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Biomedical subjects

M Silverman

Publications and source records attributed to M Silverman.

At least 19 recordsLinked to original sources
PubMed2007

Asthma in young south Asian women living in the United Kingdom: the importance of early life.

BACKGROUND: Studies of immigrants suggest that the environment during fetal life and duration of residence in the host country might influence the development of asthma. Little is known about the importance of the timing of the exposure in the host country and whether migrants might be especially vulnerable in certain age windows. OBJECTIVE: We compared the reported prevalence of asthma between young white and south Asian women in the United Kingdom, and investigated associations with country of birth and age at immigration. METHODS: A questionnaire on atopic disorders was posted to 2380 south Asian and 5796 white young mothers randomly sampled in Leicestershire. Data on ethnicity were also available from maternity records. Data were analysed using multivariable logistic regression and a propensity score approach. Results The reported prevalence of asthma was 10.9% in south Asian and 21.8% in white women. South Asian women who migrated to the United Kingdom aged 5 years or older reported less asthma (6.5%) than those born in the United Kingdom or who migrated before age 5 (16.0%), with an adjusted odds ratio of 0.38 [95% Confidence Interval 0.23-0.64, P<0.001]. For those who migrated aged over 5 years, the prevalence did not alter with the duration of residence in the United Kingdom. Current exposure to common environmental risk factors had relatively little effect on prevalence estimates. CONCLUSION: These data from a large population-based study support the hypothesis that early life environmental factors influence the risk of adult asthma.

Adult↗
PubMed2006

Parental understanding of wheeze and its impact on asthma prevalence estimates.

The epidemiology of wheeze in children, when assessed by questionnaires, is dependent on parents' understanding of the term "wheeze". In a questionnaire survey of a random population sample of 4,236 children aged 6-10 yrs, parents' definition of wheeze was assessed. Predictors of a correct definition were determined and the potential impact of incorrect answers on prevalence estimates from the survey was assessed. Current wheeze was reported by 13.2% of children. Overall, 83.5% of parents correctly identified "whistling or squeaking" as the definition of wheeze; the proportion was higher for parents reporting wheezy children (90.4%). Frequent attacks of reported wheeze (adjusted odds ratio (OR) 3.0), maternal history of asthma (OR 1.5) and maternal education (OR 1.5) were significantly associated with a correct answer, while the converse was found for South Asian ethnicity (OR 0.6), first language not English (OR 0.6) and living in a deprived neighbourhood (OR 0.6). In summary, the present study showed that misunderstanding could lead to an important bias in assessing the prevalence of wheeze, resulting in an underestimation in children from South Asian and deprived family backgrounds. Prevalence estimates for the most severe categories of wheeze might be less affected by this bias and questionnaire surveys on wheeze should incorporate measures of parents' understanding of the term wheeze.

Asthma↗
PubMed2006

Locally generated particulate pollution and respiratory symptoms in young children.

BACKGROUND: Particulate matter <10 mum (PM(10)) from fossil fuel combustion is associated with an increased prevalence of respiratory symptoms in children and adolescents. However, the effect of PM(10) on respiratory symptoms in young children is unclear. METHODS: The association between primary PM(10) (particles directly emitted from local sources) and the prevalence and incidence of respiratory symptoms was studied in a random sample cohort of 4400 Leicestershire children aged 1-5 years surveyed in 1998 and again in 2001. Annual exposure to primary PM(10) was calculated for the home address using the Airviro dispersion model and adjusted odds ratios (ORS) and 95% confidence intervals were calculated for each microg/m(3) increase. RESULTS: Exposure to primary PM(10) was associated with the prevalence of cough without a cold in both 1998 and 2001, with adjusted ORs of 1.21 (1.07 to 1.38) and 1.56 (1.32 to 1.84) respectively. For night time cough the ORs were 1.06 (0.94 to 1.19) and 1.25 (1.06 to 1.47), and for current wheeze 0.99 (0.88 to 1.12) and 1.28 (1.04 to 1.58), respectively. There was also an association between primary PM(10) and new onset symptoms. The ORs for incident symptoms were 1.62 (1.31 to 2.00) for cough without a cold and 1.42 (1.02 to 1.97) for wheeze. CONCLUSION: In young children there was a consistent association between locally generated primary PM(10) and the prevalence and incidence of cough without a cold and the incidence of wheeze which was independent of potential confounders.

