Mixed-valence cytoplasmic iron granules are linked to anaerobic respiration

Intracellular granules containing ferric and ferrous iron formed in Shewanella putrefaciens CN32 during dissimilatory reduction of solid-phase ferric iron. It is the first in situ detection at high resolution (150 nm) of a mixed-valence metal particle residing within a prokaryotic cell. The relationship of the internal particles to Fe(III) reduction may indicate a respiratory role.

Shear modulus and plasticity of a driven charge density wave

We have probed the effects of transverse variations in pinning strength on charge-density-wave (CDW) structure in NbSe3 by x-ray micro-beam diffraction. In ribbonlike crystals having a large longitudinal step in thickness, the CDW first depins on the thick side of the step, causing rotations of the CDW wave vector. By measuring these rotations as a function of position and electric field, the corresponding shear strains are determined, allowing the CDW's shear modulus to be estimated. These results demonstrate the usefulness of x-ray microdiffraction as a tool in studying collective dynamics in electronic crystals.

An X-ray nanodiffraction technique for structural characterization of individual nanomaterials

An X-ray micro/nanodiffraction technique that allows structural characterization of individual nanomaterials has been developed at an insertion-device beamline of the Advanced Photon Source. Using the extremely high brightness of the third-generation synchrotron radiation source and advanced high-resolution high-energy zone-plate focusing optics, X-rays of energies from 6 to 12 keV have been focused into a spot smaller than 200 nm with a photon density gain of more than 50,000 so that significant photon flux can be intercepted by a nanoscale material to generate a measurable diffraction signal for structural characterization. This paper describes the instrumentation of the technique and discusses the application of the technique to studies of tin oxide nanobelts.

Diffraction and imaging study of imperfections of crystallized lysozyme with coherent X-rays

Phase-contrast X-ray diffraction imaging and high-angular-resolution diffraction combined with phase-contrast radiographic imaging were employed to characterize defects and perfection of a uniformly grown tetragonal lysozyme crystal in the symmetric Laue case. The full-width at half-maximum (FWHM) of a 4 4 0 rocking curve measured from the original crystal was approximately 16.7 arcsec and imperfections including line defects, inclusions and other microdefects were observed in the diffraction images of the crystal. The observed line defects carry distinct dislocation features running approximately along the <1 1 0> growth front and have been found to originate mostly in a central growth area and occasionally in outer growth regions. Inclusions of impurities or formations of foreign particles in the central growth region are resolved in the images with high sensitivity to defects. Slow dehydration led to the broadening of a fairly symmetric 4 4 0 rocking curve by a factor of approximately 2.6, which was primarily attributed to the dehydration-induced microscopic effects that are clearly shown in X-ray diffraction images. The details of the observed defects and the significant change in the revealed microstructures with drying provide insight into the nature of imperfections, nucleation and growth, and the properties of protein crystals.

Measurement of the spatial coherence function of undulator radiation using a phase mask

A measurement of the horizontal coherence function of 7.9 keV radiation from an undulator beam line at the Advanced Photon Source is reported. X-ray diffraction from a phase-shifting mask was used, and the coherence function was measured as a function of the width of beam-conditioning slits in the beam line. The coherence distribution is found to be best described by a Lorentzian function.

Observation of columnar microstructure in step-graded Si1-xGex/Si films using high-resolution X-ray microdiffraction

Columnar microstructure in step-graded Si(1-x)Ge(x)/Si(001) structures with low threading dislocation densities has been determined using high angular resolution (approximately 0.005 degrees ) x-ray microdiffraction. X-ray rocking curves of a 3-microm-thick strain-relaxed Si(0.83)Ge(0.17) film show many sharp peaks and can be simulated with a model having a set of Gaussians having narrow angular widths (0.013 degrees -0.02 degrees ) and local ranges of tilt angles varying from 0.05 degrees to 0.2 degrees. These peaks correspond to individual tilted rectangular columnar micrograins having similar (001) lattice spacings and average areas of 0.8 to 2.0 microm(2).

X-ray microdiffraction images of antiferromagnetic domain evolution in chromium

Magnetic x-ray diffraction combined with x-ray focusing optics was used to image individual antiferromagnetic spin density wave domains in a chromium single crystal at the micron scale. The cross section for nonresonant magnetic x-ray scattering depends on the antiferromagnetic modulation vector and spin polarization direction and allows these quantities to be extracted independently. The technique was used to show that the broadening of the nominally first-order "spin-flip" transition at 123 kelvin, at which the spins rotate by 90 degrees C, originates at the walls between domains with orthogonal modulation vectors. During cooling, the transition begins at these walls and progresses inward. The modulation vector domains are themselves unchanged.

