Risk-based approach for the transfer of quantitative methods: bioanalytical applications.

The transfer of analytical methods from a sending laboratory to a receiving one requires to guarantee that this last laboratory will obtain accurate results. Undeniably method transfer is the ultimate step before routine implementation of the method at the receiving site. The conventional statistical approaches generally used in this domain which analyze separately the trueness and precision characteristics of the receiver do not achieve this. Therefore, this paper aims first at demonstrating the applicability of two recent statistical approaches using total error-based criterion and taking into account the uncertainty of the true value estimate of the sending laboratory, to the transfer of bioanalytical methods. To achieve this, they were successfully applied to the transfer of two fully automated liquid chromatographic method coupled on-line to solid-phase extraction. The first one was dedicated to the determination of three catecholamines in human urine using electrochemical detection, and the second one to the quantitation of N-methyl-laudanosine in plasma using fluorescence detection. Secondly, a risk-based evaluation is made in order to understand why classical statistical approaches are not sufficient to provide the guarantees that the analytical method will give most of the time accurate results during its routine use. Finally, some recommendations for the transfer studies are proposed.

Harmonization of strategies for the validation of quantitative analytical procedures: a SFSTP proposal part IV. Examples of application.

A harmonized approach for the validation of analytical methods based on accuracy profile was introduced by a SFSTP commission on the validation of analytical procedure. This fourth and last document aims at illustrating this methodology and the statistics used. Therefore the validation of real case methods are proposed such as methods for the quality control of drugs, for the quantitation of impurities in drug substances, for bioanalysis or for the determination of nutriments. Furthermore, different types of analytical methods are used in order to demonstrate the applicability of the proposed approach to a wide range of methods such as liquid chromatography (LC-UV, LC-MS), spectrophotometry or ELISA.

Harmonization of strategies for the validation of quantitative analytical procedures. A SFSTP proposal--part III.

In the first two documents [Ph. Hubert, J.J. Nguyen-Huu, B. Boulanger, E. Chapuzet, P. Chiap, N. Cohen, P.A. Compagnon, W. Dewé, M. Feinberg, M. Lallier, M. Laurentie, N. Mercier, G. Muzard, C. Nivet, L. Valat, J. Pharm. Biomed. Anal. 36 (2004) 579-586; Ph. Hubert, J.J. Nguyen-Huu, B. Boulanger, E. Chapuzet, P. Chiap, N. Cohen, P.A. Compagnon, W. Dewé, M. Feinberg, M. Lallier, M. Laurentie, N. Mercier, G. Muzard, C. Nivet, L. Valat, E. Rozet, J. Pharm. Biomed. Anal., in press], a recent SFSTP Commission on the validation of analytical procedure has introduced a harmonized approach for the validation of analytical procedures. In order to complete this guide, the statistical methodology allowing to correctly conclude about the validity of a procedure is proposed in this third part of the guide. Indeed all the steps to obtain the decision tool namely the accuracy profile are described and illustrated step by step by a numerical example. This tool, based on the concept of total error (bias+standard deviation) build with a beta-expectation tolerance interval, allows to easily take the right decision and simultaneously minimizing the risk of the future use of the analytical procedure.

Harmonization of strategies for the validation of quantitative analytical procedures. A SFSTP proposal--part II.

As reported in a previous paper, the main objective of the new commission of the Société Française des Sciences et Techniques Pharmaceutiques (SFSTP) was the harmonisation of approaches for the validation of quantitative analytical procedures. In a series of meetings, members of this Commission have first tried to review the objectives of analytical methods and the objectives of validation methods and to recommend the use of two-sided beta-expectation tolerance intervals for total error of validation samples (accuracy profile) in the acceptance/rejection of analytical method in validation phase. In the context of the harmonization, the other objectives were: (i) to propose a consensus on the norms usually recognized, while widely incorporating the ISO terminology; (ii) to recommend to validate the analytical procedure accordingly to the way it will be used in routine; (iii) to elaborate a rational, practical and statistically reliable strategy to assure the quality of the analytical results generated. This strategy has been formalised in a guide and the three latter objectives made by the Commission are summarised in the present paper which is the second part of summary report of the SFSTP commission. The SFSTP guide has been produced to help analysts to validate their analytical methods. It is the result of a consensus between professionals having expertise in analytical and/or statistical fields. The suggestions presented in this paper should therefore help the analyst to design and perform the minimum number validation experiments needed to obtain all the required information to establish and demonstrate the reliability of its analytical procedure.

