Safety evaluation of human umbilical cord-mesenchymal stem cells in type 2 diabetes mellitus treatment: A phase 2 clinical trial

BACKGROUND

Progressive pancreatic β cell dysfunction is a fundamental aspect of the pathology underlying type 2 diabetes mellitus (T2DM). Recently, mesenchymal stem cell (MSC) transplantation has emerged as a new therapeutic method due to its ability to promote the regeneration of pancreatic β cells. However, current studies have focused on its efficacy, and there are few clinical studies on its safety.

AIM

To evaluate the safety of human umbilical cord (hUC)-MSC infusion in T2DM treatment.

METHODS

An open-label and randomized phase 2 clinical trial was designed to evaluate the safety of hUC-MSC transplantation in T2DM in a Class A hospital. Ten patients in the placebo group received acellular saline intravenously once per week for 3 wk. Twenty-four patients in the hUC-MSC group received hUC-MSCs (1 × 106 cells/kg) intravenously once per week for 3 wk. Diabetic clinical symptoms and signs, laboratory findings, and imaging findings were evaluated weekly for the 1st mo and then at weeks 12 and 24 post-treatment.

RESULTS

No serious adverse events were observed during the 24-wk follow-up. Four patients (16.7%) in the hUC-MSC group experienced transient fever, which occurred within 24 h after the second or third infusion; this did not occur in any patients in the placebo group. One patient from the hUC-MSC group experienced hypoglycemic attacks within 1 mo after transplantation. Significantly lower lymphocyte levels (weeks 2 and 3) and thrombin coagulation time (week 2) were observed in the hUC-MSC group compared to those in the placebo group (all P < 0.05). Significantly higher platelet levels (week 3), immunoglobulin levels (weeks 1, 2, 3, and 4), fibrinogen levels (weeks 2 and 3), D-dimer levels (weeks 1, 2, 3, 4, 12, and 24), and neutrophil-to-lymphocyte ratios (weeks 2 and 3) were observed in the hUC-MSC group compared to those in the placebo group (all P < 0.05). There were no significant differences between the two groups for tumor markers (alpha-fetoprotein, carcinoembryonic antigen, and carbohydrate antigen 199) or blood fat. No liver damage or other side effects were observed on chest X-ray.

CONCLUSION

Our study suggested that hUC-MSC transplantation has good tolerance and high safety in the treatment of T2DM. It can improve human immunity and inhibit lymphocytes. Coagulation function should be monitored vigilantly for abnormalities.

[Investigate of the etiology and prevention status of liver cirrhosis]

Objective: To investigate the etiology, prevention and treatment status, and their corresponding regional differences of the patients with liver cirrhosis in China, in order to provide scientific basis for the development of diagnosis and control strategies in China. Methods: Clinical data of patients diagnosed with liver cirrhosis for the first time through January 1, 2018 to December 31, 2020 from 50 hospitals in seven different regions of China were collected and analyzed retrospectively, and the difference of etiology, treatment, and their differences in various regions were analyzed. Results: A total of 11 861 cases with liver cirrhosis were included in the study. Thereinto, 5 093 cases (42.94%) were diagnosed as compensated cirrhosis, and 6 768 cases (57.06%) had decompensated cirrhosis. Notably, 8 439 cases (71.15%) were determined as chronic hepatitis B-caused cirrhosis, 1 337 cases (11.27%) were alcoholic liver disease, 963 cases (8.12%) were chronic hepatitis C, 698 cases (5.88%) were autoimmune liver disease, 367 cases (3.09%) were schistosomiasis, 177 cases (1.49%) were nonalcoholic fatty liver, and 743 cases (6.26%) of other types of liver disease. There were significant differences in the incidence of chronic hepatitis B, chronic hepatitis C, alcoholic liver disease, fatty liver, schistosomiasis liver disease, and autoimmune liver disease among the seven regions (P<0.001). Only 1 139 cases (9.60%) underwent endoscopic therapy, thereinto, 718 cases (6.05%) underwent surgical therapy, and 456 cases (3.84%) underwent interventional therapy treatment. In patients with compensated liver cirrhosis, 60 cases (0.51%) underwent non-selective β receptor blockers(NSBB), including 59 cases (0.50%) underwent propranolol and 1 case (0.01%) underwent carvedilol treatment. In patients with decompensated liver cirrhosis, 310 cases (2.61%) underwent NSBB treatment, including 303 cases (2.55%) underwent propranolol treatment and 7 cases (0.06%) underwent carvedilol treatment. Interestingly, there were significant differences in receiving endoscopic therapy, interventional therapy, NSBB therapy, splenectomy and other surgical treatments among the seven regions (P<0.001). Conclusion: Currently, chronic hepatitis B is the main cause (71.15%) of liver cirrhosis in several regions of China, and alcoholic liver disease has become the second cause (11.27%) of liver cirrhosis in China. The three-level prevention and control of cirrhosis in China should be further strengthened.

