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Biomedical subjects

A H Zwinderman

Publications and source records attributed to A H Zwinderman.

At least 199 records · Page 11Linked to original sources
PubMed1996

The mortality of rheumatoid vasculitis compared with rheumatoid arthritis.

OBJECTIVE: To determine whether the mortality of patients with rheumatoid vasculitis (RV) is increased in comparison with that of patients with rheumatoid arthritis (RA). METHODS: The mortality of all RV patients identified in 1980-1992 (n=61) was compared with that of 244 RA controls matched for the year the diagnosis was made in the RV cases. Hazard ratios (HR) of death were calculated with a multivariate survival analysis, adjusting for age, sex, comorbidity, treatment, and parameters of RA severity. RESULTS: The unadjusted risk of death (HR) in RV patients compared with RA controls was 1.65 (95% confidence interval [95% CI] 1.05-2.58). After adjustment for prognostic factors, the HR was reduced to 1.26 (95% CI 0.79-2.01), mainly due to removal of the effects of age and sex. No excess mortality was seen in RV patients with severe organ involvement when compared with RV patients without severe organ involvement, although the former patients were treated more often with cytostatic and immunosuppressive drugs. Infection was the main cause of death in the RV patients, and cardiovascular disease in the RA controls. Vasculitis was reported as the cause of death in only 1 RV patient. CONCLUSION: After allowance for general risk factors such as age and sex, there remains only a slight excess mortality in RV patients compared with RA controls.

Adult↗
PubMed1996

Influence of dopaminergic medication on automatic postural responses and balance impairment in Parkinson's disease.

It is still unclear why balance impairment in Parkinson's disease (PD) often responds insufficiently to dopaminergic medication. We have studied this issue in 23 patients with idiopathic PD and 24 healthy controls. Our specific purposes were (a) to investigate the contribution of abnormal automatic postural responses to balance impairment in PD and (b) to assess the influence of dopaminergic medication on abnormal automatic postural responses and balance impairment. Standing subjects received 4 degrees "toe-up" rotational perturbations of a supporting forceplate. We bilaterally recorded posturally destabilizing medium latency (ML) responses from the stretched gastrocnemius muscles and functionally corrective long latency (LL) responses from the shortened tibialis anterior (TA) muscles. We also assessed changes in the center of foot pressure (CFP) and the center of gravity (COG). All patients were tested in the "off" and "on" phases. All controls were tested and retested after 1 h. During the off phase, we found enlarged ML amplitudes and diminished LL amplitudes in patients, together with a markedly increased posterior displacement of the COG. The abnormal ML and LL responses were partially responsible for the increased body sway in patients because the initial forward (destabilizing) displacement of the CFP was increased, while the subsequent backward displacement of the CFP (a measure of the corrective braking action of LL responses) was delayed. Abnormal late automatic or possibly more voluntary postural corrections also contributed substantially to the increased body sway. During the on phase, ML amplitudes were reduced in patients but remained increased compared with controls. LL amplitudes no longer differed between both groups due to a modest, possibly dopamine-related increase in patients and a simultaneous decrease in controls. The abnormal CFP displacement was only partially improved by dopaminergic medication. The later postural corrections were not improved at all. Consequently, the increased posterior COG displacement was not ameliorated during the on phase. We conclude that (a) a combination of abnormal automatic and perhaps more voluntary postural corrections contributes to increased body sway in PD and (b) dopaminergic medication fails to improve balance impairment in PD because early automatic postural responses are only partially corrected, while later occurring postural corrections are not improved at all. These electrophysiological results support clinical observations and suggest that nondopaminergic lesions play a significant role in the pathophysiology of postural abnormalities in PD.

Adult↗
PubMed1996

Comparison of technetium-99m sestamibi left ventricular wall motion and perfusion studies with thallium-201 perfusion imaging: in search of the combination of variables with the highest accuracy in predicting coronary artery disease.

