Smilagenin attenuates beta amyloid (25-35)-induced degeneration of neuronal cells via stimulating the gene expression of brain-derived neurotrophic factor

The development of drugs that attenuate neurodegeneration is important for the treatment of Alzheimer's disease (AD). We previously found that smilagenin (SMI), a steroidal sapogenin from traditional Chinese medicinal herbs improves memory in animal models, is neither a cholinesterase inhibitor nor a glutamate receptor antagonist, but can significantly elevate the declined muscarinic receptor (M receptor) density. In this article, to clarify whether SMI represents a new approach for treating neurodegeneration disease, we first demonstrate that SMI pretreatment significantly attenuates the neurodegenerative changes induced by beta amyloid 25-35 (Aβ(25-35)) in cultured rat cortical neurons, including decreased cholinergic neuron number, shortened neurite outgrowth length, and declined M receptor density. Brain-derived neurotrophic factor (BDNF) protein levels in the culture medium were also decreased by Aβ(25-35) and significantly elevated by SMI. Parallel experiments revealed that when the trk receptors were inhibited by K252a or the action of BDNF was inhibited by a neutralizing anti-BDNF antibody, the effects of SMI on the Aβ(25-35)-induced neurodegeneration in rat cortical neurons were almost completely abolished. In the all-trans retinoic acid (RA)-differentiated SH-SY5Y neuroblastoma cells, the BDNF transcription rate measured by a nuclear run-on assay was significantly suppressed by Aβ(25-35) and elevated by SMI, but the BDNF degradation rate measured by half-life determination was unchanged by Aβ(25-35) and SMI. Transcript analysis of the SH-SY5Y cells using quantitative RT-PCR (qRT-PCR) showed that the IV and VI transcripts of BDNF mRNA were significantly decreased by Aβ(25-35) and elevated by SMI. Taken together, we conclude that SMI attenuates Aβ(25-35)-induced neurodegeneration in cultured rat cortical neurons and SH-SY5Y cells mainly through stimulating BDNF mRNA transcription implicating that SMI may represent a novel therapeutic strategy for AD.

Photon correlation in single-photon frequency upconversion

We experimentally investigated the intensity cross-correlation between the upconverted photons and the unconverted photons in the single-photon frequency upconversion process with multi-longitudinal mode pump and signal sources. In theoretical analysis, with this multi-longitudinal mode of both signal and pump sources system, the properties of the signal photons could also be maintained as in the single-mode frequency upconversion system. Experimentally, based on the conversion efficiency of 80.5%, the joint probability of simultaneously detecting at upconverted and unconverted photons showed an anti-correlation as a function of conversion efficiency which indicated the upconverted photons were one-to-one from the signal photons. While due to the coherent state of the signal photons, the intensity cross-correlation function g(2)(0) was shown to be equal to unity at any conversion efficiency, agreeing with the theoretical prediction. This study will benefit the high-speed wavelength-tunable quantum state translation or photonic quantum interface together with the mature frequency tuning or longitudinal mode selection techniques.

How do you measure performance as a colonoscopist?

AIM

The aim of this study was to describe an easy and reproducible method of measuring clinical performance in colonoscopy.

METHOD

Data from all endoscopy procedures performed within the main endoscopy unit at Derriford Hospital between January and December 2007 were analysed. Points were allocated for given procedures. A local health economic analysis revealed that at least 8 points (or four colonoscopies) must be performed to meet list costs. The clinical performance was described as a capability index of crude Caecal Intubation Rate (CIR) vs the mean Points Performed/Endoscopy List (points/list).

RESULTS

Overall, 3884 colonoscopies were performed, with a mean crude CIR of 89.6% and 8.3 points/List. Only 7/23 endoscopists consistently met the Joint Advisory Group on Gastrointestinal Endoscopy (JAG) standard in a cost-effective way. An annual colonoscopy rate of ≥ 150 cases was associated with higher points per list (points/list) (P = 0.003). Endoscopists offering ≥ 15% of cases as training cases had significantly higher crude CIRs and points/list (P = 0.051; P = 0.017).

CONCLUSIONS

Clinical performance is a function of quality provided in a cost-effective way. Our capability index is an effective and reproducible way of measuring clinical performance. Training was not associated with reduced volume.

