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Biomedical subjects

A Evans

Publications and source records attributed to A Evans.

At least 433 records · Page 24Linked to original sources
PubMedDate not supplied

Physical activity, physical fitness and respiratory function--exercise and respiratory function.

The aim of the study was to establish patterns of respiratory function in Northern Ireland and to examine the relationship between physical activity, physical fitness and respiratory function. We identified 1600 adults over 16 yr using 2 stage probability sampling. Physical activity was measured using a questionnaire, physical fitness from oxygen uptake while walking on a treadmill, and respiratory function using spirometry. The main outcome measures were a physical activity profile based on computer assisted interview, physical fitness by predicted VO2max, Forced Vital Capacity (FVC) and Forced Expiratory Volume (FEV1). We found that the main findings were of relationships between activity and FVC and FEV 1 which remained after adjustment for possible confounders in men, and between fitness and FVC and FEV 1 in both men and women although these were not sustained after adjustment for possible confounders.

Adolescent↗
PubMedDate not supplied

Fast inversion recovery for myelin suppression (FIRMS). A new MRI pulse sequence for highlighting cerebral gray matter.

The purpose of this study is to test a new pulse sequence, fast inversion recovery for myelin suppression (FIRMS) for its ability to improve the conspicuity of gray matter. Twenty-six seizure patients were scanned with FIRMS as well as standard sequences. Gray matter conspicuity was evaluated objectively using region-of-interest calculations, including image contrast, contrast ratios, and contrast:noise (C/N). In evaluation of the hippocampus and cortex, all objective measurements of conspicuity were highest for FIRMS. In five clinical cases of suspected cortical dysplasia, FIRMS improved delineation of pathology in positive cases and ruled out the diagnosis in negative cases. In a case of hippocampal sclerosis, FIRMS was able to demonstrate atrophy of the alveus. Fast inversion recovery for myelin suppression holds promise for its ability to highlight the cerebral cortex and hippocampus.

Cerebral Cortex↗
PubMedDate not supplied

Magnetic resonance imaging of intraspinal cystic lesions: a pictorial review.

Magnetic resonance imaging is the imaging modality of choice for the evaluation of diseases of the spinal cord and its coverings primarily because of improved lesion detection and characterization. The differentiation of intramedullary pathologic conditions (arising within the spinal cord) from extramedullary lesions (lying either within the thecal sac (intradural) or outside it (extradural) is usually straightforward. Although many lesions may occur in more than one compartment or may extend to involve more than one compartment simultaneously, accurate positioning of a detected lesion within the spinal canal and the assessment of its signal characteristics may help differentiate many of the more commonly encountered lesions and aid preoperative diagnosis. This pictorial review discusses the imaging findings and distinguishing features of a variety of intramedullary and extramedullary intraspinal cystic lesions with the use of magnetic resonance imaging. The imaging appearances are correlated with histologic findings where available.

Cysts↗
PubMedDate not supplied

Portable biofeedback apparatus for treatment of anal sphincter dystonia in childhood soiling and constipation.

Biofeedback is an effective treatment for anal sphincter dysfunction in many cases of childhood constipation and soiling. Conventional methodologies centre on clinic-based manometric apparatus but are compromised by equipment being thinly available and practice sessions often infrequent. To counter these shortcomings, we have designed a portable anorectal biofeedback apparatus (the Easograph) for domiciliary use. It can be lent to families, enabling carers to mediate what is an intrinsically sensitive procedure. In this paper, we provide a technical description of the device which is based on an inexpensive pressure transducer. Casework experience suggests it is reliable in operation and readily understood by users. In a pilot study of eight patients treated with the apparatus, five achieved bowel continence after lifelong soiling in one to eight weeks of daily practice. We believe this is an innovative approach that has good potential for treating faecal retentive and expulsive disorders in childhood associated with poor anal sphincter control.

Anal Canal↗
PubMedDate not supplied

Use of killed poliovirus vaccine in a routine immunization program in West Africa.

Combined diphtheria-tetanus-pertussis (DTP)-killed poliovirus vaccine was used (along with bacille Calmette-Guérin, measles, yellow fever, and smallpox vaccines) in a routine immunization program in a rural area of Senegal. A control group in a neighboring region received DTP vaccine without poliovirus vaccine. All immunizations were given at two sessions six months apart by a small mobile health team led by a nurse. Six months after the second dose of DTP-polio vaccine, 97.4%, 97.7%, and 90% of subjects two to eight months old at the start had detectable antibody to poliovirus types 1, 2, and 3, respectively. In the control group, 50%, 38%, and 80% of such subjects had antibody to poliovirus types 1, 2, and 3, respectively, acquired by natural infection during the study year. An average of 3.9 cases of paralytic poliomyelitis (range, one to 13) were observed annually at one dispensary in the test region from 1966 through 1979. From 1980 through 1982, since the immunization program has been in effect, only one case has been observed (in a nonimmunized child).

Africa, Western↗
PubMedDate not supplied

MRI of amygdala and hippocampus in temporal lobe epilepsy.