Observation of a Strongly Isospin-Mixed Doublet in ^{26}Si via β-Delayed Two-Proton Decay of ^{26}P

β decay of proton-rich nuclei plays an important role in exploring isospin mixing. The β decay of ^{26}P at the proton drip line is studied using double-sided silicon strip detectors operating in conjunction with high-purity germanium detectors. The T=2 isobaric analog state (IAS) at 13 055 keV and two new high-lying states at 13 380 and 11 912 keV in ^{26}Si are unambiguously identified through β-delayed two-proton emission (β2p). Angular correlations of two protons emitted from ^{26}Si excited states populated by ^{26}P β decay are measured, which suggests that the two protons are emitted mainly sequentially. We report the first observation of a strongly isospin-mixed doublet that deexcites mainly via two-proton decay. The isospin mixing matrix element between the ^{26}Si IAS and the nearby 13 380-keV state is determined to be 130(21) keV, and this result represents the strongest mixing, highest excitation energy, and largest level spacing of a doublet ever observed in β-decay experiments.

[Consecutive 4-year Elevated Atmospheric CO2 on Shaped Microbial Communities in the Rhizosphere Soil of Robinia pseudoacacia L. Seedlings Grown in Pb-contaminated Soils]

Elevated atmospheric CO₂ could affect the speciation of heavy metals in rhizosphere soils by changing root exudates, thereby influencing soil microecosystem in the rhizosphere. Therefore, understanding the function of heavy metals in soils on rhizospheric ecology under elevated atmospheric CO₂ scenarios is highly important. Here, we investigated the combined effects of a four-year period of elevated air CO₂ concentrations[(700±27) μmol·L^-1] and Pb-contamination (15.6 mg·kg^-1 and 515.6 mg·kg^-1) on the soil rhizopheric microbial community of Robinia pseudoacacia L. seedlings. Significant (P<0.05) effects of CO₂, Pb, and their interaction on bacterial richness and fungal diversity were observed. Relative to Pb exposure alone, elevated CO₂ significantly increased pH, total C, total N, and water-soluble organic carbon, and the C/N ratio under Pb exposure (P<0.05) and significantly decreased total and soluble Pb content (P<0.05). The richness and diversity of bacteria increased (P<0.05), fungal richness decreased (P<0.05), and microbial diversity increased (P<0.05) under the combined treatments relative to Pb contamination alone. The changes in the relative abundance of the top two dominant bacterial and fungal genera were not significant; however, differences in the relative abundances of other groups, such as Anaerolineaceae, Solirubrobacterales, Eurotiomycetes, Aspergillus, and Trichocomaceae, were significant between the different treatments. According to a redundancy analysis, total C and soluble Pb had a significant influence (P<0.05) on the dominant bacterial genera, and total C affected (P<0.05) the dominant genera in the fungal community. These results suggest that the responses of soil environmental factors to the combination of elevated atmospheric CO₂ and Pb could shape soil microbial community structure in the rhizosphere of R. pseudoacacia seedlings.

