Subchondral involvement in osteonecrosis of the femoral head: insight on local composition, microstructure and vascularization

OBJECTIVE

To determine changes of subchondral bone composition, micro-structure, bone marrow adiposity and micro-vascular perfusion in end-stage osteonecrosis of the femoral head (ONFH) compared to osteoarthritis (OA) using a combined in vivo and ex vivo approach.

DESIGN

Male patients up to 70 years old referred for total hip replacement surgery for end-stage ONFH were included (n = 14). Fifteen patients with OA were controls. Pre-operative MRI was used to assess bone perfusion (dynamic contrast-enhanced (DCE) sequences) and marrow fat content (chemical shift imaging). Three distinct zones of femoral head subchondral bone - necrotic, sclerotic, distant - were compared between groups. After surgery, plugs were sampled in these zones and Raman spectroscopy was applied to characterize bone mineral and organic components (old and newly-formed), and contrast-enhanced micro-computed tomography (CE-μCT) to determine bone micro-structural parameters and volume of bone marrow adipocytes, using conventional 2D histology as a reference.

RESULTS

In the necrotic zone of ONFH patients compared to OA patients: 1) the subchondral plate did not exhibit significant changes in composition nor structure; 2) the volume fraction of subchondral trabecular bone was significantly lower; 3) type-B carbonate substitution was less pronounced, 4) collagen maturity was more pronounced; and 5) bone marrow adipocytes were significantly depleted. The sclerotic zone from the ONFH group showed greater trabecular thickness, and higher DCE-MRI AUC and K_trans. Volume fraction of subchondral bone, trabecular number, and K_ep were significantly lower in the distant zone of the ONFH group.

CONCLUSIONS

This study demonstrated alterations of subchondral bone microstructure, composition, perfusion and/or adipose content in all zones of the femoral head.

T1-weighted MRI images accurately represent the volume and surface of architectural mineral damage of osteonecrosis of the femoral head: Comparison with high-resolution computed tomography

The potency of magnetic resonance imaging (MRI) to measure the exact extent of osteonecrosis of the femoral head (ONFH) remains uncertain. The objective of this study was to determine if the volume of necrosis assessed with MRI accurately reflects the volume of architectural mineral alterations in osteonecrosis of the femoral head by comparison with high-resolution microfocus X-ray computed tomography (HR-μCT). Fourteen male patients aged 53 years [46.2;59.0] suffering from ONFH were prospectively enrolled to undergo preoperative MRI and ex vivo analysis using HR-μCT. The necrotic zone on T1-weighted MRI scans was defined as total necrosis (delimited by the low-signal peripheral band) or dark necrosis (low-signal lesions only). The HR-μCT scans delimited outer necrosis and inner necrosis by including or excluding the sclerotic zone. The intra-class correlation coefficient (ICC) was calculated to compare the agreement of surface areas and volumes of necrosis measurements with the two techniques. There was an overall excellent agreement between MRI dark necrosis volume and HR-μCT outer necrosis volume (ICC=0.91[0.54;0.98]) while the MRI total necrosis volume showed poor agreement with both HR-μCT delimitations of necrosis volume. For surface area, agreement between MRI dark necrosis and HR-μCT delimitations was good for inner necrosis (ICC=0.70[0.21;0.9]) and moderate for outer necrosis (ICC=0.58[0.07;0.85]). This study demonstrates that measurement of the MRI lesions provides a reliable assessment of the extent of ONFH-related architectural damage.

Simple Method for Quantifying Alpha-Tocopherol in Low-Density+Very-Low-Density Lipoproteins and in High-Density Lipoproteins

We assessed the distribution of alpha-tocopherol in serum lipoprotein samples after separating the lipoprotein fractions by either sequential ultracentrifugation or selective precipitation with sodium phosphotungstate-magnesium chloride reagent. alpha-Tocopherol concentrations were determined by reversed-phase high-performance liquid chromatography. After ultracentrifugation, we found that in men, low- and very-low-density serum lipoproteins (LDL-VLDL) contained 53.6% of alpha-tocopherol vs 46.4% in high-density lipoproteins (HDL). In women, serum LDL-VLDL contained 45.6% alpha-tocopherol after ultracentrifugation vs 54.4% in HDL. After selective precipitation, the proportions of alpha-tocopherol in men were 56.1% in LDL-VLDL vs 43.9% in HDL, and in women, 45.4% in LDL-VLDL vs 54.6% in HDL. After selective precipitation, alpha-tocopherol recovery from whole lipoprotein fractions was 97% to 100% vs 80% after ultracentrifugation, thus allowing more accurate alpha-tocopherol quantification than after separation by ultracentrifugation.

P05.05 Safety and feasibility of temporary blood-brain barrier disruption with the SonoCloud-1/3 implantable ultrasound device in recurrent glioblastoma

BACKGROUND

The blood-brain barrier (BBB) limits penetration of drug therapies to the brain and may account for the limited effectiveness of chemotherapies in patients with primary brain cancer. An implantable ultrasound (US) device, SonoCloud, was developed to temporarily disrupt the BBB in patients with recurrent glioblastoma (rGBM) prior to carboplatin chemotherapy administration to enhance brain drug concentrations. BBB disruption was investigated with a single emitter device, SonoCloud-1 (SC1) and a three-emitter device, SonoCloud-3 (SC3) in a safety and feasibility study in rGBM patients at the Hôpitaux Universitaires La Pitié Salpêtrière in Paris, France (NCT02253212).

