Local bandgap control of germanium by silicon nitride stressor

We have proposed a new approach to tune the operation wavelength of Franz-Keldysh Ge electro-absorption modulation in Si photonics by controlling the local strain environment to cover the whole range of C + L bands (1.53 - 1.62 μm). The present paper shows a proof of strain-tuning modulator concept by the shift of the Ge absorption edge using SiN(x) stressor films and Franz-Keldysh effect in strain-controlled Ge.

Karyotype reorganization with conserved genomic compartmentalization in dot-shaped microchromosomes in the Japanese mountain hawk-eagle (Nisaetus nipalensis orientalis, Accipitridae)

The karyotype of the Japanese mountain hawk-eagle (Nisaetus nipalensis orientalis) (2n = 66) consists of a large number of medium-sized and small chromosomes but only 4 pairs of dot-shaped microchromosomes, in contrast to the typical avian karyotype with a small number of macrochromosomes and many indistinguishable microchromosomes. To investigate the drastic karyotype reorganization in this species, we performed a molecular cytogenetic characterization employing chromosome in situ hybridization and molecular cloning of centromeric heterochromatin. Cross-species chromosome painting with chicken chromosome-specific probes 1-9 and Z and a paint pool of 20 microchromosome pairs revealed that the N. n. orientalis karyotype differs from chicken by at least 13 fissions of macrochromosomes and 15 fusions between microchromosomes and between micro- and macrochromosomes. A novel family of satellite DNA sequences (NNO-ApaI) was isolated, consisting of a GC-rich 173-bp repeated sequence element. The NNO-ApaI sequence was localized to the C-positive centromeric heterochromatin of 4 pairs of microchromosomes, which evolved concertedly by homogenization between the microchromosomes. These results suggest that the 4 pairs of dot-shaped microchromosomes have retained their genomic compartmentalization from other middle-sized and small chromosomes.

Significant Compatibility Does Not Exist at the HLA-DQB Gene Locus in Couples With Unexplained Recurrent Abortions

The polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) method was used for both examining compatibility at the HLA-DQB1 gene locus and determining HLA-DQ antigen polymorphism in spouses of unexplained recurrent abortions. Genomic DNA samples were prepared from peripheral mononuclear cells from patient and control couples. Two hundred and thirty base pair fragments of the second exon of the HLA-DQB genes were selectively amplified. Amplified DNAs were digested with the restriction endonucleases, Fok I, Hae III, Hha I, Rsa I and Sau3A I, and subjected to electrophoresis in a polyacrylamide gel. The RFLPs showed that habitual aborters and their husbands had neither significantly frequent alleles nor shared common alleles at the HLA-DQB locus when compared to the control group. Since significant HLA-DQB compatibility was not observed between the spouses and unexplained recurrent aborters, in order to determine whether or not HLA compatibility is responsible for the genesis of unexplained recurrent abortions, it is imperative to further examine the compatibility between other HLA gene loci.

Posterior interosseous nerve palsy secondary to pigmented villonodular synovitis of the elbow: case report and review of literature

Local tumor compression is the main mechanical cause of posterior interosseous nerve (PIN) palsy. The reported cases of these tumors do not include that of pigmented villonodular synovitis (PVNS). Here, we report a case of a 53-year-old male with a 9-year history of painless swelling in his left elbow and a few months of progressive weakness in his left hand. Imaging identified the mass, and histological examination of the biopsy specimens revealed PVNS. The mass was compressing the nerve at the arcade of Frohse, and we performed a complete resection of the mass. Following removal of the mass, the patient regained complete function in his left upper extremity, and no local recurrence has been detected after 2 postoperative years. The possibility of PVNS should be considered in the differential diagnosis of PIN palsy.

Diagnostic performance of percutaneous lung biopsy using automated biopsy needles under CT-fluoroscopic guidance for ground-glass opacity lesions

OBJECTIVE

The goal of our study was to evaluate the diagnostic performance of percutaneous lung biopsy under CT-fluoroscopic guidance for ground-glass opacity (GGO) lesions.

METHODS

85 percutaneous needle lung biopsies were performed in 73 patients. Specimens were obtained by core biopsy utilising an automated cutting needle and were evaluated histologically. Final diagnosis was confirmed by independent surgical pathology, independent culture results or clinical follow-up.

