Picosecond optical vortex converted from multigigahertz self-mode-locked high-order Hermite-Gaussian Nd:GdVO(4) lasers

We report on a gigahertz self-mode-locked high-order Hermite-Gaussian (HG) Nd:GdVO(4) laser. With a pump power of 2.2 W, the average output power for the TEM(0,m) modes from m=9 to m=0 are among 350-780 mW at a repetition rate of 3.5 GHz. The mode-locked pulse width is in the range of 20-25 ps for various HG TEM(0,m) modes. With a simple cylindrical-lens converter, the mode-locked HG beams are converted to generate picosecond optical vortex pulses.

Structure elucidation of three diphenyl ether derivatives from the mangrove endophytic fungus SBE-14 from the South China Sea

Two new natural products, tenelate A (1) and B (2), together with the known compound, tenellic acid C (3), were isolated from the mangrove endophytic fungus Talaromyces sp. (SBE-14), from the South China Sea. Their structures were elucidated by spectroscopic methods, mainly 1D and 2D NMR techniques.

Nonlinear elasticity of stiff biopolymers connected by flexible linkers

Networks of the biopolymer actin, cross-linked by the compliant protein filamin, form soft gels. They can, however, withstand large shear stresses due to their pronounced nonlinear elastic behavior. The nonlinear elasticity can be controlled by varying the number of cross-links per actin filament. We propose and test a model of rigid filaments decorated by multiple flexible linkers that is in quantitative agreement with experiment. This allows us to estimate loads on individual cross-links, which we find to be less than 10 pN.

A virally inactivated functional growth factor preparation from human platelet concentrates

BACKGROUND

Human platelet growth factors (HPGF) are essential for tissue regeneration and may replace fetal bovine serum (FBS) in cell therapy. No method for the manufacture of standardized virally inactivated HPGF has been developed yet.

STUDY DESIGN AND METHODS

Platelet concentrates (PC) were subjected to solvent/detergent (S/D) treatment (1% TnBP/1% Triton X-45), oil extraction, hydrophobic interaction chromatography and sterile filtration. Platelet-derived growth factor (PDGF)-AB, -BB and -AA, transforming growth factor-beta1 (TGF-beta1), epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1) and vascular endothelium growth factor (VEGF) were measured by ELISA. Composition in proteins and lipids was determined, protein profiles were obtained by SDS-PAGE, and TnBP and Triton X-45 were assessed by gas chromatography and high-performance liquid chromatography, respectively. Cell growth promoting activity of HPGF was evaluated by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay using human embryonic kidney (HEK293A) fibroblast and Statens Seruminstitute rabbit corneal (SIRC) epithelial cell lines.

RESULTS

The GF preparation contained a mean of 16.66, 2.04, 1.53, 72.19, 0.33, 48.59 and 0.44 ng/ml of PDGF-AB, -BB, -AA, TGF-beta1, EGF, IGF-1 and VEGF, respectively. The protein profile was typical of platelet releasates and had less than 2 p.p.m. of residual S/D agents. MTS assay of HEK293A and SIRC cultures showed that the GF preparation at 10% and 0.1% (v/v), respectively, could successfully replace 10% FBS for cell proliferation. Cell-stimulating activity of HPGF on HEK293A was over twice that of PC releasates.

CONCLUSION

STANDARDIZED and functional virally inactivated HPGF can be prepared from human PC for possible applications in cell therapy and regenerative medicine.

Observation and analysis of coherent optical waves emitted from large-Fresnel number degenerate cavities

We demonstrate that the coherent optical waves emitted from large-Fresnel-number degenerate cavities persistently display a sort of salient intensity variations. We use the representation of the coherent states to explore the origin of the salient intensity variations and find that these coherent laser waves arise from a quadrature superposition of two degenerate coherent states. With the analytical representation of the superposed coherent states, we verify that these coherent laser waves possess a large angular momentum per photon.

Identification of yeasts and evaluation of their distribution in Taiwanese Kefir and Viili starters

The objective of the present study was to investigate yeast communities in kefir grains and viili starters in Taiwan through conventional microbiological cultivation and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The DNA sequencing was used as a validity technique to ensure that all isolates within each group belonged to just one species, and to confirm the identified results of PCR-DGGE. Results indicated that a combination of conventional microbiological cultivation with PCR-DGGE and sequencing could successfully identify 4 yeast species from both types of cultures in Taiwan. Kluyveromyces marxianus, Saccharomyces turicensis, and Pichia fermentans were found in Taiwanese kefir grains with a distribution of 76, 22, and 2%, respectively, whereas Klu. marxianus, Saccharomyces unisporus and P. fermentans were identified in viili starters corresponding to 58, 11, and 31% of the total cell counts, respectively. Furthermore, the culture-independent method was applied to identify the yeast species using DGGE. Only 2 yeast species, Klu. marxianus and S. turicensis, were found in kefir grains and 2, Klu. marxianus and P. fermentans, in viili starters. These results suggest that in samples containing multiple species, PCR-DGGE may fail to detect some species. Sequences of yeast isolates reported in this study have been deposited in the GenBank database under accession nos. DQ139802, AF398485, DQ377652, and AY007920.