Oreocharis flavovirens, a new species of Gesneriaceae from Southern Gansu Province, China

Oreocharis flavovirens is a new species of Gesneriaceae from Gansu, China and is described and illustrated here. It is morphologically similar to O. glandulosa, O. humilis and O. farreri, but those congeners of this new taxon can be distinguished by several salient characters. A description of O. flavovirens, together with illustrations and photos, are presented.

[The rotational stability of Toric intraocular lenses and influencing factors in cataract patients with different axial length]

Objective: To evaluate the rotational stability of the Toric intraocular lens (TIOL) and influencing factors in cataract patients with different axial length. Methods: This retrospective cohort study consecutively enrolled patients who had phacoemulsification and AcrySof TIOL implantation in Peking University Third Hospital from May 2018 to January 2019. Based on axial length, patients were divided into two groups. Group A consisted of patients whose axial length was ≤ 24 mm. Patients whose axial length was >24 mm were included in group B. Data at three months postoperatively were used to evaluate the rotational stability of TIOL and its correlation with axial length, corneal white to white distance, lens thickness and TIOL spherical power. And t test, nonparametric test, chi-square test and Spearman test were used for statistical analysis. Results: Group A enrolled 39 patients (17 males and 22 females), with a median age of 74 years (range, 36-86 years). Group B enrolled 26 patients (11 males and 15 females), with a median age of 68 years (range, 36-86 years). For the efficacy of TIOL, in group A, the best corrected distance visual acuity (BCDVA, logarithm of the minimum angle of resolution) was 0.30 (0.10, 1.00) preoperatively and 0.10 (0.00, 0.60) postoperatively, and the astigmatism was 2.11 (0.95, 5.10) D preoperatively and 1.00 (0.00, 1.75) D postoperatively. In group B, the BCDVA was 0.36 (0.05, 1.00) preoperatively and 0.05 (0.00, 0.40) postoperatively, and the astigmatism was 2.00 (0.78, 3.76) D preoperatively and 0.75 (0.00, 2.25) D postoperatively. Between group A and group B, there were no significant differences in BCDVA (P=0.604) and astigmatism (P=0.789) preoperatively.In these two groups, postoperative BCDVA and astigmatism both significantly improved compared to preoperative parameters (both P<0.01). Between group A and group B, there were no significant differences in BCDVA (P=0.536) and astigmatism (P=0.076) postoperatively. In terms of rotational stability, the rotation in group A was 5.15°±3.62°, and that in group B was 6.50°±4.66°. There was no statistical difference between two groups (P=0.195). As for predictability, the percentage of eyes with rotation ≤5° was 59.0% (23 eyes) in group A and 50.0% (13 eyes) in group B. There was no statistical difference between the two groups (P=0.647). There was no significant correlation between the rotational stability of TIOL and axial length, corneal white to white distance, lens thickness or TIOL spherical power (P=0.836, 0.568, 0.170, 0.365). Conclusions: The rotational stability of TIOL at three months postoperatively in patients whose axial length >24 mm is of no difference with patients whose axial length ≤ 24 mm. It has no correlation with axial length, corneal white to white distance, lens thickness and TIOL spherical power. (Chin J Ophthalmol, 2020, 56: 41-46).

[Impact of cessation of antiviral therapy at delivery on postpartum liver function in mothers with chronic hepatitis B virus infection]