Measurements of myocardial perfusion and ventricular function are expected to provide additional information in the detection of coronary artery disease (CAD). The purpose of this study was threefold: (1) to determine to what extent technetium-99m sestamibi wall motion yields different information compared with 99mTc-sestamibi and thallium-201 perfusion; (2) to test which information unique to either study is of value in diagnosing CAD; and (3) to assess the combination of variables with the highest diagnostic accuracy. Perfusion and wall motion scores (at rest and during exercise) obtained from visual and quantitative planar 201Tl and 99mTc-sestamibi scintigraphy of 60 patients with suspected CAD were compared with the angiographic results by means of a polytomous logistic regression model and the diagnostic values were compared with one another. All univariate variables were significantly related to the probability of CAD and its extent. Comparative studies revealed a large degree of correlation between 201Tl stress and redistribution variables. The rest 99mTc-sestamibi and wall motion studies contained partially different information. Stepwise logistic regression analysis showed the strongest diagnostic power for the combination of 201Tl visual analysis of the stress images with quantitative redistribution images (sensitivity 93%, specificity 71%). The diagnostic power was similar for all combinations of visual and quantitative analyses of the exercise and redistribution images. The strongest diagnostic power of the 99mTc-sestamibi variables was the score of the diastolic stress image (sensitivity 91%, specificity 79%). Comparable sensitivity and specificity estimates were found when both optimal models were compared. Wall motion studies did not have additional diagnostic power. Although 99mTc-sestamibi wall motion studies, both at rest and during exercise, provide information in addition to the 99mTc-sestamibi or 201Tl myocardial perfusion variables, the information does not enhance the diagnostic power with regard to the prediction of CAD.

Coronary Angiography↗
PubMed1996

Clearance of thallium-201 from the peripheral blood: comparison of immediate and standard thallium-201 reinjection.

As several reinjection procedures have shown encouraging results in terms of imaging, we investigated whether the kinetics of thallium-201 would differ between the standard stress-redistribution-reinjection approach and the stress-immediate reinjection approach. In 53 consecutive patients with undiagnosed chest pain, 75 MBq (2 mCi) 201Tl was injected at maximal exercise. In 26 of these patients (group I), 37 MBq (1 mCi) 201Tl was reinjected immediately after completing the exercise images (the immediate reinjection procedure) and in 27 patients (group II), 37 MBq (1 mCi) 201Tl was reinjected after completing 3-h redistribution images (the standard reinjection procedure). Mean peak 201Tl blood activity after exercise was 17.7+/-12.5 kBq/ml (4.8+/-3.4 mCi/ml) for group I versus 16.4+/-9.2 kBq/ml (4.4+/-2.5 mCi/ml) for group II (NS). The relative increase in 201Tl blood activity after reinjection of half the initial dose [37 MBq (1 mCi)] exceeded 50% of the initial peak in both groups. The relative amount of 201Tl delivered to the myocardium was assessed by the area under the curve after both exercise and reinjection, and was 117%+/-72% for group I and 112%+/-73% for group II (NS). Blood clearance of 201Tl was at least biexponential. Mean early decay constants (lambda 1) after exercise and reinjection were 0.30+/-0.18 min-1 and 0.22+/-0.046 min-1 respectively for group I (T 1/2 2.3 min and 3.2 min respectively, NS), and 0.30+/-0.12 min-1 and 0.24+/-0.07 min-1 respectively for group II (T1/2 2.3 min and 2.9 min respectively, NS). For both procedures no significant differences were found between lambda 1 after exercise and lambda 1 after injection. The mean late clearance (lambda 2) from the blood was 0.032+/-0.056 min-1 and 0.012+/-0.012 min-1 respectively for group I (T1/2 21.6 min and 57.7 min respectively, NS), and 0.036+/-0.030 min-1 and 0.014+/-0.014 min-1 respectively for group II (T1/2 19.3 min and 49.5 min respectively, NS). Also, no significant differences were found between lambda 2 after exercise for both groups and between lambda 2 after reinjection for both groups. We conclude that reinjection of 37 MBq (1 mCi) 201Tl (half the initial dose) results in a relative increase in the initial peak and a relative increase in the amount of 201Tl delivered to the myocardium of more than 50% for both the standard and the immediate reinjection procedure. The clearance of 201Tl from the blood was not influenced by exercise or by the time of reinjection. Based on 201Tl kinetics as measured in the peripheral blood, there is no reason to postpone reinjection until 3-4 h following exercise.

Angina Pectoris↗
PubMed1996

Defect reversibility using thallium-201 reinjection. Comparison of stress-redistribution-reinjection with stress-immediate reinjection.

