Femtosecond mode-locked Nd(3+)-doped Ba(Zr,Mg,Ta)O(3) ceramic laser.

We have demonstrated continuous wave (CW) laser operation and the first, to the best of our knowledge, sub-200 fs mode-locked laser operation of Nd(3+)-doped Ba(Zr,Mg,Ta)O(3) ceramic. Its disordered crystalline nature exhibits a broad gain bandwidth of 30 nm with a high-emission cross section. It also has higher thermal and mechanical properties than Nd:glass. In CW operation, a maximum output power of 1.5 W under 6.2 W of absorbed pump power was obtained. In mode-locked operation, a pulse duration of 196 fs with an average power of 60 mW was successfully achieved. The laser spectrum straddled both fluorescence peaks of A-site and B-site Nd(3+) ions.

Ultrashort pulse generation from diode pumped mode-locked Yb3+:sesquioxide single crystal lasers.

We present diode pumped SESAM supported Kerr-lens mode locked laser operation based on Yb3+:Sc2O3 and Yb3+:Lu2O3 single crystals. Pulses as short as 71 fs with an average power of 1.09 W were obtained from an Yb3+:Lu2O3 single crystal. Yb3+:Sc2O3 delivered pulses as short as 81 fs with an average power of 840 mW. The mode locked laser operation was stable for longer than 2 hours.

167 W, power scalable ytterbium-doped photonic bandgap fiber amplifier at 1178 nm.

An ytterbium-doped photonic bandgap fiber amplifier operating at the long wavelength edge of the ytterbium gain band is investigated for high power amplification. The spectral filtering effect of the photonic bandgap efficiently suppresses amplified spontaneous emission at the conventional ytterbium gain wavelengths and thus enables high power amplification at 1178 nm. A record output power of 167 W, a slope efficiency of 61% and 15 dB saturated gain at 1178 nm have been demonstrated using the ytterbium-doped photonic bandgap fiber.

High-power Yb-doped photonic bandgap fiber amplifier at 1150-1200 nm.

Ytterbium-doped solid-core photonic bandgap fiber amplifiers operating at the long-wavelength edge of the ytterbium gain band are reported. The low-loss bandgap transmission window is formed in the very low gain region, whilst outside the bandgap, large attenuation inhibits the exponential growth of amplified spontaneous emission in the huge-gain 1030-1100 nm region. Hence parasitic-lasing-free, high-power amplification with a marked efficiency is enabled. A 32 W output at 1156 nm with a 66% slope efficiency and 30 W output at 1178 nm with a 58% slope efficiency were successfully obtained. To our knowledge, these are the highest output powers generating from active photonic bandgap fibers, as well as from ytterbium-doped fiber lasers at these wavelengths.

Diode-pumped mode-locked Yb(3+):Lu(2)O(3) ceramic laser.

We report a diode-pumped passively mode-locked Yb(3+):Lu(2)O(3) ceramic laser by use of a semiconductor saturable absorber mirror. Almost transform-limited 357 fs pulses at the center wavelength of 1033.5 nm with a maximum average power of 352 mW are obtained. The efficiency against the absorbed pump power is as high as 32% by use of a laser-diode pumping and the repetition rate is 97 MHz. This is the first demonstration of a diode-pumped mode-locked Yb(3+):Lu(2)O(3) ceramic laser to our knowledge.

Analysis of the immunoglobulin heavy chain gene variable region of CD5-positive and -negative diffuse large B cell lymphoma.

We analyzed nucleotide sequence and intraclonal diversity of the rearranged immunoglobulin heavy chain gene variable region (VH gene) of CD5+ and CD5- diffuse large B cell lymphoma (DLBCL) to clarify the cell origin of de novo CD5+ DLBCL. Ten cases of CD5+ DLBCL and 29 cases of CD5- DLBCL were analyzed. The frequencies of somatic mutation were 0.7 to 12.9% (average, 6.2%) in CD5+ DLBCL and 2.0 to 25.9% (average, 11.1%) in CD5- DLBCL. The ongoing mutation rate was estimated from the number of further single base-substitutions, expressed as a percentage of the total number of nucleotides in 10 cloned PCR products for each case (%). The averages of the ongoing mutation rate of CD5+ DLBCL (four cases) and CD5 DLBCL (seven cases) were 0.051% and 0.197%, respectively. The rate of CD5+ DLBCL was significantly lower than that of CD5- DLBCL (t-test, P = 0.024). These data may indicate that the cell origin of CD5+ DLBCL is different from that of CD5- DLBCL. CD5 is not an activated antigen in DLBCL, but a specific marker of the B1 subset of the B cells, and de novo CD5+ DLBCL may therefore be derived from this unique subset.

Retardation of the age-associated decline of immune functions in aging rats under dietary restriction and daily physical exercise.

