Intracellular Nitroreductase-Triggered "On" and "Enhanced" Photoacoustic Signals for Sensitive Imaging of Tumor Hypoxia

Current molecular photoacoustic (PA) probes are designed with either stimulus-turned "on" or assembly-enhanced signals to trace biological analytes/events. PA probes based on the nature-derived click reaction between 2-cyano-6-aminobenzothiazole (CBT) and cysteine (Cys) (i.e., CBT-Cys click reaction) possess both "turn-on" and "enhanced" PA signals; and thus, should have higher sensitivity. Nevertheless, such PA probes, particularly those for sensitive imaging of tumor hypoxia, remain scarce. Herein, a PA probe NI-Cys(StBu)-Dap(IR780)-CBT (NI-C-CBT) is rationally designed, which after being internalized by hypoxic tumor cells, is cleaved by nitroreductase under the reduction condition to yield cyclic dimer C-CBT-Dimer to turn the PA signal "ON" and subsequently assembled into nanoparticles C-CBT-NPs with additionally enhanced PA signal ("Enhanced"). NI-C-CBT exhibits 1.7-fold "ON" and 3.2-fold overall "Enhanced" PA signals in vitro. Moreover, it provides 1.9-fold and 2.8-fold overall enhanced PA signals for tumor hypoxia imaging in HeLa cells and HeLa tumor-bearing mice, respectively. This strategy is expected to be widely applied to design more "smart" PA probes for sensitive imaging of important biological events in vivo in near future.

Enhanced Photoacoustic Imaging of Urokinase-Type Plasminogen Activator Activity in Tumors

Photoacoustic (PA) imaging of urokinase-type plasminogen activator (uPA) activity in vivo holds high promise for early diagnosis of breast cancer. Molecular probes with resisted fluorescence (FL) emission for enhanced PA signals of uPA activity have not been reported. Herein, we proposed a molecular probe Cbz-Gly-Gly-Arg-Phe-Phe-IR775 (Z-GGRFF-IR775) which, upon uPA cleavage, assembled into nanoparticles FF-IR775-NP with quenched fluorescence but enhanced PA signals. Experimental results validated that, upon uPA activation, Z-GGRFF-IR775 exhibited 4.7-fold, 4.1-fold, and 2.9-fold higher PA signals over those in uPA inhibitor-treated control groups in vitro, in MDA-MB-231 cells, and in a tumor-bearing mouse model, respectively. We anticipate that this probe could be applied for highly sensitive PA imaging of uPA activity in early stage malignant tumors in the near future.

Enzymatic Self-Assembly of Adamantane-Peptide Conjugate for Combating Staphylococcus aureus Infection

Staphylococcus aureus (S. aureus) remains a leading cause of bacterial infections. However, eradication of S. aureus infections with common antibiotics is increasingly difficult due to outbreaks of drug resistance. Therefore, new antibiotic classes and antibacterial strategies are urgently in demand. Herein, it is shown that an adamantane-peptide conjugate, upon dephosphorylation by alkaline phosphatase (ALP) constitutively expressed on S. aureus, generates fibrous assemblies in situ to combat S. aureus infection. By attaching adamantane to a phosphorylated tetrapeptide Nap-Phe-Phe-Lys-Tyr(H2 PO3 )-OH, the rationally designed adamantane-peptide conjugate Nap-Phe-Phe-Lys(Ada)-Tyr(H2 PO3 )-OH (Nap-FYp-Ada) is obtained. Upon bacterial ALP activation, Nap-FYp-Ada is dephosphorylated and self-assembles into nanofibers on the surface of S. aureus. As revealed by cell assays, the assemblies of adamantane-peptide conjugates interact with cell lipid membrane and thereby disrupt membrane integrity to kill S. aureus. Animal experiments further demonstrate the excellent potential of Nap-FYp-Ada in the treatment of S. aureus infection in vivo. This work provides an alternative approach to design antimicrobial agents.

Caspase-3-Triggered Intracellular Gadolinium Nanoparticle Formation for T1-Weighted Magnetic Resonance Imaging of Apoptosis In Vivo

Apoptosis, with a hallmark of upregulated protease Caspase-3, has been frequently imaged with various probes to reveal the therapeutic efficiencies of different drugs. However, activatable molecular probes with programmable self-assembling behaviors that enable enhanced T₁-weighted magnetic resonance imaging (MRI) of apoptosis remain scarce. Herein, taking advantage of a CBT-Cys click reaction, we rationally designed a Caspase-3-activatable self-assembling probe Ac-Asp-Glu-Val-Asp-Cys(StBu)-Lys(DOTA(Gd))-CBT (DEVDC_S-Gd-CBT) for apoptosis imaging in vivo. After Caspase-3 cleavage in apoptotic cells, DEVDC_S-Gd-CBT underwent CBT-Cys click reaction to form a cyclic dimer, which self-assembled into Gd nanoparticles. With this probe, enhanced T₁-weighted MR images of apoptosis were achieved at low magnetic fields in vitro, in cis-dichlorodiamineplatinum-induced apoptotic cells and in tail-amputation-simulated apoptotic zebrafish. We anticipate that the smart probe DEVDC_S-Gd-CBT could be applied for T₁-weighted MRI of apoptosis-related diseases in the clinic in the future.

Characterization of the genomic and transcriptional structure of chicken NRG4 gene

Neuregulin 4 (NRG4) is an important adipocytokine, which plays crucial roles in maintaining energy balance, regulating glucose and lipid metabolism, and preventing non-alcoholic fatty liver disease in mammals. At present, the genomic organization, transcript and protein isoforms of human NRG4 gene have been fully explored. Previous studies in our laboratory have shown that the NRG4 gene is expressed in chicken adipose tissue, but the chicken NRG4 (cNRG4) genomic structure, transcript and protein isoforms are still unknown. To this end, in this study, the genomic and transcriptional structure of the cNRG4 gene were systematically investigated using rapid amplification of cDNA ends (RACE) and reverse transcription-polymerase chain reaction (RT-PCR). The results showed that the coding region (CDS) of the cNRG4 gene was small, but it had a very complex transcriptional structure characterized by multiple transcription start sites, alternative splicing, intron retention, cryptic exons, and alternative polyadenylation, thus leading to production of four 5?UTR isoforms (cNRG4 A, cNRG4 B, cNRG4 C, and cNRG4 D) and six 3?UTR isoforms (cNRG4 a, cNRG4 b, cNRG4 c, cNRG4 d, cNRG4 e, and cNRG4 f) of the cNRG4 gene. The cNRG4 gene spanned 21,969 bp of genomic DNA (Chr.10:3,490,314~3,512,282) and consisted of 11 exons and 10 introns. Compared with the cNRG4 gene mRNA sequence (NM_001030544.4), two novel exons and one cryptic exon of the cNRG4 gene were identified in this study. Bioinformatics analysis, RT-PCR, cloning and sequencing analysis showed that the cNRG4 gene could encode three protein isoforms (cNRG4-1, cNRG4-2 and cNRG4-3). This study lays a foundation for further research on the function and regulation of the cNRG4 gene.

