Escherichia coli-Induced cGLIS3-Mediated Stress Granules Activate the NF-κB Pathway to Promote Intrahepatic Cholangiocarcinoma Progression

Patients with concurrent intrahepatic cholangiocarcinoma (ICC) and hepatolithiasis generally have poor prognoses. Hepatolithiasis is once considered the primary cause of ICC, although recent insights indicate that bacteria in the occurrence of hepatolithiasis can promote the progression of ICC. By constructing in vitro and in vivo ICC models and patient-derived organoids (PDOs), it is shown that Escherichia coli induces the production of a novel RNA, circGLIS3 (cGLIS3), which promotes tumor growth. cGLIS3 binds to hnRNPA1 and G3BP1, resulting in the assembly of stress granules (SGs) and suppression of hnRNPA1 and G3BP1 ubiquitination. Consequently, the IKKα mRNA is blocked in SGs, decreasing the production of IKKα and activating the NF-κB pathway, which finally results in chemoresistance and produces metastatic phenotypes of ICC. This study shows that a combination of Icaritin (ICA) and gemcitabine plus cisplatin (GP) chemotherapy can be a promising treatment strategy for ICC.

[Association of sleep duration and physical exercise with dyslipidemia in older adults aged 80 years and over in China]

Objective: To explore the impact of sleep duration, physical exercise, and their interactions on the risk of dyslipidemia in older adults aged ≥80 (the oldest old) in China. Methods: The study subjects were the oldest old from four rounds of Healthy Aging and Biomarkers Cohort Study (2008-2009, 2011-2012, 2014 and 2017-2018). The information about their demographic characteristics, lifestyles, physical examination results and others were collected, and fasting venous blood samples were collected from them for blood lipid testing. Competing risk model was used to analyze the causal associations of sleep duration and physical exercise with the risk for dyslipidemia. Restricted cubic spline (RCS) function was used to explore the dose-response relationship between sleep duration and the risk for dyslipidemia. Additive and multiplicative interaction model were used to explore the interaction of sleep duration and physical exercise on the risk for dyslipidemia. Results: The average age of 1 809 subjects was (93.1±7.7) years, 65.1% of them were women. The average sleep duration of the subjects was (8.0±2.5) hours/day, 28.1% of them had sleep duration for less than 7 hours/day, and 27.2% had sleep for duration more than 9 hours/day at baseline survey. During the 9-year cumulative follow-up of 6 150.6 person years (follow-up of average 3.4 years for one person), there were 304 new cases of dyslipidemia, with an incidence density of 4 942.6/100 000 person years. The results of competitive risk model analysis showed that compared with those who slept for 7-9 hours/day, the risk for dyslipidemia in oldest old with sleep duration >9 hours/day increased by 22% (HR=1.22, 95%CI: 1.07-1.39). Compared with the oldest old having no physical exercise, the risk for dyslipidemia in the oldest old having physical exercise decreased by 33% (HR=0.67, 95%CI: 0.57-0.78). The RCS function showed a linear positive dose-response relationship between sleep duration and the risk for hyperlipidemia. The interaction analysis showed that physical exercise and sleep duration had an antagonistic effect on the risk for hyperlipidemia. Conclusion: Physical exercise could reduce the adverse effects of prolonged sleep on blood lipids in the oldest old.

[From treatment to whole course management: envisioning comprehensive management of Talaromycosis marneffei]

Talaromycosis marneffei has been increasing in recent years. Our understanding of this disease has gradually deepened through extensive basic and clinical research, but there are still many limitations. In this article, by incorporating the latest research advancements, we discuss important issues in managing Talaromycosis marneffei trends, aiming to guide effective prevention and control of the disease, improving public health, and reducing the healthcare burden.

[Clinical efficacy of the treatment of bilateral gluteal muscle contracture by inside-out iliotibial band release under arthroscopy in the supine position]

Objective: To investigate the clinical efficacy of bilateral gluteal muscle contracture treated with inside-out iliotibial band release under arthroscopy in the supine position. Methods: A prospective non-randomized controlled trial. Forty-six patients admitted to the Department of Sports Medicine, Senior Department of Orthopedics, the Fourth Medical Center of PLA General Hospital from April 2021 to August 2022 for bilateral gluteal muscle contracture and proposed surgical treatment were enrolled. The subjects were divided into two groups according to the preferred surgical protocols of the patients: the supine position group was treated with inside-out iliotibial band release under arthroscopy in the supine position, and the operation in lateral position group was carried out with outside-in iliotibial band release under arthroscopy in the lateral position. The total duration of non-surgical operations and the total duration of surgical operations were recorded for all patients. The gluteal muscle contracture disability scale within 3 days before surgery and at least 2 months after surgery were compared between the two groups, and the occurrence of complications between the two groups was compared too. Results: There were 26 cases in the supine position group, 11 males and 15 females with a mean age of (31.8±7.3) years; and there were 20 cases in the lateral position group, 7 males and 13 females with a mean age of (30.6±6.3) years. The differences in gender, age, body mass index (BMI) and postoperative follow-up time between the two groups were not statistically significant (all P>0.05). The total duration of non-surgical operations was shorter in the supine position group than in the lateral position group [(47.9±10.4) min vs (63.9±7.5) min, P<0.001]. There was no statistically significant difference in the total duration of surgical operations between the supine position group and the lateral position group [31.0(27.0, 43.5) min vs 33.0(24.8, 38.0) min, P>0.05]. The postoperative gluteal muscle contracture disability scales were significantly improved in both the supine position and lateral position groups when compared with those before the operation [93.0 (85.0, 98.0) vs 61.0 (50.5, 66.8), P<0.001 and 88.5±6.9 vs 63.6±9.6, P<0.001, respectively]. There was no statistically significant difference in the gluteal muscle contracture disability scale between the supine position and lateral position groups before and 2 months after surgery [59.3±11.9 vs 63.6±9.6 and 93.0 (85.0, 98.0) vs 89.5(84.0, 94.8), both P>0.05, respectively]. Two patients in each group developed subcutaneous hematoma after surgery, and all of them resolved within 2 weeks after surgery, the difference in complication incidence rate was not statistically significant (P>0.05). No postoperative complications such as fat liquefaction in the operated area, infection, decreased hip abductor muscle strength or nerve injury in the lower extremity were observed in both groups. Conclusion: The treatment of bilateral gluteal muscle contracture by inside-out iliotibial band release under arthroscopy in the supine position can effectively improve clinical efficiency, with definite efficacy, and it is an operative program worth promoting.

