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Biomedical subjects

P Potter

Publications and source records attributed to P Potter.

At least 19 recordsLinked to original sources

Phase 2 trial of sustained-release fampridine in chronic spinal cord injury.

STUDY DESIGN: Double-blind, randomized, placebo-controlled, parallel-group clinical trial. OBJECTIVE: Assess safety and efficacy of sustained-release fampridine in subjects with chronic spinal cord injury. SETTING: A total of 11 academic rehabilitation research centers in the United States. METHODS: A total of 91 subjects with motor-incomplete spinal cord injury (SCI), randomized to three arms: fampridine, sustained release, 25 mg b.i.d. (Group I), 40 mg b.i.d. (Group II), and placebo (Group III) for 8 weeks. OUTCOME MEASURES: Patient diary questionnaire, Ashworth score, American Spinal Cord Injury Association International Standards, International Index of Erectile Function, bladder and bowel management questionnaires, and Clinician and Subject Global Impressions (Clinician Global Impression of change, Subject Global Impression (SGI)). Safety was evaluated from adverse events, physical examinations, vital signs, electrocardiograms, and laboratory tests. RESULTS: In total, 78% of the subjects completed the study. More (13/30) discontinued from Group II than Group I (4/30) and Group III (3/31). The most frequent adverse events across groups were hypertonia, generalized spasm, insomnia, dizziness, asthenia, pain, constipation, and headache. One subject in Group II experienced a seizure. SGI changed significantly in favor of Group I (P=0.02). Subgroup analysis of subjects with baseline Ashworth scores >1 showed significant improvement in spasticity in Group I versus III (P=0.02). CONCLUSIONS: Group I showed significant improvement in SGI, and potential benefit on spasticity. The drug was well tolerated. Group II showed more adverse events and discontinuations.

4-Aminopyridine↗

Pharmacologic and anti-IgE treatment of allergic rhinitis ARIA update (in collaboration with GA2LEN).

The pharmacologic treatment of allergic rhinitis proposed by ARIA is an evidence-based and step-wise approach based on the classification of the symptoms. The ARIA workshop, held in December 1999, published a report in 2001 and new information has subsequently been published. The initial ARIA document lacked some important information on several issues. This document updates the ARIA sections on the pharmacologic and anti-IgE treatments of allergic rhinitis. Literature published between January 2000 and December 2004 has been included. Only a few studies assessing nasal and non-nasal symptoms are presented as these will be discussed in a separate document.

Animals↗

The association of prolonged breastfeeding and allergic disease in poor urban children.

The fact that breastfeeding may protect against allergic disease remains controversial, with hardly any reports from developing countries. This study investigated the association between allergic disease in children and prolonged breastfeeding. Data were collected from a 15% random sample of households from two poor suburbs of Cape Town, South Africa. Parents completed a validated International Study on Asthma and Allergies in Childhood questionnaire on allergic diseases for children aged 6-14 yrs. Other questions included breastfeeding duration, maternal smoking and parental allergy. Results were adjusted for possible confounders and for possible clustering within the household. Out of the 861 children included in the study, allergic disease in general, and hay fever in particular, were significantly less frequent in those with prolonged (> or =6 months) breastfeeding. There was a significant linear inverse association between breastfeeding duration and allergic disease in children without allergic parents, but not in children with an allergic predisposition. In conclusion, these results from a developing country suggest a protective effect of prolonged breastfeeding on the development of allergic disease, particularly hay fever, in children born to nonallergic parents. This protective effect was not found in children with an allergic predisposition.

Adolescent↗

Selection of military survival gears using thermal manikin and computer survival model data.

This study presents a practical example of the selection of protective equipment for 12-h cold survival on land and at sea using computer model and manikin data. The thermal immersion manikin was exposed to 19 realistic survival scenarios to estimate the thermal resistance of different survival systems. The computer survival model used specific environmental limits and anthropometric data from the target population in addition to the estimated manikin thermal resistance values to generate survival times. The results showed that the required 12-h survival time criteria were met for all dry land scenarios (> 2 Clo), but not for wet land or water scenarios ( < 1 Clo). Those data provided the basis for the selection of survival equipment and the development of survival strategies for aircrew.

Cold Temperature↗

Cranberry juice consumption may reduce biofilms on uroepithelial cells: pilot study in spinal cord injured patients.

STUDY DESIGN: A pilot study of 15 spinal cord injured patients. OBJECTIVE: To determine whether alteration of fluid intake and use of cranberry juice altered the bacterial biofilm load in the bladder. SETTING: London, Ontario, Canada. METHODS: Urine samples were collected on day 0 (start of study), on day 7 following each patient taking one glass of water three times daily in addition to normal diet, and on day 15 following each patient taking one glass of cranberry juice thrice daily. One urine sample was sent for culture and a second processed to harvest, examine by light microscopy and Gram stain non-squamous uroepithelial cells to generate bacterial adhesion per 50 cells data. RESULTS: The results showed that cranberry juice intake significantly reduced the biofilm load compared to baseline (P=0.013). This was due to a reduction in adhesion of Gram negative (P=0.054) and Gram positive (P=0.022) bacteria to cells. Water intake did not significantly reduce the bacterial adhesion or biofilm presence. CONCLUSION: The findings provide evidence in support of further, larger clinical trials into the use of functional foods, particularly cranberry juice, to reduce the risk of UTI in a patient population highly susceptible to morbidity and mortality associated with drug resistant uropathogens. SPONSORSHIP: This study was funded by Ocean Spray Cranberries, Lakeville, MA, USA.

