Dosimetric and biologic intercomparison between electron and proton FLASH beams

BACKGROUND AND PURPOSE

The FLASH effect has been validated in different preclinical experiments with electrons (eFLASH) and protons (pFLASH) operating at an average dose rate above 40 Gy/s. However, no systematic intercomparison of the FLASH effect produced by eFLASHvs. pFLASH has yet been performed and constitutes the aim of the present study.

MATERIALS AND METHODS

The electron eRT6/Oriatron/CHUV/5.5 MeV and proton Gantry1/PSI/170 MeV were used to deliver conventional (0.1 Gy/s eCONV and pCONV) and FLASH (≥110 Gy/s eFLASH and pFLASH) dose rates. Protons were delivered in transmission. Dosimetric and biologic intercomparisons were performed using previously validated dosimetric approaches and experimental murine models.

RESULTS

The difference between the average absorbed dose measured at Gantry 1 with PSI reference dosimeters and with CHUV/IRA dosimeters was -1.9 % (0.1 Gy/s) and + 2.5 % (110 Gy/s). The neurocognitive capacity of eFLASH and pFLASH irradiated mice was indistinguishable from the control, while both eCONV and pCONV irradiated cohorts showed cognitive decrements. Complete tumor response was obtained after an ablative dose of 20 Gy delivered with the two beams at CONV and FLASH dose rates. Tumor rejection upon rechallenge indicates that anti-tumor immunity was activated independently of the beam-type and the dose-rate.

CONCLUSION

Despite major differences in the temporal microstructure of proton and electron beams, this study shows that dosimetric standards can be established. Normal brain protection and tumor control were produced by the two beams. More specifically, normal brain protection was achieved when a single dose of 10 Gy was delivered in 90 ms or less, suggesting that the most important physical parameter driving the FLASH sparing effect might be the mean dose rate. In addition, a systemic anti-tumor immunological memory response was observed in mice exposed to high ablative dose of electron and proton delivered at CONV and FLASH dose rate.

The effectiveness of lucid dreaming therapy in patients with nightmares: A systematic review

OBJECTIVES

Nightmares can be defined as "an unpleasant dream with anxiety and oppression". They represent a symptom possibly leading to serious psychiatric and physical consequences. It occurs to 2% to 8% of the general population. Lucid dreaming therapy (LDT) is an interesting upcoming psychotherapy for the treatment of nightmares. The aim of this study was to evaluate the efficacy of LDT in the treatment of nightmares in adults and children.

METHODS

We performed a systematic review of the literature, based on the Cochrane organisation's methodology. We explored the PubMed, Cochrane library, PsycINFO via Ovid and Embase databases and clinical trial registries (CTR), namely clinicaltrials.gov, EU clinical trials and the WHO clinical trials registry platform.

RESULTS

Four randomized controlled trials (RCT), 2 case series and 5 case reports were included. Most of the included studies found LDT effective in reducing nightmare frequency among adults with chronic and recurring nightmares. We did not identify any reports in children.

CONCLUSIONS

Despite a limited internal validity for the included studies, these first results are encouraging. Nonetheless, larger and more rigorous studies would allow to better assess the utility of LDT for nightmares.

Dosimetric and biologic intercomparison between electron and proton FLASH beams

Background and purpose

The FLASH effect has been validated in different preclinical experiments with electrons (eFLASH) and protons (pFLASH) operating at a mean dose rate above 40 Gy/s. However, no systematic intercomparison of the FLASH effect produced by e vs. pFLASH has yet been performed and constitutes the aim of the present study.

Materials and methods

The electron eRT6/Oriatron/CHUV/5.5 MeV and proton Gantry1/PSI/170 MeV were used to deliver conventional (0.1 Gy/s eCONV and pCONV) and FLASH (≥100 Gy/s eFLASH and pFLASH) irradiation. Protons were delivered in transmission. Dosimetric and biologic intercomparisons were performed with previously validated models.

Results

Doses measured at Gantry1 were in agreement (± 2.5%) with reference dosimeters calibrated at CHUV/IRA. The neurocognitive capacity of e and pFLASH irradiated mice was indistinguishable from the control while both e and pCONV irradiated cohorts showed cognitive decrements. Complete tumor response was obtained with the two beams and was similar between e and pFLASH vs. e and pCONV. Tumor rejection was similar indicating that T-cell memory response is beam-type and dose-rate independent.