Wistar rats were subjected to dietary restriction and daily physical exercise for 21 months, starting from 2 months of age. At the age of 23 months, the rats were sacrificed and examined for various indices including immunological functions. Body weight was almost the same between rats fed ad libitum (Group A) and those (Group B) fed 80% of the diet consumed by Group A. The body weights of Groups A and B were significantly heavier than that of rats (Group C) fed 60% of the diet consumed by Group A and those (Group D) which were subjected to physical exercise and fed 80% of the diet consumed by Group A. Highly proliferative response of T cells to mitogens was observed in 5 out of 13 rats in group D. Some enhancement of B cell proliferation was also observed in the same rats. Present results suggested that enduring physical exercise together with dietary restriction can retard the age-related decrement of immunological functions.

Immunoglobulin heavy chain gene analysis of ocular adnexal extranodal marginal zone B-cell lymphoma.

PURPOSE: To clarify the cellular origin of extranodal marginal-zone B-cell lymphoma (EZML) of the mucosa-associated lymphoid tissue (MALT) type in ocular adnexa, the somatic mutation was analyzed in the immunoglobulin heavy-chain variable region (VH) gene. METHODS: Eight cases of EZML in the orbit and four in the conjunctiva were studied. The VH genes were amplified by a seminested PCR and sequenced directly. These were compared with the closest published VH germline segments to determine the somatic mutation frequency. Intraclonal microheterogeneity, which was termed the ongoing mutation frequency in the current study, was estimated by counting the number of single nucleotide substitutions in individual clones and dividing by the total number of nucleotides analyzed. Nine cases of gastrointestinal EMZL were also examined for comparison. RESULTS: The somatic mutation frequency varied between 2.0% and 12.7%, with a mean value of 7.9%. Ten cases with intraclonal microheterogeneity showed between one and six further substitutions. The average of ongoing mutation frequency was 0.11%, with a range of 0% to 0.25%. In the gastrointestinal EMZLs, the average of somatic mutation frequency was 8.5% (1.5%-14.2%) and of ongoing mutation frequency was 0.51% (0.25%-0.75%). CONCLUSIONS: The average of ongoing mutation frequency in ocular adnexal EMZL was lower than that in gastrointestinal EMZL. Both ocular adnexal and gastrointestinal EMZLs are derived from postgerminal center memory B cells, but the low ongoing mutation frequencies of ocular adnexal EMZL may result from less antigen stimulation and follicular colonization in the orbit relative to gastrointestinal EMZL.

Diode-pumped mode-locked Yb3+:Y2O3 ceramic laser.

A diode-pumped femtosecond ytterbium laser with a host material of Y2O3 ceramics is reported. Passive mode locking by a semiconductor saturable-absorber mirror generates 98-MHz, 615-fs pulses at a center wavelength of 1076.5 nm. The average power is 420 mW and the pulse energy is 4.3 nJ with a 2.6-W absorbed pump power. To our knowledge, this is the first continuous-wave mode-locked ceramic laser.

Aberrant expression of Fra-2 promotes CCR4 expression and cell proliferation in adult T-cell leukemia.

Adult T-cell leukemia (ATL) is a mature CD4+ T-cell malignancy etiologically associated with human T-cell leukemia virus type 1 (HTLV-1). Primary ATL cells frequently express CCR4 at high levels. Since HTLV-1 Tax does not induce CCR4 expression, transcription factor(s) constitutively active in ATL may be responsible for its strong expression. We identified an activator protein-1 (AP-1) site in the CCR4 promoter as the major positive regulatory element in ATL cells. Among the AP-1 family members, Fra-2, JunB and JunD are highly expressed in fresh primary ATL cells. Consistently, the Fra-2/JunB and Fra-2/JunD heterodimers strongly activated the CCR4 promoter in Jurkat cells. Furthermore, Fra-2 small interfering RNA (siRNA) or JunD siRNA, but not JunB siRNA, effectively reduced CCR4 expression and cell growth in ATL cells. Conversely, Fra-2 or JunD overexpression promoted cell growth in Jurkat cells. We identified 49 genes, including c-Myb, BCL-6 and MDM2, which were downregulated by Fra-2 siRNA in ATL cells. c-Myb, BCL-6 and MDM2 were also downregulated by JunD siRNA. As Fra-2, these proto-oncogenes were highly expressed in primary ATL cells but not in normal CD4+ T cells. Collectively, aberrantly expressed Fra-2 in association with JunD may play a major role in CCR4 expression and oncogenesis in ATL.

784-nm amplified spontaneous emission from Tm3+-doped fluoride glass fiber pumped by an 1120-nm fiber laser.

We report 784-nm (1G4 --> 3H5 transition) amplified spontaneous emission (ASE) from Tm3+-doped fluoride (ZrF4-BaF2-LaF3-AlF3-NaF) glass fiber pumped by an 1120-nm fiber laser. To our best knowledge, this is the first report of 784-nm (1G4 --> 3H5 transition) ASE in a Tm3+-doped fluoride fiber laser. Its effects on a 480-nm (1G4 --> 3H6 transition) blue laser were also discussed.

Pulse-front-matched optical parametric amplification for sub-10-fs pulse generation tunable in the visible and near infrared.