RESULTS

Rates of adequate specimens obtained and of precise diagnosis by needle biopsy were 92.9% (79/85) and 90.6% (77/85) of evaluated lung lesions, respectively. Precise diagnosis was achieved in 87.1% (27/31) of lesions ≤10 mm in diameter, 90.0% (36/40) of lesions >10 mm to ≤20 mm and 100.0% (14/14) of lesions >20 mm. Precision in diagnosing GGO lesions according to the GGO component was 73.9% (17/23) for pure GGO lesions and 96.8% (60/62) for part-solid GGO lesions. Obtaining a precise diagnosis did not differ significantly according to the lesion size (p=0.3840), but differences were significant according to the GGO component (p=0.0047). Malignancy was accurately diagnosed in 35 of 36 malignant lesions for which surgery was later performed. The specific cell type determined from specimens obtained by needle biopsy was exactly the same as the final histological diagnosis obtained after surgery in 20 lesions.

CONCLUSION

Tissue-core lung biopsy under CT-fluoroscopic guidance for a GGO lesion provides a high degree of diagnostic accuracy but is less reliable for determining the specific cell type.

ADVANCES IN KNOWLEDGE

Percutaneous lung biopsy under CT-fluoroscopic guidance for GGO is useful in differentiating malignancy.

Distribution of amyloid burden differs between idiopathic normal pressure hydrocephalus and Alzheimer's disease

This study aimed to elucidate the incidence and distribution of the cortical retention of Pittsburgh compound B (PIB) in patients with idiopathic normal pressure hydrocephalus (iNPH) and clarify the differences from those in patients with Alzheimer's disease (AD). Ten patients with iNPH without any clinical signs indicative of AD were enrolled in this study. Cerebral retention of PIB in positron emission tomography (PET) in iNPH patients was compared with those in seven age-matched AD patients. The CSF levels of β-amyloid 1-42 peptide (Aβ42), which inversely decrease with cerebral amyloid burden, were also measured. Three of the ten patients with iNPH showed increased cortical PIB retention. Although the mean cortical SUV ratios were similar, the distribution of PIB retention differed widely between the patients with iNPH and AD. PIB retention was limited to the high-convexity parasagittal areas in iNPH patients, whereas it spread over the frontal and parietotemporal areas in AD. The coronal images of PIB-PET were more informative than conventional transverse images in evaluating the distribution pattern of cortical PIB retention. Two iNPH patients with higher cortical PIB retention had the lowest levels of CSF Aβ42, indicating that PIB retention in iNPH would not reflect a simple delay in PIB clearance but its binding to existing Aβ amyloid in the brain. Our results indicate that iNPH is one of the diseases exhibiting cortical PIB retention. The characteristic distribution of PIB retention in iNPH could be useful in the differential diagnosis between iNPH and AD.

Emergence of highly degenerate excited states in the frustrated magnet MgCr2O4

High degeneracy in ground states leads to the generation of exotic zero-energy modes, a representative example of which is the formation of molecular spin-liquid-like fluctuations in a frustrated magnet. Here we present single-crystal inelastic neutron scattering results for the frustrated magnet MgCr(2)O(4), which show that a common set of finite-energy molecular spin excitation modes is sustained in both the liquid-like phase above magnetic ordering temperature T(N) and an ordered phase with an extremely complex magnetic structure below T(N). Based on this finding, we propose the concept of high degeneracy in excited states, which promotes local resonant elementary excitations. This concept is expected to have ramifications on our understanding of excitations in many complex systems, including not only spin but also atomic liquids, complex order systems, and amorphous systems.

Switching to an L/N-type calcium channel blocker shows renoprotective effects in patients with chronic kidney disease: the Kyoto Cilnidipine Study

OBJECTIVE

This open-label, randomized controlled trial investigated the effects of cilnidipine, an L/N-type calcium channel blocker (CCB), in patients with chronic kidney disease (CKD).

METHODS

Sixty patients with CKD and well-controlled hypertension being treated with a renin- angiotensin system (RAS) inhibitor and an L-type CCB (L-CCB) were randomly assigned either to switch from the L-CCB to cilnidipine after a 4-week observation period or to continue with L-CCB treatment. Blood pressure, heart rate and renal function were monitored for 12 months. Data were available for analysis from 50 patients: 24 from the cilnidipine group and 26 from the L-CCB group.

RESULTS

Blood pressure was well controlled in both groups. After 12 months, proteinuria and heart rate were significantly decreased in the cilnidipine group, but proteinuria increased and heart rate remained unchanged in the L-CCB group. There was a significant positive correlation between the percentage changes in proteinuria and heart rate.

