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J Todd

Publications and source records attributed to J Todd.

At least 19 recordsLinked to original sources
PubMed2002

Absolute levels and ratios of proinflammatory and anti-inflammatory cytokine production in vitro predict clinical immunity to Plasmodium falciparum malaria.

The relationship between malaria-related outcomes and cytokine production in whole blood cultures associated with cellular immune responses and immunity to Plasmodium falciparum malaria was examined in a study in southern Ghana. Production of malaria-specific interferon (IFN)-gamma was associated with reduced risk of fever and clinical malaria. Protective IFN-gamma responses were induced by live schizonts but not by dead parasites. Production of malaria-specific tumor necrosis factor (TNF)-alpha was associated with reduced risk of fever during follow-up. Baseline levels of TNF-alpha and phytohemagglutinin (PHA)-induced interleukin (IL)-10 were positively associated with hemoglobin concentration. IL-12 production was associated with reduced risk of parasitemia. PHA-induced transforming growth factor-beta production was associated with reduced risk of fever during follow-up. High ratios of proinflammatory to anti-inflammatory cytokines were associated with increased risk of fever and higher hemoglobin concentrations. Thus, absolute levels and ratios of proinflammatory and anti-inflammatory cytokines influence susceptibility to infection, clinical disease, and anemia. These data contradict data from cross-sectional clinical studies and indicate a need for detailed analysis of the relationship between cellular immunity to malaria and resistance to disease.

Adolescent↗
PubMed2002

Myopia in secondary school students in Mwanza City, Tanzania: the need for a national screening programme.

BACKGROUND/AIMS: The prevalence of significant refractive errors and other eye diseases was measured in 2511 secondary school students aged 11-27 years in Mwanza City, Tanzania. Risk factors for myopia were explored. METHODS: A questionnaire assessed the students' socioeconomic background and exposure to near work followed by visual acuity assessment and a full eye examination. Non-cycloplegic objective and subjective refraction was done on all participants with visual acuity of worse than 6/12 in either eye without an obvious cause. RESULTS: 154 (6.1%) students had significant refractive errors. Myopia was the leading refractive error (5.6%). Amblyopia (0.4%), strabismus (0.2%), and other treatable eye disorders were uncommon. Only 30.3% of students with significant refractive errors wore spectacles before the survey. Age, sex, ethnicity, father's educational status, and a family history of siblings with spectacles were significant independent risk factors for myopia. CONCLUSION: The prevalence of uncorrected significant refractive errors is high enough to justify a regular school eye screening programme in secondary schools in Tanzania. Risk factors for myopia are similar to those reported in European, North-American, and Asian populations.

Adolescent↗
PubMed2001

Do loudness cues contribute to duration mismatch negativity reduction in schizophrenia?

The present study explored duration mismatch negativity (MMN) reduction in schizophrenia. Duration MMN studies usually employ tones of very short duration (< 200 ms). For stimuli < 200 ms in duration, an increment in duration is accompanied by an increase in perceived loudness. It was previously proposed that the effectiveness of duration MMN in revealing MMN reduction in schizophrenia might be explained by patients being insensitive to loudness cues and duration increments. In this study we equated loudness cues in a typical duration MMN paradigm and explored the effect of this manipulation on MMN amplitude reduction in schizophrenia. The manipulation had little effect on a healthy comparison group but had a marked effect on the MMN generated in the patient group who produced a significantly smaller MMN response to the regular duration deviant than to that in the equated loudness condition. This result was interpreted as demonstrating that patients exhibit a very marked insensitivity to duration increments.

Acoustic Stimulation↗
PubMed2001

Hospital reconfiguration. Going places.

Two major hospital moves in Lanarkshire were completed smoothly by predicting the number of emergency admissions likely over the crucial periods and involving GPs and all the hospitals concerned. An analysis of emergency admissions was one factor in deciding which days the moves should take place on. A workshop after the first move was finished proved important.

