Nonreciprocal P T-symmetric magnon laser in spinning cavity optomagnonics

We propose a scheme to achieve nonreciprocal parity-time (P T)-symmetric magnon laser in a P T-symmetric cavity optomagnonical system. The system consists of active and passive optical spinning resonators. We demonstrate that the Fizeau light-dragging effect induced by the spinning of a resonator results in significant variations in magnon gain and stimulated emitted magnon numbers for different driving directions. We find that utilizing the Fizeau light-dragging effect allows the system to operate at ultra-low thresholds even without reaching gain-loss balance. A one-way magnon laser can also be realized across a range of parameters. High tunability of the magnon laser is achieved by changing the spinning speed of the resonators and driving direction. Our work provides a new way to explore various nonreciprocal effects in non-Hermitian magnonic systems, which may be applied to manipulate photons and magnons in multi-body non-Hermitian coupled systems.

Hepatic vagotomy blunts liver regeneration after hepatectomy by downregulating the expression of interleukin-22

BACKGROUND

Rapid regeneration of the residual liver is one of the key determinants of successful partial hepatectomy (PHx). At present, there is a lack of recognized safe, effective, and stable drugs to promote liver regeneration. It has been reported that vagus nerve signaling is beneficial to liver regeneration, but the potential mechanism at play here is not fully understood.

AIM

To explore the effect and mechanism of hepatic vagus nerve in liver regeneration after PHx.

METHODS

A PHx plus hepatic vagotomy (Hv) mouse model was established. The effect of Hv on liver regeneration after PHx was determined by comparing the liver regeneration levels of the PHx-Hv group and the PHx-sham group mice. In order to further investigate the role of interleukin (IL)-22 in liver regeneration inhibition mediated by Hv, the levels of IL-22 in the PHx-Hv group and the PHx-sham group was measured. The degree of liver injury in the PHx-Hv group and the PHx-sham group mice was detected to determine the role of the hepatic vagus nerve in liver injury after PHx.

RESULTS

Compared to control-group mice, Hv mice showed severe liver injury and weakened liver regeneration after PHx. Further research found that Hv downregulates the production of IL-22 induced by PHx and blocks activation of the signal transducer and activator of transcription 3 (STAT3) pathway then reduces the expression of various mitogenic and anti-apoptotic proteins after PHx. Exogenous IL-22 reverses the inhibition of liver regeneration induced by Hv and alleviates liver injury, while treatment with IL-22 binding protein (an inhibitor of IL-22 signaling) reduce the concentration of IL-22 induced by PHx, inhibits the activation of the STAT3 signaling pathway in the liver after PHx, thereby hindering liver regeneration and aggravating liver injury in PHx-sham mice.

CONCLUSION

Hv attenuates liver regeneration after hepatectomy, and the mechanism may be related to the fact that Hv downregulates the production of IL-22, then blocks activation of the STAT3 pathway.

Parametrically amplified nonreciprocal magnon laser in a hybrid cavity optomagnonical system

We propose a scheme to achieve a tunable nonreciprocal magnon laser with parametric amplification in a hybrid cavity optomagnonical system, which consists a yttrium iron garnet (YIG) sphere and a spinning resonator. We demonstrate the control of magnon laser can be enhanced via parametric amplification, which make easier and more convenient to control the magnon laser. Moreover, we analyze and evaluate the effects of pump light input direction and amplification amplitude on the magnon gain and laser threshold power. The results indicate that we can obtian a higher magnon gain and a broader range of threshold power of the magnon laser. In our scheme both the nonreciprocity and magnon gain of the magnon laser can be increased significantly. Our proposal provides a way to obtain a novel nonreciprocal magnon laser and offers new possibilities for both nonreciprocal optics and spin-electronics applications.

[Effects of Notch-1/Twist-1 axis in the process of epithelial-mesenchymal transition of type II alveolar epithelial cell and its mechanism]

Objective: To study the role of Notch-1/Twist-1 axis in the process of epithelial-mesenchymal transition (EMT) of type II alveolar epithelial cells in pulmonary fibrosis (PF) and hope to provide a new theoretical basis for the pathogenesis of PF. Methods: Thirty rats were randomly divided into control group and bleomycin (BLM) group, 15 rats in each group. The PF rat model was induced by intratracheal injection of BLM (7 500 U/kg). Excised inferior lobe of left lung was fixed in 10% formalin for HE staining, Masson staining and transforming growth factor-beta 1 (TGF-β1) immunohistochemistry staining after BLM injection for 28 days. The cultured type II alveolar epithelial cells (RLE-6TN) were divided into 4 groups (Control group, transforming growth factor-beta 1 (TGF-β1) group, Notch-1 negative control siRNA (NC siRNA, 100 pmol/L) group and Notch-1 siRNA (100 pmol/L) group), each group was established nine holes. The cells were treated with TGF-β1 (5.0 ng/ml) for 24 h following NC siRNA or Notch-1 siRNA for 48 h. The mRNA and (or) proteins levels of TGF-β1, collagen I, collagen III, E-Cadherin, zonula occludens-1 (ZO-1), Vimentin, E-Cadherin, Notch-1, Notch-1 intracellular domain (NICD), Hes-1 and Twist-1 were detected in lung tissue and type II alveolar epithelial cells. Results: In vivo, compared with the control group, the alveolar atrophy, collapse and fusion occurred, alveolar septum widened significantly, and a large number of inflammatory cells infiltrated in the pulmonary interstitial of the rats in the BLM group. And compared with control group, BLM obviously increased collagen deposition and collagen I and collagen III expressions, while the expressions of ZO-1 and E-cadherin were decreased, and the expressions of Vimentin and N-cadherin were increased, and concomitantly with increasing Notch-1, NICD, Hes-1 and Twist-1 expression in lung tissues of rats (P＜0.01). In vitro, compared with control group, TGF-β1 treatment obviously induced collagen I, collagen III, Notch-1, NICD, Hes-1 and Twist-1 expressions, and the expressions of E-cadherin and ZO-1 were decreased and the expressions of Vimentin and N-cadherin were increased(P＜0.01). Compared with TGF-β1 group, Notch-1 siRNA treatment significantly inhibited the expressions of Notch-1, NICD, Hes-1 and Twist-1, and the expressions of E-cadherin and ZO-1 were increased and the expressions of Vimentin and N-cadherin were decreased, and also obviously reduced the expressions of collagen I and collagen III induced by TGF-β1 (P＜0.05 or P＜0.01). Conclusion: Notch-1/Twist-1 axis is involved in the EMT process of type II alveolar epithelial cells, suggesting that Notch-1/Twist-1 signaling may be involved in the development of pulmonary fibrosis.