[A cross-sectional study of enterovirus nucleic acid test with throat swabs for term late neonates during coronavirus disease 2019]

OBJECTIVES

To investigate the positive rate of enterovirus (EV) nucleic acid in throat swabs of term late neonates hospitalized during the coronavirus disease 2019 (COVID-19) epidemic and the clinical characteristics of the neonates.

METHODS

A single-center cross-sectional study was performed on 611 term late infants who were hospitalized in the neonatal center from October 2020 to September 2021. Throat swabs were collected on admission for coxsackie A16 virus/EV71/EV universal nucleic acid testing. According to the results of EV nucleic acid test, the infants were divided into a positive EV nucleic acid group (8 infants) and a negative EV nucleic acid group (603 infants). Clinical features were compared between the two groups.

RESULTS

Among the 611 neonates, 8 tested positive for EV nucleic acid, with a positive rate of 13.1‰, among whom 7 were admitted from May to October. There was a significant difference in the proportion of infants contacting family members with respiratory infection symptoms before disease onset between the positive and negative EV nucleic acid groups (75.0% vs 10.9%, P<0.001). There were no significant differences between the two groups in demographic data, clinical symptoms, and laboratory test results (P>0.05).

CONCLUSIONS

There is a certain proportion of term late infants testing positive for EV nucleic acid in throat swabs during the COVID-19 epidemic, but the proportion is low. The clinical manifestations and laboratory test results of these infants are non-specific. Transmission among family members might be an important cause of neonatal EV infection.

Enzymatic Nanosphere-to-Nanofiber Transition and Autophagy Inducer Release Promote Tumor Chemotherapy

Chemotherapy has remained an effective and predominant cancer treatment for the past decades, but is hampered by its low response rate and severe systemic toxicity. Combination chemotherapies are proposed to address these issues, yet their therapeutic outcomes are still far from satisfactory. Thus, it is urgent to develop novel strategies to promote tumor chemosensitivity while reducing toxic side effects of chemotherapeutics. Herein, employing a rationally designed peptide conjugate Nap-Phe-Phe-Lys(SA-AZD8055)-Tyr(H₂ PO₃ )-OH (Nap-AZD-Yp), a novel approach of simultaneous intracellular nanofiber formation and autophagy inducer release is proposed for selectively sensitizing tumor to chemotherapy. Upon sequential catalyses of alkaline phosphatase and carboxylesterase, Nap-AZD-Yp undergoes nanosphere-to-nanofiber transition accompanied by autophagy inducer AZD8055 release in cancer cells. Cell experiments show enhanced endocytosis of anticancer drug doxorubicin and inhibition of cell migration due to the intracellular nanofiber formation. The released AZD8055 further activates excessive autophagy of cancer cells, sensitizing them to chemotherapy. Animal experiment results suggest Nap-AZD-Yp can significantly enhance the therapeutic effects of doxorubicin on tumors while mitigate its toxic adverse effects on normal tissues. It is anticipated that the "smart" concept in this work c be widely employed to develop novel combinational therapies for the treatment of cancers and other diseases in near future.

[Analysis of occurrence and treatment of perioperative complete atrioventricular block by transcatheter aortic valve implantation]

Objective: To retrospectively analyze the occurrence and treatment of perioperative complete atrioventricular block (CAVB) by transcatheter aortic valve implantation (TAVI). Methods: A total of 65 patients who underwent TAVI via femoral artery in the Heart Center of Henan People's Hospital from October 2017 to May 2021 were enrolled. Perioperative data of patients were recorded. The patients were divided into two groups according to whether complete atrioventricular block was occurred during TAVI: complete atrioventricular block group (Group CAVB) and non-complete atrioventricular block group (Group NCAVB). Multivariate logistic regression model was used to analyze the risk factors of complete atrioventricular block during transcatheter aortic valve implantation. The incidence of perioperative complications were recorded. Results: The patients age was (69.1±7.3) years old. and there were 35 males and 30 femals. There were 15 patients in group CAVB with complete atrioventricular block and 50 patients in group NCAVB. Multivariate analysis showed that preoperative right bundle branch block [OR (95%CI) vs 3.325 (2.132-13.061), P=0.005] and severe aortic valve calcification [OR (95%CI) vs 1.271 (1.052-3.326), P=0.030] were independent correlative factors for CAVB during TAVI perioperative period. The implantation rate of permanent pacemaker in group CAVB was 73.3% (11 cases), which was higher than 6.0% (3 cases) in group NCAVB (P<0.001). Conclusions: It indicated that preoperative right bundle branch block and severe aortic valve calcification are correlative factors for complete atrioventricular block for TAVI. The implantation rate of permanent pacemaker in complete atrioventricular block group increased significantly.

Glutathione-Depleting Nanomedicines for Synergistic Cancer Therapy

Cancer cells frequently exhibit resistance to various molecular and nanoscale drugs, which inevitably affects the drugs' therapeutic outcomes. Overexpression of glutathione (GSH) has been observed in many cancer cells, and solid evidence has corroborated the resulting tumor resistance to a variety of anticancer therapies, suggesting that this biochemical characteristic of cancer cells can be developed as a potential target for cancer treatments. The single treatment of GSH-depleting agents can potentiate the responses of the cancer cells to different cell death stimuli; therefore, as an adjunctive strategy, GSH depletion is usually combined with mainstream cancer therapies for enhancing the therapeutic outcomes. Propelled by the rapid development of nanotechnology, GSH-depleting agents can be readily constructed into anticancer nanomedicines, which have shown a steep rise over the past decade. Here, we review the common GSH-depleting nanomedicines which have been widely applied in synergistic cancer treatments in recent years. Some current challenges and future perspectives for GSH depletion-based cancer therapies are also presented. With the understanding of the structure-property relationship and action mechanisms of these biomaterials, we hope that the GSH-depleting nanotechnology will be further developed to realize more effective disease treatments and even achieve successful clinical translations.

Large mode area microstructured fiber supporting 56 super-OAM modes

In this paper, a kind of super-mode orbital angular momentum microstructured fiber (SM-OAM-MSF) is proposed. By introducing 20 Ge-doped equiangular cylindrical inclusions in the ring-core region, mode coupling mechanism is employed in the formation of super-OAM (SOAM) modes. Specifically, the double degenerated out-of-phase SMs are first generated by the coupling of individual core mode, then the quadruple degenerated SOAM modes are formed by combining two components of the out-of-phase SMs with a phase difference of ±π/2. Theoretical analysis and numerical results reveal that the effective index difference (Δn_eff) between adjacent out-of-phase SM groups are strongly influenced by the parameters of the individual core except the ring-core's width. Therefore, large mode area and SOAM modes' index separation larger than 1.0×10^-4 can be achieved simultaneously in our proposed SM-OAM-MSF. Through careful fiber design, HE_1,1 and HE_2,1 are used in the formation of SMs and SOAM modes. Simulations show that all the nine SOAM groups originating from HE_1,1 mode and the first five SOAM groups stemming from normal coupling of HE_2,1 mode can be supported above 1.0µm, that are 56 SOAM modes in total. The highest purity is 99.86% for SOAM±2,1±,5 mode. And the maximum mode area (A_eff) value reaches up to 638.88µm² at 1.55µm, which is nearly eight times larger compared to that of conventional ring-core MSFs.