Air Pollution↗
PubMed2006

The therapy of pre-school wheeze: appropriate and fair?

The current study aimed to assess prevalence and distribution of use of asthma medication for wheeze in pre-school children in the community. We sent a postal questionnaire to the parents of a random population-based sample of 4,277 UK children aged 1-5 years; 3,410 participated (children of south Asian decent were deliberately over-represented). During the previous 12 months, 18% of the children were reported to have received bronchodilators, 8% inhaled corticosteroids (ICS) and 3% oral corticosteroids. Among current wheezers these proportions were 55%, 25%, and 12%, respectively. Use of ICS increased with reported severity of wheeze, but did not reach 60% even in the most severe category. In contrast, 42% of children receiving ICS reported no or very infrequent recent wheeze. Among children with the episodic viral wheeze phenotype, 17% received ICS compared with 40% among multiple-trigger wheezers. Use of ICS by current wheezers was less common in children of South Asian ethnicity and in girls. Although a high proportion of pre-school children in the community used asthma inhalers, treatment seemed to be insufficiently adjusted to severity or phenotype of wheeze, with relative under-treatment of severe wheeze with ICS, especially in girls and South Asian children, but apparent over-treatment of mild and episodic viral wheeze and chronic cough.

Asthma↗
PubMed2006

Transmission of Mycobacterium tuberculosis from an infant.

SETTING: This report investigates the unusual transmission of Mycobacterium tuberculosis from a 12-week-old infant with nosocomially acquired tuberculosis (TB). Compliance with recommendations on the post-exposure management of young children is described. DESIGN: Contacts of an infant case of TB were identified and recommended to undergo baseline and post-exposure tuberculin skin tests (TST) as per Canadian TB standards. TST conversion was measured at least 8 weeks post exposure. Children aged <6 years were recommended to initiate preventive treatment with isoniazid (INH) until their post-exposure TST. Information on TST results and adherence to therapy were analysed from existing medical records. RESULTS: Overall, 17 TST conversions were documented among 732 contacts: both parents, two health care workers (HCWs) who provided close care, and several patients, visitors and one staff member without obvious close contact. Of 65 eligible children, 46% completed post-exposure therapy as recommended. The most common reasons for treatment failure were concern about side effects, perception of low risk and lack of physician support. CONCLUSION: This investigation suggests that all children, including infants, with cough and numerous bacilli or extensive pulmonary disease should be considered infectious. Health care provider education is necessary to resolve the observed low compliance with current post-exposure management guidelines.

Cross Infection↗
PubMed2005

Multi-dimensional phenotyping: towards a new taxonomy for airway disease.

All the real knowledge which we possess, depends on methods by which we distinguish the similar from the dissimilar. The greater the number of natural distinctions this method comprehends the clearer becomes our idea of things. The more numerous the objects which employ our attention the more difficult it becomes to form such a method and the more necessary. Classification is a fundamental part of medicine. Diseases are often categorized according to pre-20th century descriptions and concepts of disease based on symptoms, signs and functional abnormalities rather than on underlying pathogenesis. Where the aetiology of disease has been revealed (for example in the infectious diseases) a more precise classification has become possible, but in the chronic inflammatory diseases, and in the inflammatory airway diseases in particular, where pathogenesis has been stubbornly difficult to elucidate, we still use broad descriptive terms such as asthma and chronic obstructive pulmonary disease, which defy precise definition because they encompass a wide spectrum of presentations and physiological and cellular abnormalities. It is our contention that these broad-brush terms have outlived their usefulness and that we should be looking to create a new taxonomy of airway disease-a taxonomy that more closely reflects the spectrum of phenotypes that are encompassed within the term airway inflammatory diseases, and that gives full recognition to late 20th and 21st century insights into the disordered physiology and cell biology that characterizes these conditions in the expectation that these will map more closely to both aetiology and response to treatment. Development of this taxonomy will require a much more complete and sophisticated correlation of the many variables that make up a condition than has been usual to employ in an approach that encompasses multi-dimensional phenotyping and uses complex statistical tools such as cluster analysis.

