[Clinical characteristics and risk factors of periventricular-intraventricular hemorrhage in extremely low birth weight infants].

Objective: To analyze the clinical characteristics and risk factors of periventricular-intraventricular hemorrhage (PIVH) in extremely low birth weight infants (ELBWI). Methods: From January 2019 to January 2022, the clinical data of 238 ELBWI admitted to the intensive care unit of Henan Provincial Children's Hospital within 1 week after birth and regular head color ultrasound examination were retrospective reviewed. The infants were divided into PIVH group and non-PIVH group according to whether PIVH occurred. The incidence and time of PIVH were described, and the differences in basic clinical features, perinatal conditions, postnatal treatment and complications between the two groups were compared. The risk factors of PIVH in ELBWI were further explored by multivariate binary logistic regression analysis. Results: Among 238 ELBWI (146 males and 92 females), 82 cases (34.5%) developed PIVH, including 28 cases (11.8%) of severe PIVH and 54 cases (22.7%) of mild PIVH. Among the 82 cases of PIVH, 68 cases occurred within 3 days after birth. Gestational age [(27.4±1.5) weeks vs (27.8±1.5) weeks, P=0.012], gestational diabetes mellitus [0 vs 9.0%(14/156), P=0.005], fibrinogen (FIB) [(1.8±0.5) g/L vs (2.7±0.9) g/L, P=0.012] were lower in PIVH group than in non-PIVH group. However, intrauterine distress [46.3%(38/82) vs 11.5%(18/156), P<0.001], birth asphyxia [85.4%(70/82) vs 62.8%(98/156), P<0.001], patent ductus arteriosus (PDA) [65.9%(54/82) vs 51.3%(80/156）, P=0.017], failure to withdraw invasive ventilator within 1 week [82.9%(14/82) vs 67.3%(105/156), P=0.010], use of vasoactive drugs within 1 week [28.0%(23/82) vs 15.4%(24/156), P=0.020], acidosis [28.0%(23/82) vs 12.2%(19/156), P=0.002], and hemorrhagic disease [18.3%(15/82) vs 7.1%(11/156), P=0.008] were higher in PIVH group than in non-PIVH group. Multivariate binary logistic regression analysis found that the risk factors for PIVH in ELBWI were acidosis (OR=2.257, 95%CI: 1.104-4.614, P=0.026), use of vasoactive drugs within 1 week (OR=2.274, 95%CI: 1.148-4.504, P=0.018), bleeding disorders (OR=2.583, 95%CI: 1.075-6.206, P=0.034) use of vasoactive drugs within 1 week (OR=2.301, 95%CI: 1.153-4.591, P<0.001). Conclusions: The incidence of PIVH in ELBWI is high, which mostly occurs within 3 days after birth. Acidosis, hemorrhagic disease, use of vasoactive agents within 1 week and failure to evacuate invasive ventilators within 1 week may increase the risk of PIVH in ELBWI.

Optimal reference genes for real-time quantitative PCR and the expression of sigma factors in Acidithiobacillus caldus under various conditions.

AIMS: Acidithiobacillus caldus is an important sulphur-oxidizing bacterium that plays crucial roles in the bioleaching industry. This study aims to analyse the optimal reference gene for real-time quantitative PCR (RT-qPCR) under different conditions and investigate the transcription levels of the sigma factor genes in the stress response. METHODS AND RESULTS: We selected six housekeeping genes and analysed them via RT-qPCR using two energy resources, under four stress conditions. Three statistical approaches BestKeeper, geNorm, and NormFinder were utilized to determine transcription stability of these reference genes. The gapdH gene was the best internal control gene using elemental sulphur as an energy resource and under heat stress, map was the best internal control gene under pH and osmotic stress, era was the best internal control gene for the K2 S4 O6 energy resource, and rpoC was the best internal control gene under Cu2+ stress. Furthermore, the expressional levels of 11 sigma factors were analysed by RT-qPCR in the stress response. CONCLUSIONS: Stable internal control genes for RT-qPCR analysis of A. caldus were determined, and the expression patterns of sigma factor genes of A. caldus were investigated. SIGNIFICANCE AND IMPACT OF THE STUDY: The identification of the optimal reference gene and analysis of transcription levels of sigma factors in A. caldus can provide clues for reference gene selection and the study of sigma factor function.

[Development of a quantitative serum assay of Golgi protein 73 in hepatocellular carcinoma using xMAP technology].

