P04.04 Optimizing dasatinib for glioblastoma treatment

BACKGROUND

Glioblastoma is the most common primary malignancy of the central nervous system with a dismal prognosis, even with surgical and chemoradiotherapy. Expression profiling studies classify IDH-wildtype Glioblastoma into three subtypes: Proneural (PN), mesenchymal (MES) and classical (CL). A promising target to inhibit in Glioblastoma is the non-receptor tyrosine kinase and proto-oncogene SRC. After robust pre-clinical results, SRC inhibitors like dasatinib did not improve survival of Glioblastoma patients after recurrence in clinical trials.

MATERIAL AND METHODS

Consolidating efforts to personalize cancer therapy, we use in silico analyses backed by in vitro and in vivo experiments on Glioblastoma stem-like cells (GSCs) derived from primary patient tumors to present a novel stratification strategy for dasatinib therapy in glioblastoma. To further tackle dasatinib resistance in GSCs, a pooled shRNA library against 5000 genes was combined with dasatinib to identify genes whose knockdown sensitizes GSCs to dasatinib. This was integrated with proteomics and phosphoproteomics data of dasatinib inhibited GSCs.

RESULTS

We found MES tumors with high expression of SERPINH1 to be sensitive to dasatinib inhibition, compared to the CL and PN subtypes. Interestingly, SRC phosphorylation status did not predict the efficacy of dasatinib inhibition. Computational analyses integrating data from the loss-of-function dropout viability screen and proteomics/phosphoproteomics using a novel modification of the SamNet algorithm identified Wee1, a tyrosine kinase involved in cell-cycle signaling, as a potential combination inhibition target with dasatinib. Further validation experiments showed a robust synergistic effect through combination of dasatinib and the wee1 inhibitor, MK-1775 in PN GSCs.

CONCLUSION

This study highlights strategies to optimize dasatinib treatment in different glioblastoma subtypes. While the stratification of patients harboring mesenchymal glioblastoma with SERPINH1 overexpression could provide an option in this particular subtype, combining dasatinib or other SRC inhibitors with Wee1 inhibitors could present an additional possibility for treating resistant proneural tumors

Effect of Prolonged Pressure on Hemodynamics of Sacral Tissues Assessed by Diffuse Optical Imaging: A Pilot Study

Pressure injuries (PIs) are wounds resulting from prolonged pressure exerting on the skin and underlying tissues over bony prominences (e.g., lower back, heels, shoulders) in bed-bound patients and wheelchair users. Minimizing pressure has long been considered the most effective preventative method, and current guidelines require visual skin inspection and repositioning every two hours. However, these strategies are often applied deficiently and do not adequately prevent PIs from becoming penetrating wounds. Recent studies attribute the development of PIs to cell deformation, inflammatory, and ischemic damages that cumulatively propagate from the microscale (death of few cells) to the macroscale (tissue necrosis) within one to several hours. Although the nature of the PI pathogenesis is complex and multifactorial, measuring tissue alterations in real-time may elucidate the origination mechanism and ultimately allow detecting PIs at the earliest stage. In this pilot study, we evaluated the ability of diffuse optical imaging (DOI) to assess hemodynamic changes resulting from prolonged pressure on the sacral tissues in five healthy volunteers laying immobile in a supine position for 2 hours. A thin, body-conforming optical imaging probe encompassing 256 optodes arranged in a regularly spaced grid over a 160 × 160 mm area was used to construct DOI volumetric images representing changes of oxyhemoglobin (HbO₂) and deoxyhemoglobin (HHb) concentration from a zeroed baseline. After 2 hours of continuous body weight pressure, hemodynamic images in all subjects were substantially dissimilar from their individual baseline. We also found that hemodynamic similarity computed pairwise across subjects exhibited a high value and limited variability around the mean, thus denoting a consistent level of image similarity across subjects. These preliminary results indicate that prolonged pressure causes distinctive hemodynamic patterns that can be effectively investigated with DOI and that monitoring functional changes over time holds potential for clarifying the development mechanisms of PIs.

