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Biomedical subjects

S Rogers

Publications and source records attributed to S Rogers.

At least 19 recordsLinked to original sources
PubMed2000

Influence of complete spinal cord injury on skeletal muscle mechanics within the first 6 months of injury.

In this study we examined the influence of complete spinal cord injury (SCI) on the mechanical characteristics of skeletal muscle in vivo within 6 months of the injury. Surface electrical stimulation (ES) was applied to the left m. quadriceps femoris of patients at 6, 11 and 24 weeks after injury. Surface ES was also applied to seven able-bodied controls (AB) at two time points 18 weeks apart. ES consisted of 2 bouts of 20, 1-s isometric contractions with 2 s and 2 min of rest between contractions and bouts, respectively. The time from 20-80% of peak torque (rise time) and the half relaxation time (1/2 RT) were determined for the first and for the last few contractions. Force loss over repeat contractions was greater in SCI than AB (27% vs 95%; P = 0.0001), and did not change over the 18-week period. Rise time did not change over repeat contractions, was not different between groups, and nor did it change over the 18-week period (range: 150-172 ms). 1/2 RT showed several group differences. Overall, 1/2 RT was longer at the beginning of ES in SCI than AB [mean (SE) 133 (15) ms vs 90 (6) ms, P = 0.037]. Slowing of relaxation time with force loss over repeat contractions was found in SCI at 24 weeks after injury [167 (18) ms, P = 0.016], but not at 6 [128 (14) ms] or 11 [145 (12) ms] weeks after injury. AB, in contrast, showed prolonged relaxation times, with force loss at both time points [115 (10) ms and 113 (11) ms; P = 0.0001]. The results indicate that SCI alters the relaxation but not contractile properties of mixed skeletal muscle within the first 24 weeks of injury. Altered calcium handling and contraction-induced fiber injury are suggested to explain the slower relaxation time per se, and the prolonged relaxation with force loss observed after SCI.

Adolescent↗
PubMed1999

General practitioners' perceptions of effective health care.

OBJECTIVES: To explore general practitioners' perceptions of effective health care and its application in their own practice; to examine how these perceptions relate to assumptions about clinicians' values and behaviour implicit in the evidence based medicine approach. DESIGN: A qualitative study using semistructured interviews. SETTING: Eight general practices in North Thames region that were part of the Medical Research Council General Practice Research Framework. PARTICIPANTS: 24 general practitioners, three from each practice. MAIN OUTCOME MEASURES: Respondents' definitions of effective health care, reasons for not practising effectively according to their own criteria, sources of information used to answer clinical questions about patients, reasons for making changes in clinical practice. RESULTS: Three categories of definitions emerged: clinical, patient related, and resource related. Patient factors were the main reason given for not practising effectively; others were lack of time, doctors' lack of knowledge and skills, lack of resources, and "human failings." Main sources of information used in situations of clinical uncertainty were general practitioner partners and hospital doctors. Contact with hospital doctors and observation of hospital practice were just as likely as information from medical and scientific literature to bring about changes in clinical practice. CONCLUSIONS: The findings suggest that the central assumptions of the evidence based medicine paradigm may not be shared by many general practitioners, making its application in general practice problematic. The promotion of effective care in general practice requires a broader vision and a more pragmatic approach which takes account of practitioners' concerns and is compatible with the complex nature of their work.

Adult↗
PubMed1999

Answers to unasked questions: writing in the margins.

This qualitative study is a secondary analysis of comments spontaneously provided by participants in a quantitative survey. Narrative comments were written by 25% (n = 205) of the adults with multiple sclerosis who responded to the survey. Forms of unsolicited written comments included responses to questions written in the margins of the questionnaires and narratives on blank booklet pages. The purpose of this study was to apprehend what participants were telling us, particularly in the responses that they had written in the margins. Qualitative methods were used to identify and explore major categories in the participants' comments. Those who wrote unsolicited comments perceived their economic resources as less adequate, were experiencing greater family and social demands related to their illness, and were more likely to live in a nonmetropolitan county than other respondents. Secondary analysis of this rich qualitative data enhances the depth of our understanding of the person's experience with chronic illness.

Adaptation, Psychological↗
PubMed1999

Radiofrequency ablation lesions in a pig liver model.

