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Biomedical subjects

A Worth

Publications and source records attributed to A Worth.

At least 19 recordsLinked to original sources
PubMed2006

Validation of counter propagation neural network models for predictive toxicology according to the OECD principles: a case study.

The OECD has proposed five principles for validation of QSAR models used for regulatory purposes. Here we present a case study investigating how these principles can be applied to models based on Kohonen and counter propagation neural networks. The study is based on a counter propagation network model that has been built using toxicity data in fish fathead minnow for 541 compounds. The study demonstrates that most, if not all, of the OECD criteria may be met when modeling using this neural network approach.

Animal Use Alternatives↗
PubMed2005

[Fitness of children--children's health].

Results of health studies on children and adolescents show clearly their physical and psychosocial impairments. Stress, social isolation, familial strains, false diet behaviour and above all a lack of activity play a major role as risk factors for the health of children. Closely connected to the last-named risk factor, lack of activity, is the physical performance or fitness of children and adolescents. The findings on physical performance of children and adolescents are still heterogeneous. This situation is primarily due to the difficulties in comparing the data because of the application of different test procedures as well as the different determinations of critical values for "noticeable problems" - thus a clear agreement about what test achievements are good or not good is hardly possible. Despite these methodological difficulties one can note that literature reviews from Bös, Dordel and Gaschler as well as different studies support the assumption that the physical performance of children and adolescents has decreased in the last two decades. From 1975 until 2000 the difference in ability amounts to about 10%, whereas the regression in ability can be seen the plainest in course endurance and flexibility, for both boys and girls. In fact physical performance and physical fitness are basic health resources. Through the fortification of the cardiovascular system, stabilisation of the retaining and motion apparatus and the economization of motion executions, physical fitness is an important protection against metabolic risks, psychosomatic disorders and diseases as well as accidents.

Adolescent↗
PubMed2004

Challenges in conducting research with hospitalized older people with cancer: drawing from the experience of an ongoing interview-based project.

Older people with cancer often face the prospect of cognitive and physical frailty, increased vulnerability of psychological distress and limited access to resources. These factors present ethical and methodological challenges for conducting research in such patients, especially interviews in acute care settings. This paper discusses these challenges using experiences from an ongoing research project. The project is a patient-focused study on the perceptions of older people with cancer regarding information provided to them, decision making and treatment. Interviews with patients aged 65 or over with a cancer diagnosis are conducted in two clinical settings, care of the elderly wards and a cancer centre whilst they are in-patients. Patients' cognitive and physical status are assessed using clinical measures, whereas socio-demographic and medical data are obtained from patient files. Ethical challenges, including procedures to obtain valid consent, as well as methodological choices, including recruitment procedures and patient conditions are presented and debated with reference to previous literature. Suggestions for future research with older people with cancer are made based both on current experience and previous literature.

Aged↗
PubMed2004

Migration of wooden skewer foreign bodies from the gastrointestinal tract in eight dogs.

Wooden skewer foreign bodies were found in eight dogs. Five presented for evaluation of draining sinuses and two for inflammatory disease referrable to the thorax, abdomen or pelvic region. In an additional case, pneumothorax resulted from perforation of the stomach and diaphragm. Ingestion was considered the most likely mode of access of the foreign body in all cases. Although the wooden foreign bodies were seen radiographically in only two dogs, identification of soft tissue or bony changes, or the results of contrast sinography assisted diagnosis. Surgical retrieval led to resolution of signs in all cases.

Abdomen↗
PubMed2002

[Examination of motor fitness within the scope of The Child and Adolescent Health Survey].

Several studies indicate that physical performance of children and young people is declining. However, actually available data on physical performance and physical activity of children and young people are not representative and hence no countrywide predictions can be made. The examination of motor fitness in association with development and health of children and young people is indispensable for the implementation of appropriate measures of intervention. The module 'Motoric' in the National Health Survey for Children and Adolescents shall remedy the deficiency of information. For the module, 6,000 children and adolescents, age 4-17 years, will be representatively drawn from the total survey sample. Their physical performance and physical activity will be comprehensively assessed. For this purpose, appropriate tests have been developed. In pilot studies, all methods were tested for practicability, objectivity, reliability, and validity. The application of methods was coordinated between the Robert Koch-Institute and the Institute of Sport and Science of Sports, University of Karlsruhe.

Adolescent↗
PubMed2001

Assessment of the needs of older people by district nurses and social workers: a changing culture?

