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Biomedical subjects

J Harrington

Publications and source records attributed to J Harrington.

At least 19 recordsLinked to original sources
PubMed2000

Reading aloud begins when the computation of phonology is complete.

Naming latency experiments in which monosyllabic items are read aloud are based on the assumption that the vocal response is not initiated until the phonology of the entire syllable has been computed. Recently, this assumption has been challenged by A. H. Kawamoto, C. T. Kello, R. Jones, and K. Bame (1998), who argued instead that the reading-aloud response begins as soon as the initial phoneme is computed. This view would be refuted by evidence of anticipatory coarticulation effects on the initial phoneme due to the nature of the following vowel in the speeded reading-aloud task. The authors provide such evidence.

Humans↗
PubMed1999

Acoustic evidence for dynamic formant trajectories in Australian English vowels.

The extent to which it is necessary to model the dynamic behavior of vowel formants to enable vowel separation has been the subject of debate in recent years. To investigate this issue, a study has been made on the vowels of 132 Australian English speakers (male and female). The degree of vowel separation from the formant values at the target was contrasted to that from modeling the formant contour with discrete cosine transform coefficients. The findings are that, although it is necessary to model the formant contour to separate out the diphthongs, the formant values at the target, plus vowel duration are sufficient to separate out the monophthongs. However, further analysis revealed that there are formant contour differences which benefit the within-class separation of the tense/lax monophthong pairs.

Adult↗
PubMed1998

Management of acquired rectourinary fistulas: outcome according to cause.

PURPOSE: Acquired rectourinary fistulas, an infrequent complication of pelvic conditions, remain a therapeutic problem for which neither a widely accepted classification nor long-term outcome data are available. This study was designed to provide a new etiologic classification system and examine the success of various surgical therapies. It also looked at the need for permanent fecal or urinary diversion or radical excision depending on the cause of the fistula, i.e., benign vs. malignancy-related. METHODS: A retrospective analysis was made of 41 patients treated for acquired rectourinary fistulas between 1980 and 1995. Acquired rectourinary fistulas were classified as 1) benign but caused by Crohn's disease, trauma, perirectal sepsis, or iatrogenic injury; and 2) malignancy-related fistulas secondary to neoplasm, radiation, surgery, or combined tumor and treatment effects. Surgical interventions were classified as repair, excision, fecal diversion, and urinary diversion. RESULTS: Thirty-seven males and 4 females with acquired rectourinary fistula were identified with a mean age of 62 (range, 28-90) years. Nineteen patients had fistulas involving their urethras, and 22 patients had fistulas involving the bladder. Eight patients were not treated surgically; one was not treated because of an advanced malignancy, three because of patient preference, three because of sepsis, and one because of a poor general condition. Of the remaining 33 patients, nine had benign fistulas of which two were the result of Crohn's disease, two were the result of trauma, two were from an iatrogenic response, and three were from perirectal sepsis. Twenty-four patients had malignancy-related fistulas, and five patients had neoplasm at their fistula sites. The remaining 19 patients had malignancy-related fistulas that were the result of cancer treatments. Of the 19 malignancy-related fistulas, 5 were from radiation, 9 were from surgical trauma, and 5 were from radiation and surgical trauma. Forty-nine percent of the patients had undergone attempts at fistula treatment before referral. A resolution of symptoms after initial and reoperative surgery occurred more often in patients with benign fistulas (44 and 100 percent; mean, 1.8 surgeries per patient) compared with malignancy-related fistulas (21 and 88 percent; mean, 2.1 surgeries per patient). The rates of permanent fecal, urinary, and fecal plus urinary diversion were also lower for benign fistulas (11, 0, and 33 percent) compared with malignancy-related fistulas (13, 8, and 54 percent). Permanent diversion was avoided in 56 percent of the benign fistulas but in only 25 percent of the malignancy-related fistulas. The rates of excisional and radical (ileal conduit) surgery were lower for benign fistulas than for malignancy-related fistulas (44 and 11 percent vs. 50 and 54 percent). CONCLUSION: Successful management of rectourinary fistulas typically requires aggressive reoperative therapy with permanent diversion more often required for malignancy-related fistulas. Better outcomes can be anticipated for benign fistulas.

