The 2020 BMT CTN Myeloma Intergroup Workshop on Immune Profiling and Minimal Residual Disease Testing in Multiple Myeloma

The fifth annual Blood and Marrow Transplant Clinical Trials Network Myeloma Intergroup Workshop on Immune Profiling and Minimal Residual Disease Testing in Multiple Myeloma was conducted as one of the American Society of Hematology Annual Meeting Scientific Workshops on Thursday December 3, 2020. This workshop focused on four main topics: (1) integrating minimal residual disease into clinical trial design and practice; (2) the molecular and immunobiology of disease evolution and progression in myeloma; (3) adaptation of next-generation sequencing, next-generation flow cytometry, and cytometry by time of flight techniques; and (4) chimeric antigen receptor T-cell and other cellular therapies for myeloma. In this report, we provide a summary of the workshop presentations and discuss future directions in the field.

Can a Multistakeholder Prioritization Structure Support Regulatory Decision Making? A Review of Pediatric Oncology Strategy Forums Reflecting on Challenges and Opportunities of this Concept

Timely and successful drug development for rare cancer populations, such as pediatric oncology, requires consolidated efforts in the spirit of shared responsibility. In order to advance tailored development efforts, the concept of multistakeholder Strategy Forum involving industry, academia, patient organizations, and regulators has been developed. In this study, we review the first five pediatric oncology Strategy Forums co-organized by the European Medicines Agency between 2017 and 2020, reflecting on the outcomes and the evolution of the concept over time and providing an outline of how a "safe space" for multistakeholder engagement facilitated by regulators could be of potential value beyond pediatric oncology drug development.

ACCELERATE and European Medicines Agency Paediatric Strategy Forum for medicinal product development of checkpoint inhibitors for use in combination therapy in paediatric patients

The third multistakeholder Paediatric Strategy Forum organised by ACCELERATE and the European Medicines Agency focused on immune checkpoint inhibitors for use in combination therapy in children and adolescents. As immune checkpoint inhibitors, both as monotherapy and in combinations have shown impressive success in some adult malignancies and early phase trials in children of single agent checkpoint inhibitors have now been completed, it seemed an appropriate time to consider opportunities for paediatric studies of checkpoint inhibitors used in combination. Among paediatric patients, early clinical studies of checkpoint inhibitors used as monotherapy have demonstrated a high rate of activity, including complete responses, in Hodgkin lymphoma and hypermutant paediatric tumours. Activity has been very limited, however, in more common malignancies of childhood and adolescence. Furthermore, apart from tumour mutational burden, no other predictive biomarker for monotherapy activity in paediatric tumours has been identified. Based on these observations, there is collective agreement that there is no scientific rationale for children to be enrolled in new monotherapy trials of additional checkpoint inhibitors with the same mechanism of action of agents already studied (e.g. anti-PD1, anti-PDL1 anti-CTLA-4) unless additional scientific knowledge supporting a different approach becomes available. This shared perspective, based on scientific evidence and supported by paediatric oncology cooperative groups, should inform companies on whether a paediatric development plan is justified. This could then be proposed to regulators through the available regulatory tools. Generally, an academic-industry consensus on the scientific merits of a proposal before submission of a paediatric investigational plan would be of great benefit to determine which studies have the highest probability of generating new insights. There is already a rationale for the evaluation of combinations of checkpoint inhibitors with other agents in paediatric Hodgkin lymphoma and hypermutated tumours in view of the activity shown as single agents. In paediatric tumours where no single agent activity has been observed in multiple clinical trials of anti-PD1, anti-PDL1 and anti-CTLA-4 agents as monotherapy, combinations of checkpoint inhibitors with other treatment modalities should be explored when a scientific rationale indicates that they could be efficacious in paediatric cancers and not because these combinations are being evaluated in adults. Immunotherapy in the form of engineered proteins (e.g. monoclonal antibodies and T cell engaging agents) and cellular products (e.g. CAR T cells) has great therapeutic potential for benefit in paediatric cancer. The major challenge for developing checkpoint inhibitors for paediatric cancers is the lack of neoantigens (based on mutations) and corresponding antigen-specific T cells. Progress critically depends on understanding the immune macroenvironment and microenvironment and the ability of the adaptive immune system to recognise paediatric cancers in the absence of high neoantigen burden. Future clinical studies of checkpoint inhibitors in children need to build upon strong biological hypotheses that take into account the distinctive immunobiology of childhood cancers in comparison to that of checkpoint inhibitor responsive adult cancers.

