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Biomedical subjects

N Baker

Publications and source records attributed to N Baker.

At least 19 recordsLinked to original sources
PubMed2002

Eikenella corrodens infective endocarditis in a previously healthy non-drug user.

Reported here is a case of Eikenella corrodens aortic valve infective endocarditis presenting as a stroke in a previously healthy 31-year-old man. The patient had no evidence of structural heart disease and reported no history of intravenous drug use or recent dental treatment. There are no other cases reported in the available literature in which this microorganism has caused endocarditis in the absence of recognised risk factors.

Adult↗
PubMed2002

The osteodystrophy of mucolipidosis type III and the effects of intravenous pamidronate treatment.

Mucolipidosis type III (ML III; McKusick 252600) is a rare lysosomal storage disease in which skeletal involvement is prominent, in particular the destruction of vertebral bodies and the femoral heads. We describe studies in two siblings with ML III that suggest the presence of a distinct metabolic bone disorder. Biochemical indices of bone turnover were increased, and transiliac bone biopsy demonstrated both trabecular osteopenia and marked subperiosteal bone resorption. Intravenous pamidronate treatment given monthly for a year was well tolerated and produced dramatic clinical effects, with reduction in bone pain and improvements in mobility, despite incomplete suppression of bone resorption as assessed by biochemical, radiographic and histological criteria. Bisphosphonate therapy may have an important role in the management of bone pain in ML III, as it does in the related lysosomal disorder of Gaucher disease.

Absorptiometry, Photon↗
PubMed2002

Socio-demographic and health system factors in relation to exclusive breast-feeding in Tobago.

To determine the prevalence and significant correlates of exclusive breast-feeding among nursing mothers, we conducted a survey among nursing mothers attending the Wellness Baby Clinic in Tobago from July 1 to December 1, 1998. A random sample of 151 mothers had face-to-face interviews with a standardized pretested questionnaire. Our results suggest that 48.3% and 20.8% of infants were exclusively breast-fed at two and four months respectively. Univariate logistic regression analyses showed that exclusive breast-feeding at two months was significantly positively associated with years of schooling completed by the mother, frequency of prenatal visits, mode of breast-feeding, mother's knowledge of the recommended duration of breast-feeding, and occupation of the child's father. Exclusive breast-feeding at four months was significantly positively associated with mother's age, years of schooling completed by the mother, frequency of prenatal visits, mother's knowledge of the recommended duration of breast-feeding, years of schooling completed by the child's father and occupation of the child's father. In multivariate logistic analyses, adjusting simultaneously for all relevant explanatory variables, exclusive breast-feeding at two months was significantly positively associated with frequency of prenatal clinic visits, mode of breast-feeding, mother's knowledge of the recommended duration of breast-feeding and occupation of the child's father. In addition, exclusive breast-feeding at four months was significantly positively associated with frequency of prenatal clinic visits, length of hospital stay, mother's knowledge of recommended duration of breast-feeding, years of schooling completed by the child's father, family structure and inversely associated with mother's age. In this sample, parental socio-demographic characteristics and health system factors were associated with subsequent infant feeding practices.

Adult↗
PubMed2001

An open-label trial of tomoxetine in pediatric attention deficit hyperactivity disorder.

OBJECTIVE: To collect pilot data assessing the safety, tolerability, and efficacy of tomoxetine, a nonstimulant norepinephrine enhancer, in pediatric attention deficit hyperactivity disorder (ADHD). METHODS: An open-label trial of tomoxetine in pediatric ADHD was conducted as part of a multisite clinical trial. Following a baseline assessment, an ascending dose titration was completed during 10 weekly visits. RESULTS: Ten subjects were enrolled at baseline, with eight completing the study. Seven of the eight remaining subjects met efficacy criteria. Significant decreases in symptom severity ratings by parents and study investigators were found. The medication was well tolerated, with transient appetite suppression the most frequently reported side effect. However, subjects' weights remained stable across study visits. DISCUSSION: These preliminary findings suggest that tomoxetine may hold promise as a treatment for pediatric ADHD.

Adolescent↗
PubMed2001

Dimensional perspective on the recognition of depressive symptoms in primary care: The Hampshire Depression Project 3.

BACKGROUND: Most studies of the recognition of depression in primary care have used a categorical definition of depression. This may overstate the extent of the problem. AIMS: Our objective was to investigate the relationship between severity and recognition of depression, and its modification by patient and practitioner characteristics. METHOD: An association study in multiple consecutive adult cohorts of 18 414 primary care consultations drawn from a representative sample of 156 general practitioners in Hampshire, UK. RESULTS: There was a curvilinear relationship between the severity of depression and practitioners' ratings of depression. One case of probable depression was missed in every 28.6 consultations. Anxiety and unemployment altered the chances of recognition, but age, gender and deprivation scores did not. CONCLUSIONS: A dimensional approach to severity of depression shows that general practitioners may be better able to recognise depression than previous categorical studies have suggested. Efforts to improve the care of depression should therefore focus on doctors who have been shown to have difficulty making the diagnosis and on improving the treatment of identified patients.