Adult↗
PubMed1998

The Andover Working Group--accelerating the implementation of standards.

The Andover Working Group was formed with the objective to accelerate and broadly deliver standards-based solutions for healthcare which feature plug and play interoperability across the continuum of care. In this paper, organization and processes used by the Andover Working Group are discussed. A description of how multilateral message profiles, combined with object-oriented component middleware supporting application developments, systems integration and systems operation remove many of the barriers to deployment of systems of standards based applications is also given.

Diffusion of Innovation↗
PubMed1997

Significance of individual point mutations, T202C and C314T, in the human Lewis (FUT3) gene for expression of Lewis antigens by the human alpha(1,3/1,4)-fucosyltransferase, Fuc-TIII.

The Lewis alpha(1,3/1,4)-fucosyltransferase, Fuc-TIII, encoded by the FUT3 gene is responsible for the final synthesis of Lea and Leb antigens. Various point mutations have been described explaining the Lewis negative phenotype, Le(a-b-), on erythrocytes and secretions. Two of these, T202C and C314T originally described in a Swedish population, have not been found as single isolated point mutations so far. To define the relative contribution of each of these two mutations to the Lewis negative phenotype, we cloned and made chimeric FUT3 constructs separating the T202C mutation responsible for the amino acid change Trp68 --> Arg, from the C314T mutation leading to the Thr105 --> Met shift. COS-7 cells were transfected and the expression of Fuc-TIII enzyme activity and the presence of Lewis antigens were determined. There was no decrease in enzyme activity nor of immunofluorescence staining on cells transfected with the construct containing the isolated C314T mutation compared with cells transfected with a wild type FUT3 allele control. No enzyme activity nor immunoreactivity for Lewis antigens was detected in FUT3 constructs containing both mutations in combination. The T202C mutation alone decreased the enzyme activity to less than 1% of the activity of the wild type FUT3 allele. These results demonstrate, that the Trp68 --> Arg substitution in human Fuc-TIII is the capital amino acid change responsible for the appearance of the Le(a-b-) phenotype on human erythrocytes in individuals homozygous for both the T202C and C314T mutations.

Alleles↗
PubMed1997

Individual risk factors for early repetition of deliberate self-harm.

This study investigated individual factors associated with repetition of deliberate self-harm (DSH) within three months of a first-ever episode. Individuals from an 'at risk' population who repeated DSH (N = 25) were compared with a socio-demographically matched group of 'at risk' individuals who did not engage in a further episode of DSH (N = 18). In comparison with the 'single DSH' individuals, those in the 'repeated DSH' group demonstrated significantly higher levels of depression and hopelessness, were significantly less skilled at problem solving, were significantly less likely to report the availability of a confidante and significantly more likely to identify that the reason for their DSH was to communicate their desperation. The implications of these findings for risk assessment and interventions are noted.

Adaptation, Psychological↗
PubMed1995

Lagging strand DNA synthesis at the eukaryotic replication fork involves binding and stimulation of FEN-1 by proliferating cell nuclear antigen.

The 5'-->3'-exonuclease domain of Escherichia coli DNA polymerase I is required for the completion of lagging strand DNA synthesis, and yet this domain is not present in any of the eukaryotic DNA polymerases. Recently, the gene encoding the functional and evolutionary equivalent of this 5'-->3'-exonuclease domain has been identified. It is called FEN-1 in mouse and human cells and RTH1 in Saccharomyces cerevisiae. This 42-kDa enzyme is required for Okazaki fragment processing. Here we report that FEN-1 physically interacts with proliferating cell nuclear antigen (PCNA), the processivity factor for DNA polymerases delta and epsilon. Through protein-protein interactions, PCNA focuses FEN-1 on branched DNA substrates (flap structures) and on nicked DNA substrates, thereby stimulating its activity 10-50-fold but only if PCNA can functionally assemble as a toroidal trimer around the DNA. This interaction is important in the physical orchestration of lagging strand synthesis and may have implications for how PCNA stimulates other members of the FEN-1 nuclease family in a broad range of DNA metabolic transactions.