Tests of General Relativity with GW170817

The recent discovery by Advanced LIGO and Advanced Virgo of a gravitational wave signal from a binary neutron star inspiral has enabled tests of general relativity (GR) with this new type of source. This source, for the first time, permits tests of strong-field dynamics of compact binaries in the presence of matter. In this Letter, we place constraints on the dipole radiation and possible deviations from GR in the post-Newtonian coefficients that govern the inspiral regime. Bounds on modified dispersion of gravitational waves are obtained; in combination with information from the observed electromagnetic counterpart we can also constrain effects due to large extra dimensions. Finally, the polarization content of the gravitational wave signal is studied. The results of all tests performed here show good agreement with GR.

Constraining the p-Mode-g-Mode Tidal Instability with GW170817

We analyze the impact of a proposed tidal instability coupling p modes and g modes within neutron stars on GW170817. This nonresonant instability transfers energy from the orbit of the binary to internal modes of the stars, accelerating the gravitational-wave driven inspiral. We model the impact of this instability on the phasing of the gravitational wave signal using three parameters per star: an overall amplitude, a saturation frequency, and a spectral index. Incorporating these additional parameters, we compute the Bayes factor (lnB_{!pg}^{pg}) comparing our p-g model to a standard one. We find that the observed signal is consistent with waveform models that neglect p-g effects, with lnB_{!pg}^{pg}=0.03_{-0.58}^{+0.70} (maximum a posteriori and 90% credible region). By injecting simulated signals that do not include p-g effects and recovering them with the p-g model, we show that there is a ≃50% probability of obtaining similar lnB_{!pg}^{pg} even when p-g effects are absent. We find that the p-g amplitude for 1.4  M_{⊙} neutron stars is constrained to less than a few tenths of the theoretical maximum, with maxima a posteriori near one-tenth this maximum and p-g saturation frequency ∼70  Hz. This suggests that there are less than a few hundred excited modes, assuming they all saturate by wave breaking. For comparison, theoretical upper bounds suggest ≲10^{3} modes saturate by wave breaking. Thus, the measured constraints only rule out extreme values of the p-g parameters. They also imply that the instability dissipates ≲10^{51}  erg over the entire inspiral, i.e., less than a few percent of the energy radiated as gravitational waves.

Search for Subsolar-Mass Ultracompact Binaries in Advanced LIGO's First Observing Run

We present the first Advanced LIGO and Advanced Virgo search for ultracompact binary systems with component masses between 0.2  M_{⊙}-1.0  M_{⊙} using data taken between September 12, 2015 and January 19, 2016. We find no viable gravitational wave candidates. Our null result constrains the coalescence rate of monochromatic (delta function) distributions of nonspinning (0.2  M_{⊙}, 0.2  M_{⊙}) ultracompact binaries to be less than 1.0×10^{6}  Gpc^{-3}  yr^{-1} and the coalescence rate of a similar distribution of (1.0  M_{⊙}, 1.0  M_{⊙}) ultracompact binaries to be less than 1.9×10^{4}  Gpc^{-3}  yr^{-1} (at 90% confidence). Neither black holes nor neutron stars are expected to form below ∼1  M_{⊙} through conventional stellar evolution, though it has been proposed that similarly low mass black holes could be formed primordially through density fluctuations in the early Universe and contribute to the dark matter density. The interpretation of our constraints in the primordial black hole dark matter paradigm is highly model dependent; however, under a particular primordial black hole binary formation scenario we constrain monochromatic primordial black hole populations of 0.2  M_{⊙} to be less than 33% of the total dark matter density and monochromatic populations of 1.0  M_{⊙} to be less than 5% of the dark matter density. The latter strengthens the presently placed bounds from microlensing surveys of massive compact halo objects (MACHOs) provided by the MACHO and EROS Collaborations.

