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Biomedical subjects

S Perry

Publications and source records attributed to S Perry.

At least 19 recordsLinked to original sources
PubMed2006

Conservation of Pitx1 expression during amphibian limb morphogenesis.

In contrast to the pattern of limb emergence in mammals, chicks, and the newt N. viridescens, embryos such as Xenopus laevis and Eleutherodactylus coqui initiate pelvic limb buds before they develop pectoral ones. We studied the expression of Pitx1 in X. laevis and E. coqui to determine if this paired-like homeodomain transcription factor directs differentiation specifically of the hindlimb, or if it directs the second pair of limbs to form, namely the forelimbs. We also undertook to determine if embryonic expression patterns were recapitulated during the regeneration of an amputated limb bud. Pitx1 is expressed in hindlimbs in both X. laevis and E. coqui, and expression is similar in both developing and regenerating limb buds. Expression in hindlimbs is restricted to regions of proliferating mesenchyme.

Animals↗
PubMed2005

Concordance of Helicobacter pylori infection among children in extended-family homes.

Helicobacter pylori is transmitted within households and high concordance is observed among siblings. To better understand the contributions of close interpersonal contact and family relatedness to transmission, we compared concordance of H. pylori infection among 241 sibling and non-sibling children aged 2-18 years in 68, predominantly low-income, Hispanic households with at least two nuclear families. Prevalence of H. pylori infection was 24%. Compared to children with no infected siblings or non-siblings and adjusting for age, odds of H. pylori infection were 1.2 (95% CI 0.52-2.9), 3.2 (95% CI 1.14-9.1), and 9.4 (95% CI 3.1-28.5) for children residing with at least one infected non-sibling, one infected sibling, and with at least one infected sibling and non-sibling, respectively. The study further implicates intersibling transmission as a pathway for H. pylori infection in childhood. In addition, living with a non-sibling in extended-family homes may contribute to infection risk but only in households with prevalent H. pylori infection within all family groups.

Adolescent↗
PubMed2005

Malaria prevention practices in Mopti region, Mali.

OBJECTIVES: To assess insecticide-treated nets (ITNs) use, other malaria prevention measures, knowledge of malaria and diffusion of information about ITNs by the National Malaria Control Programme (NMCP) in Mali. DESIGN: A descriptive cross-sectional study. SETTING: Four villages in Mopti region, Mali that had participated in the Mopti Regional Malaria Control Program (MRMCP) ITN Education Programme five years prior. PARTICIPANTS: Three hundred thirty nine randomly-selected households. Within each household, mothers of children one to nine years of age were interviewed regarding knowledge of malaria and prevention practices. RESULTS: Overall, 11% of households used ITNs, with 97% of these in two villages. Ninety eight percent of households used bednets, 22% used insecticide sprays and 39% used mosquito coils. Significant predictors of ITNs use were: head of household literacy, larger family size, Bambara ethnicity, hearing about the NMCP and hearing about ITNs from health agents. Reasons why ITNs were not used included not knowing anything about ITNs, cost and not having net impregnation services readily available in the village. Levels of knowledge concerning malaria disease, transmission and prevention varied amongst the four villages. ITN households had significantly higher levels of knowledge about malaria and its prevention. CONCLUSION: Five years after the implementation of the MRMCP, ITNs use was low and diffusion of malaria prevention information was unequal among villages. Future efforts in improving the programme must recognise these differences in knowledge and ITNs utilisation and make village-specific changes that are acceptable for each village.

Adolescent↗
PubMed2005

QuantiFERON-TB predicts tuberculin skin test boosting in U.S. foreign-born.

SETTING: Santa Clara County, Northern California. OBJECTIVE: To characterize agreement of tuberculin skin test (TST) and QuantiFERON-TB (QFT) with repeated testing. DESIGN: Fifty-two subjects participating in an ongoing prospective study of infectious disease transmission were tested by TST and QFT at two home visits 3 months apart. Boosting was defined as reclassification of TST from negative to positive. Agreement and reproducibility of TST and QFT were assessed using kappa and McNemar statistics. RESULTS: Of 48 individuals completing all tests, 75% were foreign-born (92% Latin America) and 58% were BCG-vaccinated. Initial TST and QFT were positive in 13 (27%) and 21 (44%), respectively, with an overall agreement of 67% (K = 0.29). Ten (29%) of 35 initial TST-negative reactions boosted, nine of whom were BCG-vaccinated subjects. Boosting occurred in eight (67%) of 12 subjects who were initially QFT-positive/TST-negative. Compared to the second TST, initial QFT had a relative post-test probability of 76% (95% CI 0.58-0.95); boosting accounted for 8/16 (50%) of initial testing discordances. CONCLUSION: Positive QFT in the setting of negative TST frequently anticipates a TST boost. This finding helps explain discordance between the two tests and may provide an alternative to serial TST testing.