[Clinical research on the antitumor activity and phenotype of tumor infiltrating lymphocytes for treatment of lung cancer]

BACKGROUND

To evaluate the feasibility and toxicity of the infusion of tumor infiltrating lymphocytes ( TIL) with rIL-2 in patients with lung cancer.

METHODS

TILs derived from tissue samples which obtained from the surgically removed tumors of 51 patients were cultivated in vitro. Fifteen patients were infused with 0. 2×10⁸ to 1. 62×10⁸ TIL cells intravenously at 2-8 weeks after operation and rIL-2 was inhaled into lung at dose of 3×10⁵ U/ day for 3 days. TIL cytolytic activities on day 0 and day 25th after incubation were assessed with 3H-TdR release assay in vitro while the positive proportion of phenotypes of TIL were estimated with indirect immunofluorescence technique.

RESULTS

The cytolytic activity of TIL against autologous tumor cell and 801-D cell line after incubation ( 50. 35% and 42. 81% respectively) was significantly higher than that before incubation ( 13. 01% and 11. 46% respectively) ( P < 0. 05) . There was no apparent difference of the cytolytic activity between autologous tumor cell group and 801-D cell line group. The percentage of CD3+ and CD8+ TILs after culture was significant higher than that before cultivation( P < 0. 05) and there was no change in the percentage of CD4+ TILs and the ratio of CD4+ / CD8+ . Adverse effects were mild, only 3 of 15 patients had fever, headache, and nausea immediately after infusion of TIL and then recovered within several hours. Others had no any side effects. The immunity function of all patients was improved after infusion.

CONCLUSIONS

The result suggests that the infusion of expanded TILs in vitro, derived from surgical samples, is feasible and safe in patients with locally advanced lung cancer.

Phase sensitive x-ray diffraction imaging of defects in biological macromolecular crystals

Conventional x-ray diffraction topography is currently used to map defects in the bulk of protein crystals, but the lack of sufficient contrast is frequently a limiting factor. We experimentally demonstrate that this barrier can be circumvented using a method that combines phase sensitive and diffraction imaging principles. Details of defects revealed in tetragonal lysozyme and cubic ferritin crystals are presented and discussed. The approach enabling the detection of the phase changes of diffracted x rays should prove to be useful in the study of defect structures in a broad range of biological macromolecular crystals.

The influence of human single chain inteleukin-12 gene transduction on the biological behavior of hepatoma 7721 cells

OBJECTIVE

To investigate the anti-tumor effects of human single chain interleukin-12 (hscIL-12).

METHOD

pcDNA/hscIL-12 recombinant was transfected into human hepatic carcinoma cells (7721 cells) by lipofectin method. The 7721/hscIL-12 cells which secrete hscIL-12 stably, were obtained via G418 selection, and in vitro the influence of hscIL-12 gene transduction on the growth of tumor cells was evaluated by cell cycle analysis. In vivo, genetically engineered 7721 cells (7721/hscIL-12, 7721/pcDNA) and parental cells were implanted into BALB/c nude mice, respectively. 7721/pcDNA and 7721/hscIL-12 groups were divided into two sub-groups on day 8: one was administered with hPBL twice, 6 days at interval; the other was given equal volume of PBS. Mice were sacrificed on day 26, and spleens and tumors were taken out for histologic assay.

RESULTS

hscIL-12 produced stably by 7721/hscIL-12 cells had bioactivity, and it was proved by Western blot, immunocytochemistry, and in situ hybridization. In vitro, compared with 7721 and 7721/pcDNA, the 7721/hscIL-12 grew much more slowly. FACS assay showed apparent G1 arrest of 7721/hscIL-12 cells. In animal experiment, on day 8 after inoculation, the tumors of 7721 and 7721/pcDNA group were up to 5 approximately 7 mm, while those of 7721/hscIL-12 group were 2 approximately 4 mm. When treated with hPBL, the tumor of 7721/hscIL-12 group disappeared completely. Histologically, the tumors from 7721/hscIL-12 without hPBL treatment had numerous lymphocyte infiltration, the tumor cells displayed depression looking, atrophy, focal necrosis and apoptosis, whereas the tumors of 7721 and 7721/pcDNA groups grew thrivingly.

CONCLUSION

hscIL-12 transduced 7721 cells could induced significant antitumor immune response which resulted in tumor regression totally when the hPBL was inoculated, and also hscIL-12 has certain effects on mice immune system. These findings suggest that hscIL-12 and hscIL-12 gene therapy might have promising prospects in clinical application.

