Combined determination of Epstein-Barr virus-related antibodies and antigens for diagnosis of nasopharyngeal carcinoma.

Background And Objective: With the development of molecular biology in recent years, many indexes for detecting Epstein-Barr virus (EBV) have been developed. This study was to evaluate the diagnostic value of combined determination of EBV-related antibodies and antigens, including VCA-IgA, EA-IgA, EBV-DNase antibody and EBV-DNA, in diagnosing nasopharyngeal carcinoma (NPC).

Methods: Serum and plasma samples from 160 untreated NPC patients and 76 healthy donors were collected.

[Clinical study of postoperative intraperitoneal chemotherapy combined with systemic chemotherapy for serosa-involved colorectal cancer].

Objective: To compare the clinical efficacy of postoperative intraperitoneal chemotherapy combined with systemic chemotherapy to systemic chemotherapy alone for serosa-involved colorectal cancer.

Methods: According to the criteria of serosa-involving in colorectal cancer, 332 cases were divided into 2 groups prospectively without randomization. Study group(n=166) was treated with intraperitoneal chemotherapy combined with systemic chemotherapy, and control group(n=166) with systemic chemotherapy alone.

Cerebrospinal fluid concentration of brain-derived neurotrophic factor and cognitive function in non-demented subjects.

Background: Brain-derived neurotrophic factor (BDNF) is an activity-dependent secreted protein that is critical to organization of neuronal networks and synaptic plasticity, especially in the hippocampus. We tested hypothesis that reduced CSF BDNF is associated with age-related cognitive decline.

Methodology/principal Findings, And Conclusions/significance: CSF concentration of BDNF, Abeta(42) and total tau were measured in 128 cognitively normal adults (Normals), 21 patients with Alzheimer's disease (AD), and nine patients with Mild Cognitive Impairment.

Visualizing the disassembly of S. cerevisiae Rad51 nucleoprotein filaments.

Rad51 is the core component of the eukaryotic homologous recombination machinery and assembles into elongated nucleoprotein filaments on DNA. We have used total internal reflection fluorescence microscopy and a DNA curtain assay to investigate the dynamics of individual Saccharomyces cerevisiae Rad51 nucleoprotein filaments. For these experiments the DNA molecules were end-labeled with single fluorescent semiconducting nanocrystals.

Functional interactions of meiotic recombination factors Rdh54 and Dmc1.

Genetic studies in budding and fission yeasts have provided evidence that Rdh54, a Swi2/Snf2-like factor, synergizes with the Dmc1 recombinase to mediate inter-homologue recombination during meiosis. Rdh54 associates with Dmc1 in the yeast two-hybrid assay, but whether the Rdh54-Dmc1 interaction is direct and the manner in which these two recombination factors may functionally co-operate to accomplish their biological task have not yet been defined. Here, using purified Schizosaccharomyces pombe proteins, we demonstrate complex formation between Rdh54 and Dmc1 and enhancement of the recombinase activity of Dmc1 by Rdh54.

One-step preparation of glycopeptide microspheres based on alpha-amino acid-N-carboxyanhydride polymerization using interfacial protocols.

A type of polysaccharide-polypeptide hybrid material, chitin derivative with polypeptide side chains was prepared by the graft copolymerization of L-leucine N-carboxyanhydride triggered by water-soluble chitin (WSC). The studies on surface tension and aggregation demonstrated surface activity of WSC. Using this extraordinary property, the microspheres were synchronously obtained via interfacial polymerization.

Cine computed tomography without respiratory surrogate in planning stereotactic radiotherapy for non-small-cell lung cancer.

Purpose: To determine whether cine computed tomography (CT) can serve as an alternative to four-dimensional (4D)-CT by providing tumor motion information and producing equivalent target volumes when used to contour in radiotherapy planning without a respiratory surrogate.

Methods And Materials: Cine CT images from a commercial CT scanner were used to form maximum intensity projection and respiratory-averaged CT image sets. These image sets then were used together to define the targets for radiotherapy.

Effects of respiration-averaged computed tomography on positron emission tomography/computed tomography quantification and its potential impact on gross tumor volume delineation.

Purpose: Patient respiratory motion can cause image artifacts in positron emission tomography (PET) from PET/computed tomography (CT) and change the quantification of PET for thoracic patients. In this study, respiration-averaged CT (ACT) was used to remove the artifacts, and the changes in standardized uptake value (SUV) and gross tumor volume (GTV) were quantified.