Animals↗
PubMed2005

Identification of a progenitor of the CTX-M-9 group of extended-spectrum beta-lactamases from Kluyvera georgiana isolated in Guyana.

Chromosomal beta-lactamase genes (bla(KLUY)) from six Kluyvera georgiana strains isolated in Guyana were cloned and expressed in Escherichia coli. KLUY-1 exhibited 100% amino acid identity with the extended-spectrum beta-lactamase CTX-M-14. We also show that a 2.7-kb Kluyvera chromosomal region exhibits 99% nucleotide identity to a portion of In60 that includes bla(CTX-M-9).

Amino Acid Sequence↗
PubMed2003

Efficacy of a targeted, oral penicillin-based yaws control program among children living in rural South America.

Yaws is endemic in rural Guyana. An observational study was conducted to determine the efficacy of oral penicillin V therapy in treating skin lesions of yaws in children. In 1999, inhabitants of 7 rural villages near Bartica, Guyana, were screened for skin lesions of yaws. Cases were confirmed by serological testing. A control program was implemented in 2000: children < or =14 years old were screened, and those with active lesions were treated with oral penicillin V for 7-10 days. In 2001, children were rescreened and active cases were treated. Prevalence of yaws skin lesions fell from 5.1% (52 of 1020 children screened in 2000) to 1.6% (8 of 516 in 2001), a 71% drop. Sixteen (94%) of 17 children treated in 2000 and reassessed in 2001 had complete resolution of lesions. A targeted, oral penicillin-based treatment regimen can successfully treat dermatologic yaws in individual children and can decrease the prevalence of skin yaws in a community in which it is endemic. This information may aid in the implementation of additional control efforts.

Administration, Oral↗
PubMed2003

An adult model of exclusive viral wheeze: inflammation in the upper and lower respiratory tracts.

BACKGROUND: We have previously reported an experimental infection of young adults with a history of episodic and exclusive viral wheeze (EVW) using human coronavirus, in which 16 of 24 with EVW (15 atopic) and 11 of 19 healthy controls (seven atopic) developed a symptomatic cold with evidence of infection, but only those with EVW developed lower respiratory tract symptoms and increased airway responsiveness. OBJECTIVE: The aim of this study was to compare the EVW and control groups from this study for inflammatory changes occurring in the upper and lower respiratory tracts during the experimental infection, in particular, to determine whether eosinophil-driven inflammation was associated with EVW. METHODS: Nasal lavage and induced sputum were collected prior to inoculation (day 0) and 2, 4 and 17 days later. Differential cell counts were performed and supernatant was assayed for IL-8, IL-5, IFN-gamma, and eosinophilic cationic protein (ECP). RESULTS: There was no difference between the two groups in any measurement at baseline. In both groups, during colds the volume of nasal secretion increased as did leucocyte counts in both upper and lower respiratory tracts. A modest increase in nasal neutrophil count was seen in both EVW and control groups with symptomatic colds on day 2 (median (quartile) difference from baseline 5.4 (0.0, 11.0) and 1.8 (-1.1, 2.2)x10(4)/mL of secretions, respectively). The change in nasal neutrophil counts in all subjects correlated with nasal symptom scores. A significant relative increase in sputum differential neutrophil count was seen on day 4 in the EVW group with a cold but not in controls (mean difference (95% confidence interval) 20.4 (9.6, 31.1)% and 3.1 (-8.2, 14.5)%, respectively, P<0.01); however, this increase did not correlate with lower respiratory tract symptom scores. IL-8 increased in both the upper and lower respiratory tracts in both EVW and control subjects with colds, the largest change being seen on day 4 in the sputum of those with EVW (mean difference from baseline (95% confidence interval) 2.5 (0.55-4.46) ng/mL). Only modest changes were seen in IFN-gamma and no changes were seen in IL-5 or ECP. None of the results was influenced by the atopic status of the subjects in either group. CONCLUSIONS: EVW wheeze is characterized by neutrophilic inflammation in both the upper and lower respiratory tracts without eosinophilia (even in atopic subjects). IL-8 is likely to be an important chemokine in this process. Symptoms and airway responsiveness were correlated with change in neutrophils.