MATERIAL AND METHODS

The SC1 implant consisted of a 1 MHz, 10-mm diameter ultrasound transducer encapsulated in a biocompatible housing while the SC3 consisted of (3) separate SC1 emitters implanted in a triangular pattern to disrupt the BBB over a 3x larger volume. Patients were implanted with the SonoCloud device during tumor debulking or in a dedicated surgical procedure. The devices were activated monthly by connecting the device to an external generator via a transdermal needle. Intravenous injection of SonoVue® microbubbles was performed with device activation to temporarily disrupt the BBB. Magnetic resonance imaging (MRI) was performed after sonications with gadolinium contrast to verify BBB disruption followed by carboplatin infusion at AUC4-6. Patients received treatments until disease progression.

RESULTS

Between 2014 and 2016, 21 patients were registered for the study and implanted with the SC1; 19 patients received at least one sonication. Six additional patients were implanted and received sonications with the SC3. A total of 89 US sessions were performed to disrupt the BBB - 65 with the SC1 and 24 with the SC3. Treatment-related adverse events observed were transient and manageable. No carboplatin-related neurotoxicity was observed. SC1 patients with no or poor BBB disruption (n=8) visible on MRI had a median progression-free survival (PFS) of 2.73 months, and a median overall survival (OS) of 8.64 months. SC1 patients with clear BBB disruption (n=11) had a median PFS of 4.11 months, and a median OS of 12.94 months. The SC3 device was as well-tolerated as the SC1 device, with SC3 patients receiving between 1–12 monthly sonications.

CONCLUSION

These results provide the first safety data on the effects of disrupting the BBB in rGBM patients prior to carboplatin chemotherapy using an implantable low intensity pulsed ultrasound device on enlarged areas of brain. This study has now been completed. A new safety study with a larger device, SonoCloud-9, that covers the tumor and surrounding infiltrative regions, has started in France in early 2019 (NCT03744026). Work supported by CarThera and APHP.

OS4.3 Feasibility and benefit of Molecular Profiling to Guide Enrollment of Patients with Recurrent Gliomas in Early Phase Trials

BACKGROUND

Participation of glioma patients in early phase clinical trials has recently shown to be safe, although clinical benefits reported in this population were marginal. We aimed to evaluate whether an enrichment strategy based on molecular profiling associates with improved outcome in gliomas patients participating in early phase trials.

MATERIAL AND METHODS

Records of patients enrolled in early phase trials of cytotoxic therapies, small molecule inhibitors or monoclonal antibodies from 2008 to 2017 were analyzed for clinicopathological characteristics, toxicity, response, median progression-free survival (PFS) and overall survival (OS). The primary objective was to evaluate the feasibility and benefit of using molecular profiling to guide enrollment.

RESULTS

Ninety-one patients were enrolled, of whom 47/91 (51.6%) were molecularly oriented. Molecular targets included IDH1/2 (n=15) and BRAF (11) mutations, FGFR1-3 fusions (n= 10) and mutations (n = 4), mismatch repair deficiency (8), and MDM2 amplification (1). Grade 3/4 adverse events were reported in 9/91 (9.9%) patients. In patients with IDH1/2-wild-type high-grade glioma (n=45), the overall response rate (24.0% [95% CI 11.5–43.4] vs 0.0% [95% CI 0.0–16.1], P=0.027) was significantly higher in molecularly-oriented vs non-molecularly-oriented patients. Updated outcome results, and clinical and molecular factors associated with response, PFS and OS in multivariate analyses will be presented at the conference.

CONCLUSION

Using molecular profiling to guide enrollment in early phase trials is feasible and offers potential benefit to gliomas patients. Further studies are warranted to identify the population most likely to benefit from this approach.

OS9.7 Telomere length, TERTp mutation and ALT status in adult diffuse gliomas

BACKGROUND

The current classification of adult diffuse gliomas integrates two alternative telomere maintenance mechanisms: reactivation of telomerase activity by TERT promoter (TERTp) mutations or ATRX mutations associated with alternative length telomere (ALT). We investigated here the relation between these two mechanisms, telomere length, and outcome in a large series of diffuse gliomas.

MATERIAL AND METHODS

We performed C-circle assay (CCA) to determine ALT status, determined telomere length in tumor (RTLt) and leukocyte (RTLl) in a cohort of 354 adult diffuse gliomas, and sequenced ATRX gene. We calculated an age-adjusted telomere score considering tumor and leukocyte (blood) telomere length and corrected by age. This score was used in univariate and multivariate survival analyses to evaluate the potential impact of telomere length on the prognosis of gliomas. We used the TCGA LGG-GBM dataset to validate our findings in an independent cohort.

RESULTS

RTLl and RTLt were associated with ATRX mutation and ALT phenotype, and negatively associated with age and TERTp mutations. ATRX mutations (found in 52% (64/123) of samples) were mostly transitions (C>T or T>C), and were associated with ALT phenotype. None of 1p/19q co-deleted oligodendrogliomas harbored an ALT phenotype. No patients with TERTp mutations had ALT phenotype except for a very small subgroup of patients (3/87, 3.4%) suggesting that multiple ways of telomere maintenance, may co-exist in a single tumor, probably expressed in different clones. Telomere age-adjusted score was independently associated with better outcome (HR= 0.73 [95% CI 0.56–0.97], p-value 0.03 adjusted for age, TERTp mutation, IDH mutation, 1p/19q co-deletion and WHO grade). These results were validated using the LGG-GBM TCGA dataset.

CONCLUSION

We unravel the relation between RTLl and RTLt, TERTp mutation and ALT phenotype and describe a novel telomere age-adjusted score independently associated with better prognosis in adult diffuse gliomas.

P04.10 IDH-wildtype low grade gliomas: overall survival and prognostic indicators

BACKGROUND

IDH-wildtype WHO grade II diffuse gliomas represent a rare subgroup of low grade tumors characterized by poor prognosis. The clinical and molecular profile associated with these tumors has not been fully elucidated yet, and the ongoing uncertainties regarding their biological behavior hamper to establish a standard of treatment. The aim of this study is to define the median overall survival and the main prognostic factors associated with this rare tumor entity.