Immediate poststress thallium-201 reinjection followed by imaging one hour later has been proposed as an alternative reinjection protocol. This procedure is patient-convenient and time-saving as it shortens the investigation time to maximally 2.5 hours. The efficacy of the immediate thallium-201 reinjection protocol was assessed in 305 patients with stress perfusion defects in whom we compared the scintigraphic findings of 210 consecutive patients who underwent the standard thallium-201 stress/redistribution/reinjection protocol (Group I), with 95 consecutive patients who subsequently underwent the thallium-201 stress/immediate reinjection protocol (Group II). In all patients three-view planar images were visually and quantitatively analyzed. In Group I, defect reversibility was observed in 433 of 622 (70%) stress perfusion defects compared to 220 of 320 (69%) segments in Group II (p = NS). With respect to Q-wave related segments, defect reversibility was seen in 102 of 172 (59%) segments in Group I compared to 34 of 63 (54%) in Group II (p = NS). Based on defect reversibility, the diagnosis of myocardial ischemia was made in 184 of 210 (88%) patients Group I compared to 86 of 95 (91%) patients in Group II (p = NS). These findings indicate that immediate thallium-201 reinjection imaging provides at least similar data on defect reversibility as the standard thallium-201 stress/redistribution/reinjection approach. In practical terms, the stress/immediate reinjection approach seems advantageous as it reduces imaging time, enhances patient throughout and can be considered as one comprehensive imaging procedure.

Case-Control Studies↗
PubMed1996

The flare in serum alkaline phosphatase activity after orchiectomy: a valuable negative prognostic index for progression-free survival in prostatic carcinoma.

PURPOSE: We determined whether an early flare in serum alkaline phosphatase activity after orchiectomy was of prognostic value for progression-free survival in patients with advanced prostatic carcinoma. MATERIALS AND METHODS: A retrospective analysis of a data base from a Dutch multicenter study on prostatic carcinoma was done to determine the prognostic value of a flare in alkaline phosphatase activity after orchiectomy in 112 patients with metastatic (75%) or locally advanced (25%) disease. Cox's proportional hazards models and Kaplan-Meier survival curves were used. RESULTS: Of the patients 50% had initially increased alkaline phosphatase levels and a flare in activity was demonstrated in 87% 2 to 4 weeks after orchiectomy. The prostate specific antigen nadir (cutoff 4 ng./ml.) 6 months after orchiectomy was of significant prognostic value for progression-free survival. A flare in alkaline phosphatase activity after orchiectomy demonstrated an early significant prognostic value for progression-free survival, independent of the serum alkaline phosphatase activity. CONCLUSIONS: The simplicity, ready availability and cost-effectiveness of serum alkaline phosphatase activity as a prognostic index render it attractive to the clinician, particularly early in the course of prostatic carcinoma. Measuring the flare in alkaline phosphatase activity within 1 month of orchiectomy may permit early identification of patients in whom the disease is likely to progress rapidly and who would potentially benefit from aggressive treatment.

Aged↗
PubMed1996

Tumor-associated eosinophilic infiltrate of cervical cancer is indicative for a less effective immune response.

The local inflammatory tumor infiltrate related to cervical carcinoma has been shown to consist mainly of T lymphocytes and macrophages. In 5% to 40% of the cases, eosinophilic granulocytes from a major part of the tumor-infiltrating cells. The presence of a high percentage of eosinophilic granulocytes in the infiltrate might reflect a less effective antitumor response, resulting in a worse overall survival. In the present study, histological slides from 83 patients who had been treated for cervical squamous carcinoma were reviewed. Special emphasis was put on the presence of eosinophils in the tumor infiltrate and correlated with clinical outcome as a parameter of the strength of the host-antitumor response. Multivariate analysis showed that the presence of a large amount of eosinophils among the infiltrate was an independent parameter, predicting a worse overall survival in patients with tumor-negative lymph nodes and tumor-negative resection margins (n = 61). The presence of eosinophilic granulocytes might represent a less appropriate immune response based on a disturbed equilibrium between Th-1- and Th-2-mediated immune response.

Adult↗
PubMed1996

A randomized clinical trial of in-patient multidisciplinary treatment versus routine out-patient care in active rheumatoid arthritis.