Comparison of two methods (left carotid artery and abdominal aorta) for surgical implantation of radiotelemetry devices in CD-1 mice.

The goal of this study was to compare two surgical methods, the left carotid (LC) and the abdominal aorta (AA), for mouse instrumentation with telemetry devices, to determine the best method for measuring cardiovascular (CV) parameters by radiotelemetry in freely moving mice. Surgery success rate, postsurgical recovery rate, clinical parameters, CV data (baseline and response to nicotine) and circadian rhythm measurements were compared between these techniques. Brains of LC-implanted mice were evaluated for potential ischaemia by direct observation of the Circle of Willis anatomy and histopathology. For this purpose, a total of 31 CD-1 male mice were instrumented with PA C20 devices (10 with LC and 21 with AA). Mortality, morbidity, physical examination, body weight (BW), water and food consumption (W/FC), mean blood pressure (MBP) and heart rate (HR) were monitored daily during the recovery period (10 days). CV baseline data were recorded continuously during two periods of four days, and finally, both LC- and AA-implanted mice received an acute subcutaneous administration of 1 mg/kg nicotine; BP and HR were recorded during 5 h after nicotine administration. Results showed that, in LC-implanted mice, 80% survived surgery and recovered well. In contrast, only 57% of mice implanted with the AA technique survived surgery and some presented lethal complications. Both techniques had similar recovery times for BW and W/FC, comparable return to normal circadian rhythm (day 6 post-surgery) and similar CV baseline values. No significant differences were observed in CV response to nicotine between both groups of implanted CD-1 mice. No histopathological changes suggestive of ischaemia were noted in the brain of mice implanted in the LC. Six out of the eight LC-implanted mice remained in good health and had good pressure signal for at least 100 days post-surgery, while most of the AA-implanted mice lost the signal pressure within 14-49 days post-surgery. In conclusion, we believe that LC implantation in mice is superior to the AA technique and is more appropriate for long-term telemetry studies, especially for smaller (transgenic) animals.

Comparison of FT-NIR transmission and UV-vis spectrophotometry to follow the mixing kinetics and to assay low-dose tablets containing riboflavin.

For several years, near-infrared spectroscopy (NIRS) has become an analytical technique of great interest for the pharmaceutical industry, particularly for the non-destructive analysis of dosage forms. The goal of this study is to show the capacity of this new technique to assay the active ingredient in low-dosage tablets. NIR spectroscopy is a rapid, non-destructive technique and does not need any sample preparation. As an example, a binary mixture of microcrystalline cellulose and riboflavin was used to prepare tablets of different weights by direct compression. A prediction model was built by using a partial least square regression fit method. The NIR assay was performed by transmission. The results obtained by NIR spectroscopy were compared with a conventional UV-vis spectrophotometry method. The study showed that tablets can be individually analysed by NIR with high accuracy. It was shown that the variability of this new technique is less important than that of the conventional method which is the UV-vis spectrophotometry.

A new validation approach applied to the GC determination of impurities in organic solvents.

