Search PubMed⌕ Search

Biomedical subjects

C Dunn

Publications and source records attributed to C Dunn.

At least 19 recordsLinked to original sources
PubMed2003

Serum IgA and IgG functional antibodies and their subclasses to Streptococcus pneumoniae capsular antigen found in two aged-matched cohorts of children with and without otitis media with effusion.

The relationship between acute otitis media and otitis media with effusion (OME) is uncertain and the aetiology of OME is multifactorial. Otitis media with effusion may be an inflammatory condition; both bacteria and viral infections could play a part in this inflammation. The four bacteria Streptococcus pneumoniae, Haemophilus influenza, Staphylococcus aureus and Branhamella catarrhalis cause 60% of the infections whereas S. pneumoniae accounts for up to 35%. IgA provides the dominant surface response to polysaccharide and lipopolysaccharide antigens, of which IgA2 is the main subclass. Once the mucosa has been breached, most protection is provided by IgG. IgG2 acts mainly against bacterial capsular antigens. This study looked at two groups of 50 children with and without OME who were aged between 3 and 10 years. The aims were to determine if, firstly, the levels of the serum immunoglobulins were different in the two groups, secondly whether these children made the appropriate antibody response to the capsular antigen to S. pneumoniae (PCP), and finally if there was a delay in the maturity of the IgA response. The total IgG, IgA and all subclass levels were measured using radial immunodiffusion. Levels of functional IgA and IgG were measured using ELISAs (25 patients in each group). The results were analysed with non-parametric tests. The immunoglobulin levels were within the normal levels for both groups. There were very good correlations between the IgG total anti-PCP and the IgG2 anti-PCP (R > 0.9, p = 0.001). There was a good correlation between the levels of both IgG total and IgG2 anti-PCP against IgA total anti-PCP in both groups (R > 0.85, p > 0.01). This confirms a normal antibody response between both groups of patients. The ages of the controls and patients (50 samples) were correlated with increasing titres of circulating functional antibodies (P = 0.001). This is highly suggestive of a normal age-related response. In conclusion, the findings were contradictory to our original hypothesis that there is a subtle difference in surface protection between children with and without OME. We believe that a previous history of recurrent acute otitis media is unrelated to the development of OME after 3 years of age.

Chi-Square Distribution↗
PubMed2003

Surgical emphysema following nose blowing.

A 20-year-old woman developed gross surgical emphysema tracking down to the chest after an episode of nose blowing. Fortunately there were no ocular complications and the patient settled with conservative management. Follow-up showed no recurrence. The case presented illustrates the very rare complication of orbital fracture following nose blowing.

Adult↗
PubMed2001

'Even the birds round here cough': stigma, air pollution and health in Teesside.

In this paper we explore how the presence of hazardous industry may affect the identity of a place and the people who live there. Drawing on Goffman's seminal work on stigma - together with recent debates on environmental and technological stigma - we extend the concepts of difference and spoiled identity from the individual to place. The paper is based on a qualitative study which explored public perceptions of the risks to health from air pollution in Teesside, a heavily industrialised area in north-east England. We did not set out to study stigma per se in this study, but emergent themes produced by grounded theory analysis highlighted the way in which the presence of technologies, air pollution, poor health and social exclusion may be used as 'discrediting' characteristics, to stigmatise one place, whilst confirming the usualness of another. We demonstrate place stigma as a complex, multiple and re-inforcing concept.

Adolescent↗
PubMed2001

The use of brief interventions adapted from motivational interviewing across behavioral domains: a systematic review.