Hb Hezhou [β64(E8)Gly→Ser; HBB: c.193G>A]: A Novel Variant on the β-Globin Gene

We report a novel mutation on the β-globin gene, Hb Hezhou [β64(E8)Gly→Ser; HBB: c.193G>A] that was detected in two unrelated Chinese individuals. Patient 1 also carried an α⁺-thalassemia (α⁺-thal) -α^4.2 (leftward) deletion, but hematological analyses showed no clinical consequences. Patient 2 was heterozygous for Hb Hezhou. Hemoglobin (Hb) analysis was performed using capillary electrophoresis (CE) and high performance liquid chromatography (HPLC). The Hb variant remained undetected using HPLC, while an additional peak was detected by CE. The finding of Hb Hezhou indicates that the possibilities of rare Hb variants should be alerted in the thalassemia screening program and precisely diagnosed depending on the Hb separation technique used.

[The expression and clinical significance of serum soluble programmed cell death ligand-1 in adult patients with community-acquired pneumonia]

To investigate the clinical significance of serum soluble programmed cell death ligand-1 (PD-L1) in adult patients with community-acquired pneumonia (CAP). A total of 44 CAP patients, 54 severe CAP patients and 30 healthy volunteers were recruited in this study. Serum soluble PD-L1 were detected. Univariate and multivariate regression analyses were used to assess the influence of multiple clinical variables on prognosis. Serum soluble PD-L1 level in severe CAP group was 98.20(57.94, 128.90) ng/L, which was significantly higher than that in the CAP group [59.32(33.55, 92.58) ng/L] and healthy controls [20.44(12.15, 36.20) ng/L] (all P<0.001). PD-L1 level was positively correlated with CRUB-65(r=0.481, P<0.001) and the pneumonia severity index (PSI) score (r=0.442, P<0.001). Univariate regression analysis showed that CURB-65 (HR=2.544, 95%CI 1.324-4.889, P=0.005), PSI score (HR=1.036, 95%CI 1.012-1.061, P=0.004), soluble PD-L1(HR=1.013, 95%CI 1.001-1.026, P=0.041) were risk factors of mortality during hospitalization. Multivariate regression analysis suggested that PSI score (HR=1.042, 95%CI 1.012-1.073, P=0.005), soluble PD-L1 (HR=1.011, 95%CI 1.002-1.071, P=0.020) were independent predictors for mortality risk in CAP patients. CAP patients with soluble PD-L1≥98.20 ng/L had a significantly lower survival rate than those with soluble PD-L1<98.20 ng/L (P=0.033). In conclusion, this study indicates that serum soluble PD-L1 level in CAP patients is correlated with the survival prognosis.

[Chrysin inhibited epithelial-mesenchymal transition of type Ⅱ alveolar epithelial cell by regulating NF-κB/Twist 1 signaling pathway]

This study aimed to assess whether chrysin(ChR) can inhibit epithelial-mesenchymal transition(EMT) of type Ⅱ alveolar epithelial cell and produce anti-pulmonary fibrosis effect by regulating the NF-κB/Twist 1 signaling pathway. Sixty rats were randomly divided into the control group, the bleomycin(BLC) group, BLC+ChR(50 mg·kg~(-1)) group and BLC+ChR(100 mg·kg~(-1)) group, with 15 rats in each group. The pulmonary fibrosis model was induced by intratracheal injection of BLC(7 500 U·kg~(-1)). Rats were orally administered with different doses of ChR after BLC injection for 28 days. The cells were divided into control group, TGF-β1 group(5 ng·mL~(-1)), and TGF-β1+ChR(1, 10, 100 μmol·L~(-1)) groups. The type Ⅱ alveolar epithelial cells were treated with TGF-β1 for 24 h, and then treated with TGF-β1 for 48 h in the presence or absence of different doses of ChR(1, 10 and 100 μmol·L~(-1)). The morphological changes and collagen deposition in lung tissues were analyzed by HE staining, Masson staining and immunohistochemistry. The mRNA and protein expression levels of collagen Ⅰ, E-cadherin, zonula occludens-1(ZO-1), vimentin, alpha smooth muscle actin(α-SMA), inhibitor of nuclear factor kappa B alpha(IκBα), nuclear factor-kappa B p65(NF-κB p65), phospho-NF-κB p65(p-p65) and Twist 1 in lung tissues and cells were detected by qPCR and Western blot, respectively. The animal experiment results showed that as compared with the BLC group, after administration of ChR for 28 days, bleomycin-induced pulmonary fibrosis in rats was significantly relieved, collagen Ⅰ expression in lung tissues was significantly reduced(P&lt;0.05 or P&lt;0.01), and EMT of alveolar epithelial cells was obviously inhibited [the expression levels of E-cadherin and ZO-1 were increased and the expression levels of vimentin and α-SMA were decreased(P&lt;0.05 or P&lt;0.01)], concomitantly with significantly reduced IκBα and p65 phosphorylation level in cytoplasm and decreased NF-κB p65 and Twist 1 expression in nucleus(P&lt;0.05 or P&lt;0.01). The cell experiment results showed that different doses of ChR(1, 10 and 100 μmol·L~(-1)) significantly reduced TGF-β1-induced collagen Ⅰ expression(P&lt;0.05 or P&lt;0.01), significantly inhibited EMT of type Ⅱ alveolar epithelial cells[the expression levels of E-cadherin and ZO-1 were increased and the expression levels of vimentin and α-SMA were decreased(P&lt;0.05 or P&lt;0.01)], and inhibited IκBα and p65 phosphorylation in cytoplasm and down-regulated NF-κB p65 and Twist 1 expression in nucleus induced by TGF-β1(P&lt;0.05 or P&lt;0.01). The results suggest that ChR can reverse EMT of type Ⅱ alveolar epithelial cell and alleviate pulmonary fibrosis in rats, and its mechanism may be associated with reducing IκBα phosphorylation and inhibiting NF-κB p65 phosphorylation and nuclear transfer, thus down-regulating Twist 1 expression.

[Impact of complicated myocardial injury on the clinical outcome of severe or critically ill COVID-19 patients]

Objective: To analyze the clinical characteristics of the severe or critically ill patients with novel coronavirus pneumonia (COVID-19), and evaluate the impact of complicated myocardial injury on the prognosis of these patients. Methods: A retrospective study was conducted in 54 patients who admitted to Tongji hospital from February 3, 2020 to February 24, 2020 and met the criteria of severe or critical conditions of COVID-19. The clinical characteristics and hospital mortality rate were analyzed and compared between the patients with or without myocardial injury, which was defined with 3 times higher serum cardiac troponin value. Results: The age of the 54 patients was 68.0(59.8, 74.3) years. Among all the patients, 24 (44.4%) patients were complicated with hypertension, 13 (24.1%) with diabetes, 8 (14.8%) with coronary heart disease, and 3 (5.6%) with previous cerebral infarction. During hospitalization, 24 (44.4%) of the patients were complicated with myocardial injury and 26 (48.1%) patients died in hospital. In-hospital mortality was significantly higher in patients with myocardial injury than in patients without myocardial injury (14 (60.9%) vs. 8 (25.8%), P=0.013). Moreover, the levels of C-reactive protein (153.6 (80.3, 240.7) ng/L vs. 49.8 (15.9, 101.9) ng/L) and N-terminal pro-B-type natriuretic peptide (852.0 (400.0, 2 315.3) ng/L vs. 197.0 (115.3, 631.0) ng/L) were significantly higher than patients without myocardial injury (all P<0.01). Conclusions: Prevalence of myocardial injury is high among severe or critically ill COVID-19 patients. Severe or critically ill COVID-19 patients with myocardial injury face a significantly higher risk of in-hospital mortality. The study suggests that it is important to monitor and manage the myocardial injury during hospitalization for severe or critically ill COVID-19 patients.

