Sub-pm linewidth, high pulse energy, high beam quality microsecond-pulse Ti:sapphire laser at 766.699†nm.

In this letter, a sub-pm linewidth, high pulse energy and high beam quality microsecond-pulse 766.699 nm Ti:sapphire laser pumped by a frequency-doubled Nd:YAG laser is demonstrated. At an incident pump energy of 824 mJ, the maximum output energy of 132.5 mJ at 766.699 nm with linewidth of 0.66 pm and a pulse width of 100 µs is achieved at a repetition rate of 5 Hz. To the best of our knowledge, this is the highest pulse energy at 766.699 nm with pulse width of hundred micro-seconds for a Ti:sapphire laser. The beam quality factor M2 is measured to be 1.21. It could be precisely tuned from 766.623 to 766.755 nm with a tuning resolution of 0.8 pm. The wavelength stability is measured to be less than ±0.7 pm over 30 min. The sub-pm linewidth, high pulse energy and high beam quality Ti:sapphire laser at 766.699 nm can be used to create a polychromatic laser guide star together with a home-made 589 nm laser in the mesospheric sodium and potassium layer for the tip-tilt correction resulting in the near-diffraction limited imagery on a large telescope.

Co-MOFs as Emerging Pulse Modulators for Femtosecond Ultrafast Fiber Laser.

The metal organic framework (MOF) has attracted more and more attention due to its unique morphology, functional linkers, and orderly network structure. Zeolitio imidazolata frameworks (ZIFs), which are formed by bivalent transition metals (Zn, Co, etc.) and nitrogen-containing heterocyclic imidazole or purine organic ligands, are a very attractive subclass of MOFs. ZIF-67, obtained by the nucleation growth of dimethylimidazole and Co 2p, has been developed as a precursor for porous nanostructured cobalt-based metal oxides. During material preparation we add rGO because it can be used as a basic element to construct macroscopic three-dimensional carbon structural materials, which self-assemble into a 3D network structure with ZIF-67 through simple van der Waals forces or hydrogen bonds, and some samples contain specific functional groups that are added to the precursor. In this paper, we employ liquid-phase synthesis to generate rGO-ZIF-67 and calcine it at the temperature of 350 °C to obtain rGO-Co3O4. Then we fabricate rGO-Co3O4 and rGO-ZIF-67 modulators based on microfibers and test their nonlinear optical absorption in 1.5 µm range. The modulation depths of rGO-Co3O4 and rGO-ZIF-67 are measured as 10.41% and 6.61%, respectively. By using microfiber-based rGO-Co3O4 modulator, we have obtained a conventional soliton and a soliton molecule in Er3+-doped fiber lasers. The conventional soliton has a pulse width of 793.4 fs and a spectral width of 3.3 at 1558.9 nm, respectively. The obtained soliton molecule has a spectral modulation period of 1.65 nm and temporal separation of 4.94 ps at 1563.2 nm. By employing a microfiber-based rGO-ZIF-67 modulator, we obtain conventional solitons with a spectral width of 1.9 nm at the central wavelength of 1529.8 nm. Our research may expand the MOF-based materials for ultrafast photonics, blazing a new path for fiber laser, optical communications, and optoelectronics, etc.

Interaction with CD68 and Regulation of GAS6 Expression by Endosialin in Fibroblasts Drives Recruitment and Polarization of Macrophages in Hepatocellular Carcinoma.

Fibroblasts and macrophages play key roles in the development of hepatocellular carcinoma (HCC). However, cross-talk between these two kinds of cells has not been well studied. Endosialin (CD248/TEM1) is a transmembrane glycoprotein that is expressed in certain cancer cells, tumor stromal cells, and pericytes. In this study, we found that endosialin is mainly expressed in cancer-associated fibroblasts (CAF) in HCC and its expression inversely correlates with patient prognosis. Endosialin interacted with CD68 to recruit macrophages and regulated expression of GAS6 in CAFs to mediate M2 polarization of macrophages. The fully human antibody IgG78 bound glycosylated endosialin and induced its internalization in CAFs, thus weakening the cross-talk between CAFs and macrophages. In subcutaneous and orthotopic xenograft models of HCC in nude mice, treatment with IgG78 significantly inhibited tumor growth. These results indicate that endosialin-positive CAFs promote HCC progression and highlight IgG78 as a promising therapeutic candidate for HCC treatment. SIGNIFICANCE: These findings highlight CAF-expressed endosialin as a primary regulator of macrophage recruitment and polarization and demonstrate endosialin inhibition as a potential treatment strategy for HCC. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/18/3892/F1.large.jpg.

A Novel Fully Human Antibody targeting Extracellular Domain of PSMA Inhibits Tumor Growth in Prostate Cancer.