Conclusion

Despite major differences in the temporal microstructure, this study shows that dosimetric standards can be established. The sparing of brain function and tumor control produced by the two beams were similar, suggesting that the most important physical parameter driving the FLASH effect is the overall time of exposure which should be in the range of hundreds of milliseconds for WBI in mice. In addition, we observed that immunological memory response is similar between electron and proton beams and is independent off the dose rate.

SCN5A mutations and the role of genetic background in the pathophysiology of Brugada syndrome

Background

Mutations in SCN5A are identified in approximately 20% to 30% of probands affected by Brugada syndrome (BrS). However, in familial studies, the relationship between SCN5A mutations and BrS remains poorly understood. The aim of this study was to investigate the association of SCN5A mutations and BrS in a group of large genotyped families.

Methods

Families were included if at least 3 family members were carriers of the SCN5A mutation, which was identified in the proband. Families were recruited from 12 tertiary centers in France between 1995 and 2020. Type 1 ST elevation was defined by ≥2 mm J-point elevation with coved ST segment and negative T wave.

Results

Forty-nine large families composed of 600 members including 304 mutation carriers (51%) were studied. The signature type I ECG was present in 160 mutation carriers (BrS-ECG+; 53%). In 42 families, we found 33 individuals affected by BrS but with a negative genotype (mutation-negative BrS-ECG+). Among them, 5 patients have an ECG suggestive of BrS but without the complete signature type I ECG. Among these 33 mutation-negative BrS-ECG+ individuals, 3 (9%), belonging to 3 different families, had a spontaneous type I ECG, whereas 28 had a type I ECG only after the administration of sodium channel blockers. Three of these 33 individuals (9%) had also experienced syncope. Mutation carriers had, on average, longer PR (190±36 ms vs 154±29 ms, p<0.0001) and QRS (107±19 vs 92±29 ms, p<0.0001) intervals than noncarriers, demonstrating that these mutations exerted functional effects.

Conclusions

Our results suggest that SCN5A mutations are not directly causal to the occurrence of a BrS-ECG+ and that genetic background may play a powerful role in the pathophysiology of BrS. These findings are consistent with the notion that the pathophysiology of BrS includes various elements beyond mutant sodium channels.

Funding Acknowledgement

Type of funding sources: None.

Distinct nitrogen isotopic compositions of healthy and cancerous tissue in mice brain and head&neck micro-biopsies

BACKGROUND

Cancerous cells can recycle metabolic ammonium for their growth. As this ammonium has a low nitrogen isotope ratio (15N/14N), its recycling may cause cancer tissue to have lower 15N/14N than surrounding healthy tissue. We investigated whether, within a given tissue type in individual mice, tumoral and healthy tissues could be distinguished based on their 15N/14N.

METHODS

Micro-biopsies of murine tumors and adjacent tissues were analyzed for 15N/14N using novel high-sensitivity methods. Isotopic analysis was pursued in Nude and C57BL/6 mice models with mature orthotopic brain and head&neck tumors generated by implantation of H454 and MEERL95 murine cells, respectively.

RESULTS

In the 7 mice analyzed, the brain tumors had distinctly lower 15N/14N than healthy neural tissue. In the 5 mice with head&neck tumors, the difference was smaller and more variable. This was at least partly due to infiltration of healthy head&neck tissue by tumor cells. However, it may also indicate that the 15N/14N difference between tumoral and healthy tissue depends on the nitrogen metabolism of the healthy organ in question.

CONCLUSIONS

The findings, coupled with the high sensitivity of the 15N/14N measurement method used here, suggest a new approach for micro-biopsy-based diagnosis of malignancy as well as an avenue for investigation of cancer metabolism.

Adherence to geriatric assessment-based recommendations in older patients with cancer: a multicenter prospective cohort study in Belgium

Background

In the general older population, geriatric assessment (GA)-guided treatment plans can improve overall survival, quality of life and functional status (FS). In GA-related research in geriatric oncology, studies mainly focused on geriatric screening and GA but not on geriatric recommendations, interventions and follow-up. The aim of this study was to investigate the adherence to geriatric recommendations and subsequent actions undertaken in older patients with cancer.

