Biomedical subjects

A Duhamel

Publications and source records attributed to A Duhamel.

At least 19 recordsLinked to original sources

PubMed2006

Improvement of gait by chronic, high doses of methylphenidate in patients with advanced Parkinson's disease.

BACKGROUND: Therapeutic management of gait disorders in patients with advanced Parkinson's disease (PD) can sometimes be disappointing, since dopaminergic drug treatments and subthalamic nucleus (STN) stimulation are more effective for limb-related parkinsonian signs than for gait disorders. Gait disorders could also be partly related to norepinephrine system impairment, and the pharmacological modulation of both dopamine and norepinephrine pathways could potentially improve the symptomatology. AIM: To assess the clinical value of chronic, high doses of methylphenidate (MPD) in patients with PD having gait disorders, despite their use of optimal dopaminergic doses and STN stimulation parameters. METHODS: Efficacy was blindly assessed on video for 17 patients in the absence of L-dopa and again after acute administration of the drug, both before and after a 3-month course of MPD, using a Stand-Walk-Sit (SWS) Test, the Tinetti Scale, the Unified Parkinson's Disease Rating Scale (UPDRS) part III score and the Dyskinesia Rating Scale. RESULTS: An improvement was observed in the number of steps and time in the SWS Test, the number of freezing episodes, the Tinetti Scale score and the UPDRS part III score in the absence of L-dopa after 3 months of taking MPD. The L-dopa-induced improvement in these various scores was also stronger after the 3-month course of MPD than before. The Epworth Sleepiness Scale score fell dramatically in all patients. No significant induction of adverse effects was found. INTERPRETATION: Chronic, high doses of MPD improved gait and motor symptoms in the absence of L-dopa and increased the intensity of response of these symptoms to L-dopa in a population with advanced PD.

Aged↗

PubMed2006

Vigilance troubles in Parkinson's disease: a subjective and objective polysomnographic study.

BACKGROUND AND PURPOSE: To assess the prevalence of vigilance disorders in Parkinson's disease patients, relate the observed phenomena to potential causes and confirm these troubles with polysomnographic analysis. PATIENTS AND METHODS: A questionnaire was used to gather information on demographic data, previous and current treatments, disease characteristics, sleep and vigilance troubles. Somnolence was measured using the Epworth Sleepiness Scale (ESS). Nocturnal polysomnography (PSG) and multiple sleep latency tests (MSLT) were performed for a sample of parkinsonian patients. RESULTS: Two hundred twenty-two parkinsonian patients completed the questionnaire, and 36 patients had objective analyses. Of the patients, 43.2% had an ESS score >10, and 28.4% reported somnolence in the hour after taking dopaminergic drugs, whereas 6.8% reported unintended sleep episodes. In view of questionnaire data, these vigilance disorders may be partly explained not only by the impact of nocturnal sleep disorders (e.g. sleep apnea syndromes) but also by dopaminergic therapy (especially with dopaminergic agonists). With PSG and MSLT results, we have shown a significant correlation between mean sleep latency and ESS score. Patients with unintended sleep episodes have severe sleepiness in MSLT compared with others patients. CONCLUSIONS: Vigilance disorders are frequently observed in Parkinson's disease. We recommend informing patients of the risk of occurrence of such conditions, notably for patients with unintended sleep episodes and with sleepiness in the hour after taking dopaminergic drugs.

Aged↗

PubMed2006

Low-dose ECG-gated 64-slices helical CT angiography of the chest: evaluation of image quality in 105 patients.

