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Biomedical subjects

H Baker

Publications and source records attributed to H Baker.

At least 19 recordsLinked to original sources

Cyclin D1 protein expression in human thyroid gland and thyroid cancer.

Cell cycle progression is facilitated by cyclin dependent kinases (CDKs) that are activated by cyclins, including Cyclin D1 and inhibited by CDK inhibitors. Evidence of the involvement of cyclin gene alterations and over expression of various cyclins in human cancer is growing. The role of Cyclin D1 in malignant progression of papillary carcinomas of the thyroid has yet to be established. We therefore studied the expression of Cyclin D1 protein in thyroid carcinomas of young Kuwaiti patients (36 cases of conventional papillary thyroid carcinoma, 12 cases of its follicular variant, one case of tall cell thyroid carcinoma and one case of medullary carcinoma) using immunohistochemistry. In 23 patients (46%) circumscribed areas of cells were detected that showed a distinct to strong nuclear staining for immunoreactive Cyclin D1 whereas the remaining bulk of the carcinoma cells were negative or only showed a slight cytoplasmic staining. None of the tested clinical or path histological parameters showed a statistically significant correlation with the focal immunostaining. This does not rule out that the detected foci with positive nuclear Cyclin D1 immunostaining are areas where a progressive transformation to a more malignant phenotype occurs which eventually leading to lymph node and distant metastases.

Adenocarcinoma, Follicular↗

Evaluation of a required statewide interdisciplinary Rural Health Education Program: student attitudes, career intents and perceived quality.

INTRODUCTION: A shortage of healthcare providers in West Virginia led to creation of a statewide, community-based program with a required three-month rural experience for most state-sponsored health professions students. Project Description: Initiated using funding from the W. K. Kellogg Foundation and expanded using both state funds and Area Health Education Center support, the West Virginia Rural Health Education Partnerships (WVRHEP) program impacts institutions of higher learning, 50 counties, and 332 training sites, and all students in state-funded health professions schools. A longitudinal database has been constructed to study program effects on students' reported attitudes, service orientation, and career intents. METHODS: Baseline data are collected from medical students, and students in all disciplines provide feedback on rotations and information about career intents, social responsibility, and attitudes towards rural practice. RESULTS: Data indicate an association between perceived quality of the rural experience and increased interest in rural health, social responsibility and confidence in becoming part of the community. Medical students may tend to rate social responsibility higher after completion of the first rural rotation. Students who anticipate practice in smaller towns also tend to rate the quality of the rotation higher, to anticipate careers in primary care, and to acknowledge social responsibility. CONCLUSION: As WVRHEP program graduates who have completed these surveys enter practice, both personal and community-specific program characteristics may be identified which strengthen interest in rural practice. The predictive validity of intermediate outcomes of attitudes and career intents in forecasting the ultimate outcomes of recruitment and retention may be studied.

Attitude↗

UK population based study of severe retinopathy of prematurity: screening, treatment, and outcome.

BACKGROUND: Retinopathy of prematurity (ROP) is one of the few causes of childhood blindness in which severe vision impairment is largely preventable. Ophthalmic screening for ROP is required to identify disease that requires treatment whereby the development of potentially blinding disease can be minimised. OBJECTIVES: To make the first UK population based estimate of the incidence of babies with severe ROP (stage 3 or more); to document their clinical characteristics and management and to evaluate the appropriateness of current ROP screening guidelines in the UK. PATIENTS: Cases were recruited through a national surveillance programme with 1 year ophthalmic follow up and data from clinician completed questionnaires. RESULTS: Between 1 December 1997 and 31 March 1999, 233 preterm babies with stage 3 ROP were identified. Severity (location, extent, and presence of plus disease) was associated with degree of prematurity, most severe in the most premature babies. Fifty nine percent were treated. The UK screening protocol was followed in two thirds of cases, but in the remainder it was begun too late or was too infrequent. Three quarters of the cases were followed up at 1 year, and 13% had a severe vision deficit as a result of ROP. CONCLUSIONS: Visual deficit as a result of ROP in premature babies continues to be a severe disability in some of the survivors of neonatal intensive care. Further efforts are needed to organise treatment regionally to improve outcome and standards of practice.