Organic solvents such as methanol, acetone, dichloromethane or toluene are frequently used in the pharmaceutical industry. The manufacturing of new active pharmaceutical ingredients (APIs) under GMP conditions commands to control adequately the quality of the different ingredients happening in the synthesis. Organic solvents have therefore to be controlled and their purity has to be determined before any GMP synthesis. A selective gas chromatography (GC) method has been developed to determine the purity of acetone, dichloromethane, methanol and toluene. Using this method, the main contaminants of each organic solvent can be quantified. Moreover, the developed method allows the simultaneous determination of ethanol, isopropanol, chloroform, benzene, acetone, dichloromethane, methanol and toluene. Propionitrile was used as the internal standard. The separation was obtained on a CP-SIL 8-CB low bleed/MS column (60 m x 0.32 mm i.d.x1.0 microm coating thickness). The GC method was fully validated using a new approach based on the accuracy profile as a decision tool. The determination of beta-expectation tolerance intervals for the estimation of total error - including both bias and precision - is used to better reflect the actual performances of the method, which is definitively the objective of the validation. The different validation criteria such as selectivity, response function, trueness, precision, accuracy, linearity or limits of detection and quantification were considered. The method was found to be able to quantitate with a good accuracy impurities around the 0.1% (v/v) concentration level for the different solvents.

The transfer of a LC-UV method for the determination of fenofibrate and fenofibric acid in Lidoses: use of total error as decision criterion.

Two new statistical approaches to assess the validity of the transfer of a LC-UV method for the determination of fenofibrate and fenofibric acid were investigated and compared to the conventional approaches generally used in this domain. These new approaches, namely the Tolerance Interval and the Risk approaches, are based on the simultaneous evaluation of the systematic (or trueness) and random (or precision) errors of the transfer into a single criterion called total error (or accuracy). The results of the transfer showed that only the total error based approaches fulfilled the objective of an analytical method transfer, i.e. to give guarantees that each future measurement made by the receiving laboratory will be close enough to the true value of the analyte in the sample. Furthermore the Risk approach was the most powerful one and allowed the estimation of the risk to have future measurements out of specification in the receiving laboratory, therefore being a risk management tool.

Prognostic value of bone sialoprotein expression in clinically localized human prostate cancer.

BACKGROUND: Bone sialoprotein (BSP), a bone matrix protein, was recently found to be expressed ectopically in breast cancer and to have a statistically significant association with poor prognosis and the development of bone metastases in that disease. These data prompted us to investigate whether BSP might also be expressed in human prostate cancer, which often metastasizes to bone, and be predictive for progression risk. METHODS: Tissue sections from 180 patients who had undergone a radical prostatectomy for localized prostate cancer were analyzed immunohistochemically for BSP expression. Biochemical progression was defined as an increasing serum prostate-specific antigen level of 0.5 ng/mL or more. Statistical analysis was used to assess associations between pathologic findings and level of BSP expression, and a Cox proportional hazards model was used to determine which clinical and histologic parameters, including stage, Gleason score, and BSP expression (immunostaining intensity and extent), were independently associated with biochemical progression. All P values were two-sided. RESULTS: Most of the prostate cancer lesions examined (78.9%) expressed detectable levels of BSP, compared with no or low expression in the adjacent normal glandular tissue. A statistically significant association was found between BSP expression and biochemical progression in both univariate and multivariate analyses. After a follow-up interval of 3 years, the biochemical relapse rate was 36.7% (95% confidence interval [CI] = 23.4%-47.7%) in patients whose tumors expressed high levels of BSP compared with 12.1% (95% CI = 2.3%-20.8%) in patients whose tumors expressed no or a low detectable level of the protein (logrank test, P = .0014). BSP expression status could identify those patients at higher risk of biochemical progression (logrank test, P<.05) among patients with moderately differentiated tumors or with pathologically confined tumors. CONCLUSIONS: To our knowledge, this study is the first to demonstrate BSP expression in human prostate cancer and to highlight the protein's statistically significant prognostic value in patients with clinically confined prostate adenocarcinomas.

Low-level exercise echocardiography detects contractile reserve and predicts reversible dysfunction after acute myocardial infarction: comparison with low-dose dobutamine echocardiography.