The purpose of this study was to evaluate image quality of low-dose electrocardiogram (ECG)-gated multislice helical computed tomography (CT) angiograms of the chest. One hundred and five consecutive patients with a regular sinus rhythm (72 men; 33 women) underwent ECG-gated CT angiographic examination of the chest without administration of beta blockers using the following parameters: (a) collimation 32 x 0.6 mm with z-flying focal spot for the acquisition of 64 overlapping 0.6-mm slices, rotation time 0.33 s, pitch 0.3; (b) 120 kV, 200 mAs; (c) use of two dose modulation systems, including adjustment of the mAs setting to the patient's size and anatomical shape and an ECG-controlled tube current. Subjective and objective image quality was evaluated by two radiologists in consensus on 3-mm-thick scans reconstructed at 55% of the response rate (RR) interval. The population and protocol characteristics included: (a) a mean [+/-standard deviation (SD)] body mass index (BMI) of 24.47 (+/-4.64); (b) a mean (+/-SD) heart rate of 72.04 (+/-15.76) bpm; (c) a mean (+/-SD) scanning time of 18.3 (+/-2.73) s; (d) a mean (+/-SD) dose-length product (DLP) value of 260.57 (+/-83.67) mGy/cm; (e) an estimated average effective dose of 4.95 (+/-1.59) mSv. Subjective noise was depicted in a total of nine examinations (8.5%), always rated as mild. Objective noise was assessed by measuring the standard deviation of pixel values in a homogeneous region of interest within the trachea and descending aorta; SD was 15.91 HU in the trachea and 22.16 HU in the descending aorta, with no significant difference in the mean value of the standard deviations between the four categories of BMI except for obese patients, who had a higher mean SD within the aorta. Interpolation artefacts were depicted in 22 patients, with a mean heart rate significantly lower than that of patients without interpolation artifacts, rated as mild in 11 patients and severe in 11 patients. The severity of interpolation artefacts was significantly linked to a low heart rate in affected patients. The overall image quality of CT scans was rated as diagnostic in 94 patients (89.5%) while 11 examinations (10.5%) were found to be partially nondiagnostic owing to the cyclic presence of severe interpolation artefacts, which can be compensated for by additional reconstructions at a different temporal window. In these cases, interpolation artefacts could have been avoided by reducing the pitch from 0.3 to 0.2 at the expense of increased patient dose. Low-dose ECG-gated CT angiograms of the chest can be obtained in routine clinical practice with 64-slice CT technology without altering the diagnostic value of CT scans.

Adolescent↗

PubMed2006

Factors associated with perceived exertion and estimated time limit at lactate threshold.

The purpose was to identify the most predictive parameters for perceived exertion and estimated time limit responses at the velocity corresponding to the lactate concentration threshold. The former scale concerns the subject's current status (how hard he feels the exercise currently is) whereas the latter scale deals with a subjective prediction of how long the current exercise level can be maintained. Multiple regression equations were developed among physiological, psychological, nutritional, and individual parameters (subjects' characteristics and performances) as independent variables, and perceived exertion or estimated time limit as dependent variables. Independent variables were collected before or during an incremental running field test. 94 regional to national level athletes (47 endurance-trained runners, 11 sprinters, and 36 handball players) participated. Multiple stepwise regression showed that Rating of Perceived Exertion and Estimated Time Limit at the lactate threshold were mainly mediated by factors relative to the performance expressed in percentage of the maximal aerobic velocity. Secondary factors which contribute significantly as perceptual predictors were related to various classes of factors except for psychological factors.

Adaptation, Psychological↗

PubMed2006

[The effect of an endothelin receptor antagonist in Eisenmenger syndrome: a single-center experience of 11 patients].

