Evaluation of S201086/GLPG1972, an ADAMTS-5 inhibitor, for the treatment of knee osteoarthritis in ROCCELLA: a phase 2 randomized clinical trial

OBJECTIVE

To evaluate the efficacy and safety of the anti-catabolic ADAMTS-5 inhibitor S201086/GLPG1972 for the treatment of symptomatic knee osteoarthritis.

DESIGN

ROCCELLA (NCT03595618) was a randomized, double-blind, placebo-controlled, dose-ranging, phase 2 trial in adults (aged 40-75 years) with knee osteoarthritis. Participants had moderate-to-severe pain in the target knee, Kellgren-Lawrence grade 2 or 3 and Osteoarthritis Research Society International joint space narrowing (grade 1 or 2). Participants were randomized 1:1:1:1 to once-daily oral S201086/GLPG1972 75, 150 or 300 mg, or placebo for 52 weeks. The primary endpoint was change from baseline to week 52 in central medial femorotibial compartment cartilage thickness (cMFTC) assessed quantitatively by magnetic resonance imaging. Secondary endpoints included change from baseline to week 52 in radiographic joint space width, Western Ontario and McMaster Universities Osteoarthritis Index total and subscores, and pain (visual analogue scale). Treatment-emergent adverse events (TEAEs) were also recorded.

RESULTS

Overall, 932 participants were enrolled. No significant differences in cMFTC cartilage loss were observed between placebo and S201086/GLPG1972 therapeutic groups: placebo vs 75 mg, P = 0.165; vs 150 mg, P = 0.939; vs 300 mg, P = 0.682. No significant differences in any of the secondary endpoints were observed between placebo and treatment groups. Similar proportions of participants across treatment groups experienced TEAEs.

CONCLUSIONS

Despite enrolment of participants who experienced substantial cartilage loss over 52 weeks, during the same time period, S201086/GLPG1972 did not significantly reduce rates of cartilage loss or modify symptoms in adults with symptomatic knee osteoarthritis.

AB0860 STUDY DESIGN OF ROCCELLA: A PHASE 2 CLINICAL TRIAL WITH A DISEASE-MODIFYING OSTEOARTHRITIS DRUG CANDIDATE GLPG1972/S201086

Background:

Loss of articular cartilage is one of the major signs of osteoarthritis (OA). Aggrecan, the main proteoglycan component of the extracellular matrix of articular cartilage is cleaved by ADAMTS-5 (A Disintegrin And Metalloproteinase with ThromboSpondin-motif-5).1GLPG1972/S201086, a potent and highly selective inhibitor of ADAMTS-5, is an oral Disease-Modifying OsteoArthritis Drug (DMOAD) candidate. In a pooled Phase 1 safety analysis involving 171 participants GLPG1972/S201086 was shown to be well tolerated.

Objectives:

To present the study design of ROCCELLA, a large Phase 2 clinical trial in knee OA (KOA) patients, evaluating the efficacy and safety of GLPG1972/S201086 in reducing cartilage loss in OA.

Methods:

ROCCELLA is a multinational 52-week, multicentre randomized double-blind placebo-controlled dose-ranging phase 2 trial for the treatment of OA (NCT03595618). Eligible patients were aged 40–75 years with a diagnosis of primary femorotibial KOA, a pain score of 40–90mm on a 100 mm Visual Analogue Scale (VAS), predominant medial disease and a combined Kellgren/Lawrence (KL) 2 or 3 and Osteoarthritis Research Society International (OARSI) medial joint space narrowing (JSN) 1 or 2 severity grading range upon central reading of the X-ray. If both knees were eligible, the target knee was selected based first on the highest KL grade, then on the highest JSN grade and finally on the highest pain VAS score at baseline. Patients were randomized 1:1:1:1 to take placebo or three dose levels of GLPG1972/S201086 orally once daily for 52 weeks. The target knee was evaluated by quantitative Magnetic Resonance Imaging (qMRI) at baseline visit, week 28 and week 52, or at early withdrawal.