GW170817: Measurements of Neutron Star Radii and Equation of State

On 17 August 2017, the LIGO and Virgo observatories made the first direct detection of gravitational waves from the coalescence of a neutron star binary system. The detection of this gravitational-wave signal, GW170817, offers a novel opportunity to directly probe the properties of matter at the extreme conditions found in the interior of these stars. The initial, minimal-assumption analysis of the LIGO and Virgo data placed constraints on the tidal effects of the coalescing bodies, which were then translated to constraints on neutron star radii. Here, we expand upon previous analyses by working under the hypothesis that both bodies were neutron stars that are described by the same equation of state and have spins within the range observed in Galactic binary neutron stars. Our analysis employs two methods: the use of equation-of-state-insensitive relations between various macroscopic properties of the neutron stars and the use of an efficient parametrization of the defining function p(ρ) of the equation of state itself. From the LIGO and Virgo data alone and the first method, we measure the two neutron star radii as R_{1}=10.8_{-1.7}^{+2.0}  km for the heavier star and R_{2}=10.7_{-1.5}^{+2.1}  km for the lighter star at the 90% credible level. If we additionally require that the equation of state supports neutron stars with masses larger than 1.97  M_{⊙} as required from electromagnetic observations and employ the equation-of-state parametrization, we further constrain R_{1}=11.9_{-1.4}^{+1.4}  km and R_{2}=11.9_{-1.4}^{+1.4}  km at the 90% credible level. Finally, we obtain constraints on p(ρ) at supranuclear densities, with pressure at twice nuclear saturation density measured at 3.5_{-1.7}^{+2.7}×10^{34}  dyn cm^{-2} at the 90% level.

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω_{0}^{T}<5.58×10^{-8}, Ω_{0}^{V}<6.35×10^{-8}, and Ω_{0}^{S}<1.08×10^{-7} at a reference frequency f_{0}=25  Hz.

GW170817: Implications for the Stochastic Gravitational-Wave Background from Compact Binary Coalescences

The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude Ω_{GW}(f=25  Hz)=1.8_{-1.3}^{+2.7}×10^{-9} with 90% confidence, compared with Ω_{GW}(f=25  Hz)=1.1_{-0.7}^{+1.2}×10^{-9} from binary black holes alone. Assuming the most probable rate for compact binary mergers, we find that the total background may be detectable with a signal-to-noise-ratio of 3 after 40 months of total observation time, based on the expected timeline for Advanced LIGO and Virgo to reach their design sensitivity.

First Search for Nontensorial Gravitational Waves from Known Pulsars

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.

Prospects for observing and localizing gravitational-wave transients with Advanced LIGO, Advanced Virgo and KAGRA

We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and [Formula: see text] credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5-[Formula: see text] requires at least three detectors of sensitivity within a factor of [Formula: see text] of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral

On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0×10^{4}  years. We infer the component masses of the binary to be between 0.86 and 2.26  M_{⊙}, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17-1.60  M_{⊙}, with the total mass of the system 2.74_{-0.01}^{+0.04}M_{⊙}. The source was localized within a sky region of 28  deg^{2} (90% probability) and had a luminosity distance of 40_{-14}^{+8}  Mpc, the closest and most precisely localized gravitational-wave signal yet. The association with the γ-ray burst GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. Subsequent identification of transient counterparts across the electromagnetic spectrum in the same location further supports the interpretation of this event as a neutron star merger. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology.

GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence

On August 14, 2017 at 10∶30:43 UTC, the Advanced Virgo detector and the two Advanced LIGO detectors coherently observed a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes, with a false-alarm rate of ≲1 in 27 000 years. The signal was observed with a three-detector network matched-filter signal-to-noise ratio of 18. The inferred masses of the initial black holes are 30.5_{-3.0}^{+5.7}M_{⊙} and 25.3_{-4.2}^{+2.8}M_{⊙} (at the 90% credible level). The luminosity distance of the source is 540_{-210}^{+130}  Mpc, corresponding to a redshift of z=0.11_{-0.04}^{+0.03}. A network of three detectors improves the sky localization of the source, reducing the area of the 90% credible region from 1160   deg^{2} using only the two LIGO detectors to 60  deg^{2} using all three detectors. For the first time, we can test the nature of gravitational-wave polarizations from the antenna response of the LIGO-Virgo network, thus enabling a new class of phenomenological tests of gravity.

GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10∶11:58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2_{-6.0}^{+8.4}M_{⊙} and 19.4_{-5.9}^{+5.3}M_{⊙} (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, a mass-weighted combination of the spin components perpendicular to the orbital plane, χ_{eff}=-0.12_{-0.30}^{+0.21}. This result implies that spin configurations with both component spins positively aligned with the orbital angular momentum are disfavored. The source luminosity distance is 880_{-390}^{+450}  Mpc corresponding to a redshift of z=0.18_{-0.07}^{+0.08}. We constrain the magnitude of modifications to the gravitational-wave dispersion relation and perform null tests of general relativity. Assuming that gravitons are dispersed in vacuum like massive particles, we bound the graviton mass to m_{g}≤7.7×10^{-23}  eV/c^{2}. In all cases, we find that GW170104 is consistent with general relativity.

Upper Limits on the Stochastic Gravitational-Wave Background from Advanced LIGO's First Observing Run

A wide variety of astrophysical and cosmological sources are expected to contribute to a stochastic gravitational-wave background. Following the observations of GW150914 and GW151226, the rate and mass of coalescing binary black holes appear to be greater than many previous expectations. As a result, the stochastic background from unresolved compact binary coalescences is expected to be particularly loud. We perform a search for the isotropic stochastic gravitational-wave background using data from Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. The data display no evidence of a stochastic gravitational-wave signal. We constrain the dimensionless energy density of gravitational waves to be Ω_{0}<1.7×10^{-7} with 95% confidence, assuming a flat energy density spectrum in the most sensitive part of the LIGO band (20-86 Hz). This is a factor of ∼33 times more sensitive than previous measurements. We also constrain arbitrary power-law spectra. Finally, we investigate the implications of this search for the background of binary black holes using an astrophysical model for the background.

Directional Limits on Persistent Gravitational Waves from Advanced LIGO's First Observing Run

We employ gravitational-wave radiometry to map the stochastic gravitational wave background expected from a variety of contributing mechanisms and test the assumption of isotropy using data from the Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. We also search for persistent gravitational waves from point sources with only minimal assumptions over the 20-1726 Hz frequency band. Finding no evidence of gravitational waves from either point sources or a stochastic background, we set limits at 90% confidence. For broadband point sources, we report upper limits on the gravitational wave energy flux per unit frequency in the range F_{α,Θ}(f)<(0.1-56)×10^{-8}    erg cm^{-2} s^{-1} Hz^{-1}(f/25  Hz)^{α-1} depending on the sky location Θ and the spectral power index α. For extended sources, we report upper limits on the fractional gravitational wave energy density required to close the Universe of Ω(f,Θ)<(0.39-7.6)×10^{-8}  sr^{-1}(f/25  Hz)^{α} depending on Θ and α. Directed searches for narrowband gravitational waves from astrophysically interesting objects (Scorpius X-1, Supernova 1987 A, and the Galactic Center) yield median frequency-dependent limits on strain amplitude of h_{0}<(6.7,5.5,  and  7.0)×10^{-25}, respectively, at the most sensitive detector frequencies between 130-175 Hz. This represents a mean improvement of a factor of 2 across the band compared to previous searches of this kind for these sky locations, considering the different quantities of strain constrained in each case.