CONCLUSIONS

Cilnidipine has antihypertensive effects equivalent to those of L-CCBs. In patients with CKD, proteinuria can be decreased by switching from an L-CCB to cilnidipine, thereby improving renal function.

Spin-stripe density varies linearly with the hole content in single-layer Bi2+xSr2-xCuO6+y cuprate superconductors

We have performed inelastic neutron scattering measurements on the single-layer cuprate Bi(2+x) Sr(2-x) CuO(6+y) (Bi2201) with x = 0.2, 0.3, 0.4, and 0.5, a doping range that spans the spin-glass to superconducting phase boundary. The doping evolution of low energy spin fluctuations (11 </~ meV) was found to be characterized by a change in the incommensurate modulation wave vector from the tetragonal [110] to [100]/[010] directions, while maintaining a linear relation between the incommensurability and the hole concentration, δ ≈ p. In the superconducting regime, the spectral weight is strongly suppressed below ≈ 4 meV. Similarities and differences in the spin correlations between Bi2201 and the prototypical single-layer system La(2-x) Sr(x)CuO(4) are discussed.

Separation of metals and phosphorus from incinerated sewage sludge ash

Microbial acidification of incinerated sewage sludge ash and dissolution of metals from the acidified ash were investigated using a semi-batch reactor at different solid retention times (SRTs). The average pH values ranged from 0.91 to 1.2 at SRTs longer than 10 days, whereas the reduction of SRT to 4 days resulted in an increase in the pH value to about 2. The dissolution efficiencies of Al, As, Cd, Cu and Mn were greater than 60% at a SRT of 4 days. Moreover, the effect of pH on precipitation of metals and P (dissolution of 80%) in the filtrate removed from the acidified sewage ash suspension, and the separation of phosphorus and the other metals in the filtrate using ethylenediaminetetraacetic acid (EDTA) or ferric ion, were examined. Although neutralisation of the filtrate to a pH of 5 simultaneously precipitated 100% of Al and 80% of P recovered from the acidified sewage ash, the addition of EDTA decreased their precipitation to 70 and 50%, respectively, at the same pH value, which would promote precipitation of P as calcium phosphate. Furthermore, neutralising to a pH of 2.5 after the addition of ferric ion precipitated P separately from Al and heavy metals.

A vasodilating β1 blocker celiprolol inhibits muscular release of uric acid precursor in patients with essential hypertension

Although nonvasodilating β1 blockers increase the levels of uric acid in serum, it is not known whether vasodilating β1 blockers have a similar effect. In the present study, we evaluated the effect of celiprolol on the release of hypoxanthine, a uric acid precursor, from muscles after an exercise. We used the semi-ischemic forearm test to examine the release of lactate (ΔLAC), ammonia (ΔAmm), and hypoxanthine (ΔHX) before and 4, 10, and 60 min after an exercise in 18 hypertensive patients as well as 4 normotensive subjects. Before celiprolol treatment, all the levels of ΔHX and ΔAmm, and ΔLAC were increased by semi-ischemic exercise in hypertensive patients, and the increases were remarkably larger than those in normotensive subjects. Celiprolol decreased both systolic and diastolic pressure. It also decreased the levels of ΔHX and ΔAmm without changes in ΔLAC after an exercise. These findings also were confirmed by summation of each metabolite (ΣΔMetabolites). Celiprolol caused a marginal decrease of serum uric acid, but the difference was not statistically significant. On the other hand, nonvasodilating β1 blockers did not suppress the levels of ΔHX and ΔAmm, whereas they significantly increased ΔLAC after an exercise. Celiprolol improved energy metabolism in skeletal muscles. It suppressed HX production and consequently did not adversely affect serum uric acid levels.

Low vitamin and carotenoid levels are related to cerebral white matter lesions

OBJECTIVES

PURPOSE

To determine the effects of vitamins and carotenoids on brain white matter lesions (WMLs), we examined the associations between WMLs with vitamin and carotenoid levels in Japanese middle-aged and elderly subjects.

SUBJECTS AND METHODS

Four-hundred and sixty-nine healthy participants (male = 317; female = 152) that underwent medical examinations were examined. Deep white matter lesions (DWLs) were detected via magnetic resonance imaging (MRI) in 39 subjects. We evaluated the effects of vitamin and carotenoid levels on DWLs via logistic regression analysis.