MATERIALS AND METHODS

We performed a retrospective research in our center for all patients diagnosed with diffuse WHO grade II and III gliomas from 1976 to 2018. WHO grade II and III gliomas were divided into three molecular subgroups according to the IDH1/2 mutation and the 1p/19q codeletion status (1: IDH-mutant, 1p/19q codeleted; 2: IDH-mutant, 1p/19q non codeleted; 3: IDH-wildtype). We analyzed the clinical and molecular characteristics of the three subgroups, and then the clinical, radiological, histological and molecular features of IDH-wildtype WHO grade II gliomas.

RESULTS

We identified 445 patients with diffuse WHO grade II gliomas, including 59 IDH1/2-wildtype tumors. IDH-wildtype grade II gliomas affected more frequently male (75% vs. 55%, p = 0.004) and older (mean age: 50.0 vs. 39.6 years, p<0.0001) patients, had frequent fronto-temporo-insular location (41%) and commonly underwent biopsy (53%) rather than resection. We found TERT promoter mutations (18/42, 43%), chromosome 7q gains (12/30, 40%), chromosome 10q losses (12/44, 27%), chromosome 9p losses (7/47, 15%), EGFR amplifications (5/51, 10%) and p16 deletions (4/50, 8%) but no P53 (0/16) mutations. Median overall survival was 46 months (vs. 98 for IDH-mutant non codeleted and 175 for IDH-mutant codeleted WHO grade II gliomas (p<0.0001); vs. 20 months for IDH-wildtype WHO grade III gliomas (p = 0.001)). Survival was not significantly influenced by age, preoperative KPS, tumor location, extent of resection or adjuvant treatment schemes. Chromosome 9p loss had a strong negative impact on overall survival (p=0.002).

CONCLUSION

The median overall survival associated with IDH-wildtype WHO grade II gliomas does not exceed 4 years from diagnosis. As some genetic alterations seem to have a strong prognostic impact, an exhaustive genetic assessment can be helpful in this rare tumor group for purposes of prognostic stratification and treatment decision.

P14.102 Cerebellar atrophy patterns in paraneoplastic cerebellar degeneraiton and spinocerebellar ataxia 1 (SCA1)

BACKGROUND

Brain and more specifically cerebellar atrophy is a major radiological finding in both Paraneoplastic Cerebellar Degeneration (PCD) with anti-Yo antibodies and Spinocerebellar Ataxia type 1 (SCA1).We sought to analyze the different brain volumetric patterns of cerebellar atrophy in these diseases.

MATERIAL AND METHODS

We performed a retrospective multicentric study (Paris, Lyon, Barcelona reference centres) with either anti-Yo PCD (n=16) or SCA1 (n=17) and 30 healthy subjects paired by age. We used VolBrain and CERES algorithms to obtain the brain and cerebellum segmentation, respectively as well as the cortical thickness. We used a Sparse Canonical Correlation Analysis (SCCAN) and Voxel Brain Morphometry (VBM) with family wise error correction to analyze volumetric differences between the different conditions.

RESULTS

SCA patients were younger than PCD patients (p<0.05, ANOVA). In univariate analysis, most of the atrophic regions (p<0.05) were common between PCD and SCA1 compared to controls. Isolated cortical thickness and grey matter analysis showed predominant atrophy in PCD patients. Multivariate analysis using SCCAN and VBM confirmed these results. We identified a particular atrophy pattern in PCD patients involving lobules III to VII. We observed a more diffuse atrophy distribution in SCA1 patients and a lower cortical atrophy in PCD patients.

CONCLUSION

We described the specific pattern of topographic cerebellar atrophy in PCD and SCA1 patients. The cerebellar atrophy in PCD is mainly localized in the neocerebellum.

OS9.2 Radiomics analysis of lower-grade gliomas, a POLA Network study

BACKGROUND

Lower-grade gliomas (LGG) are divided into three histo-molecular groups: i) IDH-wildtype, ii) IDH mutant and 1p19q intact and iii) IDH mutant and 1p19q co-deleted. The current classification has improved the clinical stratification and its reproducibility. However, LGGs are still associated with an important degree of clinical heterogeneity. We sought to analyze the cross-talk between the spatial distribution and the quantitative imaging features (radiomics) with the clinical evolution and their molecular background (radiogenomics).

MATERIAL AND METHODS

We performed a retrospective multicentric study from 4 cohorts of high-grades gliomas (POLA Network, TCGA, REMBRANDT and LGG-1p19q), totaling 900 gliomas. We performed N4 and WhiteStripe imaging corrections to standardize MRI intensities. We used ITK-SNAP to obtain a mask of the different habitats of the tumor. Then we used PyRadiomics to obtain 2616 radiomic features per sample. We used plsRcox for fitting several Cox model in high-dimensional settings. We assessed the performance of the difference Cox model with the Harrel’s concordance index. We used a Sparse Canonical Correlation analysis to analyze the spatial distribution of the tumors.

RESULTS

Radiomics features allow identification in an unsupervised manner IDH-mutant gliomas with a median AUC of 0.96 [0.92–0.98]. Interestingly, in the analysis of survival, radiomics features provided additional information to clinical or genetics covariates and the model with only radiomics features obtained a C-Index of 0.78 [0.72–0.82]. In addition, survival model with the best performance in the prediction of overall survival was the one combining radiomics, clinics and genetics features with a C-Index 0.85 [0.82–0.92] and was validated in the other cohorts. The analysis of spatial distribution showed a very strong distribution of 1p19q co-deleted oligodendrogliomas in the frontal lobes.

CONCLUSION

Radiomics features may provide additional relevant clinical information by improving the prognosis of LGG. Radiomics allow non-invasive prediction of the most relevant molecular alterations of LGG.

