Neuropathic Pain Features in Patients with Bone Metastases.

AIMS: The results of previous randomised controlled trials suggest that radiation oncologists should consider the presence of neuropathic pain when they prescribe dose fractionations for painful bone metastases. Although validated screening tools for neuropathic pain features are currently available, the prevalence of such features among patients with painful bone metastases is still poorly understood. The purpose of this study was to estimate the prevalence of neuropathic pain features among patients who received palliative radiotherapy for painful bone metastases. MATERIALS AND METHODS: We conducted a cohort survey of consecutive patients who received palliative radiotherapy for painful bone metastases at St Luke's International Hospital between 2013 and 2014. Patients were prospectively assessed before radiotherapy using the validated screening questionnaire to identify neuropathic pain components in Japanese patients. Pain with neuropathic features was prospectively defined using the total score of the seven-item questionnaire and a cut-off score ≥9. The pain response was assessed 2 months after the start of radiotherapy according to the criteria defined by the International Bone Metastases Consensus Working Party. RESULTS: Eighty-seven patients were assessed. Twenty-four per cent of patients (95% confidence interval: 16-35%) were diagnosed as having pain with neuropathic features. On multivariate analysis, no significant correlations were seen between neuropathic pain features and patient characteristics. Sixty-four patients (74%) were assessable 2 months after the start of radiotherapy. Overall response rates were 59% (95% confidence interval: 33-82%) in patients with neuropathic features and 55% (95% confidence interval: 40-70%) in those without such features. CONCLUSIONS: A considerable proportion of the patients were proven to have bone pain with neuropathic features. Further investigations are warranted to validate symptom assessment tools in cooperation with pain distribution and image findings, and to clarify if the presence of neuropathic pain affects the response to palliative radiotherapy.

Efficient transfer of synthetic ribozymes into cells using hemagglutinating virus of Japan (HVJ)-cationic liposomes. Application for ribozymes that target human t-cell leukemia virus type I tax/rex mRNA.

We investigated the usefulness of ribozymes in inhibiting the expression of human T-cell leukemia virus type I (HTLV-I) gene. Two hammerhead ribozymes that were against HTLV-I rex (RR) and tax (TR) mRNA were synthesized. Both ribozymes were sequence-specific in the in vitro cleavage analysis of run-off transcripts from tax/rex cDNA. Intracellular activities of the ribozymes were studied in HTLV-I tax cDNA-transfected rat embryonic fibroblasts (Rat/Tax cells), which expressed the Tax but not Rex. Ribozymes were delivered into cells using anionic or cationic liposomes fused with hemagglutinating virus of Japan (HVJ). Cellular uptake of ribozymes complexed with HVJ-cationic liposomes was 15-20 times higher cellular uptake than naked ribozymes, and 4-5 times higher than that of ribozymes complexed with HVJ-anionic liposomes. HVJ-cationic liposomes promoted accumulation of ribozymes in cytoplasm and accelerated transport to the nucleus. Tax protein levels were decreased about 95% and were five times lower when the same amount of TR was introduced into the cells using HVJ-cationic, rather than HVJ-anionic liposomes. Inactive ribozyme and tax antisense oligodeoxynucleotides reduced Tax expression by about 20%, whereas RR and tax sense oligodeoxynucleotides had no effect. These results suggest that the ribozymes' effect against tax mRNA was sequence-specific, and HVJ-cationic liposomes can be useful for intracellular introduction of ribozymes.

Terahertz-rate optical pulse generation from a passively mode-locked semiconductor laser diode.

We report what is to our knowledge the first demonstration of terahertz-rate optical pulse generation by harmonic passive mode locking in a distributed-Bragg-reflector laser diode. Along with the fundamental repetition rate of 38.8 GHz, we observed 400-GHz, 800-GHz, and 1.54-THz harmonics, depending on the bias condition of gain section. The pulse envelope for 1.54-THz pulses was in good agreement with a calculation from the Fourier transformation of the optical spectrum, indicating that the output pulses are transform limited.

Successive excited-state absorption through a multistep process in highly Er(3+) -doped fiber pumped by a 1.48-microm laser diode.

The fluorescence spectra ranging from 400 to 1000 nm were investigated on highly Er(3+) -doped fiber pumped by a 1.48-microm laser diode. A strong green emission was observed. An investigation of the fluorescence intensity dependence on pump power revealed that the green emission is attributed to successive excited-state absorption through a three-step process and also that saturation of the atomic levels that contribute to the emission occurs.