[Predictive value of ultrasound-guided anesthesia injection in arthroscopy for borderline developmental dysplasia of the hip]

Objective: To evaluate the value of ultrasound-guided intra-articular anesthetic injection in predicting postoperative outcomes for borderline developmental hip dysplasia (BDDH). Methods: A follow-up study. The clinical data of 37 BDDH patients who received ultrasound-guided intra-articular anesthetic injection and arthroscopic examination in the Department of Sports Medicine, Senior Department of Orthopedics, the Fourth Medical Center of PLA General Hospital from May 2018 to February 2021 were retrospectively analyzed. Among them, there were 17 males and 20 females with a mean age of (37.9±12.8) years. All patients underwent ultrasound-guided intra-articular anesthetic injection prior to arthroscopy, and were evaluated with hip physical examination before and after injection, as well as before and after arthroscopy, in order to obtain the visual analog score (VAS) of pain for seven assessments. The total VAS score was calculated based on these evaluations. Follow-up was conducted for at least 12 months. The effective rate of injection referred to the ratio of the improvement of VAS score after anesthetic injection to the total VAS score before injection. Pearson correlation analysis and Bland-Altman analysis were used to test the correlation between modified Harris hip score (mHHS) after ultrasound-guided intra-articular anesthetic injection and mHHS score after arthroscopic surgery. A binary logistic regression model was established to analyze the substantial clinical benefit (SCB) for patients. Following the logistic regression analysis, a receiver operating characteristic (ROC) curve was constructed to evaluate the predictive power of ultrasound-guided intra-articular anesthetic injection in achieving SCB in those patients. The optimal cut-off value for injection efficacy was determined based on the ROC curve when SCB was achieved. Results: The follow-up time for all patients was (26.3±7.6) months. After anesthetic injection for 20 minutes, the total VAS score of pain [M(Q₁,Q₃)] decreased from 13(8,23) points before injection to 1(0,4) points; and the mHHS score [M(Q₁,Q₃)] increased from 60(46,70) points before arthroscopy to 90(84,96) points after, with statistically significant differences before and after injection and before and after arthroscopy (both P<0.001). Pearson correlation analysis showed that the mHHS score after intra-articular anesthetic injection was positively correlated with the mHHS score after surgery (r=0.961, P<0.001). The area under the ROC curve for predicting SCB after arthroscopy with ultrasound-guided intra-articular anesthetic injection was 0.769 (95%CI: 0.561-0.976), the Youden index was 0.663, the cut-off value was 0.569 2, the sensitivity was 96.3%, and the specificity was 70.0%. Conclusions: The results of ultrasound-guided intra-articular anesthetic injection before arthroscopy can indicate the presence of intra-articular lesions, and the degree of pain relief after injection is proportional to the functional recovery after arthroscopy. Patients with intra-articular anesthetic injection efficacy>56.92% have better results in hip arthroscopy.

[Outcomes of fluoroscopy-free hip arthroscopy technique in the treatment of femoroacetabular impingement syndrome]

Objective: To evaluate the effect of fluoroscopy-free technique in the arthroscopic treatment of femoroacetabular impingement syndrome (FAIS). Methods: A retrospective cohort study. Clinical data of FAI patients treated with hip arthroscopy in the No.4 Medical Center, PLA General Hospital from October 2018 to December 2021 were retrospectively analyzed. The patients were divided into two groups according to the surgical procedure: the fluoroscopy group and the fluoroscopy-free group. The operation time and modified Harris hip score (mHHS), international hip outcome tool (iHOT12) and visual analogue scale (VAS) of hip joint pain before and after the operation were observed and compared between the two groups. And the incidence of surgical complications in the two groups were compared too. Results: A total of 460 patients (213 males and 247 females) [aged (32.6±8.3) years (15-67 years)] with valid follow-up were included in this study. There were 275 cases in the fluoroscopy-free group and 185 cases in the fluoroscopy group. The operation time was shorter in the fluoroscopy-free group when compared with that in the fluoroscopy group, and the difference was statistically significant [(93.36±12.54) min vs (115.62±6.03) min, P<0.001]. In both groups, the VAS scores decreased and the mHHS scores and iHOT12 scores improved significantly at the last follow-up when compared with those before the operation (all P<0.001); however, there was no significant difference in the scores between the two groups (all P>0.05). The complication rate in the fluoroscopy-free group was 10.18% (28/275), and it was 10.81%(20/185) in the fluoroscopy group (P=0.829). Conclusion: Fluoroscopy-free hip arthroscopy technique for FAI can avoid radiation and shorten the operation time, but it does not increase the incidence of complications with reliable clinical outcomes.

[Risk factors and chemoprophylaxis of ulcerative colitis-colorectal cancer]

Ulcerative colitis-colorectal cancer (UC-CRC) is one of the most serious complications in patients with ulcerative colitis (UC), with worse prognosis and higher mortality than sporadic colorectal cancer (CRC). Since most UC-CRC developed through the "inflammation-dysplasia-carcinoma" approach, early detection of dysplasia through identification of high-risk groups reasonable monitoring and active prevention are extremely important. However, there is no consensus on the risk factors of UC carcinogenesis and the drugs that can be used for chemoprevention currently. This article combined with relevant literature at home and abroad, reviewed the current risk factors and chemopreventive drugs for UC carcinogenesis, in order to provide reference for early prevention, early detection and early diagnosis of UC-CRC.

The study of multiple diagnosis models of human prostate cancer based on Taylor database by artificial neural networks

BACKGROUND

Prostate cancer (PCa) is the most common malignancy seen in men and the second leading cause of cancer-related death in males. The incidence and mortality associated with PCa has been rapidly increasing in China recently.

METHODS

Multiple diagnostic models of human PCa were developed based on Taylor database by combining the artificial neural networks (ANNs) to enhance the ability of PCa diagnosis. Genetic algorithm (GA) is used to select feature genes as numerical encoded parameters that reflect cancer, metastatic, or normal samples. Back propagation (BP) neural network and learning vector quantization (LVQ) neural network were used to build different Cancer/Normal, Primary/Metastatic, and Gleason Grade diagnostic models.

RESULTS

The performance of these modeling approaches was evaluated by predictive accuracy (ACC) and area under the receiver operating characteristic curve (AUC). By observing the statistically significant parameters of the three training sets, our Cancer/Normal, Primary/Metastatic, and Gleason Grade models' with ACC and AUC can be drawn (97.33%, 0.9832), (99.17%, 0.9952), and (90.48%, 0.8742), respectively.

CONCLUSION

These results indicated that our diagnostic models of human PCa based on Taylor database combining the feature gene expression profiling data and artificial intelligence algorithms might act as a powerful tool for diagnosing PCa. Gleason Grade diagnostic models were used as novel prognostic diagnosis models for biochemical recurrence-free survival and overall survival, which might be helpful in the prognostic diagnosis of PCa in patients.

Seed-borne endophytic Bacillus velezensis LHSB1 mediate the biocontrol of peanut stem rot caused by Sclerotium rolfsii

AIMS

This study aimed to obtain an antagonistic endophyte against Sclerotium rolfsii from peanut seeds, evaluate the biocontrol efficacy towards peanut stem rot and explore its antifungal mechanism against S. rolfsii.

METHODS AND RESULTS

Thirty-seven endophytic bacteria were isolated from peanut seeds, six of which exhibited stronger antagonistic activities against S. rolfsii (inhibition rate, IR of hyphae growth ≥70%). Strain LHSB1, the strongest antagonistic strain, was identified as Bacillus velezensis. LHSB1 showed 93·8% of radial growth inhibition of S. rolfsii hyphae and exhibited obvious antagonistic activity against another six pathogenic fungi of peanut. Pot experiments showed two different LHSB1 treatments both significantly reduced the disease incidence and severity of stem rot (P < 0·05) compared to the controls, and the biocontrol efficacy reached 62·6-70·8%, significantly higher than that of Carbendazim control (P < 0·05). Further analyses revealed LHSB1 culture filtrate significantly inhibited sclerotia formation and germination, caused the abnormalities and membrane integrity damage of S. rolfsii hyphae, which might be the possible mode of action of LHSB1 against S. rolfsii. Three antifungal lipopeptides bacillomycin A, surfactin A and fengycin A, were detected in LHSB1 culture extracts by UPLC-ESI-MS, which could be responsible for the biocontrol activity of LHSB1 against S. rolfsii.