P04.12 Characteristics of IDH-mutant gliomas with non-canonical IDH mutations

BACKGROUND

About 10% of IDH-mutant gliomas harbor non-canonical IDH mutations (non-R132H IDH1 and IDH2 mutations). The aim of the present study was to analyze the characteristics of these gliomas in comparison to those of IDH1 R132H mutant gliomas.

MATERIAL AND METHODS

We retrospectively analyzed the characteristics of a multicentric series of 161 gliomas with non-canonical IDH mutations and compared them to those of consecutive series of 109 IDH1 R132H mutant gliomas. Medical, radiological and pathological were reviewed.

RESULTS

Median age at diagnosis was 35 years in gliomas with a non-canonical IDH1 mutation, 42 years in those with an IDH2 mutation and 44 years in those with an IDH1R132H mutation. A familial history of cancer was more frequent in gliomas with a non-canonical IDH mutation than in those with an IDH1 R132H mutation (22,3% vs 5,5%, p<0.05). In both IDH1 R132H-mutant and non-canonical IDH-mutant gliomas the most frequent location was the frontal lobe. Yet, compared to IDH1R132H-mutant gliomas those with a non-canonical IDH mutation had more frequently an infratentorial location (5,5% vs 0% p<0,05) and were more frequently multicentric (4,9%, versus 0.9%, p<0.05). Compared to IDH1R132H-mutant gliomas, gliomas with a non-canonical IDH1 mutation were more frequently astrocytomas (65.7% vs 45%, p<0.05) while those with an IDH2 mutation were more frequently oligodendrogliomas (82% vs 55%, p<0.05). The median overall survival in IDH1 R132H-mutant and non-canonical IDH-mutant gliomas was similar (122 versus 120 months).

CONCLUSION

Gliomas with non-canonical IDH mutations are associated with distinct clinical, radiological and histological characteristics. Their prognosis, however, is similar to that of gliomas with canonical IDH mutations.

Bevacizumab and irinotecan for recurrent oligodendroglial tumors

2054

Background: Treatment with a regimen of bevacizumab/irinotecan has been shown to be effective in recurrent grade 3 and 4 gliomas, but the effect of this regimen against recurrent oligodendroglial tumors has not been specifically studied. Methods: The bevacizumab/irinotecan regimen was retrospectively evaluated in a consecutive series of 25 patients with recurrent oligodendroglial tumors. All patients had failed previous treatment with radiation therapy and at least one line of temozolomide chemotherapy. Bevacizumab (10 mg/kg) and irinotecan (125 or 340 mg/m2 according to the antiepileptic regimen) were delivered every 14 days. Response was measured clinically and on monthly MRI. Results: The objective response rate was 72% (20% complete response, 52% partial response). After a median follow-up (from the first cycle) of 310 days (95% CI, 47–499), the median progression-free survival was 174 days (95% CI, 116–342), and the median overall survival was 328 days (95%CI, 217-not reached). The 6-month progression-free survival was 42 % (95 % CI, 26% to 67%). Among the 20 patients who progressed at the time of the analysis, the radiological pattern of progression was atypical in seven patients with an isolated multifocal or diffuse spread of the FLAIR signal, or an isolated meningeal spread or FLAIR abnormalities preceding contrast-enhancement recurrence. Among the 10 patients who are still alive, two are still on follow-up since 6 months with a complete response after, respectively, 10 and 12 months of treatment. Among the 17 patients in whom the status of the main molecular alterations of gliomas could be evaluated (search for deletions of chromosomes 1p, 19q, 9p, 10q, and amplification of EGFR, MDM2, CDK4), no relation could be found between the response rate and the type of genetic change (including 1p-19q co-deletion). The profile of tolerance was fair, with treatment discontinuation in 20% of patients. Intratumoral hemorrhages occurred in six patients (24%), but the treatment had to be discontinued because of symptomatic bleeding in only one patient (4%). Conclusions: This regimen is effective in recurrent oligodendrogliomas, and the overall tolerance is acceptable.

[Table: see text]

Relations between psychotherapy and survival, coping strategies and quality of life (QOL) in patients with malignant gliomas: A randomized study

9110

Background: Cognitive and behavioral psychotherapies are able to modify reactions against stress. Whether psychotherapies can improve survival, coping strategies and QOL in situations such as cancer announcement is not known. Methods: Between September 2001 and October 2003, a single center two arms study was conducted. Voluntary patients with newly diagnosed malignant gliomas were prospectively and exhaustively randomized to have psychotherapy or not. Anti-cancer therapy was unchanged. Psychotherapy was performed monthly. Coping strategies and QOL using EORTC QLQ-C30 Questionnaire were evaluated every 6 months for one year. Results: 96 patients were randomized and 81 patients (50 men, 81%) completed the study. Mean age was 50 years (range: 22–67) and 79% had a performance status = 1, 70% had glioblastomas, 51% had at least partial surgical resection of the tumor, 95% received radiotherapy and 83% had at least 1 cycle of chemotherapy. After a median follow-up of 43 months, 68 deaths (84%) were noted and median survival time was 14.1 months. Despite a trend toward improved survival, psychotherapy was not a prognosis factor of survival (p = 0.19). Coping scores at 0, 6 and 12 months were similar in the two arms and no improvements between base line scores and later scores were noted. General QOL scores at 0, 6 and 12 months were similar in the two arms. More data will be presented at the meeting, notably in good responders to psychotherapy. Conclusions: In a large non selected population of patients with newly diagnosed malignant gliomas, psychotherapy does not improve coping score or QOL and doesn't significantly change survival. Further studies are required to determine which patients can benefit of psychotherapy.

No significant financial relationships to disclose.