Altered resting-state functional connectivity between subregions in the thalamus and cortex in migraine without aura

BACKGROUND AND PURPOSE

Migraine is a complex and disabling neurological disorder, the exact neurological mechanisms of which remain unclear. The thalamus is considered to be the hub of the central processing and integration of nociceptive information, as well as the modulation of these processes.

METHODS

A total of 48 migraineurs without aura (MWoAs) during the interictal phase and 48 age- and sex-matched healthy controls underwent resting-state functional magnetic resonance imaging scans. We utilized masked independent component analysis and seed-based functional connectivity (FC) to investigate whether MWoAs exhibited abnormal FC between subregions in the thalamus and the cortex regions.

RESULTS

The MWoAs showed significantly weaker FC between the anterior dorsal thalamic nucleus and left precuneus. Additionally, MWoAs exhibited significantly reduced FC between the ventral posterior nucleus (VPN) and left precuneus, right inferior parietal lobule (R-IPL) and right middle frontal gyrus. Furthermore, the FC Z-scores between the VPN and R-IPL were negatively correlated with pain intensity in MWoAs. The disease duration of patients was negatively correlated with the FC Z-scores between the VPN and R-IPL.

CONCLUSION

These altered thalamocortical connectivity patterns may contribute to multisensory integration abnormalities, deficits in pain attention, cognitive evaluation and pain modulation. Pain sensitivity and disease duration are closely tied to abnormal FC between the VPN and R-IPL. Remarkably, recurrent headache attacks might contribute to this maladaptive functional plasticity closely related to pain intensity.

Machine learning for diagnosis of coronary artery disease in computed tomography angiography: A survey

Coronary artery disease (CAD) has become a major illness endangering human health. It mainly manifests as atherosclerotic plaques, especially vulnerable plaques without obvious symptoms in the early stage. Once a rupture occurs, it will lead to severe coronary stenosis, which in turn may trigger a major adverse cardiovascular event. Computed tomography angiography (CTA) has become a standard diagnostic tool for early screening of coronary plaque and stenosis due to its advantages in high resolution, noninvasiveness, and three-dimensional imaging. However, manual examination of CTA images by radiologists has been proven to be tedious and time-consuming, which might also lead to intra- and interobserver errors. Nowadays, many machine learning algorithms have enabled the (semi-)automatic diagnosis of CAD by extracting quantitative features from CTA images. This paper provides a survey of these machine learning algorithms for the diagnosis of CAD in CTA images, including coronary artery extraction, coronary plaque detection, vulnerable plaque identification, and coronary stenosis assessment. Most included articles were published within this decade and are found in the Web of Science. We wish to give readers a glimpse of the current status, challenges, and perspectives of these machine learning-based analysis methods for automatic CAD diagnosis.

[Expression and clinical significance of CCL18 in bronchoalveolar lavage fluid of connective tissue disease-associated interstitial lung disease]

Objective: To explore the expression and clinical significance of chemokine ligand 18 (CCL18) in Bronchoalveolar Lavage Fluid (BALF) of patients with connective tissue disease-associated interstitial lung disease (CTD-ILD). Methods: From January 2016 to June 2017, BALF of patients with rheumatoid arthritis-associated interstitial lung disease (RA-ILD group), patients with dermatomyositis-associated interstitial lung disease (DM-ILD group), and patients with primary Sjögren syndrome-associated interstitial lung disease (pSS-ILD group) of Peking University People's Hospital were collected. According to the prognosis of each group of patients during hospitalization, they were divided into the discharged and the died. Besides, 30 patients without ILD served as a control group. Levels of CCL18 in BALF of all patients were tested by enzyme linked immunosorbent assay (ELISA). Cells in BALF of RA-ILD group, DM-ILD group and pSS-ILD group were collected and analyzed by absolute different cell counts. Results of high-resolution CT (HRCT) of these three groups were scored. In addition, the area under the curve (AUC) of CCL18 in predicting mortality during hospitalization was calculated. Results: A total of 38 patients with RA-ILD, 54 patients with DM-ILD, and 35 patients with pSS-ILD were enrolled. Levels of CCL18 of those discharged patients of RA-ILD, DM-ILD, and pSS-ILD groups were 8.27(3.62, 14.36), 11.04 (5.86, 17.38), 5.25(2.68, 8.21) μg/L, respectively, which were all significantly higher than that of the control group [2.54(1.26, 3.66) μg/L, all P<0.05]. Furthermore, levels of CCL18 of those deceased patients of RA-ILD and DM-ILD groups were 18.28 (13.82, 22.39), 18.81 (16.29, 22.90) μg/L, which were significantly higher than that of the discharged patients of same group (all P<0.05). Levels of CCL18 were positively correlated with lymphocyte percentage in BALF of RA-ILD, DM-ILD and pSS-ILD groups (r=0.4356, 0.4029, 0.3939, respectively, all P<0.05). Besides, levels of CCL18 were significantly correlated with HRCT scores of RA-ILD and DM-ILD groups (r=0.4242, 0.3319, respectively, both P<0.05). Areas under the curve (AUCs) of CCL18 to predict mortality during hospitalization of RA-ILD and DM-ILD groups were 0.860, 0.851, respectively. Conclusions: Levels of CCL18 are elevated in BALF of CTD-ILD patients, and may be correlated with the severity and prognosis during hospitalization. CCL18 might be served as an indicator of the severity and prognosis of CTD-ILD.

[The effect of standardized lymphectomy and sampling of resected lymph nodes on TNM staging of resectable pancreatic head cancer]

Objective: To examine the effect of standardized lymphectomy and sampling of resected lymph nodes (LN) on TNM staging of resectable pancreatic head cancer. Methods: Consecutive patients with resectable pancreatic head cancer who received standard pancreatoduodenctomy at Department of General Surgery in Beijing Hospital from December 2017 to November 2018 were recruited as study group. After operation, the surgeon sampled lymph nodes from the fresh specimen following the Japanese Gastric Cancer Guidelines.Thirty-three cases were recruited in the study group and the mean age was (59.8±15.2) years.Pathologic reports from December 2015 to November 2016 were taken as control group, containing 29 cases with age of (57.0±13.0) years. Number of lymph nodes, standard-reaching ratio and positive nodes ratio were compared between two groups. According to the seventh edition and eighth edition of TNM staging, the changes of N staging and TNM staging were analysed. The quantitative data conforming to normal distribution were tested by independent sample t test, the quantitative data not conforming to normal distribution were tested by rank sum test, and the enumeration data were analysed by χ(2) test. Results: The basal data of the two groups were comparable (all P>0.05) . The number of lymph nodes sampled in the study group was 23.27±8.87, significantly more than in control group (12.86±5.90, t=0.653, P=0.000) .Ratio of cases with more than 15 nodes was 81.8% (27/33) in the study group and 34.5% (10/29) in the control group with statistical significance (χ(2)=14.373, P=0.000) . In the study group, the positive lymph node ratios of No. 17a+17b, 14a+14b, 8a+8p LN were 36.4% (12/33) , 30.3% (10/33) and 9.1% (3/33) respectively. The positive lymph node ratio in No.14a+14b LN was higher than in No.8 LN (χ(2)=4.694, P=0.030) . According to the change in N staging system in the AJCC eighth edition, 2 cases (6.1%, 2/33) changed from ⅠB to ⅡA, 7 cases (21.2%, 7/33) from ⅡA to ⅠB and 5 cases (15.2%, 5/33) changed from ⅡB to Ⅲ (25.0%, 5/20) . Conclusions: No.14 LN should be treated as the first station rather than second station because of the anatomic character and higher metastatic ratio. Standardised lymphectomy and sampling may increase the number of LN resected and improve the TNM staging of resectable pancreatic head cancer.