CONCLUSION

Our results suggested that the seed-borne endophytic B. velezensis LHSB1 would be a tremendous potential agent for the biocontrol of peanut stem rot caused by S. rolfsii.

SIGNIFICANCE AND IMPACT OF THE STUDY

This comprehensive study provides a candidate endophytic biocontrol strain and reveals its antifungal mechanism against S. rolfsi. To the best of our knowledge, this is the first time that seed-borne endophytic B. velezensis was used as the biocontrol agent to control peanut stem rot.

Increasing of FKBP9 can predict poor prognosis in patients with prostate cancer

BACKGROUND

FK506 binding protein 9 (FKBP9) has been reported and identified for a long time, but its relationship with cancer is rarely studied. For example, the role of FK506 binding protein 9 in prostate cancer (PCa) is still unclear. Therefore, we decided to detect the expression level of FKBP9 in PCa and explore its clinical significance.

METHODS

The expression level of FKBP9 protein was detected by immunohistochemistry. In addition, it was demonstrated by high-throughput sequencing of mRNA levels in the TCGA (cancer genome atlas) dataset of 499 patients. Kaplan-meier analysis and Cox proportional hazard regression model were used to evaluate the relationship between FKBP9 expression and survival in prostate cancer patients.

RESULTS

The expression of FKBP9 was localized in the cytoplasm, which in normal prostate tissues was obviously lower than that in PCa tissues (P = 0.001). High expression of FKBP9 was related with lymph node metastasis (P = 0.022) and distant metastasis (P = 0.028). Kaplan-Meier survival analysis revealed that the BCR-free survival of PCa patients with high FKBP9 level was significantly shortened (P=0.041).

CONCLUSIONS

FKBP9 may be a cancer promoter that enhances PCa progression, and the level of FKBP9 may be used as an independent precursor of PCa patients.

[Clinical study of no necrotic cavity lavage after debridement and drainage in patients with infected pancreatic necrosis]

Objective: To observe the outcomes of no necrotic cavity lavage after debridement and drainage in patients with infected pancreatic necrosis(IPN). Methods: From February 2014 to August 2017, there were 89 patients who were diagnosed as IPN undergoing minimally invasive surgery with no necrotic cavity lavage and large caliber-wide channel drainage in Department of General Surgery, Xuanwu Hospital, Capital Medical University. There were 57 male and 32 female patients aging of (49.5±14.4)years (ranging from 23 to 84 years). The body mass index of 89 patients was (25.4±3.8)kg/m(2) (ranging from 17.6 to 36.7 kg/m(2)). Among the 89 patients, 37 cases(41.6%) of biliary pancreatitis, 10 cases (11.2%) of alcoholic pancreatitis, 16 cases(18.0%) of hyperlipidemic pancreatitis, and 26 cases(29.2%) of other reasons. Results: Of 89 patients, IPN in 6 patients(6.7%) resolved using only percutaneous catheter drainage; another 83 patients underwent laparoscopic debridement(n=3, 3.4%) or video-assisted debridement(n=80, 89.9%). No patient was conversed to laparotomy. The average operation frequency and surgery time was (2.3±1.7) times and (56.5±31.7) minutes.The median bleeding volume and total length of stay was 10(0-600) ml and 34(6-172) days separately. The complication rate(Clavien-Dindo grade≥Ⅲ) was 9.0%(8/89) which involved mainly abdominal hemorrhage (5/8) and digestive tract fistula formation (3/8). The overall mortality rate was 6.7%(6/89). Among them, 3 cases died of abdominal infection, bacteremia and multiple organ failure, 2 cases died of pulmonary infection and bacteremia and 1 case died of fungal infection. Conclusion: No necrotic cavity lavage after debridement and drainage operation is considered effective and safe for IPN patients.

[Dynamic investigation of nutritional risk in patients with malignant tumor during hospitalization]

Objective: To prospectively investigate the changes in nutritional status of patients with malignant tumors during hospitalization by using nutritional risk screening (NRS2002), and to analyze the correlation between the nutritional status and clinical outcomes . Methods: This was a prospective and parallel research done by multi-center collaboration from 34 hospitals in China from June to September 2014.Hospitalized patients with malignant tumors inthese departments (Department of Gastroenterology, respiratory medicine, oncology, general surgery, thoracic surgery and geriatrics)were investigated. Only the patients with age≥ 18 years and hospitalization time between 7-30 days were included. During hospitalization, the physical indexes of human bodywere measured, and the NRS 2002 scores, and monitored the nutritional support at the time points of admission and 24 hours before discharge were recorded.And whether there was a nutritional risk in hospitalized patients and its association with clinical outcomes were investigated. Results: A total of 2 402 patients with malignancies were enrolled in this study. Seventy fourpatients who did not complete NRS2002 were eliminated, and 2 328 patients were included. The number of the main diseases was the top five, including 587 cases of colorectal cancer, 567 cases of lung cancer, 564 cases of gastric cancer, 146 cases of esophageal cancer, and 119 cases of liver tumor. At the time of discharge, compared with admission, the BMI, body weight, grip and calf circumferences of patients with malignant tumor were significantly decreased (P<0.05). The total protein, albumin, prealbumin and hemoglobin were significantly lower than those at admission (P<0.05). In 2 328 patients who were completed nutritional risk screening, the rate of malnutrition at admission was 11.1% (BMI =18.5, 258/2 328) and the rate of malnutrition at discharge was 10.9% (BMI =18.5, 254/2 328), there were no significant differences (χ(2)=0.019 7, P=0.888). There were 1 204 patients with nutritional risk at admission (51.7%, NRS2002 score≥3)and 1 352 patients with nutritional risk at discharge (58.1%, NRS2002 score≥3), with significant differences (χ(2)=49.9, P<0.001). The incidence of nutritional risk in patients with colorectal, stomach, and lung tumors at discharge was significantly higher than that at admission (P<0.05). The infective complications and other complications of patients with nutritional risk were significantly greater than those without nutritional risk at admission and at discharge.ICU hospitalization stay of patients with nutritional risk was increased significantly than those without nutritional risk at admission(P=0.042). Hospitalization expenses of patients with nutritional risk was increased significantly than those of patients without nutritional risk at discharge(P<0.01). Conclusion: The patients with malignant tumor have a higher incidence rate of malnutrition at both admission and discharge and malnutritionhas correlation with adverse clinical outcomes.The aboveindicators did not improve significantly at discharge.Doctors should pay more attention to the nutritional status (screening and evaluation)of patients before discharge and use appropriate and adequate nutrition support in order to prevent the weight loss and improve the life quality of patients.