[Cellular sources of reactive oxygen and nitrogen species. Roles in signal transcription pathways]

The history of studies regarding reactive oxygen and nitrogen species (ROS/RNS) is approximatively of 50 years. ROS were shown initially for their deleterious effects on marcormolecules such as DNA and proteins, leading to deterioration of cellular functions as an oxidative stress. On the other hand, recent studies have demonstrated that ROS/RNS act as oxidative signalling in cells, resulting in various gene expressions. This brief review focuses on the main cellular origins of ERO/ERN, such as mitochondrial respiratory chain, NAD(P)H oxidase and NO synthases, and describe the modulation by the reactive species of two major signal transduction pathways, NF-KB and AP-1 pathways.

Cricotracheal resection in children weighing less than 10 kg

OBJECTIVE

To review cricotracheal resection (CTR) in children weighing less than 10 kg.

DESIGN AND SETTING

Retrospective study of 17 patients (mean follow-up, 23 months) from 3 ear, nose, and throat pediatric centers.

PATIENTS

Seventeen children (10 boys and 7 girls; mean age, 14.6 months; and mean weight, 7.6 kg) undergoing CTR from June 1995 to March 2003.

MAIN OUTCOME MEASURES

Decannulation rates and endoscopies.

RESULTS

The cause was congenital subglottic stenosis in 2 children (12%) and acquired subglottic stenosis in 15 (88%). All but 1 had grade 3 or 4 stenosis. The mean hospitalization duration was 34 days. Single-stage CTR was performed in 11 children (65%), with peroperative decannulation in 7. Extubation of these patients occurred between days 3 and 9. Decannulation of the other 6 patients was performed after a median of 15 days. Sixteen (94%) of the 17 children were decannulated. Four patients required additional carbon dioxide laser treatment for subsequent glottic or subglottic edema or granulomas, but no reintubation was necessary. One child could not be decannulated because of bronchopulmonary disease, and subglottic stenosis recurred. Long-term tracheotomy was avoided in all other patients. Another child died of cardiac disease. All other patients remained free of significant subglottic stenosis at follow-up.

CONCLUSIONS

Cricotracheal resection in small children weighing less than 10 kg was a safe and effective procedure for severe subglottic stenosis. To our knowledge, this is the first reported attempt of CTR in this weight category, providing results comparable to those published in older children.

[Diabetes mellitus, oxidative stress and advanced glycation endproducts]

Chronic hyperglycemia in diabetes mellitus is an oxidative stress created by an imbalance of prooxidants over antioxidant defenses. The pathogenesis would involve several mechanisms including glucose autoxidation, protein glycation, the polyol pathway, and overproduction of superoxide radicals in mitochondria and via NAD(P)H oxidase. Glycemic equilibrium plays a very important role in the prooxidant/antioxidant balance. Macromolecules such as found in the extracellular matrix, lipoproteins, and deoxyribonucleic acid also constitute targets for free radicals in diabetes mellitus. This oxidative tress is involved in the pathophysiology of diabetes complications. The chronic hyperglycemic status also favors glycation reactions (irreversible glucose binding on protein amino groups), thereby leading to advanced glycation endproducts. Via their recognition by cell receptors, advanced glycation endproducts also participate in the development of oxidative stress and the inflammatory status. Involvement of oxidative stress and advanced glycation endproducts in diabetes complications is the basis of the development of adjunct therapies with antioxidant and/or anti)advanced glycation endproducts molecules.

[Clinical and embryological approaches to nasal dermoid sinus cysts]

Nasal dermoid sinus cyst (NDSC) is an uncommon congenital lesion presenting as a large panel of midline craniofacial anomalies. Thirty children with nasal midline masses and/or sinus ostia were surgically treated in the pediatric ENT and cervicofacial surgery department of Trousseau's children's hospital (Paris-France) between 1995 and 2002. All our patients underwent radiological evaluation including CT scan (including axial and coronal planes) and/or MRI (in all three planes) in search of intracranial extension. Thirteen of our patients presented with a midline cyst only, ten had nasal pit only, and seven had combined anomalies. Preoperative radiology and surgery showed an intracranial extension in 3 patients, which exhibited contact of the cyst with the dura. Recurrence being expected if any dermal tissues were left in place, "one-time-excision management" was the rule. CT and MR imaging features were reviewed. The external rhinoplasty procedure resulted in a wide surgical approach, low recurrence and good esthetic results. The embryological and anatomical origins of NDSCs are reviewed. Development of NDSC during embryological development implicates two necessary and sufficient conditions: competence of the ectodermal and mesectodermal cells to form dermoid tissue with epithelial-mesenchymal interactions, and a topographical site of ectodermal inclusion, which fits well with the various clinical presentations of NDSCs. We propose to distinguish NDSCs of anterior topography, located at the anterior skull base level from the basal NDSCs, located at the middle skull base level. We reviewed the various localizations of NDSCs, revisiting a forgotten embryological theory, which unify the various clinical localizations of anterior NDSCs.

Comparison of the effects of O2*-/HO* free radical- and copper ions-oxidized LDL or lipoprotein(a) on the endothelial cell releases of tissue plasminogen activator and plasminogen activator inhibitor-1

We investigated the effects of low density-lipoproteins (LDL) and lipoprotein(a) [Lp(a)] oxidized by O2*-/HO* free radicals generated by gamma radiolysis of water, on the release of tissue Plasminogen Activator (tPA) and of its main inhibitor Plaminogen Activator Inhibitor-1 (PAI-1) by human umbilical vein endothelial cells (HUVEC). These effects were compared to those of lipoproteins issued from the same preparations but oxidized by the classical copper ions procedure. The results showed that O2*-/HO* free radical oxidized LDL and Lp(a) led to a dramatic decrease of PAI-1 release but did not affect tPA release, whereas copper oxidation of lipoproteins resulted in an increase in PAI-1 release and a decrease in tPA release. Chemical analysis revealed that O2*-/HO* free radical oxidized lipoproteins exhibited very much lower levels of phosphatidylcholine hydroperoxides, lysophosphatidylcholine and oxysterols (7-ketocholesterol, 7beta-hydroxycholesterol, 5,6beta-epoxycholesterol) than copper oxidized LDL. Thus, the discordant effects of O2*-/HO* oxidized and copper oxidized LDL and Lp(a) on the endothelial releases of PAI-1 and tPA appeared to be due to qualitatively and/or quantitatively different formation of oxidized components by the two oxidation processes.