Patient and methods

A prospective Belgian multicenter (N = 22) cohort study included patients ≥70 years with a malignant tumor upon oncologic treatment decision. Patients with an abnormal result on the geriatric screening (G8 ≤14/17) underwent GA. Geriatric recommendations were formulated based on GA results. At follow-up the adherence to geriatric recommendations was documented including a description of actions undertaken.

Results

From November 2012 till February 2015, G8 screening was carried out in 8451 patients, of which 5838 patients had an abnormal result. Geriatric recommendations data were available for 5631 patients. Geriatric recommendations were made for 4459 patients. Geriatric interventions data were available for 4167 patients. A total of 12 384 geriatric recommendations were made. At least one different geriatric recommendation was implemented in 2874 patients. A dietician, social worker and geriatrician intervened most frequently for problems detected on the nutritional, social and functional domain. A total of 7569 actions were undertaken for a total of 5725 geriatric interventions, most frequently nutritional support and supplements, extended home care and psychological support.

Conclusions

This large-scale Belgian study focuses on the adherence to geriatric recommendations and subsequent actions undertaken and contributes to the optimal management of older patients with cancer. We identified the domains for which geriatric recommendations are most frequently made and adhered to, and which referrals to other health care workers and facilities are frequently applied in the multidisciplinary approach of older patients with cancer.

Determining clinically important differences in health-related quality of life in older patients with cancer undergoing chemotherapy or surgery

PURPOSE

Using the EORTC Global Health Status (GHS) scale, we aimed to determine minimal clinically important differences (MCID) in health-related quality of life (HRQOL) changes for older cancer patients with a geriatric risk profile, as defined by the geriatric 8 (G8) health screening tool, undergoing treatment. Simultaneously, we assessed baseline patient characteristics prognostic for HRQOL changes.

METHODS

Our analysis included 1424 (G8 ≤ 14) older patients with cancer scheduled to receive chemotherapy (n = 683) or surgery (n = 741). Anchor-based methods, linking the GHS score to clinical indicators, were used to determine MCID between baseline and follow-up at 3 months. A threshold of 0.2 standard deviation (SD) was used to exclude MCID estimates too small for interpretation. Logistic regressions analysed baseline patient characteristics prognostic for HRQOL changes.

RESULTS

The 15-item Geriatric Depression Scale (GDS15), Visual Analogue Scale (VAS) for Fatigue and ECOG Performance Status (PS) were selected as clinical anchors. In the surgery group, MCID estimates for improvement and deterioration were ECOG PS (5*, 11*), GDS15 (5*, 2) and VAS Fatigue (3, 9*). In the chemotherapy group, MCID estimates for improvement and deterioration were ECOG PS (8*, 7*), GDS15 (5, 4) and VAS Fatigue (5, 5*). Estimates with * were > 0.2 SD threshold. Patients experiencing pain or malnutrition (surgery group) or fatigue (chemotherapy group) at baseline showed a significantly stable or improved HRQOL (p < 0.05) after their treatment.

CONCLUSION

The reported MCID for improvement and deterioration depended on the anchor used and treatment received. The estimates can be used to evaluate significant changes in HRQOL and to determine sample sizes in clinical trials.

Transcriptomic approach for assessment of the impact on microalga and macrophyte of in-situ exposure in river sites contaminated by chlor-alkali plant effluents

Water quality degradation is a worldwide problem, but risk evaluation of chronic pollution in-situ is still a challenge. The present study aimed to evaluate the potential of transcriptomic analyses in representative aquatic primary producers to assess the impact of environmental pollution in-situ: the microalga Chlamydomonas reinhardtii and the macrophyte Elodea nuttallii were exposed 2 h in the Babeni Reservoir of the Olt River impacted by chlor-alkali plant effluent release resulting in increased concentrations of Hg and NaCl in receiving water. The response at the transcriptomic level was strong, resulting in up to 5485, and 8700 dysregulated genes (DG) for the microalga and for the macrophyte exposed in the most contaminated site, respectively. Transcriptomic response was congruent with the concentrations of Hg and NaCl in the water of the impacted reservoir. Genes involved in development, energy metabolism, lipid metabolism, nutrition, and RedOx homeostasis were dysregulated during in-situ exposure of both organisms. In addition, genes involved in the cell motility of C. reinhardtii and development of the cell wall of E. nuttallii were affected. DG were in line with adverse outcome pathways and transcriptomic studies reported after exposure to high concentrations of Hg and NaCl under controlled conditions in the laboratory. Transcriptomic response provided a sensitive measurement of the exposure as well as hints on the tolerance mechanisms of environmental pollution, and is thus promising as an early-warning tool to assess water quality degradation.