[Inhibitory effect of 5F11-DXR immunoconjugate on human lung cancer cells]

BACKGROUND

To evaluate the inhibition effect of immunoconjugate of doxorubicin(DXR) with a monoclonal antibody, 5F11 on human lung cancer cells and its reversal effect on resistant lung cancer cells to chemotherapeutic drug.

METHODS

DXR was attached to 5F11 using dilute glutaraldehyde crossing.The antitumor activity of immunoconjugate, 5F11-DXR, against the sensitive antigen-positive cell line, A2, drug-resistant antigen-positive cell lines, 801-D and 801-DDXR, and antigen-negative cell line, ascite cancer cell was evaluated by human tumor cell cloning assay and dye exclusion assay.

RESULTS

According to the results of various assays, comparing with single DXR, 5F11-DXR could significantly increase the cytotoxicity to A2, 801-D and 801-DDXR cell lines with a DXR concentration of 0.4 μg/ml(P<0.05), and this difference was even more distinct to A2 cell line with lower concentration of DXR (0.04 μg/ml). However, there was no remarkable difference between 5F11-DXR and single DXR in cytotoxicity to antigen-negative ascite cancer cell(P>0.05).

CONCLUSIONS

5F11-DXR can remarkably increase the cytotoxicity of DXR to the sensitive target cells and even effectively reverse the drug-resistant cell lines to DXR. There is no significant difference between 5F11-DXR and DXR in killing antigen-negative cancer cells.

[Frequent loss of heterozygosity on chromosome 4 in human hepatocellular carcinoma]

OBJECTIVE

Few previous studies have shown high frequency of loss of heterozygosity (LOH) on chromosome 4q in hepatocellular carcinoma (HCC). We define more clearly the deletion regions that may harbor the putative tumor suppressor genes in HCC.

METHODS

Forty-eight cases of HCC and their corresponding non-tumor liver tissues were investigated with 12 microsatellite polymorphic markers for LOH.

RESULTS

Twenty-one of 48 (44%) and 30 of 48 (63%) tumors showed LOH on at least one locus on the short and the long arms respectively. Two distinct common deleted regions (CDR) with different patterns of deletion were identified. The first CDR was located on 4q22-q25, between loci D4S392 and D4S1625. In addition, 17 of 27 (63%) of the informative tumors showed LOH on this region with locus D4S406 and constituted the highest rate of LOH on chromosome 4. The second CDR was located at 4q27-q31, between loci D4S1625 and D4S1652.

CONCLUSION

There are at least two tumor suppressor loci on 4q.

[Killing effect of low intensity ultrasound on human lung cancer cells in vitro]

BACKGROUND

To investigate the effects of low intensity ultrasound on human lung cancer cells.

METHODS

The human small cell lung cancer cells line SM, adenocarcinoma cell line A2 and human lung fibroblast cells FB were treated with low intensity ultrasound, and the killing effects of ultrasound on the cells were detected by the trypan blue exclusion and clonogenic survival assay.

RESULTS

The killing effects of low intensity ultrasound ( 0. 8W/ cm²) on various type of human lung cancer and human pulmonary fibroblast were observed after 3-minute treatment. All of the cells were killed by sonicate for 10-minute treatment. The higher the cell concentration, the lower the killing efficiency. The temperature in the tube containing cell suspension did not obviously increase after 10-minute sonicate. Compared with the application of doxorubicin alone, the doxorubicin cytoxicity was increased by 100-fold in SM cell cologenic survival assay when doxorubicin was combined with an intensity of ultrasound at 0. 8W/ cm².

CONCLUSIONS

The low intensity continuous wave ultrasound can obviously kill lung cancer cells and dramatically increase the cytotoxicity of doxorubicin for lung cancer cells.

[Experimental research of tumor infiltrating lymphocytes for treatment of lung cancer]

BACKGROUND

To explore the conditions and characterization of tumor infiltrating lymphocytes(TILs) isolation and expansion.

METHODS

TILs were separated from tissue samples which obtained from the surgically removed tumor of 67 patients with lung cancer bymechanic and enzyme digestion and discontinuous density Ficoll-paque gradient centrifugation ways. TILs from 34 patients were incubated with 10% human type AB serum RPMI-1640 in vitro.

RESULTS

The average number of TIL was 6. 84*10⁶ per gram tumor tissue. The number of TIL from patients in stage I was greater than that from patients in stage III and IV , but with no difference in expanding among them. The number of TIL from patients with adenocarcinoma was similar to that with squamous cell carcinoma, but TIL isolated from adenocarcinoma expanded much more faster than that from squamous cell carcinoma. TIL expanded rapidly during 7-28 days and most of them appeared the maximum expansion within 35 days. TIL incubated from 17 of 34 patients had expanded exceeding 1*10⁹, so the rate of infusion was 50%.