Association Between MTHFR Genetic Polymorphism and Parkinson's Disease Susceptibility: A Meta-analysis

Folate metabolism plays quite a critical role in Parkinson’s disease (PD). Previous published research works have studied the link existing between the folate metabolism genetic polymorphisms and PD susceptibility; nevertheless, the results continue having controversies and inconclusiveness. Accordingly, we carried out the present meta-analysis for the assessment of the potential link between the folate metabolism genetic polymorphisms and the susceptibility to PD. In addition we carried out a literature search in the PubMed, EMBASE, Cochrane Library, and WanFang databases till November 10, 2018. The odds ratios (ORs) with corresponding 95% credible interval (95%CI) were put to use for evaluating the strength of the association of three folate metabolism genetic polymorphism ( C677T, A1298C, and A2756G) with the susceptibility to PD. Each statistical analysis was carried out with the use of STATA 15.0. An aggregate of twenty-one case-control investigations were retrieved, which involved 3,944 PD patients and 4,412 controls. We discovered the existence of no substantial link between the C677T and A1298C polymorphism and PD risk in any genetic framework comparisons. With regard to A2756G polymorphism, we discovered that there was an association between the A2756G genetic polymorphism and an augmented threat of PD in the co-dominant genetic framework (GG vs. AA: OR=1.86, 95%CI=1.02-3.37, P=0.042) and the recessive genetic model (GG vs. GA+AA: OR=1.90, 95%CI=1.06-3.41, P=0.031). To summarize, our research work indicates that the A2756G polymorphism of the folate metabolism gene had an association with an augmented threat of PD. Also, A1298C polymorphisms is unlikely to significantly contribute towards the susceptibility to PD. Further large-scale case-control studies are still required.

Evaluation of the efficacy of neoadjuvant chemotherapy for breast cancer using diffusion-weighted imaging and dynamic contrast-enhanced magnetic resonance imaging

This study aims to investigate the predictive values of diffusion-weighted imaging (DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in evaluating the efficacy of neoadjuvant chemotherapy (NAC) for breast cancer. Between September 2011 and December 2014, a total of 174 patients with locally advanced breast cancer treated with NAC were selected for this study. Conventional CT and MRI examinations (DWI and DCE-MRI) were performed in all patients before NAC (T0), after the first course (T1) and after the whole course (T2) of NAC. According to the response evaluation criteria in solid tumors (RECIST), patients were divided into the effective [complete response (CR) + partial response (PR)] and ineffective groups [stable disease (SD) + disease progression (DP)]. The Apparent diffusion coefficient (ADC), maximum tumor diameter, the early-phase enhancement rate (Ee), maximal enhanced rate of tumor (E max), maximal linear slope (S max), maximal excretion rate (E wash), signal intensity (SI), maximal signal rise velocity (V max) and area under the curve (AUC) of Cho before and after NAC were calculated. Receiver operating characteristic (ROC) curve was drawn and the AUC of change rate of ADC values and semi-quantitative parameter were utilized to analyze the diagnostic performance of them for evaluating the efficacy of NAC for breast cancer. There were 135 patients in the effective group, with 52 cases of CR and 83 cases of PR; 39 patients were in the ineffective group, with 14 cases of PD and 25 cases of SD. The effective rate of NAC for breast cancer was 77.6%. The ADC values of the two groups significantly increased but the maximum tumor diameter, E e, E max, S max, E wash and AUC of Cho greatly decreased. The effective group had higher ADC values, its change rate and tumor regression rate than the ineffective group. However, the maximum tumor diameter, E e, E max, S max, E wash, AUC of Cho, SI and V max in the effective group were remarkably lower than those in the ineffective group. The change rate of ADC mean achieved the highest evaluation efficiency with AUC of 0.920, sensitivity of 80.0% and specificity of 94.9%. The optimal critical value was 36.49 (× 10-3mm2/s). In conclusion, these results demonstrated that the change rate of ADC mean values and E e could be promising tools for evaluating the efficacy of NAC in patients with breast cancer.

[In vivo characteristics of spinal kinematics in senile degenerative lumbar spondylolysis]

Objective: To investigate the in vivo kinematics of the lumbar degenerative spondylolysis (LDS) in senile patients. Methods: From March to October in 2014, nine L(4-5) LDS patients [mean age (74±9) years] and nine healthy volunteers [mean age, (54±4) years] were recruited. Combined fluoroscopy and CT scanning technique were used to obtain the three dimension kinematic data of the vertebral anatomical structures (vertebral body anterior margin, vertebral body posterior margin, facet joints and spinous process) in various postures (supine, standing, flexion and extension) under physical loads, and to compare the stability of different anatomical structures. The L(4-5) segmental disc angle was also measured in different postures. Paired-samples t test was applied to compare the displacement differences between the two groups. Results: During flexion-extension motion, all anatomical structures of the LDS group were slightly larger than those in normal group, but the statistical difference was not obvious (all P>0.05). For normal group, in anterior-posterior and cranial-caudal direction, sub-movement analysis showed that the anterior vertebral body margin at the flexion range of motion [(-1.07±0.84) mm, (-1.27±1.01) mm] were larger than the extension range of motion [(0.66±1.38) mm, (0.63±0.99) mm] (t=3.21, 4.03, both P<0.05). Whereas for LDS group, in anterior-posterior and cranial-caudal direction, sub-movement analysis showed that the anterior vertebral body margin at the extension range of motion [(1.46±1.26) mm, (1.17±0.54) mm] were significantly greater than the flexion range of motion [(-0.43±0.47) mm, (-0.45±1.24) mm] (t=4.22, 3.59, both P<0.05). The disc angles of the LDS group were all smaller than those in normal group, but the statistical difference was not obvious (all P>0.05). However, the disc angles were significantly different under different postures, the flexion were both the smallest in the normal group and LDS group. Conclusions: The senile LDS patients may not necessarily have instability, stability may also occur in these patients. Increasing extension range of motion is one of the kinematic characteristics in senile patients with LDS. The intervertebral stability should be taken into account, but if instability develops, surgical procedure should be suggested for elderly patients with LDS.

Electronic structure of multiferroic BiFeO3: Electron energy-loss spectroscopy and first-principles study

The electronic structure of BiFeO₃ has been investigated by using electron energy loss spectrum and first-principle calculations. Assignments of the individual interband transitions have been accomplished by comparing the interband transition energy with the calculated PDOS. The DOS is mainly divided into two regions, the hybridized region of O 2p with Fe 3p in the valence band and that of O 2p hybridized with Bi 6p in the conduction band. From the simulation of high energy-loss near-edge structure, the core-hole effect is believed to be more significant. The feature groups for the experimental spectra of O K-edge and Fe L_2,3-edge are consistent with simulation results.