ACCELERATE and European Medicine Agency Paediatric Strategy Forum for medicinal product development for mature B-cell malignancies in children

Paediatric Strategy Forums have been created by the multistakeholder organisation, ACCELERATE, and the European Medicines Agency to facilitate dialogue between all relevant stakeholders and suggest strategies in critical areas of paediatric oncology drug development. As there are many medicines being developed for B-cell malignancies in adults but comparatively few in children with these malignancies, a Paediatric Strategy Forum was held to discuss the best approach to develop these products for children. It was concluded that as current frontline therapy is highly successful, despite associated acute toxicity, de-escalation of this or substitution of presently used drugs with new medicines can only be undertaken when there is an effective salvage regimen, which is currently not available. Therefore priority should be given to developing treatment for patients with relapsed and refractory mature B-cell lymphomas. The consensus of the clinicians attending the meeting was that CAR T-cells, T-cell engagers and antibody drug conjugates (excluding those with a vinca alkaloid-like drug) presently have the greatest probability of providing benefit in relapse in view of their mechanism of action. However, as producing autologous CAR T-cells currently takes at least 4 weeks, they are not products which could be quickly employed initially at relapse in rapidly progressing mature B-cell malignancies but only for the consolidation phase of the treatment. Global, industry-supported, academic-sponsored studies testing compounds from different pharmaceutical companies simultaneously should be considered in rare populations, and it was proposed that an international working group be formed to develop an overarching clinical trials strategy for these disease groups. Future Forums are planned for other relevant paediatric oncologic diseases with a high unmet medical need and relevant molecular targets.

The European Medicines Agency Review of Carfilzomib for the Treatment of Adult Patients with Multiple Myeloma Who Have Received at Least One Prior Therapy

This article summarizes the scientific review of the application leading to regulatory approval of carfilzomib in combination with lenalidomide and dexamethasone in the European Union.

On November 19, 2015, a marketing authorization valid through the European Union was issued for carfilzomib in combination with lenalidomide and dexamethasone for the treatment of adult patients with multiple myeloma (MM) who have received at least one prior therapy.

In a phase III trial in patients with relapsed MM, median progression‐free survival (PFS) for patients treated with carfilzomib in combination with lenalidomide and dexamethasone (CRd) was 26.3 months versus 17.6 months for those receiving lenalidomide and dexamethasone alone (hazard ratio = 0.69; 95% confidence interval, 0.57–0.83; one‐sided log‐rank p value < .0001). The most frequently observed toxicity (grade ≥3, treatment arm vs. control arm) in the phase III trial included neutropenia (29.6% vs. 26.5%), anemia (17.9% vs. 17.7%), thrombocytopenia (16.8% vs. 12.3%), pneumonia (12.5% vs. 10.5%), fatigue (7.7% vs. 6.4%), hypertension (4.6% vs. 2.1%), diarrhea (3.8% vs. 4.1%), and respiratory tract infection (4.1% vs. 2.1%).

The objective of this article is to summarize the scientific review of the application leading to regulatory approval in the European Union. The scientific review concluded that the gain in PFS of 8.7 months observed with the combination of CRd was considered clinically meaningful and was supported by a clear trend in overall survival benefit, although the data were not mature. The delay in disease progression appeared superior to available alternatives in the setting of relapsed MM at the time of the marketing authorization of carfilzomib. Therefore, given the overall accepted safety profile, which was considered manageable in the current context, the benefit risk for CRd was considered positive.