A Belgian Survey on Geriatric Assessment in Oncology Focusing on Large-Scale Implementation and Related Barriers and Facilitators

OBJECTIVES

The aim of this study is to describe a large-scale, Belgian implementation project about geriatric assessment (=GA) in daily oncology practice and to identify barriers and facilitators for implementing GA in this setting. Design / setting / participants: The principal investigator of every participating hospital (n=22) was invited to complete a newly developed questionnaire with closed- and open-ended questions. The closed-ended questions surveyed how GA was implemented. The open-ended questions identified barriers and facilitators for the implementation of GA in daily oncology practice. Descriptive statistics and conventional content analysis were performed as appropriate.

RESULTS

Qualifying criteria (e.g. disease status and cancer type) for GA varied substantially between hospitals. Thirteen hospitals (59.1%) succeeded to screen more than half of eligible patients. Most hospitals reported that GA data and follow-up data had been collected in almost all screened patients. Implementing geriatric recommendations and formulating new geriatric recommendations at the time of follow-up are important opportunities for improvement. The majority of identified barriers were organizational, with high workload, lack of time or financial/staffing problems as most cited. The most cited facilitators were all related to collaboration.

CONCLUSION

Interventions to improve the implementation of GA in older patients with cancer need to address a wide range of factors, with organization and collaboration as key elements. All stakeholders, seeking to improve the implementation of GA in older patients with cancer, should consider and address the identified barriers and facilitators.

Sonothrombolysis: the contribution of stable and inertial cavitation to clot lysis

Microbubble-mediated sonothrombolysis (STL) is a remarkable approach to vascular occlusion therapy. However, STL remains a complex process with multiple interactions between clot, ultrasound (US), microbubbles (MB) and thrombolytic drug. The aim of this study was to evaluate the ability of combining US and MB to degrade fibrin and, more specifically, to assess the roles of both stable (SC) and inertial (IC) cavitation. Human blood clots containing radiolabeled fibrin were exposed to different combinations of recombinant tissue plasminogen activator (rtPA), US (1 MHz) and phospholipid MB. Three acoustic pressures were tested: 200, 350 and 1,300 kPa (peak-negative pressure). Clot lysis was assessed by diameter loss and release of radioactive fibrin degradation products. The combination rtPA + US + MB clearly revealed that IC (1,300 kPa) was able to enhance fibrin degradation significantly (66.3 ± 1.8%) compared with rtPA alone (51.7 ± 2.0%, p < 0.001). However, SC failed to enhance fibrin degradation at an acoustic pressure of 200 kPa. At 350 kPa, a synergistic effect between rtPA and US + MB was observed with an absolute increase of 6% compared to rtPA alone (p < 0.001). Conversely, without rtPA, the combination of US + MB was unable to degrade the fibrin network (0.3 ± 0.1%, p > 0.05 vs. control), but induced a distinct loss of red blood cells throughout the entire thickness of the clot, implying that MB were able to penetrate and cavitate inside the clot.

RelA and RelB cross-talk and function in Epstein-Barr virus transformed B cells

In this study, we determined the respective roles of RelA and RelB NF-κB subunits in Epstein-Barr virus (EBV)-transformed B cells. Using different EBV-immortalized B-cell models, we showed that only RelA activation increased both survival and cell growth. RelB activity was induced secondarily to RelA activation and repressed RelA DNA binding by trapping the p50 subunit. Reciprocally, RelA activation repressed RelB activity by increasing expression of its inhibitor p100. To search for such reciprocal inhibition at the transcriptional level, we studied gene expression profiles of our RelA and RelB regulatable cellular models. Ten RelA-induced genes and one RelB-regulated gene, ARNTL2, were repressed by RelB and RelA, respectively. Apart from this gene, RelB signature was included in that of RelA Functional groups of RelA-regulated genes were for control of energy metabolism, genetic instability, protection against apoptosis, cell cycle and immune response. Additional functions coregulated by RelA and/or RelB were autophagy and plasma cell differentiation. Altogether, these results demonstrate a cross-inhibition between RelA and RelB and suggest that, in fine, RelB was subordinated to RelA. In the view of future drug development, RelA appeared to be pivotal in both classical and alternative activation pathways, at least in EBV-transformed B cells.

