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Biomedical subjects

R E Stewart

Publications and source records attributed to R E Stewart.

At least 19 recordsLinked to original sources
PubMed2005

Comparing self-report, clinical examination and functional testing in the assessment of work-related limitations in patients with chronic low back pain.

PURPOSE: To compare the work-related limitations assessed using self-report, clinical examination and functional testing in patients with chronic low back pain (CLBP). METHODS: Work-related limitations of 92 patients were assessed using self-report, clinical examination and functional testing. To obtain the assessed limitations the patient (self-report), the physician (clinical examination) and a trained evaluator (functional testing) completed a scorings form about the work-related limitations of the patient. The Isernhagen Work Systems Functional Capacity Evaluation (IWS FCE) was used to obtain the functional testing results. A kappa value of more than 0.60, absolute agreement of more than 80% and ICC of more than 0.75 were considered as acceptable. RESULTS: Little agreement and correlation among self-report, clinical examination and functional testing were found for the assessment of work-related limitations. Self-reported limitations were considerably higher than from those derived from clinical examination or functional testing. Additionally, the limitations derived from the clinical examination were higher than those derived from the IWS FCE. CONCLUSION: Comparing self-report, clinical examination and functional testing for assessing work-related limitations in CLBP patients showed large considerable differences in limitations. Professional health care workers should be aware of these differences when using them in daily practice.

Adult↗
PubMed2005

[Reduction in the consumption of benzodiazepines due to a letter to chronic users from their own general practitioner].

OBJECTIVE: To investigate the effectiveness of a minimal intervention in reducing the volume of prescription of benzodiazepines at the regional level. DESIGN: Prospective. METHOD: Patients on compulsory health insurance who had received 180 or more daily doses of benzodiazepines in the course of one year received a letter from their general practitioner (GP) with information about the risks of chronic use, the advice to reduce or stop use, and an invitation to make an appointment to discuss the problem. This intervention took place in 19 GP practices in East Groningen. A reminder was sent six months later to the patients who had not responded in 9 randomly selected GP-practices. Thirty-seven practices in East Groningen and 91 practices in Northwest Groningen served as controls. Outcome measures were: (a) the percentage of patients who stopped, and (b) the change in average benzodiazepine consumption. RESULTS: During the period 6-12 months after the first letter in the intervention group (n = 1343), 11.3% of the patients (95% CI: 9.6-13.1) received no prescription whatsoever for benzodiazepines compared to 5.4% (4.6-6.3) and 4.9% (4.2-5.5) in East Groningen (n = 2932) and in Northwest Groningen (n = 4562), respectively. The average decrease in prescription volume was 13% (-9.9 to -15.1) in the intervention group compared to 3% (-0.1 to -4.1) and 3% (-1.5 to -4) in the control groups. The reminder sent half a year later had no additional effect. CONCLUSION: The informative letter from the GP to chronic users of benzodiazepines with the advice to stop or reduce this use was effective.

Anti-Anxiety Agents↗
PubMed2005

Digital correction of magnification in pelvic x rays for preoperative planning of hip joint replacements: theoretical development and clinical results of a new protocol.

The introduction of digital radiological facilities leads to the necessity of digital preoperative planning, which is an essential part of joint replacement surgery. To avoid errors in the preparation and execution of hip surgery, reliable correction of the magnification of the projected hip is a prerequisite. So far, no validated method exists to accomplish this. We present validated geometrical models of the x-ray projection of spheres, relevant for the calibration procedure to correct for the radiographic magnification. With help of these models a new calibration protocol was developed. The validity and precision of this procedure was determined in clinical practice. Magnification factors could be predicted with a maximal margin of error of 1.5%. The new calibration protocol is valid and reliable. The clinical tests revealed that correction of magnification has a 95% margin of error of -3% to +3%. Future research might clarify if a strict calibration protocol, as presented in this study, results in more accurate preoperative planning of hip joint replacements.

Algorithms↗
PubMed2002

Medical students' experiences of diseases in internal medicine in university and community hospitals.