Implications for Practice.

Carfilzomib (Kyprolis) was approved in the European Union in combination with lenalidomide and dexamethasone for the treatment of adult patients with multiple myeloma who have received at least one prior therapy. The addition of carfilzomib to lenalidomide and dexamethasone resulted in a clinically meaningful and statistically significant improvement of progression‐free survival compared with lenalidomide and dexamethasone, which was supported by a clear trend in overall survival benefit, although the data were not mature. At the time of the marketing authorization of carfilzomib, the delay in disease progression appeared superior to available alternatives in the setting of relapsed multiple myeloma. In terms of safety, the overall accepted safety profile was considered manageable.

The European Medicines Agency Review of Decitabine (Dacogen) for the Treatment of Adult Patients With Acute Myeloid Leukemia: Summary of the Scientific Assessment of the Committee for Medicinal Products for Human Use

: On September 20, 2012, a marketing authorization valid throughout the European Union (EU) was issued for decitabine for the treatment of adult patients aged 65 years and older with newly diagnosed de novo or secondary acute myeloid leukemia (AML) who are not candidates for standard induction chemotherapy. Decitabine is a pyrimidine analog incorporated into DNA, where it irreversibly inhibits DNA methyltransferases through covalent adduct formation with the enzyme. The use of decitabine was studied in an open-label, randomized, multicenter phase III study (DACO-016) in patients with newly diagnosed de novo or secondary AML. Decitabine (n = 242) was compared with patient's choice with physician's advice (n = 243) of low-dose cytarabine or supportive care alone. The primary endpoint of the study was overall survival. The median overall survival in the intent-to-treat (ITT) population was 7.7 months among patients treated with decitabine compared with 5.0 months for those in the control arm (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.69-1.04; p = .1079). Mature survival data after an additional year of follow-up were consistent with these results, with a median overall survival of 7.7 months in patients treated with decitabine and 5.0 months in the control arm (HR, 0.82; 95% CI, 0.68-0.99; p = .0373). Secondary endpoints, including response rates, progression-free survival, and event-free survival, were increased in favor of decitabine when compared with control treatment. The most common adverse drug reactions reported during treatment with decitabine are pyrexia, anemia, thrombocytopenia, febrile neutropenia, neutropenia, nausea, and diarrhea. This paper summarizes the scientific review of the application leading to approval of decitabine in the EU. The detailed scientific assessment report and product information (including the summary of product characteristics) for this product are available on the EMA website (http://www.ema.europa.eu).

IMPLICATIONS FOR PRACTICE

Acute myeloid leukemia (AML) remains an area of significant unmet need, especially in older patients. Older patients and those with comorbidities are often considered ineligible for standard induction therapy, and outcome for these patients is poor. Decitabine has favorable effects in terms of overall survival, which were considered clinically meaningful in the context of a manageable toxicity profile and after consideration of the lack of therapeutic alternatives for these patients. Decitabine is widely used in the treatment of AML in patients aged >60 years, as per current guidelines, including the European LeukemiaNet and the U.S. National Cancer Comprehensive Network.

The European Medicines Agency review of cabazitaxel (Jevtana®) for the treatment of hormone-refractory metastatic prostate cancer: summary of the scientific assessment of the committee for medicinal products for human use

On March 17, 2011 the European Commission issued a marketing authorization valid throughout the European Union for Jevtana® (Sanofi-Aventis, Paris, France) for the treatment of patients with hormone-refractory metastatic prostate cancer previously treated with a docetaxel-containing regimen. The active substance of Jevtana® is cabazitaxel acetone solvate, an antineoplastic agent that acts by disrupting the microtubular network in cells. The recommended dose of cabazitaxel is 25 mg/m2 administered as a 1-hour i.v. infusion every 3 weeks in combination with oral prednisone or prednisolone, 10 mg, administered daily throughout treatment. In the main study submitted for this application, a 2.4-month longer median overall survival time and a 30% lower risk for death were observed for cabazitaxel, compared with mitoxantrone. The most common side effects with cabazitaxel were anemia, leukopenia, neutropenia, thrombocytopenia, and diarrhea. This paper summarizes the scientific review of the application leading to approval in the European Union. The detailed scientific assessment report and product information, including the summary of product characteristics, are available on the European Medicines Agency Web site (http://www.ema.europa.eu).