Objective: To investigate the impact of immediate cessation of antiviral therapy on postpartum liver function and the factors influencing postpartum abnormality in mothers with chronic hepatitis B virus infection. Methods: A retrospective cohort study was conducted. One hundred eighty-eight pregnant women with HBV DNA level > 2×106 IU/ml were enrolled from June 2014 to June 2018. Demographic information and clinical data of liver function and HBV DNA load during gravidity, intrapartum and postpartum period were collected. According to the antiviral treatment recommendations during pregnancy, the women were divided into three groups, namely, tenofovir (TDF), telbivudine (LdT) and control group. Liver function abnormalities among the three groups were compared within 6 months after delivery, and the factors influencing abnormal liver function were analyzed by unconditional logistic regression. Results: Of the 188 cases, 72 cases were in the TDF group, 80 cases in the LdT group, and 36 cases in the control group. Pregnant women in the TDF and LdT groups received oral TDF (300 mg/d) and LdT (600 mg/d) from 28 ± 4 weeks of gestation till delivery. Among the 188 patients, 30 (16.0%) had abnormal postpartum liver function abnormality. The incidence of postpartum liver function abnormality [alanine aminotransferase (ALT) > 2 × upper limit of normal (ULN)] in the TDF, LdT, and control groups was 19.4%, 12.5%, and 16.7%, respectively. The postpartum peak levels of ALT (median, range) in the three groups were 34.5 (12.0-946.0) U/L, 37.5 (12.0-733.8) U/L, and 39.0 (7.0-513.0) U/L, respectively. There was no significant difference between the two indexes among the three groups (P > 0.05). There was no statistically significant difference in the degree of postpartum liver function abnormalities between the three groups (P = 0.944). Most of the liver function abnormalities were mild to moderate (2 × ULN≤ALT < 10 × ULN), and usually resolved spontaneously or by treatment. Univariate and multivariate analysis showed that baseline ALT level during pregnancy was an independent factor associated with postpartum liver function abnormality (OR = 1.031, CI 95%: 1.005-1.058; χ(2) = 5.340, P = 0.021), whereas age, antiviral therapy, HBeAg-positivity, baseline HBV DNA levels, gravidity, parity, preterm delivery and delivery mode were not significantly associated with postpartum liver function abnormality. Conclusion: Cessation of antiviral therapy after delivery did not significantly increase the risk of postpartum liver function abnormality in pregnant women with chronic HBV infection. The ALT level during pregnancy is a factor influencing postpartum liver function abnormality.

Long non-coding RNA PICART1 suppresses proliferation and promotes apoptosis in lung cancer cells by inhibiting JAK2/STAT3 signaling

Lung cancer remains the most common cause of tumor-related death worldwide. Recent studies have revealed that long non-coding RNAs (lncRNAs) are involved in the development of various cancers, including lung cancer. This study aimed to investigate the effect and the molecular basis of lncRNA PICART1 on lung cancer. We first assessed the PICART1 expression in lung cancer in vitro and vivo by qRT-PCR. Then the expression of PICART1 in SPC-A-1 and NCI-H1975 cell lines was inhibited and overexpressed by transient transfections. Thereafter, cell viability, cell cycle, migration and apoptosis were respectively measured by MTT, Transwell and flow cytometry assay. Furthermore, qRT-PCR and western blot analysis were mainly performed to assess the expression levels of apoptosis- and migration-related proteins and JAK2/STAT3 pathway proteins. Tumor formation was measured by xenograft tumor model assay in vivo. PICART1 expression was down-regulated in human lung cancer tissues and cell lines. Knockdown of PICART1 increased cell viability of lung cancer cell lines. However, PICART1 overexpression inhibited cell cycle progression and promoted apoptosis in SPC-A-1 and NCI-H1975 cell lines. PICART1 overexpression also inhibited migration, as evidenced by up-regulation of E-cadherin, and down-regulation of Twist1, MMP2 and MMP9. Furthermore, we found PICART1 inhibition may regulate cell apoptosis and migration through activating JAK2/STAT3 pathway. In vivo experiments revealed that PICART1 knockdown significantly promoted tumor formation. This study demonstrates that PICART1 overexpression represents an anti-growth and anti-metastasis role in lung cancer cells. Additionally, PICART1 acts as a tumor suppressor may be via regulation of JAK2/STAT3 pathway.