Base Sequence↗
PubMed1995

Healthcare Information Framework.

CEN committee TC 251 Medical Informatics, has set up a project team charged with producing a European pre-standard ENV on Healthcare Information Framework (HIF). The HIF is based on abstraction from a specific information system architecture to a reference architecture and further to a conceptual architectural framework based on serving open, distributed and heterogeneous healthcare enterprises. To specify the suitable healthcare information system architecture modelling of the healthcare enterprise is required. As there is no one method serving all needs, the HIF gives guidance on what aspects to look at in selecting a suitable modelling method. It is expected that the work will be completed by early 1995.

Artificial Intelligence↗
PubMed1995

In vitro growth of neonatal rat islet cells is stimulated by adhesion to matrix.

We examined DNA synthesis in non-enzymatically isolated neonatal rat pancreatic islets sub-cultured to eliminate fibroblast contamination, which was excluded both by demonstrating no effect of fibroblast growth factor (FGF) on 3H-thymidine incorporation and by immunofluorescence of attached islets using a mouse anti-fibroblast monoclonal antibody. 3H-thymidine incorporation in islets increased with increasing glucose up to a concentration of 21.1 mM in both free-floating islets (11,789 cpm/micrograms DNA +/- 1,610 SEM) and islets attached to fibronectin coated plastic (43,043 cpm/micrograms DNA +/- 9,203 SEM). These values were significantly higher when compared to 3H-thymidine incorporation in medium containing 11.1 mM glucose (p < 0.007, and p < 0.0001 for free-floating and attached islets respectively). 3H-thymidine incorporation was significantly higher in attached islets than in free-floating islets at all glucose concentrations tested (p < 0.005 at 11.1 mM, 16.1 mM, and 21.1 mM; and p < 0.01 at 26.1 mM). 5-bromo-2'-deoxyuridine (BrDU) staining of islets showed an increased number of positive nuclei in cells localised within attached islets (37.6 nuclei per islet +/- 5.1 SEM) compared to free-floating islets (7.62 nuclei per islet +/- 1.04 SEM, p < 0.001), indicating that attachment influenced proliferation of islet cells not physically in contact with the matrix. No difference in glucose-stimulated insulin release was observed between attached and free-floating islets. In conclusion, a fibroblast free islet culture was used to document the stimulatory effect of islet attachment on DNA synthesis, which was greater than the stimulation exerted by glucose alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Insulin secretion and DNA synthesis of cultured islets of Langerhans are influenced by the matrix.

To compare the effect of matrix on glucose-stimulated insulin release, we cultured neonatal (3- to 5-day-old) rat islets of Langerhans, devoid of mesenchymal cell, on fibronectin, Cell-Tak, or endothelial basement membranes, free-floating, or dispersed into single cells. We also examined the rate of DNA synthesis during the culture period. Compared to free-floating islets [0.386 +/- 0.03 (SEM) ng per 24 h/ng total], single-cell cultures had the lowest basal insulin release (0.159 +/- 0.03 ng per 24 h/ng total; p < 0.0001), which was also low in islets attached to endothelial basement membrane (0.294 +/- 0.02 ng per 24 h/ng total; p = 0.01). The spontaneous insulin release (1 h in medium with 2.7 mM glucose) was lowest in islets attached to endothelial basement membrane (0.003 +/- 0.00023 ng per h/ng total; p < 0.0001 vs. free-floating) and highest in single-cell cultures (0.01153 +/- 0.00259 ng per h/ng total; p = 0.039 vs. free-floating). The ability to increase insulin release following a glucose challenge (16.1 mM for 1 h) was highest in islets grown on endothelial basement membranes (16.4-fold) and fibronectin (12.6-fold) compared to free-floating islets (8.7-fold), Cell-Tak (7.9-fold), and single-cell cultures (5.4-fold).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Asthma severity and morbidity in a population sample of Sydney school children: Part I--Prevalence and effect of air pollutants in coastal regions.