Birth Weight↗

Differential regulation of laminin b1 transgene expression in the neonatal and adult mouse brain.

Laminins are the major glycoproteins present in basement membrane, a type of extracellular matrix. We showed that the LAMB1 gene, which encodes the laminin beta1 subunit, is transcriptionally activated by retinoic acid in embryonic stem cells. However, little information is available concerning LAMB1 developmental regulation and spatial expression in the adult mouse brain. In this study we used transgenic mice expressing different lengths of LAMB1 promoter driving beta-galactosidase to investigate developmental and adult transcriptional regulation in the regions of the brain in which the laminin beta1 protein is expressed. CNS expression was not observed in transgenic mice carrying a 1.4LAMB1betagal construct. Mice carrying a 2.5LAMB1betagal construct expressed the LAMB1 transgene, as assayed by X-gal staining, only in the molecular layer of the neonatal cerebellum. In contrast, a 3.9LAMB1betagal transgene showed broad regional expression in the adult mouse brain, including the hippocampus, entorhinal cortex, colliculi, striatum, and substantia nigra. Similar expression patterns were observed for the endogenous laminin beta1 protein and for the 3.9LAMB1betagal transgene, analyzed with an antibody against the beta-galactosidase protein. The 3.9LAMB1betagal transgene expression in the hippocampal tri-synaptic circuit suggests a role for the LAMB1 gene in learning and memory.

Animals↗

Can a public health package on glaucoma reach its target population?

PURPOSE: A pilot study to assess how successful a newspaper advertisement and a radio interview about glaucoma are at reaching their target population. METHODS: The health intervention comprised two components: an interview on local radio and an advertisement in the local paper. Our target population were residents aged 45 years and above in either Southall (West London) or the Isle of Wight (IOW). A questionnaire was developed to be carried out pre- and post-intervention. The data from both locations pre and post were coded and cleaned. Tests of significance were carried out to assess statistical significance for differences in proportion, with tests for trend used where appropriate. All statistical analyses were carried out using Stata7. RESULTS: Overall, the proportion who had heard of glaucoma increased from 54% before the intervention to 60% after (chi(2) = 3.7, P = 0.055). The proportion who had heard of the disease increased by 13% (chi(2) = 8.76, P = 0.003) in Southall and by 8% (chi(2) = 5.02, P = 0.025) on the IOW. The proportion reporting seeing the advert increased significantly in both areas with greater effect in Southall. Those reporting hearing the radio interview only increased in Southall. On the IOW, females were more knowledgeable and responded more positively to the intervention. This differed in Southall where males tended to be the positive responders. Conclusion In both areas a significant effect on those having heard of glaucoma was found. This could be attributed to both the advert and interview in Southall but would appear to be attributable to the newspaper advertisement alone on the IOW.

Advertising↗

Steatosis and fibrosis in patients with chronic hepatitis C.

BACKGROUND: Steatosis is present on liver biopsy in approximately 50% of patients with hepatitis C; its association with stage of fibrosis has been reported, but its relation to other fibrosis associated factors is unknown. AIM: To study the relation between steatosis and other histological features in patients with hepatitis C, and changes in steatosis with time. METHODS: Cross sectional study: 233 routine liver biopsies from 219 patients with hepatitis C; hepatectomy specimens from 65 patients transplanted for hepatitis C cirrhosis. Longitudinal study: 41 patients with two biopsies and 10 patients with three biopsies performed over 2-8 years. Biopsies were scored by the Ishak scheme, and degree of steatosis assessed subjectively. Multivariate analysis was used to study the interaction of fibrosis associated factors. Changes in steatosis over time in individual patients were explored in the longitudinal study. RESULTS: Steatosis was present in 50% of biopsies. It correlated strongly with fibrosis in non-cirrhotic samples, but declined in cirrhosis, and was unusual in transplant hepatectomy specimens. On multivariate analysis of non-cirrhotic biopsies, steatosis was associated with increasing patient age and remained significantly associated with fibrosis independent of portal inflammation and interface hepatitis. In the longitudinal study, steatosis persisted and increased over time, except in patients developing cirrhosis. CONCLUSIONS: Steatosis is associated with fibrosis independently of necroinflammation, but declines in cirrhosis. It may represent a pathogenic pathway distinct from necroinflammatory activity in the generation of liver fibrosis, and should be included in the assessment of biopsies for clinical and research purposes.