Laser ranging at 1550 nm with 1-GHz sine-wave gated InGaAs/InP APD single-photon detector

We demonstrated a laser ranging system with single photon detection at 1550 nm. The single-photon detector was a 1-GHz sine-wave gated InGaAs/InP avalanche photodiode. In daylight, 8-cm depth resolution was achieved directly by using a time-of-flight approach based on time-correlated single photon counting measurement. This system presented a potential for low energy level and eye-safe laser ranging system in long-range measurement.

Two-bit quantum random number generator based on photon-number-resolving detection

Here we present a new fast two-bit quantum random number generator based on the intrinsic randomness of the quantum physical phenomenon of photon statistics of coherent light source. Two-bit random numbers were generated according to the number of detected photons in each light pulse by a photon-number-resolving detector. Poissonian photon statistics of the coherent light source guaranteed the complete randomness of the bit sequences. Multi-bit true random numbers were generated for the first time based on the multi-photon events from a coherent light source.

Photon-number-resolving detection at 1.04 μm via coincidence frequency upconversion

We demonstrate photon-number-resolving detection based on coincidence frequency upconversion. Pumped by synchronized pulses, the photon signal of the coherent state at 1.04 μm was upconverted into visible replicas with preserved photon number distribution. The upconverted photons were then registered by a silicon multipixel photon counter. The photon-number-resolving performance was improved by reducing the background counts with a synchronous pump as the coincidence gate and reducing the intrinsic parametric fluorescence influence with long-wavelength pumping. A total detection efficiency of 3.7% was achieved with a quite low noise probability per pulse of 0.0002.

Treatment patterns and health care resource utilization of metastatic colorectal cancer (mCRC) patients who received bevacizumab or cetuximab in second-line regimen

525

Background: Targeted therapies such as bevacizumab (BV) and cetuximab (CX) are important treatment options in mCRC. Real-world treatment patterns and resource utilization of mCRC patients (Pts) receiving BV and CX in second-line (2L) treatment are not well studied.

Methods: Pts with mCRC were identified from the PharMetrics pharmacy and medical insurance claims database (2002-2009). Included Pts received BV or CX in 2L therapy. 2L was defined as change in therapy from first-line (1L) at least 4 weeks after 1L initiation. Healthcare resource utilization and costs were evaluated during the 6 months following 2L start.

Results: A total of 2,188 Pts were included in the analysis, including 1,808 2L BV Pts and 380 2L CX Pts. Demographic and baseline characteristics were similar between groups. Pts' mean age was 61 years and 56% were male. Among all study Pts, 34.1% and 2.7% received BV and CX in 1L, respectively. 60.1% of Pts received oxaliplatin-based regimens in 1L. In 2L, irinotecan and oxaliplatin containing regimens were most commonly used. During the 6 months period following 2L therapy start, BV vs. CX Pts incurred significantly lower risk-adjusted total costs (difference: -$10,231, p=0.020) and inpatient costs ($-3,681, p<0.001). Mean targeted therapy cost was significantly higher for CX ($33,425) than BV ($23,622) (-$10,260, p<0.001). BV Pts incurred significantly less inpatient visits (0.5 vs. 0.7, p<0.001) compared to CX Pts and shorter duration of total hospital stay (3.6 vs. 5.6 days, p=0.007).

Conclusions: In 2L treatment of mCRC Pts in the real world setting, BV was most used with oxaliplatin- and irinotecan-based regimens, whereas CX was commonly used with irinotecan-based regimens. Overall, less healthcare resource utilization and costs were observed in patients treated with 2L BV compared to 2L CX. Use of BV in 2L treatment of mCRC was associated with lower number of claims for targeted agents, lower healthcare costs and fewer hospitalizations than CX.

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Time-dependent photon number discrimination of InGaAs/InP avalanche photodiode single-photon detector

We investigated the photon-number-resolving (PNR) performance of the InGaAs/InP avalanche photodiode (APD) as a function of the electric gate width and the photon arrival time. The optimal electric gate width was around 1 ns for PNR measurements in our experiment, which provided a PNR capability up to three photons per pulse when the detection efficiency was ~20%. And the dependence of the PNR performance on the arrival time of the photons showed that the photon number could be better resolved if the photons arrived on the rising edge of the electric gate than on the falling edge. In addition, we found that with the increase of the electric gate width, PNR performance got worse. The observation would be helpful for improving the PNR performance of the InGaAs/InP APD in the gated mode.

