Search PubMed⌕ Search

Biomedical subjects

K Jones

Publications and source records attributed to K Jones.

At least 217 records · Page 12Linked to original sources
PubMed1996

Health-related behaviour in context: a multilevel modelling approach.

Recent attempts to place individual health-related behaviour in context have been judged largely unsuccessful. This paper examines how this situation might be improved and is especially concerned with the role of quantitative methodologies. It is argued that, whilst recent developments in social theory help provide important theoretical guidelines, they can only be implemented with difficulty in empirical health-related behaviour research if traditional quantitative methodologies are used. It is suggested that the best way to implement social theory within a quantitative framework is to apply the newly developed technique of multilevel modelling. This paper offers an overview of the multilevel approach and outlines its significance for health-related behaviour research. In addition, it details a number of ways in which the multilevel framework can be extended so as to achieve further improvements in the conceptualization of health-related behaviour. To illustrate the value of the technique, the paper finishes by considering one of these extensions in detail and applying it to data recording smoking behaviour in the United Kingdom.

Adolescent↗
PubMed1996

Analyzing perceived limiting long-term illness using U.K. Census Microdata.

The 1991 Census of England, Wales and Scotland is an improvement on previous censuses in providing fine-grained detail on the geography of limiting long-term illness. Another innovation of the 1991 Census is the release of a Sample of Anonymized Records (SARs). These provide a considerable sample of detailed data on individuals at the sub-regional level. This paper explores individual and geographical variations in morbidity through a multilevel analysis of the SARs. Geographical differences in morbidity are found even after allowing for age, sex, ethnicity, housing tenure, social class and car ownership.

Adult↗
PubMed1996

A reciprocal cell-cell interaction mediated by NT-3 and neuregulins controls the early survival and development of sympathetic neuroblasts.

Neurotrophin 3 (NT-3) can support the survival of some embryonic sympathetic neuroblasts before they become nerve growth factor dependent. We show that NT-3 is produced in vivo by nonneuronal cells neighboring embryonic sympathetic ganglia. NT-3 mRNA is produced by these nonneuronal cells in vitro and is up-regulated by platelet-derived growth factor, ciliary neurotrophic factor, and glial growth factor 2 (a neuregulin). Nonneuronal cell-conditioned medium promotes survival and induces TrkA expression in isolated sympathetic neuroblasts, and this activity is blocked by anti-NT-3 antibody. Neuroblasts also enhance NT-3 production by nonneural cells. Neuroblasts synthesize several forms of neuregulin, and antibodies to neuregulin attenuate the effect of the neuroblasts on the nonneuronal cells. These data suggest a reciprocal cell-cell interaction, in which neuroblast-derived neuregulins promote NT-3 production by neighboring nonneuronal cells, which in turn promotes neuroblast survival and further differentiation.

Animals↗
PubMed1996

Management of acute asthma attacks associated with respiratory tract infection: a postal survey of general practitioners in the U.K.

Asthma attacks in general practice are frequently associated with respiratory tract infection. The aim of this study was to examine how U.K. general practitioners (GPs) might use oral steroids and antibiotics in such situations. The timing of follow-up and use of self-management plans were also examined. A postal questionnaire was sent to all 205 GP principals in Bath Health District, U.K. in February and March 1993. Respondents were asked questions regarding the management of an adult and a child presenting with acute asthma associated with respiratory tract infection. Replies were received from 185 of 205 (90%) doctors approached. Antibiotics would have been prescribed by 119 of 179 (66%) doctors for the adult and 98 of 169 (58%) doctors for the child. The modal initial dosage of oral prednisolone was 40 mg for the adult and 30 mg for the child, and modal duration of oral steroid dosage was 5 days for both adult and child. Planned follow-up was mainly doctor initiated within 24 h of initial consultation. There was low reported use of self-management plans (49% for adults and 33% in children over 7 years of age). Antibiotic prescription appears to be common practice by GPs when faced with an acute asthma attack associated with respiratory tract infection. There may also be inadequate duration of oral steroid courses in adults. There is a need to examine further the proper role, if any, of antibiotics in such situations, to determine the optimum dose and course length of oral steroid therapy, and to continue validating the use of self-management plans in acute asthma management.