CONCLUSIONS

The results suggest TIL can be effectively separated from the tumor and expanded in vitro and these provide the basis for adoptive immunotherapy with TIL in the treatment of lung cancer.

Formation of sphalerite (ZnS) deposits in natural biofilms of sulfate-reducing bacteria

Abundant, micrometer-scale, spherical aggregates of 2- to 5-nanometer-diameter sphalerite (ZnS) particles formed within natural biofilms dominated by relatively aerotolerant sulfate-reducing bacteria of the family Desulfobacteriaceae. The biofilm zinc concentration is about 10(6) times that of associated groundwater (0.09 to 1.1 parts per million zinc). Sphalerite also concentrates arsenic (0.01 weight %) and selenium (0.004 weight %). The almost monomineralic product results from buffering of sulfide concentrations at low values by sphalerite precipitation. These results show how microbes control metal concentrations in groundwater- and wetland-based remediation systems and suggest biological routes for formation of some low-temperature ZnS deposits.

Organic cosolvents and hen egg white lysozyme folding

Studies on the influence of organic cosolvents on lysozyme folding have been reported. As most of the researches are confined to a few specific molecules and focus on equilibrium states, less is known about the effect on folding dynamics. We have studied the influence of six soluble organic cosolvents on hen egg white lysozyme heat induced denaturation and refolding dynamics. It was found that trifluoroethanol (TFE) can change the folding pathway significantly. With the presence of TFE, the overshot phenomenon generally observed in lysozyme folding at 222 nm disappears. The common mechanism of how organic cosolvents influence folding is analyzed. The heat induced denaturation temperature was found to have a quantitative relationship with the slow phase rate constant during folding. We discuss this finding and hypothesize that it is due to the similar influence of organic cosolvent on the transition state of heat denaturation and refolding.

[Effects of exogenous wild-type p53 gene expression on sensitivity to chemotherapeutic agents in human lung cancer cell]

BACKGROUND

To investigate the effects of exogenous wild-type p53 (wtp53) gene expression on sensitivity to chemotherapeutic agents with different mechanism of action in human lung cancer cells.

METHODS

A human lung cancer cells line 801-D with point mutation of p53 was transfected with either constructed recombinant plasmid pEGFP-p53 , which expressed wtp53 or pEGFP vector. The expression of neo and wtp53 gene in anti-G418 clone , 801-D vector and 801-D-wtp53 , were detected by PCR. The functional activity of transfected wtp53 was demonstrated by partly 801-D apoptosis. 3 H-TdR uptake assay was taken for drug sensitivity measure according to standard procedures. Flow cytometry was employed to determine cell death.

RESULTS

Sensitivity of 801-D-wtp53 to cisplatin and 5-fluorouracil was higher than that of 801-D vector by 9. 7 and 11. 4 fold respectively. There was no significant difference for other DNA-damaging agents and non-DNA-damaging agents , such as etoposide and adriamycin , vincristine and methylenum Caeruleum. Analysis of DNA ladder by gel electrophoresis and morphological observation showed cell necrosis characteristics.

CONCLUSIONS

801-D cell line shows a selective sensitization to DNA-damaging agents when exogenous wtp53 is expressed. The increased sensitivity to cisplatin by exogenous wtp53 expression may be through non-apoptosis pathway. This study results provide experimental bases for comprehensive treatment of lung cancer.

[Inhibition of lung cancer cell line growth in vitro by telomerase anti-sense oligonucleotides.]

BACKGROUND

To research the inhibition of lung cancer cell line by telomerase anti-sense DNA , and explore the possibility of its clinical application.

METHODS

A phosphorothioate oligonucleotide (PS-ODN) with sequence identical to the repeat sequence of the mammaliam telomere [5'- d(TTAGGG)-3'] and a control scrambled sequence 5'- d(TGTGAG)-3' were incubated with a lung cancer cell line 801-D , and the effects of PS-ODN on cell line growth , colony-forming and growth shape were detected.

RESULTS

Telomerase anti-sense DNA inhibited telomerase activation cell line 801-D growth and colony-forming. The activity of the 6-mer telomere mimic demonstrated a dose dependency. No activity was observed with the scrambled controls.

CONCLUSIONS

These results demonstrated the inhibitive effects of a short hexameric oligonucleotide telomere mimic on lung cancer cell line growth in vitro and the potential utility of telomerase anti-sense DNA as cancer cell inhibitors.