Comparative validation of the growth hormone-releasing hormone and arginine test for the diagnosis of adult growth hormone deficiency using a growth hormone assay conforming to recent international recommendations

CONTEXT

The GHRH plus arginine (GHRH+Arg) test is a promising alternative to the insulin tolerance test (ITT) for diagnosis of adult GH deficiency (AGHD).

OBJECTIVES

The objectives of the study were to validate the GHRH+Arg test for diagnosis of AGHD, using the ITT as comparator and a GH assay calibrated according to recent international recommendations, and to study the repeatability and tolerance of both tests.

DESIGN

This was a multicenter, randomized, open-label, phase III study.

SETTING

The study was conducted at 10 French university hospitals.

SUBJECTS

Sixty-nine subjects (38 and 15 with high and low probability of GH deficiency, respectively, and 16 healthy controls) were randomized: 35 to the GHRH+Arg-GHRH+Arg-ITT test sequence and 34 to the ITT-ITT-GHRH+Arg test sequence.

INTERVENTIONS

Each subject underwent three tests of GH secretion separated by 24 h or more.

MAIN OUTCOME MEASURES

The primary variable used for response assessments was serum peak GH response. Test results were compared with the final AGHD diagnosis.

RESULTS

Peak GH responses in the two tests were strongly correlated. A cutoff value of 7.89 microg/liter for GHRH+Arg corresponding to 3 microg/liter for ITT was calculated. The cutoff value leading to 95% specificity with the GHRH+Arg test was measured at about 3.67 microg/liter (sensitivity 79.0%). Intermethod agreement and repeatability were high. Both tests were well tolerated. A preference for the GHRH+Arg test was expressed by 74% of subjects.

CONCLUSIONS

The GHRH+Arg test demonstrated good accuracy and repeatability, was at least as sensitive as the ITT, and was associated with better subject acceptability. The GHRH+Arg test represents a good alternative to the ITT for the diagnosis of AGHD.

Identifying and preventing adverse drug events in elderly hospitalised patients: a randomised trial of a program to reduce adverse drug effects

OBJECTIVES

Evaluate the impact of educational intervention in decreasing ADEs in elderly patients in a hospital setting.

DESIGN

Randomised prospective study.

SETTING

The study was performed in France in the Paris area, in 16 rehabilitation geriatric centres of APHP (Assistance Publique - Hôpitaux de Paris). Patient capacity per centre varied from 15 to 57 with a total of 526.

PARTICIPANTS

All the patients > or = 65 years hospitalized during the 4 week study period were included.

MEASUREMENTS

During a first 2 week phase without intervention ADE's were recorded in all centres. Then units were then randomised for an educational intervention or not. The educational phase lasted 1 week, without ADE tracking. Then, both types of units (I+ and I-) recorded ADEs for 2 weeks. Possible drug-related incidents were detected using a standardized check list (nurses) and a weekly review of all charts by investigators. Possible drug-related incidents were analysed by a group of reviewers selected from the authors to classify them as ADE or not.

RESULTS

576 patients (mean age: 83.6 +/- 7.9 years) were consecutively included. The mean number of drugs at inclusion was 9.4 +/- 4.24 drugs per patient. 223 out of 755 events were considered "probable" ADEs (29.5%). Among the 223 ADEs, 62 (28%) could have been prevented. The main outcome of this trial was the change in the proportion of ADEs in elderly patients in the intervention-units, compared to the control group. The main errors were: to high a dose (26%), double therapy (21%), under dose (13%), inappropriate drug (13%), drug-drug interaction (6%), previous same adverse drug reaction (3%) and miscellaneous (11.18%). After a specific educational intervention program, there were fewer ADEs in the intervention group (n = 38, 22%) than in the control group (n = 63, 36%; p = 0.004).