The aim of the present study was to compare the effects of in-patient multidisciplinary treatment with standard out-patient care in patients with active rheumatoid arthritis (RA). Eighty patients with active RA were randomized to receive 11 days of in-patient multidisciplinary treatment followed by standard out-patient care (n = 39), or to standard out-patient care only (n = 41). Patients were assessed at baseline, and after 2, 4, 12 and 52 weeks. In the in-patients, the improvement in variables of disease activity (weeks 2 and 4) and emotional status (weeks 4 and 12) was greater when compared with the out-patients (P < 0.05). The improvement in laboratory and functional measures did not differ between the groups. In the in-patient group, the percentage of patients responding to the American College of Rheumatology criteria for improvement was significantly greater at any time point during follow-up than in the out-patient group. A short period of in-patient multidisciplinary treatment for active RA has a direct beneficial effect on disease activity and emotional status with the favourable effect on disease activity remaining after 52 weeks.

Adolescent↗
PubMed1996

Cortical excitability and response variability of transcranial magnetic stimulation.

The magnetic evoked potential (MEP) following transcranial magnetic stimulation is subject to several sources of variability. In this study, relationships between stimulus intensity and MEP latency, amplitude, duration, and area of the hypothenar muscles were assessed in 12 right- and 14 left-handed subjects. Effects of handedness, coil orientation, intensity of stimulation, and intersubject variability on these relationships were analyzed. The intraindividual variability was analyzed as the standard deviation (SD) and the coefficient of variation (CV) of four trials. The mean response threshold was significantly lower (p < 0.0001) for preferential stimulation (32%) than for nonpreferential stimulation (45%). With increasing stimulus intensities, MEP amplitudes still increased at 100% intensity in some subjects while in others the stimulus response-relations saturated. MEP amplitudes at an intensity of 20% above threshold ranged between 6 and 100% of MEP amplitude at maximum intensity. Differences between dominant and non-dominant hands were not seen, regardless of handedness. The SD of latency, amplitude, duration, or area depended on stimulus intensity. The CV however, was influenced by the intensity of stimulation: The CV for amplitude decreased from 46% at threshold to 10% at higher intensities. The variability of the MEP amplitude is only related to stimulus intensity when it is expressed in relation to it but not when it is expressed in absolute terms. The stimulus-response relation offers a more extensive measure of cortical excitability than the use of thresholds alone for the measurement of cortical excitability. The question can be raised whether high intensities should be used for clinical testing rather than threshold-related intensities.

Adult↗
PubMed1996

Comparison of adenosine and high-dose dipyridamole both combined with low-level exercise stress for 99Tcm-MIBI SPET myocardial perfusion imaging.

Intravenously administered adenosine and high-dose dipyridamole, both combined with low-level exercise stress, were compared in a head-to-head fashion using 99Tcm-methoxyisobutyl isonitrile (99Tcm-MIBI) single photo emission tomography (SPET) myocardial perfusion imaging. Thirty-nine consecutive patients who had undergone coronary arteriography underwent 99Tcm-MIBI (740 Mbq) SPET after dipyridamole (0.84 mg kg-1) and after adenosine (0.84 mg kg-1), both combined with low-level exercise (30 W load), and under resting conditions. Our results demonstrate that adenosine and dipyridamole combined with exercise have comparable haemodynamic effects, with a low incidence of side-effects. The time of recovery from the stress protocol was not significantly different: adenosine, 5.7 +/- 3.9 min; dipyridamole, 6.6 +/- 4.9 min. However, aminophylline was significantly (P < 0.05) more often administered to reverse side-effects using the dipyridamole protocol (36% of patients) compared with the adenosine protocol (8% of patients). The results of 99Tcm-MIBI SPET imaging were highly concordant and demonstrated a high diagnostic accuracy for identifying coronary artery disease (CAD). The sensitivity was 90% (95% confidence intervals 79-100%) with adenosine SPET and 93% (95% confidence intervals 84-100%) with dipyridamole SPET for identifying patients with CAD (i.e. luminal stenosis > 50%); their specificities were both 100% (95% confidence intervals 66-100%). The sensitivity of identifying angiographically diseased vessels was 81% (95% confidence intervals 70-92%) using adenosine SPET and 85% (95% confidence intervals 75-95%) using dipyridamole; the specificity for both stress modalities was 94% (95% confidence intervals 89-100%). The combination of exercise with adenosine and high-dose dipyridamole appears to be a feasible and safe method to alleviate some of the undesirable A1-receptor-mediated side-effects of adenosine. The choice of the pharmacological stress will depend on local expertise and availability.