[Effects of EGCG on Proliferation, Cell Cycle and DAPK1 Gene Methylation of Acute Promyelocytic Leukemia NB4 Cell Line]

OBJECTIVE

To investigate the effects of epigallocatechin-3-gallate (EGCG) on proliferation and cell cycle of acute promyelocytic leukemia NB4 cell line and to clarify the molecular mechanism.

METHODS

NB4 cells were treated with 0,50,75,100 and 125µmol/L of EGCG for 24, 48, 72 and 96 h, respectively. The proliferation level of NB4 cells was measured by CCK-8 assay. The cell cycle progression of NB4 cells was assayed by flow cytometry. The mRNA expression levels of DNMT1, DNMT3a and DAPK1 were detected by RT-PCR. The methylation status of gene was tested by methylation specific PCR, and the expression level of DAPK1 protein was detected by Western blot.

RESULTS

The proliferation and cell cycle progression of NB4 cells treated with EGCG were inhibited and showed the characteristic of time-dependent and dose-dependent manner. The expression level of DAPK1 and DNMT3a decreased in NB4 cells treated with EGCG. The expression level of DAPK increased in NB4 cells treated with EGCG, while the methylation of DAPK1 gene decreased.

CONCLUSION

EGCG inhibits the proliferation and cell cycle progression of NB4 cells by inhibiting the expression of DNMT1 and DNMT3a and down-regulating the methylation status of DAPK1 gene.

The stability of Cu clusters and their adsorption for CH4 and CH3 by first principle calculations

Two-dimensional (2D) and three-dimensional (3D) Cu _n clusters (n indicates the atom number) and their adsorption behaviors for both methane (CH₄) and methyl (CH₃) are studied in this work using the density functional theory method, where n ranges from 6 to 20. In these small clusters, it is found that the CH₄ molecule is always adsorbed on the top site with the adsorption energy between -0.05 eV and -0.21 eV. Considering methane dehydrogenation, stronger adsorption for CH₄ is required, so 2D clusters with n = 7, 14, 15, and 16 and 3D clusters with n = 6, 10, 12, and 17 are found to have relatively stronger adsorption. However, for the adsorption of CH₃, there is an obvious even-odd oscillation change in the size of 3D clusters, while it is not clear in 2D clusters since one cannot find an even-odd change as n > 14. The weaker adsorption for CH₃ occurs on 3D clusters when n is even except 6 and also on 2D clusters when n = 6, 7, 10, and 12 with higher carbon poisoning resistance. Based on these calculated results, some Cu clusters which show good potential ability for methane dehydrogenation are provided, especially when n = 10 and 12 for 3D structures, and n = 7 for the 2D ones.

[Effects of Aquaculture on Ammonia-oxidizing Prokaryotes in Sediments of Eastern Lake Taihu]

The abundance and diversity of ammonia-oxidizing microorganisms in sediments of an aquacultural area of Eastern Lake Taihu were investigated. Real-time quantitative PCR was used to analyze the abundance of archaeal and bacterial amoA genes. Cloned libraries were constructed to investigate the structure and diversity of the microbial community. By comparing community characteristics of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in different zones, we found that:①Copy numbers of the bacterial amoA gene outnumbered those of archaeal amoA genes in the aquacultural zone; ②Diversity of AOA and AOB was higher in the aquaculture zone and control zone, respectively; ③ The dominant cluster of AOA and AOB in both sediments of aquiculture zone and control zone was Nitrosopumilus and Nitrosospira respectively. It was therefore the community structure of AOA (rather than AOB) in lake sediments that was affected by aquacultural activity.

Size-dependent Raman shift of semiconductor nanomaterials determined using bond number and strength

Significant variations in Raman shifts with decreasing material size, D, have been detected in Raman spectroscopy. In this study, we propose a simple and unified model to determine and explain the size-dependent Raman shift, ω(D), of low-dimensional semiconductor nanomaterials. ω(D) was found to be a function of bond number in a system, with an obvious decline in Raman shift observed when size dropped to the nanoscale. This arose from a decrease in coordination number, Z(D), and increase in single bond strength, ε(D). The predicted results show good agreement with experimental data for a series of semiconductor nanomaterials, showing that bond number can be used to calculate Raman shifts of nanomaterials. Moreover, this theoretical model was successfully applied to both single crystals and some binary semiconductor nanomaterials. Furthermore, bond number, which is directly related to the nanomaterial shape and size, becomes the only parameter required to determine ω(D) in this model, as both Z(D) and ε(D) can be determined from the bond number. This indicates that the established model has the potential to determine Raman shifts of nanomaterials with different shapes and sizes.

[Effects of Optimized Fish Farming on the Sediment Nutrients of Eastern Lake Taihu]

The farming of lake fisheries is an important part of the freshwater fishery industry in China. However, farming patterns of traditional fisheries maintain serious negative effects on the ecosystem of Eastern Lake Taihu. In recent years, the enclosure culture model of this lake has been optimized. In order to investigate the effects of aquaculture on the sediment properties, samples were collected from different areas of the lake (i.e. within the culture areas, outside the culture areas; from the crab-plant co-culture areas, mixed culture areas, ecological restoration areas, and control areas), in different months (January, March, April, August, and November), and at different depths (0-1 cm and 9-10 cm). The results of this sampling indicates that ① the concentrations of total nitrogen (TN) and total phosphorus (TP) in the sediments samples collected within the culture areas are slightly higher than samples collected outside the culture areas; ② compared to the crab-plant co-culture areas, lower concentrations of TN and TP are found in the samples collected from the mixed culture areas; ③ in the ecological restoration areas, aquatic plants exhibit certain positive effects with decreasing concentrations of TN and TP in the sediment. The lowest concentrations of TN and TP are detected in the sediment during the growing season of aquatic plants.