The primary endpoint of the study is change from baseline to week 52 in cartilage thickness of the central medial tibio-femoral compartment (cMTFC) of the target knee. Secondary objectives are safety and tolerability including treatment emergent serious adverse events. Additional secondary structural and clinical efficacy objectives are based on changes from baseline in the target knee: cartilage thickness and bone area on qMRI, KOA “progressor” rates, Joint Space Width on X-ray, pain VAS, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) total and sub scores, Patient Global Assessment VAS and the proportion of Outcome Measures in Rheumatology (OMERACT)-OARSI responders. Blood will be collected to assess the pharmacokinetics of GLPG1972/S201086. Planned, exploratory analyses include biochemical biomarkers of cartilage and bone turn-over. The study is designed to maintain the experiment wise type I error at 5%. A Mixed-effects Model for Repeated Measures will be used for the primary analysis. The randomisation was stratified by geographic region.

Results:

The study started in August 2018 and was fully recruited (N=938) by June 2019. Large numbers of patients with KOA had to be screened to meet the stringent pre-specified selection criteria. The study completion is expected by end of 2020.

Conclusion:

This is the first large Phase 2 study where patients with primary KOA are treated for 52 weeks with GLPG1972/S201086, an orally administered DMOAD candidate. This clinical trial was designed with a combination of two radiological selection criteria to ensure sufficient structural progression (cartilage loss) in the study population.

References:

[1]Durigova Met al.Osteoarthritis Cartilage2008;16:1245–52.

Acknowledgments:

This study was funded by Galapagos NV. Editorial support was provided by Oxford PharmaGenesis and funded by Galapagos NV.

Disclosure of Interests:

Henri Deckx Employee of: Galapagos, Ellen van der Aar Employee of: Galapagos, Marjolijne van der Stoep Employee of: Galapagos, Marianne Wooning Employee of: Galapagos NV, Katy Bernard Employee of: Institut de Recherches Internationales Servier, Sergey GRANKOV Employee of: Institut de Recherches Internationales Servier, Olivier Imbert Employee of: Institut de Recherches Internationales Servier, Maria Pueyo Employee of: Institut de Recherches Internationales Servier, Felix Eckstein Grant/research support from: Merck, Orthotrphix, Servier, Galapagos, Kolon Tissuegene, Samumed, Novartis, Consultant of: Merck, Bioclinica, Servier, Samumed, Roche, Kolon Tissuegene, Galapagos and Novartis, Employee of: co-owner and employment with Chondrometrics

FRI0393 BASELINE CHARACTERISTICS OF THE STUDY POPULATION IN ROCCELLA, A PHASE 2 CLINICAL TRIAL EVALUATING THE EFFICACY AND THE SAFETY OF S201086/GLPG1972 IN PATIENTS WITH KNEE OSTEOARTHRITIS

Background:

Osteoarthritis (OA) is a degenerative joint disease involving structural pathology of all joint tissues, and most commonly affecting the knee, hip and hand. Degradation of the cartilage extracellular matrix represents a central feature of OA and is widely thought to be mediated by proteinases that degrade primarily aggrecan and collagen. ADAMTS-5, a Disintegrin And Metalloproteinase with ThromboSpondin-motif-5, is a key aggrecan-cleaving enzyme involved in cartilage degradation. S201086/GLPG1972, a potent and highly selective inhibitor of ADAMTS-5, is an oral Disease-Modifying OsteoArthritis Drug (DMOAD) candidate.

Objectives:

The primary objective of the ROCCELLA phase 2 clinical trial (NCT03595618) is to evaluate the effect of S201086/GLPG1972 over 52 weeks of treatment (3 dose groups compared to placebo) in reducing cartilage loss. Cartilage thickness of the knee is being measured quantitatively by Magnetic Resonance Imaging. Here, we describe the baseline characteristics of patients included in the ROCCELLA clinical trial.

Methods:

The main inclusion criteria were: male or female, aged 40 to 75, with a diagnosis of knee OA according to the clinical and radiological criteria of the American College of Rheumatology. The target knee had to meet a pain score between 40 and 90 mm on a 100 mm Visual Analog Scale (VAS), and the following radiographic feature upon central radiographic readings: Kellgren/Lawrence (KL) 2 or 3 and OARSI medial joint space narrowing (JSN) 1 or 2 (for more details see Deckxet al. OARSI 2020). The rationale for these specific radiographic inclusion criteria was to ensure sufficient cartilage loss over 12 months to assess the efficacy of S201086/GLPG1972.