Objective: To establish a quantitative assay of serum Golgi protein 73 (GP73) using xMAP technology and evaluate its performance. Methods: Monoclonal antibodies against GP73 were prepared and purified, and antibody pair screening was performed by double-antibody sandwich enzyme-linked immunosorbent assay. The screened antibodies were used to construct a Luminex liquid chip detection system, and the analysis performance of the detection system was evaluated. The serum levels of GP73 were detected in 90 clinical samples from healthy controls and patients with chronic hepatitis B infection (CHB) and hepatocellular carcinoma (HCC). Results: Five anti-GP73 monoclonal antibodies were prepared and purified, and 5 antibody pairs were successfully screened. The Luminex liquid chip detection system of GP73 was successfully constructed using 8F10D1 and 10B9F11 antibody pairs. The analytical performance evaluation showed that the sensitivity of this system was 0.25 ng/ml and the dynamic range was 0.25-100 ng/ml. No cross reactivity was observed. The intra- and inter-assay variation for GP73 was <8% and <11%, respectively. The recovery was 83%-92%. The linear regression equation was y=1.141x+ 6.436 (r(2)=0.998 4, P<0.001). The GP73 concentrations in the serum samples of healthy control, CHB group, and HCC group were 42.8 (38.68, 55.90) ng/ml, 61.49 (43.59, 81) ng/ml, and 122.78 (49.36 liter, 264.55) ng/ml, respectively. The levels of GP73 in HCC group were significantly higher than those in CHB group and healthy controls (P<0.05). Moreover, the levels of GP73 in CHB group were significantly higher than those in healthy controls (P<0.05). Conclusions: A liquid chip detection system of GP73 was successfully constructed. It provides a powerful tool for the clinical application of GP73 in the future.

[Effect of clinical characteristics on relapse of alcohol dependence: a prospective cohort study].

OBJECTIVE: To investigate whether craving and demographic factors to predict relapse in alcohol dependence. METHODS: This study was a prospective cohort study. From August 2017 to August 2018, 158 Han male inpatients who met the diagnositic and statistical manual disorders-fourth version(DSM-IV) alcohol dependence diagnostic criteria were recruited from three mental hospitals in China. The participants were interviewed at baseline and followed up by telephone after 3 months for assessment. The baseline assessment after the acute withdrawal period included demographic data and alcohol-related data, clinical institute withdrawal assessment-advanced revised (CIWA-Ar), withdrawal and cue-induced craving on visual analog scale (VAS), Michigan alcoholism screening test (MAST), self-rating anxiety scale (SAS), self-rating depression scale (SDS) and alcohol urge questionnaire (AUQ). According to the follow-up results, "relapse" was defined as the consumption of beverages containing ethanol at any time during the follow-up study, and "time to relapse" was defined as the number of days from the first drinking to the baseline. Whether relapse occurred and the time to relapse were the primary endpoints. Cox proportional hazard regression model was used to analyze the factors affecting the relapse of alcohol dependence. RESULTS: In the study, 158 alcohol dependence patients were finally included, age from 21 to 60 years, with the mean age of (40.31±9.14) years. The relapse rate was 63.7% three months after baseline assessment. According to Cox univariate analysis and multivariate analysis, the age (OR=0.975, P=0.030) and CIWA-Ar scores (OR=1.126, P=0.010) significantly predicted relapse. And there was no significant difference in education level, marital status, withdrawal and cue-induced craving on VAS, SAS and SDS between the relapse group and the non-relapse group (P>0.05). CONCLUSION: Age and severity of alcohol-dependent withdrawal symptoms during hospitalization are significantly related to relapse for alcohol in alcohol-dependent patients. To be exact, the older age is a protective factor, that is to say, the younger patients are prone to relapse, while the risk of relapse is raised by the higher severity of withdrawal symptoms. However, neither cue-induced nor withdrawal craving can predict relapse of alcohol-dependent patients.

Epigenomics alternations and dynamic transcriptional changes in responses to 5-fluorouracil stimulation reveal mechanisms of acquired drug resistance of colorectal cancer cells.