CONCLUSION

Educational programs could help reduce the prevalence of ADEs by 14% and encourage physicians to change outdated prescription habits.

Protocolisation, utilisation et développement des médicaments anticancéreux dans le cadre de la mise en place de la T2A

Drugs used in oncology represent more than half of the innovative and costly drugs which are not covered by a Group Homogène de Soins (DRG type classification) within the context of the case-mix based payment system (termed T2A). For these drugs, good practice reference guidelines have been drawn up by scientific societies and registration agencies. Recognised indications, relevant indications and situations where the treatment should not be prescribed are defined by the National Institute of Cancer. The reference guidelines should lead towards the good use of these drugs and allow the sick funds to control prescriptions. They should evolve with time, which means that bibliographic monitoring and independent expert opinion is necessary to update them as science provides new data. Manufacturers are involved in this process which in no case should undermine developmental efforts leading to registration. The objective of this protocolisation is to allow all patients early and legitimate access to drugs representing real therapeutic progress. These reference guidelines should be integrated into the life-cycle of a drug and should give rise to new developments allowing the good use of cancer products in situations which have been properly validated.

Evolution of the postoperative pericardial effusion after day 15: the problem of the late tamponade

STUDY OBJECTIVES

To evaluate, through clinical and transthoracic echocardiography (TTE) follow-up, the natural history of persistent pericardial effusion (PE) after postoperative day 15 in patients who were given and were not given anticoagulant therapy.

DESIGN AND PATIENTS

We retrospectively studied a cohort of 1,277 patients who were hospitalized between May 1997 and May 1999 in our center a mean (+/- SD) time period of 15 +/- 3 days after undergoing coronary artery bypass graft (CABG) surgery (856 patients) or valve replacement (VR) surgery (421 patients).

MEASUREMENTS

TTE was performed on mean (+/- SD) postoperative day 20 +/- 1 (TTE(1)) and postoperative day 30 +/- 2 (TTE(2)). PE severity was classified on a scale from grade 1 to grade 4.

RESULTS

On postoperative day 20 +/- 1, PE was present in 22% of the 1,277 patients and was more frequent after patients underwent CABG surgery than after undergoing VR surgery (25% vs 17%, respectively; p < 0.01). On postoperative day 30 +/- 2, the overall incidence of late tamponade in patients with PE was 4%. The incidence increased with the severity grade of PE at TTE(1) (p < 0.001). The negative predictive value of a severity grade < 2 at TTE(1) for late tamponade was 100%. Late tamponade incidence was higher after VR surgery than after CABG surgery (11% vs 2%, respectively; p < 0.01), and was higher in patients who had received anticoagulation therapy than in those who had not (8% vs 2%, respectively; p < 0.05).

CONCLUSION

Persisting PE is common after postoperative day 15 and is more frequent after undergoing CABG surgery than after undergoing VR surgery. The incidence of late tamponade is usually underestimated, and it increases with the presence of VR, anticoagulation therapy, and/or higher postoperative TTE severity grade. Our data suggest that only patients with a PE severity grade of >/= 2 (< 10% of patients) require TTE follow-up after postoperative day 20.