RESULTS

Lower gamma-tocopherol levels were significantly associated with DWLs in all subjects. While lower gamma-tocopherol and vitamin C levels were significantly associated with DWLs in males, lower delta-tocopherol levels were associated with DWLs in females. The associations between DWLs and lower gamma- and delta-tocopherol and vitamin C levels were independent of age, hypertension, or smoking. However, the associations between DWLs and lower alfa-tocopherol were not significant following adjustments for smoking.

CONCLUSION

Lower carotenoid and vitamin levels were independently associated with cerebral DWLs in Japanese subjects.

Th17-cells in atopic dermatitis stimulate orthodontic root resorption

OBJECTIVE

The aim of this study was to investigate how atopic dermatitis (AD) contributes to root resorption during orthodontic tooth movement.

MATERIALS AND METHODS

Atopic dermatitis model mice and wild-type mice were subjected to an excessive orthodontic force (OF) to induce movement of the upper first molars. The expression levels of the tartrate-resistant acid phosphatase (TRAP), IL-17, IL-6, and RANKL proteins were determined in the periodontal ligament (PDL) by an immunohistochemical analysis. Furthermore, the effects of the compression force on co-cultures of CD4(+) cells from AD patients or healthy individuals and human PDL cells were investigated with regard to the levels of secretion and mRNA expression of IL-17, IL-6, RANKL, and osteoprotegerin.

RESULTS

The immunoreactivities for TRAP, IL-17, IL-6, and RANKL in the AD group were found to be significantly increased. The double immunofluorescence analysis for IL-17/CD4 detected immunoreaction. The secretion of IL-17, IL-6, and RANKL, and the mRNA levels of IL-6 and RANKL in the AD patients were increased compared with those in healthy individuals.

CONCLUSION

Th17 cells may therefore be associated with the deterioration of root resorption of AD mice, and may explain why AD patients are more susceptible to root resorption than healthy individuals when an excessive OF is applied.

Lymphadenectomy around the left renal vein in Siewert type II adenocarcinoma of the oesophagogastric junction

BACKGROUND

The extent of lymphadenectomy in patients with Siewert type II adenocarcinoma of the oesophagogastric junction is controversial. The aim of this study was to investigate lymph node involvement around the left renal vein.

METHODS

Lymph node involvement and prognosis in patients with Siewert type II cancers treated by R0-1 surgical resection were investigated, with regard to lymphadenectomy around the left renal vein. Based on the incidence of involvement at each node, the node stations were divided into three tiers (first tier, more than 20 per cent involvement; second tier, 10-20 per cent involvement; third tier, less than 10 per cent involvement).

RESULTS

Of 150 patients with type II oesophagogastric adenocarcinoma, 94 had left renal vein lymphadenectomy. The first lymph node tier included nodes along the lesser curvature, right cardia, left cardia and left gastric artery, with involvement of 28·0-46·0 per cent and a 5-year survival rate of 42-53 per cent in patients with positive nodes. The nodes around the lower mediastinum, left renal vein, splenic artery and coeliac axis constituted the second tier, with involvement of 12·7-18 per cent and a 5-year survival rate of 11-35 per cent. With regard to the left renal vein, the incidence of involvement was 17 per cent and the 5-year rate survival rate was 19 per cent. Multivariable analysis showed that left renal vein lymphadenectomy was an independent prognostic factor in patients with pathological tumour category pathological T3-4 disease (hazard ratio 0·51, 95 per cent confidence interval 0·26 to 0·99; P = 0·048).

CONCLUSION

Left renal vein nodal involvement is similar to that seen along the splenic artery, in the lower mediastinum and coeliac axis, with similar impact on patient survival.

Radiographic and pathological analysis of small lung adenocarcinoma using the new IASLC classification

AIM

To analyse the correlation between computed tomography (CT) findings of small lung adenocarcinomas and the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society Classification of Lung Adenocarcinoma.

MATERIALS AND METHODS

A retrospective review of 300 lung adenocarcinoma lesions (size ≤20 mm) after surgical resection in 295 consecutive patients was performed. Tumours were defined as air-containing type if the ratio of the maximum dimension of the tumour on mediastinal windows to the maximum dimension of the tumour on lung windows was ≤50%, and as solid-density type if the ratio was >50%. The incidence between CT findings (air bronchogram, vascular involvement, pleural tags, notches, and spiculation) and pathological findings were investigated.