Results:

Across 12 countries, 3319 patients were screened and 932 were finally included in the study. The screen failure of 72% is mainly due to the radiological criteria. The age of the patients was 62.9 ± 7.3 years (mean ± SD) with a majority of women (69.3%). The BMI was 30.5 ± 4.7 kg/m2. The duration of knee OA was 7.2 ± 6.9 years. Five hundred and one (53.8%) patients reported a medical history of musculoskeletal and connective tissue disorders, mainly osteoarthritis in other sites (20.2%), back pain (13.6%), and arthralgia (9.8%). At inclusion, 97.2% of the patients were taking different types of drug treatments, mainly anti-inflammatory and anti-rheumatic products (69.4%) and analgesics (42%). At baseline, 11% of the target knees were KL2 and 89% were KL3; 32% were OARSI medial JSN grade 1 and 68% grade 2. Target knees at inclusion had a pain score on the VAS of 63.5 ± 11.4 mm (range 0-100, with 0 for no and 100 for extreme pain) and a total WOMAC (Likert 3.1) score of 48.0 ± 15.0 (range 0-96). The WOMAC subscores for pain, stiffness and physical function were 10.0 ± 3.2 (range 0-20), 4.2 ± 1.6 (range 0-8) and 33.8 ± 11.2 (range 0-68, indicating functional limitation), respectively.

Conclusion:

For this clinical trial, patients were selected to present radiological criteria (i.e.OARSI JSN 1 and 2) to ensure sufficient structural progression (cartilage loss) over 12 months, as well as clinical symptoms. These stringent selection criteria were the main cause for the high screen failure rate. These baseline characteristics should warrant the ability to evaluate the efficacy of S201086/GLPG1972 as a DMOAD candidate. The search for an effective pharmacological treatment that can prevent or cure OA remains a major challenge and unmet medical need.

Disclosure of Interests:

Katy Bernard Employee of: Institut de Recherches Internationales Servier, Sergey GRANKOV Employee of: Institut de Recherches Internationales Servier, Marjolijne van der Stoep Employee of: Galapagos, Agnès Lalande Employee of: Institut de Recherches Internationales Servier, Olivier Imbert Employee of: Institut de Recherches Internationales Servier, De Phung Employee of: Galapagos, Damien Chimits Employee of: Institut de Recherches Internationales Servier, Karine Muller Employee of: Galapagos, Ellen van der Aar Employee of: Galapagos, Henri Deckx Employee of: Galapagos, Maria Pueyo Employee of: Institut de Recherches Internationales Servier, Felix Eckstein Grant/research support from: Merck, Orthotrphix, Servier, Galapagos, Kolon Tissuegene, Samumed, Novartis, Consultant of: Merck, Bioclinica, Servier, Samumed, Roche, Kolon Tissuegene, Galapagos and Novartis, Employee of: co-owner and employment with Chondrometrics

FRI0411 SAFETY, TOLERABILITY, PHARMACOKINETICS AND PHARMACODYNAMICS IN HEALTHY MALE JAPANESE SUBJECTS OF THE ADAMTS-5 INHIBITOR S201086/GLPG1972, A POTENTIAL NEW TREATMENT IN OA

Background:

The disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5) is a key enzyme in OA (Verma P,et al.J Cell Biochem 2011;112:3507-14). In preclinical models of OA, S201086, a potent and selective ADAMTS-5 inhibitor, protects from cartilage degradation (Clement-Lacroix,et al.Osteoarthritis Cartilage 2017;25:S58). Therefore, S201086 is co-developed by Servier and Galapagos (GLPG1972) as a potential new treatment in OA.

Objectives:

This phase I study was to assess and compare the safety, tolerability, pharmacokinetics and pharmacodynamics of S201086 in healthy male Japanese and Caucasian subjects.