AIMS: To examine the effectiveness of brief behavioral interventions adapting the principles and techniques of Motivational Interviewing (MI) to four behavioral domains: substance abuse, smoking, HIV risk and diet/exercise. DESIGN: We conducted a systematic review of 29 randomized trials of MI interventions. Data on methodological quality were extracted and tabulated. Between-group behavior change effect sizes and confidence intervals were calculated for each study. FINDINGS: Due to varying intervention time lengths, targeted problem behaviors, settings and interventionists' backgrounds and skill levels, outcomes were not combined meta-analytically. Sixty per cent of the 29 studies yielded at least one significant behavior change effect size. No significant association between length of follow-up time and magnitude of effect sizes was found across studies. There was substantial evidence that MI is an effective substance abuse intervention method when used by clinicians who are non-specialists in substance abuse treatment, particularly when enhancing entry to and engagement in more intensive substance abuse treatment treatment-as-usual. Data were inadequate to judge the effect of MI in the other domains. Client attribute-treatment interactions were understudied and the sparse and inconsistent findings revealed little about the mechanism by which MI works or for whom it works best. CONCLUSION: To determine more effectively how well MI works in domains other than substance abuse and for whom it works best in all domains, researchers should study MI with risk behaviors other than substance abuse, while examining both interactions and the theoretical components of MI.

Adolescent↗
PubMed2001

Acceptance of neonatal genetic screening for hereditary hemochromatosis by informed parents.

The aim of this study was to assess attitudes to neonatal genetic screening for hereditary hemochromatosis. A total of 135 consecutive, pregnant women and their partners attending a hospital antenatal clinic in the Australian Capital Territory were given detailed written and verbal information about potential risks and benefits of neonatal genetic screening. Issues such as uncertainty of disease expression, confidentiality, genetic discrimination, and storage of genetic data were addressed. Attitudes were assessed by interview and questionnaire. There was a high level of acceptance for neonatal genetic screening in general (99%) and for hemochromatosis in particular (91.5%). There was no association of prior knowledge of hemochromatosis, family history of hemochromatosis, ethnicity, age, education, or occupation class with nonacceptance. Of the subjects, 39.5% reported feeling "a little anxious" about the prospect of screening their infants, although only 5.4% reported feeling "very anxious." Reasons given for nonacceptance of screening included inability of the child to give informed consent, insufficient evidence that diagnosis of hemochromatosis in childhood is beneficial, risk of discrimination on genetic grounds, lack of agreement between partners, and privacy issues. These data suggest that an Australian neonatal genetic screening program for hemochromatosis is likely to be accepted by this and similar groups of subjects, but there should be an opportunity for parents who object to screening to opt out of any such program.

Adolescent↗
PubMed2001

Families with deaf members: American Annals of the Deaf, 1996 to 2000.

The authors provide an overview of 21 articles from several countries focusing on families with deaf members published in the literary issues of the American Annals of the Deaf from 1996 to 2000. Four categories were identified: Interaction and Involvement, Support Services, Stress and Coping, and Decision Making. The articles represent a commendable expansion of focus from the mother-child dyad to increased attention to fathers, siblings, extended family members, and significant nonfamily members such as deaf adults. The heterogeneity of families was a striking factor, even within those studies dealing with relatively homogeneous populations. Services appeared to be most effective within middle-class, educated family units, illustrating the need for more comprehensive services sensitive to the needs of families from less affluent backgrounds and with lower levels of education. In general, services to families with deaf children may be characterized as better than in the past but still in need of significant sensitivity and improvement. The presence of a deaf child in a family with hearing parents may cause stress, but parents have the flexibility to respond in a positive and beneficial way, especially when provided adequate information and support. The idea that hearing parents go through a grieving process involving the identification of deafness in their child seems to be an overstatement.

Adaptation, Psychological↗
PubMed1999

Fine mapping of the binding sites of monoclonal antibodies raised against the Pk tag.

The monoclonal antibody (mAb) SV5-Pk is used widely in a variety of procedures to detect recombinant proteins tagged with the Pk tag, a 14 amino acid sequence derived from the P and V proteins of the paramyxovirus Simian Virus 5. Here we report on the isolation and characterisation of four additional SV5-Pk mAbs (termed SV5-Pk2 to 5) that bind the Pk tag. All the SV5-Pk mAbs can detect Pk tagged recombinant proteins in a variety of immunological procedures, including ELISA and immunofluorescence. Using SPOT technology, the minimal binding epitope of each SV5-Pk mAb was defined by one-sided terminal truncation analysis from either the amino- or carboxy-ends of the Pk peptide. Each mAb recognises slightly different epitopes within the Pk tag, ranging from 5 to 9 amino acids in length. The equilibrium dissociation constants (Kd) of the mAbs, as measured by surface plasmon resonance, ranged from approximately 20 to 60 pmol. Cysteine scanner mutations throughout the Pk tag revealed that some amino acids within the minimal binding epitopes were critical for mAb binding, while others could readily be substituted with little or no effect on antibody binding. The development of the Pk tag as a spacer arm for site-directed chemical coupling, and the use of the mAbs to monitor purification and coupling procedures, is discussed.