Acute Disease↗
PubMed1996

Fluency effect of frequency alterations of plus/minus one-half and one-quarter octave shifts in auditory feedback of people who stutter.

The effect of frequency alterations in auditory feedback of people who stutter on stuttering frequency was investigated. Twelve participants who stutter read aloud under nonaltered auditory feedback (NAF) and four conditions of frequency-altered feedback ([FAF], plus/minus one-half and one-quarter octaves) at normal and fast speech rates. Stuttering frequency was significantly higher while reading aloud with NAF relative to the four conditions of FAF (p < 0.05). There were no differences among participants' stuttering frequency between the four FAF conditions (p > 0.05). Reductions in stuttering frequency of approximately 50% to 60% were found with FAF relative to NAF. More disfluencies occurred with the fast versus the normal speech rate condition (p = .0007) irrespective of auditory feedback condition. These findings suggest that slight alterations in the frequency of auditory feedback of people who stutter are fluency-enhancing.

Adult↗
PubMed1996

Phosphorylation of linker histone is associated with transcriptional activation in a normally silent nucleus.

Previous studies have suggested that micronuclear linker histones are phosphorylated by cAMP-dependent protein kinase (PKA) in Tetrahymena (Sweet, M.T., and C.D. Allis. 1993. Chromosoma. 102: 637-647). In this study, we report that a rapid and dramatic phosphorylation of the micronuclear linker histone, delta, occurs early in the sexual pathway, conjugation. Phosphorylated isoforms of delta are detected as early as 30 min after mixing cells of different mating types; blocking pair formation abolishes this induction completely. Phosphorylation of delta is stimulated by the addition of N6-benzoyladenosine 3':5' cyclic monophosphate to starved (nonmating) cells, suggesting that a PKA/cAMP signal transduction pathway is involved. Maximal phosphorylation of delta is observed during meiotic prophase, a period when micronuclei become transcriptionally active. In situ staining, using phospho-delta-specific antibodies combined with [3H]uridine autoradiography, shows that decondensed micronuclear chromatin undergoing active transcription is enriched in phosphorylated delta isoforms. In contrast, condensed inactive micronuclear chromatin is enriched in dephosphorylated delta. These results strongly suggest that phosphorylation of linker histone plays an important and previously unsuspected role in establishing transcriptional competence in micronuclei.

Animals↗
PubMed1996

Fostering science education and science careers at the University of Kentucky.

The Outreach Center for Science and Health Career Opportunities opened at the University of Kentucky Medical Center in July 1993, to provide a central site of coordination for the university's science education activities designed to link those "doing science" at the medical center with students, teachers, and the general population throughout Kentucky. By providing an infrastructure for outreach programs and by being highly visible to the public, the center attracts extramural funding, allows tracking of the program's students, and facilitates the development of science education partnerships between the university of Kentucky communities. The rationale for establishing the center, methods of operation, and impact on the region's science literacy problem are discussed.

Career Choice↗
PubMed1996

Neuroendocrine carcinoma arising in an ovarian mucinous cystadenoma.

A case of neuroendocrine carcinomas arising in the form of a mural nodule in an ovarian mucinous cystadenoma is presented. This represents the third case of neuroendocrine carcinoma arising in an ovarian mucinous tumor. The carcinoma cells were moderately to strongly immunoreactive for enolase, keratin, chromogranin, synaptophysin, and focally, neuron-specific enolase, and contained 130-330 nm neurosecretory granules. The patient presented 9 months after surgery with liver metastases and peritoneal implants. She died of disease within 10 months of initial presentation.