This paper reports on a qualitative study which explored the process of assessment of the needs of older people by district nurses and social workers. In the UK, district nurses and social workers are two of the key practitioner groups responsible for assessing the health and social needs of older people in the community. Assessment of need is one of the core skills of community practitioners, with the potential to substantially affect a person's quality of life. An ethnographic approach was taken to analysing the assessment process in district nursing and social work, encompassing interviews with practitioners and observation of assessment practice. The similarities and differences between assessment of the needs of older people as conducted by district nurses and social workers are explored, with a view to identifying particular areas of expertise in this crucial area of practice. The study findings suggest that there are a number of similarities in the assessment practice of district nurses and social workers, but that the focus of their assessments differs in important respects. Organisational and educational differences and resource constraints were found to have a marked effect on producing differences in the process of assessment between the two groups.

Aged↗
PubMed2001

Proximal hypospadias. Comparative evaluation of staged urethroplasty (modified Thiersch Duplay followed by Mathieu) and single stage on-lay island flap repair.

OBJECTIVES: Comparative analysis of functional results, complications, cosmesis, operative time and hospital stay between staged urethroplasty and single-stage on-lay island flap for proximal hypospadias. MATERIALS AND METHODS: Non-randomised single observer study of two groups of patients over a 5-year period with proximal hypospadias. Group 1 had 17 patients (mean age 17.7+/-1.6 months) who underwent a staged urethroplasty. Urethral plate was tubularised and proximal hypospadias converted to a distal hypospadias. Hooded dorsal prepuce was buttonholed and transposed ventrally to cover the neo-urethra. Subsequently a parameatal based flip flap urethroplasty completed urethral reconstruction. Group 2 had 17 patients (mean age 18.2+/-2.2 months) with a single stage inner preputial on-lay island flap based on superficial dorsal vessels. RESULTS: Mean period of follow-up has been 2.8+/-1.7 years in group 1 vs. 3.2+/-1.6 years in group 2 (p = 0.2). In both groups (34), 79% of the children who are now toilet trained and standing to void have a good calibre straight single stream of urine in a forward direction (p = 1.00). Main complication seen in both groups was urethrocutaneous fistulae: 6% (1/17) in group 1 vs. 59% (10/17) in group 2 (p = 0.0002). In both groups (34) cosmetic appearance of a natural vertical slit glanular meatus situated at the normal position on the glans was achieved (p = 1.00). Total mean duration of operative time in group 1 was 193.5+/-42.9 vs. 203+/-27.6 min in group 2 (p = 0.24). Total mean duration of hospital stay in group 1 was 3.4+/-0.6 vs. 9.2+/-2.9 days in group 2 (p = 0.0001). Total mean cost of the procedure in group 1 was 2,347.3 pounds +/- 220 vs. 3,753.5 pounds +/- 75 in group 2 (p = 0.002). CONCLUSION: Staged urethroplasty for proximal hypospadias results in a normal penis with good function, minimal complications and excellent cosmesis. Hospital stay was shorter and overall cost lower than a single stage on-lay island flap urethroplasty.

Age Factors↗
PubMed2000

A qualitative evaluation of the effectiveness of health visiting practice.

The evaluation of health visiting interventions is a contentious issue and there is a need to develop methods of evaluation which move beyond organizationally-led targets. This article presents the findings of a study which explored the effectiveness of health visiting interventions from the perspectives of parents and health visitors. A qualitative approach was used which allowed the views of parents and health visitors to be examined within the context of their understanding of the parenting role. It is argued that this approach contributes to the evidence base of health visiting. Findings support the value of the health visitor-client relationship, formed mainly through home visiting, as the cornerstone of successful interventions. Parents in this study welcomed the health visitor's support in helping them to develop their parenting skills against a background of social change. At a time when the roles of health visitors are being renegotiated, the findings demonstrate the relevance of health visiting in contemporary society.

Attitude to Health↗
PubMed1999

Radial sclerosing lesions of the breast: mammographic and pathologic correlation.