Identification of bioactives from Astragalus chinensis L.f. and their antioxidant, anti-inflammatory and anti-proliferative effects

This work was designed to obtain the valuable compounds with antioxidant, anti-proliferative and anti-inflammatory activities from Astragalus chinensis. Ethyl acetate fraction obtained from A. chinensis L.f. had significant antioxidant, anti-proliferative and anti-inflammatory activities. Subsequently, five single compounds were separated and purified, which were identified as formononetin (1), rhamnocitrin (2), calycosin (3), β-daucosterol (4), rhamnocitrin-3-O-β-d-glucoside (5). The results displayed that formononetin and rhamnocitrin exhibited significant cytotoxicity actions against tumor cell lines. Calycosin exerted the strongest anti-inflammatory effect of inhibition effects on NO production in macrophages.

[Terminal branches portal vein embolization for planed hepatectomy]

OBJECTIVE

To explore the application of the technique of terminal branches portal vein embolization(TBPVE)for planed hepatectomy.

METHODS

From February 2016 to June 2016, 4 patients with hepatocellular carcinoma underwent TBPVE and liver resection in Yuebei People's Hospital (n=3) and Jiangxi Ji'an Central People's Hospital (n=1). All of them were male and were 50, 64, 39 and 47 years old respectively. All the tumors located in the right lobe. All patients had the liver function of Child-Pugh A classification and liver cirrhosis level of G2S4. The standard liver volume (SLV) were 1 291, 1 109, 1 177 and 1 242 ml and estimated future liver remnant(FLR) were 315, 347, 306 and 323 ml respectively. The puncture site of TBPVE was determined by the three-dimensional reconstruction of portal vein. Three patients were punctured in the segment Ⅵ and the other one punctured in the segment Ⅲ. CT scan was repeated 2 weeks after TBPVE and FLR and FLR/SLV were calculated. All patients underwent right hepatectomy 2 weeks after TBPVE.

RESULTS

On the 14(th) day after TBPVE, the FLR of 4 patients were 529, 462, 469 and 498 ml which increased 67.9%, 33.1%, 53.3% and 54.2% compared with that before TBPVE, and FLR/SLV were 41.0%, 41.7%, 39.8% and 40.1% respectively. No severe complication occurred. Right hepatectomy were performed 2 weeks after TBPVE. No inflow blood control applied during the liver resection. The mean blood loss was 950 ml and the mean operating time was 3.3 hours (ranging from 3 to 4 hours). One patient had respiratory infection and two had slight jaundice and ascites for a short period. No other complication occurred.

CONCLUSION

The TBPVE could induce a rapid and large FLR volume that give chances to patients with small FLR to have liver resection for hepatocellular carcinoma.

[Pharmacokinetics and brain distribution of NMD/TMP-nanoparticles]

This study aims to prepare nimodipine/tetramethylpyrazine-loaded poly(D, L-lactide-co-glycolide) dual-drug nanoparticles (NMD/TMP-NPs) and investigate pharmacokinetics and brain distribution to evaluate the possibility of enhancing the drug effect of dual-drug nanoparticles. NMD/TMP-NPs were prepared via W/O/W emulsion solvent evaporation. Entrapment efficiency and drug loading of NMD/TMP-NPs were investigated by ultracentrifugation, and drug release behavior in vitro was studied by dialysis method. The pharmacokinetic and brain distribution were studied in SD mice administered intravenously with NMD/TMP-NPs in comparison with NMD-suspension, NMD/TMP-suspension and NMD-NPs, (NMD-NPs+TMP)-suspension. According to the results, the entrapment efficiency and drug loading of NMD were (79.71±0.73)%, (1.74±0.02)%, those of TMP were (40.26±1.51)% and (4.38±0.16)%. The nanoparticles showed the property of sustained release. On the basis of the major parameters for in vivo pharmacokinetic and brain distribution, t1/2β of NMD-suspension, NMD/TMP-suspension and NMD-NPs, (NMD-NPs+TMP)-suspension, NMD/TMP-NPs were (1.097±0.146), (1.055±0.06), (1.950±0.140), (1.860±0.096), (2.497±0.475） h, CL were (0.778±0.098), (1.133±0.111), (0.247±0.023), (0.497±0.040), (0.297±0.024) h•L-1, AUC0-t in rat plasma were (514.218±60.383), (352.916±33.691), (1 618.429±240.198), (804.110±75.804), (1 349.058±215.497) μg•h•L⁻¹, respectively, and AUC0-t in brain were 0.301 9, 0.624 8, 1.068 6, 1.313 0, 1.046 5 mg•h•L⁻¹, respectively. According to the in vivo study, the pharmacokinetic behavior of NMD were markedly prolonged by adding TMP or prepared dual-drug nanoparticles.

Effect of dobutamine on lung aquaporin 5 in endotoxine shock-induced acute lung injury rabbit

BACKGROUND

Dobutamine, a commonly used vasoactive drug, has been reported to reduce pulmonary edema and protect against acute lung injury (ALI) by up-regulating aquaporin 5 (AQP5) expressions. However, the underlying mechanism is still elusive.

METHODS

ALI was induced by intravenous injection of LPS. Seventy male New Zealand white rabbits were randomly divided into seven groups: sham group, ALI group, dobutamine low-dose group [group ALI + Dob (L)], dobutamine medium-dose group [group ALI + Dob (M)], dobutamine high-dose group [group ALI + Dob (H)], ALI + Dob (H) + ICI group and sham + ICI group. ICI 118,551, a potent and specific beta-2 antagonist, could block the effect of dobutamine. The animals were sacrificed at 3 h after endotoxic shock and lungs were removed. The arterial blood gas was analyzed. The lung wet to dry (W/D) ratio was determined. The level of cyclic AMP (cAMP) in lung tissue was assessed by ELISA. The expression of AQP5 protein was determined by western blotting and immunohistochemistry. The pathological alteration in lung tissue was evaluated by optical microscopy and electron microscope, and lung injury score was assessed.

RESULTS

Dobutamine increased AQP5 protein expression and cAMP level in a dose-dependent manner. Meanwhile, the degree of lung pathological and ultrastructural lesion was ameliorated and arterial blood gas was improved obviously. Additionally, W/D ratio and histological scores decreased significantly. However, the AQP5 protein expression and cAMP level were significantly decreased in group ALI + Dob (H) + ICI than that in group ALI + Dob (H), the degree of lung pathological and ultrastructural lesion was more serious in group ALI + Dob (H) + ICI than that in group ALI + Dob (H) and the arterial blood gas was not obviously improved.

CONCLUSIONS

These results suggested that protective effect of dobutamine against endotoxin shock-induced ALI may be due to its ability of up-regulating AQP5 protein expression via increasing intracellular cAMP concentration.

[Effect of As₂O₃on Hedgehog Pathway in Chronic Myeloid Leukemia Cells]

OBJECTIVE

To explore the effect of As₂O₃on Hedgehog pathway in chronic myeloid leukemia (CML) cells.

METHODS

The apoptosis of K562 cells was detected by MTT method and flow cytometry; the expressions of PTCH and SMO protein and mRNA in Hedgehog pathway were determined by Western blot and real-time PCR, respectively. Retults: The As₂O₃ could induce the apoptosis of K562 cells with optimal concentration 2 µmol/L and optimal time 24 hours. The expressions of PTCH and SMO protein and mRNA in Hedgehog pathway of K562 cells treated with As₂O₃at optimal concentration and optimal time were down-regulated.