Inter-laboratory evaluation of the COBAS INTEGRA 400 analytical system

COBAS INTEGRA 400 is a random-access analytical system consolidating assays for clinical chemistry analytes, electrolytes, serum proteins, drugs of abuse and therapeutic drugs. Analytical performance and practicability of the instrument were evaluated in seven laboratories over a 2-year period in parallel with system development. Good within-run and total imprecision for all assays was observed with a few exceptions for specimen pools with low concentration or activity. The coefficients of variation for total imprecision were well below 3.0% for clinical chemistry analytes and electrolytes, and below 5.0% for serum proteins and therapeutic drugs. Method comparisons demonstrated a good agreement with the various systems used for comparison, with slopes varying typically from 0.94 to 1.05, and Spearman correlation coefficient generally > 0.975. Accuracy was verified by recovery of controls and certified reference materials within 90 to 110% of target values. Assay ranges were linear within +/- 5%. No carry-over on reagent or sample pipetting systems was observed. Manufacturer-specified interference limits and onboard stabilities of reagents were confirmed. A time study for calculating direct personnel times and total processing time was carried out in three laboratories under different conditions including consolidated, STAT and dedicated use. On a scenario-independent basis, the total working time was shorter on the COBAS INTEGRA 400 than on routine systems in all three laboratories. Personnel time, in particular, was significantly reduced when compared to routine instruments. In general, system practicability was judged very positively in all laboratories. Owing to its versatility, the instrument is best placed as a consolidated workstation in small- to medium-sized laboratories or as an instrument for special determinations such as serum proteins, drugs, urinalysis or emergency analyses in large laboratories.

Antioxidant effect of ethanol toward in vitro peroxidation of human low-density lipoproteins initiated by oxygen free radicals

This study was designed to evaluate the effect of ethanol on the peroxidation of human low-density lipoprotein (LDL) initiated by oxygen free radicals (O(2)(.-) and (.)OH in the absence of ethanol; O(2)(.-) and ethanol-derived peroxyl radicals, RO(2)(.), in the presence of ethanol) generated by gamma radiolysis. Initial radiolytic yields as determined by several markers of lipid peroxidation [i.e. decrease in endogenous antioxidants alpha-tocopherol and beta-carotene, formation of conjugated dienes and of thiobarbituric acid-reactive substances (TBARS)] were determined in 3 g liter(-1) LDLs (expressed as total LDL concentration) in the absence of ethanol or its presence at six different concentrations (0.42-17 x 10(-2) mol liter(-1)). Ethanol acted as an antioxidant by decreasing the rate of consumption of LDL endogenous antioxidants and the yields of formation of lipid peroxidation products, and by delaying the onset of the propagation phase for conjugated dienes and TBARS. With regard to the different markers studied, except for alpha-tocopherol and beta-carotene consumption, the effect of ethanol did not appear to be dependent on its concentration. Indeed, (.)OH were scavenged by ethanol at the lowest ethanol concentration (0.42 x 10(-2) mol liter(-1)), leading to RO(2)(.). These RO(2)(.) resulted in lower radiation-induced yields related to endogenous antioxidant consumption or to formation of lipid peroxidation products (for example, approximately 10% of RO(2)(.) oxidized LDLs from TBARS). Thus, under our in vitro conditions, ethanol behaved as an antioxidant when added to the LDL solutions. This should be taken into account in the reported antioxidant activity of wine. This is also of interest when lipophilic compounds have to be added as ethanolic solutions to LDLs to evaluate in vitro their antioxidant activity toward LDL peroxidation.

Blood oxidative stress and lipoprotein oxidizability in haemodialysis patients: effect of the use of a vitamin E-coated dialysis membrane

BACKGROUND

Oxidative stress has been shown in haemodialysis patients in relation with an increased production of free radicals due to membrane-induced complement and leukocyte activation. In order to minimize membrane bioincompatibility and thereby oxidative stress, more compatible filters have been perfected. Among them, a high-flux vitamin E-coated membrane (CL-EE) has been proposed recently. In vivo, little data is available on the consequences of the use of vitamin E-coated membranes. In the present study, the effects of a 3-month use of CL-EE dialysis membranes compared to conventional membranes have been evaluated in 12 haemodialysis patients on the blood oxidative stress status before and after the dialysis session.

METHODS

We determined the lipid peroxidation status (plasma thiobarbituric acid-reactive substances) and antioxidant defence (erythrocyte Cu,Zn-superoxide dismutase and plasma and erythrocyte glutathione peroxidase activities, plasma vitamin E, beta-carotene, vitamin A and total antioxidant status). Also, we simultaneously determined the antioxidant content and the copper oxidizability of isolated low density- and high density-lipoproteins (LDLs and HDLs).

RESULTS

The main consequence observed under these conditions was a marked enrichment of plasma with vitamin E, which was also significantly and selectively noted in HDLs (no changes in LDL vitamin E content), perhaps related to a specific storage capacity for vitamin E in HDLs of haemodialysis patients. The beta-carotene content of plasma, LDLs and HDLs was also higher after use of vitamin E-coated membranes than after use of high-flux biocompatible membranes. HDL copper oxidizability was reduced (as shown by an increased lag time) before dialysis after use of CL-EE membranes compared to conventional membranes, whereas LDL oxidizability remained unchanged.