Adolescent↗

Clinicopathological features of extranodal lymphomas: Kuwait experience.

A total of 935 patients with extranodal non-Hodgkin lymphoma (NHL) diagnosed in the period between January 1985 and December 2000 in Kuwait Cancer Center, serving the whole population of Kuwait, were used to describe the clinicopathological and epidemiological features of extranodal lymphomas in Kuwait. Extranodal lymphomas accounted for 45% of all NHL observed during this time. All NHL cases from Kuwait Cancer registry were analyzed and pathologically reclassified using the latest WHO (2000) classification. The most common lymphoma observed was diffuse large B-cell lymphoma (58.60%) followed by Burkitt s lymphoma (BL) (3.80%). In the pediatric group, BL comprises more than two thirds of all patients (77.20%). The most common extranodal sites were stomach (19.70%) and skin (17.80%) in the adult group, large intestine (29.80%) and small intestine (19.30%) in the pediatric age group. The majority (73.40%) of adult extranodal lymphomas was in stage IE-IIE and had a very good prognosis. On the contrary, the majority of pediatric extranodal lymphomas were found to be in stage III and IV. Variations in treatment policies (single agent or combined chemotherapy, radiotherapy, combined modality treatment) adopted and changed during the time period of 16 years of this retrospective study were documented.

Adolescent↗

Community mental health nurses and authority to prescribe medications: the way forward?

This paper explores a single dimension of the nurse practitioner role - whether community mental health nurse practitioners should have authority to prescribe medications. The paper is taken from a larger study about how these nurses promote wellness with clients experiencing an early episode of psychotic illness. The focus is timely as several Australian States have recently passed nurse practitioner legislation. This qualitative study used interviews and participant observation to collect data. The fieldwork was undertaken in the community, in regional and rural New South Wales, Australia and involved community mental health nurses. The findings show that expanding the nurse practitioner role to include authority to prescribe medications is currently contentious. Respondents envisaged that prescribing authority would include most medications that are used to treat mental illness but exclude drugs that treat medical illness. They identified a need for an appropriate educational course, and called for a system of clinical supervision and ongoing support for nurses assuming this role. Participants also claimed that individual nurses who choose to forgo prescribing authority should not be coerced into undertaking this role. The findings have professional, clinical, legal and educational implications for nurses as they seek authority to prescribe within the context of a nurse practitioner role and these are discussed.

Community Mental Health Services↗

Phenotypic differentiation during migration of dopaminergic progenitor cells to the olfactory bulb.

A possible source for transplantable neurons in Parkinson's disease are adult olfactory bulb (OB) dopamine (DA) progenitors that originate in the anterior subventricular zone and reach the OB through the rostral migratory stream. We used adult transgenic mice expressing a lacZ reporter directed by an 8.9 kb tyrosine hydroxylase (TH) promoter to investigate the course of DAergic differentiation. Parallel transgene and intrinsic TH mRNA expression occurred during migration of DA interneurons through the mitral and superficial granule cell layers before these cells reached their final periglomerular position. Differential transgene and calcium-calmodulin-dependent protein kinase IV expression distinguished two nonoverlapping populations of interneurons. Transgenic mice carrying a TH8.9kb/lacZ construct with a mutant AP-1 site demonstrated that this element confers OB DA-specific TH gene regulation. These results indicate that DA phenotypic determination is specific to a subset of mobile OB progenitors.

