Differential effects of voltage-gated calcium channel blockers on calcium channel alpha-2-delta-1 subunit protein-mediated nociception

BACKGROUND

Overexpression of the voltage-gated calcium channel (VGCC) alpha-2-delta1 subunit protein (Cav α2 δ1 ) has been shown to cause pain states. However, whether VGCC are involved in pain states driven by abnormal Cav α2 δ1 expression is not known.

METHODS

Intrathecal injection of N-, P/Q- and L-type VGCC blockers were tested in two models: a transgenic neuronal Cav α2 δ1 overexpression (TG) model with behavioural hypersensitivity and a spinal nerve ligation (SNL) model with Cav α2 δ1 overexpression in sensory pathways and neuropathy pain states.

RESULTS

The nociceptive response to mechanical stimuli was significantly attenuated in both models with ω-conotoxin GVIA (an N-type VGCC blocker) and nifedipine (an L-type VGCC blocker), in which ω-conotoxin GVIA appeared more potent than nifedipine. Treatments with ω-agatoxin IVA (P-VGCC blocker), but not ω-conotoxin MVIIC (Q-VGCC blocker) had similar potency in the TG model as the N-type VGCC blocker, while both ω-agatoxin IVA and ω-conotoxin MVIIC had minimal effects in the SNL model compared with controls.

CONCLUSION

These findings suggest that, at the spinal level, N- and L-type VGCC are likely involved in behavioural hypersensitivity states driven by Cav α2 δ1 overexpression. Q-type VGCC has minimal effects in both models. The anti-nociceptive effects of P-type VGCC blocker in the Cav α2 δ1 TG mice, but minimally at the SNL model with presynaptic Cav α2 δ1 up-regulation, suggest that its potential action site(s) is at the post-synaptic and/or supraspinal level. These findings support that N-, L- and P/Q-type VGCC have differential contributions to behavioural hypersensitivity modulated by Cav α2 δ1 dysregulation at the spinal cord level.

Treatments, complications, and healthcare utilization associated with acromegaly: a study in two large United States databases

The economic burden of acromegaly in the US has been largely unknown. We describe the prevalence of treatment patterns, complication rates, and associated healthcare utilization and costs of acromegaly in the US. Patients were identified between 1/1/2002 and 12/31/2009 in claims databases. During 1-year after each continuously-enrolled patient's first acromegaly claim, pharmacy and medical claims were used to estimate outcomes. Regression models were used to adjust outcomes. There were 2,171 acromegaly patients (mean age: 45.3 years; 49.7% female); 77.8% received the majority of their care from non-endocrinologists. Pharmacologic treatment was used by 30.8% of patients: octreotide-LAR in 18.6%, dopamine agonists in 9.8%, short-acting octreotide in 4.7%, pegvisomant in 4.1%, and lanreotide in 1.2%; 56% had biochemical monitoring. Comorbidities were common, ranging from 6.6% (colon neoplasms) to 25.6% (musculoskeletal abnormalities). Mean healthcare costs were $24,900. Adjusted analyses indicated comorbidities increased the odds of hospitalization: by 76% for musculoskeletal abnormalities; 193% for cardiovascular abnormalities; and 56% for sleep apnea (p < 0.05). Odds of emergency department visits increased by 87% (musculoskeletal) and 132% (cardiovascular abnormalities) (p < 0.01). After adjustments, colon neoplasms were associated with $8,401 mean increase in costs; musculoskeletal abnormalities with $7,502, cardiovascular abnormalities with $13,331, sleep apnea with $10,453, and hypopituitarism with $6,742 (p < 0.01). Complications are common and increase utilization and cost in acromegaly patients. Cardiovascular complications nearly tripled the odds of hospitalization (OR 2.93) and increased annual mean cost by $13,331. Adequate management of this disease may be able to reduce health care utilization and cost associated with these complications and with acromegaly in general.