[Observation on intestinal viral shedding time of hand, foot and mouth disease induced by coxsackievirus A6]

Objective: To observe the intestinal viral shedding time in patients with hand, food and mouth disease (HFMD) induced by coxsackievirus A6 (CA6). Method: Throat swab specimens and stool specimens of HFMD children were collected from those admitted to Hangzhou Children's Hospital between May and October 2015, while fluorescence quantitative PCR was used to detect the viral load.Eeighteen cases of HFMD children were followed up, who were confirmed as CA6 infection via laboratory tests.Stool specimen was collected every 4-7 days, and fluorescence PCR was used for virus nucleic acid detection until the stool viral nucleic acids of infected children turned to be negative.The intestinal virus shedding time of CA6-infected HFMD was compared with the intestinal virus shedding time of 65 children with enterovirus 71 (EV71) infection and 44 children with coxsackievirus A16 (CA16) infection of the previous studies (from May to September 2012). Result: The median stool viral load was 25×10(5) copies/ml (55×10(4) copies/mL, 9×10(6) copies/ml) in CA6-infected children.The numbers of stool virus nucleic acid turning negative were 0 case, 4 cases, 9 cases, 3 cases and 2 cases in 18 children at 1st, 2nd, 3rd, 4th, 5th weeks. At 5th week, the stool virus nucleic acid of children in CA6 group all turned to be negative.The positive rates of stool virus nucleic acid in EV71 group and CA16 group at the 5th week, however, were 31% and 27% respectively.There were statistically significant differences in distribution of positive rate of stool virus nucleic acid between CA6 infected children with EV71 and CA16 infected children (χ(2)=13.894, 10.698, P<0.05). Conclusion: The longest intestinal virus shedding time for CA6-infected HFMD children was 5 weeks, which is obviously shorter than that of EV71- infected children and CA16-infected children.

Genomic innovations, transcriptional plasticity and gene loss underlying the evolution and divergence of two highly polyphagous and invasive Helicoverpa pest species

BACKGROUND

Helicoverpa armigera and Helicoverpa zea are major caterpillar pests of Old and New World agriculture, respectively. Both, particularly H. armigera, are extremely polyphagous, and H. armigera has developed resistance to many insecticides. Here we use comparative genomics, transcriptomics and resequencing to elucidate the genetic basis for their properties as pests.

RESULTS

We find that, prior to their divergence about 1.5 Mya, the H. armigera/H. zea lineage had accumulated up to more than 100 more members of specific detoxification and digestion gene families and more than 100 extra gustatory receptor genes, compared to other lepidopterans with narrower host ranges. The two genomes remain very similar in gene content and order, but H. armigera is more polymorphic overall, and H. zea has lost several detoxification genes, as well as about 50 gustatory receptor genes. It also lacks certain genes and alleles conferring insecticide resistance found in H. armigera. Non-synonymous sites in the expanded gene families above are rapidly diverging, both between paralogues and between orthologues in the two species. Whole genome transcriptomic analyses of H. armigera larvae show widely divergent responses to different host plants, including responses among many of the duplicated detoxification and digestion genes.

CONCLUSIONS

The extreme polyphagy of the two heliothines is associated with extensive amplification and neofunctionalisation of genes involved in host finding and use, coupled with versatile transcriptional responses on different hosts. H. armigera's invasion of the Americas in recent years means that hybridisation could generate populations that are both locally adapted and insecticide resistant.

[Research Progress of the Relationship between SUNDS and OSAHS]

Sudden unexplained nocturnal death syndrome （SUNDS） is always a difficulty in forensic medicine researches. Although the development of molecular genetics promotes the etiologic study of SUNDS, the pathogenesis of most such cases is still unclear. Sleep apnea syndrome （SAS） is one of the common forms of sleep disorders, and obstructive sleep apnea hypopnea syndrome （OSAHS） is the most common. In recent years, some domestic and international researches show that OSAHS is related to the development of cardiovascular disease, which may cause cardiac arrhythmia, even sudden death. This article reviews the relationship between SUNDS and OSAHS and aims to provide new ideas for the pathogenesis of SUNDS.

An evaluation study of research efficiency of the Guangzhou institute of respiratory diseases based on malmquist index

BACKGROUND

This study aimed to analyze the dynamic changes of the scientific research innovation efficiency of Guangzhou Institute of Respiratory Diseases (GIRD) during the year 2009-2013 to explore the reason for these changes and give some suggestions on how to improve the overall efficiency of the Institute.

METHODS

The panel data used in this study were taken from 19 research teams of GIRD during 2009 to 2013. Data envelopment analysis (DEA) based on Malmquist index (MI) was used to analyze the performance of each research team in terms of productivity changes over time. Data were analyzed using DEAP 2.1 software.

RESULTS

The annual average increase rate of total factor productivity (TFP), technological progress, technical efficiency, pure technical efficiency, and scale efficiency was 30.4%, 22.5%, 6.4%, 0.9%, and 5.4%, respectively from 2009 to 2013. The scientific research innovation efficiency of the GIRD was generally high and kept on growing. The increase of TFP was mainly caused by the progress of tech, the descending of TFP in some teams should be mainly attributable to the declining pure technical efficiency, and scale efficiency on the whole, maintaining a stable growth at a low speed.

CONCLUSIONS

To achieve higher scientific research innovation, GIRD not only needs to further improve the management level and introduce advanced management mode, but also needs to focus on optimization of resource allocation, as well as to strengthen the talent introduction, and continue to maintain the absorption of new technologies and innovation.

Overexpression of BUB1B contributes to progression of prostate cancer and predicts poor outcome in patients with prostate cancer

BUB1 mitotic checkpoint serine/threonine kinase B (BUB1B) is a member of the spindle assembly checkpoint protein family, which has been proven to be associated with many kinds of cancers. The aim of this study was to investigate whether BUB1B was correlated with progression and prognosis in patients with prostate cancer (PCa) and how BUB1B regulated the proliferation, migration, and invasion of PCa cell lines. Compared to benign prostate cells and tissues, both messenger RNA and protein expressions of BUB1B were statistically increased in PCa cell lines and tumor tissues. In vitro studies revealed that BUB1B overexpression enhanced the proliferation, migration, and invasion ability of PCa cell lines, whereas depletion of BUB1B did not affect the cell functions. Microarray analysis showed the positive staining of BUB1B was upregulated in the higher Gleason score group, which also correlated with advanced clinicopathological stage, higher serum prostate-specific antigen, metastasis, overall survival, and prostate-specific antigen failure. Furthermore, the survival analysis indicated that high expression of BUB1B was an independent predictor for shorter biochemical recurrence-free survival, which had no effect on overall survival. BUB1B plays an important role in tumor growth and progression, which can lead to its use as a potential biomarker for the diagnosis and prognosis of PCa.

miR-195 Inhibits Tumor Progression by Targeting RPS6KB1 in Human Prostate Cancer

PURPOSE

To investigate the involvement of hsa-miRNA-195-5p (miR-195) in progression and prognosis of human prostate cancer.

EXPERIMENTAL DESIGN

qRT-PCR was performed to detect miR-195 expression in both prostate cancer cell lines and clinical tissue samples. Its clinical significance was statistically analyzed. The roles of miR-195 and its candidate target gene, ribosomal protein S6 kinase, 70 kDa, polypeptide 1 (RPS6KB1) in prostate cancer progression were confirmed on the basis of both in vitro and in vivo systems.

