Scanning tunnelling spectroscopy study of paramagnetic superconducting β''-ET(4)[(H(3)O)Fe(C(2)O(4))(3)]·C(6)H(5)Br crystals

Scanning tunnelling spectroscopy (STS) and microscopy (STM) were performed on the paramagnetic molecular superconductor β''-ET(4)[(H(3)O)Fe(C(2)O(4))(3)]·C(6)H(5)Br. Under ambient pressure, this compound is located near the boundary separating superconducting and insulating phases of the phase diagram. In spite of a strongly reduced critical temperature T(c) (T(c) = 4.0 K at the onset, zero resistance at T(c) = 0.5 K), the low temperature STS spectra taken in the superconducting regions show strong similarities with the higher T(c) ET κ-derivatives series. We exploited different models for the density of states (DOS), with conventional and unconventional order parameters to take into account the role played by possible magnetic and non-magnetic disorder in the superconducting order parameter. The values of the superconducting order parameter obtained by the fitting procedure are close to the ones obtained on more metallic and higher T(c) organic crystals and far above the BCS values, suggesting an intrinsic role of disorder in the superconductivity of organic superconductors and a further confirmation of the non-conventional superconductivity in such compounds.

SCARB2 mutations in progressive myoclonus epilepsy (PME) without renal failure

OBJECTIVE

Mutations in SCARB2 were recently described as causing action myoclonus renal failure syndrome (AMRF). We hypothesized that mutations in SCARB2 might account for unsolved cases of progressive myoclonus epilepsy (PME) without renal impairment, especially those resembling Unverricht-Lundborg disease (ULD). Additionally, we searched for mutations in the PRICKLE1 gene, newly recognized as a cause of PME mimicking ULD.

METHODS

We reviewed cases of PME referred for diagnosis over two decades in which a molecular diagnosis had not been reached. Patients were classified according to age of onset, clinical pattern, and associated neurological signs into "ULD-like" and "not ULD-like." After exclusion of mutations in cystatin B (CSTB), DNA was examined for sequence variation in SCARB2 and PRICKLE1.

RESULTS

Of 71 cases evaluated, 41 were "ULD-like" and five had SCARB2 mutations. None of 30 "not ULD-like" cases were positive. The five patients with SCARB2 mutations had onset between 14 and 26 years of age, with no evidence of renal failure during 5.5 to 15 years of follow-up; four were followed until death. One living patient had slight proteinuria. A subset of 25 cases were sequenced for PRICKLE1 and no mutations were found.

INTERPRETATION

Mutations in SCARB2 are an important cause of hitherto unsolved cases of PME resembling ULD at onset. SCARB2 should be evaluated even in the absence of renal involvement. Onset is in teenage or young adult life. Molecular diagnosis is important for counseling the patient and family, particularly as the prognosis is worse than classical ULD.

Metabolic aspects of the extreme longevity

Starting from young to very old subjects, aging is associated with a progressive remodeling. Such an age-dependent remodeling process mainly affects anthropometrics, endocrine and thus, also metabolic factors. Interestingly, it occurs in some individuals successfully, while in others unsuccessfully. Centenarians in good health conditions are a very selected group of subjects representing an exceptional condition. Why the centenarians reach the extreme human life span is still unknown. Thus, in this article we will review the best known causes of age-related insulin resistance, outline the main metabolic differences between aged subjects and healthy centenarians, underline the clinical relevance of insulin resistance in the elderly and finally, we will try to propose a unifying hypothesis for explaining the development of insulin resistance with aging.

Permeability of human oocytes to ethylene glycol and their survival and spindle configurations after slow cooling cryopreservation

BACKGROUND

To develop novel cryopreservation methods, we estimated the permeability coefficients Lp (hydraulic conductivity) and P(EG) (cryoprotectant permeability) of mature human oocytes after exposure to ethylene glycol (EG) and tested the efficiency of a multi-step slow cooling protocol based on this cryoprotectant.

METHODS

Oocytes were perfused with 1.5 mol/l EG for 10 min. Oocyte volume at each time point was calculated and normalized to the original volume. Slow cooling was conducted by exposing oocytes to increasing EG concentrations (0.5, 1.0 and 1.5 mol/l n = 155) or 1.5 mol/l of propane-1,2-diol (PrOH) n = 102. Oocytes which survived cryopreservation n = 80 and fresh oocytes n = 73 were prepared for confocal microscopy analysis of the meiotic spindle.

RESULTS

During EG exposure, oocytes underwent an abrupt 50% volume reduction. Complete recovery of the initial volume was not observed. From the values of a best fit plot, the coefficients Lp = 0.82 +/- 0.29 microm min(-1) atm(-1) (mean +/- SD) and P(EG) 0.10 +/- 0.01 microm s(-1) were generated. Survival rates after freezing with EG were lower than with PrOH (51.6 versus 71.5%, respectively, P < 0.05). The frequencies of normal spindle configuration were lower in frozen EG and frozen PrOH oocytes compared with fresh oocytes (53.8, 50.9 and 66.7%, respectively, P < 0.05).