Animals↗

National Cancer Institute initiative: Lung image database resource for imaging research.

Preliminary clinical studies suggest that spiral computed tomography (CT) of the lungs can improve early detection of lung cancer in high-risk individuals. More clinical studies are needed, however, before public health recommendations can be proposed for population-based screening. Spiral CT generates large-volume data sets and thus poses problems in terms of implementation of efficient and cost-effective screening methods. Image processing algorithms such as computer assisted diagnostic (CAD) methods have the potential to assist in lesion (eg, nodule) detection on spiral CT studies. CAD methods may also be used to characterize nodules by either assessing the stability or change in size of lesions based on evaluation of serial CT studies, or quantitatively measuring the temporal parameters related to contrast dynamics when using contrast material-enhanced CT studies. CAD methods therefore have the potential to enhance the sensitivity and specificity of spiral CT lung screening studies. Lung cancer screening studies now under investigation create an opportunity to develop an image database that will allow comparison and optimization of CAD algorithms. This database could serve as an important national resource for the academic and industrial research community that is currently involved in the development of CAD methods. The National Cancer Institute request for applications (RFA) (CA-01-001) has already been announced (April 2000) to establish and support a consortium of academic centers to develop this database, the consortium to be referred to as the Lung Image Database Consortium (LIDC). This RFA is now closed. Five academic sites have been selected to be members of the LIDC, the first meeting of this consortium is planned for spring of 2001, and a public meeting is to be held in 2002. This report is abstracted from the previously published RFA to serve as an example of how an initiative is developed by the National Cancer Institute to support a research resource. For specific details of the RFA, please access the following Internet site: http://www. nci.nih.gov/bip/NCI-DIPinisumm.htm#a11.

Algorithms↗

NCI image archive management workshop: a preliminary report.

The National Cancer Institute organized a workshop entitled "Image Archive Management" that was presented on August 28 and 29, 2000, at the Natcher Conference Center on the National Institutes of Health (NIH) campus. The purpose of this workshop was to solicit expert input for the planned development of an archival system to make imaging databases readily accessible by the broad scientific community. The specific goals were to (a) define the technical requirements for a virtual archive of images used in oncology, (b) define the policy issues for access to these images, (c) recommend a process and phases for implementation of a robust imaging archival system, (d) review how this effort could be expanded and coupled with other ongoing efforts by NIH and other organizations interested in imaging, and (e) form an overall plan and policy to allow interoperability of image data archives. Representatives who attended the workshop came from academia, government agencies, and large and small businesses. A preliminary report was generated, as outlined herein, and additional reports are anticipated from the steering committee being organized as one of this workshop's recommendations, which is expected to be active by summer 2001. Additional information, including the list of participants in this workshop, is available at the Biomedical Imaging Program Web site (http://www.nci.nih.gov/bip/).

Humans↗

Mutual relating: developing interpersonal relationships in the community.

AIM OF THE PAPER: This paper, which is part of a larger study that examined how community mental health nurses promoted wellness with young adult who were experiencing an early episode of psychotic illness, aims to explicate how nurses develop interpersonal relationships with these consumers. RATIONALE: Research into the development of interpersonal skills is important because they are an essential foundation to the promotion of wellness in psychotic illness. DESIGN/METHODS: The study used Strauss and Corbin's approach to grounded theory methodology. Concurrent data collection and analysis was undertaken incorporating interviews and observations. The study took place in the community, in rural and regional New South Wales, Australia, and involved consumers, significant others, and community mental health nurses. RESULTS: The findings show that several strategies are associated with mutual relating. Attempting to understand necessitates nurses trying to see it from insiders' points of view, while acknowledging that they can never completely understand their illness experience. Being friendly indicates that the qualities of a friendly relationship should be implicit in a professional friendship. Tuning in involves taking account of and adjusting to consumers' ways of dressing, communicating, and the types of approaches that consumers prefer. Revealing oneself is a process that helps put both consumers and nurses at ease, and helps dispel the perception consumers take part in a one-sided relationship. Being there for them, is a particular type of obligation that entails nurses being accountable for the care they provide, being a spokesperson for consumers, if required, and avoiding collusion with others. Related to avoiding collusion, is the issue of maintaining confidentiality, particularly within the context of interacting with significant others. CONCLUSION: The results of the study have implications for the way nurses develop and maintain interpersonal relationships with consumers, and this is affected by nurses' personal and professional attributes.