RESULTS

miR-195 downregulation in prostate cancer tissues was significantly associated with high Gleason score (P = 0.001), positive metastasis failure (P < 0.001), and biochemical recurrence (BCR, P < 0.001). Survival analysis identified miR-195 as an independent prognostic factor for BCR-free survival of prostate cancer patients (P = 0.022). Then, we confirmed the tumor suppressive role of miR-195 through prostate cancer cell invasion, migration, and apoptosis assays in vitro, along with tumor xenograft growth, angiogenesis, and invasion in vivo according to both gain-of-function and loss-of-function experiments. In addition, RPS6KB1 was identified as a novel direct target of miR-195 through proteomic expression profiling combined with bioinformatic target prediction and luciferase reporter assay. Moreover, the reexpression and knockdown of RPS6KB1 could respectively rescue and imitate the effects induced by miR-195. Importantly, RPS6KB1 expression was closely correlated with aggressive progression and poor prognosis in prostate cancer patients as opposed to miR-195. Furthermore, we identified MMP-9, VEGF, BAD, and E-cadherin as the downstream effectors of miR-195-RPS6KB1 axis.

CONCLUSION

The newly identified miR-195-RPS6KB1 axis partially illustrates the molecular mechanism of prostate cancer progression and represents a novel potential therapeutic target for prostate cancer treatment.

Down-regulation of dual-specificity phosphatase 5 predicts poor prognosis of patients with prostate cancer

Dual-specificity phosphatase 5 (DUSP5), which specifically inactivates the extracellular signal-regulated kinase (ERK) 1/2 within the mitogen-activated protein kinase (MAPK) signaling, has recently been considered to be a tumor suppressor. However, its role in prostate cancer is still elusive. In this study, we performed immunohistochemistry analysis on human tissue microarray (TMA) to detect the DUSP5 protein expression pattern. The results indicated that DUSP5 was down-regulated in the human prostate cancer relative to the adjacent benign tissues (IRS: PCa = 4.29 ± 1.72 versus Benign = 4.89 ± 1.58, P = 0.04). In addition, when we linked the DUSP5 protein levels to the clinicopathological features of the patients, we found that the downregulation of DUSP5 was significantly associated with advanced pathological stage (P = 0.004) and high Gleason score (P = 0.009). Moreover, we attempted to validate these findings and investigate the prognostic value of DUSP5 in a publicly available microarray-based Taylor Dataset. Statistic analysis demonstrated that the downregulation of DUSP5 was closely correlated with high Gleason score (P = 0.011), positive metastasis (P < 0.001) and biochemical recurrence (BCR) (P = 0.016). More importantly, Kaplan-Meier analysis revealed that significant differences between patients with high and low DUSP5 expression level in regard to the BCR-free survival of overall (P = 0.009), non-metastatic (P = 0.006) and patients with Gleason score 7 (P = 0.044). Multivariate analysis by Cox regression indicated that DUSP5 could be an independent predictor for the risk of BCR (HR: 0.41, 95% CI: 0.2-0.82; P = 0.012). In summary, our findings disclose that DUSP5 may be an important tumor suppressor that inhibits the progression of PCa. The downregulation of DUSP5 may accurately predict poor prognosis in PCa patients.

Effects of fluoride and chloride on the growth of Chlorella pyrenoidosa

To compare the toxic action of fluoride (F(-)) and chloride (Cl(-)) on freshwater algae, effects of F(-) and Cl(-) on Chlorella pyrenoidosa growth were investigated by determination of the algal biomass and model analysis. Results showed that the exponential growth equation (D = D0 + ae(bT)) may be used to fit the relationship between cell density (D) of C. pyrenoidosa and exposure time (T), but F(-) and Cl(-) have significantly different effects on parameters a (initial quantity of algae at the exponential growth stage) and b (growth constant). In the range of experimental concentrations, F(-) inhibited C. pyrenoidosa growth, and percent inhibition increased with increasing exposure time and F(-) concentration. By contrast, Cl(-) either inhibited or enhanced C. pyrenoidosa growth depending on Cl(-) concentration and exposure time, and percent inhibition increased with increasing Cl(-) concentration but decreased with increasing exposure time. The dose-response equation: I = min + (max - min)/(1 + 10(lgEC50-lgC)) may be used to fit the relationship between percent inhibition (I) and F(-) or Cl(-) concentration (C); however, F(-) was distinct from Cl(-) in terms of effects on parameter 'min'. The EC50 values of F(-) and Cl(-) ranged from 118 to 170 mg/L and 19.73 to 36.33 g/L, respectively; the latter is much higher than the former. Thus F(-) has higher toxicity than Cl(-).

Assessing the susceptibility of cruciferous Lepidoptera to Cry1Ba2 and Cry1Ca4 for future transgenic cruciferous vegetables

Advances in transgenic plants expressing Bacillus thuringiensis (Bt) insecticidal gene(s) offer a promising alternative to traditional insecticides for control of lepidopteran pests on important cruciferous vegetable crops such as cabbage and cauliflower. A public-private partnership, the Collaboration on Insect Management for Brassicas in Asia and Africa (CIMBAA), was formed in 2005 with the goal of developing dual-gene Bt cauliflower and cabbage, initially for India, to replace the use of broad spectrum, traditional insecticides. As a first step in this effort, the major lepidopteran pests of cruciferous vegetable crops [Plutella xylostella (L.), Pieris rapae (L.), Pieris brassicae (L.), Crocidolomia binotalis (L.), Hellula undalis (F.), Diacrisia obliqua Walker, Spodoptera litura F., and Helicoverpa armigera (Hübner)] were collected over a large geographic area (India, Indonesia, Taiwan, China, Australia, and the United States) and tested against purified Cry1Ba2 and Cry1Ca4 toxins, the toxins proposed to be expressed in the CIMBAA plants. Our results demonstrate that Cry1Ba2 and Cry1Ca4 were effective against the primary target of the CIMBAA plants, P. xylostella, regardless of geographic location, and had LC50 values <1.3 ppm. Furthermore, one or both toxins were effective against the other major pest Lepidoptera, except for S. litura or H. armigera which were less susceptible. No cross-resistance has been found between Cry1Ba2 and Cry1Ca4, suggesting cry1Ba2+cry1Ca4 cauliflower and cabbage could be an effective and sustainable tool to control, P. xylostella, the key lepidopteran pest on cruciferous vegetable crops, as well as most other Lepidoptera. As the CIMBAA plants are being developed, further tests are needed to determine whether they will express these proteins at sufficient levels to control all the Lepidoptera. Sustainable use of the dual-gene plants also is discussed.

Effects of cyclooxygenase-2 non-selective and selective inhibitors on proliferation inhibition and apoptosis induction of esophageal squamous carcinoma cells

The objective of this study is to investigate the effects of aspirin and nimesulide on cell proliferation, apoptosis and its potential mechanisms in EC9706 and EC109 esophageal squamous carcinoma cells. EC9706 and EC109 cells were incubated with varying concentrations of aspirin and nimesulide, and the effects on cell proliferation and apoptosis were monitored by 3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyltetrazolium bromide and flow cytometry. Reverse transcription-polymerase chain reaction and Western blot assays were used to investigate expression of Bcl-2 and Bax. Prostaglandin E2 production was measured by enzyme linked immunosorbent assay. Pretreatment with aspirin and nimesulide inhibited EC9706 and EC109 cell growth in a time and dose-dependent manner, accompanied with a decrease of prostaglandin E2 production. In EC9706 cells, the mechanism of aspirin and nimesulide induced growth inhibition was a consequence of cell cycle arrest at the G(0)/G(1) check point. In EC109 cells, growth arrest was by induction of apoptosis, associated with downregulation of Bcl-2, but not Bax. In conclusion, aspirin and nimesulide could inhibit cell proliferation and induce apoptosis in esophageal squamous carcinoma cells. Cyclooxygenase-2 inhibitor may be a promising therapeutic agent for human esophageal squamous cell carcinoma.