The CHOICE trial: adalimumab demonstrates safety, fistula healing, improved quality of life and increased work productivity in patients with Crohn's disease who failed prior infliximab therapy

BACKGROUND

Adalimumab induces and maintains remission in adults with Crohn's disease.

AIM

To evaluate safety, fistula healing, quality of life and work productivity in adalimumab-treated patients who failed infliximab, including primary nonresponders.

METHODS

After a ≥8-week infliximab washout, patients with moderate-to-severe Crohn's disease received open-label adalimumab as induction (160/80 mg at weeks 0/2) and maintenance (40 mg every other week) therapies. At/after 8 weeks, patients with flare/nonresponse could receive weekly therapy. Minimum study duration was 8 weeks, continuing until the commercial availability of adalimumab for Crohn's disease.

RESULTS

Of 673 patients enrolled, 17% were infliximab primary nonresponders and 83% were initial responders. Three percent of patients had serious infections (mainly abscesses). Complete fistula healing was achieved by 34/88 (39%) patients with baseline fistulas. Improvements in quality of life and work productivity were sustained from week 4 to week 24 for all patients, as well as the subgroup of primary nonresponders.

CONCLUSIONS

Blinded clinical trials have shown adalimumab to be both an effective first-line therapy for anti-TNF-naïve patients and an important treatment option for infliximab-refractory or -intolerant patients. This trial presents open-label experience to support further the safety and effectiveness of adalimumab in patients who failed infliximab therapy, including primary nonresponders (NCT00338650).

Low-noise high-speed InGaAs/InP-based single-photon detector

A low-noise high-speed InGaAs/InP-based single-photon detector was demonstrated with a double-self-differencing spike signal cancellation technique. A photon-number resolving method was used to analyze the ratio of avalanche signal to background noise. By adding a post-self-differencing circuit to the pre-self-differencing circuit, the signal to noise ratio was improved by 11.0 dB. The typical error count probability was as low as 2.1% and 6.4% at the detection efficiency of 20.6% and 30.5%, respectively.

Generation of correlated UV and visible rainbows

We demonstrate concurrent frequency up-conversion and down-conversion in a quadratic nonlinear medium for the generation of correlated ultraviolet and visible rainbows with one-to-one angular and spectral correspondence, facilitating generation of continuously tunable and photon-momentum-dependent multi-wavelength UV and visible twin photons.

Fabrication and optical properties of Y2O3: Eu3+ nanofibers prepared by electrospinning

Y(2)O(3): Eu(3+) nanofibers with the average diameter of ~300 nm were in situ fabricated by electrospinning. X-ray diffraction (XRD) pattern confirmed that the Y(2)O(3): Eu(3+) nanofibers were composed of pure body-centered cubic (bcc) Y(2)O(3) phase. High-resolution transmission electron microscopy (HRTEM) results indicated that Y(2)O(3): Eu(3+) nanofibers were constituted of nonspherical crystalline grains, and these crystalline grains were orderly arranged along the axial direction of single nanofiber. These Y(2)O(3): Eu(3+) nanofibers showed a partially polarized photoluminescence (PL). The arrangement of crystalline grains and the mismatch of dielectric constant between Y(2)O(3): Eu(3+) nanofiber and its environment probably contributed together to the polarized PL from Y(2)O(3): Eu(3+) nanofiber.

Photon-number-resolving detection based on InGaAs/InP avalanche photodiode in the sub-saturated mode

We demonstrated a robust spike cancellation by virtue of optical balancing technique for the near-infrared single-photon detection based on InGaAs/InP avalanche photodiode. A 31 dB suppression of the spike noise provided an efficient technique to read out weak avalanche currents at the early built-up, allowing the study on the photon number resolving dynamics of the InGaAs/InP avalanche photodiode. With the detection efficiency varied from 1% to 36%, the avalanche gain was shown to vary from the linear mode to the saturated mode and evidenced as a sub-saturated avalanche state. Multi-photon avalanche saturation was observed at different photon numbers as the avalanche gain varied. A photon-number-resolving detection was achieved with the detection efficiency as high as 36%.