Continuity of Patient Care↗
PubMed2001

Subliminal ultraviolet-B irradiation for the prevention of vitamin D deficiency in the elderly: a feasibility study.

AIM: To investigate whether daily subliminal ultraviolet-B irradiation in elderly subjects can maintain a normal vitamin D status. MATERIAL AND METHODS: In an open, uncontrolled study, 10 residents (four men and six women), mean age on entry of 83 years (range 65-97 years), from a residential nursing home in County Durham, England, were exposed daily to an artificial source of ultraviolet-B radiation equivalent to 15 min of summer sunshine. The change in plasma 25-hydroxyvitamin D levels following irradiation was measured. RESULTS: Improvement in the vitamin D status of the elderly residents was achieved with no change in their routine and with no intervention on the part of carers. CONCLUSIONS: On the basis of this small pilot study we conclude that subliminal ultraviolet-B irradiation may be effective in maintaining vitamin D status in elderly people at a lower cost than that of using oral vitamin D supplementation. Further controlled studies are needed before this technique can be recommended to change health policy with regard to the vitamin D status of institutionalised elderly people.

Aged↗
PubMed2001

Dietary trends among Scottish schoolchildren in the 1990s.

BACKGROUND: In recent years, healthy eating messages have sought to highlight the advantages of a healthy balanced diet, but there is little evidence that the recommendations have been translated into sustained behavioural change. In Scotland, the national diet has become a major focus in key policy documents, and the diet of children and young people has been consistently highlighted as an area of particular concern. This paper reports on dietary trends among Scottish schoolchildren during the 1990s. METHODS: Data were collected from a representative sample of Scottish schoolchildren as part of the WHO Cross-national Health Behaviour of School-aged Children (HBSC) study. Three consecutive national surveys were undertaken in Scotland, in 1990, 1994 and 1998, using self-completion food frequency questionnaires with 11-, 13- and 15-year-old school pupils. RESULTS: Between 1990 and 1998, fruit and vegetable consumption increased among Scottish schoolchildren, especially among girls, but levels of consumption fell below current dietary recommendations. There has been a concomitant increase in consumption of high-fat and high-sugar foods, and consumption of these foods is higher among boys and children from lower socio-economic groups. CONCLUSION: The findings emphasize the need for continued health promotion efforts to improve the diet of schoolchildren in Scotland especially among lower socio-economic groups.

Adolescent↗
PubMed2001

Prevalence of HIV and Chlamydia trachomatis infection in 15--19-year olds in rural Tanzania.

OBJECTIVE: To estimate the prevalence of HIV and Chlamydia trachomatis (CT) infections amongst adolescents in rural Mwanza Region, Tanzania and their association with demographic variables. DESIGN: Population-based cross-sectional survey. METHODS: All 15--19-year olds living in households selected by random cluster sampling were invited to participate. After interview, urine was tested for HIV and CT. RESULTS: 9445 15--19-year olds were enrolled. HIV prevalence was 0.6% (95% CI: 0.4--0.8%) in males and 2.4% (95% CI: 2.0--2.8%) in females, and increased steeply with age (trend: P < 0.006 and P < 0.001, respectively). After adjustment for age, risk of HIV infection was significantly associated with female sex (OR=4.3), never having been to primary school in males (OR=2.7), and current symptoms of genital discharge (OR=2.3) or genital ulcer (OR=5.3) in females. The prevalence of CT was 1.0% (95% CI: 0.8--1.4%) in males and 2.4% (95% CI: 2.0-2.9%) in females. After adjustment for age, CT infection was associated with female sex (OR=2.4), reported current symptoms of STD (males OR=2.5, females OR=1.9) and positive leucocyte esterase (LE) test (males OR=3.1, females OR=2.6). Eighty-two percent of males and 79% of females with CT were asymptomatic. There was no association between CT and HIV infection in either sex. CONCLUSIONS: There is a high prevalence of HIV and CT amongst adolescents, especially young women, in this rural population, highlighting the need for effective interventions to improve adolescent reproductive health. The high rates of asymptomatic infection imply that innovative strategies are needed to reach and treat young people with STD.