Sensitive determination of nefopam and its metabolite desmethyl-nefopam in human biological fluids by HPLC

Nefopam (NEF) and desmethyl-nefopam (DMN) were assayed simultaneously in plasma, globule and urine samples using imipramine as internal standard. A liquid-liquid extraction procedure was coupled with a reverse phase high-performance liquid chromatography system. This system requires a mobile phase containing buffer (15 mM KH(2)PO(4) with 5 mM octane sulfonic acid: pH 3.7) and acetonitrile (77:33, v/v) through (flow rate=1.5 ml/min) a C(18) Symmetry column (150x4.6 I.D., 5 micrometer particle size: Waters) and a UV detector set at 210 nm. Internal standard was added to 1 ml of plasma or globule sample or 0.5 ml of urine sample, prior to the extraction under alkaline ambiance with n-hexane. The limits of quantification were 1 and 2 ng/ml for both molecules in plasma and globule, respectively; 5 and 10 ng/ml for NEF and DMN in urine, respectively. The method proved to be accurate and precise: the relative error at three concentrations ranged from -13.0 to +12.3% of the nominal concentration for all molecule and biological fluid; the within-day and between-day precision (relative standard deviation %) ranged from 1.0 to 10.1% for all the molecules and biological fluids. The method was linear between 1 and 60 ng/ml for both molecules in the plasma; 2 and 25 ng/ml for both molecules in the globule; 25 and 250 ng/ml for NEF and 50 and 500 ng/ml for DMN in the urine: correlation coefficients of calibration curves (determined by least-squares regression) of each molecule were higher than 0.992 whatever the biological fluid and during the pre-study and in-study validations. This method was successfully applied to a bio-availability study of NEF in healthy subjects.

[Avoidable hospital drug prescription in the elderly. A review of the literature]

Elderly persons are particularly exposed to drug reactions, especially drug interactions subsequent to multiple prescriptions. It is also recognized that the drug risk is the leading hospital risk involving 1 to 10% of all hospitalized patients. An analysis of the avoidable nature of drug reactions leads to consideration of a sequence of 4 events leading to drug exposure: prescription, delivery, administration and compliance. Each event in this sequence corresponds to a distinct person: physician, pharmacist, nurse, patient. This suggests that the prevention of drug reactions in hospitalized elderly persons requires implementation of an "alert-causal attributability-avoidability-prevention" system by the healthcare teams where physicians, pharmacists, and nurses work in close coordination with the patient.

Repeatability of transcranial Doppler measurements of arterial blood flow velocities in healthy subjects

1. Transcranial Doppler measurements of the mean blood flow velocity and the resistance index in the middle cerebral artery are used to assess cerebral haemodynamics. The prerequisite for the use of these parameters in clinical pharmacology studies is an evaluation of their repeatability and spontaneous variation with time. 2. Repeatability of transcranial Doppler measurements of mean blood flow velocity and resistance index was investigated in healthy subjects by calculation of the repeatability coefficient as defined by the British Standards Institution. Intra-observer repeatability (comparison of two successive determinations by one observer, n = 30 subjects), between-observer repeatability (comparison of two successive measurements each performed by a different observer, n = 30) and long-term repeatability (comparison of two determinations performed at the same hour with a 1 week interval by one observer, n = 14) were assessed. In addition, the spontaneous evolution with time of mean blood flow velocity and resistance index was determined over an 8 h period (n = 14). 3. Repeatability coefficients for intra-observer repeatability, between-observer repeatability and long-term repeatability were 4.83, 4.59 and 3.32 cm/s for mean blood flow velocity (normal value = 61.2 +/- 10.2 cm/s) and 2.62, 3.12 and 3.49% for resistance index, respectively (normal value = 53.6 +/- 5.9%), indicating that transcranial Doppler measurements are repeatable enough to be used over periods of time of up to 1 week in clinical pharmacology studies. 4. Finally, a time effect was detected for mean blood flow velocity, indicating that this parameter undergoes diurnal variation.

