Young's double-slit experiment with undulator vortex radiation in the photon-counting regime.

Young's double-slit interference experiments with undulator vortex radiation were conducted, focusing on photon-counting regime. To isolate the second harmonic radiation in the ultraviolet range emitted from the helical undulator and achieve successful counting measurements, an ultranarrow bandpass filter was utilized under an extremely low-current mode of the electron storage ring. It was observed that the photon spots on the detector, after passing through the double slits, appeared to be randomly distributed. However, upon integrating these photon spots, it was confirmed that interference fringes with characteristic features of optical vortices, such as dark and broken/distorted stripes in the center, were formed. The reproducibility of these interference fringes was confirmed by calculating the optical path difference for the optical vortex reaching the double slits, as well as the optical path difference resulting from normal double-slit interference. Consequently, these findings indicate that even in the state of a single photon, the radiation emitted spontaneously by a high-energy electron in spiral motion possesses the nature of an optical vortex, characterized by a spiral wavefront.

Rugged bialkali photocathodes encapsulated with graphene and thin metal film.

Protection of free-electron sources has been technically challenging due to lack of materials that transmit electrons while preventing corrosive gas molecules. Two-dimensional materials uniquely possess both of required properties. Here, we report three orders of magnitude increase in active pressure and factor of two enhancement in the lifetime of high quantum efficiency (QE) bialkali photocathodes (cesium potassium antimonide (CsK2Sb)) by encapsulating them in graphene and thin nickel (Ni) film. The photoelectrons were extracted through the graphene protection layer in a reflection mode, and we achieved QE of ~ 0.17% at ~ 3.4 eV, 1/e lifetime of 188 h with average current of 8.6 nA under continuous illumination, and no decrease of QE at the pressure of as high as ~ 1 × 10-3 Pa. In comparison, the QE decreased drastically at 10-6 Pa for bare, non-protected CsK2Sb photocathodes and their 1/e lifetime under continuous illumination was ~ 48 h. We attributed the improvements to the gas impermeability and photoelectron transparency of graphene.

Retrospective analysis of non-anaplastic peripheral T-cell lymphoma in pediatric patients in Japan.

BACKGROUND: Reports of non-anaplastic peripheral T-cell lymphoma (PTCL) in pediatric patients are relatively rare. PROCEDURE: We performed a retrospective analysis in patients with PTCL over an 18-year period (1991-2008). RESULTS: We could analyze clinical data in 21 patients with non-anaplastic PTCL; 10 were female and 10 male. Median age of onset was 11 years (range: 1-21 years). There were nine patients with PTCL, not otherwise specified (PTCL-NOS); ten with extranodal NK/T-cell lymphoma, nasal type; one with angioimmunoblastic T-cell lymphoma; and one with subcutaneous panniculitis-like T-cell lymphoma. Initial lesions involved cervical lymph nodes in five patients, and the skin in five patients. In five patients, hemophagocytic syndrome (HPS) was the initial clinical feature. There were 12 patients with advanced stage disease (stages III and IV). Chemotherapy and radiation was administered in 18 and 2 patients, respectively. Among the two patients who did not receive chemotherapy and radiation, one patient died while being treated for HPS but another improved spontaneously. Although 5 patients relapsed, 18 of 21 patients remained alive without disease at last follow-up. Five-year overall survival rate was 85.2%. CONCLUSIONS: Generally, the outcome results of conventional chemotherapy for high-risk PTCL are poor in adult patients. However, the excellent results in our study suggest that PTCL of childhood is quite different from that of adulthood. Although this study is first report about PTCL of Asian children, the number of patients was small in this study. Larger studies are needed to confirm these findings.

Results for 79 patients with neuroblastoma detected through mass screening at 6 months of age in a single institute.

BACKGROUND: In Japan, mass screening for neuroblastoma has been performed at 6 months of age to improve the prognosis of this condition for more than 20 years. In recent years, most neuroblastomas detected by mass screening were considered to have favorable biological features and sometimes tend to regress spontaneously. METHODS: The authors established non-treated observation criteria in 1997 and criteria for observation of residual tumor after first-line chemotherapy in 1999, and have made an effort to reduce the intensity of medical treatment for neuroblastoma. The authors examined outcomes of 79 patients who were found in the Shizuoka neuroblastoma mass screening at 6 months of age and who received medical treatment or underwent observation in Shizuoka Children's Hospital, Shizuoka, Japan, between December 1981 and December 2004. RESULTS: A total of 77 patients survived but the remaining two patients died from complications of medical treatment. None of the patients died due to progression of neuroblastoma. In the cases, non-treated observation was performed in 17. Of those, 12 patients are now under non-treated observation. Of their tumors, two have disappeared, nine have become smaller and another one has not change in size. Observation of residual tumor after first-line chemotherapy was performed in 15 cases, and three disappeared and the other 12 cases became smaller. Medical treatment-related complications were observed in 20 of 67 patients who received medical treatment, and 18 of the 20 patients were seen before establishing non-treated observation criteria. CONCLUSION: Non-treated observation and observation of residual tumor after first-line chemotherapy were useful to reduce medical treatment-related complications.

Spontaneous regression of metastases including meningeal metastasis after gross resection of primary tumor in an infant with stage 4 neuroblastoma.