Adolescent↗
PubMed2005

Integration of microscopy and serodiagnostic tests to screen for active tuberculosis.

SETTING: University of California San Diego Medical Center, USA. OBJECTIVE: To create a simple screening strategy for tuberculosis (TB) that includes antibody detection assays to improve the accuracy of microscopic examination of sputum for acid-fast bacilli (AFB smear). METHODS: Serum samples were obtained from 190 patients suspected of having active TB. TB diagnosis was established by Mycobacterium tuberculosis culture. HIV status was determined by commercial serologic tests. IgG antibody levels were measured by ELISA using purified M. tuberculosis antigens. Data from 130 randomly selected patients were used to develop a screening strategy; data from the remaining 60 patients were used for validation. RESULTS: AFB smear had 70% sensitivity and 88% specificity. In algorithms integrating single or multi-antigen ELISA with AFB smear and HIV results, the sensitivity improved over each test alone. The algorithm that included a four-antigen ELISA (38 kDa antigen, lipoarabinomannan, MPT-64 and glutamine synthase) had a sensitivity of 93% and a specificity of 76%. Compared to AFB smear, the sensitivity of the algorithm was significantly higher, while the specificity was not statistically different. CONCLUSION: This study demonstrates that a screening strategy can be created by integrating multi-antigen ELISA with AFB smear and HIV testing.

Adult↗
PubMed2004

The facilitating factors and barriers influencing change in dental practice in a sample of English general dental practitioners.

AIM: The objective of this study was to investigate the barriers and facilitators to change in dental practices among a sample of general dental practitioners (GDPs) from three regions of England. METHOD: In-depth face-to-face interviews with 60 GDPs were undertaken. The sample was selected from a group of 317 GDPs who had completed a questionnaire in the first phase of this study. The participants were selected to reflect diversity regarding the number and extent of self-reported changes reported in the questionnaire, and personal and practice characteristics. Of the 92 attempted contacts, 60 (65%) of the interviews were successfully completed. The interview schedule formed the basis of the interview. All the interviews and notes were transferred on to NUD*IST QSR version 4, a qualitative analysis package. RESULTS: No single factor was identified as being more important than another in facilitating change. The main facilitators for change were: financial factors, regular patient attendance, particularly a core patient group, staff loyalty, having regular staff meetings and open communication and having access to peer support. The main barriers to change were the reverse of the facilitators plus not having a financial stakehold in the practice. CONCLUSIONS: A range of factors were identified as influencing change in general dental practice. These include GDPs' attitudes and experience of change, patient factors, organisational issues, contact with peers and access to appropriate training courses.

Adult↗
PubMed2004

The prevalence and nature of recent self-reported changes in general dental practice in a sample of English general dental practitioners.

OBJECTIVE: To determine the extent and types of change in seven domains of dental practice in a sample of English general dental practitioners (GDPs). METHODS: A postal questionnaire was sent to 561 GDPs on the dental lists of three health authorities in diverse regions of England. Information collected included demographic details on personal and practice characteristics, self-rating of amount of change in the seven domains of practice and factors influencing change. RESULTS: The response rate was 60%. Fifty-six per cent of the sample were under 40 years old. Over a third of respondents reported "changing a lot or completely" certain clinical activities, practice management arrangements and practice amenities. The highest self-reported level of change was in clinical activities. Of the GDPs who reported changing their clinical activities, 56% reported an increase in preventive care, followed by crown and bridge (44%), periodontics (44%) and endodontics (43%). Practice management rated second in the mean rank scores for self-reported change. The main changes reported were the introduction of computer systems and employment of practice managers. A sizeable percentage (66%) reported increasing the amount of information they provided to patients and the time spent discussing care. Quality assurance activities were the area of practice least likely to have changed over a 5-year period. Over half the sample reported not being involved in any quality assurance activities in the previous 5 years. Those respondents who were younger, had a postgraduate qualification and earned more than 20% of their income from private practice reported higher levels of change. CONCLUSIONS: General dental practitioners' work patterns are dynamic and appear to be responding to changing needs and demands on their service. The main changes were in the types of clinical procedures being carried out. The low prevalence of changes reported in auditing and peer review activities needs to be investigated further.

Adult↗
PubMed2003

Reliability and validity of the SF-36 in HIV-infected homeless and marginally housed individuals.