Aged↗
PubMed1996

Quality assessment issues of new immunosuppressive drugs and experimental experience.

There are established quality assessment schemes for the two immunosuppressive drugs that have entered routine clinical use: cyclosporine and tacrolimus. These two drugs, together with sirolimus and mycophenolic acid, have been the subject of recent consensus panel reports that have reached broad agreement on several issues relating to therapeutic monitoring of these agents. While the current quality assessment schemes are not based on validated reference methods, the data they yield on comparative assay performance are of value as a guide to patient management and for clinical studies of drug efficacy.

Cyclosporine↗
PubMed1996

Biofilm formation by the enterobacteriaceae: a comparison between salmonella enteritidis, Escherichia coli and a nitrogen-fixing strain of Klebsiella pneumoniae.

A simple laboratory reactor, which simulates biofilm formation in pipes, was used to compare biofilm formation by three members of the Enterobacteriaceae, namely, an environmental, nitrogen-fixing strain of Klebsiella pneumoniae, a pathogen, Salmonella enteritidis, and a faecal indicator, Escherichia coli. All three attached to CVCP pipe surfaces in the reactor and formed substantial biofilm populations of over a million bacteria cm-2 within 24 h. These populations increased by approximately 10-fold over the next 48 h. Estimates of the numbers of metabolically active cells and the ratios of viable to direct counts showed that Kl. pneumoniae formed the densest and most metabolically active biofilms, followed by Salm. enteritidis and E. coli, respectively. Nitrogen fixation and polysaccharide production (EPS) by Kl. pneumoniae occurred only in mature biofilms and were of no selective advantage in the initiation of biofilms. Despite producing more EPS the rate of attachment of Salm. enteritidis was lower than for Kl. pneumoniae.

Biofilms↗
PubMed1996

The use of selective and differential agars in the isolation of Escherichia coli O157 from dairy herds.

The use of selective and differential agars for the isolation of Escherichia coli O157 from the faeces of dairy herds was investigated. Out of the 614 isolates which were positive for one or more of the selective criteria employed in the media only four proved to be E. coli O157. Ninety-nine per cent of the isolates were false positives. The procedure which resulted in the isolation of E. coli O157 from faecal samples was enrichment in modified Tryptone Soya Broth supplemented with novobiocin and subsequent growth on Chromagar O157.

Agar↗
PubMed1996

Ethanol ingestion and related hypoglycemia in a pediatric and adolescent emergency department population.

OBJECTIVE: To estimate the frequency of associated hypoglycemia in an ethanol-ingesting pediatric and adolescent population. METHODS: The study was a retrospective review of nondiabetic pediatric and adolescent patients with measurable ethanol levels (i.e., > or = 2 mmol/L) who had an ED serum glucose level determined. RESULTS: Over the four-and-a-half-year study period, there were 254,234 pediatric visits. One hundred eleven had ethanol levels determined (0.044% of patients) due to suspected ingestion. Of these 111, 88 had glucose levels determined. The mean age of the 88 patients was 14 years, with a mean glucose level of 5.6 mmol/L [101 mg/dL; interquartile range (IQR) 4.7-6.3 mmol/L] and a mean ethanol level of 30 mmol/L (IQR 15-43 mmol/L). Glucose levels were < 67 mg/dL (hypoglycemia) in three of the 88 (3.4%) ethanol-positive patients; all the hypoglycemic patients had significant behavioral changes. CONCLUSION: In this large retrospective series, the number of patients for whom the clinical suspicion of ethanol ingestion was confirmed was quite small. Hypoglycemia occurred in only 3.4% of these selected patients; all had altered behavior. Pediatric patients with presentations suggesting ethanol intoxication with altered behavior should be assessed for concurrent hypoglycemia.

Adolescent↗
PubMed1996

Molecular technique for rapid identification of mycobacteria.