A low-power, high-speed, 9-channel germanium-silicon electro-absorption modulator array integrated with digital CMOS driver and wavelength multiplexer

We demonstrate the first germanium-silicon C-band electro-absorption based waveguide modulator array and echelle-grating-based silicon wavelength multiplexer integrated with a digital CMOS driver circuit. A 9-channel, 10Gbps SiGe electro-absorption wavelength-multiplexed modulator array consumed a power of 5.8mW per channel while being modulated at 10.25Gbps by 40nm CMOS drivers delivering peak-to-peak voltage swings of 2V, achieving a modulation energy-efficiency of ~570fJ/bit including drivers. Performance up to 25Gbps on a single-channel SiGe modulator and CMOS driver is also reported.

Effect of the 12-gene colon cancer assay results on adjuvant treatment recommendations in patients with stage II colon cancer

INTRODUCTION

The 12-gene colon cancer Recurrence Score assay is a clinically validated predictor of recurrence risk in stage II colon cancer patients. A survey was performed characterizing the assay's impact on treatment recommendations for these patients.

METHODS

US medical oncologists (n = 346) who ordered the assay for ≥3 stage II colon cancer patients were asked to complete a web-based survey regarding their most recent such patient. Physicians surveyed represented users of the assay within the first 2 years of commercial availability which may include 'early adopters'.

RESULTS

Most of 116 eligible physicians were in community practice (86%), with median 14.5 years' experience (range = 2-40). Mean patient age was 61 years (range = 32-85); 81% had T3 disease, and 38% had comorbidities. Of 76 patients tested for mismatch-repair/microsatellite-instability (MMR/MSI), 13 (17%) were MMR-deficient/MSI-high; 46 (61%) MMR-proficient/MSI-low; and 17 (22%) unknown. Most patients (84%) had ≥12 nodes examined. Median Recurrence Score result was 20 (range = 1-77). Before assay, treatment recommendations were specified for 92 (79%) patients, with no recommendation for 24 (21%). Of the 92 with pre-assay recommendations, chemotherapy was planned for 52 (57%) and observation for 40 (43%); the assay changed recommendations for 27 (29%). Treatment intensity decreased for 18 (67%) and increased for nine (33%) patients; it was more likely to decrease for lower Recurrence Score values and increase for higher values (p < 0.001).

CONCLUSION

For stage II colon cancer patients receiving Recurrence Score testing, 29% of treatment recommendations were changed. Use of the assay may lead to reductions in treatment intensity. Study limitations include retrospective design, data gathering during the first 2 years of assay availability only, and potential non-representativeness of respondents.

AMPK activation regulates neuronal structure in developing hippocampal neurons

AMP-activated protein kinase (AMPK) is a serine/threonine kinase that functions as a cellular and whole organism energy sensor to regulate ATP-consuming (anabolic) and ATP-generating (catabolic) pathways. The heterotrimeric AMPK complex consists of a catalytic α-subunit, regulatory β-subunit, and an AMP/ATP-binding γ-subunit. Several alternate isoforms exist for each subunit (α1, α2, β1, β2, γ1, γ2 and γ3). However, little is known of the expression pattern or function of the individual catalytic complexes in regulating neuronal structure. In this study, we examined the role of AMPK subunits in differentiating hippocampal neurons. We found that during development, the expression of AMPK subunits increase and that activation of AMPK by energetic stress inhibits neuronal development at multiple stages, not only during axon outgrowth, but also during dendrite growth and arborization. The presence of a single functional AMPK catalytic complex was sufficient to mediate these inhibitory effects of energetic stress. Activation of AMPK mediates these effects by suppressing both the mTOR and Akt signaling pathways. These findings demonstrate that the energy-sensing AMPK pathway regulates neuronal structure in distinct regions of developing neurons at multiple stages of development.