CYP1A/regucalcin gene expression and edema formation in zebrafish embryos exposed to 2,3,7,8-Tetrachlorodibenzo-p-dioxin

In this study, zebrafish eggs were exposed to a relatively low concentration (50 pg/mL) of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) for 72 h and then transferred to vehicle/TCDD-free water for the remainder of the experiments. Mortality, heart rates, edema severity, CYP1A, and regucalcin gene expressions were investigated to study TCDD-induced toxicity in zebrafish during the early life stage. Results indicated that the 50 pg/mL TCDD caused severe and visible developmental toxicity. Further research of the long term and low concentration of TCDD exposure is required.

Development and Evaluation of an Air-Curtain Fume Cabinet with Considerations of its Aerodynamics

In order to avoid the inherent aerodynamic difficulties of the conventional fume hood, an innovative design--the 'air curtain-isolated fume hood' is developed. The new hood applies a specially designed air curtain (which is generated by a narrow planar jet and a suction slot flow at low velocities) across the sash plane. The hood constructed for the study is full size and transparent for flow visualization. The aerodynamic characteristics are diagnosed by using the laser-light-sheet-assisted smoke flow visualization method. Four characteristic air-curtain flow modes are identified in the domain of jet and suction velocities when the sash remains static. Some of these characteristic flow modes have much improved flow patterns when compared with those of the conventional fume hoods. From the viewpoint of the aerodynamics and mass transport, the results indicate that the air curtain properly setup across the sash opening allows almost no sensible exchange of momentum and mass between the flowfields of the cabinet and the outside environment. Two standard sulfur hexafluoride (SF6) tracer gas concentration measurement methods following the ANSI/ASHRAE 110-1995 standard and the prEN14175 protocol for static test are employed to examine the contaminant leakage levels. Results of the rigorous examinations of leakage show unusually satisfactory hood performance. The leakage of the tracer gas can approach almost null (<0.001 p.p.m.) if the jet and suction velocities are properly adjusted.

High IFN-alpha expression is associated with the induction of experimental autoimmune uveitis (EAU) in Fischer 344 rat

Th1-response plays a crucial role in determining pathogenesis of organ-specific autoimmune diseases. It is believed that both IL-12 and INF-alpha are initiators to regulate Th1-response. In our experimental autoimmune uveitis (EAU) model, both Lewis and Fischer 344 rats share the same MHC class II molecules, while Lewis rat is EAU susceptible and Fischer 344 rat is EAU resistant. However, under the same condition of immunization, if pertussis toxin (PTX) was injected intraperitoneally as an additional adjuvant, Fischer 344 rat can develop EAU. In this study we investigate which mechanisms are involved in the induction of EAU in CFA+R16+PTX-treated (CRP-treated) Fischer 344 rats. In vivo and in vitro data demonstrated that Th1-cytokine, IFN-gamma mRNA expression was significantly increased in disease target tissue-eyes and in draining lymph node cells of CRP-treated Fischer 344 rat. When IL-12 and IFN-alpha mRNA expression were compared in the experimental groups, only IFN-alpha mRNA expression was associated with EAU development. To distinguish the sources of IFN-alpha producing cells, it was observed that IFN-alpha expression was mainly produced by macrophages. It was further confirmed that normal macrophage from Fischer 344 rat was able to produce significant IFN-alpha in the presence of PTX. The data strongly suggested that IFN-alpha might be involved in initiating Th1-cell differentiation and in turn contribute to the induction of EAU. High IFN-alpha expression induced by PTX may represent a novel pathway to initiate Th1 response in Fischer 344 rat.

Synthesis and characterization of chiral N-O turns induced by alpha-aminoxy acids

Chiral alpha-aminoxy acids of various side chains were synthesized with high optical purity starting from chiral alpha-amino acids. The conformations of diamides 13a-e, 15, and 16 were probed by using NMR, FT-IR, and CD spectroscopic methods as well as X-ray crystallography. The right-handed turns with eight-membered-ring intramolecular hydrogen bonds between adjacent residues (called the N-O turns) were found to be preferred for D-aminoxy acid residues, and they were independent of the side chains. The rigid chiral N-O turns should have great potential in molecular design.

Aromatic dienophiles. 1. A theoretical study of an inverse-electron demand Diels-Alder reaction between 2-aminopyrrole and 1,3,5-triazine

This study is devoted to a detailed theoretical study of an inverse-electron demand Diels-Alder reaction (IDA) with 1,3,5-triazine as the diene and 2-aminopyrrole 1A(alpha) as the dienophile, which is a key step in a cascade reaction for the one-pot synthesis of purine analogues. Geometries were optimized with the B3LYP/6-31G* method and energies were evaluated with the MP2/6-311++G** method. This IDA reaction occurs through a stepwise mechanism, where the first step corresponds to the nucleophilic attack of 2-aminopyrrole to triazine to form a zwitterionic intermediate, which is in equilibrium with a neutral intermediate through a hydrogen transfer process, followed by a rate-determining ring-closure step. It is shown that the B3LYP method significantly overestimates the activation energy, whereas the MP2 method offers a reasonable activation barrier of 27.9 kcal/mol in the gas phase. The solvation effect has been studied by the PCM model. In DMSO, the calculated activation energy of the IDA reaction is decreased to 24.0 kcal/mol with a strong endothermicity of 17.4 kcal/mol due to the energy penalty of transforming two aromatic reactants into a nonaromatic IDA adduct. The possible stepwise [2+2] pathway is ruled out based on its higher activation and reaction energies than those of the [4+2] pathway. By comparing the IDA reactions of triazine to 2-aminopyrrole and pyrrole, we address two crucial roles of the alpha-amino substituent in lowering activation and reaction energies and controlling the reaction regiochemistry.

Induction of apoptosis by superoxide anion and the protective effects of selenium and Vitamin E

OBJECTIVE

The purpose of this study is to investigate the effect of superoxide anion on the apoptosis of cultured fibroblasts and the protective role of selenium and Vitamin E.

METHODS

Cultured fibroblasts (NIH3T3), with or without selenium or vitamin E in the medium, were treated by superoxide anion produced by xanthine/xanthine oxidase reaction system and changes in cell structure and DNA were observed microscopically and electrophoretically.

RESULTS

Apoptosis was observed when superoxide anion at a concentration of 5 nmol/L or 10 nmol/L had acted on the fibroblasts for 5-10 h. Selenium and Vitamin E in the medium inhibited the apoptosis significantly when their concentrations reached 1.15 mol/L and 2.3 mol/L respectively.

CONCLUSION

Selenium and vitamin E have protective effect against the apoptosis induced by superoxide anion. The effect of selenium is more remarkable than that of vitamin E.