Acids↗

Household smoking and bronchial hyperresponsiveness in children with asthma.

This study investigated whether household environmental tobacco smoke (ETS) exposure is associated with increased bronchial hyperresponsiveness (BHR) in children with asthma. Two hundred forty-nine children, ages 7-11 years, sampled from a larger group with reported asthma or multiple asthma symptoms identified in a community survey in Cape Town, underwent histamine challenge testing and had urinary cotinine measured. Parents were interviewed for information on smoking habits and a variety of covariates. Children with asthma whose mothers smoked had a lower frequency of BHR than asthmatic children of nonsmoking mothers, particularly if the mother smoked > or = 15 cigarettes daily. BHR was also less common among children sharing a house with four or more smokers vs. fewer or none. BHR was unrelated to paternal smoking. In contrast, FEV1 was lower among children whose mothers currently smoked. The findings do not support a mechanism whereby ETS exposure aggravates existing childhood asthma by increasing BHR. This association may be masked, however, by the degree to which mothers of asthmatic children adjust their smoking. The results are consistent with an adverse effect of maternal smoking on lung function in asthmatic children.

Asthma↗

Critical illness polyneuropathy.

Over the past three decades, there has been an increasing interest in cases of profound muscle weakness in critically ill, mechanically ventilated patients. Potential causes for these acute weakness syndromes are multiple and include disorders of the peripheral nerves, the neuromuscular junction, and muscle (Sliwa, 2000). This article will provide an overview of one potential cause of an acute weakness syndrome affecting peripheral nerves, critical illness polyneuropathy (CIP). A case study concerning a 32-year-old male who suffered multiple traumatic injuries, and who was treated for more than two years, is presented to illustrate the course of the syndrome. He required extensive interdisciplinary involvement to achieve independence in spite of ongoing neurological impairments.

Adult↗

Ofloxacin for the treatment of urinary tract infections and biofilms in spinal cord injury.

Forty two paraplegic and quadriplegic hospitalized spinal cord injured patients with urinary tract infections (UTI) were included in a double blind, randomized treatment study comparing 7 days ofloxacin (300 mg bd) with trimethoprim-sulphamethoxazole (TMPSMX; 160-800 mg bd) or an alternative, chosen because of resistance to TMPSMX. The 4-day clinical cure rate, defined as an asymptomatic patient with sterile urine, was 90% (19/21) with ofloxacin, significantly greater than 48% (10/21) for the comparison group (P=0.003) and the rate at end of therapy was 90% (19/21) with ofloxacin, against 57% (12/21) (P=0.015). Bacterial biofilms were detected on bladder epithelial cells in 39/41 (95%) patients. The biofilm score fell significantly following ofloxacin therapy (P < 0.001) or alternative therapy (P < 0.001). Ofloxacin treatment led to significantly more biofilm eradication than the other antibiotic group on day 4 (62 vs. 24%) (P=0.005) and day 7 (67 vs. 35%) (P=0.014). The study showed that ofloxacin was better than TMPSMX and alternatives at relieving clinical infection and eradicating bladder cell biofilms.

Administration, Oral↗

Early MRI findings in high grade glioma.

Magnetic resonance imaging (MRI) is more sensitive than computerized tomography in the detection of many intracerebral lesions; however, the significance of some MRI findings may be unclear. Over four years, nine patients, aged 40-79 years, have been encountered whose initial MRI scans were negative or had minimal abnormalities and soon thereafter had high grade glioma. Initial MRI was performed in eight patients for new-onset seizures and one patient for a focal deficit. MRI was negative in four of the patients and mildly abnormal in five of the patients (small areas of increased T2 and/or minimal enhancement). The initial diagnoses usually included inconclusive differentials of stroke and infection with neoplasm less frequently considered. Radiographic progression leading to the diagnosis of high grade glioma became evident on repeat MRI in 1-8 months with six patients showing progression within three months. All patients underwent surgery and had histologic diagnosis of glioma. Although MRI is quite sensitive, four of the initial scans were negative with reasonable quality studies. Conversely, in five of the initial scans, the tumors were detected when so small that the radiographic findings were not typically diagnostic. Glioma must be considered as a possible cause of initial seizures or new neurologic deficits in adults with normal or minimally abnormal MRI. In this group, seizures were the overwhelming hallmark of presentation. In such a clinical situation, close follow-up with short interval repeat MRI should be performed.

Adult↗

Field research on the relationship between stress and disease activity in rheumatoid arthritis.