Adolescent↗
PubMed2001

Exploring the use of an alginate dressing for diabetic foot ulcers.

Few studies have investigated the use of dressings on patients with diabetic foot ulceration. This paper reports the results of a non-comparative, two-centre study investigating the performance characteristics of SeaSorb dressing in patients with this condition. This was an exploratory study to determine the potential use of this dressing, and not a large randomised control trial. All patients had diabetic foot ulceration of 1 cm or more in diameter, classified as Wagner grade I or II, with an ankle brachial pressure index of > 0.4. The investigators carried out objective assessments including photography and ulcer tracing as well as subjective assessments of exudate levels, wound bed condition, peri-ulcer skin condition, ease of application and removal of the dressing, dressing conformability, discomfort during dressing application and removal, and clinical signs of infection. Investigators recruited 41 patients in two sites (31 in site one and 10 in site two). Of these, the findings relating to 39 patients could be evaluated. The patients were treated for a maximum of six weeks or until the ulcer healed. The study found that 28.2% (11/39) of the ulcers healed within the six-week period. Overall, there was a significant reduction in mean ulcer area from 2.8 cm 2 to 1.02 cm 2 from week 0 to week six. The relative ulcer area showed a significant decrease from 100% to 33%. For patients who experienced ulcer pain (11 patients), its intensity decreased over the six weeks. Severe maceration was not reported for any patient throughout the study. Six patients required treatment for infection. A total of 12 adverse events were reported: seven mild to moderate and five severe. None were directly attributed to the study dressing.

Adult↗
PubMed2000

A look to the past, directions for the future.

This article represents the history of primary care and behavioral health integration at Group Health Cooperative (GHC) over the last decade, and foreshadows probable futures for this work into the next decade. To build from a logical progression, the article responds to a series of questions: 1. Why integrate primary care and behavioral health? 2. What has been done so far and how well has it worked? 3. Keeping the end in mind, what's the idealized picture of integration for the future? 4. How to get from here to there? What will help or hinder the effort? and 5. Again, why make these efforts to integrate?

Behavioral Medicine↗
PubMed2000

Council tax valuation band as marker of deprivation and of general practice workload.

This study tests the hypothesis that Council Tax Valuation Banding (CTVB) is a measure both of UK socioeconomic status and of general practice workload. It is a retrospective cohort study based in a UK semi-rural general practice, North Wiltshire. The study group is a randomised selection of UK general practice patients. The outcome measures are socio-demographic and primary care workload parameters versus CTVBs by logistic regression analyses in a sample of 378 patients (90% participation rate). People who pay little or no council tax are significantly less likely to live in owner-occupied homes or to have access to a car than their counterparts. There is also a significant inverse association between CTVB and demand for general practitioner services. CTVB could be an accessible, universal, non-census marker of UK socioeconomic status and of general practice workload that would have validity in the context of primary care resource allocation and is a concept worthy of further investigation.

Cohort Studies↗
PubMed1999

Fasting hyperinsulinemia and increased waist-to-hip ratios in non-wasting individuals with AIDS.

OBJECTIVE: To identify metabolic and body composition changes associated with HIV-1 infection in a cross-sectional study of individuals stratified by immunologic status and body mass. DESIGN: Metabolic abnormalities including glucose intolerance and changes in body morphology have recently been described in HIV-1-infected individuals following therapy with protease inhibitor-containing highly active anti-retroviral therapy. Although this is suggestive of a direct drug effect, the possibility that HIV infection may induce a tendency towards such underlying derangements should be considered. HIV-infected patients are heterogeneous with respect to immunologic status and body mass. In examining the underlying effect of HIV-1 on metabolic and body composition parameters, stratification by various immunologic and body mass categories may give divergent results that would not be detected otherwise. METHODS: Thirty male participants were categorized into four cohorts: non-wasting HIV-seronegative controls, non-wasting HIV-infected patients with relatively intact immune function (CD4 cell count > 500 x 10(6)/l); non-wasting individuals with AIDS (CD4 cell count < 200 x 10(6)/l); and individuals with AIDS wasting. RESULTS: Increased fasting plasma insulin and waist-to-hip ratios were found specifically in non-wasting individuals with AIDS compared with HIV-negative controls. CONCLUSIONS: Our study emphasises the importance of both body mass and immune function in studying metabolic and body composition abnormalities associated with HIV-1 infection. The association of increased waist-to-hip ratios and hyperinsulinemia suggestive of insulin resistance in non-wasting individuals with AIDS suggest that the tendency towards these metabolic abnormalities may be related to the HIV infectious process or to factors associated with immunologic dysfunction.

Anthropometry↗
PubMed1999

Theoretical and experimental investigations of electrostatic effects on acetylcholinesterase catalysis and inhibition.

