Evaluation of azacitidine and entinostat as sensitization agents to cytotoxic chemotherapy in preclinical models of non-small cell lung cancer.

Recent clinical data in lung cancer suggests that epigenetically targeted therapy may selectively enhance chemotherapeutic sensitivity. There have been few if any studies rigorously evaluating this hypothesized priming effect. Here we describe a series of investigations testing whether epigenetic priming with azacitidine and entinostat increases sensitivity of NSCLC to cytotoxic agents. We noted no differences in chemosensitivity following treatment with epigenetic therapy in in vitro assays of viability and colony growth. Using cell line and patient derived xenograft (PDX) models, we also observed no change in responsiveness to cisplatin in vivo. In select models, we noted differential responses to irinotecan treatment in vivo. In vitro epigenetic therapy prior to tumor implantation abrogated response of H460 xenografts to irinotecan. Conversely, in vitro epigenetic therapy appeared to sensitize A549 xenografts (tumor growth inhibition 51%, vs. 22% in mock-pretreated control). In vivo epigenetic therapy enhanced the response of adenocarcinoma PDX to irinotecan. Taken together, these data do not support broadly applicable epigenetic priming in NSCLC. Priming effects may be context-specific, dependent on both tumor and host factors. Further preclinical study is necessary to determine whether, and in which contexts, priming with epigenetic therapy has potential to enhance chemotherapeutic efficacy in NSCLC patients.

A comprehensive model of care for rehabilitation of children with acquired brain injuries.

BACKGROUND: Acquired brain injury (ABI) is a leading cause of death and lifelong acquired disability in children and remains a significant public health issue. Deficits may only become fully apparent when developmental demands increase and once cognitive processes are expected to be fully developed. It is therefore necessary to provide organized long-term follow-up for children post ABI. Despite these recommendations, it has been shown that only a small proportion of children received specialized rehabilitation and adequate follow-up after ABI. AIMS: The aims are: (i) to describe a comprehensive model of care devoted to children with acquired brain injuries; and (ii) to provide descriptive data analysing the characteristics of children followed up, the type/amount of services provided and general outcomes. PROGRAMME DESCRIPTION: The programme features an in- and outpatient rehabilitation facility, where multidisciplinary rehabilitation and specialized schooling are provided. The ultimate goal of the programme is to promote each child's successful reintegration in school and in the community. Adequate preparation of discharge is essential, long-term follow-up is organized, and an outreach programme has been developed to deal with the complex delayed psychosocial issues. RESULTS: Overall outcome, as measured by the Glasgow Outcome Scale, improved dramatically between admission (3.3; SD = 0.45) and discharge (2.15; SD = 0.74). Most of the children were discharged home with an adequate personalized plan for ongoing rehabilitation and school adaptations. Analysis of the outreach programme underlines the more challenging issues arising in late adolescence-early adulthood. CONCLUSION: Given the specificities of childhood ABI, long-term specific care must be organized and co-ordinated, regardless of injury severity.

Impact of apoE deficiency on oxidative insults and antioxidant levels in the brain.

Apolipoprotein E (apoE) is a lipid transport molecule, which has been linked to the pathogenesis of Alzheimer's disease. Recently we have demonstrated that the oxidative insults in hippocampus from AD patients were dependent on the apoE genotype. Interestingly, apoE protein concentration in hippocampus follows a genotype-dependent gradient with the lowest level occurring in varepsilon4 allele carrier. We raised the possibility that, in the hippocampus, the apoE level affects the oxidant/antioxidant balance. Here, we have examined in the apoE-deficient mouse the oxidant/antioxidant status in hippocampus and in frontal cortex from APOE-KO and wild-type mice at 3 and 13 months. We provided evidence that, in the hippocampus, the absence of apoE has a clear impact on the oxidant/antioxidant status. Endogenous level of thiobarbituric acid-reactive substances (TBARS) was found to be markedly elevated whereas level of alpha-tocopherol was decreased in APOE-deficient mice at 3 and 13 months. Superoxide dismutase activities were also lower in APOE-deficient mice at 13 months. Taken together, these data indicate that the steady state level of apoE may influence, to a certain extent, the balance between oxidants and antioxidants in hippocampus.