Adenosine↗
PubMed1996

Head-to-head comparison of 201Tl rest-redistribution scintigraphy and stress-immediate reinjection scintigraphy in the detection of myocardial viability.

Reinjection imaging with thallium-201 (201Tl) provides a reliable method of identifying viable myocardium. Reinjection of 201Tl immediately after completing the stress images followed by imaging 1 h after reinjection shortens the examination time to a maximum of 2.5 h and provides an alternative imaging approach in patients with coronary artery disease. In this study, we investigated whether immediate 201Tl reinjection imaging provides adequate information on myocardial viability compared with separate-day 201Tl rest or rest-redistribution imaging. In 23 patients with anterior or anteroseptal wall infarction first documented more than 3 months previously, we performed 201Tl stress-immediate reinjection, separate-day 201Tl rest imaging and rest-stress radionuclide angiography. In 13 patients, 201Tl rest scintigraphy was followed by redistribution imaging 3 h later. On the three-view planar 201Tl images, eight myocardial segments were analysed visually and quantitatively. Stress 201Tl images were compared with 201Tl reinjection images, 201Tl rest images and 201Tl 3-h redistribution images after rest injection. When comparing the stress images both with the immediate reinjection images and the rest images, concordant scintigraphic classification was found in 181 of 184 myocardial segments (kappa = 0.97). Comparing the stress images both with the immediate reinjection images and with the 3-h redistribution images following 201Tl injection at rest, concordant scintigraphic classification was found in 102 of 104 myocardial segments (kappa = 0.97). In 16 of 23 (70%) patients, 201Tl stress-immediate reinjection scintigraphy and radionuclide angiography provided concordant information on myocardial viability. In 6 (26%) patients, we observed a function-perfusion mismatch (i.e. 201Tl uptake in dyskinetic/adyskinetic regions) indicative of jeopardized but viable myocardium, demonstrating the additional value of 201Tl as a marker of viability. We conclude that stress-immediate 201Tl reinjection images provide information on myocardial viability and ischaemia in patients with previous myocardial infarction in addition to that obtained regarding wall motion abnormalities as assessed by rest-stress radionuclide angiography.

Adult↗
PubMed1996

Quantitative analysis of defect reversibility after immediate and standard 201Tl reinjection.

Immediate reinjection of 201Tl after exercise imaging has been proposed as a time-saving approach for the accurate distinction between ischaemic and scarred myocardium. However, with this procedure, defect reversibility may be underestimated due to the high level of residual 201Tl activity in normally perfused myocardium at the time of reinjection. The aim of this study was to determine whether the detection of defect reversibility is hampered by a shortening of the time interval between exercise and reinjection. In 53 patients, 201Tl was injected, at the point of maximal exercise. In 26 patients, 201Tl was reinjected immediately after exercise imaging (Group I); in 27 patients, 201Tl was reinjected after 3 h redistribution imaging (Group II). In all patients (424 myocardial segments), three-view planar images were analysed quantitatively. Changes in myocardial activity after 3 h redistribution and reinjection were compared with the post-exercise images. In normal segments, the relative change in 201Tl activity after reinjection was 8.8 +/- 19.9% in Group I and -19.7 +/- 19.5% in Group II (P < 0.05). In Group I, persistent defects showed a relative change of 14.3 +/- 25.1% and reversible defects a relative change of 36.3 +/- 41.6% (P < 0.05). In Group II, persistent defects showed a relative change of -15.1 +/- 18.3% and reversible defects a relative change of 2.4 +/- 25.2% (P < 0.05). Our results indicate that shortening the time interval between exercise and reinjection has no effect on the detection of ischaemia.

Adult↗
PubMed1996

Factors associated with the development of vasculitis in rheumatoid arthritis: results of a case-control study.

OBJECTIVE: To investigate those characteristics of patients with rheumatoid arthritis (RA) that are associated with the development of rheumatoid vasculitis (RV). METHODS: Demographic and clinical data of 69 patients who had been diagnosed as having RV were compared with those of 138 contemporaneous control patients with RA who were not suspected to have vasculitis. Vasculitis was confirmed histologically in 96% of the subjects with RV. RESULTS: Variables associated with the development of RV were: 1) male gender, presence of increased serum concentrations of rheumatoid factor, joint erosions, subcutaneous nodules, number of disease modifying antirheumatic drugs previously prescribed, treatment (ever) with D-penicillamine or azathioprine; 2) presence of nail fold lesions and any other extrarticular feature one year before the time of diagnosis of RV; 3) treatment with corticosteroids at the time of diagnosis of RV. CONCLUSIONS: The development of RV is associated with male gender, extra-articular features, and a severe course of RA as indicated by the presence of joint destruction and need for intensive treatment with antirheumatic drugs. The strongest association was found with the presence of increased concentrations of rheumatoid factor.