Disease characteristics, treatment patterns, and outcomes of follicular lymphoma in patients 40 years of age and younger: an analysis from the National Lymphocare Study†

BACKGROUND

Follicular lymphoma (FL) is the most common indolent non-Hodgkin lymphoma, with median age at diagnosis in the seventh decade. FL in young adults (YAs), defined as diagnosis at ≤40 years, is uncommon. No standard approaches exist guiding the treatment of YA FL, and little is known about their disease characteristics and outcomes. To gain further insights into YA FL, we analyzed the National LymphoCare Study (NLCS) to describe characteristics, initial treatments, and outcomes in this population versus patients aged >40 years.

PATIENTS AND METHODS

Using the NLCS database, we stratified FL patients by age: 18-40 (YA), 41-60, 61-70, 71-80, and >80 years. Survival probability was estimated using Kaplan-Meier methodology. We examined associations between age and survival using hazard ratios and 95% confidence intervals (CIs) from multivariable Cox models.

RESULTS

Of 2652 eligible FL patients in the NLCS, 164 (6%) were YAs. Of YA patients, 69% had advanced disease, 80% had low-grade histology, and 50% had good-risk disease according to the Follicular Lymphoma International Prognostic Index (FLIPI). Nineteen percent underwent observation, 12% received rituximab monotherapy, and 46% received chemoimmunotherapy [in 59% of these: R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone)]. With a median follow-up of 8 years, overall survival (OS) at 2, 5, and 8 years was 98% (95% CI 93-99), 94% (95% CI 89-97), and 90% (95% CI 83-94), respectively. Median progression-free survival (PFS) was 7.3 years (95% CI 5.6-not reached).

CONCLUSIONS

In one of the largest cohorts of YA FL patients treated in the rituximab era, disease characteristics and outcomes were similar to patients aged 41-60 years, with favorable OS and PFS in YAs. Longer-term outcomes and YA-specific survivorship concerns should be considered when defining management. These data may not support the need for more aggressive therapies in YA FL.

CLINICAL TRIAL NUMBER

Roche/Genentech ML01377 (U2963n).

Abstract 745: A non-redox reactive allosteric inhibitor of MAPK phosphatases with selective toxicity to human cancer cells

Mitogen-activated protein kinase phosphatases (MKPs) are members of a family of dual specificity phosphatases (DUSPs) that regulate cellular signaling homeostasis by dephosphorylating mitogen-activated kinases, key mediators of cell death and survival. The archetype MKP, DUSP1 (also termed MKP-1/CL100), is overexpressed in ovarian, breast, and prostate cancers and found elevated in the “oncogenic signature” of RAS mutant tumor cells. DUSP1 mediates cancer cell migration and invasion, and protects cells from apoptosis by clinically used antineoplastic agents and gamma-irradiation. Despite the evidence that DUSP1 is a promising anticancer target, efforts to discover small molecule inhibitors have been largely unsuccessful. The MKP active site is shallow and contains a catalytic cysteine that is sensitive to oxidation. Hence, prior discovery screens have mostly identified redox-reactive structures with promiscuous biological activities. Using a zebrafish chemical screen, we recently discovered a new DUSP inhibitory chemotype that has no redox-reactive structural features and that is thought to bind to an allosteric site adjacent to the catalytic cavity. Structure-activity relationship studies in transgenic zebrafish identified an analog (VNK-215) that retained DUSP1 and DUSP6 inhibitory activity but was well tolerated by the developing embryo. Here we hypothesized that VNK-215 could be selectively cytotoxic to cancer cells due to its ability to inhibit DUSP1 and lack of redox-reactive features. We found that in MDA-MB-231 human breast cancer cells, VNK-215 had apoptotic and antimigratory activity at concentrations that inhibited DUSP1 in mammalian cells, and induced phosphorylation of the DUSP1 substrates ERK, p38, and JNK. Studies in primary rat hepatocytes and live zebrafish embryos revealed that VNK-215, unlike previously described DUSP inhibitors, did not induce reactive oxygen species, mitochondrial damage, or toxicity. Our data suggest that the promiscuous activities of existing DUSP inhibitors are the cause of redox reactivity rather than target inhibition, and posit that DUSP1 is a druggable anticancer target for small molecule allosteric inhibitors.