CONCLUSIONS

The oocyte plasmalemma possesses limited permeability to EG and EG exposure causes considerable osmotic stress. However, post-thaw rates of survival and normal meiotic spindle organization may be preserved by protocols which are designed in order to minimize osmotic stress.

Isolated Heterometallic Cr7Ni Rings Grafted on Au(111) Surface

A study of the deposition of heterometallic antiferromagnetically coupled rings onto gold surfaces is reported. Two new {Cr7Ni} rings, [NH2nPr2][Cr7NiF8(3-tpc)16] (1) (where 3-tpc=3-thiophenecarboxylate) and [nBuNH2CH2CH2SH] [Cr7NiF8(O2CtBu)16] (2) have been made and structurally characterized. They have been deposited from the liquid phase on Au(111) and the adsorbed molecules compared by means of scanning tunneling microscopy (STM) and X-ray photoemission spectroscopy (XPS). In both cases a two-dimensional distribution of individually accessible {Cr7Ni} heterometallic rings on the gold surface has been obtained, exploiting the direct grafting of sulfur-functionalized clusters. There is a competition between the chemisorption of the {Cr7Ni} clusters and a thiolic self-assembled monolayer (SAM) formed by free ligands. In 2, the presence of a single sulfur ligand should force the molecule to graft with the ring axis normal to the surface. The cluster stability in the STM images and the S-2p energy positions demonstrate, for both functionalizations, the strength of the grafting with the gold surface.

Efficacy of the combination of cisplatin with either gemcitabine and vinorelbine or gemcitabine and paclitaxel in the treatment of locally advanced or metastatic non-small-cell lung cancer: a phase III randomised trial of the Southern Italy Cooperative Oncology Group (SICOG 0101)

BACKGROUND

Triplet regimens were occasionally reported to produce a higher response rate (RR) than doublets in locally advanced or metastatic non-small-cell lung cancer (NSCLC). This trial was conducted to assess (i) whether the addition of cisplatin (CDDP) to either gemcitabine (GEM) and vinorelbine (VNR) or GEM and paclitaxel (PTX) significantly prolongs overall survival (OS) and (ii) to compare the toxicity of PTX-containing and VNR-containing combinations.

PATIENTS AND METHODS

Stage III or IV NSCLC patients were randomly assigned to (i) GEM 1000 mg/m(2) and VNR 25 mg/m(2) on days 1 and 8 (GV arm); (ii) GEM 1000 mg/m(2) and PTX 125 mg/m(2) on days 1 and 8 (GT arm); (iii) GV plus CDDP 50 mg/m(2) on days 1 and 8 (PGV arm); and (iv) GT plus CDDP 50 mg/m(2) on days 1 and 8 (PGT arm). Treatments were repeated every 3 weeks for a maximum of six cycles.

RESULTS

A total of 433 (stage III, 160; stage IV, 273) patients were randomly allocated to the study. RR was 48% [95% confidence interval (CI), 42% to 54%] for triplets and 35% (95% CI, 32% to 38%) for doublets (P = 0.004). Median progression-free survival (6.1 versus 5.5 months, P = 0.706) and median OS (10.7 versus 10.5 months, P = 0.379) were similar. CDDP significantly increased the occurrence of severe neutropenia (35% versus 13%), thrombocytopenia (14% versus 4%), anaemia (9% versus 3%), vomiting (6% versus 0.5%), and diarrhoea (6% versus 2%). Conversely, frequency of severe neutropenia (30% versus 17%) and thrombocytopenia (11% versus 6%) was significantly higher with VNR-containing regimens.

CONCLUSIONS

Adding CDDP to GV or GT significantly increased RR, but did not prolong the OS of patients. Among doublets, the GT regimen should be preferred in view of its better safety profile.