Methods And Materials: We incorporated the ACT acquisition in a PET/CT session for 216 lung patients, generating two PET/CT data sets for each patient.

Synthesis and properties of chitosan/polypeptide bioconjugate composite.

Adhesive polypeptide containing the key component of mussel adhesive protein was synthesized by ring-opening polymerization, and a hybrid material of the adhesive polypeptide and chitosan was prepared through the solution method. Some strong hydrogen bond interaction existed, but without the chemical bond between chitosan and polypeptide molecular in the composites, which was demonstrated by IR and XRD. Tensile strength and elongation-at-break of the composite increased with the increase of the polypeptide content.

In situ preparation of glycoconjugate hollow microspheres mimics the extracellular matrix via interfacial polymerization.

A novel chitin-graft-polyleucine microsphere with hollow construction was prepared via ring-opening polymerization initiated with chitin based on interfacial protocol. The FT-IR and (1)H NMR analysis demonstrated the conjugation with regulated graft length. The study provided a facile one-step route to obtain microsphere with glycoconjugation structure.

Molecular anatomy of the recombination mediator function of Saccharomyces cerevisiae Rad52.

A helical filament of Rad51 on single-strand DNA (ssDNA), called the presynaptic filament, catalyzes DNA joint formation during homologous recombination. Rad52 facilitates presynaptic filament assembly, and this recombination mediator activity is thought to rely on the interactions of Rad52 with Rad51, the ssDNA-binding protein RPA, and ssDNA. The N-terminal region of Rad52, which has DNA binding activity and an oligomeric structure, is thought to be crucial for mediator activity and recombination.

ATP-dependent chromatin remodeling by the Saccharomyces cerevisiae homologous recombination factor Rdh54.

Saccharomyces cerevisiae RDH54 is a key member of the evolutionarily conserved RAD52 epistasis group of genes needed for homologous recombination and DNA double strand break repair. The RDH54-encoded protein possesses a DNA translocase activity and functions together with the Rad51 recombinase in the D-loop reaction. By chromatin immunoprecipitation (ChIP), we show that Rdh54 is recruited, in a manner that is dependent on Rad51 and Rad52, to a site-specific DNA double strand break induced by the HO endonuclease.

[Correlation of BrdU incorporation with activation and cytokine expression of T cells].

Aim: To investigate the correlation of BrdU incorporation with the activation and cytokine expression of T cells.

Methods: PBMCs from healthy persons were isolated and stimulated by PMA plus Ionomycin at different periods of time, BrdU was then added to the cells one hour before the end of culture. The cells were harvested and stained with anti-BrdU, anti-cell surface and intracellular antibodies.

RECQL5/Recql5 helicase regulates homologous recombination and suppresses tumor formation via disruption of Rad51 presynaptic filaments.

Members of the RecQ helicase family play critical roles in genome maintenance. There are five RecQ homologs in mammals, and defects in three of these (BLM, WRN, and RECQL4) give rise to cancer predisposition syndromes in humans. RECQL and RECQL5 have not been associated with a human disease.

Four-dimensional cone beam CT with adaptive gantry rotation and adaptive data sampling.

We have developed a new four-dimensional cone beam CT (4D-CBCT) on a Varian image-guided radiation therapy system, which has radiation therapy treatment and cone beam CT imaging capabilities. We adapted the speed of gantry rotation time of the CBCT to the average breath cycle of the patient to maintain the same level of image quality and adjusted the data sampling frequency to keep a similar level of radiation exposure to the patient. Our design utilized the real-time positioning and monitoring system to record the respiratory signal of the patient during the acquisition of the CBCT data.

Chromatin remodeling and cancer, Part II: ATP-dependent chromatin remodeling.

Connections between perturbations that lie outside of our genome, that is, epigenetic alternations, and tumorigenesis have become increasingly apparent. Dynamic chromatin remodeling of the fundamental nucleosomal structure (covered in this review) or the covalent marks residing in the histone proteins that make up this structure (covered previously in part I) underlie many fundamental cellular processes, including transcriptional regulation and DNA-damage repair. Dysregulation of these processes has been linked to cancer development.

Chromatin remodeling and cancer, Part I: Covalent histone modifications.

Dynamic chromatin remodeling underlies many, if not all, DNA-templated biological processes, including gene transcription; DNA replication and repair; chromosome condensation; and segregation and apoptosis. Disruption of these processes has been linked to the development and progression of cancer. The mechanisms of dynamic chromatin remodeling include the use of covalent histone modifications, histone variants, ATP-dependent complexes and DNA methylation.