Methods:

Six ascending single doses of S201086 (50 to 1500 mg) were administered orally as tablets in fasting conditions in 6 groups of 8 Japanese subjects (aged 20-45 years) and 3 ascending multiple doses (300, 600 or 1050 mg/day for 14 days) were administered orally as tablets in fed conditions in 3 groups of 8 Japanese subjects. Additionally, 2 cohorts of 8 Caucasian subjects received either a single oral dose of 300 mg or repeated oral dose of 300 mg once daily for 14 days. In each group, 6 subjects received S201086 and 2 placebo. Plasma was collected at several time points for the quantification of S201086 by LC-MS/MS. Plasma pharmacokinetic parameters were calculated via non-compartmental analysis using Phoenix® WinNonlin® software. Pharmacodynamics was assessed by measurement of the aggrecan ARGS neoepitope levels in serum by ELISA.

Results:

No serious adverse drug reactions were observed after administration of single and multiple ascending doses of S201086 in either Japanese or Caucasian subjects. Most adverse events were of mild to moderate intensity and were resolved by the end of the study. Following single administration to Japanese subjects, Cmax and AUC increased proportionally with doses from 50 to 600 mg and slightly less than dose-proportionally from 600 to 1500 mg, consistent with what was previously observed in the first in-human study in healthy Caucasian subjects (van der Aar E,et al.Osteoarthritis Cartilage 2018;26:S310). In Japanese subjects, after 14-days administration, a limited 1.2- to 1.4-fold accumulation was observed on both Cmax and AUC at Day14 as compared to Day1, and the steady-state exposure increased dose-proportionally within the 300-1050 mg dose range. Taking the inter-subject variability into account, no difference was observed in Cmax and AUC between Caucasian and Japanese subjects after single administrations of 300 mg and repeated administrations of 300 mg once daily for 14 days. The serum ARGS neoepitope levels decreased between baseline and last day of treatment for S201086-treated subjects but not for subjects receiving placebo. This decrease was similar for the 3 tested doses in Japanese subjects and was significant as compared to the placebo-treated subjects.

Table.

Comparison of ARGS concentration relative change from baseline to last day of treatment according to dose in Japanese participants

S 201086 300 mg (N = 6)S 201086 600 mg (N = 6)S 201086 1050 mg (N = 6)Placebo (N = 6)Descriptive Statistics(D14 pre-dose – Baseline) / Baselinen6646Mean ± SD-42.67 ± 8.81-53.70 ± 6.50-54.11 ± 5.2013.35 ± 16.53Statistical analysisE (SE)56.01 (6.156)67.04 (6.156)67.45 (6.883)95% CI43.08; 68.9554.11; 79.9752.99; 81.91p-value< 0.0001< 0.0001< 0.0001

Conclusion:

S201086 was shown to be safe and well-tolerated in Japanese and Caucasian healthy male subjects with a suitable PK profile and a significant decrease of the ARGS neoepitope, indicating target engagement. A global Phase 2 study to evaluate the efficacy of S201086 in patients with knee OA is ongoing (NCT03595618).

Disclosure of Interests:

Agnès Lalande Employee of: Institut de Recherches Internationales Servier, Nadya KUZNIATSOVA-MOUCHETTE Employee of: Institut de Recherches Internationales Servier, Florian CHASSEREAU Employee of: Institut de Recherches Internationales Servier, Julia GERONIMI Employee of: Institut de Recherches Internationales Servier, Katy Bernard Employee of: Institut de Recherches Internationales Servier, Staffan Larsson: None declared, André Struglics: None declared, Stefan Lohmander: None declared, Maria Pueyo Employee of: Institut de Recherches Internationales Servier

High ultrasensitive serum C-reactive protein may be related to freezing of gait in Parkinson's disease patients

C-reactive protein (CRP) is a biomarker of systemic inflammation that has been linked to accelerated decline in walking speed in older adults. The aim of the present study was to compare the CRP levels of PD patients with vs patients without freezing of gait (FOG). Patients and controls participating in the COPPADIS-2015 study that performed blood extraction for determining molecular serum biomarkers were included. Patients with FOG were identified as those with a score of 1 or greater on item-3 of the Freezing of Gait Questionnaire (FOG-Q). Immunoassay was used for determining ultrasensitive CRP (US-CRP) level (mg/dL). In the PD group (n = 225; 61.8 ± 9.5 years old, 61.8% males), 32% of the patients presented FOG but none in the control group (n = 65; 60.3 ± 6.1 years old, 56.9% males) (p < 0.0001). Differences in US-CRP level were significant in patients with FOG vs patients without FOG and vs controls (0.31 ± 0.52 vs 0.16 ± 0.21 vs 0.21 ± 0.22; p = 0.04). Significant differences were also observed between patients with vs without FOG (p = 0.001) but not between patients and controls (p = 0.163). US-CRP level was related to FOG (OR = 4.369; 95% CI 1.105-17.275; p = 0.036) along with H&Y (OR = 2.974; 95% CI 1.113-7.943; p = 0.030) and non-motor symptoms burden (NMSS total score; OR = 1.017; 95% CI 1.005-1.029; p = 0.006) after adjusting for age, gender, disease duration, equivalent daily levodopa dose, number of non-antiparkinsonian drugs per day, motor fluctuations, cognition, motor phenotype, and chronic use of anti-inflammatory drugs. The present study suggests that serum US-CRP level is related to FOG in PD patients. Inflammation could be linked to FOG development.