The Eisenmenger syndrome is a complication of congenital heart disease with significant left-to-right shunts, such as large ventricular septal defects, and corresponds to fixed pulmonary hypertension with shunt reversal. Bosentan, an inhibitor of endothelin A and B receptors, is a new molecule previously validated in the treatment of primary pulmonary hypertension. The authors report their monocentric experience of bosentan in 11 consecutive patients with the Eisenmenger syndrome treated for at least one year. This retrospective study comprised 7 females and 4 males with an average age of 34 years (range 17 to 51 years). The underlying lesion was ventricular septal defect (n = 4), atrial septal defect (n = 3), pulmonary atresia with septal defect (n = 4 of which 2 were treated palliatively). Before treatment, the patients were classified according to the NHYA functional class (I, II, IIIa and IIIb, IV or, respectively from 1 to 5) with a distribution in this series between Classes IIIa and IV (average 3.81 +/- 0.75) and from 3 to 10 on Borg's dyspnoea scale (average 6.54 +/- 2.29). The ambient oxygen saturation (SaO2) at rest was, on average 77 +/- 9%, the haemoglobin concentration 16.6 +/- 2.4 g/dl; hepatic transaminase levels were normal. The 6 minute walk test before treatment was 216 +/- 111 m with marked desaturation on exercise (49 +/- 18%). With Bosentan, patients were globally much better clinically with a decrease in dyspnoea, improvement in NHYA class and increased 6 minute walking perimeter. Improvement in NYHA class was observed from 3 months' treatment (3.0 +/- 0.8, p = 0.0002) and was sustained to one year (2.54 +/- 0.7, p< 0.001). An improvement of dyspnoea on Borg's scale was observed from the second month's treatment (5.56 +/- 1.65, p = 0.0201) and persisted throughout follow up to one year (3.81 +/- 1.32, p < 0.0001). Similarly, the 6 minute walking perimeter increased from the first control at 6 months (323 +/- 82 m, p < 0.0001) and at one year (322 +/- 62 m, p <0.0004). Finally, although a significant increase in SaO2 was observed at 6 months (p = 0.0032), this was hardly significant at one year (82 +/- 10 %, p = 0.0512). Transaminase levels did not rise significantly at the follow up visits (p = ns) and the haemoglobin concentration was unchanged. No patient died during the study period. This study showed a clear functional improvement in patients with Eisenmenger's syndrome treated with bosentan. The drug was well tolerated clinically with few adverse effects and a good safety margin of usage.

Adolescent↗

PubMed2006

Impact of CPOE on mortality rates--contradictory findings, important messages.

OBJECTIVE: To analyze the seemingly contradictory results of the Han study (Pediatrics 2005) and the Del Beccaro study (Pediatrics 2006), both analyzing the effect of CPOE systems on mortality rates in pediatric intensive care settings. METHODS: Seven CPOE system experts from the United States and Europe comment on these papers. RESULTS: The two studies are not contradictory, but almost non-comparable due to differences in design and implementation. They demonstrate the range of outcomes that can be obtained from introducing informatics applications in complex health care settings. Implementing informatics applications is a sociotechnical activity, which often depends more on the organizational context than on a specific technology. As health informaticians, we must not only learn from failures, but also avoid both uncritical scepticism that may arise from drawing overly general conclusions from one negative trial, as much as uncritical optimism from limited successful ones. CONCLUSION: The commentaries emphasize the need to promote systematic studies for assessing the socio-technical factors that influence the introduction of increasingly sophisticated informatics applications within complex organizations. The emergence of evidence-based health informatics will be based both on evaluation guidelines and implementation guidelines, both of which increase the chances of successful implementation. In addition, well-educated health informaticians are needed to manage and guide the implementation processes.

Europe↗

PubMed2005

Anti-Saccharomyces cerevisiae antibodies in twins with inflammatory bowel disease.

BACKGROUND AND AIMS: An increased occurrence of anti-Saccharomyces cerevisiae antibodies (ASCA) is reported in unaffected members of families with Crohn's disease. Whether ASCA is a familial trait due to genetic factors or is caused by exposure to environmental factors is unknown. To assess the genetic influence of ASCA we studied its occurrence in a twin population. PATIENTS AND METHODS: ASCA were analysed in 98 twin pairs with inflammatory bowel disease and were related to clinical phenotype and CARD15/NOD2 genotype. RESULTS: ASCA were more common in Crohn's disease than in ulcerative colitis (40/70 (57%) twins v 5/43 (12%) twins). Associations with ileal Crohn's disease, stricturing/penetrating behaviour, and young age, but not CARD15/NOD2 were confirmed. ASCA were found in 1/20 (5%) healthy siblings in discordant monozygotic pairs with Crohn's disease compared with 7/27 (26%) in discordant dizygotic pairs. Using the intraclass correlation coefficient (ICC), no agreement in ASCA titres was observed in discordant twin pairs with Crohn's disease, in monozygotic (ICC = -0.02) or dizygotic (ICC = -0.26) pairs. In contrast, strong agreement was seen within concordant monozygotic twin pairs with Crohn's disease (ICC = 0.76). CONCLUSIONS: These findings question the concept of ASCA as a marker of genetic susceptibility for Crohn's disease. The agreement in ASCA titres within concordant monozygotic twin pairs with Crohn's disease, suggests that the level of increase is genetically determined. We propose that ASCA are a marker of a response to an environmental antigen and that a specific gene(s) other than CARD15/NOD2 determines the level of response and perhaps also specific phenotypic characteristics.