[Pseudohypoparathyroidism or hypoparathyroidism? A misleading clinical presentation]. / Pseudohypoparathyroïdie ou hypoparathyroïdie?

We report the case of a 27-year old woman who presented hypocalcemia and hyperphosphoremia during her first pregnancy. Her phenotype was in favor of Albright's hereditary osteodystrophy: short stature, obesity, round face, brachymetacarpy and mental retardation. However, the diagnosis of pseudohypopara thyroidism type Ia was ruled out due to low PTH level (10 pg/ml). The patient's 22q11 microdeletion was suspected and identified because of the association of severe neonatal hypocalcemia, abnormal face and renal malformation in her children. Deletion 22q11 leads to various syndromes, including Di George syndrome, also referred to as CATCH 22 syndrome (Cardiac defect (C), Abnormal face (A), Thymic hypoplasia (T), Cleft palate (C) and Hypocalcemia (H)). Retrospectively, the patient presented with symptoms suggestive of CATCH 22: abnormal face, hypernasal voice suggestive of velopharyngeal insufficiency, mental retardation, recurrent otitis in childhood. It is also noteworthy that there was an idiopathic thrombocytopenic purpura. In conclusion, while the phenotype was suggestive of Albright's hereditary osteodystrophy, the constatation of a low PTH level would cast doubt on this diagnosis. Furthermore, the 22q11 microdeletion should be searched by FISH (Fluorescence In Situ Hybridization) in all patients with hypopara thyroidism of unknown origin, even in the absence of cardiac malformations. Finally, it seems that patients with CATCH 22 would be predisposed to auto-immune disease as a result of thymic dysfunction.

The Ginkgo biloba extract (EGb 761) protects hippocampal neurons against cell death induced by beta-amyloid.

Substantial evidence suggests that the accumulation of beta-amyloid (Abeta)-derived peptides, and to a lesser extent free radicals, may contribute to the aetiology and/or progression of Alzheimer's disease (AD). Ginkgo biloba extract (EGb 761) is a well-defined plant extract containing two major groups of constituents, i.e. flavonoids and terpenoids. It is viewed as a polyvalent agent with a possible therapeutic use in the treatment of neurodegenerative diseases of multifactorial origin, e.g. AD. We have investigated here the potential effectiveness of EGb 761 against toxicity induced by (Abeta)-derived peptides (Abeta25-35, Abeta1-40 and Abeta1-42) on hippocampal primary cultured cells, this area being severely affected in AD. A co-treatment with EGb 761 concentration-dependently (10-100 microg/mL) protected hippocampal neurons against toxicity induced by Abeta fragments, with a maximal and complete protection at the highest concentration tested. Similar, albeit less potent protective effects were seen with the flavonoid fraction of the extract (CP 205), while the terpenes were ineffective. Most interestingly, EGb 761 (100 microg/mL) was even able to protect (up to 8 h) hippocampal cells from a pre-exposure to Abeta25-35 and Abeta1-40. EGb 761 was also able to both protect and rescue hippocampal cells from toxicity induced by H2O2 (50-150 microM), a major peroxide possibly involved in mediating Abeta toxicity. Moreover, EGb 761 (10-100 microg/mL), and to a lesser extent CP 205 (10-50 microg/mL), completely blocked Abeta-induced events, e.g. reactive oxygen species accumulation and apoptosis. These results suggest that the neuroprotective effects of EGb 761 are partly associated with its antioxidant properties and highlight its possible effectiveness in neurodegenerative diseases, e.g. AD via the inhibition of Abeta-induced toxicity and cell death.

Oxidative damage and protection by antioxidants in the frontal cortex of Alzheimer's disease is related to the apolipoprotein E genotype.