Neuroblastoma is the most common extracranial solid tumor in childhood. Spontaneous regression has been well described in infants, especially in those with stage 4S and those with low-stage neuroblastoma detected by screening. However, neuroblastoma presenting with intracranial metastasis is generally considered to need a postoperative chemotherapy. Here, we report a 3-month-old girl with stage 4 neuroblastoma presenting with spontaneous regression of metastatic tumor including meningeal metastasis after gross resection of primary tumor. Further investigation may be required to detect patients of this kind without the need of postoperative chemotherapy regardless of their stage at diagnosis.

HLA-B polymorphism in Japanese HIV-1-infected long-term surviving hemophiliacs.

Approximately 30% of patients with hemophilia in Japan were infected with human immunodeficiency virus (HIV) in early 1980s through contaminated blood products. In 1995, a cohort of HIV-infected, asymptomatic patients with hemophilia was set up for follow-up study. Although the patients met the criteria for long-term non-progressor (LTNP) at the entry to the cohort, some of them later developed lymphopenia during five more years of observation. We collected blood samples from 80 long-term survivors; 42 of them did not require antiviral therapy, but the rest were under treatment. Analysis of HLA-B genotype revealed that carriers of known HIV-resistant alleles such as HLA-B*5701, B*5801, and alleles of B27 antigenic group were not increased in frequency, but that HLA-B*1507 was increased in the cohort (6.25% vs. 1.03%, OR = 6.40, p = 0.039). We also observed the decrease in carriers of HLA-B*5401 (3.75% vs. 14.95%, OR = 0.22, p = 0.016). HLAB* 5401 is a relatively common allele in East Asian populations and belongs to the same B22 antigenic group as B55 and B56 which were reported to associate with rapid progression. Our data indicated that HLA class I is one of the host factors involved in the retardation of HIV disease progression as also reported in the previous studies; however, the alleles associated with this resistance were not the same because of divergent host genetic background.

Neuroblastoma detected by mass screening: the Tumor Board's role in its treatment.

Japan has a nationwide mass-screening program for neuroblastoma in 6-month-old infants. Neuroblastoma can regress spontaneously, and some institutions observe selected cases. We evaluated the management of screened neuroblastoma at our hospital since 1997 when an observation program was introduced. Criteria for the observation program were stage-I, stage-II, or stage-IVs tumors, urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA) levels <40 microg/mg creatinine, tumor <5 cm in diameter, no invasion to the intraspinal canal or great vessels, and parental consent to participate. Patients who did not meet observation criteria underwent surgery or mild chemotherapy according to the location of the tumor. If patients met observation criteria after chemotherapy, surgical intervention was no longer performed. Thirty-six patients attended our hospital for screened neuroblastoma from 1997 to 2002. Thirty-three patients who were managed at our hospital participated in this study. Ten subjects met observation criteria. Tumors regressed in 7 patients (mean follow-up period 36.3 months) with corresponding decreases in VMA and HVA levels (group A). Three underwent surgery (group B) because of increasing VMA and HVA levels, increase in tumor size, or guardian's request. Twenty-three subjects did not meet observation criteria. Four patients underwent primary surgery (group C), and 19 patients had chemotherapy initially. Fourteen patients met observation criteria after chemotherapy and two are still having chemotherapy (group D). Three patients required surgery due to insufficient regression of their tumors (group E). Fourteen subjects in group D had marked decreases in VMA and HVA levels and tumor size (mean follow-up period 29.1 months), and tumors were not detected using imaging techniques in 8 patients. Histological examination of all resected specimens during the study period showed favorable histology and no N-myc amplification. There was no evidence of unfavorable prognosis in any of the 33 subjects, although 1 patient who underwent primary surgery had a vanishing kidney 1 year later and 1 patient had multiple bony metastases after complete resection of tumor, which was treated by chemotherapy. Until the real significance of mass screening for neuroblastoma as a public health measure is confirmed, observation with careful follow-up should be adopted more extensively because it has a favorable outcome in many cases, and is associated with minimal therapeutic complications.

[Continuous infusion of recombinant activated factor VII during and after elbow arthroplasty in a hemophilia A patient with inhibitors].

Recombinant activated factor VII (rFVIIa) is a recently added new agent for the treatment of hemophiliacs with inhibitors. A major drawback to the use of rFVIIa is its short half-life, necessitating frequent and intermittent bolus injections. Continuous infusion of rFVIIa has been reported as a feasible, convenient, safe and cost-effective alternative to intermittent bolus injections. We report the use of continuous rFVIIa infusion during and after left elbow arthroplasty in a hemophiliac with a high titer of inhibitor to factor VIII. rFVIIa was administered as a bolus injection (100 micrograms/kg) at the start of the operation, after which continuous infusion (10-30 micrograms/kg/h) was immediately started and continued for 6 days. Tranexamic acid (50 mg/kg/day, p.o.) was also administered as an antifibrinolytic treatment. Laboratory monitoring of hemostatic efficacy was performed in this case using prothrombin time and the thrombelastogram. Finally, effective intra- and postoperative hemostasis and normal healing of the surgical incisions were achieved, except for local thrombophlebitis. Although the optimal maintenance or target level of rFVIIa has been a matter of debate, we consider continuous infusion of rFVIIa to be a feasible, convenient, safe and cost-effective alternative to intermittent bolus injections.