Adult↗

PubMed2005

Influence of social class on time trends in BMI distribution in 5-year-old French children from 1989 to 1999.

AIMS: To assess the prevalence of obesity and changes in body mass index (BMI) distribution between 1989 and 1999 in 5-y-old children, and to study the influence of parental socioeconomic status on these parameters. METHODS: Two cohorts of children in the final year of nursery school (in the city of Lille, France) were enrolled in 1989 (705 children: mean age=5.6+/-0.4 y) and 1999 (1258 children: mean age=5.6+/-0.5 y). Weight and height were measured, and data about parental occupation were collected during a school medical examination. International Obesity Task Force cutoff points were used to define overweight and obesity. Parental occupation was classified into four categories. RESULTS: The prevalence of obesity increased from 1.8 to 4.9%, and the prevalence of overweight rose from 9.6 to 16.9%. Mean-difference plots allowed qualitative comparisons of the BMI distribution between the surveys: for children from the highest social classes, there was no change in BMI; for children from intermediate classes, there was a up-shift only in the upper part of the distribution with the heaviest children becoming heavier still; finally, for children from the lowest class, there was an increase in BMI across the entire population. CONCLUSIONS: This study of the changes in BMI distribution gives greater insight into the 'obesity epidemic'. Our results show the influence of an interaction between genetic and environmental factors. The increase in BMI in the upper part of the distribution suggests that this is a population with a high degree of susceptibility, whereas the increase in BMI across the whole population in the lowest social class suggests a strong influence of the environment on this group and thus the necessity of appropriate, preventive measures.

Age Distribution↗

PubMed2004

Treatment of progressive forms of multiple sclerosis by cyclophosphamide: a cohort study of 490 patients.

There are no generally effective disease-modifying drugs for progressive forms of multiple sclerosis (MS). Some MS centres use cyclophosphamide (CYC) in secondary progressive (SP) forms of MS, especially after interferon beta-1b (INFbeta-1b) treatment failure. Moreover, there are currently no approved drugs for primary progressive (PP) MS. Using the collected data of patients with progressive MS, we studied clinical patterns that predicted a good response to CYC treatment. Secondly, we compared the therapeutic response of SPMS and PPMS patients to the treatment. Data from 490 MS patients were collected. All patients presented an SP (n = 362) or PP (n = 128) form of the disease and 476 had been treated for at least one year with a monthly pulse of CYC associated with methylprednisolone (MP). CYC treatment was justified because of at least a 1-point worsening on the Expanded Disability Status Scale (EDSS) during the previous year. The EDSS score was assessed at baseline and after 6 months (M6) and 12 months (M12) of treatment. After 12 months of CYC treatment, 78.6% of SPMS and 73.5% of PPMS patients had stabilised or had an improved EDSS score. Response to CYC was not significantly different in the two progressive forms of MS. Twenty-two patients presented noticeable drug side effects, one of whom withdrew from the treatment due to intolerance. Patients with an improved EDSS at M12 had a shorter mean progressive time course (5.1 years) than patients who stabilised or worsened (7.1 years) (p = 0.02). We also observed that poor responders at M6 were also poor responders at M12 (p < 0.001). This large cohort study showed that CYC treatment was well tolerated and suggested that a better response occurred in cases with a short progressive time course. We did not find any difference in treatment response between the two progressive forms of MS. To date, no treatment is approved for PPMS and we therefore propose a trial to test the use of CYC treatment early in the course of the disease in PPMS patients with disability progression.

Adult↗

PubMed2004

Statistical tools for clinical gait analysis.

Gait analysis studies involve continuous curves of data measured over a gait cycle. Curve analysis and interpretation require adequate statistical methods. Three principal problems may be encountered in clinical practice: (i) the reliability of gait curves for a given patient, (ii) classifying a new subject as belonging to a given population or not and (iii) comparison of two populations (independent or paired). This paper presents three statistical tools for solving these problems: (i) intra-class correlation coefficients, (ii) confidence bands for a population (iii) a combination of analysis of variance and confidence bands for the difference between the means and shows how they can be used in clinical practice.