CONCLUSION

A 3-month use of vitamin E-coated membranes resulted in a significant increase in plasma and HDL vitamin E content, associated with a lower oxidizability of HDLs, which could be beneficial for haemodialysis patients.

Blood oxidative stress in amyotrophic lateral sclerosis

It has been suggested that amyotrophic lateral sclerosis (ALS), a neurodegenerative disorder resulting in motor neuron death, is associated with oxidative damage induced by free radicals. Our study aimed to get an assessment of the blood oxidative stress status in a population of 167 ALS patients (aged 59+/-13 years), treated or not with riluzole, compared with 62 age-matched healthy control subjects (aged 60+/-11 years) simultaneously included in the study. We determined the level of plasma lipid peroxidation (thiobarbituric acid-reactive substances, TBARS); the status of the major lipophilic plasma antioxidant defenses (vitamin E, vitamin A and beta-carotene); the activities of erythrocyte Cu,Zn-superoxide dismutase (Cu,Zn-SOD) and of plasma and erythrocyte glutathione peroxidase (GSH-Px). Plasma selenium was also determined as a trace element essential to the activity of the GSH-Px. In comparison with controls, we observed in ALS patients (mean+/-S.D.) significantly higher TBARS values (ALS=1.34+/-0.28 micromol/l; controls=1.11+/-0. 20 micromol/l) and a significant enhancement of the erythrocyte SOD activity (ALS=710+/-114 U/g Hb; controls=667+/-93 U/g Hb). No differences were observed for selenium level, GSH-Px activity, plasma vitamin E, beta-carotene and vitamin A concentrations. These data confirm the presence of an oxidative stress in blood of ALS patients. The elevated plasma TBARS, without any deficiency in plasma lipophilic antioxidants such as vitamin E, vitamin A and beta-carotene, suggest an enhancement in the production of free radicals. No correlation was found in our study between the level of any of the blood oxidative stress markers and the disease duration. Comparison between patients treated or not with riluzole did not display any modification of the plasma TBARS concentration, but we observed a slight decrease of erythrocyte SOD activity in treated patients (treated=705+/-113 U/g Hb; not treated=725+/-118 U/g Hb), suggesting a possible activity of riluzole on the oxygenated free radical production.

Cold preservation injury in rat liver: effect of liposomally-entrapped adenosine triphosphate

BACKGROUND/AIMS

Energy charge and capacity for adenosine triphosphate (ATP) synthesis have been demonstrated to play a major role in the maintenance of organ function after liver preservation for transplantation. The aim of this study was to evaluate whether a supply of liposomally-entrapped ATP during preservation could improve the energy state and metabolism of cold-stored rat liver.

METHODS

In the first set of experiments, the uptake of ATP-containing liposomes and their effects on hepatic viability were determined in isolated perfused unstored rat liver. In the second set of experiments, rat livers were preserved for 18 h at 4 degrees C in UW solution in the presence of these liposomes, and effects on energy state, cell volume and metabolism were evaluated. In each part, data were compared with adequate control, unloaded liposome-treated, and free ATP-treated groups (n=6 in each group).

RESULTS

In non-stored livers, ATP-containing liposomes were taken up by the liver; they did not alter hepatic viability and induced a decrease in energy substrate consumption (glucose and amino acids), and an improvement in intrahepatic ATP content (+23% vs. Control). Addition of liposomally-entrapped ATP during cold storage produced a significant attenuation of the decrease in hepatic ATP content (Lip ATP 2: 524+/-45 vs. Control 2: 364+/-106 nmol/g; p<0.05), and induced, during reperfusion, a decrease in proteolysis associated with an increase in cell volume compared with the other groups (Lip ATP 2: 633+/-63 vs. Control 2: 532+/-38, Unloaded Lip 2: 483+/-55 and Free ATP 2: 500+/-29 microl/g; p<0.01).

CONCLUSIONS

These data indicate that liposomally-entrapped ATP represents an effective means to improve liver graft energy state and function. The decrease in protein degradation may be related to the modification of cell volume.

Consequences of the diabetic status on the oxidant/antioxidant balance

It has been shown that elevated extra- and intra-cellular glucose concentrations result in an oxidative stress, which is defined as an imbalance between prooxidants and antioxidants. Several mechanisms seem to be involved in the genesis of this oxidative stress, which has been reported both in experimental diabetes in animals and in type 1 and type 2 diabetic patients: glucose autoxidation, protein glycation and formation of advanced glycation endproducts, and the polyol pathway. Reciprocally, oxidative stress is involved in the origin of type 1 diabetes, especially via the apoptosis of pancreatic beta-cells, as well as insulin resistance in type 2 diabetes. Glucose control plays an important role in the prooxidant/antioxidant balance. Macromolecules such as molecules of extracellular matrix, lipoproteins and deoxyribonucleic acid are also damaged by free radicals in diabetes mellitus. A supplementation with antioxidants has been proposed as a complementary treatment, and some antidiabetic agents may by themselves have antioxidant properties independently of their role on glucose control. The aim of this paper was to review the consequences of the diabetic status on the oxidant/antioxidant balance.