The ROSAS Cohort: A Prospective, Longitudinal Study of Biomarkers for Alzheimer's Disease. Strategy, Methods and Initial Results

OBJECTIVE

The aims of the Research Of biomarkers in Alzheimer's diseaSe (ROSAS) study were to determine the biofluid and imaging biomarkers permitting an early diagnosis of Alzheimer's disease and better characterisation of cognitive and behavioural course of the pathology. This paper outlines the overall strategy, methodology of the study, baseline characteristics of the population and first longitudinal results from the ROSAS cohort.

METHODS

Longitudinal prospective monocentric observational study performed at the Alzheimer's disease Research centre in Toulouse. A total of 387 patients were studied and analyzed in 3 groups: 184 patients with dementia of Alzheimer's type, 96 patients with memory disorders without dementia (Mild Cognitive Impairment) and 107 patients without abnormal memory tests (control group), and were followed up during 4 years. Patient's sociodemographic characteristics, risk factors, medical conditions, previous and current medications, neuropsychological assessment and overall cognitive status were recorded. Blood and urine samples were collected at every year, Magnetic Resonance Imaging were performed at inclusion, after one year of follow-up and at the end of the study.

RESULTS

At baseline, three different groups of the cohort differed interestingly in age, level of education, and in percentage of ApoEε4 carriers whereas the history of cardiovascular and endocrine pathologies were similar among the groups. During the follow-up period (3-4 years) 42 mild cognitive impairment patients (43.8%) progressed to dementia, 7 controls progressed into mild cognitive impairment and 1 patient in the control group converted from mild cognitive impairment group to dementia of Alzheimer's type group. During the first year of follow up, the incidence of progression from mild cognitive impairment to dementia of Alzheimer's type was 12.7 per 100, during the second year 33.9 per 100 and 46.7 per 100 for the third year.

CONCLUSION

This paper presents the baseline characteristics of the unique French prospective monocenter study in which the natural course of dementia of Alzheimer's type was evaluated. Future analysis of blood and urine samples collection from the ROSAS study will permit to identify possible biofluid biomarkers predicting the early stages of the dementia of Alzheimer's type and risk of progression from Mild Cognitive Impairment to Alzheimer's disease.

Diode Laser Photocoagulation in Retinopathy of Prematurity

We used diode laser photocoagulation to treat 22 eyes of 12 patients with retinopathy of prematurity. Three infants were followed for at least six months and nine for at least one year. We treated 14 eyes with threshold disease and 8 eyes with prethreshold disease. The treatment was administered within 72 hours of diagnosis and topical anesthesia and sedation were used. No evidence of lesions of the anterior segment of preretinal or vitreous hemorrhages was found after the treatment. External inflammatory signs were neglibible. Systemic complications occurred only in three treatment sessions. Eight of the 14 eyes with threshold disease (57%) and all eight eyes with prethreshold disease had favorable outcomes. In total 73% with ROP had favorable outcomes. Treatment with the diode laser is easily performed, effective essentially in cases of prethreshold disease but in threshold disease too, with minimal ocular or systemic complications.

Long-Term Effects of Postoperative Subconjunctival Injections of Mitomycin-C in the Rabbit Eye

Aim

Single or multiple subconjunctival injections of mitomycin-C (MMC) may offer one way of establishing the total dosage of MMC more accurately. The method also allows re-applications later postoperatively. In this experimental, randomized prospective study we compared the effects of a single intraoperative application of MMC at the filtering site and a single postoperative subconjunctival injection of the drug.