Because medical students in The Netherlands should achieve common national objectives, it is important to know whether clinical experiences in different hospitals are comparable. The research questions were: (1) Do students achieve learning experiences of the required diseases during the internship in Internal Medicine and to what extent do they achieve these experiences? (2) Are there differences between the diseases experienced at a university hospital and at community hospitals? Completed logbooks of students were analysed; the percentage of students that achieved the required diseases and the mean number of experiences of diseases were calculated. A t-test was done to test for differences. Medical students in the university and in community hospitals get broad experience (76-131%) of the required diseases. In both hospitals there are many students who are not achieving the requirements, but the mean number of experiences of students at the community hospitals is higher than those at the university hospital. To eliminate the differences between students from the university hospital and the community hospitals, the educational programmes within both hospitals should be adjusted.

Clinical Competence↗
PubMed2001

The reliability of logbook data of medical students: an estimation of interobserver agreement, sensitivity and specificity.

OBJECTIVE: Logbooks are widely used in medical schools as an evaluation tool to assess students' progress towards objectives. To estimate whether students fill in their logbooks reliably, we measured interobserver agreement by comparing doctors' data and students' data. METHOD: Completed logbooks were collected at two subdivisions of the department of Internal Medicine at the University Hospital of Groningen. The logbook contains 231 preprinted diseases. Doctors and students recorded the diseases they had encountered. Interobserver agreement, expressed by the Jaccard coefficient (J), was calculated for the complete set of diseases and for a subset of core diseases. To assess the kinds of errors which students made, sensitivity and specificity were determined. RESULTS: Logbook data of doctors and students are not fully consistent (mean J for the complete set of diseases was.23 and for the core diseases.36). The quality of the logbook data is high in the sense that students do not record many false identifications (mean specificity for the complete set of diseases and for the core diseases were.96 and.93, respectively); the quality is poor in the sense that students do not record all the diseases which could be seen at the department (mean sensitivity for the complete set of diseases is.36 and for the core diseases it is.51). CONCLUSION: This study shows inconsistencies in recording diseases in a logbook by students compared with doctors. In particular the diseases which are present at a department are under-reported by students. Supervision and feedback are important mechanisms to optimize the students' use of (1) all diseases which could be encountered and (2) the logbook.

Curriculum↗
PubMed2001

Serologic survey of Brucella spp. antibodies in some marine mammals of North America.

A serologic survey of anti-Brucella spp. antibodies was undertaken on 2,470 samples of 14 North American marine mammal species collected between 1984-97. Serum or blood from eight species of cetaceans and six species of pinnipeds was sampled from Pacific, Atlantic, and Arctic oceans. Two competitive enzyme-linked immunosorbent assays (C-ELISA's), using specific monoclonal antibodies to Brucella abortus cell wall components, were used to detect anti-Brucella spp. antibodies in the samples. Sera from 33 cetaceans and 61 pinnipeds gave inhibition values, in one or both of the tests, which exceeded the threshold that indicates Brucella spp. exposure in cattle. Seropositive animals were identified from Pacific, Atlantic, and Arctic oceans. While Brucella spp. was not isolated, differences in the response of seropositive cetacean and pinniped sera in the two assays suggest that two antigenically distinct species or biovars of Brucella spp. are present. No pathology consistent with clinical brucellosis was noted in any of the animals tested although detailed examination was not conducted on all carcasses.

Animal Diseases↗
PubMed2000

Development of rat chorda tympani sodium responses: evidence for age-dependent changes in global amiloride-sensitive Na(+) channel kinetics.