Citation Format: Laura Vollmer, Lawrence Vernetti, Ahmet Bakan, Vasiliy Korotchenko, Ivet Bahar, Billy Day, Michael Tsang, Andreas Vogt. A non-redox reactive allosteric inhibitor of MAPK phosphatases with selective toxicity to human cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 745. doi:10.1158/1538-7445.AM2014-745

Complex changes in the liver mitochondrial proteome of short chain acyl-CoA dehydrogenase deficient mice

Short-chain acyl-CoA dehydrogenase (SCAD) deficiency is an autosomal recessive inborn error of metabolism that leads to the impaired mitochondrial fatty acid β-oxidation of short chain fatty acids. It is heterogeneous in clinical presentation including asymptomatic in most patients identified by newborn screening. Multiple mutations have been identified in patients; however, neither clear genotype-phenotype relationships nor a good correlation between genotype and current biochemical markers for diagnosis has been identified. The definition and pathophysiology of this deficiency remain unclear. To better understand this disorder at a global level, quantitative alterations in the mitochondrial proteome in SCAD deficient mice were examined using a combined proteomics approach: two-dimensional gel difference electrophoresis (2DIGE) followed by protein identification with MALDI-TOF/TOF and iTRAQ labeling followed by nano-LC/MALDI-TOF/TOF. We found broad mitochondrial dysfunction in SCAD deficiency. Changes in the levels of multiple energy metabolism related proteins were identified indicating that a more complex mechanism for development of symptoms may exist. Affected pathways converge on disorders with neurologic symptoms, suggesting that even asymptomatic individuals with SCAD deficiency may be at risk to develop more severe disease. Our results also identified a pattern associated with hepatotoxicity implicated in mitochondrial dysfunction, fatty acid metabolism, decrease of depolarization of mitochondria and mitochondrial membranes, and swelling of mitochondria, demonstrating that SCAD deficiency relates more directly to mitochondrial dysfunction and alteration of fatty acid metabolism. We propose several candidate molecules that may serve as markers for recognition of clinical risk associated with this disorder.

Multifocal motor neuropathy and muscle hypertrophy

Multifocal motor neuropathy is frequently an asymmetrical neuropathy predominantly affecting the upper limbs. Patients present with weakness, fasciculations and distal muscle wasting. Hypertrophy of muscles is very infrequently reported. We present two cases of multifocal motor neuropathy with upper limb muscle hypertrophy and discuss possible pathophysiological mechanisms. Botulinum toxin may be useful to alleviate cramp.

Knowledge and attitudes about hepatitis C virus (HCV) infection and its treatment in HCV mono-infected and HCV/HIV co-infected adults

Hepatitis C virus (HCV) treatment is rapidly changing but little is known about patients' attitudes and knowledge about HCV. This study used a cross-sectional survey to examine the relationship between HCV knowledge and attitudes towards HCV in patients with HCV mono-infection and HIV/HCV co-infection. Subsequently, an education intervention was developed with an abridged version of the cross-sectional survey administered before and after the education session to assess changes in knowledge and attitudes. 292 people participated in the cross-sectional survey, and 87 people participated in the education intervention. In the cross-sectional survey, the mean knowledge score regarding HCV was low (<50% of the total possible score). Mono-infected and co-infected individuals shared similar knowledge deficits and attitudes towards HCV despite having distinct demographic differences. Attitudes endorsed by patients included the following: 57% feared the consequences of HCV on their life, 37% felt HCV was not fatal, 27% did not believe they needed HCV medication, 21% felt ashamed of having HCV and 16% felt HCV treatment was not important. Attitudes that reflected indifference and shame towards HCV were associated with lower knowledge scores (HCV knowledge score of 15.1 vs. 17.5, P < 0.01 for indifference and 15.3 vs. 17.2 for shame, P = 0.02). The education intervention improved knowledge scores but did not modify the assessed attitudes. Intervention studies are needed to effectively change attitudes towards HCV infection and treatment.