OBJECTIVES: The aim of this study was to evaluate low-level exercise echocardiography (LLEE) in detecting contractile reserve and predicting functional improvement of akinetic myocardium early after acute myocardial infarction (AMI). BACKGROUND: Experimental and clinical studies have shown that low-dose dobutamine enhances contractile function of dyssynergic but viable myocardium in patients with recent AMI. We hypothesized that endogenous catecholamines produced during a LLEE test could serve as a myocardial stressor to elicit contractile reserve. METHODS: Fifty-two consecutive patients with first AMI and > or =2 akinetic segments in the infarct-related territory underwent 5 +/- 2 days after AMI low-dose dobutamine echocardiography (LDDE) (5, 10 and 15 microg/kg/min) and LLEE (25 W during 3 min on a supine bicycle, with continuous echocardiographic recording). Both tests were performed on the same day, in random order. Follow-up echocardiography was obtained one month later. Regional wall thickening was semi-quantitatively assessed using a 16-segment, 5-grade scale model. Contractile reserve was defined as improvement in wall thickening of > or =1 grade. RESULTS: Mean increase in heart rate during stress tests was 15 +/- 7 beats/min with LLEE and 13 +/- 6 beats/min with LDDE (p = NS). Contractile reserve was detected in 119 (55%) of 217 akinetic segments at LLEE and in 137 (63%) segments at LDDE. At follow-up study, functional improvement was identified in 139 (64%) segments. Sensitivity, specificity and positive and negative predictive values for predicting functional recovery were 81%, 92%, 95% and 73%, respectively, for LLEE, and 91%, 86%, 92% and 84%, respectively, for LDDE. Moreover, there was a good correlation between systolic wall thickening measured in the center of the dyssynergic area during stress tests and at follow-up study: r = 0.77, p < 0.001 with exercise testing and r = 0.73, p < 0.001 with dobutamine testing. CONCLUSIONS: Low-level exercise echocardiography provides a promising alternative to LDDE for identifying myocardial viability and predicting reversible dysfunction early after AMI.

Tumor necrosis factor alpha decreases, and interleukin-10 increases, the sensitivity of human monocytes to dexamethasone: potential regulation of the glucocorticoid receptor.

Resistance to glucocorticoid therapy has been observed in patients with autoimmune/inflammatory diseases and may be related to the inflammatory process itself. The aim of this study was to examine the ability of tumor necrosis factor alpha (TNFalpha, a proinflammatory cytokine) and interleukin (IL)-10 (an anti-inflammatory cytokine) to differentially regulate the sensitivity of human monocytes/macrophages to glucocorticoids. To accomplish this, we first analyzed the pattern of TNFalpha and IL-10 inhibition by dexamethasone in LPS-stimulated whole-blood cell cultures. Second, we studied the modulation of the sensitivity of these cells to dexamethasone by preincubation with TNFalpha or IL-10 and measurement of LPS-stimulated IL-6 secretion. In addition, we evaluated the effect of dexamethasone on phorbolmyristate-acetate-stimulated IL-1 receptor antagonist secretion by the human monocytic cell line U937. Finally, we investigated whether the modulation of corticosensitivity in TNFalpha- and IL-10-pretreated U937 cells was related to a change of the glucocorticoid receptor concentration and affinity. Dexamethasone had different effects on LPS-induced TNFalpha and IL-10 secretion; whereas it suppressed TNFalpha in a dose-dependent fashion, its effect on IL-10 secretion was biphasic, producing stimulation at lower, and inhibition at higher doses. The concentration of LPS employed influenced the effect of dexamethasone on IL-10 secretion (P < 0.001). Pretreatment with TNFalpha diminished, and with IL-10 improved, the ability of dexamethasone to suppress IL-6 secretion in whole-blood cell cultures (P < 0.01 for both) and to enhance IL-1 receptor antagonist secretion by U937 cells (P < 0.05 for both). TNFalpha decreased (P < 0.001), while IL-10 increased (P < 0.001), the concentration of dexamethasone binding sites in these cells, with no discernible effect on their binding affinity. We conclude that glucocorticoids differentially modulate TNFalpha and IL-10 secretion by human monocytes in a LPS dose-dependent fashion and that the sensitivity of these cells to glucocorticoids is altered by TNFalpha or IL-10 pretreatment; TNFalpha blocks their effects, whereas IL-10 acts synergistically with glucocorticoids. This is accompanied by opposite glucocorticoid receptor changes, respectively opposing and favoring glucocorticoid actions. This study suggests that the pattern of pro-/antiinflammatory cytokine secretion may alter the response of patients to glucocorticoid therapy.