Chicken GHR antisense transcript regulates its sense transcript in hepatocytes

An increasing number of evidences indicated that long noncoding RNAs (LncRNAs) regulate a variety of biological progresses via different mechanisms. Our previous study had identified a chicken growth hormone receptor (GHR) antisense transcript (GHR-AS) which regulated GHR sense transcript (GHR-S) in LMH cells. In the present study, roles of GHR-AS and its regulatory mechanism were analyzed in chicken hepatocytes. The expression patterns of liver GHR-S, GHR-AS and Let-7b ascended with the development of chicken. The hepatocytes proliferation was promoted and more cells entered into DNA synthesis (S) phase when GHR-AS was overexpressed while the cell proliferation was slowed and fewer cells were in S phase when GHR-AS was interfered. Meanwhile, the GHR-S increased when we overexpressed GHR-AS while it reduced when GHR-AS was inhibited. The S1 Nuclease protection assay indicated that GHR-S and GHR-AS formed RNA duplex via GHR-S 3' untranslation regon (3'UTR). In hepatocytes or LMH cells, the half-time of GHR-S showed a delayed trend when GHR-AS or GHR-AS 5' untranslation regon (5'UTR) was overexpressed. Furthermore, the level of GHR-S can be decreased by Let-7b mimics whereas it was partially rescued when co-transfected pGHR-AS or pGHR-AS 5'UTR with Let-7b mimics. Based on our findings, GHR-AS affected hepatocytes proliferation and improved GHR-S stability possibly by forming RNA duplex between GHR-S and GHR-AS, competing with Let-7b.

A genetics laboratory class to analyze early and late feather traits of chicken

With the implementation of the "Education and Training Program for Outstanding Agricultural and Forestry Talents" in our country, our university established the "Outstanding Class" for students majoring in the animal science. We also carried out a series of educational management and curriculum reforms to cultivate students' systematic model of thinking and the ability of technology innovation. In this paper, we designed a comprehensive experiment that focused on analyzing early and late feather genetic traits of chicken. The students initially observed the phenotype of chickens and gradually were led into genetics analysis. We introduced the breeding practice, and guided the students to use genetic theories to breed chick strains of early and late feather traits. The experiment is not only based on the sex-linkage theory and sex determination mechanism, but also molecular genetics technologies, such as genomic DNA extraction, amplification, enzyme digestion and electrophoresis. Conducting this experiment can enhance students' comprehensive analysis ability and professional skills, as well as be beneficial to cultivate their scientific research interests and curiosity on animal sciences. Thus, we integrated the genetics theories into animal breeding practice that meet the requirement of comprehensive applied talents of animal science specialty. The teaching ideas and methods described in this paper can be applied to other biological experiment teaching practice.

[Effect of miR-19b on the proliferation and apoptosis of P19CL6 cells during the late-stage of cardiac differentiation]

Objective: To explore the effect of miR-19b on the function of P19CL6 cells and its molecular mechanism. Methods: Overexpression of miR-19b was carried out by transfecting miR-19b plasmid into the P19CL6 cells. MTT assay and flow cytometry were used to determine cell growth and apoptosis, respectively. Western blot was used to detect the expression level of Sox6 in P19CL6 cells. ELISA assay was used to detect the expression levels of apoptosis-related genes (Bax, Bcl-2) in P19CL6 cells at late-stage cardiac differentiation. Further online software TargetScan was used to predict the target genes of miR-19b and verified by dual luciferase reporter assay. Results: Our data showed that overexpression of miR-19b in P19CL6 cells significantly increased the cell growth rates and the apoptosis inhibition rates. The ratio of apoptosis-related proteins (Bax/Bcl-2) was significantly reduced. Results from the TargetScan and dual luciferase reporter showed that Sox6 is the direct target of miR-19b. Conclusions: We conclude that miR-19b might promote cell proliferation and inhibits cell apoptosis during the late-stage of cardiac differentiation by targeting Sox6 expression.

[Evaluation of health effect among occupational population exposed to nano-titanium dioxide: a cross-sectional study]

Objective: To characterize the health effects of nano-titanium dioxide exposure in an occupational cohort. Methods: Eighty-five male employees of a nano-titanium dioxide manufacturing enterprise in Shandong Province were evaluated in September 2014. Forty-four were exposed to nano-titanium dioxide (exposure group), and 41 were not exposed to nano-titanium dioxide (control group). We collected employees' basic information, smoking and drinking history, previous medical history, family history, and occupational history. Differences in blood pressure, hematological parameters, and blood biochemistry between the two groups were analyzed and compared. Multiple linear regression analysis was used to investigate the effect of nano-titanium dioxide exposure on blood pressure, hematological parameters, and blood biochemistry indices after controlling for age, smoking, drinking, and body mass index (BMI). Twenty-five employees from the exposure group and 25 employees from the control group were selected at random for measurement of genetic damage by cytokinesis-block micronucleus assay. Poisson regression analysis was used to investigate the effect of nano-titanium dioxide exposure on micronucleus frequency or micronucleus cell frequency after controlling for age, smoking, drinking, and BMI. Results: The median (P₂₅-P₇₅) surface area concentration of particles deposited in the tracheobronchial region, the surface area concentration of particles deposited in the alveolar region, and particle number concentration in the exposure group were 35.35(24.31-57.42) μ m²/cm³, 173.09(116.27-270.72) μ m²/cm³, and 40 244.00 (17 803.50-78 679.00) /cm³, respectively. These values were significantly higher than those in the control group 33.90 (27.44-43.29) μm²/cm³, 150.50(125.82-192.87)μm²/cm³, and 18 721.00 (12 721.00-51 898.50)/cm³, respectively. Z values were 15.47, 15.96, and 14.54, respectively (P<0.001 for all three values). Multiple linear regression analysis showed that exposure to nano-titanium dioxide contributed most to the alteration of mean corpuscular hemoglobin concentration, creatinine, and LDL-C, with standardized regression coefficients of 0.23, -0.51, and 0.30, respectively (P<0.05 for all three values), after adjusting for age, smoking, drinking, and BMI. There were no significant differences in micronucleus frequency and micronucleus cell frequency between the exposure group (3.00‰ (1.50‰-5.00‰) and 3.00‰ (2.00‰-4.00‰), respectively) and control group (2.00‰ (1.00‰-4.50‰) and 2.00‰ (1.00‰-4.00‰), respectively); P>0.05 for all comparisons. Poisson regression analysis showed that after adjusting for age, smoking, drinking, and BMI, there was still no statistically significant correlation between nano-titanium dioxide exposure and micronucleus frequency (OR=1.11, 95% CI: 0.81-1.54) or micronucleus cell frequency (OR=1.07, 95% CI: 0.75-1.51); P>0.05 for all comparisons. Conclusion: Nano-titanium dioxide particles exerted some health effects on the occupationally-exposed cohort, whose hematological parameters and blood biochemistry were influenced to some degree. However, a potential link between occupational exposure to nano-titanium dioxide and blood pressure or induction of genetic damage or was not found.