Development of neuropathy in patients (pts) with multiple myeloma (MM) treated with thalidomide (thal)—Patterns of occurrence and the role of electrophysiologic monitoring

7618

Background: Given new treatment options for pts with MM, physicians are faced with the dilemma of how best to sequence these drugs in order to optimize efficacy and toxicity. Peripheral neuropathy frequently limits the duration of treatment (Rx) with thal. In this study we assessed the utility of serial nerve electrophysiological studies (NES) to detect the onset of neuropathy, and assessed the time course of occurrence and possible clinical and Rx-related predictive factors. Methods: 75 pts with relapsed/refractory MM were enrolled in a multi-centre trial of thal. In addition to clinical assessment, pts underwent sensory and motor NES at baseline and every 3 months in order to identify neuropathy. We examined the value of baseline and serial NES for development of neuropathy, with time to development of neuropathy according to clinical or NES criteria compared using Kaplan-Meier analysis. Differences between pt and Rx-related variables were compared using a Mann-Whitney U-test or a Fisher’s exact test. Results: Thirty nine percent had some NES abnormalities at baseline. Pts were treated with thal at a median dose intensity of 373 mg/day and followed for a median of 18 months (range 6–26). Thirty-one of the 75 pts (41%) developed neuropathy during thal Rx, with 11 (15%) ceasing thal due to neuropathy. The actuarial incidence of any neuropathy increased from 38% at 6 months to 73% at 12 months with 81% of responding pts developing this complication. The use of NES did not reliably predict the imminent development of clinical neuropathy requiring cessation of thal. Nor were pt age, gender or type of prior therapy (ie vincristine) predictive. Development of neuropathy was related to duration of thal exposure with a median time of 268 days thal in those who developed neuropathy compared to 89 days in those who did not (p = 0.0001). Cumulative dose or dose intensity received were not predictive. Conclusions: The majority of pts will develop peripheral neuropathy given sufficient length of thal Rx and to minimize the risk of neurotoxicity, therapy should be limited to less than six months. NES monitoring provides no clear benefit over careful clinical evaluation for the development of clinically significant neuropathy.

[Table: see text]

316 SUPPLEMENTAL CYSTEINE PRESENCE DURING THE DECONDENSATION OF SPERM CHROMATIN IMPROVES FERTILIZATION AND BLASTOCYST FORMATION AFTER INTRACYTOPLASMIC SPERM INJECTION IN PIGS