Methods

The left eyes of 32 pigmented rabbits were divided into two groups. In the first group we applied MMC intraoperatively (10) with a 4×1 mm surgical sponge soaked in a MMC solution (0.5 mg/ml). In the second group we injected 0.4 ml of the same solution subconjunctivally (SC) immediately after (conjunctival) suture. Post-operative evaluation was carried out every day during the first week, then every three days until day 58. Survival analyses were done for intraocular pressure (IOP) and bleb failure. Log-rank tests were used to compare survival differences between the groups.

Results

The IO group showed longer survival parameters than the SC group (p<0.05), both in the control of IOP and as regards blebs. The histological persistence of fistulas was similar. The IO group, however, had a higher incidence of undesirable side effects.

Conclusions

Our findings suggest IO application of MMC is more effective in reducing fibroblast ingrowth. However, subconjunctival application offers certain advantages such as the possibility of repeating the treatment postoperatively and, therefore, using a smaller initial dose.

Use of the modified BCR three-step sequential extraction procedure for the study of trace element dynamics in contaminated soils

The modified BCR three-step sequential extraction procedure was used to examine the temporal dynamics of trace elements in soils contaminated by an accidental spill from an opencast mine in south-west Spain. Soils were mainly contaminated with pyritic sludge and acidic wastewater, whereas some soils were affected only by acidic wastewater. The distributions obtained for both some major (Ca, Fe and Mn) and trace elements (As, Cd, Cu, Pb and Zn) in the sludge and soil samples taken at different times after the accident, 1-3 months and 21 months, were compared. Sequential extractions were useful in identifying different sources of contamination, and in obtaining additional information on the solubility of secondary minerals formed by pyrite oxidation. Thus, the effectiveness of the BCR procedure has proved to be a useful tool for predicting short- and long-term mobility of trace elements, even in complex environmental scenarios.

[Night blindness and xerophthalmia after surgery for morbid obesity]

CASE REPORT

We describe ocular findings due to a vitamin A deficiency in a 50-year-old man. The patient had undergone intestinal bypass surgery two years before. After therapy with oral vitamin A the symptoms improved.

DISCUSSION

The incidence of morbid obesity is increasing throughout much of the developed world, with intestinal bypass surgery the treatment of choice for most people with the condition. This type of surgery can lead to a vitamin A deficiency, with remarkable ophthalmological consequences, which without correct treatment may ultimately cause blindness. For this reason, the pathology, even though rare at present, must considered seriously.

Prediction of trace element mobility in contaminated soils by sequential extraction

The modified three-step sequential extraction procedure proposed by the Community Bureau of Reference (or Bureau Communautaire de Reference, BCR) was used to predict trace element mobility in soils affected by an accidental spill comprising arsenopyrite- and heavy metal-enriched sludge particles and acid waste waters. The procedure was used to obtain the distribution of both the major (Al, Ca, Fe, Mg, and Mn) and trace elements (As, Bi, Cd, Cu, Pb, Tl, and Zn) in 13 soils of contrasting properties with various levels of contamination and in the sludge itself. The distributions of the major elements enabled us to confirm the main soil fractions solubilized in each of the three steps, and, in turn, to detect the presence of pyritic sludge particles by the high Fe extractability obtained in the third step. Cadmium was identified as being the most mobile of the elements, having the highest extractability in the first step, followed by Zn and Cu, Lead, Tl, Bi, and As were shown to be poorly mobile or nonmobile. In the case of some of the trace elements, the residual fractions decreased at higher levels of contamination, which was attributed to the anthropogenic contributions to the polluted samples. Comparison with soil-plant transfer factors, calculated in plants growing in the affected area, indicated that a relative sequence of trace element mobility was well predicted from data of the first step.