[The establishment of the immortalized mouse brain microvascular pericytes model and its preliminary application in screening of cerebrovascular toxicants]

Objective: To establish the immortalized mouse brain microvascular pericytes model and to apply to the cerebrovascular toxicants screening study. Methods: Brain pericytes were isolated from 3 weeks of mice by tissue digestion. Immortalized pericyte cell line was constructed by infecting with LT retrovirus. Monoclone was selected to purify the immortalized pericyte cell line. The pericyte characteristics and purity were explored by immunocytochemistry. Cell proliferation was measured by using the Pomega MTS cell Proliferation Colorimetric Assay Kit. Pericytes were treated with 0, 160, 320, 640, 1 280, 2 560 μmol/L lead acetate, 0, 5, 10, 20, 40, 80 μmol/L cadmium chloride and 0, 5, 10, 20, 40, 80 μmol/L sodium arsenite in 24 hours. Cell toxicity of each group was determined by MTS assay, median lethal dose (LD(50)) was calculated in linear regression. Results: Mouse brain pericytes were successfully isolated by tissue separation and enzyme digestion method. After immortalized by LT retroviruses, monoclone was selected and expanded to establish pericyte cell line. The brain pericytes exhibited typical long spindle morphology and positive staining for α-SMA and Vimentin. The proliferation of brain pericytes cell lines was very slowly, and the doubling time was about 48 hours. The proliferation of immortalized brain pericytes cell lines was very quickly, and the doubling time was about 24 hours. After lead acetate, cadmium chloride and sodium arsenite treatment for 24 hours respectively, gradual declines in cell viability were observed. The LD(50) of lead acetate was 2 025.0 μmol/L, the LD(50) of cadmium chloride was 36.6 μmol/L, and the LD(50) of sodium arsenite was 33.2 μmol/L. Conclusion: The immortalized mouse brain microvascular pericyte model is established successfully by infecting with LT retrovirus, and can be applied to screen cerebrovascular toxicants. The toxicity of these toxicants to immortalized mouse brain microvascular pericyte is in sequence: sodium arsenite,cadmium chloride, lead acetate.

Sudden-onset unilateral ptosis induced by pituitary Macroadenoma, with false-positive jolly and neostigmine tests

The development of ptosis as a consequence of pituitary tumor is an exceptionally rare occurrence. Here, we describe the case of sudden-onset unilateral ptosis induced by pituitary macroadenoma. The condition was characterized by false-positive Jolly and neostigmine tests. These findings mimic oculomotor nerve palsy and make the correct diagnostics rather challenging. The case points to the fact that patients with acquired ptosis need detailed neuroophthalmological examination.

Brain injury in combination with tacrolimus promotes the regeneration of injured peripheral nerves

Both brain injury and tacrolimus have been reported to promote the regeneration of injured peripheral nerves. In this study, before transection of rat sciatic nerve, moderate brain contusion was (or was not) induced. After sciatic nerve injury, tacrolimus, an immunosuppressant, was (or was not) intraperitoneally administered. At 4, 8 and 12 weeks after surgery, Masson's trichrome, hematoxylin-eosin, and toluidine blue staining results revealed that brain injury or tacrolimus alone or their combination alleviated gastrocnemius muscle atrophy and sciatic nerve fiber impairment on the experimental side, simultaneously improved sciatic nerve function, and increased gastrocnemius muscle wet weight on the experimental side. At 8 and 12 weeks after surgery, brain injury induction and/or tacrolimus treatment increased action potential amplitude in the sciatic nerve trunk. Horseradish peroxidase retrograde tracing revealed that the number of horseradish peroxidase-positive neurons in the anterior horn of the spinal cord was greatly increased. Brain injury in combination with tacrolimus exhibited better effects on repair of injured peripheral nerves than brain injury or tacrolimus alone. This result suggests that brain injury in combination with tacrolimus promotes repair of peripheral nerve injury.