[Application of three control banding tools to occupational health risk assessment of titanium dioxide manufacturing factory]

Objective: To explore and validate suitable risk assessment methods for titanium dioxide though applying three risk assessment tools for nanomaterials based on the control banding (CB) approach. Methods: A factory manufacturing titanium dioxide in Jinan city, Shandong province, was assessed using a quantitative exposure method and qualitative risk assessment methods in September, 2014. A condensation particle counter equipment was used to monitor the number concentration of particles at packaging workshop and jet milling workshop. We employed three control banding tools, including CB nanotool, Stoffenmanager nano and the Guidance on working safely with nanomaterials and nanoproducts (GWSNN) to evaluate the two workshops, then compared the evaluation results. Results: The increases of particle concentrations were generated directly by packaging and jet milling processes, the number concentration from (3.52±1.46) ×10(4)/cm(3) to (14.70±8.86) ×10(4)/cm(3) at packaging workshop and from (0.97±0.25) ×10(4)/cm(3) to (1.26±0.35) ×10(4)/cm(3) at milling workshop (both P<0.05) . The number concentrations at packaging workshop were higher than those at jet milling workshop during both manufacturing and break times (both P<0.05) . The results of CB nanotool showed that the risk level of the packaging workshop was classified as high and the risk level of the jet milling workshop was classified asmedium. The results of Stoffenmanager nano showed that the risk level of the packaging workshop was classified as medium and the risk level of the jet milling workshop was classified as low. The results of GWSNN showed that the risk level of packaging workshop was classified as high and the risk level of jet milling workshop was classified as low. Conclusion: The results of evaluation based on the three control banding tools are related and aligned with the results of quantitative monitoring, so they are all suitable to perform occupational health risk assessment on industrial scale production of titanium dioxideto some extent.

Effects of Astragalus Polysaccharides and Astragalosides on the Phagocytosis of Mycobacterium tuberculosis by Macrophages

The herb Astragalus membranaceus is used in traditional Chinese medicine to boost immunity. This study investigated the effects of Astragalus polysaccharides (APS) and astragalosides (AS) on the phagocytosis of Mycobacterium tuberculosis by macrophages. Peritoneal macrophages were obtained by peritoneal lavage from mice stimulated by starch gravy culture medium and cultured with M. tuberculosis and varying concentrations of APS and AS. Phagocytotic activity was measured using a real-time polymerase chain reaction assay to detect M. tuberculosis DNA. Levels of interleukin-1β, interleukin-6 and tumour necrosis factor-α secreted by activated macrophages in the culture supernatant were determined using an enzyme-linked immunosorbent assay. Macrophage phagocytotic activity and secreted cytokine levels were significantly increased after treatment with APS and AS. This study provides evidence that APS and AS have strong promoting effects on the phagocytosis of M. tuberculosis by macrophages and the secretion of interleukin-1β, interleukin-6 and tumour necrosis factor-α by activated macrophages.

[Feasibility of retrograde approach for percutaneous closure of ventricular septal defect under solely guidance of transesophageal echocardiography]

OBJECTIVE

To evaluate the feasibility of retrograde transcatheter closure of ventricular septal defects (VSD) under trans-esophageal echocardiography (TEE).

METHODS

Twelve patients with VSD, with 4 residual shunt, treated by transcatheter VSD closure under solely guidance of TEE were summarized. Mean age, body weight and average diameter of VSD in 12 cases were (11.58±6.57) years, (31.85±13.28) kg, (5.50±2.20) mm, respectively. All patients were treated by retrograde transcatheter closure under solely guidance of TEE. The post-operative efficiency was estimated by TEE immediately. Patients were followed up by echocardiography, X-ray examination and electrocardiogram at 24 hours, 1, 3 and 6 months after the procedures.

RESULTS

All 12 patients were treated successfully under solely guidance of TEE. The diameter of devices were 5-14 mm. There were 1 case with trivial residual shunt after the procedures immediately. No patients suffered from residual shunt, occluder malposition, peripheral vascular injury and pericardial effusion during the follow-up.

CONCLUSION

Percutaneous transcatheter closure of VSD completely guided by TEE is safe and effective. This method could avoid the radiation and contrast media reaction, and also could simplify the procedure.

Linoleic acid induces red blood cells and hemoglobin damage via oxidative mechanism

Hidden blood loss typically occurs following total hip arthroplasty (THA) and total knee arthroplasty (TKA) and is thought to be related to free fatty acid (FFA). To study the effect of linoleic acid on red blood cells and to examine the pathogenesis of hidden blood loss in vivo, we generated an animal model by injecting linoleic acid into the tail veins of rats. We collected blood samples and determined red blood cell count (RBC) and levels of hemoglobin (Hb), as well as the oxidation and reducing agents in the blood, including glutathione peroxidase (GSH-PX), total superoxide dismutase (T-SOD), hydrogen peroxide (H2O2), and ferryl hemoglobin (Fe4+=O2-), which is generated by the oxidation of Hb. Hidden blood loss occurred when linoleic acid was administered at a concentration of 60 mmol/L; RBC and Hb levels were significantly reduced by 24 h post-injection. This was followed by erythrocyte deformation, reduced activity of GSH-PX and T-SOD, and decreased levels of H2O2. This was accompanied by an increase in ferryl species, which likely contributes to oxidative stress in vivo. Our findings suggest that linoleic acid enhances acute red blood cell injury. Hb and RBC began to increase by 72 h, potentially resulting from linoleic acid metabolism. Thus, elevated levels of linoleic acid in the blood cause acute oxidative damage to red blood cells, eventually leading to partial acute anemia. These findings highlight the pathophysiology underlying hidden blood loss.

Identification of mud crab reovirus VP12 and its interaction with the voltage-dependent anion-selective channel protein of mud crab Scylla paramamosain

Mud crab reovirus (MCRV) is the causative agent of a severe disease in cultured mud crab (Scylla paramamosain), which has caused huge economic losses in China. MCRV is a double-stranded RNA virus with 12 genomic segments. In this paper, SDS-PAGE, mass spectrometry and Western blot analyses revealed that the VP12 protein encoded by S12 gene is a structural protein of MCRV. Immune electron microscopy assay indicated that MCRV VP12 is a component of MCRV outer shell capsid. Yeast two hybrid cDNA library of mud crab was constructed and mud crab voltage-dependent anion-selective channel (mcVDAC) was obtained by MCRV VP12 screening. The full length of mcVDAC was 1180 bp with an open reading frame (ORF) of 849 bp encoding a 282 amino acid protein. The mcVDAC had a constitutive expression pattern in different tissues of mud crab. The interaction between MCRV VP12 and mcVDAC was determined by co-immunoprecipitation assay. The results of this study have provided an insight on the mechanisms of MCRV infection and the interactions between the virus and mud crab.

Anterior cervical discectomy and fusion versus anterior cervical corpectomy and fusion in the treatment of multilevel cervical spondylotic myelopathy: systematic review and a meta-analysis

BACKGROUND

To date, the decision to treat multilevel cervical spondylotic myelopathy (CSM) with anterior cervical discectomy and fusion (ACDF) or anterior cervical corpectomy and fusion (ACCF) remains controversial. Therefore, we conducted a meta-analysis to quantitatively determine the efficacy of ACDF and ACCF in the treatment of multilevel CSM.