BACKGROUND: In two regions of Sydney where sewage treatment facilities with high temperature sludge burning incinerators are installed, there was concern that the resultant emissions were causing a local increase in symptoms of asthma and other allergic diseases. AIM: To investigate whether living in a region with high temperature sludge burning incinerators was associated with an increased prevalence of childhood asthma or allergy. METHODS: We studied 713 children aged eight-12 years in two regions close to incinerators and 626 children in a control region with no sludge burning incinerator. We measured respiratory illness in the previous year by questionnaire, airway hyper-responsiveness (AHR) by histamine inhalation test, and atopy by skin prick tests. 'Current asthma' was defined as AHR and recent wheeze. RESULTS: Recordings of oxides of nitrogen and sulphur, hydrogen sulphide, ozone and particulates during the study period showed that the level of pollutants did not vary in any major way between the study regions and the control region. The prevalence of current asthma, atopy, symptom frequency or any category of severity of asthma illness was not significantly different between the control and study regions. CONCLUSIONS: This suggests that factors other than intermittent or industrial air pollutants are responsible for the high prevalence of asthma symptoms, asthma medication use, asthma morbidity and AHR in the study of children.

Air Pollutants↗
PubMed1994

The contribution of the murmur and vowel to the place of articulation distinction in nasal consonants.

Recent studies have shown that the acoustic relationship between the murmur and the vowel at the nasal-vowel boundary is highly informative for the [m]-[n] distinction. In the present paper, the contribution of relational information is reassessed by classifying 1946 syllable-initial and 2848 syllable-final nasal consonants taken from continuous speech data. Relational information in the acoustic waveform is based on difference spectra, in which spectral information in the vowel is subtracted from spectral information in the murmur, and on combined spectra in which classifications are made from combinations of murmur and vowel spectra. These two kinds of relational spectra are compared with static spectra, in which single spectral slices are taken in either the murmur or the vowel. Contrary to recent theoretical predictions, difference spectra are shown to perform more poorly than some kinds of static spectra. However, since classification scores from combined spectra are better than from either static or difference spectra, cues to nasal place of articulation can nevertheless be defined as relational. In the best scoring combined spectra, classification scores on open tests are just under 94% correct for syllable-initial nasals and just under 82% correct for syllable-final nasals. The high classification scores show that there is considerable information in the acoustic waveform for identifying nasal place of articulation from continuous speech data.

Female↗
PubMed1993

Recommendations for an object oriented healthcare information model.

The need for a healthcare information model as a component in a framework of standards for healthcare data interchange is identified. Key requirements for a method to support development of a healthcare information model are defined and recommendations for development of an Object Oriented Healthcare Information Model are presented.

Computer Communication Networks↗
PubMed1992

Analysis of the defect in DNA end joining in the murine scid mutation.

Murine severe combined immune deficiency (scid) is marked by a 5,000-fold reduction in coding joint formation in V(D)J recombination of antigen receptors. Others have demonstrated a sensitivity to double-strand breaks generated by ionizing radiation and bleomycin. We were interested in establishing the extent of the defect in intramolecular and intermolecular DNA end joining in lymphoid and nonlymphoid cells from scid mice. We conducted a series of studies probing the ability of these cells to resolve free ends of linear DNA molecules having various biochemical end configurations. We find that the stable integration of linear DNA into scid fibroblasts is reduced 11- to 75-fold compared with that in normal fibroblasts. In contrast, intramolecular and intermolecular end joining occur at normal frequencies in scid lymphocytes and fibroblasts. This normal level of end joining is observed regardless of the type of overhang and regardless of the requirement for nucleolytic activities prior to ligation. The fact that free ends having a wide variety of end configurations are recircularized normally in scid cells rules out certain models for the defect in scid. We discuss the types of DNA end joining reactions that are and are not affected in this double-strand break repair defect in the context of a hairpin model for V(D)J recombination.

Animals↗