Prostate cancer is the most commonly diagnosed malignancy in men and the second leading cause of cancer-related death. It is of vital importance to develop new strategies for prostate cancer therapy. PSMA (prostate-specific membrane antigen) is specifically expressed in prostate cancer and the neovasculature of certain cancer types, thus is considered to be an ideal target for cancer therapy. In our previous study, we have obtained a PSMA-specific single-chain variable fragment (scFv), named gy1, from a large yeast display naïve human scFv library. In this study, we reconstructed the PSMA scFv into a fully human antibody (named PSMAb) and evaluated its characterization both in vitro and in vivo We showed that PSMAb can specifically bind with and internalize into PSMA+ cells. The binding affinity of PSMAb is measured to be at nanomolar level, and PSMAb has very good thermostability. In vivo study showed that near IR dye-labeled PSMAb can specifically localize at PSMA+ tumors, and the application of PSMAb in vivo significantly inhibited the growth of PSMA+ tumors, but not PSMA- tumors. At the studied doses, no obvious toxicity was observed when applied in vivo, as shown by the relative normal liver and kidney function and normal structure of important organs, shown by hematoxylin and eosin staining. In addition, PSMAb may inhibit tumor growth through antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity mechanisms. Our results indicated that the novel fully human antibody, PSMAb, deserve further study for PSMA-targeted diagnosis and therapy for prostate cancer and other cancer types with vascular PSMA expression.

A novel anti-PSMA human scFv has the potential to be used as a diagnostic tool in prostate cancer.

Prostate cancer (PCa) is the most commonly diagnosed malignancy and the second leading cause of cancer related death in men. The early diagnosis and treatment of PCa are still challenging due to the lack of efficient tumor targeting agents in traditional managements. Prostate specific membrane antigen (PSMA) is highly expressed in PCa, while only has limited expression in other organs, providing an ideal target for the diagnosis and therapy of PCa. The antibody library technique has opened the avenue for the discovery of novel antibodies to be used in the diagnosis and therapy of cancer. In this paper, by screening a large yeast display naive human single chain antibody fragment (scFv) library, we obtained a high affinity scFv targeting PSMA, called gy1. The gy1 scFv was expressed in E.coli and purified via a C terminal 6His tag. The binding affinity of gy1 was shown to be at the nanomolar level and gy1 can specifically bind with PSMA positive cancer cells, and binding triggers its rapid internalization through the endosome-lysosome pathway. The specific targeting of gy1 to PSMA positive tumor tissues was also evaluated in vivo. We showed that the IRDye800CW labeled gy1 can efficiently target and specifically distribute in PSMA positive tumor tissues after being injected into xenograft nude mice. This study indicated that the novel antibody gy1 could be used as a great tool for the development of PSMA targeted imaging and therapy agents for PCa.

Calebin-A induces apoptosis and modulates MAPK family activity in drug resistant human gastric cancer cells.

This study is the first to investigate Calebin-A, a natural compound present in Curcuma longa, which inhibits cell growth and induce apoptosis in SGC7901/VINCRISTINE cells, a multidrug resistant (MDR) human gastric adenocarcinoma cell line. Our data suggest the drug efflux function of P-glycoprotein was inhibited by Calebin-A treatment, while the expression level of P-glycoprotein was not affected. Additionally, co-treatment of Calebin-A and vincristine resulted in a remarkable reduction in S phase and G2/M phase arrest in SGC7901/VINCRISTINE cells. Calebin-A was also found to modulate the activities of mitogen-activated protein kinase (MAPK) family members, which includes decreased c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and increased protein kinase of 38 kDa (p38) activity. These results suggest that Calebin-A might be an effective compound for the treatment of human gastric and other MDR cancers.

A novel technique for efficient construction of large scFv libraries.

The development of patient-tailored anti-tumor therapies requires large-scale production of antibodies for the purpose of screening specific tumor antibodies. Thus, the generation of a single chain fragment of variable region (scFv) library with a large repertoire is required for the selection of specific antibodies with high affinity. Presently, the generation of large scFv libraries is impeded by the low efficiency of cloning PCR fragments into phage display vectors, which is due to the low efficiency of the restriction digestion step required in the process. The aim of this study was to increase the efficiency of this critical step. We found methods that are formally believed to facilitate the digestion efficiency, such as adding longer tails to the primers or prolonging the incubation time, were inefficient. We then investigated the feasibility of using T/A cloning to improve the efficiency of cloning and found that when PCR fragments were first cloned into T-vector, and then subsequently subcloned into a phagemid, the cloning efficiency was dramatically increased. Our findings show that by utilizing this method the construction of a large scFv library can be easily accomplished.

Isolation and identification of an scFv antibody against nucleocapsid protein of SARS-CoV.