[Interleukin-12 restores and promotes the T-cell immune function inhibited by 5-fluorouracil].

Background & Objective: Currently, 5-fluorouracil (5-FU) is still one of the widely applied chemotherapeutic agents for tumors. Interleukin-12 (IL-12) can promote the differentiation of Th1 cells and induce the production of interferon-gamma (IFN-gamma) by CD8+ T cells. This study was to investigate the suppression mechanism of 5-FU on the immune response mediated by T cells from normal human peripheral blood, and to determine the effect of IL-12 on the immune suppression induced by 5-FU.

Design of respiration averaged CT for attenuation correction of the PET data from PET/CT.

Our previous patient studies have shown that the use of respiration averaged computed tomography (ACT) for attenuation correction of the positron emission tomography (PET) data from PET/CT reduces the potential misalignment in the thorax region by matching the temporal resolution of the CT to that of the PET. In the present work, we investigated other approaches of acquiring ACT in order to reduce the CT dose and to improve the ease of clinical implementation. Four-dimensional CT (4DCT) data sets for ten patients (17 lung/esophageal tumors) were acquired in the thoracic region immediately after the routine PET/CT scan.

Bipartite stimulatory action of the Hop2-Mnd1 complex on the Rad51 recombinase.

The HOP2 and MND1 genes are indispensable for meiotic recombination. The products of these genes associate to form a stable heterodimeric complex that binds DNA and stimulates the recombinase activity of Rad51 and Dmc1. Here we conduct molecular studies to delineate the action mechanism of the Hop2-Mnd1 complex.

Synergistic action of the Saccharomyces cerevisiae homologous recombination factors Rad54 and Rad51 in chromatin remodeling.

Rad54, a member of the Swi2/Snf2 protein family, works in concert with the RecA-like recombinase Rad51 during the early and late stages of homologous recombination. Rad51 markedly enhances the activities of Rad54, including the induction of topological changes in DNA and the remodeling of chromatin structure. Reciprocally, Rad54 promotes Rad51-mediated DNA strand invasion with either naked or chromatinized DNA.

Polymorphisms in the myosin light chain kinase gene that confer risk of severe sepsis are associated with a lower risk of asthma.

Background: Myosin light chain kinase (MYLK) is a multifunctional protein involved in regulation of airway hyperreactivity and other activities relevant to asthma.

Objective: To determine the role of MYLK gene variants in asthma among African Caribbean and African American populations.

Methods: We performed association tests between single nucleotide polymorphisms (SNPs) in the MYLK gene and asthma susceptibility and total serum IgE concentrations in 2 independent, family-based populations of African descent.

A DNA-translocating Snf2 molecular motor: Saccharomyces cerevisiae Rdh54 displays processive translocation and extrudes DNA loops.

We have used total internal reflection fluorescence microscopy (TIRFM) to investigate the characteristics of the yeast homologous recombination factor Rdh54 on DNA. Our results demonstrate translocation of Rdh54 on DNA and extrusion of DNA loops by Rdh54 in an ATP hydrolysis-dependent manner. The translocating Rdh54 was highly processive and displayed a variety of behavior, including variations in translocation rate and distance, pauses, and reversals.

Vitreoscilla hemoglobin aids respiration under hypoxic conditions in its native host.

When Vitreoscilla were grown in medium containing 60mM sodium nitrite under both normal and limited aeration conditions, the levels of Vitreoscilla hemoglobin (VHb) were decreased by greater than 90%, while the levels of the terminal respiratory oxidase, cytochrome bo, were increased 350% under normal aeration and 7-23% under limited aeration. Cytochrome function, as measured by both NADH and ubiquinol oxidases for cells grown under both conditions, increased in parallel (by 150-222% and 8-56%, respectively, for the two activities). Nitrite in the medium inhibited Vitreoscilla growth at both normal and limited aeration.

[Comparing the influencing factors of anastomotic bleeding in rectal carcinoma resection between laparoscopic and open radical approaches].

Objective: To observe the occurrence of anastomotic bleeding following laparoscopic and open radical resection for rectal carcinoma, and to explore its contributing factors.

Methods: Two hundred and sixty-three cases of rectal carcinoma undergone radical resection were divided into 2 groups, laparoscopic surgery (LS) group (n=86) and open surgery (OS) group (n=177). According to the different locations of anastomotic stoma and with or without preventive colostomy, the two groups were divided into AR sub-group and LAR/UAR sub-group, colostomy sub-group and non-colostomy sub-group.