Evaluation of frequency and type of errors detected by a computerized record and verify system during radiation treatment.

BACKGROUND: Computerized record and verify systems (RVS) have been introduced to improve the precision of radiation treatment delivery. These systems prevent the delivery of ionizing radiations when the settings of the treatment machine do not match the intended parameters within some maximal authorized deviation. PURPOSE: To assess the potential alteration of the frequency of errors associated with the use of RVS during radiation treatment delivery. MATERIALS AND METHODS: The software of the RVS was altered in order to record the settings actually used for radiation treatment delivery whereas the verification function was suppressed. At the end of the study period, the settings used during daily administration of radiation treatment were compared to the parameters recorded in the RVS using the computer. They were also compared with the planned ones written in the patient treatment chart. RESULTS: Out of the 147,476 parameters examined during the study period, 678 (0.46%) were set erroneously. At least one error occurred in 628 (3.22%) of the 19,512 treated fields. An erroneous parameter was introduced in the RVS memory in 22 (1.17%) of the 1885 fields. CONCLUSIONS: RVS has the potential to improve precision of radiation treatment delivery by detecting a significant number of setting errors. However, excessive confidence in RVS could lead to repeated errors as there is a potential for the entry of erroneous parameters into the RVS memory.

Compliance with antidepressants in a primary care setting, 1: Beyond lack of efficacy and adverse events.

BACKGROUND: Treatment guidelines recommend antidepressant treatment be continued for at least 6 months to ensure maximal improvement and to prevent relapse. Naturalistic studies show that the average length of treatment is shorter than 6 months and that dropout rates are high. Factors leading patients to discontinuation of therapy are not well understood. This study investigates when and why patients stop treatment and whether they inform their doctors. METHOD: Patients (N = 272) receiving antidepressant therapy due to an episode of major depressive disorder (DSM-IV) were asked to complete an antidepressant compliance questionnaire. Patients were then telephoned monthly while they continued on antidepressant therapy, up to 6 months. During each call, patients were asked standard questions. RESULTS: By endpoint, 53% of patients had discontinued antidepressant treatment. The most common reason given was "feeling better." However, different dropout reasons were prevalent at different times after initiation of therapy. Overall, 24% of the patients did not inform their physician about stopping the antidepressant medication. The likelihood of patients' informing their physicians differed according to the patients' reasons for discontinuation and according to the patients' perceptions of their relationship with their physicians. CONCLUSION: These results provide new guidelines for improving compliance. Strategy should be adapted to the stage of treatment, as patients' reasons for discontinuation vary as treatment progresses. The attitude of the physician and the information provided by the physician significantly influence whether patients inform the physician when they discontinue antidepressant therapy.

Compliance with antidepressants in a primary care setting, 2: the influence of gender and type of impairment.