Reactions of tetrakis(dimethylamide)-titanium, -zirconium and -hafnium with silanes: synthesis of unusual amide hydride complexes and mechanistic studies of titanium-silicon-nitride (Ti-Si-N) formation

M(NMe(2))(4) (M = Ti, Zr, Hf) were found to react with H(2)SiR'Ph (R' = H, Me, Ph) to yield H(2), aminosilanes, and black solids. Unusual amide hydride complexes [(Me(2)N)(3)M(mu-H)(mu-NMe(2))(2)](2)M (M = Zr, 1; Hf, 2) were observed to be intermediates and characterized by single-crystal X-ray diffraction. [(Me(2)N)(3)M(mu-D)(mu-NMe(2))(2)](2)M (1-d(2), 2-d(2)) were prepared through reactions of M(NMe(2))(4) with D(2)SiPh(2). Reactions of (Me(2)N)(3)ZrSi(SiMe(3))(3) (5) with H(2)SiR'Ph were found to give aminosilanes and (Me(2)N)(2)Zr(H)Si(SiMe(3))(3) (6). These reactions are reversible through unusual equilibria such as (Me(2)N)(3)ZrSi(SiMe(3))(3) (5) + H(2)SiPh(2) right arrow over left arrow (Me(2)N)(2)Zr(H)Si(SiMe(3))(3) (6) + HSi(NMe(2))Ph(2). The deuteride ligand in (Me(2)N)(2)Zr(D)Si(SiMe(3))(3) (6-d(1)) undergoes H-D exchange with H(2)SiR'Ph (R' = Me, H) to give 6 and HDSiR'Ph. The reaction of Ti(NMe(2))(4) with SiH(4) in chemical vapor deposition at 450 degrees C yielded thin Ti-Si-N ternary films containing TiN and Si(3)N(4). Ti(NMe(2))(4) reacts with SiH(4) at 23 degrees C to give H(2), HSi(NMe(2))(3), and a black solid. HNMe(2) was not detected in this reaction. The reaction mixture, upon heating, gave TiN and Si(3)N(4) powders. Analyses and reactivities of the black solid revealed that it contained -H and unreacted -NMe(2) ligands but no silicon-containing ligand. Ab initio quantum chemical calculations of the reactions of Ti(NR(2))(4) (R = Me, H) with SiH(4) indicated that the formation of aminosilanes and HTi(NR(2))(3) was favored. These calculations also showed that HTi(NH(2))(3) (3b) reacted with SiH(4) or H(3)Si-NH(2) in the following step to give H(2)Ti(NH(2))(2) (4b) and aminosilanes. The results in the current studies indicated that the role of SiH(4) in its reaction with Ti(NMe(2))(4) was mainly to remove amide ligands as HSi(NMe(2))(3). The removal of amide ligands is incomplete, and the reaction thus yielded "=Ti(H)(NMe(2))" as the black solid. Subsequent heating of the black solid and HSi(NMe(2))(3) may then yield TiN and Si(3)N(4), respectively, as the Ti-Si-N materials.

[Role of hydrogen peroxide in promoting proliferation and transformation of rat liver oval cell line WB-F344]

OBJECTIVE

To study the role of hydrogen peroxide (H2O2) in promoting proliferation and transformation of rat liver oval cell line WB-F344.

METHODS

Culturing WB-F344 cells were stimulated directly by H2O2. The effect of H2O2 in promoting proliferation of WB cells was investigated by using MTT colorimetric analysis and 3H-TdR incorporation liquid scintillation counter. The normal WB cells and the WB cells initiated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) were both promoted by stimulating continuously with H2O2 of low concentration (800 nmol/L). The transformation effect was tested by morphologic observation, karyotype analysis, and anchorage-independent growth assay.

RESULTS

Proliferation of WB cells was induced obviously by H2O2 of low concentration for only one time. The normal WB cells and the WB cells initiated with MNNG were transformed by action with H2O2 of low concentration continuously for 28 days and typical morphologic characters of transformed cells were observed. In karyotype analysis the cells chromosome number changed and the frequency of structure aberration raised dramatically. Otherwise the transformed cells could form clone on self-solid culture medium.

CONCLUSIONS

The biological effects of H2O2 were related to the low dose concentration in promoting proliferation and transformation of liver oval cells indicating its important role in hepatocarcinogenesis. Therefore antioxidants should be able to provide a new clue in prevention and cure of hepatoma.

Roles of IL-4 and other factors in the trichosanthin-induced ovalbumin-specific IgE response

AIM

To study the mechanism of trichosanthin (TCS)-induced ovalbumin (OVA)-specific immunoglobulin E (IgE) response in vivo.

METHODS

To determine whether interleukin-4 (IL-4) was involved in TCS-induced IgE production, TCS and OVA co-immunized mice were treated with anti-IL-4 monoclonal antibodies (mAb) and OVA-specific serum IgE production was measured by enzyme-linked immunosorbent assay (ELISA). To distinguish whether recombinant IL-4 (rIL-4) was sufficient to support OVA-specific IgE response, OVA alone immunized mice were treated with rIL-4 and OVA-induced IgE production were examined by ELISA in the serum. To determine whether additional factors were involved in TCS-induced IgE response, th e kinetic expression of CD40 ligand (CD40L), tumor necrosis factor-alpha (TNF-alpha), and interleukin-13 (IL-13) were measured by semi-quantitative RT-PCR in draining mesenteric lymph node (MLN) from TCS-immunized mice.

RESULTS

TCS-induced OVA-specific IgE production was suppressed by anti-IL-4 antibody, whereas IL-4 alone could not induce OVA-specific IgE production. CD40L, TNF-alpha, and IL-13 all expressed high levels in MLN after both primary and secondary immune responses. Among them CD40L had the similar transient expression peak to that of IL-4.

CONCLUSION

IL-4 was indispensable for TCS-induced OVA-specific IgE production, and the other three factors examined may also be involved in, but CD40L may play a more important role.

Theoretical studies on alkyne addition to molybdenum alkylidenes: the preference of alpha- and beta-additions

The addition of alkynes HC=CR to Mo(NH)(CH(2))(OR')(2) (R = H, Me, Ph; R' = CH(3), CF(3)) has been studied with both ab initio molecular orbital and density functional calculations. Geometry optimizations were carried out with the HF/3-21G, HF/HW3, and B3LYP/HW3 methods. The transition structures for these addition reactions are in distorted trigonal bipyramidal geometries, similar to those of alkene additions. The calculated activation enthalpy for HC=CH addition to Mo(NH)(CH(2))(OR')(2) is about 10.3 kcal/mol for R' = CH(3) and about 2.3 kcal/mol for R' = CF(3), indicating a significant preference for acetylene addition to Mo(NH)(CH(2))(OCF(3))(2) over Mo(NH)(CH(2))(OCH(3))(2). These barriers are higher than those of the corresponding ethylene addition by about 2-4 kcal/mol, even though the reaction of acetylene is much more exothermic. The alpha-addition of HC=CR (R = Me, Ph) is found to be considerably more favorable than the beta-addition to Mo(NH)(CH(2))(OR')(2). Interestingly, the alpha-addition has a lower activation energy, while the beta-addition has a higher activation energy, compared to that of the parent acetylene addition. Thus, alpha-addition is intrinsically favored over beta-addition by over 4 kcal/mol. This preference is reduced by solvent effect. All these can be explained by a destabilizing interaction between the nonreacting pi-orbital of alkyne and one of the lone pairs on the imido nitrogen. The steric effect of the bulky ligands in the real catalysts is also investigated qualitatively by the PM3 method. These studies give results in good accord with the experimentally observed regioselectivity.