Amino Acid Sequence↗
PubMed1999

Creation of a stable human reporter cell line suitable for FACS-based, transdominant genetic selection.

Quality bioassays are central to all approaches directed at understanding or perturbing the function of proteins. One type of cell-based bioassay involves an engineered reporter whose transcriptional activity serves as a readout for upstream signals of a biochemical pathway(s) that feeds into the reporter. We describe a general strategy for creating a mammalian reporter line with attributes suitable for a high complexity, en masse transdominant genetic screen. The basic criteria required of the mammalian cells engineered with the reporter include ease of maintenance, ease of sorting by FACS, ability to be transduced by retroviruses, and high expression of transduced peptides or cDNAs. For maximal enrichment during selection, the reporter line should have a relatively homogeneous response and a high signal-to-background ratio. We use a melanoma cell line transduced with a retinoic-acid-responsive promoter coupled to a GFP reporter as a case study to demonstrate the strategy. We characterize an optimized retinoic-acid-responsive reporter clone to determine the kinetics of reporter induction and decay in the presence and absence of retinoids. Dose-response studies reveal that the reporter responds to all-trans retinoic acid with an EC50 of approximately 1 nM. The strategy described is general and may be applied to create other reporter lines that respond to a specific stimulus.

Base Sequence↗
PubMed1999

Dietary glycine prevents the development of liver tumors caused by the peroxisome proliferator WY-14,643.

Previous studies demonstrated that dietary glycine prevents elevated rates of cell proliferation following treatment with the peroxisome proliferator and liver carcinogen WY-14,643. Since increased cell replication is associated with the development of hepatic cancer caused by peroxisome proliferators, glycine may have anti-cancer properties. Therefore, experiments were designed to test the hypothesis that dietary glycine would inhibit the hepatocarcinogenic effect of WY-14,643. Male F344 rats were fed four different NIH 07-based diets: 5% glycine; 5% valine for nitrogen balance (control); 0.1% WY-14,643 + 5% valine (WY-14,643); 0.1% WY-14,643 + 5% glycine (WY-14,643 + glycine). Food consumption did not differ among the groups, but WY-14,643-fed rats weighed 10-25% less than expected based on previous studies. Serum glycine levels were elevated 4-5-fold by glycine-containing diets; however, the 10-fold increase in peroxisomal enzyme activity caused by WY-14,643 was unaffected by the addition of 5% glycine to the diet. After 22 weeks, livers from rats fed WY-14,643 had a similar incidence and multiplicity of proliferative lesions (foci and adenomas) to those fed WY-14,643 + glycine. Moreover, cell proliferation in the surrounding 'normal' parenchyma (labeling index approximately 4%) and foci (labeling index approximately 50%) did not differ between WY-14,643 and WY-14,643 + glycine-fed rats. However, after 51 weeks of dietary exposure to WY-14,643, glycine prevented formation of small (0-5 mm diameter) tumors by 23% and inhibited the development of medium size (5-10 mm) tumors by 64%. Furthermore, glycine prevented the formation of the largest tumors (>10 mm) by nearly 80%. Thus, glycine did not inhibit early foci formation; however, it significantly decreased their ability to progress to tumors. Moreover, the inhibitory effect of glycine was greater with increasing tumor size. These studies demonstrate that dietary glycine prevents the development of hepatic tumors caused by the peroxisome proliferator WY-14,643 consistent with the idea that it may be an effective chemopreventive agent.

Animals↗
PubMed1998

Aerosolized albuterol improves airway reactivity in infants with acute respiratory failure from respiratory syncytial virus.