[Interest of coronary flow reserve of the LAD during dobutamine stress echocardiography]

AIM OF THE STUDY

To assess the value of the coronary flow reserve (CFR) in the left anterior descending artery (LAD) during dobutamine stress echocardiography in the diagnosis of significant LAD stenosis (more than 70%).

METHOD

Retrospective study of 81 patients with a positive stress echocardiography who underwent a coronarography.

RESULTS

Measurement of coronary flow reserve was able in half echocardiographic exams. Medium Pic diastolic velocity was 0.33 m/s (SD 0.20), medium maximal diastolic velocity during stress was 0.62 m/s (SD 0.20), medium CFR was 2.25 (SD 0.65). In 50 patients LAD was not seen; in five of them LAD was occluded. The predictive positive value (PPV) of a low coronary flow reserve to detect LAD stenosis is 66.7% and the negative predictive value (NPV) is 65.4%. An abnormal anterior contraction during stress echo with a low reserve has a PPV of 75% for the diagnosis of significant IVA stenosis and a normal contraction during stress with normal coronary flow reserve means a NPV of 65%. We did not show a significant correlation between low coronary flow and abnormal contraction during stress echocardiography (kappa 0.51).

CONCLUSION

Coronary flow reserve of LAD during stress echo is feasible but does not really improve exam performance to detect significant IVA stenosis. This measurement remains to be clear in coronary patients management.

Simultaneous analysis of serotonin transporter, tryptophan hydroxylase 1 and 2 gene expression in the ventral prefrontal cortex of suicide victims

Serotonergic signaling abnormalities have been implicated in suicide. Tryptophan hydroxylase (TPH), the rate limiting enzyme of serotonin biosynthesis and the serotonin transporter (SLC6A4), involved in the reuptake of serotonin from the synaptic gap, play major role in serotonergic signaling. In this study, we aimed to compare the levels of expression of these serotonin-related genes between suicide completers and controls and to identify genetic loci involved in their regulation. SLC6A4, TPH1, and TPH2 mRNA levels were measured in the ventral prefrontal cortex (VPFC) of 39 suicide completers and 40 matched controls. To identify the molecular basis of gene expression variation, we performed association studies between cis-acting polymorphisms and SLC6A4, TPH1, and TPH2 transcript levels. Finally, association analyses were carried out between suicide and TPH2 cis-single nucleotide polymorphisms (SNPs) in cohorts of 154 suicide completers and 289 control subjects. Whereas SLC6A4 and TPH1 mRNA expression levels did not differ between suicides and controls, TPH2 levels were found significantly increased (P = 0.003) in suicide completers. We observed that SNP rs10748185 located in the promoter region of TPH2 significantly affect levels of TPH2 mRNA expression. However, we did not find positive association between this eQTL (rs10748185) and suicide. Here, we report the simultaneous analysis of the expression of three serotonin-related genes in the VPFC of suicide victims and controls. This study showed that TPH2 expression levels were increased in the VPFC of suicide victims. Although, we identified a genetic variant that explains variance in TPH2 expression, we did not find evidence associating this cis-regulatory SNP with suicidal behavior.

Elevated Tribbles homolog 2-specific antibody levels in narcolepsy patients

Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness and attacks of muscle atonia triggered by strong emotions (cataplexy). Narcolepsy is caused by hypocretin (orexin) deficiency, paralleled by a dramatic loss in hypothalamic hypocretin-producing neurons. It is believed that narcolepsy is an autoimmune disorder, although definitive proof of this, such as the presence of autoantibodies, is still lacking. We engineered a transgenic mouse model to identify peptides enriched within hypocretin-producing neurons that could serve as potential autoimmune targets. Initial analysis indicated that the transcript encoding Tribbles homolog 2 (Trib2), previously identified as an autoantigen in autoimmune uveitis, was enriched in hypocretin neurons in these mice. ELISA analysis showed that sera from narcolepsy patients with cataplexy had higher Trib2-specific antibody titers compared with either normal controls or patients with idiopathic hypersomnia, multiple sclerosis, or other inflammatory neurological disorders. Trib2-specific antibody titers were highest early after narcolepsy onset, sharply decreased within 2-3 years, and then stabilized at levels substantially higher than that of controls for up to 30 years. High Trib2-specific antibody titers correlated with the severity of cataplexy. Serum of a patient showed specific immunoreactivity with over 86% of hypocretin neurons in the mouse hypothalamus. Thus, we have identified reactive autoantibodies in human narcolepsy, providing evidence that narcolepsy is an autoimmune disorder.