OBJECTIVE: The purpose of this study was to define the mammographic appearance of 96 pathologically proven radial sclerosing lesions (RSLs) and to determine the frequency of association with malignancy in and around the lesions. METHODS: Ninety-three patients with 96 RSLs were identified from the pathology files of the BC Cancer Agency, and the reasons for biopsy were obtained. All preoperative mammograms were reviewed, and the RSLs were categorized as classic (typical), non-classic (atypical), or incidental. The histopathologic results were retrospectively examined for atypia, ductal carcinoma in situ (DCIS) and invasive carcinoma. RESULTS: In 67 of the 96 biopsies, the RSL was the primary mammographic abnormality that led to biopsy. In this group, 17 cases (25.4%) contained atypia, 17 (25.4%) DCIS, and 4 (6%) invasive carcinoma. Nineteen of these RSLs presented as mass-like opacities that mimicked carcinoma. No single mammographic feature consistently predicted premalignant or malignant lesions. In the remaining 29 patients, biopsy was carried out because of pleomorphic calcifications or masses, and RSLs were found incidentally in specimens. These specimens included 4 cases (13.8%) of atypia, and 1 case (3.4%) of DCIS. CONCLUSION: Of the 67 mammographically detected RSLs, only 48 (71.6%) had a typical mammographic appearance. We found a significant amount of atypia (25.4%) and malignancy (25.4% DCIS and 6% invasive carcinoma) in mammographically detected RSLs. Because of the lack of predictable radiological features, adequate open surgical biopsy is recommended for all focal abnormalities in which a RSL is a possible diagnosis.

Adult↗
PubMed1996

Assessing need for district nursing: study findings.

To determine whether an appropriate level of nursing care is being provided in the community, this study aimed to explore whether patients' needs are being identified through the referral system and whether those needs are being met.

Health Services Needs and Demand↗
PubMed1996

The use of the Nominal Group Technique in research with community nurses.

The use of group-based techniques to generate ideas and offer solutions to problems is commonplace in many disciplines and for many purposes. What were originally useful adjuncts to market research have become valuable and illuminating tools in education, policy and research. This paper will describe the use of one such technique, the Nominal Group Technique, and its practical application in bridging the gap between researchers and practitioners in one particular study of community nursing.

Community Health Nursing↗
PubMed1995

Characterization of two Epstein-Barr virus epitopes restricted by HLA-B7.

We have identified two epitopes for Epstein-Barr virus specific cytotoxic T lymphocytes (CTL) restricted by the common allele HLA-B7. They are EBNA 3C 881-9 (QPRAPIRPI) and EBNA 3A 379-387 (RPPIFIRRL). The epitopes conform well to the recently described motif for HLA-B7-binding peptides (Huckzo et al., J. Immunol. 1993. 151:2572). Titration of the peptides in CTL assays and detergent lysate binding assays revealed that extending the peptides at either the N or C terminus did not reduce their affinity for HLA-B7. This behavior contrasted with HLA-B51, which binds peptides with a similar motif to B7, and has identical amino acid residues at sites expected to form the "F" pocket of the peptide-binding groove. HLA-B51 also bound the peptide EBNA 3C 881-9, but was unable to bind peptides extended at the C terminus.

Amino Acid Sequence↗
PubMed1995

Differences in quantitative nuclear features between ductal carcinoma in situ (DCIS) with and without accompanying invasive carcinoma in the surrounding breast.

The aim of this study was to demonstrate differences in nuclear morphology between ductal carcinoma in situ (DCIS) without an invasive component and DCIS associated with invasive carcinoma in adjacent breast tissue. DCIS specimens of 60 non-comedo and 21 comedo cases were obtained from two groups of patients with or without invasive carcinoma of the breast. The analysis of DCIS nuclei was performed on formalin fixed deparaffinized thin sections stained with a stoichiometric stain following the Feulgen procedure. Nuclear features, related to nuclear size, shape and DNA distribution, were quantitatively characterized by high resolution image cytometry. Features associated with the presence of invasive carcinoma in the surrounding breast tissue were identified in DCIS nuclei (independent of nuclear grade). Features selected by the stepwise procedure of the discriminant function analysis were typically texture features describing the DNA distribution in the nucleus. A classification function based on the selected nuclear features predicted accurately the presence of invasive carcinoma in all comedo DCIS and in 80% of non-comedo DCIS cases. Our results indicate that quantitative nuclear features of DCIS nuclei are predictive of the accompanying invasion and may be helpful as a new tool in evaluation of DCIS patients.

Breast Neoplasms↗
PubMed1995

Malignancy-associated changes in the breast. Changes in chromatin distribution in epithelial cells in normal-appearing tissue adjacent to carcinoma.

Malignancy-associated changes (MACs) have been described as subtle morphologic changes in normal-appearing tissues adjacent to or distant from malignant tumors. MACs might be applicable as a marker of occult malignancy, increased risk of subsequent carcinoma or recurrence of tumor after therapy. The aim of this study was to verify the existence of MACs in normal-appearing breast tissue adjacent to breast carcinoma. Image cytometry measurements were performed on 4-microns sections cut from formaldehyde-fixed tissue blocks and stained with thionin-SO2 following the Feulgen procedure. Morphologically normal appearing breast lobules were analyzed in patients with benign (20 cases) and malignant breast disease (23 invasive and 11 in situ tumors). The chromatin distribution features of the epithelial nuclei in normal-appearing breast lobules differed between patients with benign and malignant breast disease. Changes in nuclear features, detected in epithelial nuclei from normal-appearing lobules in breasts resected for carcinoma, were defined as MACs. The frequency of MAC nuclei was low in benign tissues, increased in tissues with ductal carcinoma in situ and highest in tissues with invasive carcinoma. Based on the measurements of nuclei in normal-appearing lobules, it was possible to discriminate between patients with benign breast disease and patients with invasive carcinoma in 86% of cases.