METHODS

We searched several databases for related research articles published in English or Chinese. We extracted and assessed the data independently. We determined the pooled data, data heterogeneity, and overall effect, respectively.

RESULTS

We identified 15 eligible studies with 1,368 patients. We found that blood loss and numbers of complications during surgery in ACDF were significantly less that in ACCF; however, other clinical outcomes, such as operation time, bone fusion failure, post Japanese Orthopedic Association scores, recovery rates, and visual analog scale scores between ACDF and ACCF with multilevel CSM were not significantly different.

CONCLUSION

Our results strongly suggest that surgical treatments of multilevel CSM are similar in terms of most clinical outcomes using ACDF or ACCF.

Effect of cocaine on ion channels and glutamatergic EPSCs in noradrenergic locus coeruleus neurons

The locus coeruleus (LC) is an important brainstem area involved in cocaine addiction. However, evidence to elucidate how cocaine modulates the activity of LC neurons remains incomplete. Here, we performed whole recordings in brain slices to evaluate the effects of cocaine on the sodium (Na(+)), potassium (K(+)), calcium (Ca(2+)) channels, and glutamatergic synaptic transmission in the locus coeruleus neurons. Local application of cocaine significantly and reversibly reduced the spontaneous firing rate but did not affect action potential amplitude, rising time, decay time, or half width of noradrenergic locus coeruleus neurons. Moreover, cocaine attenuated the sodium current but did not affect potassium and calcium currents. The N-methyl-D-aspartate receptor mediated excitatory postsynaptic currents were reduced by neuropeptide galanin but not cocaine. All those data demonstrate that cocaine has inhibitory effect on the spontaneous activities and sodium current in locus coeruleus neurons. Therefore, neuromodulation of sodium channel in locus coeruleus neurons may play an important role in drug addiction.

[Penile erectile function after lumbar discectomy for intervertebral disc herniation in different age groups of male patients]

OBJECTIVE

To investigate the treatment effect on penile erectile function after lumbar discectomy in different age groups of men.

METHODS

We included in this study 90 male patients with intervertebral disc herniation treated by lumbar discectomy, who were divided into three age groups of equal number: groups A (< 45 yr), B (45 - 55 yr) and C ( > 55 yr). We obtained the IIEF-5 scores of the patients preoperatively and at 12 months after surgery.

RESULTS

The IIEF-5 scores at 12 months after surgery were 21.3 +/- 3.3, 16.8 +/- 1.3 and 14.1 +/- 1.0 in groups A, B and C, respectively, significantly higher than 10.4 +/- 2.6, 10.7 +/- 2.8 and 11.2 +/- 1.9 preoperatively (P < 0.05). Group A showed better improved erectile function than B and C ([51.17 +/- 6.25 ]% vs [36.31 +/- 4.28]% and [22.71 +/- 5.68]%, P < 0.05).

CONCLUSION

Penile erectile function of the male patient is one of the major factors in evaluating lumbar discectomy for intervertebral disc herniation. Early decompression surgery according to different etiological factors is very important for erectile function recovery in the young and middle-aged male patients.

The pro-survival role of autophagy depends on Bcl-2 under nutrition stress conditions

Autophagy can be induced under nutrition stress conditions. Bcl-2 is a pro-survival protein which inhibits apoptosis and autophagy. However, the role of Bcl-2 in autophagy regulation and cell survival under nutrition deprivation has not been fully understood. This study sought to investigate if Bcl-2 upregulation is essential in limiting autophagic activity and prevent cell death under nutrition deprivation conditions. Autophagic activity was monitored by the changes in GFP-LC3 localization and protein levels of Beclin1, LC3-II, cathepsin D and p62 in neuroblastoma SH-SY5Y cells underwent serum deprivation. Manipulation of Bcl-2 function was achieved with siRNAs and small molecular inhibitors. The cell viability and apoptosis were assessed with MTT assay and Annexin V/PI staining. The results showed that serum starvation increased protein levels of LC3-II and Beclin1 but decreased autophagy substrate p62. Autophagy activation induced by serum deprivation and rapamycin was accompanied by an upregulation of Bcl-2 protein levels. When Bcl-2 was knocked down with siRNA or inhibited with HA 14-1 or ABT-737, serum starvation induced profound cell death and enhanced autophagic flux under nutrition deprivation conditions, while knockdown of autophagic gene Beclin1 or autophagy inhibitors (bafilomycin A1 and E64D), rescued cell death. In contrast, overexpression of Bcl-2 inhibited autophagy and blocked cell death in response to serum deprivation. These data suggest that Bcl-2 plays an essential role in limiting autophagy activation and preventing initiation of programmed cell death. Thus Bcl-2 may be an important mechanism for balancing beneficial and detrimental impacts of autophagy on cell survival.

Pathogenicity and complete genome sequence analysis of the mud crab dicistrovirus-1

A virus with a particle diameter of approximately 30 nm and no envelope was purified from diseased mud crab, Scylla paramamosain and it was demonstrated to be pathogenic to mud crab. The complete nucleotide sequence analysis indicated that its genome was a single molecule of linear positive-sense ssRNA with a length of 10,415 nucleotides, excluding the 3'poly (A) tail. It consisted of two open reading frames (ORF) separated by an intergenic region (IGR) and flanked by a 5'untranslated region (5'-UTR) and a 3'untranslated region (3'-UTR). The 5'-ORF encode five putative non-structural proteins, including BIR (Baculovirus Inhibitor of Apoptosis Protein Repeat), helicase, VPg (the genome-linked viral protein), 3C-like protease and RdRP (RNA-dependent RNA polymerase), while the 3'-ORF encode the structural protein precursors. This genome organization was consistent with the typical organization of dicistrovirus and the virus was designated as mud crab dicistrovirus-1 (MCDV-1). The results of the phylogenetic analysis of the putative structural protein precursor suggest that MCDV-1 has a closer genetic relationship with Taura syndrome virus (TSV) than do other dicistroviruses and that MCDV-1 is a new member of the family Dicistroviridae and assigned into the genus Aparavirus.

A potential oncogenic role of the commonly observed E2F5 overexpression in hepatocellular carcinoma

AIM: To explore the expression pattern of E2F5 in primary hepatocellular carcinomas (HCCs) and elucidate the roles of E2F5 in hepatocarcinogenesis.

METHODS: E2F5 expression was analyzed in 120 primary HCCs and 29 normal liver tissues by immunohistochemistry analysis. E2F5-small interfering RNA was transfected into HepG2, an E2F5-overexpressed HCC cell line. After E2F5 knockdown, cell growth capacity and migrating potential were examined.

RESULTS: E2F5 was significantly overexpressed in primary HCCs compared with normal liver tissues (P = 0.008). The E2F5-silenced cells showed significantly reduced proliferation (P = 0.004). On the colony formation and soft agar assays, the number of colonies was significantly reduced in E2F5-silenced cells (P = 0.004 and P = 0.009, respectively). E2F5 knockdown resulted in the accumulation of G0/G1 phase cells and a reduction of S phase cells. The number of migrating/invading cells was also reduced after E2F5 knockdown (P = 0.021).