The role of electrostatics in the function of acetylcholinesterase (AChE) has been investigated by both theoretical and experimental approaches. Second-order rate constants (kE = k(cat)/Km) for acetylthiocholine (ATCh) turnover have been measured as a function of ionic strength of the reaction medium for wild-type and mutant AChEs. Also, binding and dissociation rate constants have been measured as a function of ionic strength for the respective charged and neutral transition state analog inhibitors m-(N,N,N-trimethylammonio)trifluoroacetophenone (TMTFA) and m-(t-butyl)trifluoroacetophenone (TBTFA). Linear free-energy correlations between catalytic rate constants and inhibition constants indicate that kE for ATCh turnover is rate limited by terminal binding events. Comparison of binding rate constants for TMTFA and TBTFA attests to the sizable electrostatic discrimination of AChE. Free energy profiles for cationic ligand release from the active sites of wild-type and mutant AChEs have been calculated via a model that utilizes the structure of T. californica AChE, a spherical ligand, and energy terms that account for electrostatic and van der Waals interactions and chemical potential. These calculations indicate that EA and EI complexes are not bound with respect to electrostatic interactions, which obviates the need for a 'back door' for cationic ligand release. Moreover, the computed energy barriers for ligand release give linear free-energy correlations with log(kE) for substrate turnover, which supports the general correctness of the computational model.

Acetophenones↗
PubMed1999

Elevated glutathione biosynthetic capacity in the chloroplasts of transgenic tobacco plants paradoxically causes increased oxidative stress

Glutathione (GSH), a major antioxidant in most aerobic organisms, is perceived to be particularly important in plant chloroplasts because it helps to protect the photosynthetic apparatus from oxidative damage. In transgenic tobacco plants overexpressing a chloroplast-targeted gamma-glutamylcysteine synthetase (gamma-ECS), foliar levels of GSH were raised threefold. Paradoxically, increased GSH biosynthetic capacity in the chloroplast resulted in greatly enhanced oxidative stress, which was manifested as light intensity-dependent chlorosis or necrosis. This phenotype was associated with foliar pools of both GSH and gamma-glutamylcysteine (the immediate precursor to GSH) being in a more oxidized state. Further manipulations of both the content and redox state of the foliar thiol pools were achieved using hybrid transgenic plants with enhanced glutathione synthetase or glutathione reductase activity in addition to elevated levels of gamma-ECS. Given the results of these experiments, we suggest that gamma-ECS-transformed plants suffered continuous oxidative damage caused by a failure of the redox-sensing process in the chloroplast.

Journal Article↗
PubMed1998

Symptom control in patients with hay fever in UK general practice: how well are we doing and is there a need for allergen immunotherapy?

BACKGROUND: Seasonal allergic rhinitis is often regarded as a trivial condition which patients should treat themselves. However, a significant proportion of sufferers are not fully controlled on standard hay fever medication, either because they do not use it properly or because their symptoms are resistant to standard therapy. The latter group may be suitable for allergen immunotherapy, which was once widely available in UK general practice but is now only available through specialist centres. AIMS: To describe the symptom control of patients with hay fever, to assess concordance with prescribed medication, and to estimate the number of patients who may benefit from referral for allergen immunotherapy. SETTING: General practices in Hampshire and Dorset, UK. METHOD: Survey of adult hay fever sufferers prescribed a non-sedating antihistamine and nasal steroid spray by their general practitioner. A postal questionnaire was sent to all eligible patients aged 16-64 registered with 16 general practices. Self-assessment of symptom control and reported compliance with medication were used to identify those patients who were suboptimally controlled and might therefore benefit from immunotherapy. RESULTS: Eight hundred and forty-six out of 62500 registered patients aged 16-64 (1.4%) were receiving both drugs, and responses were received from 627 (74.1%); 526 of these met the full entry criteria. One hundred and forty-two patients (27.0%) were using both types of drug regularly. Of the 142 patients using optimum pharmacotherapy, 54 (38.0%) reported good control of their hay fever symptoms. The remaining 62.0% experienced troublesome residual symptoms and described symptom control as partial or poor. Among those using suboptimal pharmacotherapy, 181/376 (48.1%) reported good control. CONCLUSION: Many patients are using treatment inappropriately. Current guidelines need to be applied better but there is also a significant burden of residual symptoms, even among those receiving current optimal therapy. This indicates a need for patients with severe summer hay fever to receive specialist assessment.

Adolescent↗
PubMed1998

The role of the insulin-like growth factor system in the developing brain.

Insulin-like growth factors (IGFs) play a central role in brain growth and development, with IGF-1, its receptors and binding proteins (IGFBPs) being highly expressed, particularly in the olfactory bulb (OB), representing a local paracrine system. A potential role of IGFBPs in transporting and targeting IGFs to their receptors is supported by the finding that abundant IGFBP-2 is associated with cell surface proteoglycans. An OB organ culture system expressing IGF-1 and IGFBPs represents an in vitro injury model. Although IGF-1 is potently antiapoptotic for neurons and oligodendrocytes, marked gliosis and IGFBP-3 expression are seen, similar to in vivo injury responses, where intraventricular injection of IGF-1 postinjury enhances neuronal survival by blocking apoptosis. In contrast, des (1-3) IGF-1, which has low affinity for IGFBPs, is ineffective, supporting a transport or receptor targeting role for local IGFBPs. We conclude that the IGF system plays a crucial cell survival and growth role in the developing and injured brain and that IGFs have significant therapeutic potential.

Animals↗