Adrenal Cortex Hormones↗
PubMed1996

Evidence for a synergistic effect of calcium channel blockers with lipid-lowering therapy in retarding progression of coronary atherosclerosis in symptomatic patients with normal to moderately raised cholesterol levels. The REGRESS Study Group.

To date, lipid-lowering therapy appears to be the most effective medical intervention to retard progression of coronary atherosclerosis. In spite of promising experimental results, clinical trials completed so far have failed to demonstrate that calcium channel blockers (CCBs) alone influence the evolution of established coronary atherosclerosis. To assess whether the two therapies may have an additive or synergistic beneficial effect on human atherosclerosis, we reviewed in this regard the data of the angiographic Regression Growth Evaluation Statin Study (REGRESS) trial. REGRESS was designed to determine the effect of lipid-lowering therapy with pravastatin in symptomatic patients with normal to moderately raised cholesterol levels. Angiographically, with respect to the minimum obstruction diameter, in the pravastatin group, patients had on average 0.05 mm (95% confidence interval [CI]: 0.01-0.09) less progression if cotreated with CCBs compared with no CCB treatment, whereas in the placebo (no pravastatin) group, no effect of CCB treatment was observed (interaction test for differential effect of CCB treatment in patients with pravastatin compared with patients receiving placebo: P=.0016). With respect to the mean segment diameter, similar although not significant (P=.33) results were found. With respect to new lesion formation, in the pravastatin group, there were 50% (CI: 25-83) fewer patients with new angiographic lesions if cotreated with CCBs compared with no CCB cotreatment, whereas in the placebo (no pravastatin) group, no significant effect of CCB treatment was observed (interaction test: P=.0026). No beneficial effects of CCB treatment on clinical events were observed. Although the REGRESS trial was not designed to evaluate combination therapy, the results suggest strongly that addition of CCBs to 3-hydroxy-3-methyl-glutaryl-coenzyme reductase inhibitor therapy (pravastatin) acts synergistically in retarding the progression of established coronary atherosclerosis.

Aged↗
PubMed1996

Lung sounds during allergen-induced asthmatic responses in patients with asthma.

We postulated that the distinct pathophysiologic mechanisms of airway narrowing during the early (EAR) and the late (LAR) asthmatic responses to inhaled allergens are reflected by the generation or transmission of lung sounds in asthma. Therefore, we measured FEV1 and recorded lung sounds in eight mildly asthmatic subjects before a standardized allergen challenge (PRE), during the EAR, during the recovery phase at 2 h (MID), during the LAR at 7 h, and after inhalation of a bronchodilator (POST). The recordings were made during flow- and volume-standardized quiet breathing, and during maximal forced breathing maneuvers. Airflow-dependent power spectra were analyzed for lung sound intensity (LSI), quartile power points (Q25, Q50, Q75), and extent of wheezing (W). These sound characteristics were compared among the various stages of the challenge in the presence (EAR, LAR) and absence (PRE, MID, POST) of acute airway obstruction using ANOVA. LSI, Q25 - Q75, and W were all elevated during airway obstruction. When matched for percent fall in FEV1, during the EAR and the LAR (mean +/- SD: 26.7 +/- 4.0, and 28.9 +/- 5.7, respectively; p = 0.385), the increase in Q25, and Q50 with airflow during quiet expiration, as well as the extent of wheezing, were higher during the LAR than during the EAR (p < or = 0.042 and p < or = 0.012, respectively). At similar levels of FEV1 (p > or = 0.156), LSI on expiration was higher at POST than at PRE or MID (p < or = 0.067), whereas Q25 (p < or = 0.047) and Q50 (p < or = 0.064) were lower at POST than at PRE. During forced expiration W was higher at MID and POST than at PRE (p < or = 0.014). We conclude that LSI, frequency content, and the extent of wheezing vary during the subsequent stages of allergen-induced bronchoconstriction in asthma despite matched values of FEV1. This suggests that airflow-standardized phonopneumography is a sensitive method for detecting differences in the pathophysiology of airway narrowing in asthma.