In this study we compared the results of qualitative visual analysis of MRI with volumetric studies of the amygdala (AM) and hippocampal formation (HF) in a group of 31 patients. Twenty-six patients with temporal lobe epilepsy (TLE) and six with non-TLE had MRI studies using a 1.5 T Gyroscan following a specific protocol for scan acquisition. The MR images were interpreted by two blinded radiologists and by a third if discrepancy arose. Volumetric studies were carried out by one or two raters. The volumetric measurements of AM and HF were accurate in lateralizing the epileptogenic area in patients with TLE, concordant with the EEG in 92%; there was no false lateralization. In those patients who underwent surgery, there was a correlation between the degree of mesial temporal sclerosis demonstrated by histopathology, the amount of volume reduction, and the asymmetry. In patients with non-TLE, there was no volume asymmetry of AM or HF. The MR qualitative assessment yielded positive lateralization in patients with TLE in 56%, conflicting lateralization in 20%, and lateralization contralateral to the focus in 12%. A hyperintense signal in mesial structures was found ipsilateral to the focus in 40% and contralateral in 12% of patients with TLE. Volumetric study improves the diagnostic yield of MRI evaluation in patients with TLE not related to gross structural lesions. The interrater variability is low and the data are accurate and reproducible. Because they are quantitative, volumetric studies permit better comparison of results in different subgroups of patients with TLE.

Adolescent↗
PubMedDate not supplied

A four-dimensional probabilistic atlas of the human brain.

The authors describe the development of a four-dimensional atlas and reference system that includes both macroscopic and microscopic information on structure and function of the human brain in persons between the ages of 18 and 90 years. Given the presumed large but previously unquantified degree of structural and functional variance among normal persons in the human population, the basis for this atlas and reference system is probabilistic. Through the efforts of the International Consortium for Brain Mapping (ICBM), 7,000 subjects will be included in the initial phase of database and atlas development. For each subject, detailed demographic, clinical, behavioral, and imaging information is being collected. In addition, 5,800 subjects will contribute DNA for the purpose of determining genotype- phenotype-behavioral correlations. The process of developing the strategies, algorithms, data collection methods, validation approaches, database structures, and distribution of results is described in this report. Examples of applications of the approach are described for the normal brain in both adults and children as well as in patients with schizophrenia. This project should provide new insights into the relationship between microscopic and macroscopic structure and function in the human brain and should have important implications in basic neuroscience, clinical diagnostics, and cerebral disorders.

Adolescent↗
PubMedDate not supplied

Drawtex: a unique dressing that can be tailor-made to fit wounds.

Drawtex is a new and innovative dressing using dispersion technology which works on capillary action. This promotes moist wound healing and provides the optimum environment at the wound interface. This dressing has the ability to absorb exudate 30 times it own weight. The unique capillary action draws the exudate away from the wound bed and into the core of the dressing from where it disperses into a second layer of Drawtex. The practitioner tailors the Drawtex to conform to the wound bed. Drawtex's non-adherence reduces the frequency of dressing change after the first week. This is not the only benefit as it is also very cost-effective at half the price of other modern dressing products.

Absorption↗
PubMedDate not supplied

Catheterization and urinary tract infections: microbiology.

Patients with urinary catheters are a substantial proportion of the total patient population and catheter care is an important area of nursing practice. Urinary tract infection associated with catheterization is known to be the most common nosocomial (hospital-acquired) infection. Urinary tract infections can be caused by exogenous microorganisms or endogenous faecal or urethral microorganisms. The different microorganisms which are responsible for causing urinary tract infections have particular characteristics. Many microorganisms form a biofilm, a living layer of cells which stick to the surfaces of the catheter and the catheter bag. Biofilms not only lead to urinary tract infections, but also they are associated with encrustation and catheter blockage. The article considers the microorganisms implicated in catheter-associated urinary tract infections and aims to develop an increased awareness of the characteristics of different pathogens which could lead to enhanced nursing practice and improved patient care.

Cross Infection↗
PubMedDate not supplied

Bladder washouts in the management of long-term catheters.

It has been estimated that 40-50% of patients with long-term catheters can suffer with catheter blockage. This not only causes distress to the patient but also increases the demands on community nurses' time and resources. Infection with bacteria such as Proteus causes the urine to become alkaline. Crystalline deposits can then form inside the catheter lumen which causes blockage. Nurses often manage blocked catheters with the use of bladder 'washouts' or bladder instillations. However, the literature is confused over the terminology of 'bladder washouts', instillations and irrigation and a great deal of controversy surrounds the effectiveness of these procedures. Crisis management of catheters occurs when nurses wait for catheters to become blocked before changing them; this often occurs at inconvenient times and patients frequently have to wait several hours before help is available. To avoid crisis management, nurses should aim to assess individual patients' 'pattern of catheter life' and plan changes accordingly. This would improve patient care and allow nurses to utilize their time more effectively.

Equipment Failure↗