Adult↗

PubMed2004

[Histological diagnosis after Pap smears detecting cancer or high-grade lesion of the cervix].

OBJECTIVE: The aim of the study is to analyze the histological-cytological correlations for Pap smears having detected cancer or high-grade squamous intra-epithelial lesion (HSIL) of the cervix. PATIENTS AND METHOD: The study about 311 women is retrospective. The average age is 36.4 years. Group 1 (histological diagnosis of high-grade or invasive lesion) includes 244 women (77.5%). Group 2 (histological diagnosis other than high-grade or invasive lesion) includes 37 women (11.9%) with a presumed diagnosis of HSIL. Group 3 (absence of histological follow-up) includes 30 women (9.6%) with a presumed diagnosis of HSIL. RESULTS: In group 1, the presumed cytological diagnosis is HSIL in 229 cases, squamous carcinoma in 11 cases and adenocarcinoma in two cases. In this group, the average delay between the Pap smear and the first histology is equal to two months. It is longer than 6 months in seven cases. The diagnosis of cancer or high-grade lesion is confirmed histologically on a first biopsy of the cervix in 196 cases, a second or a third biopsy in 10 cases, an endocervical curettage in six cases and a surgical specimen in 32 cases. In the group 2, the histological diagnosis is normal-benign in 14 cases (presumed cytological false positives) and condyloma-CIN 1 in 23 cases (presumed overevaluations). DISCUSSION AND CONCLUSION: Results highlight benefits of interactive exchanges between clinicians and pathologists, and the necessity of review of discordant cases by several pathologists in due time, with written comments and coding of the conclusions of the review. Histological follow-up is late or not done in some women.

Adolescent↗

PubMed2003

Double-blind crossover study with dolasetron mesilate, a 5-HT3 receptor antagonist in cerebellar syndrome secondary to multiple sclerosis.

Cerebellar syndrome is one of the most disabling developments in multiple sclerosis (MS). In neurodegenerative disorders, cerebellar syndrome is thought to be related to a neurochemical deficit of 5-hydroxytryptamine (5-HT). Previous studies found that a levorotatory form of 5-hydroxytryptophan, a 5-HT precursor, and ondansetron, a 5-HT(3) receptor antagonist, decreased cerebellar symptoms in Friedreich's ataxia and MS. We studied the effect of another 5-HT(3) receptor antagonist, dolasetron mesilate, on cerebellar syndrome in MS patients.Thirty-four MS patients were included in a placebo-controlled double-blind crossover study. They received a single dose of intravenous dolasetron mesilate or placebo. A quantitative evaluation of cerebellar syndrome using the nine-hole peg test and an ataxia score comprising static and kinetic parameters were performed before and after each treatment. No statistical difference was observed in the dolasetron mesilate group, compared with the placebo group. There was, however, inter-individual variability in the treatment response. This double-blind study on cerebellar syndrome in MS patients did not confirm the positive effect of dolasetron mesilate suggested by previous studies.

Adolescent↗

PubMed2003

A preprocessing method for improving data mining techniques. Application to a large medical diabetes database.

The Knowledge Discovery in Databases (KDD) methodology seems to be attractive on the analyze of large clinical databases. In the KDD process, the preprocessing step (data cleaning and handling of missing values) is paramount since it conditions the quality of the results obtained by data mining procedures and represents about 80% of the whole project time. The aims of the present study were to analyze this step and provide tools to handle inconsistent data and missing values. We have broken down the process into 3 main stages: data cleaning--explanatory study of missing values--choice of the procedure used for handling missing values. The data cleaning stage was based on a system of logical rules to correct mistakes and on cluster analysis to discard the poorly filled files. The missing-data mechanism was analyzed by means of multivariate statistical procedures. Two methods to deal with missing values were compared: imputation by the most common value (mode) and imputation using decision trees. This study was performed on a large medical diabetes database (23,601 patients) including numerous missing values. A system of logical rules allowed to correct mistakes on essential parameters (for example, the type of diabetes). Cluster analysis allowed to identify 10% of poorly filled files. After multivariate analysis, the missing-data mechanism could be considered as random. For variables with low number of missing values (< 10%) and categories (< 4), imputation using decision trees provided better results than imputation by mode.