Hyperon-nucleon interactions from quantum chromodynamics and the composition of dense nuclear matter

The low-energy nΣ(-) interactions determine, in part, the role of the strange quark in dense matter, such as that found in astrophysical environments. The scattering phase shifts for this system are obtained from a numerical evaluation of the QCD path integral using the technique of lattice QCD. Our calculations, performed at a pion mass of m(π)~389 MeV in two large lattice volumes and at one lattice spacing, are extrapolated to the physical pion mass using effective field theory. The interactions determined from lattice QCD are consistent with those extracted from hyperon-nucleon experimental data within uncertainties and strengthen model-dependent theoretical arguments that the strange quark is a crucial component of dense nuclear matter.

Impact of dose hot spots on spinal cord tolerance following stereotactic body radiotherapy: a generalized biological effective dose analysis

The purpose of this study was to investigate the effects of high-dose inhomogeneous irradiation to small volumes of spinal cord with a new generalized biological effective dose (gBED) analysis for spine stereotactic body radiotherapy (SBRT). The gBED was applied to spinal cord dosimetric data (contoured per the thecal sac) at specified volumes for a cohort of five patients with radiation-induced myelopathy (RM) and compared to nineteen patients without RM post-SBRT. The spinal cord gBED was calculated and normalized to a conventional 2-Gy equivalent dose fraction scheme (α/β = 2 Gy for late toxicity). Differences between the conventional BED and those gBED calculations by accounting for small-volume dosing within the spinal cord was observed. Statistically significant differences in the mean gBED between the RM group and the non-RM group was observed both at the maximum point volume (gBED of 66 Gy vs. 37 Gy (p = 0.01), respectively) and at the 0.1 cm(3) volume (gBED of 53 Gy vs. 28 Gy (p = 0.01), respectively). No significant difference at the 0.1 cm(3) volume was observed based on the mean BED comparisons. No significant differences were observed at the larger 1 cm(3), 2 cm(3) or 5 cm(3) volumes for either BED or gBED comparisons. We conclude that differences in dose hot spots characteristics within small inhomogenously irradiated volumes of spinal cord can affect spinal cord tolerance following SBRT treatments.

Evidence for a bound H dibaryon from lattice QCD

We present evidence for the existence of a bound H dibaryon, an I=0, J=0, s=-2 state with valence quark structure uuddss, at a pion mass of m(π)∼389  MeV. Using the results of lattice QCD calculations performed on four ensembles of anisotropic clover gauge-field configurations, with spatial extents of L∼2.0, 2.5, 3.0, and 3.9 fm at a spatial lattice spacing of b(s)∼0.123  fm, we find an H dibaryon bound by B(∞)(H)=16.6±2.1±4.6  MeV at a pion mass of m(π)∼389  MeV.

Blind-ending branch of a bifid ureter: multidetector CT imaging findings

A bifid ureter with a blind-ending branch is a rare congenital anomaly. Although typically found incidentally, this anomaly can be symptomatic and radiologists should be aware of this important variant. To our knowledge, there has been no previous report of this anomaly as seen on multidetector CT urography. We present a patient with haematuria and review the clinical significance, radiological findings and embryological aetiology of this anomaly.

Menopausal Hormone Therapy influences Lung Cancer Survival but not Lung Cancer Risk: Results from the California Teachers Study

Purpose: Most studies have shown a protective or null effect of postmenopausal hormone therapy (HT) on lung cancer risk, whereas the recent post-hoc analysis of the Women's Health Initiative (WHI) showed that estrogen+progestin (E+P) decreased lung cancer survival. Given the substantial clinical implications, it is vital that the risk and survival associations be validated.

Methods: We examined the associations between HT use and lung cancer risk and survival among 60,592 postmenopausal women enrolled in the prospective California Teachers Study cohort. Between 1995 and 2007, 727 women (184 never smokers) were diagnosed with lung cancer; 441 of these died as of December 31, 2007. Age-stratified, multivariable Cox proportional hazards regression was used to calculate hazard ratios (HR).