A great number of epidemiological studies have demonstrated that the frequency of the epsilon4 allele of the apolipoprotein E gene (APOE) is markedly higher in sporadic and in familial late onset Alzheimer disease (AD). In the frontal cortex of AD patients, oxidative damage is elevated. We address the hypothesis that the APOE genotype and reactive oxygen-mediated damage are linked in the frontal cortex of AD patients. We have related the APOE genotype to the levels of lipid oxidation (LPO) and to the antioxidant status, in frontal cortex tissues from age-matched control and AD cases with different APOE genotypes. LPO levels were significantly elevated in tissues from Alzheimer's cases which are homozygous for the epsilon4 allele of APOE, compared to AD epsilon3/epsilon3 cases and controls. Activities of enzymatic antioxidants, such as catalase and glutathione peroxidase (GSH-PX), were also higher in AD cases with at least one epsilon4 allele of APOE, while superoxide dismutase (SOD) activity was unchanged. In the frontal cortex, the concentration of apoE protein was not different between controls and AD cases, and was genotype independent. The Ginkgo biloba extract (EGb 761), the neurosteroid dehydroepiandrosterone (DHEA) and human recombinant apoE3 (hapoE3rec) were able to protect control, AD epsilon3/epsilon3 and epsilon3/epsilon4 cases against hydrogen peroxide/iron-induced LPO, while hapoE4rec was completely ineffective. Moreover, EGb 761 and DHEA had no effect in homozygous epsilon4 cases. These results demonstrate that oxidative stress-induced injury and protection by antioxidants in the frontal cortex of AD cases are related to the APOE genotype.

Dehydroepiandrosterone (DHEA) protects hippocampal cells from oxidative stress-induced damage.

It has been postulated that decreases in plasma levels of dehydroepiandrosterone (DHEA) may contribute to the development of some age-related disorders. Along with neuroprotective and memory enhancing effects, DHEA has been shown to display antioxidant properties. Moreover, oxidative stress is known to cause lipid peroxidation and degenerative changes in the hippocampus, an area involved in memory processes and especially afflicted in Alzheimer's disease (AD). Accordingly, we investigated the antioxidant effects of DHEA in models of oxidative stress using rat primary hippocampal cells and human hippocampal tissue from AD patients and age-matched controls. A pre-treatment of rat primary mixed hippocampal cell cultures with DHEA (10-100 microM) protected against the toxicity induced by H2O2 and sodium nitroprusside. Moreover, DHEA (10-100 microM) was also able to prevent H2O2/FeSO4-stimulated lipid oxidation in both control and AD hippocampal tissues. Taken together, these data suggest that DHEA may be useful in treating age-related central nervous system diseases based on its protective effects in the hippocampus.

Cauda equina syndrome with pagetic vertebral fusion. Clinical recovery under calcium-vitamin D supplementation plus clodronate after apparent failure of pamidronate and acquired resistance to etidronate.

A patient with an osteolytic L2-L3 pagetic block and pagetic lesions of L1 and the sacrum seen only as increased radionuclide activity became resistant to etidronate after the fifth course (5 mg/kg/d six months per year) and developed severe cauda equina syndrome (reduction in walking distance to 30 m and sphincter dysfunction) due primarily to vertebral hypertrophy. Five months after a ten-day course of intravenous pamidronate (22.5 mg/d), the clinical symptoms were unchanged, although the alkaline phosphatase level was down 50%. Oral clodronate (1,600 mg/day for six months per year) in combination with calcium and vitamin D supplementation dramatically improved the walking distance and sphincter disorders. Resolution of the neurological manifestations was complete after the second clodronate course. At last follow-up nine months after the fourth clodronate course, there was no evidence of a relapse and the alkaline phosphatase level was normal. The time course of events in this patient does not allow to affirm that pamidronate was ineffective and suggests that calcium and vitamin D supplementation improved mineralization of the pagetic block and enhanced the effect of bisphosphonate therapy.

L-Deprenyl and MDL72974 do not improve the recovery of dopaminergic cells following systemic administration of MPTP in mouse.