OBJECTIVE: To assess the reliability and validity of the Short-Form 36 (SF-36) health survey as a health status indicator among HIV-infected homeless and marginally housed (HMH) individuals. METHODS: Between July 1996 and May 2000, a sample of HMH individuals completed interviews that included the SF-36. Responses to the SF-36 were analyzed for missing data, range, internal consistency, and construct validity. RESULTS: Among 330 individuals interviewed, 83% were male, 43% were African-American, and the median age was 39 years. All internal consistency reliability coefficients exceeded 0.70, all item-scale correlations exceeded 0.40, all items were more strongly correlated with their hypothesized scale than any other scale, and all reliability coefficients exceeded inter-scale correlations for the same scale. Three of four physical health scales were significantly associated with CD4 cell count and HIV viral load. All scales were significantly associated with depression. DISCUSSION: We found that scales were internally consistent, items correlated to an acceptable degree with their hypothesized scales, items were distinct from other scales, physical scales were associated with CD4 cell count and viral load, and all scales were associated with depression. These analyses provide evidence for the reliability and validity of the SF-36 as a measure of health status in HIV-positive HMH individuals.

Adult↗
PubMed2002

The strong ion gap does not have prognostic value in critically ill patients in a mixed medical/surgical adult ICU.

OBJECTIVE: To examine whether the strong ion gap (SIG) or standard base excess corrected for abnormalities of serum chloride and albumin (BE(UA)) can predict outcome and to compare the prognostic abilities of these variables with standard base excess (SBE), anion gap (AG), pH, and lactate, the more traditional markers of acid-base disturbance. DESIGN: Prospective, observational study. SETTING: University teaching hospital, general adult ICU. PATIENTS: One hundred consecutive patients on admission to the ICU. MEASUREMENTS AND RESULTS: The anion gap (AG) was calculated and corrected for abnormal serum albumin (AG(corrected)). Serum lactate was measured and SBE, BE(UA), SIG, and APACHE II scores calculated for each patient. 28-day survival was recorded. There was a significant difference between the mean APACHE II (P < 0.001), SBE (P < 0.001), lactate (P = 0.008), AG (P = 0.007), pH (P < 0.001), and BE(UA) (P = 0.009) of survivors and non-survivors. There was no significant difference between the mean SIG (P = 0.088), SIDeff (P = 0.025), and SID app (P = 0.254) between survivors and non-survivors. The pH and SBE demonstrated the best ability of the acid-base variables to predict outcome (AUROC curves 0.72 and 0.71, respectively). Neither of these were as good as the APACHE II score (AUROC 0.76) CONCLUSION: Traditional indices of SBE, BE(UA,) lactate, pH, AG, and APACHE II all discriminated well between survivors and non-survivors. In this group of patients the SIG, SIDeff, and SIGapp appear to offer no advantage in prediction of outcome and their use as prognostic markers can therefore not be advocated.

APACHE↗
PubMed2002

Prevalence of faecal incontinence in adults aged 40 years or more living in the community.

BACKGROUND: Prevalence studies of faecal incontinence in the general population are rare and the impact of faecal incontinence on quality of life has not been previously addressed. AIMS: To establish the prevalence of faecal incontinence in adults in terms of frequency of leakage, degree of soiling, and level of impact on quality of life. METHODS: In a cross sectional postal survey, 15 904 adults aged 40 years or more (excluding residents of nursing and residential homes) were selected randomly by household from the Leicestershire Health Authority patient register. Participants were asked to complete a confidential health questionnaire. Major faecal incontinence was defined as soiling of underwear or worse with a frequency of several times a month or more. Respondents were also asked if bowel symptoms had an impact on their quality of life. RESULTS: From a total sample of 10 116 respondents, 1.4% reported major faecal incontinence and 0.7% major faecal incontinence with bowel symptoms that had an impact on quality of life. Major faecal incontinence was significantly associated with a lot of impact on quality of life (odds ratio 12.4, 95% confidence interval 7.5-20.6). Incontinence was more prevalent and more severe in older people but there was no significant difference between men and women. CONCLUSIONS: This study has confirmed that faecal incontinence is a fairly common symptom, particularly in older people. Faecal incontinence in men has received little attention in the past and the results from this study indicate that it is as much of a problem in men as it is in women while the level of unmet need in this group is high. Estimates of need for health care for this symptom should be multidimensional and assess both the severity of symptoms and the impact it has on quality of life.

Adult↗
PubMed2001

The clinical pharmacokinetics of a new pharmacokinetically enhanced formulation of amoxicillin/clavulanate.