BACKGROUND: Radiofrequency (RF) ablation has been reported as a means of liver tumor destruction. This study evaluates the use of ultrasound monitoring of radiofrequency lesion creation and describes the morphology, histologic characteristics, and vascular effects of radiofrequency ablations in a pig liver model. MATERIALS AND METHODS: Hemodynamic monitoring was established and laparotomies were performed in 50-kg pigs. Under ultrasound guidance, radiofrequency needle probes were placed in the liver at predetermined locations. Radiofrequency energy was applied over 15 min to generate lesions 3 cm in diameter. Eighty lesions were generated in 10 animals. At the completion of the experiment, the lesions were examined with ultrasound and then excised for CT, gross, and histologic examination. RESULTS: There were no adverse systemic effects. Ultrasound imaging demonstrated the size, shape, and position of the lesions. Gross examination demonstrated a core of ablated tissue with a surrounding 1- to 2-mm hemorrhagic perimeter. Lesion volumes averaged 12.8 cc(3) (range 5-34 cc(3)). Final lesion shape and size were frequently altered by the cooling effect of local blood flow. Histologic stains demonstrated microvascular thrombosis and coagulative necrosis within the lesions. There appeared to be 100% cellular destruction within the lesion by cytochemical staining. CONCLUSIONS: We demonstrated that RF ablation is capable of killing large volumes of normal liver tissue; however, local vasculature plays a significant a role in defining the ultimate size and shape of the lesion created. This may interfere with the utility of radiofrequency ablation as a modality for local tumor control.

Animals↗
PubMed1999

A simple means of increasing muscle size after spinal cord injury: a pilot study.

This study tested that hypothesis that skeletal muscle within a year of spinal cord injury (SCI) would respond to intermittent high force loading by showing an increase in size. Three males about 46 weeks post clinically complete SCI underwent surface electrical stimulation of their left or right m. quadriceps femoris 2 days per week for 8 weeks to evoke 4 sets of ten isometric or dynamic actions each session. Conditioning increased average cross-sectional area of m. quadriceps femoris, assessed by magnetic resonance imaging, by 20+/-1% (p = 0.0103). This reversed 48 weeks of atrophy such that m. quadriceps femoris 54 weeks after SCI was the same size as when the patients were first studied 6 weeks after injury. The results suggest that skeletal muscle is remarkably responsive to intermittent, high force loading after almost one year of little if any contractile activity.

Adult↗
PubMed1999

Comparison of laparoscopic ultrasonography and fluorocholangiography in 300 patients undergoing laparoscopic cholecystectomy.

BACKGROUND: This study compares laparoscopic ultrasonography to fluorocholangiography in detecting common bile duct (CBD) stones and delineating biliary anatomy. METHODS: A prospective nonrandomized study of 300 consecutive patients undergoing laparoscopic cholecystectomy in a university hospital was performed. After port placement but before dissection, laparoscopic ultrasonography of the extrahepatic CBD was performed in both transverse and longitudinal planes. Cystic duct fluorocholangiography was attempted in all patients. RESULTS: Of 300 patients, CBD stones were detected in 26 (9%) with 25 of these (96%) detected on laparoscopic ultrasonography. Sonography identified the location and size of the CBD as well as anomalous anatomy prior to dissection. No CBD injuries were encountered. End-fire transducers were easier to use than rigid or flexible side-fire transducers; all gave excellent image quality. CONCLUSIONS: In this large study, laparoscopic ultrasonography and fluorocholangiography were equally sensitive in detecting CBD stones. Sonography delineates the biliary anatomy noninvasively and does not require dissection or opening of the biliary system. Laparoscopic ultrasonography may improve the safety of laparoscopic cholecystectomy, especially in cases of acute inflammation or distorted anatomy.

Cholangiography↗
PubMed1999

Survival and patterns of recurrence in 200 oral cancer patients treated by radical surgery and neck dissection.

The outcome of 200 patients with squamous cell carcinoma of the oral/oropharyngeal mucosa managed by primary radical surgery and simultaneous neck dissection and followed for 2.2-8.5 years is reported and related to the pathological features. Ninety-nine patients (50%) had cervical lymph node metastases including 16 (8%) with bilateral metastases. Actuarial (life tables) survival analysis showed the overall 2-year survival probability was 72%, falling to 64% at 5 years. The 5-year survival probability was 81% for patients without metastasis, 64% for patients with intranodal metastases and 21% for patients with metastases showing extracapsular spread. A total of 60 patients (30%) died of/with their cancer: 36 (18%) of local recurrence; 4 (2%) of a metachronous primary tumour; 14 (7%) of regional disease, and 6 (3%) with systemic metastases. A further 15 patients (8%) had relapsed but were clinically disease-free after additional surgery. In all, 7% of the series developed metachronous primary tumours. In addition to nodal metastasis, survival was related to the site and stage of the primary tumour, the histological grade and pattern of invasion, status of the resection margins and pathological TNM stage. For patients with lymph node metastasis, extracapsular spread was an important indicator of tumour behaviour and we recommend its use as a criterion for pathological N staging.