The effect of a cysteine supplement in culture media for oocytes matured in vitro after intracytoplasmic sperm injection (ICSI) on fertilization and embryo development were examined. In the first experiment, sperm injected oocytes were cultured in NCSU23 (control) or NCSU23 supplemented with 0.57–3.71 mM cysteine (0.57–3.71 Cys) for 12 h after ICSI, and then fixed to observe pronuclear formation. In the second experiment, to examine the appropriate duration time of cysteine supplement to support fertilization, sperm-injected oocytes were transferred into NCSU23 following culture in NCSU23 supplemented with 1.71 mM cysteine for 1, 2, 3, 4, 5, 6, or 9 h after ICSI, and then fixed at 12 h. At the same time, morphological changes of sperm heads in oocytes cultured in NCSU23 (1.71 Cys) were observed. In the third experiment, to examine the developmental ability of ICSI embryos fertilized in NCSU23 (1.71 Cys), sperm injected oocytes were cultured under the following conditions for a total of 168 h; NCSU23 (control), NCSU23 (1.71 Cys) for 3 h followed by transfer into NCSU23 (1.71 Cys-3 h), NCSU23 (1.71 Cys) for 12 h followed by transfer in NCSU23 (1.71 Cys-12 h), or NCSU23 (1.71 Cys) (1.71 Cys). Data were pooled from at least five replicates. Values in each replicate were analyzed using one-way ANOVA. Significance of differences was assessed by Student's t-test. Culture with several concentrations of cysteine for 12 h showed that 1.71–3.71 Cys significantly (P < 0.05) increased fertilization rates above controls or 0.57 Cys (56–60%, 35%, or 48%, respectively). Culture for several duration times with 1.71 Cys showed that fertilization rates increased as the duration time increased to 3 h which was significantly (P < 0.05) higher than controls (68% and 34%, respectively), and culture times of greater than 3 h did not increase fertilization rates (58–68%). At 3 h, 59% of oocytes cultured in NCSU23 (1.71 Cys) had decondensed sperm heads and 16% of those had enlarged sperm heads. At 6 h, 50% of oocytes cultured in NCSU23 (1.71 Cys) had male pronuclei. Blastocyst formation rate in 1.71 Cys-3 h was 29% which was higher than for controls (20%). On the other hand, 1.71 Cys-12 h cultures showed low blastocyst formation rates, and continuous culture in NCSU23 (1.71 Cys) for 168 h (1.71 Cys) significantly (P < 0.05) decreased blastocyst rates (16% and 7%, respectively). We found that the supplement of 1.71 mM cysteine to NCSU23 for culture of oocytes after ICSI improved fertilization rates. However, the presence of 1.71 mM cysteine for 12 h or longer after ICSI had adverse effects on embryo development. Since 1.71 mM cysteine supplement for 3 h after ICSI improved blastocyst formation with the same fertilization rates as when supplemented for 12 h, the presence of cysteine only during the decondensation of sperm chromatin was found to be associated with the improvement of fertilization and also the promotion of blastocyst formation.

Autologous peripheral blood stem cell transplantation for peripheral neuropathy secondary to monoclonal gammopathy of unknown significance

A 40-year-old patient presented with rapidly progressing peripheral neuropathy secondary to monoclonal gammopathy of unknown significance (MGUS). He became severely debilitated, being wheelchair-bound, despite treatment with chemotherapy, intravenous immunoglobulin and plasma exchange. He was subsequently treated with high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (PBSCT). He has made remarkable recovery at 12 months post transplantation. We propose that high-dose chemotherapy and autologous PBSC transplantation may have a role in the treatment of severe, progressive and treatment-resistant MGUS-related peripheral neuropathy.

Combined pre- and post-surgical bupivacaine wound infiltrations decrease opioid requirements after knee ligament reconstruction

PURPOSE

To test the efficacy of a combination of selective pre- and post-surgical local anesthetic infiltrations of the knee, compared with standard intra-articular injection at the end of surgery alone, to reduce postoperative opioid requirements following arthroscopic cruciate ligament reconstruction (ACLR).

METHODS

In a double-blind, randomized, controlled trial, we studied 23 patients (ASA I or II) scheduled for elective ACLR under general anesthesia. The treatment group (n = 12) received infiltrations with bupivacaine 0.25% with epinephrine 1:200,000 presurgically (10 ml into the portals, 10 ml at the medial tibial incision site, 10 ml at the lateral femoral incision site, and 10 ml intra-articularly) and postsurgically (5 ml at the medial tibial incision and 10 ml at the lateral femoral incision). The control group (n = 11) received infiltrations with saline 0.9% in the same manner. All patients received a standard intra-articular local anesthetic instillation of the knee (25 ml of bupivacaine 0.25% with epinephrine 1:200,000) at the completion of surgery.

RESULTS

Postoperative opioid requirements were lower in the treatment group (5.8 +/- 2.9 mg morphine equivalent) than in the control group ( 13.7 +/- 5.8 mg; P = 0.008). Treatment patients were ready for discharge approximately 30 min earlier than control patients (P = 0.046). There were no adverse events in the treatment group. In the control group, 2/11 patients vomited and a third experienced transient postoperative diaphoresis, dizziness and pallor.

CONCLUSION

We conclude that a combination of selective pre- and post-surgical wound infiltration with bupivacaine 0.25% provides superior analgesia compared with a standard post-surgical intra-articular injection alone.