CONCLUSION

The As₂O₃can down-regulate the expression of PTCH and SMO in Hedgehog pathway.

Functional analyses on antioxidant, anti-inflammatory, and antiproliferative effects of extracts and compounds from Ilex latifolia Thunb., a Chinese bitter tea

Ilex latifolia Thunb., widely distributed in China, has been used as a functional food and drunk for a long time. This study was aimed to identify the bioactive constituents with antioxidant, antitumor, and anti-inflammatory properties. I. latifolia was extracted with 95% ethanol and then partitioned into four fractions: petroleum ether fraction, ethyl acetate fraction, n-butanol fraction, and water fraction. Results showed that the ethyl acetate fraction was found to have significant ferric reducing antioxidant power activity, DPPH radical scavenging activity, and oxygen radical absorbance capacity, cytotoxicity against human cervix carcinoma HeLa cells, and inhibitory effect on NO production in macrophage RAW 264.7 cells. Five compounds were isolated from the ethyl acetate fraction, and they were identified as ethyl caffeate (1), ursolic acid (2), chlorogenic acid (3), 3,4-di-O-caffeoylquinic acid methyl ester (4), and 3,5-di-O-caffeoylquinic acid methyl ester (5), the last two of which were isolated for the first time from I. latifolia. Compounds 4 and 5 exhibited cytotoxicity actions against tumor cell line. Compound 3 showed the strongest anti-inflammatory activity of all the compounds. The results obtained in this work might contribute to the understanding of biological activities of I. latifolia and further investigation on its potential application values for food and drug.

Hydroxytyrosol and its potential therapeutic effects

As olive oil is the main source of calories in the Mediterranean diet, a large number of studies have been carried out to characterize its role in various diseases and exploitation for the prevention and treatment of hypertension, carcinogenesis, diabetes, atherosclerosis, and other diseases. As one of the major polyphenols present in virgin olive oil, hydroxytyrosol shows a variety of pharmacological activities such as antioxidant properties, anticancer, anti-inflammatory, and neuroprotective activities, and beneficial effects on the cardiovascular system, which show its potentiality for the development of dietary supplements. In the future, more attention should be paid to its action mechanism in vivo and synergistic effect. Further research will be performed to provide the theoretical basis for hydroxytyrosol and its derivatives use as health supplements.

Vimentin significantly promoted gallbladder carcinoma metastasis

BACKGROUND

The precise molecular mechanisms underlying the gallbladder carcinoma (GBC) metastasis has not been fully elucidated.

METHODS

In the present study, metastasis-associated proteins were identified by comparative proteomic analysis. The functional study of the candidate protein vimentin was further investigated. First, a pair of higher and lower metastatic sublines (termed GBC-SD/M3 and GBC-SD, respectively), originated from the same parental cell line, was screened by spontaneous tumorigenicity and metastasis in vivo in animal study and further characterized by metastatic phenotypes analysis in vitro. Subsequently, a proteomic approach comprised two-dimensional gel electrophoresis analysis and mass spectroscopy was used to identify and compare the protein expression patterns between higher metastatic GBC-SD/M3 and lower metastatic GBC-SD cell lines. Then twenty-six proteins were identified.

RESULTS

Among the 26 proteins identified, fourteen proteins were up-regulated and 12 proteins were down-regulated in GBC-SD/M3. Vimentin was identified and found to be overexpressed in GBC-SD/M3 as compared with GBC-SD. This result was further confirmed by quantitative PCR and Western blotting analysis. Furthermore, the cell migration and invasion potency of GBC-SD/M3 in vitro was remarkably suppressed after small interference RNA-mediated knockdown of vimentin. Moreover, immunoblot and immunohistochemical analysis on 12 human GBC specimens showed consistently increased vimentin expression in metastases compared with primary tumors.

CONCLUSION

Tumor vimentin level may reflect the pathological progression in some GBC and may be a useful marker for predicting tumor metastasis and a therapeutic target for the treatment of GBC patients with metastases.

Expression of the Arabidopsis thaliana histone gene AtHTA1 enhances rice transformation efficiency

We expressed the Arabidopsis thaliana histone AtHTA1 in rice under the control of the maize ubiquitin promoter. Transformation efficiencies of rice plants that constitutively expressed AtHTA1 were 28-44% higher than calli containing an empty vector control. Furthermore, co-infection of rice calli with a vector containing AtHTA1 and another vector with the target gene increased transformation by 27-50%. Thus, expression of AtHTA1 either transiently or in stably transformed cells improved rice transformation efficiency.

Anomalous photogalvanic effect of circularly polarized light incident on the two-dimensional electron gas in Al{x}Ga{1-x}N/GaN heterostructures at room temperature

Under normal incidence of circularly polarized light at room temperature, a charge current with swirly distribution has been observed in the two-dimensional electron gas in Al{0.25}Ga{0.75}N/GaN heterostructures. We believe that this anomalous charge current is produced by a radial spin current via the reciprocal spin Hall effect. It suggests a new way to research the reciprocal spin Hall effect and spin current on the macroscopic scale and at room temperature.

Comparison of four methods for the purification and refolding of human interleukin-2-mouse granulocyte/macrophage colony-stimulating factor fusion protein

The combination of IL-2 (interleukin-2) and GM-CSF (granulocyte/macrophage colony-stimulating factor) has been broadly studied in antitumour immune therapy, but its efficacy is uncertain. To better exert the activities of the two cytokines and study them in a mouse model, we have constructed a bifunctional protein, hIL-2-mGM-CSF (human IL-2-mouse GM-CSF), fused to a C-terminal tag of six histidine residues (His(6)). The fusion protein was expressed in Escherichia coli as IBs (inclusion bodies). After extracting and clarifying the IBs, four methods of protein purification and refolding were compared in order to optimize the preparation technique. Of these methods, the best result was obtained with a four-step process consisting of (1) purification with denaturing affinity chromatography, (2) followed by fully denaturing the protein with system conversion, (3) then refolding by isovolumetric ultrafiltration and (4) finally, purification by anion-exchange chromatography. The purity of the hIL-2-mGM-CSF was approx. 95%, yielding approx. 20 mg of protein/l of culture. The fusion protein retained the natural activities of IL-2 and GM-CSF, with specific activities of 8.7 x 10(6) and 1.1 x 10(7) i.u./mg respectively. Flow-cytometric analysis indicated that hIL-2-mGM-CSF could specifically bind to the corresponding receptor-positive cells. The present study provides important preliminary information for studying the antitumour activity of hIL-2-mGM-CSF in vivo, which will facilitate future clinical research into the use of hIL-2/hGM-CSF in immune therapy.