Adult↗
PubMed1999

Necrobiosis lipoidica: only a minority of patients have diabetes mellitus.

Although it is commonly accepted that necrobiosis lipoidica (NL) is associated with diabetes mellitus (DM), there is some controversy regarding the degree of this association. In a retrospective review of 65 patients with NL attending our dermatology out-patient clinics we found that just seven (11%) were known to have DM at the time of presentation. Seven further patients (11%) were diagnosed as having impaired glucose tolerance/DM at presentation and over a 15-year follow-up period. Thus, only a minority of our patients with NL had DM.

Administration, Topical↗
PubMed1999

Large increments in psoralen-ultraviolet A (PUVA) therapy are unsuitable for fair-skinned individuals with psoriasis.

The ideal psoralen-ultraviolet A (PUVA) regimen for chronic plaque psoriasis has yet to be established. There are four components to a PUVA regimen: the dose of psoralen, the starting dose of UVA, the frequency of treatment and the incremental UVA dose protocol. Recent studies have been directed at trying to optimize the efficacy of PUVA while minimizing acute side-effects and the risk of cutaneous carcinogenesis, believed to be independently related to the cumulative dose of UVA and the total number of treatments. The British Photodermatology Group recommends two twice-weekly PUVA regimens: one starts with 50% of the minimal phototoxic dose (MPD) and uses weekly increments of 40%, 30%, 25%, 20%, 15%, 10% and 5% of the previous dose to a maximum of 14.5 J/cm2; the other starts with a fixed dose based on skin type and uses weekly dose increments of 40%, decreasing to 20% once erythema develops. We undertook a prospective randomized controlled trial comparing these regimens in 85 Irish patients. The clearance rate with the MPD regimen was lower than with the skin type regimen, 67.5% vs. 95% (P < 0.05). The reasons for treatment failure were grade 3 erythema and severe PUVA itch. There was a trend suggesting that patients with skin types I and II, but not skin type III, required a higher cumulative UVA dose and fewer exposures to clear with the MPD regimen than the skin type regimen, although this did not reach statistical significance. Grades 2 or 3 erythema were very common in both treatment groups (52. 5% of the skin type group and 45% of the MPD group). This is the third study to suggest that patients with skin types I and II receive a higher total UVA dose when the starting dose is 50-70% of the MPD (rather than 0.5 J/cm2 for skin type I and 1.0 J/cm2 for skin type II) and when large dose increments are used. We suggest that smaller dose increments should be used in patients with skin types I and II.

Adult↗
PubMed1999

Potential interventions for the prevention of childhood pneumonia in developing countries: improving nutrition.

Acute respiratory infections are the leading cause of childhood death in developing countries. Current efforts at mortality control focus on case management and immunization, but other preventive strategies may have a broader and more sustainable effect. This review, commissioned by the World Health Organization, examines the relations between pneumonia and nutritional factors and estimates the potential effect of nutritional interventions. Low birth weight, malnutrition (as assessed through anthropometry), and lack of breast-feeding appear to be important risk factors for childhood pneumonia, and nutritional interventions may have a sizeable effect in reducing deaths from pneumonia. For all regions except Latin America, interventions to prevent malnutrition and low birth weight look more promising than does breast-feeding promotion. In Latin America, breast-feeding promotion would have an effect similar to that of improving birth weights, whereas interventions to prevent malnutrition are likely to have less of an effect. These findings emphasize the need for tailoring interventions to specific national and even local conditions.

Breast Feeding↗
PubMed1999

Fractional allele loss indicates distinct genetic populations in the development of squamous cell carcinoma of the head and neck (SCCHN).