L-Deprenyl, a monoamine oxidase B (MAO-B) inhibitor, administered prior to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) protects dopaminergic neurons against degeneration in several animal species including mice. L-Deprenyl inhibits MPP+ formation, the mediator of MPTP toxicity. In addition, L-deprenyl, administered 72 h following MPTP, improves the recovery of tyrosine hydroxylase (TH) immunopositive neurons in the substantia nigra (SN) of mice. This observation lead to the proposal that L-deprenyl exerts a 'neurorescue' effect. However, clinical trials failed to demonstrate that L-deprenyl can effectively 'rescues' degenerating dopaminergic neurons in early untreated Parkinson's disease (PD) patients. These observations prompted us to reevaluate the long-term impact of L-deprenyl on MPTP-induced dopaminergic cell loss in mice. In addition, we made use of another MAO-B inhibitor, MDL72974, to assess MAO-B participation in this paradigm. Our results suggest that L-deprenyl does not improve the recovery of TH immunopositive neurons in MPTP-treated mice. An apparent reduction in TH+ neurons is observed in the SN of MDL72974 and L-deprenyl/MPTP-treated mice at 30 days post-treatment. The possible implication of these findings in relation to the used of MAO-B inhibitors in PD is discussed.

Mexiletine antagonizes effects of sotalol on QT interval duration and its proarrhythmic effects in a canine model of torsade de pointes.

OBJECTIVES: The arrhythmogenic and electrophysiologic properties of sotalol, a class III antiarrhythmic drug, administered alone and in combination with mexiletine, a class I antiarrhythmic drug, were compared in conscious dogs predisposed to torsade de pointes arrhythmias. BACKGROUND: The utility of sotalol is limited by proarrhythmia related to excessive delays in repolarization. The addition of mexiletine may limit the risk of torsade de pointes because it reduced in vitro the sotalol-induced increase in action potential duration. METHODS: Two studies were performed in eight hypokalemic dogs (plasma potassium level < or = 3.2 mmol/liter) with chronic atrioventricular block (mean ventricular cycle length, RR 1,100 ms) at 3-day intervals using a crossover protocol. Intravenous sotalol (4.5 + 1.5 mg/kg body weight per h) alone was given for 2 h, or, on another day, an intravenous mexiletine infusion (4.5 + 1.5 mg/kg per h) was begun 30 min before sotalol infusion. Spontaneous ventricular cycle length and QT interval and ventricular effective refractory period at the 1,000-ms pacing cycle length were measured at baseline and 30 min after the onset of each drug infusion. The electrocardiogram (ECG) was continuously monitored for torsade de pointes. RESULTS: Sotalol plus mexiletine and sotalol alone had a significant (p < or = 0.05) and similar effect on ventricular cycle length (+ 800 +/- 93 vs. + 690 +/- 104 ms [mean +/- SEM]) and ventricular effective refractory period (+ 20 +/- 4 vs. + 25 +/- 4 ms), but sotalol plus mexiletine had a lesser effect on QT interval (+ 20 +/- 6 vs. + 50 +/- 8 ms, p < or = 0.05). Torsade de pointes is less frequent (one of eight dogs vs. six of eight dogs, p = 0.02) with sotalol plus mexiletine than with sotalol alone. CONCLUSIONS: The coadministration of a class Ib agent can reduce the proarrhythmic potential of a class III drug in experimental animals predisposed to torsade de pointes arrhythmias and further suggests the clinical utility of such a strategy.

Evidence for a protein-like factor from "rete testis" fluid that suppresses luteinizing hormone-releasing hormone (LHRH) pulses (LHRH statin): a new hormonal activity?