In rat, chorda tympani nerve taste responses to Na(+) salts increase between roughly 10 and 45 days of age to reach stable, mature magnitudes. Previous evidence from in vitro preparations and from taste nerve responses using Na(+) channel blockers suggests that the physiological basis for this developmental increase in gustatory Na(+) sensitivity is the progressive addition of functional, Na(+) transduction elements (i.e., amiloride-sensitive Na(+) channels) to the apical membranes of fungiform papilla taste receptor cells. To avoid potential confounding effects of pharmacological interventions and to permit quantification of aggregate Na(+) channel behavior using a kinetic model, we obtained chorda tympani nerve responses to NaCl and sodium gluconate (NaGlu) during receptive field voltage clamp in rats aged from 12-14 to 60 days and older (60+ days). Significant, age-dependent increases in chorda tympani responses to these stimuli occurred as expected. Importantly, apical Na(+) channel density, estimated from an apical Na(+) channel kinetic model, increased monotonically with age. The maximum rate of Na(+) response increase occurred between postnatal days 12-14 and 29-31. In addition, estimated Na(+) channel affinity increased between 12-14 and 19-23 days of age, i.e., on a time course distinct from that of the maximum rate of Na(+) response increase. Finally, estimates of the fraction of clamp voltage dropped across taste receptor apical membranes decreased between 19-23 and 29-31 days of age for NaCl but remained stable for NaGlu. The stimulus dependence of this change is consistent with a developmental increase in taste bud tight junctional Cl(-) ion permeability that lags behind the developmental increase in apical Na(+) channel density. A significant, indirect anion influence on apical Na(+) channel properties was present at all ages tested. This influence was evident in the higher apparent apical Na(+) channel affinities obtained for NaCl relative to NaGlu. This stimulus-dependent modulation of apical Na(+) channel apparent affinity relies on differences in the transepithelial potentials between NaCl and NaGlu. These originate from differences in paracellular anion permeability but act also on the driving force for Na(+) through apical Na(+) channels. Detection of such an influence on taste depends fundamentally on the preservation of taste bud polarity and on a direct measure of sensory function, such as the response of primary afferents.

Aging↗
PubMed2000

Ovarian and endocrine characteristics during an estrous cycle in Angus, Brahman, and Senepol cows in a subtropical environment.

To determine breed differences in ovarian function and endocrine secretion, daily rectal ultrasonography was conducted on multiparous lactating Angus (temperate Bos taurus; n = 12), Brahman (tropical Bos indicus; n = 12), and Senepol (tropical Bos taurus; n = 12) cows during an estrous cycle in summer. Blood was collected daily to quantify plasma concentrations of FSH, LH, progesterone, estradiol, GH, insulin-like growth factor (IGF)-I, IGF-II, IGF binding proteins (IGFBP), insulin, glucose, and plasma urea nitrogen (PUN). Numbers of small (2 to 5 mm), medium (6 to 8 mm), and large follicles (> or = 9 mm) were greater (P < .05) in Brahman than in Angus and(or) Senepol cows. Length of the estrous cycle (SEM = .6 d) was similar (P > .10) among Senepol (20.4 d), Angus (19.5 d), and Brahman (19.7 d) cows. Senepol cows had greater (P < .05) diameters of the corpus luteum (CL) and a delayed regression of the CL as compared with Angus cows. The secondary surge of FSH (between d 1 and 2; d 0 = estrus) was greater in Angus than Brahman or Senepol cows (breed x day, P < .05). Between d 2 and 14 of the estrous cycle, concentrations of progesterone, LH, IGF-II, and binding activities of IGFBP-3, IGFBP-2, and the 27- to 29-kDa IGFBP in plasma did not differ (P > .10) among breeds. Concentrations of GH, IGF-I, insulin, and PUN were greater (P < .001) and binding activities of the 22-kDa and 20-kDa IGFBP tended (P < .10) to be greater in plasma of Brahman than in Angus or Senepol cows. Plasma glucose concentrations were greater (P < .05) in Senepol than in Brahman or Angus cows. In conclusion, Brahman (Bos indicus) and Senepol cows (tropical Bos taurus) had greater numbers of follicles in all size categories and greater diameter of CL than Angus (temperate Bos taurus) cows. These ovarian differences may be due to changes in the pattern of secretion of FSH, insulin, IGF-I, and GH but not LH, IGF-II, or IGFBP-2 or -3.

Animals↗
PubMed2000

A morbillivirus antibody survey of Atlantic walrus, narwhal and beluga in Canada.