Protection of endogenous vitamin E and beta-carotene by aminoguanidine upon oxidation of human low-density lipoproteins by *OH/O(2)*-

This study was designed to evaluate the antioxidant effect of aminoguanidine toward human low-density lipoproteins (LDLs) initiated by oxygenated free radicals (*OH/O(2)*-) generated by gamma radiolysis. Initial radiolytic yields related to the markers of lipid peroxidation [i.e. decrease in endogenous alpha-tocopherol and beta-carotene, formation of thiobarbituric acid-reactive substances (TBARS) and conjugated dienes] were determined in 3 g liter(-1) LDLs (expressed as total LDL concentration) in the absence and presence of 10 different concentrations of aminoguanidine (from 0.04 to 5 mmol liter(-1)). Fluorescence and relative electrophoretic mobility of oxidized LDLs were also studied as markers that indirectly reflect the attack of the protein moiety of LDLs (namely apolipoprotein B). Our data clearly showed the inhibitory effect of aminoguanidine on lipid peroxidation induced in LDLs by *OH/O(2)*- in a concentration-dependent manner. This effect probably resulted from a scavenging activity of aminoguanidine toward *OH. In contrast, aminoguanidine did not appear to react significantly with O(2)*-, which resulted in a poor residual lipid peroxidation. Our data led us to determine an optimum [aminoguanidine]/[LDL] ratio ranging from 250 to 500 to obtain the best in vitro protection of LDLs under our experimental conditions. It is also of great interest that aminoguanidine was able to protect endogenous alpha-tocopherol and beta-carotene of LDLs upon *OH/O(2)*(-)-induced oxidation.

Oxidizability of atherogenic low-density lipoprotein subspecies in severe familial hypercholesterolemia: impact of long-term low-density lipoprotein apheresis

BACKGROUND

Oxidative modification of low-density lipoprotein (LDL) plays a key role in the pathophysiology of atherosclerosis. LDL-apheresis, which involves direct removal of plasma LDL from circulating blood, is an efficient treatment of homozygous familial hypercholesterolemia (FH).

METHODS

We evaluated impact of long-term LDL apheresis treatment on the atherogenicity of the major LDL subclasses (light, LDL1, and LDL2, density [d] 1.018-1.030 g/mL; intermediate, LDL3, d 1.030-1.040 g/mL, and dense LDL, LDL4 and LDL5, d 1.040-1.065 g/mL) separated by density gradient ultracentrifugation in severe FH patients. Therefore, we compared the oxidative resistance as well as the chemical and physical properties of each LDL subpopulation in the FH group with those in the corresponding LDL subfractions from normocholesterolemic control subjects.

RESULTS

Both intermediate and dense LDL subfractions were significantly more resistant to copper-mediated oxidation in FH patients treated regularly by LDL-apheresis than their counterpart controls. The lag phases for LDL3, LDL4, and LDL5: 63.9+/-11.6, 55.8+/-1.2, and 47.2+/-6.5 min. in FH patients were significantly longer than those of the corresponding subfractions in normocholesterolemic controls (P <.01 for LDL3 and LDL5, P<.005 for LDL4). This protective effect was reflected in the delayed formation of biologically active lipid oxidation products such as oxysterols, lipid hydroperoxides, dienes, and dienals in the intermediate and dense LDL subfractions of FH patients. These findings may result from lower "seed" contents of lipid hydroperoxide (LOOH) detected as dienes in plasma LDL from apheresis-treated FH patients; indeed, baseline LOOH/diene contents in all 5 LDL subclasses from FH patients were significantly lower than those of the corresponding subclasses in normolipidemic subjects (P<.0005). On the other hand, the enhanced oxidative resistance of both intermediate (LDL3) and dense (LDL4 and LDL5) LDL subpopulations in FH patients could not be accounted for by any consistent modification in chemical composition or in lipophilic antioxidant content, although minor differences were observed between patients and controls in unsaturated fatty acid profile. In contrast, sphingomyelin content was enriched in FH LDL subclasses, potentially resulting in reduced penetration of the hydrophilic surface layer of LDL by oxygen radicals.

CONCLUSION

We conclude that low concentrations of preformed lipid hydroperoxides and dienes, together with surface sphingomyelin enrichment, can account for the enhanced oxidative resistance of intermediate (LDL3) and atherogenic dense LDL (LDL4, LDL5) induced by long-term LDL apheresis in severe FH patients.

[Endoscopic surgical treatment of Zenker hypopharyngeal diverticuli. Apropos of 59 cases]

We report our experience with 59 cases of Zenker's diverticulum, all treated endoscopically from 1979 to 1998. The ages ranged from 59 to 98 years. There were contraindications for conventional surgery or deep general anesthesia for all the patients. The surgical technique of endoscopic treatment was performed under general anesthesia, using a specially designed endoscope for exposure. Scissors, and after 1990 CO2 LASER, were used to divide the posterior cricopharyngeal muscle fibers. There was no major complication. Our results are comparable with literature, 92% success, even though a small diverticulum may paradoxically remain. Besides, from our experience, it may be necessary to perform two sessions for diverticulum larger than 3 cm. This safe and efficient treatment can be recommended for patients of all ages with a contraindication for conventional surgery.

High density lipoproteins (HDL) and the oxidative hypothesis of atherosclerosis

The oxidative hypothesis of atherosclerosis classically implies a central role for low density lipoprotein (LDL) oxidation. However, new antiatherogenic properties have been recognized for high density lipoproteins (HDL), apart from their ability to reverse cholesterol transport. Indeed, native HDL could protect LDL from oxidation, thereby minimizing the deleterious consequences of this process. Several mechanisms have been suggested to explain this protective role. Two HDL-associated enzymes, paraoxonase and PAF-acetylhydrolase, detoxify oxidized phospholipids produced by lipid peroxidation. In addition, HDL could reduce hydroperoxides to their corresponding hydroxides. It has also been suggested that HDL could inhibit oxidized LDL-induced transduction signals. However, in vivo HDL oxidation in the subendothelial space would favor the atherosclerotic process. Indeed, atherogenic properties of these oxidized HDL partly result from some loss of their cholesterol effluxing capacity and from an inactivation of the lecithin-cholesterol acyltransferase, which is a HDL-associated enzyme involved in reverse cholesterol transport. Finally, oxidized HDL could induce cholesterol accumulation in macrophages. Further in-depth investigation is needed to assess these antagonistic effects and their consequences for the atherosclerotic process.