A drug-induced resistant cancer cell is different from its parent cell in transcriptional response to drug treatment. The distinct transcriptional response pattern of a drug-induced resistant cancer cell to drug treatment might be introduced by acquired DNA methylation aberration in the cell exposing to sustained drug stimulation. In this study, we performed both transcriptional and DNA methylation profiles of the HCT-8 wild-type cells (HCT-8/WT) for human colorectal cancer (CRC) and the 5-fluorouracil (5-FU)-induced resistant cells (HCT-8/5-FU) after treatment with 5-FU for 0, 24 and 48 h. Integrated analysis of transcriptional and DNA methylation profiles showed that genes with promoter hypermethylation and concordant expression silencing in the HCT-8/5-FU cells are mainly involved in pathways of pyrimidine metabolism and drug metabolism-cytochrome P450. Transcriptional analysis confirmed that genes with transcriptional differences between a drug-induced resistant cell and its parent cell after drug treatment for a certain time, rather than their primary transcriptional differences, are more likely to be involved in drug resistance. Specifically, transcriptional differences between the drug-induced resistant cells and parental cells after drug treatment for 24 h were significantly consistent with the differentially expressed genes (termed as CRG5-FU) between the tissues of nonresponders and responders of CRCs to 5-FU-based therapy and the consistence increased after drug treatment for 48 h (binomial test, P-value=1.88E-06). This study reveals a major epigenetic mechanism inducing the HCT-8/WT cells to acquire resistance to 5-FU and suggests an appropriate time interval (24-48 h) of 5-FU exposure for identifying clinically relevant drug resistance signatures from drug-induced resistant cell models.

[Verification of skin paste electrodes used in wireless polysomnography].

OBJECTIVE: To explore an electrode suitable for wireless portable sleep monitoring equipment and analyze the result of the signals of electrooculogram (EOG) and electroencephalography (EEG) collected by this kind of flexible electrodes. METHODS: The flexible electrodes were prepared by microelectromechanical systems (MEMS) technology. This kind of electrodes consisted parylene, chromium, and gold. Parylene, the flexible substrate of this kind of flexible electrodes, was of biocompatibility. Between parylene and gold there was an adhesion layer of chromium, which connected parylene and gold tightly. Then the flexible electrodes were stuck to medical adhesive tape. The electrodes were designed and made into a grid to make sure that the medical adhesive tape could tape on the skin tightly, so that the contact impedance between the electrodes and the skin would be reduced. Then the alternating current impedance of the electrode were tested by the CHI660E electrochemical workstation after the electrode was achieved. To make sure that this kind of electrodes could be used in EOG monitoring, the electrodes were connected to a wireless signal acquisition suite containing special biological signal acquisition and digital processing chip to gather different sites around the eyes and the electrical signals of different directions of the eye movements, then analyzed the signal-to-noise ratio of the EOG. At the end, the Philips A6 polysomnography was used to compare the noise amplitude of the EEG signals collected by the flexible electrode and the gold cup electrode. RESULTS: The electrodes stuck to the skin tightly, and these electrodes could collect signals that we wanted while the experiment was performed. The alternating current impedance of the flexible electrode was between 4 kΩ and 13 kΩ while with the frequency of alternating current under 100 Hz, most EEG signal frequencies were at this range. The EOG signals collected by the flexible electrodes were in line with the clinical requirements. The noise amplitude of EEG signals collected by the flexible electrodes was lower than that of the electrical signals collected by the gold cup electrodes. CONCLUSION: The flexible electrode could be taken into consideration as an alternative electrode for monitoring EOG and EEG signals, and the wireless portable sleep monitoring devices are to be further developed in the future.

[Fibroblast growth factor receptor 1 propagates estrogen and fluid shear stress driven proliferation and differentiation response in MC3T3-E1 cells].

Fluid shear stress (FSS) and estrogen exposure positively regulate bone metabolism. Fibroblast growth factor receptor 1 (FGFR1) plays a vital role in FSS-induced osteogenesis. An in vitro experiment with MC3T3-E1 cells combined with microarray analysis aided us in identification of the genes differentially expressed in response to FSS and highlighted the role of FGFR1 in this process. Both estrogen exposure and FSS increase methyl thiazol tetrazolium (MTT) values and alkaline phosphatase (ALP) activity, as well as the levels of Runt-related transcription factor 2 (Runx2) and osteocalcin (OCN). The effects of estrogen exposure and FSS were cumulative. Treatment with PD166866 inhibitor of the FGFR1 reduced the MTT values, increased ALP activity, and increased the levels of Runx2 and OCN. To investigate the regulation of FGFR1 signaling in stressed cells, a number of key components of the mitogen-activated protein kinase (MAPK) cascade were quantitatively examined. Neither estrogen nor FSS change the protein expression of extracellular signal-regulated kinase (ERK), Jun amino-terminal kinases (JNK) or p38, but positively influence their phosphorylation levels. Treatment with the FGFR1 inhibitor induced an increase in ERK phosphorylation levels only. In summary, estrogen exposure and FSS have a synergistic effect in osteogenesis. FGFR1 promotes osteoblast proliferation and inhibits the differentiation of osteoblasts. In MC3T3-E1 cells, FGFR1 signaling responds to independent and combined effects of estrogen and FSS. MAPK cascades participate in osteogenesis, but only the ERK signaling pathway responds to FGFR1.