BACKGROUND: DSM-IV diagnosis of major depressive disorder includes a requirement that symptoms result in significant clinical distress or impairment. This criterion is difficult to assess and is often overlooked. This study examines the use of the Sheehan Disability Scale as a possible method of assessing impairment, as well as the relationship between functioning and discontinuation of antidepressant medication. METHOD: Patients (N = 272) receiving antidepressant therapy due to an episode of major depressive disorder were asked to complete an antidepressant compliance questionnaire. Patients were telephoned monthly while they continued on antidepressant therapy, up to 6 months. During each call, the Sheehan Disability Scale was administered. RESULTS: Of patients referred to this study, 94.8% met DSM-IV criteria of at least 5 symptoms of major depressive disorder. Most patients had initial scores ranging from 5 to 8 on all 3 Sheehan disability subscales (occupational, social, and family functioning); 72% of patients had at least moderate impairment (scores > or = 4) on all 3 subscales. After 8 weeks of treatment, 42% of patients had scores < 4 on all 3 subscales (recovery); after 24 weeks, 64% of patients had scores < 4 on all 3 subscales. Dropout risk in men was related to improvement in occupational, social, and family functioning, whereas dropout risk in women was related only to improvement in family functioning. CONCLUSION: The Sheehan Disability Scale can be valuable in assessing impairment and thus in correctly diagnosing major depressive disorder. We suggest that scores of 4 or more (moderate impairment) on all 3 subscales indicate sufficient impairment for a strict diagnosis of major depressive disorder. Functional symptoms continued to improve for up to 24 weeks on antidepressant therapy, suggesting 6 months or more of therapy is necessary for maximum functional improvement. Premature discontinuation of antidepressant therapy is more likely to occur in women who experience significant improvement in family functioning or men who experience significant improvement in any functional area.

Comparison of rectal and infrared ear temperatures in older hospital inpatients.

OBJECTIVES: To assess the agreement between infrared emission detection (IRED) ear and rectal temperatures and to determine the validity of IRED ear thermometry in detecting rectal fever. DESIGN: Prospective, convenience sample, unblinded study. SETTING: An acute geriatric unit (teaching hospital) and a multidisciplinary intensive care unit. PARTICIPANTS: The study included 45 inpatients (26 women and 19 men), aged 78.3+/-6.9 years, admitted over a 4-month period. Twelve of the patients were definitely infected. MEASUREMENTS: Sequential rectal (RT) and ear temperature (ET) measurements were performed using mercury-in-glass and IRED ear thermometers, respectively. IRED ear temperatures were measured at both ears (unadjusted mode), with the highest of six ear temperatures considered the true value. RESULTS: Mean RT (37.39 degrees C +/- 0.52 degrees C) was significantly (P<.001) higher than mean ET (36.89 degrees C +/-0.59 degrees C). A highly significant positive correlation was found between RT and ET (slope = 0.69; 95% CI, 0.52-0.86; P<.001; r = 0.78). The mean bias (mean of the differences) between RT and ET was 0.50 degrees C +/-0.37 degrees C (95% CI, 0.41 degrees C-0.59 degrees C), and the 95% limits of agreement -0.22 degrees C and 1.23 degrees C (95% CI, -0.38 degrees C to 1.39 degrees C). According to the standard criterion (RT > or =37.6 degrees C), 14 patients were febrile. Using an optimum IRED ear fever threshold (37.2 degrees C), the sensitivity and specificity of IRED ear thermometry for predicting rectal fever were 86% and 89%, respectively (positive predictive value, 80%; negative predictive value, 93%). CONCLUSIONS: The degree of agreement between rectal temperature and the highest of six IRED ear temperatures was acceptable. Using an optimal IRED ear fever threshold of 37.2 degrees C (99 degrees F), IRED ear thermometry had acceptable sensitivity and specificity for predicting rectal fever.

Effects of dexamethasone on the profile of cytokine secretion in human whole blood cell cultures.