Data Interpretation, Statistical↗

PubMed2001

Signal-averaged electrocardiography in children with anthracycline-induced cardiomyopathy.

The aim of the present study was to determine if signal-averaged ECG of patients with anthracycline-induced left ventricular dysfunction could differentiate between patients with anthracycline-induced cardiotoxicity and those without. Sixteen children with anthracycline-induced cardiomyopathy, aged 6.5 to 15.5 years (anthracycline dose = 198-737 mg/m2), and 31 patients aged 5.0 to 16.7 years, who received anthracyclines without evidence of left ventricular dysfunction (anthracycline dose = 120-517 mg/m2), were studied with signal averaged ECG. The two groups were comparable in age, body surface area, and time since completion of chemotherapy. Signal averaged ECG parameters of the patients were compared with data obtained from 530 healthy children. These parameters were converted to z-scores to account for growth-related changes in signal averaged ECG recordings. Z-scores for filtered QRS duration and low amplitude terminal signal < 40 microV were significantly lower (p = 0.002 and p = 0.015, respectively), and Z-score for root mean square voltage of the last -30 ms of filtered QRS tended to be higher (p = 0.06) in patients with left ventricular dysfunction. Filtered QRS duration lower than -1.5 SD was found in 4 of 16 patients with left ventricular dysfunction and in only 1 of 31 patients without (p < 0.05) yielding a sensitivity of 25% and a specificity of 97% to detect left ventricular dysfunction. Only 1 patient had late potentials; his left ventricular function was normal. Left ventricular mass index tended to be lower in patients with left ventricular dysfunction (p = 0.07), whereas left ventricular diastolic diameter was similar in the two groups. The mechanism that accounted for the difference in signal averaged-ECG between the two groups of patients could be linked with the decrease in left ventricular mass in patients with left ventricular dysfunction. In conclusion, children with left ventricular dysfunction following anthracycline therapy have a SA ECG different from those without left ventricular dysfunction, which is mainly characterized by a lower filtered QRS duration. A prospective study is needed in order to determine if this modification of SA ECG recordings precedes alteration of left ventricular function, and, therefore, if it could help in early detection of cardiac toxicity of anthracyclines.

Adolescent↗

PubMed2001

Chronic bilateral pallidal stimulation and levodopa do not improve gait in the same way in Parkinson's disease: a study using a video motion analysis system.

Chronic bilateral internal globus pallidus (GPi) stimulation allows control of levodopa induced dyskinesias (LID) and motor symptoms in severe Parkinson's disease (PD). The effect on gait has not been clearly established. Different results have been reported, mostly consisting of clinical data. The aim of this study was to evaluate, by means of a video motion analysis system (optoelectronic VICON system), the influence of bilateral GPi stimulation on gait in PD. Five patients underwent bilateral GPi stimulation. The preoperative and postoperative (3 months after surgery) clinical gait disturbances (items 29 and 30 of the motor UPDRS), as well as spatial and temporal gait measurements (namely cadence, velocity, stride and step times, single and double limb support times, stride and step lengths) were analysed in off condition (the patient had received no treatment for 12 hours or merely the lowest dose of levodopa allowing him to walk for the gait analysis) and in the on drug condition (after administration of 200 mg of levodopa). The gait analysis was performed with the VICON system. In off condition, there was a statistically significant improvement after surgery for UPDRS III and gait (clinically assessed). In on drug condition, there was a significant improvement for LID whereas UPDRS III and clinical assessment of gait were unchanged. The VICON system also showed that surgery improved gait especially in off condition, but also in on drug condition. Our method allowed exact quantification of the influence of surgery on gait characteristics. As compared with levodopa treatment, the effect of stimulation seems to be different. Indeed, the results suggest only limited effects of pallidal stimulation on the control of stride length and rather point to compensatory additional mechanisms.

Aged↗

PubMed2001

Practice-based buprenorphine maintenance treatment (BMT): how do French healthcare providers manage the opiate-addicted patients?