Genetic and epigenetic analysis of SSAT gene dysregulation in suicidal behavior

It has recently been proposed that the SSAT gene plays a role in the predisposition to suicidal behavior. SSAT expression was found to be down-regulated in the brain of suicide completers. In addition, a single nucleotide polymorphism (SNP) rs6526342 was associated both with variation in SSAT expression and with suicidal behavior. In this study, we aimed to characterize the relationship between SSAT dysregulation and suicide behavior. To this end, we measured SSAT expression levels in the ventral prefrontal cortex (VPFC) of suicide completers (n = 20) and controls (n = 20) and found them to be significantly down-regulated in suicide victims (P = 0.007). To identify the basis of the regulation of SSAT expression, we performed an association analysis of 309 SNPs with SSAT transcript levels in 53 lymphoblastoid cell lines from the CEPH collection. We then examined the methylation status of the SSAT promoter region in males and females suicide completers and control subjects whose SSAT brain expression had been measured. We found no evidence to support a role for SNPs in controlling the level of SSAT expression. SSAT promoter methylation levels were not different between suicide completers and controls and did not correlate with SSAT expression levels. In addition, we found no indication of a genetic association between suicidal behavior and SNPs located within the SSAT gene. Our study provides new results which show that dysregulation of SSAT expression does play a role in suicide behavior. However, our data do not support any association between rs6526342 and variation in SSAT expression or suicidal behavior.

L-asparaginase-based treatment of 15 western patients with extranodal NK/T-cell lymphoma and leukemia and a review of the literature

BACKGROUND

Extranodal natural killer (NK)/T-cell lymphoma, nasal type, and aggressive NK-cell leukemia are highly aggressive diseases with a poor outcome.

PATIENTS AND METHODS

We report a multicentric French retrospective study of 15 patients with relapsed, refractory, or disseminated disease, treated with L-asparaginase-containing regimens in seven French centers. Thirteen patients were in relapse and/or refractory and 10 patients were at stage IV.

RESULTS

All but two of the patients had an objective response to L-asparaginase-based treatment. Seven patients reached complete remission and only two relapsed.

CONCLUSION

These data, although retrospective, confirm the excellent activity of L-asparaginase-containing regimens in refractory extranodal NK/T-cell lymphoma and aggressive NK-cell leukemia. Therefore, L-asparaginase-based regimen should be considered as a salvage treatment, especially for patients with disseminated disease. First-line L-asparaginase combination therapy for extranodal NK/T-cell lymphoma and aggressive NK-cell leukemia should be tested in prospective trials.

[Multinodular goitre with widespread vasculitis of thyroid arteries revealing temporal giant cell arteritis]

We describe a 62-year-old woman with slowly growing usual nodular goitre in whom diffuse giant cell arteritis (GCA) of the thyroid arteries was found upon thyroidectomy, revealing otherwise unsuspected biopsy-proven temporal arteritis. To our knowledge, this association had been previously reported in only three instances. In each case, GCA of the thyroid arteries appeared clinically silent, did not produce significant glandular dysfunction, and was uncovered thanks to a planned thyroidectomy for nodular goitre. These observations highlight that thyroid artery involvement by GCA, even widespread, as in our patient, may be overlooked clinically and may produce little or no thyroid dysfunction.

Sleep EEG changes after middle cerebral artery infarcts in mice: different effects of striatal and cortical lesions

STUDY OBJECTIVES

Hemispheric stroke in humans is associated with sleep-wake disturbances and sleep electroencephalogram (EEG) changes. The correlation between these changes and stroke extent remains unclear. In the absence of experimental data, we assessed sleep EEG changes after focal cerebral ischemia of different extensions in mice.

DESIGN

Following electrode implantation and baseline sleep-wake EEG recordings, mice were submitted to sham surgery (control group), 30 minutes of intraluminal middle cerebral artery (MCA) occlusion (striatal stroke), or distal MCA electrocoagulation (cortical stroke). One and 12 days after stroke, sleep-wake EEG recordings were repeated. The EEG recorded from the healthy hemisphere was analyzed visually and automatically (fast Fourier analysis) according to established criteria.