Certification of the extractable contents of Cd, Cr, Cu, Ni, Pb and Zn in a freshwater sediment following a collaboratively tested and optimised three-step sequential extraction procedure

Sequential extraction procedures have been used during the last decades to study and determine trace element mobility in aquatic sediments. However, the results obtained are operationally defined and, therefore, the significance of the analytical results is related to the extraction scheme used. So, there is a need for suitable reference materials for this type of study to enable the validation of the methodologies and to control the quality of the measurements. This paper describes the preparation of a sediment reference material, BCR-701, the homogeneity and stability studies and the analytical work performed for the certification of the extractable contents of some trace elements, following a collaboratively tested and optimised sequential (three-step) extraction procedure. The paper contains all the results and gives the methods used to certify the extractable contents (mass fractions expressed as mg kg-1 on a dry matter basis) of Cd, Cr, Cu, Ni, Pb and Zn in all steps. Moreover, indicative values are given for the aqua regia extractable contents of the six elements in the sediment and the residue obtained after sequential extraction.

[Ciliary ablation with diode laser. Long-term study]

PURPOSE

The effects of contact transscleral cyclophotocoagulation with diode laser for refractory glaucoma have been analyzed.

METHODS

A diode laser system was used to treat twenty one eyes with refractory glaucoma. The mean follow-up was 22.24+/-9.89 months. All the eyes were treated with 15 laser spots placed over 270 degrees, 1 mm posterior to the limbus, using 3.0 J (1.0 W X 3.0 sg).

RESULTS

The mean preoperative intraocular pressure was 40.95+/-11.76 mmHg and the mean intraocular pressure at the end of the follow-up was 24.28+/-7.80 mmHg (p<0.5). An intraocular pressure below 21 mmHg was obtained in 10 out the 13 eyes (76.92%). Six of the 8 painful eyes had pain relief (75.00%). The principal complications included a decreased visual acuity in 5 eyes and chronic uveitis in 2 patients.

CONCLUSIONS

These results suggest that semiconductor diode transscleral cyclophotocoagulation can be used successfully to reduce intraocular pressure in the treatment of refractory glaucoma.

A new organic-rich soil reference material certified for its EDTA- and acetic acid- extractable contents of Cd, Cr, Cu, Ni, Pb and Zn, following collaboratively tested and harmonised procedures

There is an increasing requirement for assessment of the bioavailable metal fraction and the mobility of trace elements in soils upon disposal. One of the approaches is the use of leaching procedures, but the results obtained are operationally defined; therefore, their significance is highly dependent on the extraction protocol performed. So, for this type of study, there is a need for reference materials that allow the quality of measurements to be controlled. This paper describes the steps involved in the certification of an organic-rich soil reference material, BCR-700, for the EDTA- and acetic acid-extractable contents of some trace elements, following collaboratively tested and harmonised extraction procedures. Details are given for the preparation of the soil, homogeneity and stability testing, analytical procedures and the statistical selection of data to be included in the certification.

Endothelium-derived nitric oxide and vascular physiology and pathology

In 1980, Furchgott and Zawadzki demonstrated that the relaxation of vascular smooth muscle cells in response to acetylcholine is dependent on the anatomical integrity of the endothelium. Endothelium-derived relaxing factor was identified 7 years later as the free radical gas nitric oxide (NO). In endothelium, the amino acid L-arginine is converted to L-citrulline and NO by one of the three NO synthases, the endothelial isoform (eNOS). Shear stress and cell proliferation appear to be, quantitatively, the two major regulatory factors of eNOS gene expression. However, eNOS seems to be mainly regulated by modulation of its activity. Stimulation of specific receptors to various agonists (e.g., bradykinin, serotonin, adenosine, ADP/ATP, histamine, thrombin) increases eNOS enzymatic activity at least in part through an increase in intracellular free Ca2+. However, the mechanical stimulus shear stress appears again to be the major stimulus of eNOS activity, although the precise mechanisms activating the enzyme remain to be elucidated. Phosphorylation and subcellular translocation (from plasmalemmal caveolae to the cytoskeleton or cytosol) are probably involved in these regulations. Although eNOS plays a major vasodilatory role in the control of vasomotion, it has not so far been demonstrated that a defect in endothelial NO production could be responsible for high blood pressure in humans. In contrast, a defect in endothelium-dependent vasodilation is known to be promoted by several risk factors (e.g., smoking, diabetes, hypercholesterolemia) and is also the consequence of atheroma (fatty streak infiltration of the neointima). Several mechanisms probably contribute to this decrease in NO bioavailability. Finally, a defect in NO generation contributes to the pathophysiology of pulmonary hypertension. Elucidation of the mechanisms of eNOS enzyme activity and NO bioavailability will contribute to our understanding the physiology of vasomotion and the pathophysiology of endothelial dysfunction, and could provide insights for new therapies, particularly in hypertension and atherosclerosis.