Three-dimensional coherent optical waves localized on trochoidal parametric surfaces

We theoretically demonstrate that the three-dimensional (3D) coherent laser waves formed by the degenerate Laguerre-Gaussian modes with different longitudinal indices are well localized on rotating trochoidal parametric surfaces. We further use a large-Fresnel-number laser system to realize the existence of the laser modes related to trochoidal coherent states. Experimental results reveal that the exotic laser modes generally originate from a superposition of two degenerate standing-wave trochoidal coherent states.

Induction of indoleamine 2,3-dioxygenase in livers following hepatectomy prolongs survival of allogeneic hepatocytes after transplantation

OBJECTIVES

Indoleamine 2,3-dioxygenase (IDO), which catalyzes the breakdown of tryptophan into kyneurenine, has immunologic significance for the induction of maternal tolerance and liver allograft tolerance by inhibiting T-cell activation. In the present study, we compared survival of syngeneic or allogeneic hepatocytes in livers with or without hepatectomy. Subsequently, we investigated gene expression and localization of IDO in the recipient liver.

METHODS

DA and Fisher 344 rats were used in the following experimental groups: group 1, DA hepatocytes transplanted into hepatectomized Fisher 344 rats; group 2, Fisher 344 hepatocytes transplanted into hepatectomized Fisher 344 rats; group 3, DA hepatocytes transplanted into nonhepatectomized Fisher 344 rats; and group 4, Fisher 344 hepatocytes transplanted into nonhepatectomized Fisher 344 rats. After transplantation, the surviving cells were evaluated on day 5. The IDO signal of the recipient liver was detected by reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry.

RESULTS

In the hepatectomized groups subjected to allogeneic or syngeneic hepatocyte transplantation, the number of surviving hepatocytes was greater than in the nonhepatectomized group after transplantation. The IDO signals (RT-PCR) in the hepatectomized groups were stronger than those in the nonhepatectomized groups. Immunohistochemistry demonstrated that the IDO signal is located in liver antigen-presenting cells, such as Kupffer cells or dendritic cells, and not expressed in hepatocytes.

CONCLUSIONS

Our results demonstrated that IDO is induced in antigen-presenting cells of hepatectomized livers by which subsequently transplanted cells may be protected from rejection by inhibiting indirect or direct recognition of donor antigen and further T-cell activation.

Crumpling wires in two dimensions

An energy-minimal simulation is proposed to study the patterns and mechanical properties of elastically crumpled wires in two dimensions. Our aim is to describe the behavior at the intermediate occupancy of the cavity so that its radius of gyration is varied up to one twentieth of the wire length. We tuned the bending rigidity and stretching modulus to measure the energy allocation, size-mass exponent, and the stiffness exponent. The mass exponent is shown to be constant at value D_{M}=1.33 , so is the stiffness exponent alpha=-0.25 . But the latter varies with the plasticity parameters s and theta_{p} . These numerical findings agree excellently with the experimental results.

Crumpling under an ambient pressure

A pressure chamber is designed to study the crumpling process under an ambient force. The compression force and its resulting radius for the ball obey a power law with an exponent that is independent of the thickness and initial size of the sheet. However, the exponent is found to be material dependent and less than the universal value, 0.25, claimed by the previous simulations. The power-law behavior disappears at high pressure when the compressibility drops discontinuously, which is suggestive of a locked state.

3-[(R)-3,3-Dichloro-2-hydroxy-prop-yl]-8-hydr-oxy-6-meth-oxy-1H-isochromen-1-one

The title compound, C₁₃H₁₂Cl₂O₅, is an isocoumarin compound which has been isolated from the ethyl acetate extract of the fermentation broth of actinomycete Streptomyces sp. (V₄) from the South China Sea. There are intra- and inter­molecular hydrogen bonds and halogen bonds [Cl⋯Cl = 3.434 (2) Å; C—Cl⋯Cl = 121.6°]. The intermolecular O—H⋯O hydrogen bonds link mol­ecules into chains along the b axis.