Effects of an angiotensin converting enzyme inhibitor, ramipril, on intracranial circulation in healthy volunteers. off

1. The effects of a single oral dose (10 mg) of ramipril on (a) systemic haemodynamics (arterial pressure, cardiac output), (b) carotid artery haemodynamics (blood flow and diameter, pulsed Doppler technique), (c) intracranial haemodynamics (middle cerebral artery mean blood velocity, transcranial Doppler technique), and (d) renin-angiotensin system (plasma converting enzyme and renin activities) have been investigated and compared with those of a placebo during the 24 h period following administration in a randomized, double-blind and cross-over study performed in six healthy volunteers. 2. Ramipril induced a strong and sustained inhibition of plasma converting enzyme activity (-96% at 4 h, -63% at 24 h) and an increase in plasma renin activity (+993% at 8 h). 3. As compared with placebo, ramipril did not significantly affect arterial blood pressure, heart rate, cardiac output and total peripheral resistance. 4. Ramipril significantly increased carotid blood flow (by 27% at 8 h) without significantly changing carotid artery diameter, indicating, given the unchanged arterial pressure, an arteriolar vasodilation in the carotid territory. 5. The middle cerebral artery mean blood flow velocity underwent spontaneous modifications during the placebo period but these changes were not affected by ramipril. This lack of influence of ramipril on intracranial haemodynamics suggests that the drug-induced arteriolar vasodilation and increase in carotid blood flow only concern the extracranial, musculo-cutaneous part of the carotid territory.

[Validation of Oscillomat, a device for self-measurement of blood pressure. Comparison with mercury sphygmomanometers]

Self-measurement of arterial blood pressure (BP) is a valuable aid in the follow-up of hypertensive patients. Unfortunately, the devices utilized are not subject to certification and therefore must be validated. In this study, the accuracy and precision of BP measurement with the Oscillomat device were measured and simultaneously compared with those of a standard mercury sphygomomanometer in 60 subjects and with a random zero mercury sphygmomanometer in 44 subjects. The Oscillomat device correctly explored systolic and diastolic BP within a 55 to 210 mmHg range. Compared with the auscultatory method, it tended to underestimate systolic BP values by + 3 to -15 mmHg and diastolic B.P. values by + 1 to -15 mmHg.

[Non-invasive study of hemodynamics in peripheral arteries by pulsed Doppler associated with bidimensional echography. A preliminary study]

The purpose of this study is the validation of a 2D-echography and range-gated system to measure internal diameter, and instantaneous blood flow velocity, and to calculate the blood flow, in peripheral arteries (i.e. common carotid artery, femoral artery, and humeral artery). The artery is first visualized using the echographic array probe, its internal diameter (D) is determined and its cross sectional area (S) calculated; the array of the ultrasonic system and the doppler probe are attached and forme a fixed angle. The range-gated doppler system allows the measurement of instantaneous blood flow velocity, with a position of the sample volume covering the internal diameter. Instantaneous velocities are integrated on several cardiac cycles to calculate the mean velocity (Vm). (S. Vm) measures the blood flow. The echographic array probe allows a control of the doppler beam position. In vitro velocities have been measured (N = 20). The fixed angle is 38 degrees 30'; there is an obvious relationship between the calculated and the measured velocities (r = 0.982; p less than 0.0001). The intra-observer reproducibility of measures on common carotid arteries (CCA), femoral arteries (FA), and humeral arteries (HA). In 7 normal patients is, respectively: diameters: (4.9%, 4.12%, 10.2%); velocities: (8.9%, 10.6%, 10.2%). The inter-observers reproducibility is respectively: diameters: (5.6%, 5.4%, 11.4%); velocities: (6.5%, 5.7%, 6.3%). The comparison of 11 measures of diameters and velocities with 20 range-gated doppler gives an obvious relationship (respectively, r = 0.99 p less than 0.0001, r = 0.996, p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

[Cytoplasmic changes in retinal pigment epithelium (rpe) during cyclic lighting (author's transl)]

Cytochemical and stereological studies on frog (rana ridibunda) RPE during a 12 hrs dark/12 hrs light cycle. Rapid changes in surface density of endoplasmic reticulum and in volume density of myeloid bodies shortly after the onset of light. Numerical and volumetric density of microperoxisomes increased after the fourth hour of light, with a concomitant decrease in the volume of phagosomes.