EXPERIMENTAL OBJECTIVES: The interaction between the endocrine and immune systems is a very intriguing area. Endogenous glucocorticoids, as end-effectors of the hypothalamo-pituitary-adrenal axis, inhibit the immune and inflammatory responses and are used as immunosuppressive drugs in many inflammatory, autoimmune and allergic diseases. The aims of this study were to investigate the effects of dexamethasone on the profile of cytokine secretion in whole blood cell cultures from healthy subjects and to analyse the gender-related sensitivity to dexamethasone on each cytokine secretion. RESULTS: There was a significant inhibition by dexamethasone (from 1 to 100 nM) on the secretion of monokines (IL-1beta, IL-6, IL-8 and TNF alpha) and lymphokines (IL-2, IL-4, IL-10 and IFN gamma), either after LPS or PHA stimulation (P < 0.01). Interleukin 4 and IL-10 were less inhibited than IFN gamma (P < 0.05 at 1 nM, P < 0.01 at 10 nM and P < 0.001 from 100 nM to 10 microM). No gender difference was observed in the rate of inhibition of the secretion of each cytokine. CONCLUSION: This study shows that the inhibition of cytokine secretion by dexamethasone is more marked on Th1-type cytokines than on Th2-type cytokines. These data support the idea that glucocorticoids may induce a shift from the Th1 to Th2 profile of cytokine secretion.

A four-parameter index of marrow dysplasia has predictive value for survival in myelodysplastic syndromes.

Marrow dysplasia is a major characteristic of patients with myelodysplastic syndrome (MDS), along with marrow blastosis, cytopenia and cytogenetic anomalies. However, the impact of the degree of marrow dysplasia on survival has not been fully assessed. In this retrospective analysis of 111 patients selected according to the IPSS criteria of MDS diagnosis, the presence or absence of 21 dysplasia characteristics recognizable in bone marrow smears stained by the May-Grünwald-Giemsa method was correlated with patient survival. Using Cox proportional hazards regression analysis, megaloblastosis (MEGALO), neutrophil agranularity (AGRAN) and hypogranularity (HYPOGRAN) were highly significant predictors (p < 0.005), and Pelger-Huët anomaly (PELGHUET) a significant predictor (p = 0.05), of patient survival. The regression analysis yielded a dysplasia-based risk index (DI) where DI = 1.26 MEGALO + 0.82 AGRAN - 1.08 HYPOGRAN + 0.45 PELGHUET. The two subgroups of 60 and 47 patients with DI < or = 0 and > 0 showed highly significant differences in median survivals (2.6 vs 1.1 yrs; p <0.0001). Multivariate analysis further showed that DI offered additional predictive power that was independent of that provided by the IPSS (p=0.002 and 0.001 respectively). Analysis of survival curves stratified for IPSS and DI showed that the additional predictive power offered by inclusion of the DI essentially concerned the IPSS low/INT-1 risk categories. Further stratification for age did not improve survival prediction. The data indicate that a set of 4 dysplasia parameters can offer some prediction for survival of MDS patients in addition to that provided by the IPSS. Further multicenter studies should aim at including some form of evaluation of the degree of dysplasia in prognostic systems.

Effects of gastroplasty on body weight and related biological abnormalities in morbid obesity.

Obesity is a prevalent metabolic disorder associated with high morbidity and mortality rates. Medical treatment rarely succeeds, and bariatric surgery has been proposed as an alternative therapy. The purpose of this non-controlled retrospective study was to evaluate time-course changes in body weight in severely obese patients who underwent vertical ring gastroplasty or adjustable silicone gastric banding, and to assess the prevalence and potential reversibility of several of the biological abnormalities associated with morbid obesity. From an initial cohort comprising 658 patients, regular body weight measurements and biological data were obtained in 505 patients [419 females, 86 males; age 36 +/- 11 years; body mass index 42.7 +/- 6.9 kg/m2; (mean +/- SD)] with a mean follow-up of 26 +/- 14 months. Mean weight loss was 32 +/- 16 kg. Most weight reduction occurred within the first 6 months, followed by near-stabilisation or even slight weight regain. Most biological parameters were obtained before surgery and after at least 6 months of follow-up. The high prevalence and severity of metabolic disturbances associated with the insulin resistance syndrome (hyperglycaemia, hyperinsulinaemia, decreased HDL cholesterol, hypertriglyceridaemia, elevated fibrinogen levels and hyperuricaemia) before gastroplasty were significantly decreased after weight loss. No major biological deficiencies were observed following gastroplasty, except low iron serum levels. It is concluded that marked weight loss associated with gastroplasty involved a remarkable reduction in the prevalence and severity of several biological abnormalities classically considered as cardiovascular risk factors.