Identification of mycobacteria through conventional microbiological methods is cumbersome and time-consuming. Recently we have developed a novel bacterial identification method to accurately and rapidly identify different mycobacteria directly from water and clinical isolates. The method utilizes the PCR to amplify a portion of the small subunit rRNA from mycobacteria. The 5' PCR primer has a fluorescent label to allow detection of the amplified product. The PCR product is digested with restriction endonucleases, and an automated DNA sequencer is employed to determine the size of the labeled restriction fragments. Since the PCR product is labeled only at the 5' end, the analysis identifies only the restriction fragment proximal to the 5' end. Each mycobacterial species has a unique 5' restriction fragment length for each specific endonuclease. However, frequently the 5' restriction fragments from different species have similar or identical lengths for a given endonuclease. A set of judiciously chosen restriction enzymes produces a unique set of fragments for each species, providing us with an identification signature. Using this method, we produced a library of 5' restriction fragment sizes corresponding to different clinically important mycobacteria. We have characterized mycobacterial isolates which had been previously identified by biochemical test and/or nucleic acid probes. An analysis of these data demonstrates that this protocol is effective in identifying 13 different mycobacterial species accurately. This protocol has the potential of rapidly (less than 36 h) identifying mycobacterial species directly from clinical specimens. In addition, this protocol is accurate, sensitive, and capable of identifying multiple organisms in a single sample.

Bacteriological Techniques↗
PubMed1996

Urinary leukotriene E4 levels in high-altitude pulmonary edema. A possible role for inflammation.

STUDY OBJECTIVES: Inflammation may contribute to the pathogenesis of high-altitude pulmonary edema (HAPE). This study was designed to determine whether a marker of inflammation, urinary leukotriene E4 (LTE4), is elevated in patients with HAPE. DESIGN: We conducted a case-control study to collect clinical data and urine samples from HAPE patients and healthy control subjects at moderate altitude (> or = 2727 m), and follow-up urine samples from HAPE patients following their return to low altitude (< or = 1,600 m). SETTING: Five medical clinics in Summit County, Colorado. PATIENTS: Questionnaire data were evaluated in 71 HAPE patients and 36 control subjects. Urinary LTE4 levels were determined from a random subset of 38 HAPE patients and 10 control subjects presenting at moderate altitude, and on 5 HAPE patients who had returned to low altitude. MEASUREMENTS AND RESULTS: Using an enzyme immunoassay technique, urinary LTE4 levels were found to be significantly higher in HAPE patients (123 [16 to 468] pg/mg creatinine, geometric mean [range]) than in control subjects (69 [38 to 135]), p = 0.02. Following return to low altitude, urinary LTE4 levels fell significantly from 122 (41.8 to 309) to 53.6 (27.6 to 104) pg/mg creatinine (p = 0.05). Urinary LTE4 levels were not related to age, sex, time at altitude, physical condition or habitual exercise, recent use of alcohol or nonsteroidal anti-inflammatory drugs (NSAIDs), or oxygen saturation. Clinical factors associated with HAPE included male sex, regular exercise, and recent use of NSAIDs. CONCLUSIONS: We conclude that urinary LTE4 levels are elevated in patients with HAPE, supporting the view that HAPE involves inflammatory mechanisms.

Adult↗
PubMed1996

A comparison of reinforcer assessment methods: the utility of verbal and pictorial choice procedures.

We compared three methods of stimulus preference assessment for verbal children and specifically evaluated the utility of a verbal choice procedure for assessing relative reinforcer value. Using a token system, relative preference for five categories of reinforcers, representing 15 different stimuli, was assessed by three methods: a reinforcer survey, a verbal stimulus-choice questionnaire, and a pictorial stimulus-choice procedure. Results showed that the verbal and pictorial stimulus-choice assessments accurately identified high- and low-preference categories for 3 of 4 participants. Survey results alone often rated multiple categories as high preference, were less likely to identify low-preference categories, and were less likely to correspond with the results of a reinforcer assessment.

Attention Deficit Disorder with Hyperactivity↗