UNLABELLED: France was the first country to promote the extensive use of buprenorphine for the treatment of drug-addicted subjects through the primary care system. To assess both professional commitment and patients' characteristics, all the physicians and pharmacists of a French area having prescribed/dispensed buprenorphine from 2/12/96 (the official release date) to 1/31/98 were identified from data files of the Health Insurance and then interviewed. During the first 61 weeks of buprenorphine maintenance treatment (BMT), 27.5% of physicians and 51.2% of pharmacists of that area were involved; 142 patient records were documented. Features of the clinical routines spontaneously implemented for practice-based BMT were: a high level of on-site supervised dispensation by the pharmacist (71% at treatment induction and 23% thereafter); the absence of objective measurement of illicit drug use; and a low buprenorphine dosage. These features are consistent with the lack of physicians' experience and training, and also the relatively good status of the population treated (no HIV-positives, heroin use duration averaging 4.2 +/- 3.1 years, and 81.7% with stable accommodations). Despite liberal regulations guiding BMT, a negligible proportion of cases had a "nomadic" attitude (multiple buprenorphine prescribers/deliverers). The treatment outcomes (no deaths, three drug overdoses, improvement in occupational status) are encouraging. CONCLUSION: Practice-based BMT appears to be a safe and acceptable response to moderate heroin addiction, but further training of the professionals involved and longitudinal investigations of individual outcomes are needed.

Adult↗

PubMed2001

Assessing the Cox model assumption as a statistical tool for classifying lymphomas.

INTRODUCTION: The Cox model is widely used in medical research for comparing survival. Lymphomas might exhibit important differences in long-term cure rate despite a similar survival. METHODS: Using log-rank test, we compared event-free survival (EFS), and the survival of 64 patients with mantle cell lymphoma (MCL), 525 patients with follicular lymphoma, and 1136 patients with diffuse centroblastic lymphoma (CB). RESULTS: Although EFS and survival of MCL were significantly shorter than those of follicular lymphoma, checking the validity of the proportional hazards assumption shows that the distribution of rates of events and deaths over time did not differ in MCL and follicular lymphoma. In contrast, the ratios of hazards (events and deaths rates) did not remain constant over time in MCL and CB, because of a decrease in late events and deaths rates in the latter histological type. CONCLUSION: Checking the validity of the Cox model hypothesis might be a useful tool for assessing long-term cure rate in seldom lymphoma subtypes. Despite a short overall survival, MCL should not be considered to be an aggressive lymphoma, in which available chemotherapy may cure a subset of patients.

Adult↗

PubMed2001

Peripheral pulmonary arteries: how far in the lung does multi-detector row spiral CT allow analysis?

PURPOSE: To analyze the influence of multi-detector row spiral computed tomography (CT) on identification of peripheral pulmonary arteries. MATERIALS AND METHODS: Peripheral pulmonary arteries were analyzed on optimally opacified contrast material-enhanced spiral CT angiograms in 30 patients devoid of pleuroparenchymal disease who underwent scanning with multi-detector row CT (collimation, 4 x 1 mm; pitch, 1.7-2.0; scanning time, 0.5 second). Two series of scans were systematically generated from each data set, 1.25-mm-thick (group 1) and 3-mm-thick (group 2) sections, leading to the analysis of 600 segmental (20 arteries per patient), 1,200 subsegmental (40 arteries per patient), 2,400 fifth-order (80 arteries per patient), and 4,800 sixth-order (160 arteries per patient) pulmonary arteries in each group. RESULTS: Multi-detector row CT with reconstructed scans of 1.25-mm-thick sections (group 1) allowed (a) analysis of a significantly higher percentage of subsegmental arteries (94% in group 1 vs 82% in group 2; P <.001) and (b) a significantly higher percentage of fifth- and sixth-order arteries, respectively, identified in 74% and 35% of cases in group 1 and 47% and 16% in group 2 (P <.001). The causes for inadequate depiction of subsegmental branches in group 1 were partial volume effect (43%), anatomic variants (39%), and cardiac (17%) and respiratory (1%) motion artifacts. CONCLUSION: Multi-detector row CT with reconstructed scans of 1.25-mm-thick sections enables accurate analysis of peripheral pulmonary arteries down to the fifth order on spiral CT angiograms.

Angiography↗