Alteration of the in vivo nicotinic receptor density in ADNFLE patients: a PET study

Nicotinic acetylcholine receptors (nAChRs) are involved in a familial form of frontal lobe epilepsy, autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). In several ADNFLE families, mutations were identified in the nAChR alpha4 or beta2 subunit, which together compose the main cerebral nAChR. Electrophysiological assessment using in vitro expression systems indicated a gain of function of the mutant receptors. However the precise mechanisms by which they contribute to the pathogenesis of a focal epilepsy remain obscure, especially since alpha4beta2 nAChRs are known to be widely distributed within the entire brain. PET study using [18F]-F-A-85380, a high affinity agonist at the alpha4beta2 nAChRs, allows the determination of the regional distribution and density of the nAChRs in healthy volunteers and in ADNFLE patients, thus offering a unique opportunity to investigate some in vivo consequences of the molecular defect. We have assessed nAChR distribution in eight non-smoking ADNFLE patients (from five families) bearing an identified mutation in nAChRs and in seven age-matched non-smoking healthy volunteers using PET and [(18)F]-F-A-85380. Parametric images of volume of distribution (Vd) were generated as the ratio of tissue to plasma radioactivities. The images showed a clear difference in the pattern of the nAChR density in the brains of the patients compared to the healthy volunteers. Vd values revealed a significant increase (between 12 and 21%, P < 0.05) in the ADNFLE patients in the mesencephalon, the pons and the cerebellum when compared to control subjects. Statistical parametric mapping (SPM) was then used to better analyse subtle regional differences. This analysis confirmed clear regional differences between patients and controls: patients had increased nAChR density in the epithalamus, ventral mesencephalon and cerebellum, but decreased nAChR density in the right dorsolateral prefrontal region. In five patients who underwent an additional [(18)F]-fluorodeoxyglucose (FDG) PET experiment, hypometabolism was observed in the neighbouring area of the right orbitofrontal cortex. The demonstration of a regional nAChR density decrease in the prefrontal cortex, despite the known distribution of these receptors throughout the cerebral cortex, is consistent with a focal epilepsy involving the frontal lobe. We also propose that the nAChR density increase in mesencephalon is involved in the pathophysiology of ADNFLE through the role of brainstem ascending cholinergic systems in arousal.

Cisplatin(P)-including triplets versus P-free doublets in the treatment of locally advanced or metastatic non-small cell lung cancer (NSCLC): SICOG 0101 randomized trial

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Background: We previously reported that triplets with P-gemcitabine (G) plus vinorelbine (V) (PGV) or paclitaxel (T) (PGT) prolonged the survival (S) of advanced NSCLC patients (pts) in comparison with P-based doublets (PG or PV). Aims of the present study were: (1) to compare (log-rank test) the S of P-based triplets vs P-free doublets, and (2) to compare (Fisher test) safety and response rate (RR) of T- and V-regimens. Methods: A 2x2 factorial design was adopted. Pts aged ≤ 70 years, with PS (ECOG) < 2, inoperable stage IIIA, IIIB, or IV NSCLC were randomly treated with: GV = G 1,000 mg/m2 + V 25 mg/m2 on day (D) 1 and 8; GT = G 1,000 mg/m2 + T 125 mg/m2 on D 1 and 8; PGV = P 50 mg/m2 on D 1 and 8 + GV; PGT = P 50 mg/m2 on D 1 and 8 + GT. In all arms, cycles were repeated Q 3 weeks. Only responder pts after 3 cycles received further chemotherapy (CT). Thoracic RT was delivered after CT to pts with intra-thoracic disease. 330 events were required to have a 90% power to demonstrate (two-sided P < 0.05) a 30% reduction of hazard of death. Results: From April 2001 to December 2005, 431 pts were recruited in the 4 arms. Characteristics in % were well balanced in P-based triplets and P-free doublets: males, 84/91; PS 0, 25/23; squamous cell carcinoma, 38/42; weight loss, 22/29; stage IV, 66/65; CNS metastases, 5/8; ≥ 2 metastatic sites, 29/30. So far, 411 pts were assessed for response: RR of triplets vs doublets was 88/204 (43%) vs 68/207 (33%) (P = 0.020), and of T-based vs V-based regimens was 40% vs 36% (P = 0.218). To date, 313 deaths were registered: median and 1-year S were 10.6 mo. and 41% for pts treated with triplets, and 10.4 mo. and 39% for pts treated with doublets (P = 0.786). Over initial 3 courses, occurrence of grade ≥ 3 toxicity (T vs V, % pts) was: neutropenia, 18% vs 30% (P < 0.004); febrile neutropenia, 4% vs 7%; platelets, 7% vs 12% (P = 0.056); anemia, 5% vs 7%; vomiting, 1% vs 2%; diarrhea, 6% vs 3%; stomatitis, 3% vs 0.5%. Grade ≥ 2 neurotoxicity occurred in 1% of both groups. Conclusions: Activity was significantly higher with P-based triplets, but they did not affect the OS. T-based regimens were equally active and less toxic than V-based regimens. Therefore, the GT regimen may represent a new standard of care for advanced NSCLC pts.

No significant financial relationships to disclose.