To develop reagents for early diagnosis and therapeutic drugs against SARS-associated coronavirus (SARS-CoV), a large (3 x 10(9)) immunized human antibody library was constructed from peripheral blood mononuclear cells from six SARS convalescent patients. A single chain variable fragment antibody (N18) with high affinity against N protein of SARS-CoV was isolated. Sequence analysis revealed that the VL gene was composed of VL3h (V lambda subgroup) and JL2 regions and the VH gene was composed of VH1-69 (VH1 subgroup), D2-15, D3-22 and JH6 regions. Soluble N18 antibody was expressed in Escherichia coli HB2151, purified by Ni-NTA affinity chromatography and verified by SDS-PAGE and Western blot. The potential application for early diagnosis was evaluated using N protein capture ELISA in which N18 antibody demonstrated high sensitive activity in detecting N protein of SARS-CoV. Finally, the potential usefulness of the N18 antibody in prophylaxis, vaccine design and therapy of SARS is discussed.

High expression of bcl-x(L) in K562 cells and its role in the low sensitivity of K562 to realgar-induced apoptosis.

Arsenic compounds (As(2)O(3 )or()As(4)S(4)) have been used successfully for the treatment of acute promyelocytic leukemia (APL) for quite a long time. It has been noticed that the sensitivity to apoptosis induced by As(2)O(3 )varies among various leukemia cells. It was reported by several groups that As(2)O(3) could induce apoptosis in APL-derived NB4 cells at concentrations of 0.5-1 mumol/l, whereas in other leukemia cells like K562, As(2)O(3) has no effects at the same concentration. K562 cells undergo apoptosis only when the concentration of As(2)O(3 )is greater than 2 mumol/l. Another arsenic compound, realgar (As(4)S(4)), a traditional Chinese mineral medicine, has been used to treat APL effectively and demonstrated to have lower toxicity than As(2)O(3). It would be interesting to know whether NB4 and K562 cells will show different sensitivity to realgar as well and if there is a difference, what is the cellular mechanism of it. In our present study, K562 cells were much less sensitive than NB4 cells to apoptosis induced by realgar. We confirm that the expression of bcl-x(L) is significantly higher in K562 cells than that in NB4 cells and is not downregulated upon realgar treatment. K562 cells become sensitive to realgar at clinically acceptable concentrations when bcl-x(L) expression level is downregulated by transfecting bcl-x(L) antisense RNA vector into the cells. Our results suggest that the increased bcl-x(L) expression in K562 cells contributes to its insensitivity to realgar-induced apoptosis.

Construction and significance of directional expression cDNA library from human NB4 cells.

Human acute premyeloid leukemia cell cDNA expression library was constructed to screen acute premyeloid leukemia tumor antigen. Total RNA and purified mRNA were extracted from human premyeloid cell line NB4. First and second strands of cDNA were synthesized by reverse transcription. After blunting, the cDNA fragments were ligated with EcoR I adapters. Then the cDNAs were digested with Xho I, and less than 400 bp cDNA fragment was removed by Sephacryl-S400 spin column, the remaining were ligated with lambdaZAP vector. The recombinants were packaged in vitro, and a small portion of packaged phage was used to infect E. coli XL1-Blue-MRF' for titration. The recombinants were examined by color selection. In order to evaluate the size of cDNA inserts and the diversity of library, the pBK-CMV phagemid was excised from the ZAP express vector by using ExAssist helper phage with XLOLR strain, and then the pBK-CMV phagemid was digested by Xho I and EcoR I. The results showed that the NB4 cell line cDNA library consisting of 1.65 x 10(6) recombinant bacteriophages was constructed with the recombinant ratio of 99.6%. The average length of the recombinant exogenous inserts was about 1.7 kb. It was concluded that the constructed cDNA library are deserved to screen target clones.

[Construction and significance of directional expression cDNA library from myeloid leukemia cell line U937].

To construct the cDNA expression library from human U937 cell, total RNA and purified mRNA in myeloid leukemia cell line U937 were extracted. The first and second strand of cDNA were synthesized through reverse transcription. After blunting the cDNA termini, the cDNA fragments were connected with EcoR I adapters, and the end of EcoR I adapters was phosphorylated. Then the cDNAs were digested by Xho I, and the fragments smaller than 400 bp were removed by Sephacryl-S400 spin column, the fragments longer than 400 bp were ligated with lambdaZAP vector. The recombinants were packaged in vitro, and a small portion of packaged phage was used to infect E coli XL1-Blue-MRF' for titration. The recombinants were examined by color selection. In order to evaluate the size of cDNA inserts and the diversity of library, the pBK-CMV phagemid was excised from the ZAP expression vector by using ExAssist helper phage with XLOLR strain, and then the pBK-CMV phagemid was digested by Xho I and EcoR I. The results showed that the U937 cell line cDNA library consisting of 2.87 x 10(6) recombinant bacteriophages was constructed. The average size of exogenous insert in the recombinants was about 1.7 kb. It is concluded that the constructed cDNA library can be used to screen target clones.