[Status of fungal sepsis among preterm infants in 25 neonatal intensive care units of tertiary hospitals in China].

Objective: To analyze the prevalence and the risk factors of fungal sepsis in 25 neonatal intensive care units (NICU) among preterm infants in China, and to provide a basis for preventive strategies of fungal sepsis. Methods: This was a second-analysis of the data from the "reduction of infection in neonatal intensive care units using the evidence-based practice for improving quality" study. The current status of fungal sepsis of the 24 731 preterm infants with the gestational age of <34+0 weeks, who were admitted to 25 participating NICU within 7 days of birth between May 2015 and April 2018 were retrospectively analyzed. These preterm infants were divided into the fungal sepsis group and the without fungal sepsis group according to whether they developed fungal sepsis to analyze the incidences and the microbiology of fungal sepsis. Chi-square test was used to compare the incidences of fungal sepsis in preterm infants with different gestational ages and birth weights and in different NICU. Multivariate Logistic regression analysis was used to study the outcomes of preterm infants with fungal sepsis, which were further compared with those of preterm infants without fungal sepsis. The 144 preterm infants in the fungal sepsis group were matched with 288 preterm infants in the non-fungal sepsis group by propensity score-matched method. Univariate and multivariate Logistic regression analysis were used to analyze the risk factors of fungal sepsis. Results: In all, 166 (0.7%) of the 24 731 preterm infants developed fungal sepsis, with the gestational age of (29.7±2.0) weeks and the birth weight of (1 300±293) g. The incidence of fungal sepsis increased with decreasing gestational age and birth weight (both P<0.001). The preterm infants with gestational age of <32 weeks accounted for 87.3% (145/166). The incidence of fungal sepsis was 1.0% (117/11 438) in very preterm infants and 2.0% (28/1 401) in extremely preterm infants, and was 1.3% (103/8 060) in very low birth weight infants and 1.7% (21/1 211) in extremely low birth weight infants, respectively. There was no fungal sepsis in 3 NICU, and the incidences in the other 22 NICU ranged from 0.7% (10/1 397) to 2.9% (21/724), with significant statistical difference (P<0.001). The pathogens were mainly Candida (150/166, 90.4%), including 59 cases of Candida albicans and 91 cases of non-Candida albicans, of which Candida parapsilosis was the most common (41 cases). Fungal sepsis was independently associated with increased risk of moderate to severe bronchopulmonary dysplasia (BPD) (adjusted OR 1.52, 95%CI 1.04-2.22, P=0.030) and severe retinopathy of prematurity (ROP) (adjusted OR 2.55, 95%CI 1.12-5.80, P=0.025). Previous broad spectrum antibiotics exposure (adjusted OR=2.50, 95%CI 1.50-4.17, P<0.001), prolonged use of central line (adjusted OR=1.05, 95%CI 1.03-1.08, P<0.001) and previous total parenteral nutrition (TPN) duration (adjusted OR=1.04, 95%CI 1.02-1.06, P<0.001) were all independently associated with increasing risk of fungal sepsis. Conclusions: Candida albicans and Candida parapsilosis are the main pathogens of fungal sepsis among preterm infants in Chinese NICU. Preterm infants with fungal sepsis are at increased risk of moderate to severe BPD and severe ROP. Previous broad spectrum antibiotics exposure, prolonged use of central line and prolonged duration of TPN will increase the risk of fungal sepsis. Ongoing initiatives are needed to reduce fungal sepsis based on these risk factors.

Increased Th17 cells contribute to disease progression in patients with HBV-associated liver cirrhosis.