Quantification of Antibody (IgY) Titers in Hen Eggs Following Immunization and their Use in Detecting Cell Surface Molecules on Nitrocellulose Membranes

HLA-A*0201 alpha chain and beta2m were expressed from a prokaryotic system, and after refolding and purification, the alpha chain and beta2m were used to immunize eight laying hens. The titer of egg yolk antibody against alpha chain increased from 10(2) to 10(5.3) The titer of egg yolk antibody against beta2m increased from 10(1) to 10(4.7). The extent of titer increase is similar between the two antigens. An average of 135 mg purified polyclonal antibody (IgY) can be easily obtained from one egg yolk. The use of egg collection rather than serum collection is compatible with modern animal protection regulations. An average of 28 eggs were obtained from a laying hen every month, with a total amount of 3780 mg immunoglobulin extracted from one immunized hen every month, which would be equivalent to 630 mL of serum or 1260 mL of blood per month. Chickens are an optimal host for the production of polyclonal antibodies with high titer and high yield. Purified IgY was labeled with horseradish peroxidase and reacted with PBMC on nitrocellulose membranes indicating that the antibody can bind to the native conformation of class I HLA molecule on PBMC.

Analysis of the CDR3 length of TCR alphabeta T cells in the peripheral blood of patients with chronic hepatitis B

To clarify the characteristics of TCR alphabeta T cells in the peripheral blood of patients with chronic hepatitis B (CHB), we investigated the patterns of Complementarity Determining Region3 (CDR3) length distribution for all 24 TCR BV gene families and 32 TCR AV gene family in the peripheral blood lymphocytes of two patients with CHB and two healthy controls by immunoscope spectratyping technique. We found that the profiles of CDR3 length distribution for all TCR AV and TCR BV family showed Gaussian distribution (the polyclonal TCR alphabeta T cells) in healthy controls, however, the restricted usage of TCR BV and TCR AV family (the oligoclonal TCR alphabeta T cells) has been monitored in two CHB patients, furthermore, the oligoclonal TCR alphabeta T cells showed the different CDR3 sequences and length, it might be correlated to the different epitope of hepatitis B virus (HBV) or the different HLA type of the patients. Detailed analysis of the CDR3 length of TCR alphabeta T cells might be interesting to light on the further study of the individualized immunotherapy of CHB and the further research of the new T lymphocyte epitope vaccine of HBV.

Improved preparation of class I HLA tetramers and their use in detecting CMV-specific CTL

Different methods were used to prepare HLA tetramers and the yields of each method were compared. Our results indicate that preliminary refolding of the heavy chain (Hc) and light chain (beta 2m) yields more monomer than the typical conventional method with urea-solubilized Hc and beta 2m. We then used the corresponding tetramers to detect cytomegalovirus (CMV)-specific cytotoxic T lymphocytes (CTL). Increasing data suggest that the adoptive transfer of CMV-specific CTL constitutes an effective strategy against CMV infections. We designed a method that efficiently induces CMV-specific CTL to a higher frequency in vitro than is currently achieved. This method increased the percentage of CMV-specific CTL from below 1% to 20% of PBL, accounting for more than 40% of CD8+ T cells. Successful HLA tetramer preparation provides the basis for the subsequent detection of CMV-specific CTL in clinical applications.

Analysis of 10,000 ESTs from lymphocytes of the cynomolgus monkey to improve our understanding of its immune system

BACKGROUND

The cynomolgus monkey (Macaca fascicularis) is one of the most widely used surrogate animal models for an increasing number of human diseases and vaccines, especially immune-system-related ones. Towards a better understanding of the gene expression background upon its immunogenetics, we constructed a cDNA library from Epstein-Barr virus (EBV)-transformed B lymphocytes of a cynomolgus monkey and sequenced 10,000 randomly picked clones.

RESULTS

After processing, 8,312 high-quality expressed sequence tags (ESTs) were generated and assembled into 3,728 unigenes. Annotations of these uniquely expressed transcripts demonstrated that out of the 2,524 open reading frame (ORF) positive unigenes (mitochondrial and ribosomal sequences were not included), 98.8% shared significant similarities (E-value less than 1e-10) with the NCBI nucleotide (nt) database, while only 67.7% (E-value less than 1e-5) did so with the NCBI non-redundant protein (nr) database. Further analysis revealed that 90.0% of the unigenes that shared no similarities to the nr database could be assigned to human chromosomes, in which 75 did not match significantly to any cynomolgus monkey and human ESTs. The mapping regions to known human genes on the human genome were described in detail. The protein family and domain analysis revealed that the first, second and fourth of the most abundantly expressed protein families were all assigned to immunoglobulin and major histocompatibility complex (MHC)-related proteins. The expression profiles of these genes were compared with that of homologous genes in human blood, lymph nodes and a RAMOS cell line, which demonstrated expression changes after transformation with EBV. The degree of sequence similarity of the MHC class I and II genes to the human reference sequences was evaluated. The results indicated that class I molecules showed weak amino acid identities (<90%), while class II showed slightly higher ones.

CONCLUSION

These results indicated that the genes expressed in the cynomolgus monkey could be used to identify novel protein-coding genes and revise those incomplete or incorrect annotations in the human genome by comparative methods, since the old world monkeys and humans share high similarities at the molecular level, especially within coding regions. The identification of multiple genes involved in the immune response, their sequence variations to the human homologues, and their responses to EBV infection could provide useful information to improve our understanding of the cynomolgus monkey immune system.

Efficient production, purification, and application of egg yolk antibodies against human HLA-A*0201 heavy chain and light chain (beta2m)

The importance of eggs as a source of specific antibodies is well recognized. Egg yolk contains 8--20mg immunoglobulins (IgY) per milliliter. However, the major problem in separating IgY is to remove the high concentrations of lipids in egg yolk. We first used water dilution method to get the supernatant containing IgY, then purified the antibody by caprylic acid-ammonium sulfate method, and obtained specific antibody with satisfactory purity and activity. By comparison of these several methods, each has its advantages, one can be chosen to purify IgY according to practical need. The purified IgY produced by the immunized chickens can stain the human peripheral blood mononuclear cell effectively when labeled with fluorescent FITC.

Cyclodextrin derivative-coated quartz crystal microbalances for alcohol sensing and application as methanol sensors

Three novel cyclodextrin derivatives, mono(6-benzylimino-6-deoxy)-beta-cyclodextrin (2), mono-(6-cyclohexylamino-6-deoxy)-beta-cyclodextrin (3) and mono(6-benzylamino-6-deoxy)-beta-cyclodextrin (4), together with mono(6-phenylamino-6-deoxy)-beta-cyclodextrin (1), were synthesized and employed as sensing materials coated on quartz crystal microbalances (QCMs). Comparison of the responses to some alcohol and solvent vapours such as methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, acetone, chloroform and benzene indicated that these beta-cyclodextrin derivatives show considerable sensitivity and selectivity towards methanol. It shows a good linear relationship between the frequency shift and the methanol concentration in the range 3-160 mg L(-1) for 2-4 and 3-140 mg L(-1) for 1. The correlation coefficients are 0.9971, 0.9983, 0.9973 and 0.9977, respectively. The limit of detection (LOD) is 0.2 mg L(-1). When small amounts of other vapours co-exist, e.g., ethanol, propan-1-ol and acetone, the responses differ from that of pure methanol vapour, and a deduction method could eliminate this cross-sensitivity. The water cross-sensitivity was very low. These QCMs coated with cyclodextrin derivatives are employed as methanol sensors in the real atmosphere to detect on-line the concentration of methanol vapour.