CONCLUSION: To our knowledge, this is the first evidence that E2F5 is commonly overexpressed in primary HCC and that E2F5 knockdown significantly repressed the growth of HCC cells.

Tropomyosin3 overexpression and a potential link to epithelial-mesenchymal transition in human hepatocellular carcinoma

Background

Since hepatocellular carcinoma (HCC) is one of the leading causes of cancer death worldwide, it is still important to understand hepatocarcinogenesis mechanisms and identify effective markers for tumor progression to improve prognosis. Amplification and overexpression of Tropomyosin3 (TPM3) are frequently observed in HCC, but its biological meanings have not been properly defined. In this study, we aimed to elucidate the roles of TPM3 and related molecular mechanisms.

Methods

TPM3-siRNA was transfected into 2 HCC cell lines, HepG2 and SNU-475, which had shown overexpression of TPM3. Knockdown of TPM3 was verified by real-time qRT-PCR and western blotting targeting TPM3. Migration and invasion potentials were examined using transwell membrane assays. Cell growth capacity was examined by colony formation and soft agar assays.

Results

Silencing TPM3 resulted in significant suppression of migration and invasion capacities in both HCC cell lines. To elucidate the mechanisms behind suppressed migration and invasiveness, we examined expression levels of Snail and E-cadherin known to be related to epithelial-mesenchymal transition (EMT) after TPM3 knockdown. In the TPM3 knockdown cells, E-cadherin expression was significantly upregulated and Snail downregulated compared with negative control. TPM3 knockdown also inhibited colony formation and anchorage independent growth of HCC cells.

Conclusions

Based on our findings, we formulate a hypothesis that overexpression of TPM3 activates Snail mediated EMT, which will repress E-cadherin expression and that it confers migration or invasion potentials to HCC cells during hepatocarcinogenesis. To our knowledge, this is the first evidence that TPM3 gets involved in migration and invasion of HCCs by modifying EMT pathway.

Clinical implication of recurrent copy number alterations in hepatocellular carcinoma and putative oncogenes in recurrent gains on 1q

To elucidate the pathogenesis of hepatocellular carcinoma (HCC) and develop useful prognosis predictors, it is necessary to identify biologically relevant genomic alterations in HCC. In our study, we defined recurrently altered regions (RARs) common to many cases of HCCs, which may contain tumor-related genes, using whole-genome array-CGH and explored their associations with the clinicopathologic features. Gene set enrichment analysis was performed to investigate functional implication of RARs. On an average, 23.1% of the total probes were altered per case. Mean numbers of altered probes are significantly higher in high-grade, bigger and microvascular invasion (MVI) positive tumors. In total, 32 RARs (14 gains and 18 losses) were defined and 4 most frequent RARs are gains in 1q21.1-q32.1 (64.5%), 1q32.1-q44 (59.2%), 8q11.21-q24.3 (48.7%) and a loss in 17p13.3-p12 (51.3%). Through focusing on RARs, we identified genes and functional pathways likely to be involved in hepatocarcinogenesis. Among genes in the recurrently gained regions on 1q, expression of KIF14 and TPM3 was significantly increased, suggesting their oncogenic potential in HCC. Some RARs showed the significant associations with the clinical features. Especially, the recurrent loss in 9p24.2-p21.1 and gain in 8q11.21-q24.3 are associated with the high tumor grade and MVI, respectively. Functional analysis showed that cytokine receptor binding and defense response to virus pathways are significantly enriched in high grade-related RARs. Taken together, our results and the strategy of analysis will help to elucidate pathogenesis of HCC and to develop biomarkers for predicting behaviors of HCC.

Implication of leucyl-tRNA synthetase 1 (LARS1) over-expression in growth and migration of lung cancer cells detected by siRNA targeted knock-down analysis

Molecular mechanism of lung carcinogenesis and its aggressive nature is still largely elusive. To uncover the biomarkers related with tumorigenesis and behavior of lung cancer, we screened novel differentially expressed genes (DEG) in A549 lung cancer cell line by comparison with CCD-25Lu, normal pulmonary epithelial cell line, using annealing control primer(ACP)-based GeneFishing system. Of the DEGs, over-expression of leucyl-tRNA synthetase 1 (LARS1) was prominent and this up-regulation was confirmed by immunoblotting and real-time quantitative RT-PCR analysis. In addition to A549 cell line, primary lung cancer tissues also expressed higher level of LARS1 mRNA than their normal counter tissues. To explore the oncogenic potential of LARS1 over-expression in lung cancer, we knocked-down LARS1 by treating siRNA and observed the tumor behavior. LARS1 knock-down cells showed reduced ability to migrate through transwell membrane and to form colonies in both soft agar and culture plate. Taken together, these findings suggest that LARS1 may play roles in migration and growth of lung cancer cells, which suggest its potential implication in lung tumorigenesis.

P-glycoprotein down-regulates expression of breast cancer resistance protein in a drug-free state

This study investigated whether P-glycoprotein (Pgp) and breast cancer resistance protein (BCRP) are linked in terms of expression. RT-PCR and Western blot analyses showed that the lung cancer cell line SK-MES-1/WT expressed BCRP. In a drug-free state, BCRP expression was significantly down-regulated in doxorubicin-resistant SK-MES-1/DX1000 cells overexpressing Pgp. Pharmacological inhibitors (PSC833 or verapamil) or siRNA for Pgp inhibited the down-regulation of BCRP, which was confirmed by confocal microscopy. PSC833 induced the phosphorylation of c-Jun NH2-terminal kinase (JNK) and c-Jun, while the JNK inhibitor SP600125 inhibited this effect. Dominant negative c-Jun decreased the expression of BCRP, but increased that of Pgp. These results indicate that Pgp down-regulates BCRP expression in a drug-free state in which JNK/c-Jun is involved.

Cerebral ventricle-brain ratio in monozygotic twins discordant and concordant for schizophrenia

1. Several studies on monozygotic twins discordant for schizophrenia showed that the cerebral ventricle-brain ratio (VBR) was larger in the twins with schizophrenia, as compared with the corresponding normal twins. 2. The results suggest that the difference of the VBR of the discordant twins was larger than that of the concordant twins of schizophrenia. 3. The authors studied the VBR in four monozygotic twin pairs discordant and four monozygotic twin pairs concordant for schizophrenia by computerized tomography. 4. In the discordant twins, all pairs showed that the VBR of the normal twins was smaller than that of the corresponding twins with schizophrenia. 5. The difference of the VBR of the discordant twins and that of the concordant twins of schizophrenia was not statistically different using Mann-Whitney U test. 6. The preliminary results suggest that the VBR enlargement in schizophrenia is not genetically controlled in monozygotic twins either discordant or concordant for schizophrenia. 7. In monozygotic concordant twins, the brain pathology may be heterogeneous.