T helper (Th) 17 cells have been demonstrated to participate in the pathogenesis of HBV-associated liver damage. However, little is known regarding the immunopathogenic role of liver fibrosis in patients with HBV-associated liver cirrhosis. The aims of this study were to evaluate whether Th17 cells are related to disease progression in patients and to explore the possible mechanisms. The frequencies of circulating Th17 cells were analysed in 78 patients with hepatitis B and cirrhosis (Child A: 34; Child B: 22; Child C 22) and matched controls. Liver samples were collected from 13 patients with HBV-associated cirrhosis, 23 patients with chronic hepatitis B and 12 healthy controls for immunohistochemical analysis. IL-17 receptor expression was studied on liver biopsies and in human hepatic stellate cells as well as their response to recombinant IL-17 by flow cytometry. Patients with hepatitis B-associated cirrhosis with more severe disease displayed significant increases in peripheral numbers of Th17 cells as well as in IL-17 plasma levels. The increased intrahepatic IL-17(+) cells correlated positively with fibrotic staging scores and clinical progression from CHB to cirrhosis. Moreover, many IL-17(+) cells were located in fibrotic areas in the liver of patients with cirrhosis. In vitro, IL-17 together with IL-17-activated monocytes, could promote the activation of stellate cells, which, in turn, aggravated liver fibrosis and the inflammatory response. In summary, increased peripheral and intrahepatic Th17 cells are enriched in patients with hepatitis B and cirrhosis and contribute further to the severity of disease progression through induction of stellate cell activation.

Actin monomer binding proteins.

Small actin monomer binding proteins are essential components of the actin polymerization machinery. Originally thought of as passive buffers that prevent polymerization of actin monomers, recent discoveries elucidate how some actin monomer binding proteins can promote as well as inhibit polymerization, and how they cooperate to regulate actin assembly.

Development and preliminary application of novel genomewide SSR markers for genetic diversity analysis of an economically important bio-control agent Platygaster robiniae (Hymenoptera: Platygastridae).

Platygaster robiniae Buhl and Duso (Hymenoptera: Platygastridae) is an egg-larvae parasitoid of the black locust gall midge (Obolodiplosis robiniae) (Haldeman) (Diptera: Cecidomyiidae) which is a serious invasive pest in China, where it attacks an important hardwood species, the black locust tree, Robini pseudoacacia L. (Fabales: Fabaceae). Despite the use of P. robiniae as an effective biocontrol agent, the absence of sequence data and other molecular markers have limited its genetic applications for pest management in forests. Simple-sequence repeats (SSRs) are valuable molecular markers for population genetic structure studies. In the present study, we identified 14,123 SSRs, of which 7799 SSR primer pairs were successfully designed. Subsequently, 240 SSR were chosen and tested with 48 P. robiniae accessions from two geographically separated populations in north and south China. Of these, 34 were polymorphic, with an average of three alleles (Na) and four genotypes (NG) each. The average values of observed heterozygosity (Ho) was 0.3514, expected heterozygosity (He) 0.4167, Shannon's information index (I) 0.7143, and polymorphism information content (PIC) 0.3558, respectively. Neighbour joining analysis (bootstrap 1000) revealed that Chengdu (CD) and Dangdong (DD) popluations clustered into two main divisions, and some individuals from two popluations clustered together as the third devision, which indicated the gene flow and genetic differentiation were present between two populations. Our finding indicates that these SSR markers will be useful for further studies on the genotype identification and genetic mapping of the genus Platygaster.

Efficacy and safety of pegylated interferon alpha-2a therapy for chronic hepatitis C in HIV-infected patients with haemophilia.

The objective of this study was to evaluate the efficacy and safety of pegylated interferon (PEG-IFN) alpha-2a monotherapy in a cohort of Chinese haemophilic patients co-infected with human immunodeficiency virus (HIV)/hepatitis C virus (HCV) and undergoing highly active antiretroviral drugs therapy. Twenty-two (n = 22) patients with CD4 lymphocyte counts over 200 cells microL(-1) were treated with 180 microg of PEG-IFN alpha-2a subcutaneously once in a week for 48 weeks. HCV load (HCV RNA), HIV load (HIV RNA) and CD4 lymphocyte counts were measured at baseline and 4, 12, 24, 48 and 72 weeks after initiation of anti-HCV therapy. Efficacy and safety were analysed according to baseline CD4 status (> or =350 cells microL(-1)). Significant HCV-RNA decreases (>1 log(10) copies mL(-1)) were observed through week 72 after PEG-INF alpha-2a monotherapy across both CD4 strata. CD4 status was not associated with treatment outcomes as evaluated using rapid viral response rate (P = 0.655), early viral response rate (P = 0.387), end-of-treatment viral response rate (P = 1.000) or sustained viral response rate (SVR, P = 0.674). A sustained virological response was achieved in nine patients (41%), five with genotype 2a (83%) and four with genotype 1b (25%, P = 0.023). SVR was HCV genotype dependent. Eleven patients required a dose reduction in PEG-IFN alpha-2a. PEG-IFN alpha-2a monotherapy could be considered as a safe and effective option for the treatment of HCV infection in HIV patients with haemophilia, particularly in resource-limited settings. While higher CD4 lymphocyte counts resulted in greater HCV-RNA reduction, HCV genotype was a predictor for sustained virological response.