Signals that modulate LH-releasing hormone (LHRH) pulse frequency are fundamental mechanisms for regulating important reproductive processes. Gonadal steroids are presently considered to account for the entire gonadal feedback mechanism that modulates LHRH secretion. However, we have previously suggested that a testicular protein(s) present in charcoal-treated rete testis fluid (ctRTF) can suppress LH pulsatility in the ram. The present experiments were aimed at determining whether the disappearance of LH pulses induced by ctRTF administration implicate a hypothalamic or a pituitary site of action. Thus, we have examined the effects of ctRTF peripheral administration on 1) the LH response to LHRH, 2) LHRH portal blood levels, and 3) LHRH content in hypothalamic tissue. Finally, the effects of ctRTF administered into the third ventricle on plasma LH levels were assessed. The present results show that a testicular protein(s) is able to suppress LHRH pulse frequency without affecting amplitude and without any effect on the LH response to LHRH (LHRH Statin). The observation that an active dose administered by the intracerebroventricular route is 0.0005 the active dose needed by the peripheral route reinforces this evidence. These data lead to the new concept that the testicular signals that govern LHRH pulse frequency may be not only steroids, but also proteins.

Combined in situ hybridization and immunocytochemistry in the assay of pharmacological effects on tyrosine hydroxylase mRNA concentration.

An assay for tyrosine hydroxylase (TH) mRNA by in situ hybridization in combination with immunocytochemistry (ICC) for TH on the same section is described. The in situ hybridization protocol was optimized for [35S]cRNA (complementary RNA, i.e. anti-sense strand) probe concentration and time of hybridization. The specificity of hybridization was measured by several critera. The advantage of measuring grain density versus grains per cell is discussed for quantitation of in situ autoradiography. Finally, the reserpine-induced increase in adrenal TH mRNA was used to validate quantitative aspects of the in situ hybridization technique by comparison with blot hybridization. In contrast to the adrenal, reserpine did not increase TH mRNA in substantia nigra (s. nigra) neurons as measured by either technique.

[Non-dominant hemisphere syndrome as a result of a right thalamic infarct: an anatomoclinical case]. / Syndrome de l'hémisphère mineur par infarctus thalamique droit: un cas anatomoclinique.

A 71 year old man had a massive left sensory deficit and hemiplegia, with left heminanopia, visual neglect and constructional apraxia. Moreover he experienced an extra-left arm and illusions of movements. 3 weeks later he suffered "thalamic" pain on left side; he died suddenly 6 weeks after the stroke. Post-mortem examination revealed: a) a right inner temporal and occipital infarction; b) a right thalamic infarction in the thalamogeniculate and paramedian territories; c) an infarction in the adjacent right internal capsule. Considering this case and pertinent literature on clinicopathological studies of right thalamic infarction, the authors suggest that a simultaneous ischaemia of thalamogeniculate and paramedian territories should be necessary to induce somatognosic and visuospatial disturbances.

[Thalamic dementia. Expansive lacunae of the thalamo-paramedian mesencephalic area. Hydrocephalus caused by stenosis of the aqueduct of Sylvius]. / Démence thalamique. Lacunes expansives du territoire thalamo-mésencéphalique paramédian. Hydrocéphalie par sténose de l'aqueduc de Sylvius.

The case reported here is that of a woman, without any significant pathological antecedent. At age 54, she developed signs of thalamic dementia and died 5 years later. The prominent symptoms were massive anterograde amnesia, apathia, apragmatism, ataxia and a frontal syndrome. She never showed aphasia, apraxia, agnosia or disorders of ocular motility. The C. T. Scan showed lacunar low densities in the mesencephalon and both thalami, mainly on the left side, as well as hydrocephalus caused by a stenosis of the aqueduct as shown by other neuroradiological procedures. The neuropathological examination showed space-occupying lacunae, bulging in the third ventricle, squeezing the aqueduct and protruding into the fourth ventricle. These lacunae were situated in the territory of the paramedian mesencephalo-thalamic arterial pedicle. They were perivascular spaces distensions, probably caused by disorder of the permeability of the arterial wall. This hypothesis is supported by the presence of severe lesions of segmental necrotizing angeitis on a paramedian mesencephalic artery. The etiology of this angeitis is unknown. As far as we know, such neuropathological lesions have never been reported previously. Therefore the pathology and etiopathogeny of cerebral lacunae should be reconsidered.