Real world treatment patterns of gastrointestinal stromal tumor patients

e15602

Background: Imatinib is accepted as the standard first-line therapy to treat gastrointestinal stromal tumor (GIST) in patients with unresectable or metastatic disease. In the case of disease progression, physicians may consider increasing imatinib dose or switching to another second-line agent, such as sunitinib. The aim of this study was to analyze the real-world long term treatment patterns of GIST patients. Methods: Two large claims databases from 01/1999 to 03/2008 were combined (MarketScan and Ingenix Impact) to extract patients diagnosed with GIST who initiated on imatinib ≥400 mg/day. Patients were followed from the first observed imatinib prescription to the end of data availability. Patients who dose increased during the study period were defined as dose escalators, while patients who later switched to sunitinib with or without dose escalation were defined as switchers. Kaplan Meier analyses were used to estimate the rate of treatment changes over time including imatinib discontinuation, defined as a lack of imatinib supply for ≥60 days, and switching back to initial treatment. Results: Among the 1,508 GIST patients who initiated on imatinib, 253 patients had a dose increase and 153 patients switched to sunitinib during the study period. 20.1% patients on imatinib discontinued by the end of the first year, and 43.0% discontinued by the end of the third year. Among the 153 switchers, 61 patients had a dose escalation prior to the switch, of which 82.0% reached 800 mg before switching. Among all the switchers, 20.3% switched back to imatinib within 6 months. Conclusions: These claims-based findings on the duration of first-line imatinib therapy of GIST patients supports data on imatinib efficacy in treating GIST from formal clinical research studies. Most of GIST patients who initiated imatinib continued on this therapy without undergoing dose increase or switch to sunitinib. Among switchers, most did not dose escalate before switching and many eventually switched back to imatinib. It appears that physicians tend to not always follow clinical practice guidelines developed based on expert consensus, with respect to decision rules for dose escalation, or for the appropriate time to change kinase inhibitor therapy.

[Table: see text]

Adverse events associated with escalating imatinib versus switching to dasatinib in patients with chronic myelegenous leukemia

7092

Background: After initial therapy with imatinib, some chronic myelegenous leukemia (CML) patients may require dose escalation or switching to another BCR/ABL kinase inhibitor to achieve the desired response. This study compared adverse events associated with either escalation of imatinib or switching to dasatinib. Methods: Two large administrative claims databases were combined (MarketScan and Ingenix Impact) to extract deidentified information on 17,382 patients diagnosed with CML (ICD-9 code: 205.1) from January 1999 to March 2008. 474 patients (dose escalators) had their dose of imatinib increased at some point to >400 mg/day but were never given dasatinib, while 175 patients were switched to dasatinib with or without dose escalation of imatinib (switchers). Patients were followed from the index date to treatment discontinuation or end of eligibility. Cox proportional-hazard models were used to compare the risk of common adverse events (AEs) associated with escalation or switching to dasatinib, controlling for demographics, imatinib treatment patterns, and prior therapies at baseline. Patients with the studied AEs at baseline were excluded from analyses of the corresponding AEs. Results: Switchers experienced significantly higher risk of the following AEs than escalators: fluid retention (HR 3.22 p < 0.0001), pleural effusion (HR 4.90 p < 0.0001), thrombocytopenia (HR 3.25 p = 0.0044), neutropenia (HR 3.40 p = 0.0009), and some non-hematologic adverse events (HR 2.38 p < 0.0001), dyspnea (HR 4.02 p < 0.0001), constipation (HR 5.79 p = 0.0041), nausea and vomiting (HR 2.40 p = 0.0100), and congestive heart failure (HR 5.01 p < 0.0001). No statistically significant differences in risk of other common AEs associated with imatinib and dasatinib were identified. Conclusions: 15.4% of CML patients treated with ≤400mg of imatinib initially either had dose escalation or switch to dasatinib. Significantly more AEs were associated to those who switched to dasatinib than those who dose escalated. Further study is warranted to examine the causality of the difference in these AEs.