Acoustics↗
PubMed1996

Determinants of hand function in patients with rheumatoid arthritis.

OBJECTIVE: To investigate which clinical variables contribute to the function of the hand in activities of daily living (ADL) in patients with rheumatoid arthritis (RA). METHODS: In 50 patients with RA hand function in ADL was assessed by (1) the dexterity items of the Arthritis Impact Measurement Scales (AIMS), (2) direct observation of the same items by an occupational therapist, and (3) the Jebsen hand function test. A combined hand function factor was constructed by principal component analysis of the 3 hand function measures. Further assessments included measurements of muscle strength, deformity and destruction, range of motion, and local arthritis activity. After bivariate analyses, variables that correlated significantly with the measures of hand function were entered into stepwise multiple regression analyses. RESULTS: The variables having a significant correlation with most of the hand function measures were: pinch and grip strength, patient's assessment of pain and stiffness of the hands, flexion of the thumb and fingers, range of motion of the wrist, alignment of the metacarpophalangeal (MCP) joints, swan neck and Z deformities, and the Larsen erosion score. 78% of the variance of the combined hand function factor could be explained by pinch strength, stiffness of the hands, and the presence of Z deformity and ulnar deviation. CONCLUSION: Pinch and grip strength should be carefully considered in setting goals for conservative or surgical treatment of the rheumatoid hand. In addition, reported stiffness of the hands, malalignment of the MCP joints, and flexion and deformity of the thumb were the most consistent indicators of impaired hand function.

Activities of Daily Living↗
PubMed1996

Stress-reinjection 201Tl scintigraphy without redistribution imaging: prediction of the effect of coronary artery bypass grafting on regional myocardial 201Tl uptake.

Reinjection of thallium-201 (201Tl) improves the detection of myocardial ischaemia in approximately 50% of irreversible defects present on 3 h redistribution images. Additional reinjection studies, however, may limit the capacity of the nuclear laboratory and they are not patient-friendly Previous studies have suggested that only severe persistent defects with less than 50% of maximal 201Tl uptake are irreversibly damaged, with little chance of recovery following coronary artery bypass grafting (CABG). We examined the ability of a modified stress-reinjection protocol without redistribution imaging to predict subsequent improvement in myocardial perfusion post-CABG. Thirty-seven patients underwent quantitative planar stress/3 h reinjection 201Tl scintigraphy before and after uncomplicated CABG. After stress, segments were classified as normal (> or = 75% maximum 201Tl uptake), moderate defect (50-75%) or severe defect (< 50%). After reinjection, they were classified as completely normalizing (> or = 75%), partially improving moderate defect (increase > or = 10% but < 75%), partially improving severe defect (increase > or = 10% but < 50%), persistent moderate defect (< 10% increase) or persistent severe defect (< 50% initial uptake with < 10% increase). Scintigraphic classification was compared with left ventricular wall motion and post-operative classification. Of 336 initial stress defects, 264 (79%) were moderate defects and 72 (21%) were severe defects. After reinjection, 146 (55%) moderate defects normalized, 25 (9%) improved partially and 93 (35%) persisted. Nineteen (26%) severe defects normalized, 33 (46%) improved to become moderate defects, 7 (10%) improved only slightly and 13 (18%) persisted. Post-CABG, 201T1 uptake was normal in 123 of 146 (84%) completely normalizing moderate defects, 15 of 25 (60%) partially improving moderate defects, 53 of 93 (57%) persistent moderate defects, 11 of 19 (58%) completely normalizing severe defects and 13 of 33 (39%) partially improving moderate defects. None of the partially improving severe defects or persistent severe defects normalized. The sensitivity and specificity of detection of viability with pre-CABG stress-injection scintigraphy were 66% and 72% respectively, with pre-CABG wall motion 80% and 40% respectively, whereas in combination they resulted in a sensitivity and specificity of 94% and 70% respectively. We conclude that stress/3 h reinjection without redistribution imaging is a clinically feasible method for predicting myocardial 201T1 uptake post-CABG. The severity of defects and the pattern of change of uptake after stress-injection are related to the likelihood of normal 201T1 uptake post-CABG. Severe defects after reinjection are very unlikely to recover.

Adult↗