Natural ventilation for reducing airborne infection in hospitals.

High ventilation rate is shown to be effective for reducing cross-infection risk of airborne diseases in hospitals and isolation rooms. Natural ventilation can deliver much higher ventilation rate than mechanical ventilation in an energy-efficient manner. This paper reports a field measurement of naturally ventilated hospital wards in Hong Kong and presents a possibility of using natural ventilation for infection control in hospital wards. Our measurements showed that natural ventilation could achieve high ventilation rates especially when both the windows and the doors were open in a ward. The highest ventilation rate recorded in our study was 69.0 ACH. The airflow pattern and the airflow direction were found to be unstable in some measurements with large openings. Mechanical fans were installed in a ward window to create a negative pressure difference. Measurements showed that the negative pressure difference was negligible with large openings but the overall airflow was controlled in the expected direction. When all the openings were closed and the exhaust fans were turned on, a reasonable negative pressure was created although the air temperature was uncontrolled. The high ventilation rate provided by natural ventilation can reduce cross-infection of airborne diseases, and thus it is recommended for consideration of use in appropriate hospital wards for infection control. Our results also demonstrated a possibility of converting an existing ward using natural ventilation to a temporary isolation room through installing mechanical exhaust fans.

Gelsolin modulates phospholipase C activity in vivo through phospholipid binding.

Gelsolin and CapG are actin regulatory proteins that remodel the cytoskeleton in response to phosphatidylinositol 4,5-bisphosphate (PIP2) and Ca2+ during agonist stimulation. A physiologically relevant rise in Ca2+ increases their affinity for PIP2 and can promote significant interactions with PIP2 in activated cells. This may impact divergent PIP2- dependent signaling processes at the level of substrate availability. We found that CapG overexpression enhances PDGF-stimulated phospholipase Cgamma (PLCgamma) activity (Sun, H.-q., K. Kwiatkowska, D.C. Wooten, and H.L. Yin. 1995. J. Cell Biol. 129:147-156). In this paper, we examined the ability of gelsolin and CapG to compete with another PLC for PIP2 in live cells, in semiintact cells, and in vitro. We found that CapG and gelsolin overexpression profoundly inhibited bradykinin-stimulated PLCbeta. Inhibition occurred at or after the G protein activation step because overexpression also reduced the response to direct G protein activation with NaF. Bradykinin responsiveness was restored after cytosolic proteins, including gelsolin, leaked out of the overexpressing cells. Conversely, exogenous gelsolin added to permeabilized cells inhibited response in a dose-dependent manner. The washout and addback experiments clearly establish that excess gelsolin is the primary cause of PLC inhibition in cells. In vitro experiments showed that gelsolin and CapG stimulated as well as inhibited PLCbeta, and only gelsolin domains containing PIP2-binding sites were effective. Inhibition was mitigated by increasing PIP2 concentration in a manner consistent with competition between gelsolin and PLCbeta for PIP2. Gelsolin and CapG also had biphasic effects on tyrosine kinase- phosphorylated PLCgamma, although they inhibited PLCgamma less than PLCbeta. Our findings indicate that as PIP2 level and availability change during signaling, cross talk between PIP2-regulated proteins provides a selective mechanism for positive as well as negative regulation of the signal transduction cascade.

Effects of CapG overexpression on agonist-induced motility and second messenger generation.