Loss of heterozygosity (LOH) had been widely used to assess genetic instability in tumours and a high LOH on chromosome arms 3p, 9p and 17p has been considered to be a common event in squamous cell carcinoma of the head and neck (SCCHN). We have investigated LOH in 52 SCCHN using a range of microsatellite markers. LOH was observed in 69% of individuals on 17p using seven markers, in 64% of individuals on 3p using 17 markers and in 61% of individuals on 9p using 11 markers. Fractional allele loss (FAL) has been calculated for each tumour (FAL is the number of chromosomal arms showing LOH divided by the number of informative chromosomal arms) and a median FAL value of 0.25 was obtained in the 52 SCCHN studied. The LOH data were examined on the basis of FAL scores: low FAL (LFAL), 0.00-0.19; medium FAL (MFAL), 0.20-0.32; high FAL (HFAL), 0.33-0.88. HFAL tumours demonstrated a significantly higher LOH on chromosome arms 3p, 9p and 17p, with 94% LOH on 3p, 94% on 9p and 100% on 17p compared with LFAL tumours. Six of the 16 patients in the LFAL group were found to have no LOH on 3p, 9p or 17p and of these four had LOH at other sites, on chromosomes 2p25-p24, 5q21-22, 7pter-p22, 8q13-q22.1, 11q23.3, 13q32, 17q, 18p11.21, 18q21.31 and 19q12-q13.1. These results indicate that LFAL patients form a subset of SCCHN tumours with distinct molecular initiating events which may represent a discrete genetic population.

Alleles↗
PubMed1999

Physical and occupational therapy.

Occupational and physical therapists are concerned with an infant's ability to perform in object play and manipulation, self-care, mobility, and social function. Within the realm of child psychiatry, occupational and physical therapists contribute to a comprehensive assessment by providing in-depth neuromotor, sensory processing, and functional or adaptive skill analyses. The three theoretic approaches presented in this article represent the current trends within infant and young child assessment in the fields of occupational and physical therapy. In the past, therapists primarily used neuromotor or developmental assessments. Although these assessments have proven to be adequate for discrimination between children with developmental delays and those who are typically developing, they have not been as useful in documentation of progress in treatment or in providing an understanding of qualitative aspects of movement. Qualitative assessments that are more sensitive to change and to the complexity of functional skills have grown with the development of more sophisticated early-intervention strategies. Assessments based on dynamic systems theory allow therapists to quantify abilities, document subtle changes over time, and provide information on the qualitative aspects of movement. Therapists, however, continue to regularly employ assessments from multiple theoretic approaches to complete comprehensive evaluations.

Child, Preschool↗
PubMed1999

Analysis and interpretation of short tandem repeat microvariants and three-banded allele patterns using multiple allele detection systems.

The Palm Beach County Sheriffs Office (PBSO) Crime Laboratory and the Alabama Department of Forensic Sciences (ADFS) have validated and implemented analysis of short tandem repeat (STR) sequences on casework using silver staining kit and SYBR Green I detection systems and are presently validating fluorescently tagged STR alleles using the Hitachi FMBIO 100 instrument. Concurrently, the Broward County Sheriff's Office (BSO) Crime Laboratory is validating the ABI Prism310 Genetic Analyzer capillary electrophoresis STR detection system (ABI CE310) from Perkin Elmer Applied BioSystems. During the course of analyzing over 10,000 individuals for the STR loci CSF1PO, TPOX and THO1 (CTT) using silver staining for allele detection, 42 samples demonstrated alleles that were "off ladder," contained three-banded patterns at a single locus, or exhibited an apparent THO1 "9.3,10" allele pattern. PBSO, ADFS and BSO Crime Laboratories have collaborated on the verification of the allele patterns observed in these 42 samples using the following allele detection systems: (1) manual silver staining, (2) SYBR Green I staining, and/or (3) fluorescently tagged amplified products separated by polyacrylamide gel electrophoresis or capillary electrophoresis followed by laser detection. Regardless of the CTT allele detection system utilized, concordant results were obtained for 41 of the 42 samples. The only exception was a sample in which a wide band within the THO1 locus was identified as a THO1 "9.3, 10" genotype by silver staining kit and SYBR Green I staining but was verified to be a THO1 "9.3" homozygote by all other allele detection systems. Manual allele detection could readily identify microvariants, as a visual assessment of stained gels clearly shows that alleles do not migrate coincident with well-characterized allele size standards. As would be predicted, however, the manual detection systems did not provide adequate resolution to approximate the basepair size for off-ladder variants. All fluorescent software program systems were consistent in designating alleles "not in range" or "off ladder," thereby indicating true microvariants. All single-locus three-banded patterns were detected using all of the STR multiplex systems. In addition, individual locus-specific primers verified multiplexed amplified products were specific for the locus in question.

Alleles↗