Common Cold↗
PubMed2003

Screening for problem drinking in older people referred to a mental health service: a comparison of CAGE and AUDIT.

The aim of the study was to evaluate the validity of the Alcohol Use Disorders Identification Test (AUDIT), the five-item version (AUDIT-5) and the CAGE as screening tests for problem drinking in mentally ill older people. The study was of prospective cross-sectional design with questionnaire survey and interview and included all consecutive referrals to an old age psychiatry service fulfilling inclusion criteria. Sensitivity, specificity and positive predictive values and areas under the receiver operating characteristic curves (AUROC) for the AUDIT, AUDIT-5, and CAGE were the primary outcome measures. Using clinical criteria as the gold standard, the AUDIT, AUDIT-5 and CAGE had AUROCs of 0.961, 0.964, and 0.780 respectively. The AUDIT-5 performed best of the three scales with a sensitivity of 75.0%, specificity of 97.2% and positive predictive value of 83.3% when using a 4/5 cut-point. The AUDIT-5 performed as well as the AUDIT and better than the CAGE in identifying problem drinking in this sample. The AUDIT-5 may be a useful addition to the specialist mental health assessment of older people.

Aged↗
PubMed2003

Perception of exercise induced asthma by children and their parents.

BACKGROUND: Exercise induced asthma (EIA) plays an important role in clinical evaluation. There has been little previous work validating EIA as reported directly by children and indirectly by their parents. AIMS: (1) To determine the strength of the association between children's symptoms of EIA and their physiological response to exercise in a laboratory setting. (2) To compare parents' perception of EIA with that of their children. (3) To seek factors influencing the perception of EIA. METHODS: Forty three asthmatic children and their parents answered a questionnaire, which included measures of symptom perception in EIA using visual analogue (VAS) and Likert scales. The children underwent a standardised treadmill exercise challenge, using spirometry to measure the physiological outcome, after which they and their parents independently completed the symptom scores. Twenty four subjects agreed to return for a second visit, in order to assess repeatability. RESULTS: The VAS and Likert scales were highly correlated. Children's symptom perception as measured by change in VAS scores related weakly to change in FEV(1) after exercise, and was unaffected by confounding factors such as age, gender, medication, and habitual exercise. Parents' perception of symptoms was unrelated to any physiological measure. There was no significant relation between parent and child VAS scores after exercise, and there was poor agreement between the Likert scale scores after exercise. The repeatability of the perception of change in FEV(1) after exercise was poor for both parents and children. CONCLUSION: Physicians should obtain reports of EIA from children rather than parents, but be aware of their limited accuracy and repeatability.

Adolescent↗
PubMed2003

Episodic viral wheeze in preschool children: effect of topical nasal corticosteroid prophylaxis.

BACKGROUND: The effect of prophylactic nasal corticosteroids on wheezing episodes associated with colds was investigated in a 12 week parallel group, double blind, randomised controlled trial in preschool children. METHODS: Data were collected from 50 children aged 12-54 months with a history of at least three episodes of wheeze associated with colds over the previous winter, but few or no interval symptoms; 24 were given one dose of fluticasone aqueous nasal spray (50 micro g) into each nostril twice daily and 26 received an indistinguishable placebo spray. Episodes of lower respiratory illness occurring within 2 days of the onset of a cold were identified from daily symptom diaries. The main outcome was nocturnal symptom score during the first 7 days of an episode. RESULTS: The groups were well balanced on entry except that the treatment group had a history of more prolonged episodes. During the trial there was no significant difference in the number of episodes in the treatment and control groups (27 and 37, respectively), in the severity of nocturnal symptoms (mean score 1.33 and 1.22, respectively, confidence interval of difference -0.24 to +0.47) or in daytime symptoms, activity or total scores during episodes. Compliance was estimated to be over 50% in 43 of the children. CONCLUSIONS: Nasal corticosteroid treatment does not prevent acute wheezy episodes associated with upper respiratory infections (common colds) in preschool children.