Adolescent↗
PubMed2001

How many patients with a sexually transmitted infection are cured by health services? A study from Mwanza region, Tanzania.

OBJECTIVES: To estimate the proportion of symptomatic patients with a bacterial sexually transmitted infection (STI) cured by primary health care services in Mwanza Region, Tanzania, and to compare the cure rate achieved by health centres before and after the introduction of improved STI treatment services. METHODS: A model was used that describes the different hurdles patients with an STI take before they can be considered cured by the health services. The values for the input parameters for the model were taken from different studies. Data from an intervention trial as well as from a population-based study on male urethritis were used to estimate the proportion of symptomatic patients with an STI who seek care from a health centre. An observational study in four health centres where improved STI treatment services had been introduced provided estimates of the proportions of patients with an STI correctly diagnosed and treated. Patients who returned to the health centres after 1 week were interviewed about compliance. An estimate of the efficacy of treatments prescribed for STIs in health centres before the introduction of improved STI services was obtained from a study on prescription patterns for genital discharge syndrome (GDS) and genital ulcer disease (GUD). RESULTS: It was estimated that in the catchment area of health centres offering improved STI services, 51-72% of patients with STI symptoms sought care from those health centres. About 76-85% of cases were correctly diagnosed, and of these 69-80% received efficacious treatment. Compliance with full treatment was estimated at 84%. The estimated overall cure rate achieved by the health centres offering improved STI services ranged between 23 and 41%. The proportion of symptomatic STI patients who attended a health centre before improved STI services were introduced was estimated at 39%. The estimated efficacy of the treatments prescribed was 28%. The overall cure rate achieved by these health centres was less than 10%. CONCLUSIONS: When assessing the performance of STI case detection and management all steps have to be taken into account that are taken by patients with an STI before they can be considered cured by the health services. The intervention to improve STI services in Mwanza Region has resulted in an improvement of the cure rate of STIs achieved by primary health care centres.

Adolescent↗
PubMed2001

Pott's puffy tumor and epidural abscess arising from dental sepsis: a case report.

OBJECTIVE: To present an unusual case of two uncommon cranial complications of frontal sinusitis: Pott's puffy tumor and epidural abscess arising from frontal sinusitis of dental origin, and also two systemic complications of sinusitis: septicemia and empyema, all occurring in an immunocompetent patient. STUDY DESIGN: A 21-year-old man presented with a scalp swelling and epidural abscess. Magnetic resonance imaging and computed tomographic scans revealed unilateral opacification of the frontal sinus and an epidural abscess with a direct connection to the scalp abscess. Further history revealed that his symptoms occurred coincidentally with a tooth extraction 2 months before, and he was hospitalized soon after the tooth extraction for sepsis and a lung abscess. METHODS: A combined neurosurgical and otolaryngologic approach was required to treat the sinusitis and the associated epidural and scalp abscess. RESULTS: Cultures returned as Streptococcus intermedius from all three sites. The patient was free of disease at the 3-month follow-up. CONCLUSIONS: Odontogenic maxillary sinusitis is well documented; however, there is little reported of frontal sinusitis arising from dental disease. The prevalence of sinusitis of dental origin will be reviewed, including the microbiology of this particularly virulent organism that persisted despite earlier treatment with ampicillin. Also, the current thoughts on management of these cases will be discussed with particular reference to local therapy for sinusitis in addition to systemic treatment with antibiotics.

Abscess↗
PubMed2001

Risk factors for active syphilis and TPHA seroconversion in a rural African population.