The objective of this investigation was to measure the bronchodilator effect of aerosolized albuterol on infants with respiratory syncytial virus (RSV)-induced respiratory failure. Infants who required intubation and mechanical ventilator support for RSV disease were eligible for this prospective, nonrandomized study. Pulmonary function tests, including respiratory mechanics by least mean square analysis, small airway function by rapid thoraco-abdominal compression, and functional residual capacity by nitrogen washout were performed before and 20 min after inhalation of 20-40 breaths of undiluted (0.5%) albuterol solution via a small-volume nebulizer. Analysis of maximum expiratory flow at functional residual capacity (V'maxFRC) before and after albuterol administration was performed using a t-test for paired comparisons. A two-tailed P-value of less than 0.05 was considered statistically significant. Twenty-five infants (mean +/-SD postconceptional age = 45 +/- 5 weeks) were enrolled. Thirteen of the 25 infants had a prior history of prematurity and/or cardiorespiratory disease. After aerosolized albuterol, mean V'maxFRC increased significantly from 48 +/- 46 ml/sec to 65 +/- 59 ml/sec (P = 0.03); however, only three patients had an increase into the normal range. Three patients had a substantial (40-50%) decrease in V'maxFRC. These findings suggest that during the acute phase of severe RSV respiratory infection some of this group of very young infants had airway reactivity that improved in response to inhaled albuterol.

Acute Disease↗
PubMed1998

Lung cancer, proximity to industry, and poverty in northeast England.

This study assesses whether deprived populations living close to industry experience greater mortality from lung cancer than populations with comparable socioeconomic characteristics living farther away. Mortality data, census data, a postal survey of living circumstances, historic and contemporary data on air quality and a historic land-use survey were used. Analysis was based on two conurbations in England, Teesside and Sunderland. Housing estates in Teesside were selected based on socioeconomic criteria and distinguished by proximity to steel and chemical industries; they were grouped into three zones: near (A), intermediate (B), and farther (C), with a single zone in Sunderland. We included 14,962 deaths in 27 estates. Standardized mortality ratios (SMR) for lung cancer [International Classification of Diseases #9 (ICD-9) 162] and cancers other than lung (ICD-9 140-239, excluding 162), and sex ratios were calculated. Mortality from lung cancer was well above national levels in all zones. For men, a weak gradient corresponding with proximity to industry at younger ages reversed at older ages. In women 0-64 years of age, stronger gradients in lung cancer mortality corresponded with proximity to industry across zones A, B, and C (SMR = 393, 251, 242, respectively). Overall rates in Teesside were higher than Sunderland rates for women aged 0-64 years (SMR = 287 vs. 185) and 65-74 years (SMR = 190 vs. 157). The association between raised lung cancer mortality and proximity to industry in women under 75 years of age could not be explained by smoking, occupation, socioeconomic factors, or artifact. Explanations for differences between men and women may include gender-specific occupational experiences and smoking patterns. Our judgment is that the observed gradient in women points to a role for industrial air pollution.

Adolescent↗
PubMed1998

Nutrition and the client with AIDS.

The nutritional problems that go along with HIV infection and AIDS are significant and in fact contribute to death. Nutrition not only affects overall health but one's ability to respond to therapies and quality of life. Malnutrition and "wasting syndrome" result from compromised nutritional status. Early detection and intervention can decrease the dramatic problems caused by these conditions. Regardless of the stage of illness, Medical Nutrition Therapy needs to be individualized and prioritized as an integral part of one's total care.

HIV Enteropathy↗
PubMed1997

A comparison of the effectiveness of malignancy detection in body fluid examination by the cytopathology and hematology laboratories.

BACKGROUND: Body fluid specimens in many institutions are submitted for cytologic examination as well as for examination in a clinical microscopy or hematology laboratory. The cytology laboratory is generally seen as the standard for detection of malignancy, whereas the clinical microscopy laboratory is often depended on predominantly for cell counting and categorization. METHODS: To analyze the effectiveness of the hematology laboratory at detecting malignant fluids, this study retrospectively analyzed reports on 397 body fluid specimens (cerebrospinal, pericardial, peritoneal, and pleural) that were concurrently submitted over a 12-month period to both the cytopathology laboratory and the hematology laboratory. RESULTS: Thirty-seven (9.3%) of the cases were diagnosed as malignant by at least one of the two examinations. The cytopathology examination reported 27 (73%) of the 37 malignant cases as malignant and 30 (81.1%) as at least atypical (27 malignant and 3 inconclusive), and the hematology examination reported 34 (91.9%) as malignant and 36 (97.3%) as at least atypical. A concordant malignant diagnosis was given by both laboratories in 24 (64.9%) of the 37 cases. CONCLUSIONS: These results show that examination of specimens by the hematology laboratory can provide a highly sensitive diagnostic evaluation in addition to its more customary role of providing timely cell counts.