Biweekly oxaliplatin plus capecitabine (OXXEL) versus oxaliplatin plus folinic acid-modulated 5-fluorouracil i.v. bolus (OXAFAFU) in metastatic colorectal carcinoma (MCC): Safety interim analysis of a Southern Italy Cooperative Oncology Group (SICOG) phase III trial

3590

Background: We have previously reported that OXAFAFU regimen significantly prolonged the overall survival of MCC patients (pts) in comparison with IRIFAFU regimen (Comella, Ann Oncol 2005). Moreover, the OXXEL regimen showed promising activity in phase II study (Comella, Cancer Chemother Pharmacol 2005). Comparison of these two regimens in terms of safety and activity is the aim of the present trial. Methods: Pts with MCC were randomly treated with: oxaliplatin 85 mg/m2 iv on day (D) 1, levo-folinic acid 250 mg/m2 plus 5-fluorouracil 850 mg/m2 bolus iv on D 2 (OXAFAFU); or oxaliplatin 100 mg/m2 iv on D 1, Xeloda 1,000 mg/m2 twice daily po from D 1 (evening) to D 11 (morning). Treatment was delivered every 2 weeks up to progression, or for a maximum of 12 cycles. Results: From May 2004 to December 2005, 191 eligible pts were recruited (OXAFAFU, 96 pts; OXXEL, 95 pts). Characteristics of pts were well balanced in OXAFAFU vs OXXEL arm: primary colon, 74% vs 72%; PS 0/1–2, 57/43% vs 65/35%; previous adjuvant CT, 24% vs 20%; liver metastases, 80% vs 83%; ≥ 2 metastatic sites, 54% vs 49%. At this interim analysis, with a median number of 8 (range, 1–12) cycles delivered in both arms, 143 pts (OXAFAFU, 73; OXXEL, 70) were assessed for safety. In OXAFAFU vs OXXEL arm, occurrence of WHO grade ≥ 3 toxicity was: neutropenia, 29% vs 3%; anemia, 2% vs 7%; thrombocytopenia 3% vs 7%; diarrhea, 4% vs 13%; vomiting, 4% vs 3%; hand-foot syndrome, 1% vs 7%. Conclusions: At this interim analysis, the OXXEL regimen appeared to produce significantly less neutropenia than the OXAFAFU regimen, at a price of an acceptable non-hematologic toxicity. Accrual will continue up to reaching the final sample size of 300 pts.

No significant financial relationships to disclose.

MRI evidence of mesial temporal sclerosis in sporadic "benign" temporal lobe epilepsy

OBJECTIVE

To determine whether there is MRI-detectable mesial temporal sclerosis (MTS) in patients with sporadic benign temporal lobe epilepsy (BTLE).

METHODS

Brain MRIs were obtained from 101 consecutive, unrelated patients (51 women; mean age 37.3 +/- 17.5 years; range 10 to 83 years) with BTLE, who reported rarely or never having had seizures at the time of long-term (> 2 years) follow-up. The mean age at seizure onset was 22.3 +/- 17.4 years; the mean duration of epilepsy was 16.4 +/- 14.1 years. MRI diagnosis of MTS was based on the occurrence of hippocampal formation atrophy on T1 slices, an increased mesial temporal signal intensity alteration on fluid-attenuated inversion-recovery (FLAIR) or T2 images, or both.

RESULTS

Thirty-nine of 101 patients (38.6%) had MRI evidence of unilateral MTS (19/39 left MTS, 20/39 right MTS), which correlated with the epileptiform activity. Hyperintense FLAIR and T2 signal with or without atrophy was observed in 24 of 39 individuals. There was no difference between patients with or without MRI-detected MTS in age at onset and duration of epilepsy. Family history of epilepsy or febrile convulsions (FCs) was more frequent in patients with MRI-detected MTS (36%) as compared with patients with normal MRI (22.7%), but the difference was not significant. Antecedent FCs were more frequent (p = 0.03) in patients with MRI-detected MTS (9/39; 23%) vs those with normal MRI (5/62; 8%).

CONCLUSIONS

MRI-detected mesial temporal sclerosis is often encountered in patients with sporadic benign temporal lobe epilepsy.

Isolated Mn12 Single-Molecule Magnets Grafted on Gold Surfaces via Electrostatic Interactions

Electrostatic interactions drive the adsorption of polycationic single-molecule magnets onto anionic monolayers self-assembled on gold surfaces. Well-isolated magnetic clusters have been deposited and characterized using scanning tunneling microscopy and X-ray photoemission spectroscopy.

Mutations and polymorphisms of the CLCN2 gene in idiopathic epilepsy

The authors analyzed the CLCN2 chloride channel gene in 112 probands with familial epilepsy, detecting 18 common polymorphisms. Two brothers with generalized epilepsy and their asymptomatic father, and a father and son with focal epilepsy carried variants of possible functional significance that were not found in 192 controls. The authors conclude that CLCN2 mutations may be a rare cause of familial epilepsy. Further studies are needed to test if polymorphisms in this gene are associated with epilepsy.