MEASUREMENTS AND RESULTS

Striatal stroke induced an increase in non-rapid eye movement (NREM) sleep and a reduction of rapid eye movement sleep. These changes were detectable both during the light and the dark phase at day 1 and persisted until day 12 after stroke. Cortical stroke induced a less-marked increase in NREM sleep, which was present only at day 1 and during the dark phase. In cortical stroke, the increase in NREM sleep was associated in the wake EEG power spectra, with an increase in the theta and a reduction in the beta activity.

CONCLUSION

Cortical and striatal stroke lead to different sleep-wake EEG changes in mice, which probably reflect variable effects on sleep-promoting and wakefulness-maintaining neuronal networks.

The loss of circadian PAR bZip transcription factors results in epilepsy

DBP (albumin D-site-binding protein), HLF (hepatic leukemia factor), and TEF (thyrotroph embryonic factor) are the three members of the PAR bZip (proline and acidic amino acid-rich basic leucine zipper) transcription factor family. All three of these transcriptional regulatory proteins accumulate with robust circadian rhythms in tissues with high amplitudes of clock gene expression, such as the suprachiasmatic nucleus (SCN) and the liver. However, they are expressed at nearly invariable levels in most brain regions, in which clock gene expression only cycles with low amplitude. Here we show that mice deficient for all three PAR bZip proteins are highly susceptible to generalized spontaneous and audiogenic epilepsies that frequently are lethal. Transcriptome profiling revealed pyridoxal kinase (Pdxk) as a target gene of PAR bZip proteins in both liver and brain. Pyridoxal kinase converts vitamin B6 derivatives into pyridoxal phosphate (PLP), the coenzyme of many enzymes involved in amino acid and neurotransmitter metabolism. PAR bZip-deficient mice show decreased brain levels of PLP, serotonin, and dopamine, and such changes have previously been reported to cause epilepsies in other systems. Hence, the expression of some clock-controlled genes, such as Pdxk, may have to remain within narrow limits in the brain. This could explain why the circadian oscillator has evolved to generate only low-amplitude cycles in most brain regions.

Bone formation in hydroxyapatite tricalcium phosphate ceramic implants used in the treatment of the postenucleation socket syndrome

PURPOSE

To determine the histopathologic changes in coralline hydroxyapatite tricalcium phosphate (HA-TCP) blocks used in the treatment of the postenucleation socket syndrome (PESS).

METHODS

Twenty-four patients were treated with HA-TCP blocks placed directly into the orbital fat to correct the PESS. Eight of these patients required partial removal of the material for various reasons between 32 and 371 days after the initial operation. The orbital implants were decalcified and processed for light and electron microscopic examination.

RESULTS

Light microscopy demonstrated fibrovascular ingrowth into the pores of the implant in all cases. Osteogenesis was observed in three cases in the periphery of the implant. Ossification occurred in the implants after a mean implantation duration of 276 days versus 67 days in cases without ossification.

CONCLUSION

Implants of HA-TCP, a new material used in ophthalmology, demonstrate the presence of fibrovascular ingrowth, reflecting the excellent biointegration of this material.

Deficiency in short-chain fatty acid beta-oxidation affects theta oscillations during sleep

In rodents, the electroencephalogram (EEG) during paradoxical sleep and exploratory behavior is characterized by theta oscillations. Here we show that a deficiency in short-chain acyl-coenzyme A dehydrogenase (encoded by Acads) in mice causes a marked slowing in theta frequency during paradoxical sleep only. We found Acads expression in brain regions involved in theta generation, notably the hippocampus. Microarray analysis of gene expression in mice with mutations in Acads indicates overexpression of Glo1 (encoding glyoxylase 1), a gene involved in the detoxification of metabolic by-products. Administration of acetyl-L-carnitine (ALCAR) to mutant mice significantly recovers slow theta and Glo1 overexpression. Thus, an underappreciated metabolic pathway involving fatty acid beta-oxidation also regulates theta oscillations during sleep.