A longitudinal serologic survey was conducted for morbillivirus antibodies in Atlantic walruses (Odobenus rosmarus rosmarus), narwhal (Monodon monoceros), and beluga (Delphinapterus leucas) from the Northwest Territories, Nunavut and the St. Lawrence estuary (Canada). Sixty-five of 131 (50%) walruses sampled between 1984 and 1993 had detectable morbillivirus neutralizing antibodies. Positive walrus were identified from four of five Arctic sampling sites, to as far back as 1984. Prevalence of morbillivirus neutralizing antibodies in walruses from Foxe Basin ranged from a high of 76% (n = 21) in 1993 to a low of 22% (n = 28) in 1984. Limitations in sample acquisition may have produced underestimates for the 1984 data. There are no reports of clinical morbillivirus infection in walruses. Our results are consistent with the hypothesis that a morbillivirus similar or identical to phocine distemper virus (PDV) has circulated among walrus populations of the eastern Canadian Arctic, at least since the early 1980s. No narwhal (n = 79) or beluga (n = 445) from Arctic waters were identified as having antibodies to dolphin morbilivirus (DMV) above the threshold serum dilution of log2 4. Also, none of the beach-cast cetacean carcasses (n = 28) from the Gulf of St. Lawrence and the St. Lawrence estuary were positive for antibodies to DMV. This indicates that Gulf of St. Lawrence, St. Lawrence estuary, and Arctic cetaceans either have not been exposed to DMV or an antigenically related morbillivirus, or are not susceptible to infection.

Animals↗
PubMed1999

Adverse drug reactions and polypharmacy in the elderly in general practice.

OBJECTIVES: The risk of adverse drug reactions (ADRs) increases with the number of drugs used. Most studies refer to potential interactions; the results regarding the severity of occurring and registered ADRs are inconsistent. Therefore, we examined the relevance of drug-induced problems in the elderly in general practice and their association with polypharmacy. DESIGN: Retrospective cross-sectional analysis of prospectively collected data. SETTING: Three family practices participating in the medication and morbidity Registration Network Groningen (RNG). METHODS: From 2185 elderly patients (>64 years) medication and morbidity data were collected over the period of 2 years (1994 and 1995). Polypharmacy was defined as the long-term simultaneous use of two or more drugs. Adverse reactions recognised as such were coded as a separate 'diagnosis' A85. The most risky drug groups and the most prevalent diseases in relation to ADRs were studied. RESULTS: The incidence of ADRs in general practice was 5.7 per 100 elderly patients and the prevalence 6.1 per 100. Moderate polypharmacy was more frequent in the elderly who experienced adverse effects; no other differences in degree of polypharmacy could be found. The elderly who experienced adverse reactions used overall more different drugs (14.4 +/- 7.6, of which 1.5 +/- 1.5 were used long term) than the other elderly patients (8.1 +/- 5.7, of which 1.0 +/- 1.5 were long term). The incidence of ADRs increased non-significantly with the number of drugs used long term. Antibiotics, antihypertensives and non-steroidal anti-inflammatory drugs were mainly responsible for gastrointestinal complaints (nausea, diarrhoea and stomach pain) and rash. In the cases of treating urinary tract infections and sleeping disorders, there was a significantly high risk of ADRs. Slightly more at risk for adverse drug reactions were older patients with coronary heart disease or asthma/chronic obstructive pulmonary disease. CONCLUSION: Most of the ADRs observed in general practice turn out to be rather harmless. This is in agreement with outpatient studies, though not with hospital studies. An increased risk of adverse effects with the number of drugs used simultaneously, as reported in other studies, was not confirmed in our study. This study however is limited to actually registered effects.

Abdominal Pain↗
PubMed1999

Serum levels of matrix metalloproteinase-3 in relation to the development of radiological damage in patients with early rheumatoid arthritis.

OBJECTIVE: To evaluate the significance of serum matrix metalloproteinase-3 (MMP-3) levels in relation to the development of radiological damage (X-ray damage) in early rheumatoid arthritis (RA). METHODS: Serum MMP-3 levels were measured in 46 healthy controls (CTRL), 19 osteoarthritis (OA) and 78 RA patients with joint symptoms for <1 yr at presentation (T0): 48 patients without and 30 with X-ray damage at T0. Serum MMP-3, measured by ELISA, and X-ray damage, scored according to Sharp's method, were assessed at 0, 6, 12 and 24 months. RESULTS: MMP-3 levels in CTRL and OA were low or undetectable with no differences between the groups (P=0.19). Levels in RA were higher than in CTRL (P<0.01). Initial MMP-3 levels in patients with X-ray damage at T0 (n=30) were higher than the levels in patients without any X-ray damage during follow-up (n=19) (P<0.01), but were not different from those in patients who developed X-ray damage during the study (n=29) (P=0.11). In the patients without X-ray damage at T0, there was a significant correlation between MMP-3 at T0 and the total X-ray damage after 6 months (r=0.34, P=0.02) and 12 months (r=0.32, P=0.03). This correlation was almost exclusively determined by joint space narrowing in the Sharp score. CONCLUSION: The serum MMP-3 level seems to be an indicator for the development of radiological damage in patients with early RA and appears to be particularly indicative of cartilage degradation.

