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Biomedical subjects

J A Webb

Publications and source records attributed to J A Webb.

118 records · Page 7Linked to original sources
PubMedDate not supplied

Breast cancer screening among ethnically diverse low-income women in a general hospital psychiatry clinic.

Most low-income minority women do not obtain screening mammography on a regular basis. Compliance with recommended breast cancer screening guidelines may be even lower in women with psychiatric illnesses. We investigated compliance with breast cancer screening guidelines among 121 ethnically diverse low-income women recruited from a general hospital psychiatry clinic. Mammography and clinical breast examination (CBE) had been obtained in the previous year by 59% and 70% of the patients 40 years of age and older, respectively. Among patients 20 years of age and older, 42% reported monthly breast self-examination (BSE). Physician recommendation of mammography was the strongest predictor of having obtained both a mammogram and a CBE within the previous year. There was an inverse relationship between breast cancer knowledge and screening mammography. Patients who were Hispanic, more educated, more confident in performing BSE, and whose physicians recommended monthly BSE were more likely to perform BSE monthly. These results highlight the importance of physician recommendation of compliance with screening guidelines for early detection of breast cancer. Because psychiatric patients typically are treated by psychiatrists on a regular and frequent basis, psychiatrists are in a unique position not only to encourage cancer screening but also to monitor patient compliance with their recommendations.

Adult↗
PubMedDate not supplied

Feature and classifier fusion for 12-lead ECG classification.

Two methodologies, feature and classifier fusion, for the problem of computerized 12-lead electrocardiogram classification, are investigated. Firstly, the entire classification problem is subdivided into a number of smaller bi-dimensional ones. By employing bi-group Neural Network classifiers, independent feature vectors for each diagnostic class are examined individually and the output from each classifier are fused together to produce one single result. Secondly, two classifiers, namely the aforementioned and a decision tree, are fused together through a novel approach of a Specificity Matrix. This methodology addresses the problem of unresolved conflict during fusion of classifiers and aims to exploit the merits of each classifier and suppress their weaknesses. 290 validated 12-lead electrocardiogram recordings, comprising six diagnostic classes, were used to train, validate and test both methodologies. The framework of bi-group classifiers enhanced the overall performance by 12.0% in comparison with conventional approaches. In the second instance, the fusion of the two classifiers produced a performance level of 81.3%; superior to either classifier in isolation. This approach offers a viable solution to the unresolved problem of conflict between classifiers during fusion and can be extended readily to accommodate any number of diagnostic classes and classifiers.

Decision Trees↗
PubMedDate not supplied

Tamm-Horsfall glycoprotein excretion and aggregation during intravenous urography. Relevance to acute renal failure.

The effect of intravenous urography (IVU) on the excretion rate and precipitation of Tamm-Horsfall glycoprotein (THG) has been evaluated in 19 patients. Urine samples were collected immediately before the administration of contrast medium (U1) and then during the period of the excretion urogram (U2). The urinary THG: creatinine clearance ratio decreased in 15 patients by a mean of 28.2% (range 2.9-70.8) and increased in four by a mean of 22.8% (range 13.5-36.4). In 18 of 19 patients the amount of THG precipitated following the IVU decreased from an average of 75.6% of the total in U1 (range 2.2-100) to 19.5% (range 2.0-59) in U2. In the one exception the fraction precipitated was only 2.2% in U1 and 2.5% in U2. It is concluded that during routine IVU there is no marked increase in the excretion rate of THG. More importantly, the percentage of THG precipitated actually decreases.

Acute Kidney Injury↗
PubMedDate not supplied

Psychological impact of receiving negative BRCA1 mutation test results in Ashkenazim.

PURPOSE: Most DNA test results for breast/ovarian cancer susceptibility are negative. Because negative test results might be interpreted incorrectly and may have serious psychological and behavioral implications, determining the psychological impact of such results is important. METHODS: A community-based sample of 289 Ashkenazim was tested for 185delAG. The 199 mutation-negatives provided data at baseline and follow-up. Increased risk participants included those who received negative test results but remained at increased risk because positive family and/or personal histories of breast or ovarian cancer made the results uninformative. Average risk meant those who tested negative and had negative family and personal histories of breast or ovarian cancer. Using a logistic regression analysis, both groups' psychological distress levels were compared at baseline and at 1 and 6 months after notification of DNA test results. RESULTS: A logistic regression analysis showed significant but small differences in cancer-specific distress after 6 months between increased and average risk participants (P < 0.006). Increased risk participants reported more distress than average risk. General distress declined among all participants after 1 month. Although baseline and follow-up differences in cancer-specific distress obtained by the increased and average risk participants were statistically significant, none of the absolute levels observed reflected especially high degrees of stress. CONCLUSIONS: Receipt of negative DNA test results does not have a deleterious psychological impact, whether results are informative or uninformative.

Adult↗
PubMedDate not supplied

Real-time 'computer-evaded' pseudo-holography of computed tomography images.