Characteristics of secondary acute lymphoblastic leukemia with L3 morphology in adult patients

Secondary acute lymphoblastic leukemia (sALL) is an uncommon condition and sALL with L3 morphology is still less frequent. Here, we compare the characteristics of available cases of L3 sALL (16 patients, including 12 previously published cases and 4 personal cases) to those of de novo L3 ALL and of non L3 sALL. Two patients with L3 sALL obtained a CR after aggressive treatment of their leukemia. Compared with 24 patients from the literature with de novo L3 ALL, L3 sALL patients were characterized by an older age (median 46 vs. 29.5 years, p = 0.0003) and by a poor prognosis (complete responses: 2/16 vs. 19/24, p = 0.0001, median survival: 0.46 month vs. undetermined, p < 0.0001). In comparison with 19 patients from the literature with non L3 sALL, L3 sALL patients were characterized by a high Male/Female ratio (14/2 vs. 8/11, p = 0.01), a frequent history of Hodgkin's disease (12/16 vs. 7/19, p = 0.04) and, again, by a poor prognosis (complete responses: 2/16 vs. 13/18, p = 0.0001, median survival 0.46 vs. 13 months, p = 0.001). In conclusion, though based on a small group of heterogeneously treated patients, some characteristics of L3 sALL, seem to emerge, compared both with de novo L3 ALL and with non L3 sALL, the most prominent being its extremely poor prognosis.

Real-time PCR for quantification of human herpesvirus 6 DNA from lymph nodes and saliva

A real-time quantitative PCR assay has been developed to measure human herpesvirus 6 (HHV-6) DNA in biological specimens. The assay sensitivity was 10 copies of DNA per well, with a linear dynamic range of 10 to 10(7) copies of HHV-6 DNA. Intra- and interassay variations were, respectively, 0.88 and 0.8% for samples containing 10(2) DNA copies, 0.99 and 0.96% for samples containing 10(4) copies, and 0.76 and 0.9% for samples containing 10(6) copies. Among 34 saliva samples from healthy subjects, 26 were found to contain HHV-6 DNA (76.5%; median, 23,870 copies/ml), and following a single freeze-thaw cycle, 25 of the same samples were found to be positive for HHV-6 DNA, although at a statistically significantly lower concentration (median, 3,497 copies/ml). The assay enabled detection of HHV-6 DNA in lymph node biopsies from patients with Hodgkin's disease (HD) (13 of 37 patients [35.1%]), B-cell neoplasms (8 of 36 patients [22.2%]), and T- or NK-cell neoplasms (3 of 13 patients [23.1%]), with concentrations ranging from 100 to 864,640 HHV-6 copies per microg of DNA (HHV-6B being found in every case except two). All HD patients infected with HHV-6 presented clinically with the nodular sclerosis subtype of HD. The real-time quantitative PCR assay developed here was simple to perform and was sensitive over a wide range of HHV-6 concentrations. It therefore appears to be of potential value in clinical investigation or diagnosis of HHV-6 infection.

p53 gene mutations are associated with poor survival in low and low-intermediate risk diffuse large B-cell lymphomas

BACKGROUND

p53 alterations have been associated with a poor prognosis in aggressive B-cell lymphoma. We investigated the clinical relevance of p53 status in diffuse large B-cell lymphoma (DLBCL), focusing on patients who belong to lower risk groups of the international prognostic index and were uniformly treated. We aimed to determine whether this biological marker could identify among such patients those with a pejorative outcome who could benefit from a distinct therapeutic approach.

PATIENTS AND METHODS

We studied 69 patients presenting with no, one (low-risk, n = 40) or two (low-intermediate risk, n = 29) risk factors treated with an anthracyclin-containing induction regimen. p53 exons 5-8 mutations were screened for using denaturing gradient gel electrophoresis and confirmed by direct sequencing. Immunohistochemical detection of p53 protein and of its downstream target p21 were also evaluated in 60 of 69 cases.

RESULTS

p53 mutations were detected in 16 of 69 (23%) lymphoma samples. The presence of a p53 gene mutation affected survival (P = 0.01), with a 6-year survival rate estimated to be 44% in mutated patients, compared with 79% in non-mutated ones. Using a stepwise Cox model, p53 mutation constituted the only parameter affecting survival (relative risk = 2.7, P = 0.03). A p53+/p21- immunohistochemical pattern (n = 15), suggestive of a disrupted p53 function, strongly correlated with p53 gene status and was associated with a lower 6-year survival rate when compared with a p53(-) or p53+/p21+ phenotype (47% versus 74%, P = 0.05).

CONCLUSIONS

p53 alterations constitute a pejorative biological indicator able to discriminate among clinically defined lower risk patients with DLBCL.