OBJECTIVES: Syphilis is an important cause of morbidity in sub-Saharan Africa, and a cofactor for the sexual transmission of HIV. A better understanding of the prevalence and risk factors of syphilis in African populations would help to formulate effective interventions for its prevention and treatment. METHODS: The prevalence and incidence of syphilis were obtained from a cohort recruited in Mwanza, Tanzania. Two unmatched case-control studies nested within the cohort provide information on potential risk factors. RESULTS: The prevalence of active syphilis (TPHA positive and RPR positive any titre) was 7.5% in men and 9.1% in women, but in youths (aged 15-19 years) the prevalence was higher in women (6.6%) than in men (2.0%). The incidence of TPHA seroconversion was highest in women aged 15-19 at 3.4% per year, and around 2% per year at all ages among men. A higher prevalence of syphilis was found in those currently divorced or widowed (men: OR=1.61, women: OR=2.78), and those previously divorced or widowed (men: OR=1.51, women: OR=1.85). Among men, prevalence was associated with lack of circumcision (OR=1.89), traditional religion (OR=1.55), and reporting five or more partners during the past year (OR=1.81) while incidence was associated with no primary education (OR=2.17), farming (OR=3.85), and a self perceived high risk of STD (OR=3.56). In women, prevalence was associated with no primary education (OR=2.13), early sexual debut (OR=1.59), and a self perceived high risk of STD (OR=3.57), while incidence was associated with living away from the community (OR=2.72). CONCLUSION: The prevalence and incidence of syphilis remain high in this rural African population. More effort is needed to promote safer sexual behaviour, and to provide effective, accessible treatment. The high incidence of syphilis in young women calls for sexual health interventions targeted at adolescents.

Adolescent↗
PubMed2001

The interrelation of HIV, cervical human papillomavirus, and neoplasia among antenatal clinic attenders in Tanzania.

OBJECTIVES: To determine the prevalence and interrelation of cervical human papillomavirus (HPV) genotypes, squamous intraepithelial lesions (SIL), HIV, and other reproductive tract infections (RTIs) among urban antenatal clinic attenders in Mwanza, Tanzania. METHODS: Genital swabs were collected from 660 pregnant women and tested for a range of RTIs and for cervical cytology. Cervical HPV-DNA was detected by PCR and genotyped. HIV and syphilis serologies were performed. RESULTS: HPV prevalence was 34% (209/612 women). Of the 144 typeable samples, 83% were high risk (HR-HPV) oncogenic strains (56% HPV 16 related types). SIL was detected in 43 women (7%), with high grade SIL in 3%. There was a high prevalence of HIV (15%), and of any RTI (83%). Genital warts were detected in 20 women (3%). HPV infection was associated with some behavioural factors (short duration of relationship, single status, not using condoms) and gonorrhoea. There was no overall association between HPV and HIV (OR=1.02, 95% CI 0.6-1.6), but a non-significant trend towards a stronger association with HR-HPV in women aged 15-19 (OR=2.79, 95% CI 0.8-9.5) and women aged > or =30 (OR=3.20, 95% CI 0.7-15). SIL was associated with HPV (OR=3.66, 95% CI 1.9-7.0), but not significantly with HIV (OR=1.54, 95% CI 0.7-3.4). Prevalence of SIL was higher among women dually positive for HPV/HIV compared to HPV infection only (21% v 12%), although this difference was not statistically significant (p=0.17). CONCLUSIONS: HPV infection was highly prevalent in this young antenatal population. The association of HIV with HR-HPV types in older women may suggest that the principal HIV/HPV interaction in this population is for HIV to upregulate HPV persistence, leading to subsequent development of SIL.

Adolescent↗
PubMed2001

Building social relationships through valued roles: three older adults and the community membership project.

The experiences of three older adults with developmental disabilities highlight ways in which social relationships can be nourished through the establishment of community roles. Members of the Community Membership Project of the Center on Aging and Community used paid community builders working individually with older persons who had developmental disabilities in order to help them obtain positive, valued social roles and relationships with nondisabled community members. As a means to this end, participants were supported to engage in community activities corresponding to the interests and talents discovered in an initial period of exploration. Stories of these community builders' work illustrate the intentional strategies and concerted effort necessary to create community connections and meaningful relationships.