A noncollinear optical parametric amplifier is presented that generates transform-limited sub-10-fs pulses that are tunable in both the visible and the near infrared (NIR). The pulse-front-matched pump geometry realizes tilt-free signal amplification, and pulses as short as 6.1 fs can be obtained from 550 to 700 nm. The large angular dispersion of the idler specific to the group-velocity-matching interaction is effectively eliminated by a grating-telescope compensator, and 9-fs NIR pulses are also successfully obtained from 900 to 1300 nm. This is believed to be the first tunable sub-10-fs light source.

Spatial-phase code-division multiple-access system with multiplexed Fourier holography switching for reconfigurable optical interconnection.

A new, to our knowledge, space-variant optical interconnection system based on a spatial-phase code-division multiple-access technique with multiplexed Fourier holography is described. In this technique a signal beam is spread over wide spatial frequencies by an M-sequence pseudorandom phase code. At a receiver side a selected signal beam is properly decoded, and at the same time its spatial pattern is shaped with a Fourier hologram, which is recorded by light that is encoded with the same M-sequence phase mask as the desired signal beam and by light whose spatial beam pattern is shaped to a signal routing pattern. Using the multiplexed holography, we can simultaneously route multisignal flows into individually specified receiver elements. The routing pattern can also be varied by means of switching the encoding phase code or replacing the hologram. We demonstrated a proof-of-principle experiment with a doubly multiplexed hologram that enables simultaneous routing of two signal beams. Using a numerical model, we showed that the proposed scheme can manage more than 250 routing patterns for one signal flow with one multiplexed hologram at a signal-to-noise ratio of ~5.

LEC induces chemotaxis and adhesion by interacting with CCR1 and CCR8.

Liver-expressed chemokine (LEC) is an unusually large CC chemokine, which is also known as LMC, HCC-4, NCC-4, and CCL16. Previously, LEC was shown to induce leukocyte migration but the responsible signaling receptors were not characterized. We report chemotaxis and competitive binding studies that show LEC binds to and activates CCR1 and CCR8 transfected HEK-293 cells. LEC induced maximal migration of CCR1 and CCR8 transfected cells at 89.3 nmol/L and cell adhesion at 5.6 nmol/L. The molar concentration of LEC required to induce maximum cell migration is 20- to 200-fold greater than that required for RANTES or I309, respectively. All 3 chemokines induced maximal static adhesion at 5 to 7 nmol/L. A neutralizing polyclonal antibody to LEC was developed to demonstrate that the unusually high concentration of LEC required to induce chemotaxis was a property of LEC and not as a result of an irrelevant protein contamination. This study suggests that LEC may be a more effective inducer of cell adhesion than cell migration.

Lytic infection of Epstein-Barr virus (EBV) in hemophagocytic syndrome associated with EBV-induced lymphoproliferative disorder.

This report describes lytic infection with Epstein-Barr virus (EBV) in three cases of hemophagocytic syndrome (HPS) presumably associated with EBV-induced lymphoproliferative disorder. All cases were previously healthy females with ages ranging from 52 to 87 years who showed a fulminant clinical course with accompanying fever, liver dysfunction, and disseminated intravascular coagulation. Cases 1 and 2 showed proliferation of atypical T lymphocytes, and case 3 showed proliferation of atypical B lymphocytes. Hemophagocytic histiocytes were observed in the bone marrow, lymph nodes, spleen, and liver. Atypical lymphocytes in all cases showed a positive reaction for both EBV-encoded small RNA (EBER) indicating latent infection with EBV and immediate early mRNAs of the Bam HI fragment of lower stranded frame (BHLF), indicating lytic infection by in situ hybridization. Interestingly, BHLF-positive cells were predominant in all cases. It is possible that reactivation of EBV infection may be involved in triggering the induction of cytokines and abnormal activation of histiocytes.

Analysis of the immunoglobulin heavy chain gene of secondary diffuse large B-cell lymphoma that subsequently developed in four cases with B-cell chronic lymphocytic leukemia or lymphoplasmacytoid lymphoma (Richter syndrome).

The immunoglobulin heavy chain gene (IgH gene) was analysed in four cases of B-cell Richter syndrome, in order to determine whether a secondary diffuse large B-cell lymphoma (DLBCL) could arise from the same clone as the initial B-cell chronic lymphocytic leukemia (B-CLL) and lymphoplasmacytoid lymphoma (LPL) or be a de novo event, and whether secondary DLBCL shows an intraclonal microheterogeneity. Both the initial B-CLL and secondary DLBCL in two cases expressed CD5 antigen. Both samples of the initial B-CLL or LPL and the secondary DLBCL in three cases were examined for comparison. The polymerase chain reaction-amplified IgH gene of secondary DLBCL in two cases (CD5+ case and CD5- case) were different from those of the initial B-CLL, revealing a new malignant clone. The other case (CD5-) showed that secondary DLBCL had a sequence identical to the initial LPL, indicating the same clonal origin. The variable region of the IgH gene of secondary DLBCL (CD5+ two cases and CD5- two cases) exhibited a 0.5-9.0% somatic mutation range and no intraclonal microheterogeneity.