Ascitic Fluid↗
PubMed1996

Infection and allergy incidence in ambulatory surgery patients using white petrolatum vs bacitracin ointment. A randomized controlled trial.

OBJECTIVE: To assess the effect of white petrolatum vs bacitracin ointment on wound infection incidence, allergic contact dermatitis incidence, and healing characteristics. DESIGN: Randomized, double-blind, prospective trial comparing white petrolatum with bacitracin ointment in postprocedure wound care. SETTING: A general outpatient dermatology clinic and a tertiary referral advanced surgical procedure clinic at Walter Reed Army Medical Center, Washington, DC. PATIENTS: A total of 922 patients who had dermatologic surgery with a total of 1249 wounds. MAIN OUTCOME MEASURES: The incidence of infection and allergic contact dermatitis during a follow-up period of 4 weeks. Healing characteristics were secondary outcomes. RESULTS: Of the 922 patients enrolled, 440 in the white petrolatum group and 444 in the bacitracin group were evaluable for clinical response. The 2 treatment groups had comparable baseline characteristics. Thirteen patients developed postprocedure infection (1.5%), 9 (2.0%) in the white petrolatum group vs 4 (0.9%) in the bacitracin group (95% confidence interval for difference, -0.4% to 2.7%; P=.37). Eight infections (1.8%) in the white petrolatum group were due to Staphylococcus aureus vs none in the bacitracin group (P=.004). No patient in the group using white petrolatum developed allergic contact dermatitis vs 4 patients (0.9%) in the group using bacitracin (P=.12). Additionally, there were no clinically significant differences in healing between the treatment groups on day 1 (P=.98), day 7 (P=.86), or day 28 (P=.28) after the procedure. CONCLUSIONS: White petrolatum is a safe, effective wound care ointment for ambulatory surgery. In comparison with bacitracin, white petrolatum possesses an equally low infection rate and minimal risk for induction of allergy.

Adult↗
PubMed1996

Isolation and characterization of conformation sensitive antierythropoietin monoclonal antibodies: effect of disulfide bonds and carbohydrate on recombinant human erythropoietin structure.

We have isolated and characterized three anti-recombinant human erythropoietin (rHuEPO) monoclonal antibodies (MoAbs) that recognize nonoverlapping epitopes on rHuEPO. Anti-EPO MoAb D11 neutralizes rHuEPO activity whereas MoAbs F12 and 9G8A do not. This suggests that D11 may bind to the rHuEPO active site. MoAbs F12 and D11 recognize conformation dependent epitopes whereas 9G8A does not. Immunoassays were developed for each monoclonal. The 9G8A immunoassay was novel and useful because immunoreactivity increased when rHuEPO was denatured. Disruption of disulfide bonds or removal of carbohydrate increased 9G8A immunoreactivity, which suggests that these elements are important for rHuEPO structure or stability.

Antibodies, Monoclonal↗
PubMed1996

A controlled trial of remacemide hydrochloride in Huntington's disease.

We conducted a randomized, double-blind, placebo-controlled tolerability study of a N-methyl-D-aspartate (NMDA) glutamate receptor ion-channel blocker, remacemide hydrochloride, in 31 independently ambulatory patients (18 men, 13 women) with Huntington's disease (HD). Subjects were randomized to receive either placebo or active remacemide at dosages of 200 mg/day or 600 mg/day. The primary outcome measure was the proportion of subjects able to complete the study with the assigned treatment. Remacemide was generally well tolerated, and no significant differences between the treatment arms were found in the primary outcome measure. A trend toward improvement in chorea was observed among subjects administered remacemide 200 mg/day. Based on the tolerability and safety demonstrated during this short-term trial, remacemide warrants more extended controlled investigation in patients with HD.

Acetamides↗