Community Networks↗
PubMed2000

Do perceived loudness cues contribute to duration mismatch negativity (MMN)?

This study explored the contribution of perceived loudness cues to mismatch negativity produced in response to a 125 ms duration deviant tone among a regular sequence of 50 ms standard tones. Each individual was required to adjust the intensity of a 125 ms tone until it matched the perceived loudness of a 50 ms tone. The mismatch negativity produced to the duration deviant presented at the same intensity as the standard was contrasted with that produced to the same deviant at each individual's perceived loudness equivalence. Despite detectable difference perceived loudness (approximately 1.3 dB), adjusting the intensity of the deviant tone did not significantly reduce mismatch negativity amplitude to the duration deviant. Results are discussed with reference to temporal window of integration.

Acoustic Stimulation↗
PubMed2000

Auditory sensory memory in schizophrenia: inadequate trace formation?

This study explored duration mismatch negativity reductions observed in individuals with schizophrenia, in particular, the relationship to behavioural measures of temporal discrimination and two event-related potential (ERP) components occurring during the first phase of auditory sensory memory. Twenty-two patients with a DSM-IV and ICD-10 diagnosis of schizophrenia and 25 healthy comparison volunteers participated in a behavioural and an ERP testing session. Both groups performed equivalently on behavioural estimates of filled interval duration discrimination and gap detection. In contrast, electrophysiological measures revealed a significant reduction in patients' duration mismatch negativity and a significant difference in patients for the pattern of N100 facilitation over short stimulus onset asynchronies. Whilst behavioural results indicate intact temporal processing of filled intervals and equal temporal resolution limits in schizophrenia, both ERP measures indicated differences in auditory processing that may be traced to activity occurring during the first 250 ms. Results highlight the possibility of abnormalities in the process of auditory trace formation and temporal summation in schizophrenia.

Acoustic Stimulation↗
PubMed2000

Syndromic treatment of sexually transmitted diseases reduces the proportion of incident HIV infections attributable to these diseases in rural Tanzania.

OBJECTIVES: To compare the proportion of HIV seroconversions attributable to other sexually transmitted diseases in the intervention and comparison arms of the Mwanza sexually transmitted diseases (STD) intervention trial. DESIGN: Case-control study of 96 cases of HIV seroconversion and 974 HIV-negative controls, nested within the Mwanza trial cohort. METHODS: Data on reported STD symptoms during 2 years of follow-up, and serological evidence of recent syphilis, were used to obtain odds ratios (ORs) for HIV seroconversion, adjusted for community, age, marital status, sex partners and travel. Population-attributable fractions (PAF) of HIV seroconversions associated with these STD exposures were calculated separately for the intervention and comparison arms, and for men and women. RESULTS: In men in the comparison arm, adjusted ORs for ulcers (14.8), discharge (3.3), any symptom (4.1) and any STD (4.0) were highly significant. There were no significant associations between HIV incidence and STD exposures in the intervention arm. The PAF were consistently higher in the comparison arm than the intervention arm. In men, the PAF for any STD was 39.6% [95% confidence interval (CI), 12.4-58.3)] in the comparison arm but only 12.0% (CI, 0.0-35.9) in the intervention arm. The PAF for women were lower than for men. CONCLUSIONS: These are minimal PAF estimates and they do not account for STD effects on HIV infectiousness. Nevertheless, a substantial proportion of new HIV infections in men in the comparison arm were attributable to STD. Lower PAF in the intervention arm than in the comparison arm for men provide further evidence of the role of STD cofactors in HIV transmission, supporting the hypothesis that the Mwanza intervention reduced the duration of symptomatic STD, thus reducing the HIV risk associated with such STD.

Adolescent↗