BACKGROUND: A new oral pharmacokinetically enhanced formulation of the broad-spectrum antibiotic amoxicillin/clavulanate has been developed to provide more effective therapy against resistant pathogens than is provided by currently available formulations by maintaining therapeutically useful plasma amoxicillin concentrations for a longer period after dosing. OBJECTIVE: This study explored the pharmacokinetics of the new oral formulation of amoxicillin/clavulanate in healthy male and female subjects. METHODS: A single oral dose of pharmacokinetically enhanced amoxicillin/clavulanate (2000/125 mg; 16:1 ratio) was administered to subjects at the start of a meal. After dosing, blood samples were collected at frequent intervals up to 12 hours, and plasma was assayed for amoxicillin and clavulanate concentrations using validated procedures. The new formulation consisted of 1 layer of immediate-release amoxicillin and clavulanate and another of sustained-release amoxicillin in a proportion such that for an amoxicillin minimum inhibitory concentration (MIC) of 4 microg/mL, the time above the MIC (T >MIC) would be approximately > or = 40% over a 12-hour dosing interval. RESULTS: The study enrolled 24 and 31 healthy male and female subjects, respectively. Their mean age was 35 years (range, 18-58 years) and mean body weight was 69 kg (range, 51-86 kg). After the expected sharp peak in plasma amoxicillin concentration, there appeared to be a slower decline with the pharmacokinetically enhanced formulation than is usually seen with conventional formulations, and there was evidence of a second amoxicillin absorption phase. The mean T >MIC for an amoxicillin MIC of 4 microg/mL was 49.4% of a 12-hour dosing interval, a value that cannot be achieved with existing approved doses and formulations of amoxicillin/clavulanate. By 12 hours, plasma amoxicillin concentrations were very low (approximately 0.05 microg/mL), suggesting no expectation of notable dose-to-dose accumulation on repeat dosing with a BID regimen. The terminal half-lives of amoxicillin (1.27 hours) and clavulanate (1.03 hours) with the new formulation were similar to those of existing formulations of amoxicillin/clavulanate. No deaths or serious adverse events were reported. CONCLUSIONS: The enhanced pharmacokinetic profile of amoxicillin/clavulanate seen in this study suggests that this formulation is likely to be highly effective for the oral treatment of infections caused by bacteria--including beta-lactamase-producing organisms--and strains with amoxicillin MICs < or = 4 microg/mL.

Adolescent↗
PubMed2001

Discrimination functions: can they be used to classify singing voices?

Researchers long have searched for invariant acoustic features that can be used to identify singing voice categories or even individual singers. Few researchers have examined how listeners perceive singing voice categories or individual voices. Timbre, the most studied perceptual dimension of the singing voice, is generally believed to vary systematically between singing voice categories but is often assumed to be invariant with an individual singer. To test this assumption, 2 mezzo-sopranos and 2 sopranos were recorded singing the vowel /a/ on the pitches A3, C4, G4, B4, F5, and A5. Trials of three stimuli were constructed. Two of the three stimuli in each trial were produced by the same singer at two different pitches (X1 and X2), while the third stimulus was produced by a different singer (Y). Three X1X2 conditions were created: (1) G4, B4; (2) C4, F5; and (3) A3, A5. For each singer and each condition, Y was varied across the three remaining singers and across all six pitches. Experienced and inexperienced listeners were asked to identify which stimulus was produced by the "odd" person. The ability to correctly choose the odd person varied greatly depending on pitch factors, suggesting that the traditional concept of an invariant timbre associated with a singer is inaccurate and that vocal timbre must be conceptualized in terms of transformations in perceived quality that occur across an individual singer's range and/or registers.

Adult↗
PubMed2000

The role of clinical suspicion in evaluating a new diagnostic test for active tuberculosis: results of a multicenter prospective trial.

