Ultra low κ PECVD Porogen Approach: Matrix Precursors Comparison and Porogen Removal Treatment Study

The introduction of new dielectrics into silicon chip interconnection technology is necessary to increase electrical performance. Sub-65nm technologies need κ values below 2.5 and the main way to reduce the dielectric constant is to introduce porosity. This work reports results concerning a two steps PECVD porogen approach to perform Ultra Low κ (κ <2.5). The first step is an hybrid material deposition: i.e. an a-SiOC:H matrix containing organic sacrificial inclusions (porogen phase). In the second step, the porogen is removed by a suitable curing to generate porosity. Two siloxane precursors (decamethylcyclopentasiloxane and diethoxymethylsilane) were evaluated as matrix precursors. Their influences, as well as O2 addition in plasma gas feed, in terms of cross-linking and incorporation were evaluated by FTIR analysis. Thermal anneal and UV treatment (thermally assisted) were evaluated as a curing second step. It allows to better understand this critical step which combines porogen removal and material cross-linking. By optimizing deposition and curing parameters, κ value lower than 2.4 were obtained.

A first-in-human phase I trial of PBI-05204 (oleandrin), an inhibitor of Akt, FGF-2, NF-Kb, and p70S6K in advanced solid tumor patients

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Background: PBI-05204 contains oleandrin, a cardiac glycoside, which inhibits the α-3 subunit Na-K ATPase pump. Over-expression of the α-3 subunit in malignant cells correlates with the tumor proliferation. Oleandrin inhibits FGF- 2 export and activation of NF-Kβ and inhibits phosphorylation of Akt. PBI-05204 also inhibits p70S6K, decreasing mTOR activity. In this ongoing study of PBI-05204, we sought to determine the DLTs, MTD and recommended phase II dose in advanced solid tumors patients (pts) and to characterize its’ pharmacokinetics (PK) and pharmacodynamics (PD). Methods: This was a standard 3+3 phase I design. PBI-05240 was given orally for 21 days of 28 days. Dose was increased by 100% if no related grade 2 adverse event (AE) was observed and increased by 50% if a grade 2 AE occurred. If no other grade 2 AE were observed then subsequent dose escalation was resumed at 100%. In order to determine drug-mediated changes in pAkt, p70S6K, and S6 (mTOR effectors) expression as a surrogate marker of target effect, peripheral blood mononuclear cells (PBMCs) were obtained in addition to PKs. Results: To date 15 pts have received PBI-05204 at 5 dose levels (0.6 mg to 10.2 mg/day), 2 pts are currently active at dose level 5. No DLT has been observed thus far. 10 out of 15 pts (67%) experienced only grade 1 AEs, most common: fatigue and constipation (20%). No significant cardiac toxicities have been observed, only first degree AV block and grade 2 PVC's. Of the 15 evaluable pts, 3 had stable disease for > 4 months, with bladder, colorectal, and fallopian tube cancer pts having an 11, 16, and 10% reduction by RECIST respectively. PKs initially show dose-dependent peak plasma oleandrin concentrations are reached at 2–4 hr following administration with > 50% cleared in 6 hrs. Western blots of PBMCs showed PBI-05204 markedly reduced phosphorylation of Akt, p70S6K, and S6 in a time dependent manner in 4 pts (1 at dose level 2, and 3 and 2 at dose level 5). Reduction of these effectors was observed concomitantly with relatively higher levels of Na, K-ATPase α-3 subunit expression. Conclusions: PBI-05204 is tolerated up to 10.2/mg/day with very little AE's or cardiotoxicity. Initial response evaluation shows activity in diverse tumors with PD analysis suggesting target effect.

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Postnatal electrical and morphological abnormalities in lumbar motoneurons from transgenic mouse models of amyotrophic lateral sclerosis

Antidromically identified lumbar motoneurons intracellularly recorded in the entire brainstem/spinal cord preparation isolated from SOD1(G85R) postnatal mice (P3-P10) were labelled with neurobiotin and fully reconstructed in 3D from serial sections in order to analyse their morphology. This staining procedure revealed differences between WT and SOD1(G85R) dendritic trees for most metric and topologic parameters analyzed. A highly complex morphology of SOD1(G85R) motoneurons dendrites (increased number of branching points and terminations) was found and the dendritic trees were longer compared to the WT motoneurons. These morphological changes observed in P8-P9 motoneurons mice occurred concomitantly with a decrease in the input resistance and gain. During electrophysiological recordings, four patterns of discharge were observed in response to ramp stimulations, that were equally distributed in WT and SOD1(G85R) motoneurons. In slice preparation, whole cell patch-clamp recordings made from developing motoneurons in SOD1(G85R) and double transgenic SOD1(G93A)/Hb9-eGFP mice showed that Riluzole, a blocker of persistent inward sodium conductance, altered the repetitive firing in a similar way for the 2 strains. These results show that the SOD1 mutations linked to familial ALS alter the development of the electrical and morphological properties of lumbar motoneurons.

Significance of stress myocardial perfusion scans in predicting cardiovascular events and mortality in cancer patients

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Background: Cardiac risk assessment in cancer patients has not extensively been studied. We evaluated the role of stress myocardial perfusion scan (SMPS) in predicting cardiovascular outcomes in cancer patients. Methods: A retrospective chart review was performed on 787 patients who had a SMPS from 01/2002 - 03/2003. All patients were followed for at least 1.5 years. Cox proportional hazard model was used to determine the time-to-first event [cardiac death, myocardial infarction (MI) and coronary revascularization]. Cardiac death was defined as documented cardiac death or sudden unexplained death. Results: A total of 501/787 (64%) patients had normal SMPS, whereas 286/787 (36%) had abnormal SMPS. Adenosine [430/787 (55%)] and dobutamine [144/787 (14%)] were used for chemical stress while 213/787 (23%) patients underwent exercise testing. Mean age was 66±11 years and median follow-up duration was 1.8 years. The 3- year event-free survival rate was 0.71 (0.64–0.78) for abnormal SMPS and 0.87 (0.8–0.94) for normal SMPS (p<0.0001). Of all abnormal scans (n=286), 3-year event free-survival rate based on type of vascular defects varied from 0.79(0.67–0.93) for fixed defects, 0.68 (0.58-.08) for reversible defects and 0.63 (0.5–0.8) for co-existent fixed and reversible defects (p<0.0001). Other factors adversely affecting event-free survival were male gender (p=0.025), cardiomyopathy (p=0.001), coronary artery disease (p<0.0001), previous MI (p<0.0001), congestive heart failure (p=0.001) and hypercholesterolemia (p<0.0001). When we analyzed cardiac death as a separate event, SMPS results still made a significant difference with 3-year cardiac-survival rate of 0.79 (0.69–0.91) for abnormal scan group versus 0.88 (0.81–0.95) for normal scan group (p=0.05). Furthermore, the 3-year cardiac-survival rate in patients with both fixed and reversible defects was 0.4 (0.1–1), which was much worse than those with fixed [0.87 (0.76–0.99)] or reversible [0.85 (0.74–0.99)] defects alone (p=0.028). Conclusions: SMPS is a highly useful modality for predicting cardiac events and mortality in cancer patients. The characteristics of the perfusion defect further stratifies the patients at higher risk.

No significant financial relationships to disclose.