RESULTS

Of the 142 air-containing lesions, 114 were adenocarcinoma in situ (AIS), 28 were minimally invasive adenocarcinoma (MIA), and none of the lesions were invasive adenocarcinoma. Of the 158 solid-density lesions, 30 were AIS, 24 were MIA, and 104 were invasive adenocarcinoma. Notches and pleural tags were commonly observed in cases of invasive adenocarcinoma (p < 0.05).

CONCLUSIONS

In the air-containing type of small lung adenocarcinomas, AIS and MIA were observed but no cases of invasive adenocarcinoma were found. The presence of notches and pleural tags were a significant factor in invasive adenocarcinoma.

Possible association of nicotinic acetylcholine receptor gene (CHRNA4 and CHRNB2) polymorphisms with nicotine dependence in Japanese males: an exploratory study

INTRODUCTION

Smoking is a leading global cause of avoidable mortality. It has been reported that the nicotinic acetylcholine receptor (CHRNA4 and CHRNB2) genes might be associated with smoking behavior in several ethnic populations. However, no study between the 2 genes and nicotine dependence (ND) using a Japanese population has been reported.

METHODS

We examined the association between ND and 5 single nucleotide polymorphisms (SNPs) within the CHRNA4 and 3 SNPs within the CHRNB2 using a well characterized sample of 558 Japanese healthy male workers with a relatively homogeneous background. The Fagerström test for nicotine dependence (FTND) was used to quantify the degree of ND. Additionally, we explored the effect of gene-gene interactions of the 2 genes on ND.

RESULTS

We found CHRNB2 rs4845652 genotypes to be associated with FTND scores under an additive genetic model: rs4845652 T-allele carriers had lower ND levels (p=0.038; when adjusted for smoking duration: p=0.052). Furthermore, we demonstrated a possible gene-gene interaction of CHRNA4 and CHRNB2 on ND in a dose-dependent manner: those smokers with CHRNA4 rs1044397 GG or GA genotypes along with CHRNB2 rs4845652 CC genotype are likely to demonstrate higher ND scores.

DISCUSSION

These findings suggest that CHRNB2 rs4845652 T-allele carriers may be associated with lower levels of ND, and that certain allelic combinations of CHRNA4 and CHRNB2 might be correlated with higher ND levels. This preliminary study has certain limitations (issues such as sample size/power and multiple testing) that need to be taken into account, and the present work thus has an experimental nature.

Growth suppression and mitotic defect induced by JNJ-7706621, an inhibitor of cyclin-dependent kinases and aurora kinases

Aurora kinases and cyclin-dependent kinases, which play critical roles in the cell cycle and are frequently overexpressed in a variety of tumors, have been suggested as attractive targets for cancer therapy. JNJ-7706621, a recently identified dual inhibitor of these kinases, is reported to induce cell cycle arrest, endoreduplication, and apoptosis. In the present study, we further investigated the molecular mechanisms underlying these effects. The inhibitor arrested various cells at G2 phase at low concentration, and at both G1 and G2 phases at high concentration. JNJ-7706621 did not prevent localization of Aurora A to the spindle poles, but did inhibit other centrosomal proteins such as TOG, Nek2, and TACC3 in early mitotic phase. Similarly, the drug did not prevent localization of Aurora B to the kinetochore, but did inhibit other chromosomal passenger proteins such as Survivin and INCENP. In the cells exposed to JNJ-7706621 after nocodazole release, Aurora B, INCENP, and Survivin became relocated to the peripheral region of chromosomes, but Plk1 and Prc1 were localized on microtubules in later mitotic phase. Treatment of nocodazole-synchronized cells with JNJ-7706621 was able to override mitotic arrest by preventing spindle checkpoint signaling, resulting in failure of chromosome alignment and segregation. Injection of the drug significantly inhibited the growth of TC135 Ewing's sarcoma cells transplanted into athymic mice by cell cycle arrest and apoptosis. JNJ-7706621 is a unique inhibitor regulating cell cycle progression at multiple points, suggesting that it could be useful for cell cycle analysis and therapy of various cancers, including Ewing's sarcoma.