Adherence to treatment regimen in depressed patients treated with amitriptyline or fluoxetine.

OBJECTIVE: Non-compliance presents a constant challenge to effective therapy. Many studies only investigate early treatment discontinuation and not other measures like adherence to treatment regimen. We compared adherence in depressed patients using either a selective serotonin reuptake inhibitor (fluoxetine) or a tricyclic antidepressant (amitriptyline), and examined its clinical relevance through adverse events, drop-out rates, and outcome. Adherence was measured electronically with the MEMS (Medication Event Monitoring System). DESIGN: Nine-week double blind, randomized controlled trial. SETTING: Ambulatory psychiatric care. PATIENTS: Random sample of 66 depressed (DSM-III-R criteria) patients. INTERVENTION: Fluoxetine 20 mg or amitriptyline 150 mg. MAIN OUTCOME MEASURES: Time course of adherence and its relation to severe adverse events, drop-outs and outcome. RESULTS: Non-adherence to the treatment regimen occurred frequently in both treatment groups: 31% of patients had at least one 3-day drug holiday, and 34% of patients had at least one episode of three pills in a 24-h period. Over-consumption occurred more frequently during the early phases of treatment while under-consumption occurred more frequently during the later phases. Patients on amitriptyline (P=0.03) and patients with a higher pill intake (P=0.01) experienced more severe adverse events. Patients on amitriptyline (P=0.009) and patients with a lower adherence to the treatment regimen (P=0.004) discontinued from treatment more frequently. The final Hamilton score was significantly predicted by a longer duration of treatment and by a better adherence, but only in amitriptyline users. CONCLUSIONS: Non-adherence to the treatment regimen has important clinical consequences. Pharmacodynamics and human behavior predict risk for severe adverse events and drop-outs. Moreover, in amitriptyline users but not in fluoxetine users, better adherence predicts a better outcome.

Evaluation of a diphenylphosphorylazide-crosslinked collagen membrane for guided bone regeneration in mandibular defects in rats.

In the present study, the potential of a diphenylphosphorylazide-crosslinked type I bovine collagen membrane was evaluated in the healing of mandibular bone defects applying the biological concept of guided bone regeneration. The experiment was carried out on 25 Wistar rats. After exposing the mandibular ramus bilaterally, 5 mm diameter full-thickness circular bone defects were surgically created. While the defect on one side was covered by the membrane (experimental), the defect on the other side was left uncovered (control) before closure of the overlying soft tissues. The rats were sacrificed in groups of 5 after 7, 15, 30, 90, and 180 days of healing. Although at early stages of healing similar amounts of bone formation were observed in the experimental and control defects, after 1 month of healing, most of the experimental defects were completely closed with new bone, while in the control defects, only limited amounts of new bone were observed at the rims and in the lingual aspect of the lesions. In the 90- and 180-day animals, all experimental defects were completely closed, while in the control defects, no statistically significant increase in bone regeneration was observed. The increase in percentage of bone regeneration in the experimental defects was statistically significant between the 15-day specimens as compared with the 7-day specimens (P < 0.01) and likewise between 30-day and 15-day specimens (P < 0.001). It can be concluded that a DPPA-crosslinked collagen membrane yields biocompatibility, ad hoc mechanical hindrance, and handling characteristics suitable for guided bone regeneration applications in this experimental model.