Adaptation, Psychological↗

Contemporary nurses' uniforms---history and traditions.

This paper explores the literature related to the history and traditions of contemporary nurses' uniforms. It also presents the views of nurses about uniforms following the abandonment of a prescribed uniform for nurses working in a Professorial Nursing Unit in a large Hospital in Victoria. The literature dealing with the question of uniforms focuses on professionalism, status and power, infection control, identity, modesty, symbolism and occupational health and safety. The nurses who participated in the study expressed many of these themes.

Attitude of Health Personnel↗

Re-evaluation of the metabolism of oral doses of racemic carbon-6 isomers of formyltetrahydrofolate in human subjects.

The racemic mixture, [6RS]-5-formyltetrahydrofolate, is widely used clinically. In human subjects, orally-administered pure unnatural C-6 isomers, [6R]-5-formyltetrahydrofolate and [6S]-5,10-methenyltetrahydrofolate, were recently shown to be metabolized to the natural isomer, [6S]-5-methyltetrahydrofolate. We re-analysed the data from human studies published during the past four decades in which oral doses (< or =10 mg) of racemic mixtures of these folates were used. We re-evaluated the data to determine whether these racemic mixtures are only 50 % bioactive or, as we now predict, more than 50 % bioactive. Our analyses indicate that, in human subjects, oral doses of the racemic mixture of the two formyltetrahydrofolates are 20-84 % more bioactive than would be predicted. These data are consistent with the following pathway: chemical conversion of these folates to 10-formyltetrahydrofolate; oxidation of 10-formyltetrahydrofolate to 10-formyldihydrofolate; subsequent enzymic conversion of 10-formyldihydrofolate to dihydrofolate by 5-amino-4-imidazolecarboxamide ribotide transformylase; and finally the well-established metabolism of dihydrofolate to [6S]-5-methyltetrahydrofolate. An additional review of the literature supports the in vivo oxidation of 10-formyltetrahydrofolate occurring to a certain extent, as 10-formyl-folic acid is rapidly formed after the administration of folic acid (pteroylglutamic acid) or 5-formyltetrahydrofolate in human subjects. The dogma that an oral dose of the unnatural C-6 isomer of 5-formyltetrahydrofolate is not bioactive in human subjects does not withstand scrutiny, most probably due to the previously unrecognized in vivo oxidation of 10-formyltetrahydrofolate. This discovery unveils new folate metabolism in human subjects.

Administration, Oral↗

Women's experience of IVF: a follow-up study.

The aim of this research was to increase understanding of how women feel about the experience of IVF 2-3 years after ceasing treatment. A questionnaire covering issues relating to infertility and the value of the experience of IVF together with three self-report measures [Satisfaction With Life Scale (SWLS), Golombok Rust Inventory of Marital State (GRIMS) and General Health Questionnaire (GHQ-12)] were mailed to all women (n = 229) who had their last contact with the clinic in 1994. The response rate was 55%. Having a baby positively influenced the recall of the IVF experience. Women who did not have a baby were more critical about the clinic and more negative about the experience of treatment but did not regret having tried IVF. These women had statistically significantly lower scores on SWLS but did not differ from those with babies on GRIMS and GHQ-12 scales. The results give insight into how women look back on the IVF experience and what aspects of treatment they recall as particularly difficult. The findings can be used by providers of IVF to implement strategies that may reduce stress and improve the patients' well-being.