We review empirical evidence from two field studies for the role of stressful life events in disease flare-ups among patients with rheumatoid arthritis (RA). RA patients were expected to be more vulnerable psychologically, and physiologically, to stressful events in their everyday lives than other arthritis patients without an autoimmune disease. Findings from two studies are reviewed both for their substantive contribution, but also to provide guidance on measurement issues in future field research of this kind. One study included 41 patients with RA, who were interviewed weekly and called to a clinic for blood work and joint examinations when their levels of interpersonal stress increased significantly. A second study used a similar design but included comparison samples of patients with osteoarthritis (OA) and healthy controls of similar age and the same gender as the RA sample. The findings provided support for the proposition that interpersonal stressors are predictive of increases in disease activity. Not all RA patients, however, showed these relationships, and there was evidence that some participants with OA who were depressed also showed higher disease activity following interpersonal stressors. Significant individual differences in the stress-disease relationship were uncovered that deserve greater attention in future studies. Important improvements in the assessment of stressful events and refinements in panel study design are also presented as guides to research on the role of stress in disease processes.

Adaptation, Psychological↗

Consultant appointments. Appoint well made.

The appointment of consultants is of crucial importance to a trust's success. The introduction of mandatory training for all consultants involved in making appointments has proved successful, despite initial scepticism. The use of a competency framework in assessing candidates has eased the selection process.

Clinical Competence↗

Relapses in the Guillain-Barré syndrome after treatment with intravenous immune globulin or plasma exchange.

To clarify the question of whether Guillain-Barré syndrome (GBS) patients treated with intravenous immune globulin (i.v.IG) relapse at a higher frequency than those treated with plasma exchange (PE), 54 patients with GBS were studied retrospectively. A higher frequency of relapses was noted in the PE-treated patients than in those receiving i.v.IG. The presence of an associated medical condition correlated with an increased risk of relapses, while earlier onset of treatment resulted in a decrease of relapses of GBS. This study found no support for prior suggestions of increased relapses in patients with GBS treated with i.v.IG as opposed to those treated with PE.

Adult↗

Multiple signals regulate the intracellular trafficking of HLA-DM in B-lymphoblastoid cells.

Peptide loading by major histocompatibility complex (MHC) class II molecules occurs in the endocytic pathway and is critically dependent upon the function of the class II-related molecule human leucocyte antigen-DM (HLA-DM). We have previously shown that a tyrosine-based lysosomal targeting signal present in the cytoplasmic tail of DMB has the capacity to target HLA-DM to peptide-loading compartments in HeLa cells. Here we investigate the importance of this signal in directing HLA-DM to processing compartments in professional antigen-presenting cells. We reconstituted a DMB-negative B-lymphoblastoid cell line with native or targeting-deficient DMB and show that in the absence of its tyrosine signal, DMB-Y230A is as efficient as the wild-type molecule in inducing MHC class II SDS stable dimer formation; restoring expression of the conformation-dependent DR3 epitope 16:23; the removal of CLIP; and accessing lysosomal peptide-loading compartments. By transient transfection in HeLa cells we show that Ii is able to compensate for loss of DMB-encoded targeting information. These data imply that in cells expressing physiological levels of class II, Ii and DM, there is sufficient association with Ii to direct the majority of DM into the endocytic pathway. Thus MHC class II and HLA-DM may follow similar intracellular trafficking pathways on route to antigen-processing compartments.

Antigens, Differentiation, B-Lymphocyte↗

Examination of changes in interpersonal stress as a factor in disease exacerbations among women with rheumatoid arthritis.

OBJECTIVE: This study examined the effects of change in interpersonal stress on disease activity among 41 women with rheumatoid arthritis (RA). METHODS: Measures of everyday stressful events and perceived stress were collected weekly for twelve weeks and related to disease activity in a series of pooled time-series regression analyses. RESULTS: Increases in the number of interpersonal stressors in the same week and one week prior were associated with increases in disease activity. Pain from joint tenderness also was significantly related to a decrease in stressful events one week later. A subgroup of 20 patients showed a significant increase in interpersonal stress from baseline during the course of the study. For this group, significant elevations in DR + CD3 cells, sIL-2R, clinician's rating of disease, and self-reports of joint tenderness were found during the week of increased interpersonal stress. CONCLUSIONS: Interpersonal stress appears to be associated with increases in disease activity among RA patients.

Adult↗

Employee reactions to ergonomic job design: the moderating effects of health locus of control and self-efficacy.

A field survey of 180 municipal government office employees (82% women, 21-75 years old) investigated the potential moderating effects of internal health locus of control (HLOC) and self-efficacy on employees' reactions to ergonomic job design. Internal HLOC moderated the associations between ergonomic job design and somatic complaints and turnover intentions, and, to a lesser extent, job satisfaction. Self-efficacy moderated the associations between job design and job satisfaction, somatic complaints, and, to a lesser extent, persistent pain. Employees with low self-efficacy or low internal HLOC were influenced more by their physical job conditions than those with high self-efficacy or high internal HLOC. Implications for the ergonomic design of offices are discussed.

Adult↗