchymography.

Aortic arch injections centred on the head have been performed routinely in patients with cerebral ischaemia. Digital angiograms with modified windowing (low and narrow) have been used. This "cerebral" arch injection allows much improved analysis of the cerebral parenchymal vascularization, giving better understanding of hemispheric ischaemia and making the decision about revascularization more rational.

Angiography, Digital Subtraction↗
PubMed1992

Identification of the ferrioxamine B receptor, FoxB, in Escherichia coli K12.

The photoreactive p-azidobenzoyl analog of ferrioxamine B was used to show that ferrioxamine-B-mediated iron transport is separate and distinct from coprogen-mediated iron transport in Escherichia coli. Photolysis of this analog inhibited uptake of [59Fe]ferrioxamine B but not [59Fe]ferrichrome. Conversely, photolysis of the p-azidobenzoyl analog of coprogen B inhibited uptake of [59Fe]coprogen but not [59Fe]ferrioxamine B or [59Fe]ferrichrome. Photolabeling of outer membranes with p-azidobenzoyl-[59Fe]ferrioxamine B resulted in the labeling of two iron-regulated peptides with molecular masses of about 66 and 26 kDa. Expression of these peptides was increased when ferrioxamine B was the sole iron source. Both peptides were present in outer membrane preparations of the fhuF mutant H1717, but the 66 kDa peptide was not inducible. These results are evidence for an outer membrane receptor in E. coli unique for linear ferrioxamines.

Bacterial Outer Membrane Proteins↗