CONTEXT: In laboratory trials, nucleic acid amplification tests for the diagnosis of tuberculosis (TB) are more accurate than acid-fast bacilli (AFB) smear microscopy and are faster than culture. The impact of these tests on clinical diagnosis is not known. OBJECTIVE: To assess the performance of a nucleic acid amplification test, the enhanced Mycobacterium tuberculosis Direct (E-MTD) test, against a uniform clinical standard stratified by level of clinical suspicion. DESIGN: Prospective multicenter trial conducted between February and December 1996, documenting the clinical suspicion of TB at enrollment and using final comprehensive diagnosis as the criterion standard. SETTING: Six urban medical centers and 1 public health TB clinic. PATIENTS: A total of 338 patients with symptoms and signs consistent with active pulmonary TB and complete clinical diagnosis were stratified by the clinical investigators to be at low (< or =25%), intermediate (26%-75%), or high (>75%) relative risk of having TB. MAIN OUTCOME MEASURES: Sensitivity, specificity, and positive and negative predictive values of the E-MTD test in clinical suspicion of groups with low (n = 224); intermediate (n = 68); and high (n = 46) clinical suspicion of TB. RESULTS: Based on comprehensive clinical diagnosis, sensitivity of the E-MTD test was 83%, 75%, and 87% for low, intermediate, and high clinical suspicion of TB, respectively, and corresponding specificity was 97%, 100%, and 100% (P = .25). Positive predictive value of the E-MTD test was 59% (low), 100% (intermediate), and 100% (high) compared with 36% (low), 30% (intermediate), and 94% (high) for AFB smear. Corresponding negative predictive values were 99%, 91%, and 55% [corrected] (E-MTD test) vs 96%, 71%, and 37% (AFB smear). CONCLUSIONS: For complex diagnostic problems like TB, clinical risk assessments can provide important information regarding predictive values more likely to be experienced in clinical practice. For this series, a clinical suspicion of TB was helpful in targeting areas of the clinical spectrum in which nucleic acid amplification tests can make an important contribution.

Adult↗
PubMed2000

Non-invasive assessment of rejection in pediatric transplant patients: serologic and echocardiographic prediction of biopsy-proven myocardial rejection.

BACKGROUND: Cardiac allograft rejection is a multifocal immune process that is currently assessed using biopsy-guided histologic classification systems (International Society for Heart and Lung Transplantation). Cardiac troponin T and I are established serologic markers of global myocyte damage. The use of load-independent measures of contractility have also been shown to accurately assess the presence of ventricular dysfunction. Little is known about their utility in accurately predicting rejection in the pediatric age group. We undertook the present study to compare rejection grade with echocardiographic and serologic estimates of transplant rejection-related myocardial damage. METHODS: We compared histologic rejection grades (0 to 4) with patient characteristics, echocardiographic measurements, catheterization measurements, and biochemical markers for 86 evaluations in 37 transplant recipients at Children's Hospital. RESULTS: In univariate analyses, biopsy scores correlated (p < 0.05) inversely with left ventricular systolic function (shortening fraction) and contractility (stress velocity index, SVI), and directly with mitral E-wave amplitude. In multivariate analyses, lower contractility and higher mitral E-wave amplitude remained significantly (p < or = 0.01) associated with rejection (SVI, p = 0.002, odds ratio = 0.393; E wave, p = 0.0002, odds ratio = 228). Most rejection episodes were associated with elevation of biochemical markers of myocardial injury. Although troponin I was weakly associated with differences between rejection grades (p = 0.034), troponin T, creatine kinase-MB fraction, and C-reactive protein did not differ with biopsy-rejection scores. Serum markers had a poor predictive capacity for biopsy-detected rejection. Troponin T and I did correlate with increased left ventricular wall thickness and mass. CONCLUSION: Progressively depressed left ventricular contractility and diastolic function are found with worsening pediatric heart transplant rejection-biopsy score; however, sensitive and specific serum markers do not correspond to the degree of active myocardial injury. The use of echocardiographic measures of contractility is associated with a specificity of 91.8% but low sensitivity of 66.7%. Overall we found poor concordance between serum markers and grade of rejection. It is unclear whether myocardial injury as assessed by serum markers, echocardiography, or histologic scoring is more important for assessment of acute rejection or long-term outcome, but it does not appear that serum and tissue markers of rejection can be used interchangeably.

Adolescent↗
PubMed2000

Development, implementation and evaluation of a new nurse-led continence service: a pilot study.

The Leicestershire Medical Research Council (MRC) Incontinence Study is a series of interrelated studies exploring the epidemiology of urinary symptoms, including incontinence, and evaluating service provision and treatment options for these symptoms. This paper describes one aspect of the Leicestershire MRC Incontinence Study, namely the development, implementation and evaluation of a new nurse-led continence service. When developing a new service it is important to determine its acceptability and suitability to the target population. The new mode of service delivery was dependent on specially trained Continence Nurse Practitioners (CNP) delivering predefined evidence-based treatment interventions. Objective and subjective outcome measures were used to evaluate the service. The service was shown to be effective in reducing urinary symptoms and led to high levels of patient satisfaction. This service is currently being evaluated in a randomized controlled trial.

Evidence-Based Medicine↗