Stimulation of monoclonal antibody production by human-human hybridoma cells with an elevated concentration of potassium or sodium phosphate in serum-free medium

Potassium or sodium phosphate was found to stimulate the production of human monoclonal antibody by human-human hybridoma HB4C5. The addition of 15 mM Na-phosphate (pH 7.4) into serum-free culture medium increased the antibody production up to 4-fold, when seeded at cell density of 1×10(5) cells/ml in dishes. At the higher cell density of 5×10(5) cells/ml, K-phosphate was more effective than Na-phosphate, at the same concentration. In large-scale continuous culture, the addition of 10 mM Na-phosphate into serum-free culture medium stimulated antibody production by HB4C5 cells 6-fold.

Marked alteration of c-fos and c-jun but not hsp70 messenger RNA expression in rat brain after cold-induced trauma: An in situ hybridization study

Immediate early gene (IEG) mRNA induction by cryogenic injury was examined using an in situ hybridization approach and the results compared with the heat shock protein mRNA expression. Hybridization signals for c-fos and c-jun mRNA were found after 30 min in the ipsilateral cortex, the hippocampal dentate granule cells and the piriform cortex, c-jun mRNA was also detected in the contralateral dentate gyrus and the piriform cortex, but was less extensive. Return to baseline values was observed at the 24 h time point. Peak induction, with silver grains observed mainly over the neurons on emulsion autoradiograms, was demonstrated in all cases 30 min to 1 h post-injury. In contrast, only slight hsp70 mRNA expression by the neurons surrounding the cold-injured site could be detected by microautoradiography, at 6 h following the trauma. The results indicate that cryogenic brain injury induces IEGs in a similar way to mechanical modes of injury such as lateral fluid percussion, but that hsp70 mRNA is hardly expressed, implying the possible existence of differences in stress response pathways.

Egg yolk lipoprotein, a new supplement for the growth of mammalian cells in serum-free medium : Egg yolk lipoprotein for serum-free growth of cells

Egg yolk lipoprotein promoted growth of a wide variety of mammalian cell lines, including plasma-cytomas and epithelial cell lines, in serum-free medium. The lipoprotein was active for cell growth when used with insulin, transferrin, ethanolamine and selenite. The most active lipoprotein fraction (YLP-pI7.5) was purified to give a single peak by chromatofocusing and gel filtration, and was homogeneous on a 0.35% agarose gel electrophoretogram. The lipoprotein was characterised as a very low density lipoprotein with a protein content of only 1.3%. This lipoprotein had an optimal concentration of 300 μg/ml (4 μg protein/ml). It was easily separable from proteinous molecules secreted into the serum-free medium by the cells, since it floated on the surface of the medium after addition of ammonium sulfate, to precipitate protein, and centrifugation. An associated structure of lipid and protein seemed to be still necessary for the lipoprotein to exhibit a growth promoting activity.

Purification and characterization of lymphocytic clonal growth factor (LCGF) derived from human-human hybridoma SH-76 cells

Human-human hybridoma SH-76 cells were found to produce a factor that supported the growth of lymphocytic cells at low densities. The factor was purified from serum-free conditioned medium of the hybridoma cells by a successive application of ammonium sulfate precipitation, DEAE-Toyopearl, TSK G3000 SW and DEAE-5PW column chromatograph. The purified factor was a 72K single protein. The factor showed marked growth stimulating effect on lymphocytic cell lines, but had no effect on the growth of human adhesive cancer cell lines. Thus, the factor is a lymphocytic clonal growth factor (LCGF), as found previously in human plasma (Miyata, 1988). The LCGF of SH-76 cells could be produced in growth factor-free RPMI medium and purified easily from the conditioned medium. The factor is inactivated by heating at over 80°C, but is much more stable than the LCGF in human plasma.

Current-induced magnetic domain wall motion below intrinsic threshold triggered by Walker breakdown

Controlling the position of a magnetic domain wall with electric current may allow for new types of non-volatile memory and logic devices. To be practical, however, the threshold current density necessary for domain wall motion must be reduced below present values. Intrinsic pinning due to magnetic anisotropy, as recently observed in perpendicularly magnetized Co/Ni nanowires, has been shown to give rise to an intrinsic current threshold J(th)(0). Here, we show that domain wall motion can be induced at current densities 40% below J(th)(0) when an external magnetic field of the order of the domain wall pinning field is applied. We observe that the velocity of the domain wall motion is the vector sum of current- and field-induced velocities, and that the domain wall can be driven against the direction of a magnetic field as large as 2,000 Oe, even at currents below J(th)(0). We show that this counterintuitive phenomenon is triggered by Walker breakdown, and that the additive velocities provide a unique way of simultaneously determining the spin polarization of current and the Gilbert damping constant.