An off-line method of dynamic imaging has been developed to facilitate visualization of three-dimensional tomographic data during real-time manoeuvres. Stereo-pair projection of multiple contiguous cross-sectional images on a conventional 625 line 50 Hz television raster has been investigated and pseudo-holograms have been displayed. A Cartesian stereo-pair projection model incorporating three degrees of rotational freedom and perspective has been developed. Computer simulations of the model have been conducted and the feasibility of adopting a simplified model has been examined. A condensed solution with two degrees of freedom, retaining partial perspective effects, has been simulated and analysed for worst-case errors. Reasonable projection accuracy has been demonstrated for small orientation angles. Specialized display hardware has been developed and a departure has been made from conventional picture-element (pixel) display methodology. Elemental quadrilaterals (rho-pixels), varying in size, shape and screen position, have been considered as an alternative to static square pixels in a rigid matrix. Joystick-controlled rho-pixel arrays have been implemented with parallelogram-shaped rho-pixels incorporated as a simplified case of quadrilateral projection. Dynamic stereo-pair projections of 64 X 64 rho-pixel arrays have been generated from computed tomography (CT) images and the results of phantom studies on a four-plane system are discussed.

Computer Simulation↗
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Breast cancer screening behaviors and intentions among asymptomatic women 50 years of age and older.

We examined predictors of (1) compliance with yearly mammography and clinical breast examination (CBE) and (2) intention to obtain mammography and CBE within the following year. Subjects were 312 asymptomatic female hospital employees, 50 years or older, who had participated in a free worksite breast cancer screening program. Mammograms and CBEs had been obtained by 79% and 76% of the subjects, respectively, during the preceding 12 months. The majority of the subjects indicated that they were very/extremely likely to obtain a mammogram and CBE in the next 12 months (88% and 87%, respectively). Multivariate analyses showed that perceived barriers to and physician recommendation of mammography were the strongest predictors of both breast cancer screening behaviors and intentions. Recency of participation in the educational component of the screening program was related to both compliance with mammography in the past 12 months and intention to obtain CBE in the next year. Having a first-degree female relative with a history of breast cancer was related to compliance with CBE in the past 12 months. Perceived efficacy of mammography was related to intention to obtain both mammography and CBE in the next year, and number of reasons for mammography was related to intention to obtain mammography in the next year. Our results suggest that physicians play a key role in motivating women to comply with breast cancer screening and that reducing barriers to obtaining mammography may increase use further.

Aged↗
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Skin cancer prevention and early detection intentions and behavior.

This longitudinal study examined predictors of (1) skin cancer prevention and early detection intentions and (2) compliance with recommendation for medical follow-up for suspicious skin lesions. Subjects were 324 hospital employees who were at increased risk for skin cancer and who participated in a worksite skin cancer screening program. Based on behavioral self-regulation theory and the Health Belief Model, multivariate analyses showed that optimism, perceived risk, reasons for doing skin self-examination (SSE), and SSE frequency prior to screening were the best predictors of intentions to engage in future health promotion behaviors (i.e., monthly SSE, regular sunscreen use, and participation in a skin cancer screening program the following year). Although our results also showed that optimism, reasons for doing SSE, and SSE frequency were the best predictors of compliance with medical follow-up, these three variables accounted for only a small amount of the variance in compliance with recommended follow-up care.

Adult↗
PubMedDate not supplied

Dispositional optimism, self-efficacy, and health beliefs as predictors of breast self-examination.

This cross-sectional study examined relationships among predictors of breast self-examination (BSE) derived from the Health Belief Model and behavioral self-regulation theory. Subjects were 427 gynecology outpatients. Although 64% indicated that they had practiced BSE at least once during the past year, only 27% indicated they practiced BSE monthly. The majority of the subjects knew about most of the recommended BSE steps. The most frequently endorsed reasons for completing BSE were early detection, recommendation from a doctor, and peace of mind. The most frequently endorsed barrier was forgetting/being too busy. Multivariate analysis showed that several psychological variables--including reasons for doing BSE, self-efficacy, and barriers to doing BSE--were related to frequency of BSE. Overall, the variables in this model accounted for about 37% of the variance in BSE frequency.

Adult↗
PubMedDate not supplied

Skin self-examination in a population at increased risk for skin cancer.

This cross-sectional study examined predictors of skin self-examination (SSE) in a population at increased risk for skin cancer. Subjects were 384 hospital employees participating in a worksite skin cancer screening. Although 61% reported that they performed SSE at least once during the past year, only 20% reported monthly SSE. Only a minority of the subjects were knowledgeable about most of the recommended SSE steps. Based on behavioral self-regulation theory, multivariate analysis showed that a variety of psychological factors (including optimism, knowledge about SSE, perceived self-efficacy, and number of reasons for doing SSE) correlated positively with frequency of SSE. Demographic variables accounted for about 6% of the variance in frequency of SSE. Overall, the variables in this model accounted for about 25% of the variance.

Adult↗