ESTABLISHMENT OF THE IN VITRO DOSE-RESPONSE CALIBRATION CURVE FOR X-RAY-INDUCED MICRONUCLEI IN HUMAN LYMPHOCYTES.

The cytokinesis-block micronucleus assay has proven to be a reliable technique for biological dosimetry. This study aimed to establish the dose-response curve for X-ray-induced micronucleus. Peripheral blood samples from three healthy donors were irradiated with various doses and scoring criteria by the micronuclei (MN) in binucleated cells. The results showed that the frequency of MN increased with the elevation of radiation dose. CABAS and Dose Estimate software were used to fit the MN and dose into a linear quadratic model, and the results were compared. The linear and quadratic coefficients obtained by the two software were basically the same and were comparable with published curves of similar radiation quality and dose rates by other studies. The dose-response curve established in this study can be used as an alternative method for in vitro dose reconstruction and provides a reliable tool for biological dosimetry in accidental or occupational radiation exposures.

The DNA Pol ϵ stimulatory activity of Mrc1 is modulated by phosphorylation.

DNA replication checkpoint (Mec1-Mrc1-Rad53 in budding yeast) is an evolutionarily conserved surveillance system to ensure proper DNA replication and genome stability in all eukaryotes. Compared to its well-known function as a mediator of replication checkpoint, the exact role of Mrc1 as a component of normal replication forks remains relatively unclear. In this study, we provide in vitro biochemical evidence to support that yeast Mrc1 is able to enhance the activity of DNA polymerase ϵ (Pol ϵ), the major leading strand replicase. Mrc1 can selectively bind avidly to primer/template DNA bearing a single-stranded region, but not to double-stranded DNA (dsDNA). Mutations of the lysine residues within basic patch 1 (BP1) compromise both DNA binding and polymerase stimulatory activities. Interestingly, Mrc1-3D, a mutant mimicking phosphorylation by the Hog1/MAPK kinase during the osmotic stress response, retains DNA binding but not polymerase stimulation. The stimulatory effect is also abrogated in Mrc1 purified from cells treated with hydroxyurea (HU), which elicits replication checkpoint activation. Taken together with previous findings, these results imply that under unperturbed condition, Mrc1 has a DNA synthesis stimulatory activity, which can be eliminated via Mrc1 phosphorylation in response to replication and/or osmotic stresses.

The tumor-stroma ratio is an independent predictor for survival in nasopharyngeal cancer.

BACKGROUND: The tumor-stroma ratio (TSR) has been identified as a new and practicable prognostic histological characteristic of solid tumors. The aim of this study was to evaluate the prognostic value of the TSR in nasopharyngeal cancer (NPC). PATIENTS AND METHODS: A total of 93 patients who presented with NPC from 2004 to 2007 were studied. Radiotherapy with or without chemotherapy was administered according to their Union for International Cancer Control (UICC) stages. The TSR was assessed visually on hematoxylin and eosin-stained tissue sections of biopsy specimens by 2 independent observers. RESULTS: The 5-year overall survival (OS) and disease-free survival (DFS) rates were 66.67% and 54.91%, respectively, in the stroma-poor group and 40.48% and 33.33%, respectively, in the stroma-rich group. Both the 5-year OS and DFS rates in the stroma-poor group were significantly better than those in the stroma-rich group (p < 0.05). In a multivariate analysis, the TSR was identified as a highly significant prognostic factor for the 5-year OS (hazard ratio (HR) 1.999; p = 0.030) and the 5-year DFS (HR 1.925; p = 0.042). CONCLUSION: Stroma-rich tumors were associated with poor prognosis and an increased risk of relapse, which may serve as a new prognostic histological characteristic in NPC.

Transvaginal color Doppler sonography predicts ovarian interstitial fibrosis and microvascular injury in women with ovarian endometriotic cysts.