Anticipation and imprinting in schizophrenia

Anticipation, i.e., a decrease in the age of onset and/or an increase in the severity of a disease in subsequent generations, and imprinting, i.e., different modes of parental transmission, have been suggested in trinucleotide repeat amplification diseases. The purpose of this study was to determine if anticipation and imprinting are associated with familial schizophrenia. Two generations of 49 schizophrenics from 24 families were studied. Ages of onset, numbers hospitalized, diagnostic subclasses of schizophrenia, amounts of antipsychotics, positive symptoms, negative symptoms, treatment resistance, and clinical course ratings, were compared between the two generations. The age of onset was significantly lower in the offspring generation, although there was no difference in the severity between the two generations. The negative symptom scores and clinical course scores in the offspring generation for paternal transmission were significantly higher than those for maternal transmission. Our results suggest the presence of imprinting and anticipation in schizophrenia.

Exclusion of five trinucleotide repeat (CAG and CCG) expansions in 17 families with schizophrenia

Trinucleotide repeat expansion diseases are characterized by anticipation. Several studies suggested the anticipation in schizophrenia. We studied five novel trinucleotide repeats identified by Li et al in a human brain cDNA library in 100 unrelated control subjects, and 57 subjects in 17 families with schizophrenia. The CTG-B43 and B45d, and CCG-A3 were not polymorphic in any unrelated control subjects or subjects with familial schizophrenia. The CTG-A4 had two alleles and the CTG-B1 three alleles. The two clones were not expanded in subjects with familial schizophrenia or unrelated healthy controls. There was no difference in allele frequency between unrelated control subjects and subjects in the families with schizophrenia. The allele frequencies in unaffected and affected subjects in the families with schizophrenia were not significantly different. There was no difference between the offspring and parental generations of affected subjects in the families with schizophrenia. The results suggest the exclusion of the five trinucleotide repeat expansions in the 17 families with schizophrenia.

Three CAG trinucleotide repeats on chromosome 6 (D6S1014, D6S1015, and D6S1058) are not expanded in 30 families with schizophrenia

Since 1991, more than five neuro-genetic disorders have been recognized to be caused by trinucleotide repeat expansions, and the list of such disease should grow. The diseases are characterized clinically by the phenomenon of anticipation, i.e., worsening of the disease phenotype in successive generations with increasing trinucleotide repeat expansion. The presence of anticipation in familial schizophrenia has been suggested. Several studies have provided supportive evidence that the suceptability locus for schizophrenia is on chromosome 6. Therefore, we analyzed three CAG trinucleotide repeat clones D6S1014, D6S1015, and D6S1058 on chromosome 6, which are polymolphic in 30 families with schizophrenia. No unusually, long alleles that would suggest abnormal expansion of more than 35 trinucleotide repeats were observed for these genes. Also, no statistically significant differences were found between the offspring and parental generations of affected subjects or between the affected and unaffected subjects in families with schizophrenia.

[Studies on electrophysiology of lysophosphatidylcholine and evaluation of its clinical significance]

The cellular electrophysiological effects of lysosphatidylcholine (LPC) were investigated by using patch-clamp whole cell recording and conventional microelectrode technique, LPC(10 microns) suppressed the sodium, background potassium and calcium current and the effect of LPC on activity of ionic channels was nonselective. Resting potential, action potential amplitude and maximal rate of rise of phase of action potential were decreased with LPC (50 microns) perfusing. The incidence of abnormal automaticity, early after depolarization (EAD) and delayed after depolarization (DAD) was higher. It is clearly shown that LPC accumulates at early time of myocardial ischemia and thus may induce ischemic arrhythmias.

[Role of the central alpha-receptors in the modulation of carotid sinus reflex of rats]

To investigate the effects of the central alpha-receptors on the carotid sinus reflex, phenoxybenzamine (PBZ, 2 micrograms/20 microliters) or yohimbine (Y, 2 micrograms/20 microliters) was injected into the lateral cerebral ventricle (LCV) and intracarotid sinus pressure (ISP)-mean arterial pressure (MAP) relationship curve was constructed and fitted by a Logistic function. The results were as follows: (1) After injection of PBZ into LCV, the ISP-MAP relationship curve shifted upward at a higher ISP level with decreased peak slope and MAP range while the ISP-slope curve shifted downward. (2) After injection of Y into LCV, the ISP-MAP relationship curve shifted upward at a higher ISP level with decreased peak slope and MAP range and increased threshold. The ISP-slope curve shifted downward significantly at 10.64, 15.96 kPa. The peak slope and MAP range of Y group decreased significantly as compared with that of the PBZ group. These results indicated that after blockage of central alpha-receptors the sensitivity of the sinus reflex decreased significantly, and the blockage action of alpha 2-receptor is greater than that of alpha 1-receptor.

[Effect of the central noradrenergic system on carotid sinus reflex in rats]

In order to study the effect of central noradrenergic system on the regulation of mean arterial pressure (MAP) by intracarotid sinus pressure (ISP), ISP-MAP relationship curves were constructed using isolated carotid sinus under the condition of injection of 6-OHDA (200 micrograms) into lateral ventricle or cauterization of locus coeruleus (LC) and compared with that obtained under the condition of control. All ISP-MAP curves can be fitted by a logistic functional plot whose characteristics can be defined by two parameters, i.e. coordinates of the inversion point of the slope of the curve and the MAP range related to the rate of change of slope factor with which carotid sinus pressure exerts its control. The results were as follows: After injection of 6-OHDA, the rate of change of the slope of the ISP-MAP curve is considerably slower than that of the normal control, thus showing a much compressed range of MAP by ISP, while the abscissa (i.e. position of ISP) of the slope inversion point of the curve shows practically no change. In comparison with the control, cauterization of LC causes a similar but less striking change of ISP-MAP curve than that of 6-OHDA injection experiment. All such differences were illustrated in Fig. 3. The above results indicated that the central noradrenergic system facilitates carotid sinus reflex and LC plays a dominant role.

Cadmium exposure and health effects among residents in an irrigation area with ore dressing wastewater

About 0.05 mg Cd l-1 was found in the irrigation water contaminated by the wastewater discharged from tungsten ore dressing plants, and about 1 mg Cd kg-1 was found in irrigated acid soils. The main sources of cadmium intake by residents of the polluted areas are agricultural products. The average intake of cadmium was 367-382 micrograms day-1, and for smokers 417 micrograms day-1. Among the residents who have been exposed to cadmium for more than 25 years, cadmium absorption (urinary cadmium greater than or equal to 10 micrograms g-1 creatine) was 60% and an early effect on the target organ (urinary cadmium greater than or equal to 15 micrograms g-1 creatinine and urinary beta 2-microglobulin greater than 500 micrograms g-1 creatinine) was detected in 17% of the sample of 433 persons. Levels of urinary cadmium and blood cadmium exceeded the critical value in the exposed group. The concentrations of urinary calcium, beta 2-microglobulin and N-acetyl-beta-D-glucosaminidase were significantly higher in residents of contaminated areas than in those of control areas. Case-control study of the residents shows that many have suffered from a nephropathy with tubulo-interstitial abnormalities. Owing to the combined cadmium effect, the cases with fractional beta 2-microglobulin excretion greater than 0.10 were 46% in the exposed population, and were much higher than that in the control group (20.3%).