[Effects of angiotensin ii on vascular remodeling]

Classically the AT1 receptors to angiotensin II are considered to be present on the smooth muscle cell membrane in the arterial wall, in which they diffusely regulate peripheral resistances. They are also present on numerous other cell types, including fibroblasts and myofibroblasts, monocytes and macrophages, endothelial cells, where they participate to the phenotypic modulation of the cell, involved in their activation leading to tissular remodeling. The intra-cellular pathway involving the phospholipase C activation and the mobilization of intra-cellular calcium is predominantly involved in the functional vasomotor response to angiotensin II. In contrast the intra-cellular signaling pathway leading to production of oxygen free radicals and activation of the NF-kappa-B system is probably mainly involved in the phenotypic modulation of target cells and their consequences on the vascular tissue remodeling.

Semiconductor diode laser transscleral cyclophotocoagulation versus filtering surgery with Mitomycin-C

Both filtering surgery with Mitomycin-C and diode laser cyclophotocoagulation have proved to be effective alternatives in cases of glaucoma with poor surgical prognosis. The right eyes of 40 pigmented rabbits were randomly divided into 2 groups: Mitomycin-C group underwent filtering surgery with application of 0.4 mg/ml of Mitomycin-C whereas the diode laser (DL) group received 15 applications of 1.8 J (1800 mW. 1000 ms) distributed in 270 degrees. Mean IOP showed statistical differences in two periods between days 3-13 and 45-60-Mann-Whitney U test -with a higher IOP lowering in the DL group. The comparison of IOP survival curves (Log-Rank test) was not significant p = 0.070809. Ocular hypertension, hyphema and inflammatory signs were higher in the DL group, both in short and long term, but in terms of statistical significance only ocular hypertension showed differences p = 0.00011717-Fisher exact test. Microscopic examination revealed patent sclerostomies in 60% of the MMC group eyes with different grades of fibroblastic proliferation. In the DL group we observed necrosis of the scleral stroma and of the pigmented and unpigmented ciliary epithelium, with signs of thermal coagulation of the ciliary stroma and of the stromal vasculature. We must point out that the treatment with laser has proved to be more effective although both treatments showed very acceptable IOP lowering until 2 months after the surgery.

Assessment of diurnal tensional curve in early glaucoma damage

We know very little about the relationship between the diurnal intraocular pressure variations and the progression of visual field loss. A prospective study of 149 eyes of 149 patients suffering from intraocular hypertension has been carried out through a minimum period of five years. At least 4 years before the appearance of field defects, we detected significant oscillations of IOP in the 64% of the cases prone to develop visual field loss. Likewise, we have found a statistically significant relationship between the presence of defects in the RNFL (retinal nerve fiber layer) and the existence of significant oscillations of IOP.

Relationship between the functional regions of the RecA protein and ATP hydrolysis in UV-irradiated Escherichia coli cells

The time course of the intracellular ATP concentration in several UV-irradiated RecA protease constitutive (Cptc) mutants of E. coli has been studied. All Cptc mutants harboring a mutation in region 3 of the RecA protein (including amino acid residues 298-301) increased ATP after UV damage but without any subsequent decrease. Nevertheless, these mutants induced the SOS response after UV irradiation. Likewise, truncated RecA proteins lacking region 3 are also unable to carry out massive ATP hydrolysis in UV-irradiated cells. On the other hand, mutants in region 1 (including amino acids 25-39) or 2 (amino acids 157-184) of the RecA protein showed an increase in ATP concentration during the first 20 min following UV irradiation, which dropped afterwards to the basal level. All these data indicate that region 3 of the RecA protein must be involved in the ATP hydrolysis process. Furthermore, a relationship between the quantity of the UV-mediated ATP produced and the strength of the different RecA Cptc mutants has also been found. Accordingly, both lexA71::Tn5 and null lexA mutants of E. coli only show a cellular ATP increase after UV irradiation when containing a multicopy plasmid carrying either a wild-type lexA or a lexA (Ind-) gene.