Administration, Intranasal↗
PubMed2003

The economic impact of preschool asthma and wheeze.

The aim of the present study was to determine the economic impact in the UK of wheezing disorders in preschool children. Health, societal and family-borne costs were calculated for a sample of 94 preschool children who attended hospital with a primary diagnosis of wheeze or asthma during 1998/1999. Sample costs were calculated using data from a structured interview schedule and from symptom diaries completed by trial parents, patients' general practice and hospital records, and hospital finance data. Health costs for 1-5-yr-olds in the UK were calculated using data from a postal population survey in the same region. It is estimated that 1-5-yr-old children with wheeze in the UK cost the health service a total of 53 million UK pounds (GBP). The greatest expenditure, 34 million GBP, was for primary care, representing 65.2% of total healthcare costs. Prescription costs represented 20.4% (11 million GBP) of total healthcare costs. Caring for preschool children with wheeze in the UK cost the health service 0.15% of its total budget in 1998/1999. The total costs to society of caring for the 0.88% of preschool children who attended hospital for asthma or wheeze in a year represented a further 2.6 million UK pounds. Primary prevention strategies at the population level promise more cost savings than any attempt at decreasing hospitalisations in those more severely ill.

Age Factors↗
PubMed2002

The role of house dust mite elimination in the management of childhood asthma: an unresolved issue.

Indoor allergens are likely to be direct environmental causes of asthma and mite exposure, and sensitization is the most important environmental risk factor for childhood asthma in temperate zones. Analagous to occupational asthma, allergen avoidance in asthmatic children sensitized and exposed to mite allergens is associated with a reduction in airway hyperresponsiveness and symptoms associated with improvement in lung function. The long-term effect of this strategy needs to be prospectively evaluated considering both the timing and duration of exposure, as well as the timing and duration of removal. In order to be successful, it is important to achieve and maintain a major reduction on allergen levels, for a long period of time.

Air Pollutants↗
PubMed2002

Parental education and guided self-management of asthma and wheezing in the pre-school child: a randomised controlled trial.

BACKGROUND: The effects on morbidity were examined of providing an educational intervention and a written guided self-management plan to the parents of pre-school children following a recent attendance at hospital for asthma or wheeze. METHODS: A prospective, randomised, partially blinded, controlled trial was designed at two secondary care centres. Over a 13 month period 200 children aged 18 months to 5 years at the time of admission to a children's ward or attendance at an accident and emergency department or children's (emergency) assessment unit (A&E/CAU) with a primary diagnosis of acute severe asthma or wheezing were recruited. 101 children were randomised into the control group and received usual care and 99 were assigned to the intervention group and received: (1) a pre-school asthma booklet; (2) a written guided self-management plan; and (3) two 20 minute structured educational sessions between a specialist respiratory nurse and the parent(s) and child. Subjects were assessed at 3, 6, and 12 months. The main outcomes were GP consultation rates, hospital re-admissions, and attendances at A&E/CAU. Secondary outcomes included disability score, caregivers' quality of life, and parental knowledge of asthma. RESULTS: There were no statistically significant differences between the two groups during the 12 month follow up period for any of the main or secondary outcome measures. CONCLUSIONS: These results do not support the hypothesis that the introduction of an educational package and a written guided self-management plan to the parents of pre-school children with asthma who had recently attended hospital for troublesome asthma or wheeze reduces morbidity over the subsequent 12 months.

Asthma↗