A theoretical study on the mechanism and diastereoselectivity of the Kulinkovich hydroxycyclopropanation reaction

A detailed mechanism for the Kulinkovich hydroxycyclopropanation reaction has been explored with density functional theory calculations on the reactions between R(1)COOMe and Ti(OMe)(2)(CH(2)CHR(2)) (R(1) and R(2) are hydrogen and alkyl groups). Addition of ester to titanacyclopropane is found to be fast, exothermic, and irreversible. It has a preference for the alpha-addition manifold over the beta-addition manifold in which its cycloinsertion transition states suffer from the steric repulsion between the R(2) and ester. The following intramolecular methoxy migration step is also exothermic with reasonable activation energy. The cyclopropane-forming step is the rate-determining step, which affords the experimentally observed cis-R(1)/R(2) diastereoselectivity in the alpha-addition manifold by generating cis-R(1)/R(2) 1,2-disubstituted cyclopropanol when R(1) is primary alkyl groups. On the contrary, the unfavored beta-addition manifold offers the diastereoselectivity contradicting the experimental observations. The effects of R(1) and R(2) on the regio- and stereoselectivity are also discussed.

A theoretical study on the origin of cooperativity in the formation of 3(10)- and alpha-helices

By using a simple repeating unit method, we have conducted a theoretical study which delineates the preferences for beta-strand, 2(7)-ribbon, 3(10)-helix, and alpha-helix formation for a series of polyglycine models up to 14 amino acid residues (Ac-(Gly)(n), n = 0, 1, 2,., 14). Interactions among residues, which result in cooperativity, are clearly indicated by variations in calculated energies of the residues. Whereas no cooperativity is found in the formation of beta-strands and 2(7)-ribbons, there is a significant cooperativity in the formation of 3(10)- and alpha-helices, especially for the latter. In the case of alpha-helices, the 14th residue is more stable than the 3rd by about 3 kcal/mol. A good correlation between calculated residue energy and residue dipole moment was uncovered, indicating the importance of long-range electrostatic interactions to the cooperativity. The results of our calculations are compared with those of the AMBER and PM3 methods, and indicate that both methods, AMBER and PM3, need further development in the cooperative view of electrostatic interactions. The result should be of importance in providing insight into protein folding and formation of helical structures in a variety of polymeric compounds. This also suggests a strategy for the development of more consistent molecular mechanics force fields.

Conformational Features and Anion-Binding Properties of Calix[4]pyrrole: A Theoretical Study

The conformational preference of calix[4]pyrrole and its fluoride and chloride anion-binding properties have been investigated by density functional theory calculations. Geometries were optimized by the BLYP/3-21G and BLYP/6-31G methods, and energies were evaluated with the BLYP/6-31+G method. To model the effect of medium, the SCIPCM solvent model was also employed. Four typical conformations of the parent substituent-free calix[4]pyrrole were studied. Both in the gas phase and in CH(2)Cl(2) solution, the stability sequence is predicted to be 1,3-alternate > partial cone > 1,2-alternate > cone. The cone conformation is predicted to be about 16.0 and 11.4 kcal/mol less stable in the gas phase and CH(2)Cl(2) solution, respectively. This is mainly due to electrostatic repulsions arising from the all-syn pyrrole/pyrrole/pyrrole/pyrrole arrangement present in this conformer. The existence of possible 1:1 and 1:2 anion-binding modes were explored in the case of fluoride anion, and the factors favoring the 1:1 binding mode are discussed. The calculated binding energy for fluoride anion is about 15 kcal/mol larger than that for chloride anion. The calculated binding energy for chloride anion agrees with the experimental value very well. The presence of meso-alkyl substituents destabilizes the cone conformer with respect to the 1,3-alternate conformer and, therefore, reduces the anion-binding affinity by 3-4 kcal/mol. The strength of N-H- - -anion hydrogen bonds in the various structures subject to study were estimated on the basis of the calculated anion-binding energies and the predicted structural deformation energies of substituent-free calix[4]pyrrole.

Effects of glutamine on tumor growth and apoptosis of hepatoma cells

AIM

To explore the effects of glutamine on growth and apoptosis of hepatoma cells.

METHODS

Mice inoculated with hepatoma cell (H22) suspension subcutaneously at right axilla were orally administered with glutamine (GLN) solution. Human hepatoma cell culture (SMMC-7721) was treated with different concentrations of GLN solution. The content of malondialdehyde (MDA) and nitric oxide (NO) was detected in mice plasma and cell culture, and that of glutathione (GSH) was decected in cells. The inoculated tumor's growth in the mice and hepatoma cells' proliferation and apoptosis were observed.

RESULTS

When mice were administered orally with GLN solution (300 mg/kg), the growth of inoculated hepatoma was suppressed in the mice. When different concentrations of GLN solution were added in human hepatoma cell culture, the hepatoma cells' proliferation was inhibited and cells were induced to apoptosis, which was dependent on GLN concentration; meanwhile the contents of NO rose both in mice plasma and in cell culture, however MDA contents were slightly lowered in both, and the activity of GSH increased in the cells which had been ultrasonically shattered.

CONCLUSION

Hepatoma cell apoptosis and tumor growth inhibition by GLN may be associated with its antioxidative activity and its intervention in hepatoma cell proliferation, and simultaneous release of NO.

The expression of glucose regulated protein-94 in colorectal carcinoma cells treated by sodium butyrate

The expression of glucose regulated protein 94 (GRP94) during the treatment of human colorectal carcinoma cell line-Clone A cells with sodium butyrate was studied. Sodium butyrate (SB) can cause functional and morphological effects on Clone A cells including growth arrest at G0/G1 stage and cell differentiation as observed by morphological changes, MTT and flow cytometry assays, as well as reduced Grp94 gene expression as shown by Northern blot and Western blot assays. The possible mechanism of the correlation between Grp94 gene expression and tumor growth inhibition and cell differentiation is briefly discussed.

Isoporphycene: The Fourth Constitutional Isomer of Porphyrin with an N(4) Core-Occurrence of E/Z Isomerism

Liberation of the ligand from the nickel complex 1 obtained by template synthesis yielded isoporphycene (as the octaethyl derivative 2), the first constitutional isomer of porphyrin with an N(4) core for which E/Z isomerism is involved: Compound 2 is present as the E isomer, which is in rapid, presumably acid-catalyzed equilibrium with a small amount (2 %) of the Z isomer. The remaining unknown constitutional isomers of porphyrin are considerably higher in energy than the already rather labile isoporphycene, so that the latter should mark the border of existence for this type of structural variant of porphyrin.

Digital optical computing with magneto-optic spatial light modulators: a new and efficient multiplication algorithm

Digital optical computing executed on arrays of binary data can offer parallel processing and multivalued output, which permits more flexibility in algorithm development. The hardware used consists of two computer-controlled magneto-optic spatial-light-modulator arrays in conjunction with a CCD detector array as the computational hardware. Algorithms for binary-processing tasks are presented. We used magneto-optic spatial light modulators for parallel processing in a way that exploits multivalued output. Also, in carrying this evaluation out, we developed a new and efficient multiplication algorithm. Multiplication is an important operation in many digital systems, and the design of fast multipliers is of great interest to computer scientists and engineers. The speed of this computing system is evaluated.