Adult↗

Vestibuloocular reflex of the adult flatfish. III. A species-specific reciprocal pattern of excitation and inhibition.

In juvenile flatfish the vestibuloocular reflex (VOR) circuitry that underlies compensatory eye movements adapts to a 90 degrees relative displacement of vestibular and oculomotor reference frames during metamorphosis. VOR pathways are rearranged to allow horizontal canal-activated second-order vestibular neurons in adult flatfish to control extraocular motoneurons innervating vertical eye muscles. This study describes the anatomy and physiology of identified flatfish-specific excitatory and inhibitory vestibular pathways. In antidromically identified oculomotor and trochlear motoneurons, excitatory postsynaptic potentials (EPSPs) were elicited after electrical stimulation of the horizontal canal nerve expected to provide excitatory input. Electrotonic depolarizations (0.8-0.9 ms) preceded small amplitude (<0.5 mV) chemical EPSPs at 1.2-1.6 ms with much larger EPSPs (>1 mV) recorded around 2.5 ms. Stimulation of the opposite horizontal canal nerve produced inhibitory postsynaptic potentials (IPSPs) at a disynaptic latency of 1.6-1.8 ms that were depolarizing at membrane resting potentials around -60 mV. Injection of chloride ions increased IPSP amplitude, and current-clamp analysis showed the IPSP equilibrium potential to be near the membrane resting potential. Repeated electrical stimulation of either the excitatory or inhibitory horizontal canal vestibular nerve greatly increased the amplitude of the respective synaptic responses. These observations suggest that the large terminal arborizations of each VOR neuron imposes an electrotonic load requiring multiple action potentials to maximize synaptic efficacy. GABA antibodies labeled axons in the medial longitudinal fasciculus (MLF) some of which were hypothesized to originate from horizontal canal-activated inhibitory vestibular neurons. GABAergic terminal arborizations were distributed largely on the somata and proximal dendrites of oculomotor and trochlear motoneurons. These findings suggest that the species-specific horizontal canal inhibitory pathway exhibits similar electrophysiological and synaptic transmitter profiles as the anterior and posterior canal inhibitory projections to oculomotor and trochlear motoneurons. Electron microscopy showed axosomatic and axodendritic synaptic endings containing spheroidal synaptic vesicles to establish chemical excitatory synaptic contacts characterized by asymmetrical pre/postsynaptic membrane specializations as well as gap junctional contacts consistent with electrotonic coupling. Another type of axosomatic synaptic ending contained pleiomorphic synaptic vesicles forming chemical, presumed inhibitory, synaptic contacts on motoneurons that never included gap junctions. Altogether these data provide electrophysiological, immunohistochemical, and ultrastructural evidence for reciprocal excitatory/inhibitory organization of the novel vestibulooculomotor projections in adult flatfish. The appearance of unique second-order vestibular neurons linking the horizontal canal to vertical oculomotor neurons suggests that reciprocal excitation and inhibition are a fundamental, developmentally linked trait of compensatory eye movement circuits in vertebrates.

Abducens Nerve↗

Implementing a community-based social marketing project to improve agricultural worker health.

The Together for Agricultural Safety project is a community-based social marketing project working to reduce the adverse health effects of pesticide exposure among fernery and nursery workers in Florida. In 3 years, the collaboration between university and community researchers has embodied many of the principles of community-based research while completing multiple stages of formative data collection required for a social marketing project. This hybrid approach to developing a health intervention for a minority community has been successful in its early stages because the community partners are organized, empowered, and motivated to execute research activities with the assistance of academic partners. However, this work has also been labor intensive and costly. This article describes the lessons learned by project partners and considers the limitations of this approach for agricultural health research.

Adult↗