Breast↗
PubMed1995

Histometric texture analysis of DNA in thin sections from breast biopsies. Application to the detection of malignancy-associated changes in carcinoma in situ.

OBJECTIVE: To evaluate histometric measurement of nuclear texture in breast biopsy sections in order to detect malignancy-associated changes in apparently normal tissue in the vicinity of carcinoma in situ. STUDY DESIGN: We previously showed that image cytometry measurements of nuclear features--foremost, texture features, describing the organization of Feulgenstained DNA in the cell--can be used to distinguish normal-appearing, diploid epithelial cells from patients with invasive carcinoma of the breast from those with benign biopsies. In that study, referred to as the "single cell analysis," images of at least 200 epithelial cells were acquired for each slide, and substantial user interaction was required to segment cells from each field. Location of isolated cells and interactive segmentation are both time-consuming procedures, particularly in breast tissue, where nuclei can be tightly clustered within a duct. With histometric texture analysis on the same specimens, segmentation of individual cells was ignored, and texture measurements were performed over the entire cluster of relevant cells. With this approach, ploidy information is not available, and touching and overlapping nuclei are included in the measurements. Measurement of histometric texture properties requires substantially less time (at least an order of magnitude) than individual cell measurement and, if ploidy information is not significant, may therefore provide a more practical means of analysis for tissue sections. RESULTS: Seventeen cases of invasive carcinoma and 17 cases of nonproliferative breast disease were examined. Using stepwise discriminant function analysis, slides were classified into one of the two groups with an accuracy of 88.6% in the case of single cell analysis and with an accuracy of 88.2% using histometric analysis. CONCLUSION: The existence of malignancy-associated changes in the breast was confirmed by an independent analysis of the same specimens. Although the two methods are not directly comparable, we found that histometric texture analysis performs at least as well as single-cell analysis for the detection of malignancy-associated changes in breast carcinoma.

Biopsy↗
PubMed1994

Adjuvant systemic therapy and survival after breast cancer.

BACKGROUND AND METHODS: We examined the effect of adjuvant systemic therapy on survival after breast cancer among the residents of the Canadian province of British Columbia. Data on survival were collected for all women in whom breast cancer was diagnosed in British Columbia during each of three calendar years chosen to represent different province-wide treatment recommendations: 1974, when no adjuvant systemic therapy was recommended; 1980, when adjuvant chemotherapy was recommended only for premenopausal women with node-positive disease; and 1984, when adjuvant chemotherapy was also recommended for premenopausal women with node-negative disease and lymphatic, vascular, or neural invasion and tamoxifen was recommended for postmenopausal women with involved lymph nodes or lymphatic, vascular, or neural invasion unless their tumors were negative for estrogen receptors. RESULTS: For women less than 50 years of age, disease-specific survival at seven years (i.e., with censoring of data on women who died from causes other than breast cancer) improved from 65.2 to 76.3 percent between 1974 and 1984 (P = 0.008), and overall survival improved from 64.8 to 74.6 percent (P = 0.02). For women from 50 through 89 years of age, disease-specific survival at seven years improved from 62.5 to 70.4 percent between 1980 and 1984 (P = 0.001), and overall survival improved from 53.9 to 58.3 percent (P = 0.05). The timing of the improvements in survival correlated with the introduction of adjuvant systemic therapy in each group. CONCLUSIONS: Survival among women with breast cancer improved significantly in a geographically defined population during the period when adjuvant systemic therapy became widely used.

Adult↗
PubMed1993

Conducting research interviews with elderly people by telephone.

Telephone interviews were employed by nurse researchers as a means of collecting data from elderly people following their discharge from hospital. The paper reviews the literature concerning interviews with elderly patients by telephone and recounts first-hand experience of the method on the basis of over 500 telephone interviews. Although some difficulties were encountered in conducting interviews with the hearing-impaired and the unwell, the method was found to be a cost-effective and useful means of obtaining follow-up data for research purposes. The prime factor in ensuring successful use of the method was the recruitment of subjects via personal interview prior to telephone contact.

Aged↗