Capillary Blood Flow Monitoring Using Laser Speckle Contrast Analysis (LASCA)

Coherent light scattered from an ensemble of moving scatterers produces a time-varying speckle pattern. The intensity fluctuations observed in a single speckle can be regarded either as a time-varying interference effect or as a Doppler beating effect. Techniques based on each of these approaches have been developed to analyze the fluctuations in an attempt to measure the velocities of the scatterers. Most of these methods measure the temporal statistics of the intensity fluctuations in a single speckle, i.e., at a single point. If a map of the velocity distribution is required, some form of scanning must be introduced. One way of avoiding the need to scan is to make use of the spatial statistics of time-integrated speckle. This is the basis of a technique, already described in the literature, called laser speckle contrast analysis (LASCA). In this article, we present a brief review of the theory linking the intensity fluctuations to the velocity and of the various techniques that have been proposed to measure them. We then describe the present configuration of our LASCA technique and describe some recent developments in our search for a real-time, noninvasive, full-field technique for visualizing capillary blood flow. © 1999 Society of Photo-Optical Instrumentation Engineers.

Studies of interaction between safranine T and double helix DNA by spectral methods

In this paper, the DNA affinity properties of Safranine T (ST), which features a phenazinyl group, were studied. The studies indicated that ST could intercalate into the stack base pairs of DNA. Intrinsic binding constants obtained by different spectral methods were consistent within experimental errors. They were of the order of 10(4) M-1 in DNA base pairs, and the binding site size was about 7 in DNA base pairs. Studies of fluorescence quenching by anionic quenchers and melting temperature of DNA all supported the intercalative binding of ST with DNA. The experiments also showed that electrostatic binding played an important role in the interaction of ST with DNA. This research offers a new intercalation functional group to DNA-targeted drug design.

[The effects of sex and age on DNA adduct formation in human lung tissue]

In order to evaluate the roles of sex and age in the formation of lung tissue DNA adducts, the levels of DNA adducts in human lung tissues from both patients with or without lung cancer were examined. The results showed there was a low correlation coefficient (r=0.11) between age and DNA adducts, but a significant difference in sex being observed. Smoking is a strong factor in the formation of DNA adducts. However, the role of endocrine can not be ruled out.

A competitive associative memory model and its dynamics

Conventional associative memory networks perform "noncompetitive recognition" or "competitive recognition in distance". In this paper a "competitive recognition" associative memory model is introduced which simulates the competitive persistence of biological species. Unlike most of the conventional networks, the proposed model takes only the prototype patterns as its equilibrium points, so that the spurious points are effectively excluded. Furthermore, it is shown that, as the competitive parameters vary, the network has a unique stable equilibrium point corresponding to the winner competitive parameter and, in this case, the unique stable equilibrium state can be recalled from any initial key.

Selective induction of rheumatoid factors by superantigens and human helper T cells

Production of autoantibodies specific for the Fc region of autologous IgG, called rheumatoid factors (RF), is a characteristic finding in patients with rheumatoid arthritis (RA). To study the requirements regulating the synthesis of these autoantibodies, we have cloned human helper T cells and co-cultured them with purified B cells. To mimic cognate T-B cell interaction, we have used bacterial superantigens that function by cross-linking HLA molecules on the B cell with selected T cell receptor (TCR) molecules expressing a particular polymorphism of the V beta gene segment. Data presented here demonstrate that the staphylococcal enterotoxin D (SE D), but not other bacterial superantigens, exhibits an ability to induce IgM, IgG, and especially RF production, in B cells from RA patients and normal individuals. Comparison with the polyclonal antibody production in B cell cultures driven by anti-CD3-stimulated T cell clones confirmed that SE D shifted the repertoire of secreted antibodies toward immunoglobulins with Fc binding specificity, suggesting that SE D preferentially stimulates RF+ B lymphocytes. B cells with the potential to secrete RF were highly frequent in RA patients, requiring as few as 150 peripheral B cells/culture to detect RF in the culture supernatants. SE D-induced RF synthesis was strictly dependent on the presence of selected CD4+T helper cells and required a direct membrane contact between B cells and T helper cells. Here, we propose a model that SE D selectively induces RF production depending on the availability of SE D responsive T cells in the TCR repertoire of the responder.

Effects of 1,3-dichloropropene on the kidney of Fisher 344 rats after pretreatment with diethyl maleate, buthionine sulfoximine, and aminooxyacetic acid

Acute nephrotoxicity of cis/trans-1,3-dichloropropene (DCP) was assessed in male Fisher 344 rats. Pretreatment of rats with corn oil, aminooxyacetic acid (AOA), buthionine sulfoximine (BSO), or diethyl maleate (DEM) was given intraperitoneally 1 h or 4 h prior to injection of DCP. Doses of DCP were 0, 25, 50, and 75 mg/kg intraperitoneally (4-5 animals per dose/pretreatment group). Urine was collected for 24 h. Excretion of creatinine, phosphorus, protein, N-acetylglucosaminidase (NAG), and the major metabolite of DCP, N-acetyl-S-(cis-3-chloroprop-2-enyl)-cysteine (3CNAC), was measured. Excretion of the metabolite, 3CNAC, increased in a dose-related manner from 0 to 50 mg/kg of DCP, but further increases were not seen at the 75 mg/kg dose. The pretreatments produced no alterations in the amounts of metabolite excreted when compared to corn oil controls. Zero-order metabolism or impaired metabolism is suggested to be occurring at high doses of DCP. The AOA pretreatment group showed no increase in the excretion of NAG, whereas other pretreatments (corn oil, BSO, DEM) showed elevations of NAG excretion at the highest DCP doses. AOA inhibits renal beta-lyase, an enzyme that mediates cleavage of mercapturic acid metabolites to toxic products. Since NAG excretion was not elevated in response to DCP with AOA pretreatment and was not raised by pretreatments that deplete glutathione, it is suggested that nephrotoxic effects of DCP may be mediated through the mercapturic acid metabolites on the kidney, rather than due to glutathione depletion per se.

Subacute cor pulmonale due to tumor embolization to the lungs

Six patients with subacute cor pulmonale due to tumor embolization to the lungs were reported from China. Five of the 6 patients suffered from progressive unrelenting dyspnea; 4 had completely normal cardiopulmonary findings on physical examination. Four of the 5 patients who had chest roentgenograms showed diffuse bilateral mottling of the lungs with no evidence of cardiomegaly. At autopsy right ventricular hypertrophy was present in all. The pathologic findings in the lungs consisted of multiple microscopic tumor emboli distributed diffusely in the pulmonary arterioles and/or perivascular lymphatics; the lumen of these vessels was obliterated with or without hyperplastic endarteritis. Although the outcome of this not uncommon clinicopathologic entity is generally fatal, early diagnosis followed by prompt effective therapy for the underlying primary neoplasm has been reported to prolong survival.