1H and 13C NMR assignments for 6-demethylvermistatin and two penicillide derivatives from the mangrove fungus Guignardia sp. (No. 4382) from the South China Sea

One new compound 6-demethylvermistatin (1), together with two known compounds, the penicillide derivatives (2) and (3) were isolated from the mangrove fungus Guignardia sp. No. 4382 obtained from the South China Sea. Their structures were assigned using high-resolution electron ionization mass spectrometry(HREIMS), (1)H and (13)C NMR spectra, DEPT, and by 2D COSY, HMQC, and HMBC experiments. The absolute configuration of 1 was established by comparison of its CD with that of vermistatin.

A new hTopo I isomerase inhibitor produced by a mangrove endophytic fungus no. 2240

A new hTopo I isomerase inhibitor, (+)-3,3',7,7',8,8'-hexahydroxy-5,5'-dimethylbianthraquinone (2240A), was isolated from the mangrove endophytic fungus no. 2240 collected from an estuarine mangrove at the South China Sea coast. Its structure was elucidated by spectral analyses including two-dimensional NMR, HR-EI-MS, IR, and UV. The hTopo I isomerase inhibition experiment showed that 2240A (1) possessed strong inhibiting activity. When its inhibition concentration was 4.65 micromol/l, its percent inhibition rate was 59.1%, while the lowest inhibition concentration of the positive control camptothecin was 1.00 x 10(3) micromol/l.

Two new metabolites from the mangrove endophytic fungus no. 2106

Two new metabolites, named no. 2106 A (1) and cyclo-(N-MeVal-N-MeAla) (2), have been produced by the endophytic fungus no. 2106 isolated from the seeds of the mangrove Avicennia marina in Hong Kong. The structures were elucidated by 2D NMR, HR-MS, and X-ray diffraction analyses.

[Secondary metabolites of a marine mangrove fungus (Penicillium sp. no. 2556) from South China Sea]

The metabolites of a marine mangrove fungus (Penicillium sp. No. 2556) were studied in this paper and six compounds were isolated from the fermentation liquid. Their structures were elucidated by spectroscopy methods as Sch54796 (1), Sch54794 (2), 4-hydroxybenzoic acid (3), urail (4), succinic acid (5), Vermopyrone (6). Among them, compounds 1, 2 and 6 were firstly isolated from Penicillium sp., Coumpounds 1 and 2 remarkably inhibited the growth of cancer cell lines hep2 and hepG2.

Adrenomedullin enhances baroreceptor reflex response via cAMP/PKA signaling in nucleus tractus solitarii of rats

Adrenomedullin (ADM), a 52-amino acid peptide, elicits differential cardiovascular responses when it is administered systemically or directly to the brain. We evaluated in the present study the hypothesis that ADM may modulate baroreceptor reflex (BRR) response through an ADM receptor-mediated cAMP/ protein kinase A (PKA)-dependent mechanism in the nucleus tractus solitarii (NTS), the terminal site for primary baroreceptor afferents, using Sprague-Dawley rats. Our immunoblot and immunohistochemical results showed that the two component proteins of the ADM(1) receptor complex, calcitonin receptor-like receptor (CRLR) and receptor activity modifying protein (RAMP)-2, were uniformly distributed and highly co-localized in the NTS. Site-specific microinjection of ADM (0.02-0.2pmol) unilaterally into the NTS significantly increased BRR response and sensitivity in a time- and dose-related manner, without affecting arterial pressure and heart rate. The BRR enhancing effect of ADM was also temporally correlated with an up-regulation of PKA(beta), the active form of PKA and an increase in PKA activity. In addition, the ADM-evoked BRR enhancement or PKA activation was abolished by co-microinjection with a selective ADM(1) receptor antagonist, ADM(22-52), an adenylyl cyclase inhibitor, SQ22536, or a PKA inhibitor, Rp-8-bromo-cAMP. These results suggest that ADM enhances BRR via activation of a cAMP/PKA-dependent mechanism by acting site-specifically on ADM(1) receptors in NTS.

[Cytotoxicity of the secondary metabolites of Marine Mangrove Fungus Paecilomyces sp. tree 1-7 on human hepatoma cell line HepG2]

OBJECTIVE

To study the cytotoxicity of the secondary metabolites of Marine Mangrove Fungus Paecilomyces sp. Tree 1-7 on human hepatoma cell line HepG2 cultured in vitro.