Results: After adjusting for potential confounders, various measures of HT use were not associated with lung cancer risk. However, any HT use (vs. no use) was associated with a statistically significant increase in lung-cancer-specific survival [HR, 0.70; 95% confidence interval (CI), 0.56-0.87]. Among women who only used E, statistically significant increases in lung cancer survival were seen for recent use (HR, 0.59; 95% CI, 0.43-0.80), but not former use; use of only E+P was not associated with survival. Shorter duration of recent E-only use was associated with improved survival (0-5 years of use: HR, 0.29, 95% CI, 0.12-0.68; 5-15 years of use: HR, 0.60, 95% CI, 0.35-1.05; &gt;15 years of use: HR, 0.58, 95% CI, 0.39-0.88) (trend P = 0.005). Similarly, women who reported recently using E-only for 0-5 years had a median survival time of 42.1 months versus women who reported 5-15 years of use (31 months), &gt;15 years of use (19.1 months), or no HT use (15.6 months) (log-rank P = 0.009). Among former users of HT, a statistically significant 63% (95% CI, 0.16-0.87) decrease in lung-cancer-specific death was observed for E-only use &lt;5 years prior to baseline, but not for E-only use &gt;5 years prior to baseline or E+P-only use.

Conclusions: Contrary to the recent finding that lung cancer survival is poorer among women in WHI taking E+P, our results suggest no effect of E+P. By contrast, postmenopausal E-only use, specifically recent use, is associated with increased lung cancer survival.

Oncoplastic Approach for Reconstruction of Large Partial Mastectomy Defects Using Reduction Mammoplasty in Large Breasted Women

Background: Women with large breast tumors are often treated with mastectomy as their definitive operation. However, women with large breasts can have a significant resection and still achieve an excellent aesthetic outcome if the partial mastectomy is combined with a reduction mammoplasty. It is not clear if the limitation for breast conservation should be made based on tumor size, or on the basis of the volume of tissue that needs to be resected relative to the total volume of breast tissue. Our study aims to assess the oncologic safety and cosmetic outcome of large partial mastectomies in large breasted women combined with reduction mammoplasty.Materials and Methods: All patients undergoing partial mastectomy and reduction mammoplasty performed at the University of California San Francisco were included. Medical records were reviewed for demographics, breast cancer data, oncologic and reconstructive operations, postoperative recurrences, complications, and need for additional operations.Results: Sixty-five patients undergoing partial mastectomy and reduction mammoplasty reconstruction were identified. Average tumor size was 2.8 cm (range 0.6 cm to 8.9 cm). The stage distribution for 63 patients was stage 0 (n=11), I (n=15), II (n=24), III (n=10), and IV (n=3), and 2 patients had Phylloides tumor. Twenty-five patients had neoadjuvant therapy, followed by breast reduction as their primary resection once chemotherapy was completed. Twenty patients (30.8%) required re-excision, four of whom required multiple re-excisions. Fifty nine patients (90.8%) were successfully treated with our approach, while 6 patients (9.2%) required completion mastectomy for their definitive resection, based on margin status after initial resection. There were a total of two recurrences, one in a patient who had a local DCIS recurrence after initial presentation with stage 0 disease and one in a patient who presented with metastatic disease. The patient with stage 0 disease and subsequent recurrence did not have radiation; the other patient presented initially with synchronous metastatic disease, had a poor response to chemotherapy, and her local recurrence occurred simultaneously with progression of distant disease. Of the patients with stage 0-III disease, the recurrence rate was 1.6% with a mean follow-up of 13 months. Eleven patients (15.9%) developed postoperative complications, including fat necrosis (n=1), hematoma (n=1), cellulitis (n=2), seroma (n=3), and wound healing complications (n=4). Despite complications and radiation therapy, all patients were exceptionally pleased with their reconstruction.Conclusion: Partial mastectomy with reduction mammoplasty breast reconstruction is a viable option that combines a safe oncologic procedure with immediate breast reconstruction. While further follow-up is needed, it is a viable alternative to mastectomy, enabling breast conservation and correction of significant breast redundancy and ptosis, which can impair the efficacy of radiation therapy. Prospective data collection should continue for these cases to establish the long term outcomes of large-breasted patients undergoing partial mastectomy and reduction mammoplasty.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4125.