[Table: see text]

Treatment patterns of chronic myelogenous leukemia patients with suboptimal responses to imatinib

7090

Background: Imatinib is the first-line therapy for Philadelphia chromosome-positive chronic myelogenous leukemia (CML). Patients with suboptimal responses may have the dose of imatinib escalated or may be switched to an alternative kinase inhibitor such as dasatinib. The aim of this study is to examine the real-world treatment patterns of imatinib and dasatinib in CML patients. Methods: Two large U.S. administrative claims databases from January 1999 to March 2008 were combined (MarketScan and Ingenix Impact) to extract de-identified information of patients diagnosed with CML (ICD-9 code: 205.1) who were initiated on imatinib. Patients were followed from the first observed imatinib prescription to the end of data availability. Patients who increased imatinib dose to >400 mg/day were defined as dose escalators, while patients who initiated on imatinib and further switched to dasatinib were considered as switchers. Rates of imatinib dose escalation and switching to dasatinib were estimated. Kaplan-Meier (KM) survival analyses were used to estimate the rate of imatinib discontinuation, defined as a lack of imatinib supply for at least 90 days. Among switchers, the rate of switching back to imatinib was also estimated using KM survival analysis. Results: Among the 5,159 CML patients initiated with imatinib, 1,144 patients either had dose escalation of imatinib (839) or were switched to dasatinib (305) during the study period. Of the 5,159 patients, 12.1% patients discontinued imatinib by the end of the first year, and 25.4% discontinued by the end of the third year. Among the 305 switchers, 115 (37.7%) had an imatinib dose increase prior to the switch, and 66 (21.6%) were escalated to 800 mg of imatinib before switching. 51 patients (16.7%) had used imatinib for <6 months before switching, and 17.1% switched back to imatinib within 6 months of dasatinib treatment. Conclusions: This study showed that great variability was observed in the real world treatment pattern of CML patients. Most CML patients who initiated on imatinib did not dose increase or switch during the study period. Of those who switched to dasatinib, most did not attempt to increase the dose before switching, and a sizeable portion of patients had to switch back to imatinib.

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The antitumor effects of OSU-HDAC42, a novel histone deacetylase inhibitor, in HER-2-positive breast cancer

e14587

Background: Elevated HER-2/neu expression in primary breast tumors is associated with frequent relapse and poor prognosis. For this reason, HER-2/neu has been actively pursued as a target for novel therapeutic agents. Histone deacetylase inhibitors (HDACi), a new class of antitumor drugs, can downregulate HER2 through hyperacetylation of heat shock protein 90 (hsp90), an important ATP-dependent chaperone that mediates the stability and maturation of a variety of important oncogenic proteins, including HER2, Akt and ERα. In this study, we assess the effects of OSU-HDAC42, a novel orally bioavailable phenylbutyrate-based HDAC inhibitor, on hsp90 and HER2 downregulation. Methods: OSU-HDAC42 was tested for effects on the human breast cancer cell lines BT474, SKBR3, MDA-MB-231 and MCF-7. Assays of cell viability, cell cycle, apoptosis, HER2 expression, phosphorylation, and hsp90 acetylation were performed. Tumor growth was assessed in an orthotopic HER2+ mammary tumor model, using diets ± OSU-HDAC42. Results: SKBR3 (HER2+, ERα-) was the most susceptible to the antiproliferative effects of OSU-HDAC42 after 72 hours of treatment (IC50 = 0.025 μmol/L), followed by BT474 (HER2+, ERα+), MCF-7 (HER2-, ERα+) and MDA-MB-231 (HER2-, ERα-) cells with IC50 values calculated at 0.16, 0.19 and 0.2 μmol/L, respectively, which correlated with the level of inhibition of Hsp90 client protein expression (HER2, Akt). OSU-HDAC42 yields 43- or 65- fold greater cell killing than suberoylanilide hydroxamic acid (SAHA; vorinostat) or MS-275, respectively, and more potently suppresses the levels of Hsp90 client proteins (HER2, ERα and Akt) and induction of apoptosis in HER2+ breast cancer cells. In vivo administration of OSU-HDAC42 resulted in reductions of 76% and 82% in NT5 (HER2+,ER-) tumor mass and volume, respectively, concomitant with tubulin hyperacetylation, increased PARP cleavage, and decreased HER2 levels in OSU-HDAC42 treated mouse tumors. Conclusions: OSU-HDAC42 is a potent inhibitor of HER2+ breast cancer, mediated in part through hsp90 downregulation. As an orally bioavailable HDAC inhibitor with greater potency than other clinically available HDACi agents, OSU- HDAC42 warrants evaluation in clinical trials as a novel therapy for HER2+ breast cancer.

[Table: see text]