METHODS

Three groups were divided: compounds group, 5-Fu group and control group. The cytotoxicity was measured by MTT method when HepG2 cells were treated by different concentration of the secondary metabolites of Paecilomyces sp. Tree 1-7.

RESULTS

Secalonic acid A, tenellic acid A and alternin inhibited the growth of human hepatoma cell line HepG2, the IC50 separately were 2.0, 62.1 and 7.0 microg/ml.

CONCLUSION

Secalonic acid A and alternin have strong cytotoxicity on HepG2 cultured in vitro.

1H and 13C NMR assignments for two lignans from the heartwood of Streblus asper

In our ongoing investigation of the bioactive constituents from plants, two new lignans, magnolignan A-2-O-beta-D-glucopyranoside and strebluslignanol were isolated from heartwood of Streblus asper, along with three known lignans, magnolignan A, magnolol, and magnaldehyde D. 1D and 2D NMR experiments, including COSY, HMQC, and HMBC, and other spectroscopic methods, including UV, IR, and MS were used for the determination of the structures and NMR assignments. Primary bioassays showed that magnolignan A-2-O-beta-D-glucopyranoside and strebluslignanol have medium cytotoxic activity against HEp-2 and HepG2 cells, with IC(50) of 13.3 microM, 46.4 microM and 10.1 microM, 21.7 microM, respectively.

[Secondary metabolites of a marine actinomycete Streptomyces sp. (No. 195-02) from South China Sea]

The metabolites of a marine streptomyces sp. actinomycete (No. 195-02) were studied and eight compounds were isolated from the fermentation liquid, structures were elucidated by spectroscopy methods as p-hydroxy-benzonitrile (1), 2-methyl-furan-3-carboxylic acid(2), furan-2-carboxylic acid (3), cyclo(Phe-Phe) (4), cyclo(Leu-Ileu) (5), nicotinic acid (6), 2-(1H-indol-3-yl) acetic acid (7) and bis(2-ethylhexyl) phthalate (8). The compounds 1, 3 and 8 were firstly isolated from Streptomyces sp., compounds 4 -7 were firstly found from marine actinomycetes. Coumpouds 4 and 5 evidently inhibited the growth of cancer cell lines hepG2 and hep2 at the concentration of 50 microg/ml.

The role of a nuclear protein, histone H1, on signalling pathways for the maturation of dendritic cells

We have demonstrated previously that liver allograft tolerance is associated with the immunosuppressive activity of anti-histone H1 autoreactive antibodies induced in the serum of liver transplantation. Furthermore, we and others have shown that nuclear proteins such as histone H1 and high mobility group box 1 play an important role in maturation of dendritic cells (DCs), although the precise mechanisms are still unknown. In the present study, we focus upon the significance of histone H1 on DCs in terms of the intracellular signalling pathway of DCs. Our immunostaining and immunoblot studies demonstrated that histone H1 was detected in cytoplasm and culture supernatants upon the activation of DCs. Histone H1 blockage by anti-histone H1 antibody down-regulated the intracellular activation of mitogen-activated protein kinases (MAPKs) (p38) and IkappaBalpha of DCs, and inhibited DC activity in the proliferation of CD4+ T cells. On the other hand, the addition of histone H1 without endotoxin stimulation up-regulated major histocompatibility complex class II, the CD80 and CD86 surface markers of DCs and the activation of MAPKs (p38 and extracellular-regulated kinase 1/2) and IkappaBalpha. These results suggest that the translocation of histone H1 from nuclei to cytoplasm and the release of their own histone H1 are necessary for the maturation of DCs and the activation for T lymphocytes.

[Isolation and identification of Suavissimoside R1 from roots of Rubus parvifollus used for protecting dopaminergic neurons against MPP+ toxicity]

OBJECTIVE

Suavissimoside R1 was isolated and identified as an active ingredient from Roots of Rubus parvifollus L, which exhibited protective effect on dopaminergic neurons against MPP+ toxicity.

METHODS

The protective effects of crude extracts were investigated after mice were treated with 1-methyl4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). According to the protective effects of crude extracts, suavissimoside R1, one kind of triterpenoid saponin, was separated. It was investigated that whether Suavissimoside R1 can protect DA neurons from toxicity induced by MPP+ in rat mesencephalic cultures.

RESULTS

Suavissimoside R1 was isolated from Roots of Rubus parvifollus L. Moreover, Suavissimoside R1, in dose of 100 micromol/L, alleviated the death of DA neurons induced by MPP+ obviously.

CONCLUSION

These results suggest that suavissimoside R1 possesses potent neuroprotective activity and can be developed to be a potential anti-Parkinson's disease drug worthy for further study.