Adolescent↗
PubMed1999

A meta-analysis of risk estimates for prostate cancer related to tire and rubber manufacturing operations.

Studies investigating the association between prostate cancer and exposure to the tire and rubber manufacturing environment have reported weak and inconsistent results. A meta-analysis of nine cohort studies that used standard mortality ratios and three case-control studies that used odds ratios was conducted. The pooled results from the nine cohort studies showed a standard mortality ratio of 101 (95% confidence interval [CI] = 93,110), whereas the pooled results from the three case-control studies showed on odds ratio of 1.10 (95% CI = 0.94, 1.29). The standard mortality ratios were converted to odds ratios by dividing by 100. The overall pooled risk estimate from all 12 studies was 1.03 (95% CI = 0.96, 1.11). The conclusion of this meta-analysis is that work exposure in a rubber and tire manufacturing environment does not result in an increased risk of prostate cancer.

Adult↗
PubMed1998

Variation in measurements of grip strength. A study in reflex sympathetic dystrophy patients.

The clinical picture of reflex sympathetic dystrophy (RSD) is characterized by a combination of the triad: autonomic, motor and sensory changes. In this study, the grip strength is measured in 29 upper extremity RSD patients. We used the generalizability theory to assess the extent of the disagreement or differences (errors in measurement) within or between observers and interactions between observer-session and repetition of the measurements. The aims of our study were to determine the different sources of variation in grip strength tests and the smallest detectable differences (SDD) as well as the reliability of upper extremity grip strength tests in RSD patients. The main sources of variation of measurement errors were observer, patient/observer interactions and patient/session/observer interaction and a random source. We found that the generalizability theory is useful for estimating the sources of measurement error. Clinical examinations for muscle strength measurements, as a part of a total clinical examination, for example for a disability payment or worker's compensation in case of RSD patients should be done by more than one observer in more than one session and more than once.

Analysis of Variance↗
PubMed1998

Acid-induced responses in hamster chorda tympani and intracellular pH tracking by taste receptor cells.

HCl- and NaCl-induced hamster chorda tympani nerve responses were recorded during voltage clamp of the lingual receptive field. Voltage perturbations did not influence responses to HCl. In contrast, responses to NaCl were decreased by submucosal-positive and increased by submucosal-negative voltage clamp. Responses to HCl were insensitive to the Na+ channel blockers, amiloride and benzamil, and to methylisobutylamiloride (MIA), an Na+/H+ exchange blocker. Responses to NaCl were unaffected by MIA but were suppressed by benzamil. Microfluorometric and imaging techniques were used to monitor the relationship between external pH (pHo) and the intracellular pH (pHi) of fungiform papilla taste receptor cells (TRCs) following 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein loading. TRC pHi responded rapidly and monotonically to changes in pHo. This response was unaffected by Na+ removal or the presence of amiloride, benzamil, or MIA. The neural records and the data from isolated TRCs suggest that the principal transduction pathway for acid taste in hamster is similar to that in rat. This may involve the monitoring of changes in TRC pHi mediated through amiloride-insensitive H+ transport across TRC membranes. This is an example of cell monitoring of environmental pH through pH tracking, i.e., a linear change in pHi in response to a change in pHo, as has been proposed for carotid bodies. In taste, the H+ transport sites may be concentrated on the basolateral membranes of TRCs and, therefore, are responsive to an attenuated H+ concentration from diffusion of acids across the tight junctions.

Amiloride↗
PubMed1998

Variation in measurements of range of motion: a study in reflex sympathetic dystrophy patients.