OBJECTIVE: To determine novel predictors of ovarian interstitial fibrosis and microvascular injury associated with ovarian endometriotic cysts (OECs). DESIGN: Case-control study. SETTING: The gynecology unit of an affiliated hospital in China. POPULATION: Women <40 years of age with OECs or benign ovarian tumors (controls). METHODS: Transvaginal color Doppler sonography was performed preoperatively to detect ovarian interstitial flow. Postoperatively, expressions of transforming growth factor-ß1 (TGF-ß1) and thrombospondin-1 (TSP-1), as well as microvessel density in ovarian interstitial, were analyzed using immunohistochemistry. MAIN OUTCOME AND MEASURES: Ovarian interstitial flow and expressions of TGF-ß1, TSP-1, and microvessel density. RESULTS: Compared with controls, ovarian interstitial flow in the study group was decreased and arterial spectra indicated significantly higher resistance indices. Microvessel density was reduced, but TGF-ß1 and TSP-1 were elevated in the study group. There was a positive correlation between TGF-ß1 and TSP-1. There were negative correlations between TGF-ß1 and microvessel density, and between TSP-1 and microvessel density. Microvessel density and resistance indices were negatively correlated, whereas the correlations of TGF-ß1 and TSP-1 with resistance indices were positive. CONCLUSIONS: Resistance indices are consistent with pathological indices. Changes in resistance indices in ovaries with endometriosis are related to interstitial fibrosis and microvascular injury.

Ovarian interstitial blood flow changes assessed by transvaginal colour Doppler sonography: predicting ovarian endometrioid cyst-induced injury to ovarian interstitial vessels.

PURPOSE: To evaluate the blood flow changes and their relationships to microvessel density (MVD) and thrombospondin-1 (TSP-1) by transvaginal colour Doppler sonography (TV-CDS) in the ovarian interstitium to predict ovarian interstitial microvascular injury in the pathological process of ovarian endometrial cysts (OEC). METHODS: TV-CDS was preoperatively performed to detect blood flow changes in 60 patients with 76 ovarian endometrioid cysts, and flow classification and resistance indices (RI) values were recorded for analysis. Ovarian interstitial specimens with blood flow signals were collected for postoperative pathologic examination. TSP-1 protein was evaluated by immunohistochemistry and Western blot, TSP-1 mRNA by reverse transcriptase polymerase chain reaction, microvessels by CD34 antibody, and MVD by image analysis. Thirty age-matched patients with benign ovarian tumours served as controls. RESULTS: Blood flow, most of star-shaped, within ovarian interstitial arteries in the OEC group was diminished; however, arterial spectra exhibited a high-resistance flow manifesting a significantly higher RI compared with that of the control group (P < 0.01). In ovarian interstitial specimens, there were significantly (P < 0.01) lower CD34-MVD and higher TSP-1 protein and mRNA in the OEC group than in the controls. CD34-MVD and TSP-1 showed remarkably negative correlation (rs = -0.76, P < 0.01). RI values correlated negatively with MVD values (rs = -0.91, P < 0.01), but positively with TSP-1 (rs = 0.81, P < 0.01), while flow classification correlated positively with MVD values (rs = 0.66, P < 0.01), but negatively with TSP-1 (rs = -0.54, P < 0.01). CONCLUSIONS: Changes in CD34-MVD and TSP-1 reflected ovarian interstitial microvascular injury of OEC, pathologically supported the findings of blood flow changes within ovarian interstitial arteries, and prospectively predicted OEC-induced ovarian interstitial vessel injury. This has important clinical value: early treatment, instead of allowing the cyst to become bigger, is of great importance for OEC patients, because a greater number of functional tissue blood vessels would be destroyed as the disease progresses.

Localization and functional analysis of SeMNPV IE1 in mammalian cells.

In this paper, the function of the ie1 gene from baculovirus Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV), belonging to group II nucleopolyhedrovirus, was studied in mammalian cells. We amplified the SeMNPV ie1 gene and expressed it by fusing to the C terminal of enhanced GFP protein in HEK 293 cells. Confocal microscopy revealed that the IE1-GFP fusion protein was localized in the nucleus of the mammalian cells. The promoter sequences of AcMNPV gp64, SeMNPV F protein and Drosophila hsp70 were also analyzed, to further study the function of SeMNPV IE1. The results showed that, in the absence of the hr sequence, IE1 improved the expression of the F promoter but didn't influence the gp64 promoter significantly, but IE1 moderately stimulated the hsp70 promoter.

A Capacitive Humidity Sensor Based on Multi-Wall Carbon Nanotubes (MWCNTs).

A new type of capacitive humidity sensor is introduced in this paper. The sensor consists of two plate electrodes coated with MWCNT films and four pieces of isolating medium at the four corners of the sensor. According to capillary condensation, the capacitance signal of the sensor is sensitive to relative humidity (RH), which could be transformed to voltage signal by a capacitance to voltage converter circuit. The sensor is tested using different saturated saline solutions at the ambient temperature of 25 °C, which yielded approximately 11% to 97% RH, respectively. The function of the MWCNT films, the effect of electrode distance, the temperature character and the repeatability of the sensor are discussed in this paper.