Actin modulating proteins that bind polyphosphoinositides, such as phosphatidylinositol 4, 5-bisphosphate (PIP2), can potentially participate in receptor signaling by restructuring the membrane cytoskeleton and modulating second messenger generation through the phosphoinositide cycle. We examined these possibilities by overexpressing CapG, an actin filament end capping, Ca(2+)- and polyphosphoinositide-binding protein of the gelsolin family. High level transient overexpression decreased actin filament staining in the center of the cells but not in the cell periphery. Moderate overexpression in clonally selected cell lines did not have a detectible effect on actin filament content or organization. Nevertheless, it promoted a dose-dependent increase in rates of wound healing and chemotaxis. The motile phenotype was similar to that observed with gelsolin overexpression, which in addition to capping, also severs and nucleates actin filaments. CapG overexpressing clones are more responsive to platelet-derived growth factor than control-transfected clones. They form more circular dorsal membrane ruffles, have higher phosphoinositide turnover, inositol 1,4,5-trisphosphate generation and Ca2+ signaling. These responses are consistent with enhanced PLC gamma activity. Direct measurements of PIP2 mass showed that the CapG effect on PLC gamma was not due primarily to an increase in the PIP2 substrate concentration. The observed changes in cell motility and membrane signaling are consistent with the hypothesis that PIP(2)-binding actin regulatory proteins modulate phosphoinositide turnover and second messenger generation in vivo. We infer that CapG and related proteins are poised to coordinate membrane signaling with actin filament dynamics following cell stimulation.

Adaptive watershed segmentation of binary particle image.

Oversegmentation is a tough problem in the morphological watershed segmentation of irregular-shaped binary particles, which is usually caused by spurious minima in the inverse distance transform. The position relationship between two objects is clear, according to the value of overlap parameter defined in the paper, and an adaptive algorithm is presented to depress oversegmentation by building the criterion to merge the spurious local minima. Some particle images are provided to validate the performance of the proposed method.

Identification of messenger RNA substrates for mouse T-STAR.

Using the method of isolation of specific nucleic acids associated with proteins (SNAAP), we have identified 10 candidate target mRNA substrates bound by mT-STAR (mouse T-STAR protein) from testis extract. Among them, our study focused on Fabp9, a gene that is essential for male gametogenesis, and showed that mT-STAR could directly bind to Fabp9 mRNAs. The binding sites are in a short sequence of the coding region and 3' untranslated region of Fabp9 mRNA. These suggest that mT-STAR can regulate the metabolism and expression of Fabp9. In conclusion, identification of mT-STAR-bound mRNA substrates might help to illustrate the potential spectrum of the process and provide valuable insight into the biological function of this RNA-binding protein in spermatogenesis.

[Three-dimensional finite element analysis of the stress distribution of bone tissue around porous titanium implant].

Objective: To analyze the stress distribution of different types of bone tissue around porous titanium implant in different mechanical loads and to further evaluate the biomechanical properties of porous titanium implant. Methods: Finite element (FE) models of implant restorations for the maxillary first premolar was established, and the diameter of implants in the models was 4.1 mm. Five models was constructed according to diameter of implant central pillar and the thickness of outer porosity: solid group (group A), central pillar 1.5 and 3.1 mm and outer porosity 30% (group B and C), central pillar 1.5 and 3.1 mm and outer porosity 40% (group D and E). Different loads (150 N vertical force, 50 N lateral force) were applied to the occlusal surface of implant restorations in type Ⅲ bone and maximal von Mises stress was evaluated. Meanwhile, a couple of simplified maxillary part models varied in four types of bone were constructed with the implants bearing load of simulation ultimate force to evaluate the stress distribution of different types of bone. Results: With different mechanical loading, the stress value of bone tissue around porous implant (group B-E) was greater than that in the solid structure (group A). Under the load of simulation ultimate force, the maximum stress of the bone rised with the increase of porosity and thickness of the porous implant. And the maximum stress value of the surrounding bone tissue changed with the change of bone. Under vertical loading, the maximal von Mises stress of the bone around solid implants of group A was 17.56 MPa, which was a little lower than that of group B and C. And the maximal equivalent von Mises stress of group D and E was 69.24 MPa. The results of lateral force and simulation ultimate force loading were similar. The stress of the bone tissue around implant increased with the decrease of bone quality. The maximum stress value of group D implant was 134.95 MPa. Conclusions: Porous structure of the implant is conducive to transmit stress to surrounding bone tissue and increases the mechanical stimulation of bone. However, if the value and direction of load are inappropriate or quality of bone is poor, pathological stress may be produced.