OBJECTIVE: To quantify the amount of variation attributed to different sources of variation in measurement results of upper extremity range of motion, and to estimate the smallest detectable difference (SDD) between measurements in reflex sympathetic dystrophy (RSD) patients. DESIGN: Two observers each measured in two sessions the range of motion of several upper extremity joints of RSD patients participating in an outcome study. SETTING: Department of Rehabilitation of a university hospital. SUBJECTS: Twenty-nine upper extremity RSD patients. MAIN OUTCOME MEASURES: The range of motion of forward flexion and external rotation of the shoulder, extension, flexion and supination of the elbow, palmar, dorsiflexion and ulnar, radial deviation of the wrist of affected and nonaffected sides, using a two-armed goniometer and an inclinometer. The measurement results were analysed using an analysis of variance according to the generalizability theory. RESULTS: The results indicate that observer and patient-observer were important sources of variation. The random error was the most important source of variation. Averaged over all ranges of motion the observer contributed 3.9% to the total variation, patient-observer interactions contributed 5.2% and the random error 20.3%. The SDD was smallest for elbow flexion, 7.1 degrees and 9.6 degrees and was largest for external rotation of the shoulder, 24.8 degrees and 28.7 degrees. The SDD was smaller for the nonaffected side as compared to the affected side for the majority of ranges of motion except elbow extension, wrist dorsiflexion, and radial and ulnar deviation. CONCLUSION: Clinically, our results indicate that range-of-motion measurements in RSD patients are subject to considerable variation and indicate that results of medical examinations in order to assess disability on the basis of range-of-motion measurements are subject to the same variation.

Arm↗
PubMed1998

Dental care for the underserved children of Monterey County: meeting the challenge.

With its expansive area, and the special needs of agricultural workers, Monterey County held significant challenges for setting up a children's health clinic. Part of the solution to addressing the county's unmet dental needs was the establishment of the Children's Miracle Network dental center in 1995. But working in the fields leaves little time for travel to appointments, so the dental center expanded to a mobile unit that can go where the need is. Understanding the special needs of one's community is crucial to establishing programs that can successfully address the state's needs for children's dental care.

Adolescent↗
PubMed1997

Effect of Rotablator atherectomy and adjunctive balloon angioplasty on coronary blood flow.

BACKGROUND: The purpose of this study was to assess serial changes in coronary blood flow velocity before and after Rotablator atherectomy and after adjunctive percutaneous transluminal coronary angioplasty (PTCA). Since Rotablator atherectomy results in luminal enlargement by plaque pulverization and distal embolization, improvement in coronary blood flow could be attenuated despite luminal enlargement. METHODS AND RESULTS: Intracoronary Doppler blood flow velocity measurements were obtained with a Doppler Flowire. Basal average peak velocity (bAPV), hyperemic APV (hAPV), diastolic/systolic velocity ratio (DSVR), and coronary flow reserve (CFR) were assessed before intervention, after Rotablator, and after adjunctive PTCA. Complete clinical, angiographic, and Doppler data were obtained in 22 patients. There was a small but significant difference (P = .02) in resting heart rate and mean arterial pressure before and after Rotablator and after adjunctive PTCA. Minimum lumen diameter increased from 0.8 +/- 0.1 to 1.5 +/- 0.2 to 2.0 +/- 0.1 mm (P < .001), corresponding to decreases in diameter stenosis from 72 +/- 3% to 41 +/- 4% to 36 +/- 3% (P < .001). Although bAPV, hAPV, and DSVR increased significantly (P < .001), CFR remained abnormally low in 19 of 22 patients (despite an increase from baseline to post-PTCA). hAPV > 30 cm/s was the best Doppler correlate of angiographic success. CONCLUSIONS: Rotablator atherectomy and adjunctive PTCA significantly improve distal coronary blood flow velocity and DSVR but not CFR. Failure to normalize CFR could be secondary to parallel increases in bAPV and hAPV, "acquired" microvascular disease due to distal microembolization or spasm, and/or angiographically inapparent dissection or residual stenosis. Adjunctive PTCA contributes significantly to the overall physiological benefit of a combined procedure.

Aged↗