Substrate co-doping modulates electronic metal-support interactions and significantly enhances single-atom catalysis

Transitional metal nanoparticles or atoms deposited on appropriate substrates can lead to highly economical, efficient, and selective catalysis. One of the greatest challenges is to control the electronic metal-support interactions (EMSI) between the supported metal atoms and the substrate so as to optimize their catalytic performance. Here, from first-principles calculations, we show that an otherwise inactive Pd single adatom on TiO₂(110) can be tuned into a highly effective catalyst, e.g. for O₂ adsorption and CO oxidation, by purposefully selected metal-nonmetal co-dopant pairs in the substrate. Such an effect is proved here to result unambiguously from a significantly enhanced EMSI. A nearly linear correlation is noted between the strength of the EMSI and the activation of the adsorbed O₂ molecule, as well as the energy barrier for CO oxidation. Particularly, the enhanced EMSI shifts the frontier orbital of the deposited Pd atom upward and largely enhances the hybridization and charge transfer between the O₂ molecule and the Pd atom. Upon co-doping, the activation barrier for CO oxidation on the Pd monomer is also reduced to a level comparable to that on the Pd dimer which was experimentally reported to be highly efficient for CO oxidation. The present findings provide new insights into the understanding of the EMSI in heterogeneous catalysis and can open new avenues to design and fabricate cost-effective single-atom-sized and/or nanometer-sized catalysts.

Hypoglycemic effect of D-chiro-inositol in type 2 diabetes mellitus rats through the PI3K/Akt signaling pathway

In this investigation, a model of type 2 diabetes mellitus (T2DM) was used on Sprague-Dawley (SD) rats to clarify more details of the mechanism in the therapy of T2DM. D-chiro-inositol (DCI) was administrated to the diabetic rats as two doses [30, 60 mg/(kg·body weight·day)]. The biochemical indices revealed that DCI had a positive effect on hypoglycemic activity and promoted the glycogen synthesis. The rats in DCI high-dosage group had a blood glucose reduction rate of 21.5% after 5 weeks of treatment, and had insulin content in serum about 15.3 ± 2.37 mIU/L which was significantly decreased than diabetes control group. Real-time polymerase chain reaction (RT-PCR) results revealed that DCI gave a positive regulation on glycogen synthase (GS) and protein glucose transporter-4 (Glut4). Western blotting suggested that DCI could up-regulated the expression of the phosphatidylinositol-3-kinase (PI3K) p85, PI3Kp110, GS as well as the phosphorylation of protein kinase B (Akt) both in the liver and the skeletal muscle. The results also revealed that DCI enhanced the Glut4 expression on skeletal muscle. Above all, DCI played a positive role in regulating insulin-mediated glucose uptake through the PI3K/Akt signaling pathway in T2DM rats.

The longitudinal epineural incision and complete nerve transection method for modeling sciatic nerve injury

Injury severity, operative technique and nerve regeneration are important factors to consider when constructing a model of peripheral nerve injury. Here, we present a novel peripheral nerve injury model and compare it with the complete sciatic nerve transection method. In the experimental group, under a microscope, a 3-mm longitudinal incision was made in the epineurium of the sciatic nerve to reveal the nerve fibers, which were then transected. The small, longitudinal incision in the epineurium was then sutured closed, requiring no stump anastomosis. In the control group, the sciatic nerve was completely transected, and the epineurium was repaired by anastomosis. At 2 and 4 weeks after surgery, Wallerian degeneration was observed in both groups. In the experimental group, at 8 and 12 weeks after surgery, distinct medullary nerve fibers and axons were observed in the injured sciatic nerve. Regular, dense myelin sheaths were visible, as well as some scarring. By 12 weeks, the myelin sheaths were normal and intact, and a tight lamellar structure was observed. Functionally, limb movement and nerve conduction recovered in the injured region between 4 and 12 weeks. The present results demonstrate that longitudinal epineural incision with nerve transection can stably replicate a model of Sunderland grade IV peripheral nerve injury. Compared with the complete sciatic nerve transection model, our method reduced the difficulties of micromanipulation and surgery time, and resulted in good stump restoration, nerve regeneration, and functional recovery.

Associations between body mass index and maternal weight gain on the delivery of LGA infants in Chinese women with gestational diabetes mellitus

BACKGROUND

Women with gestational diabetes mellitus (GDM) are at increased risk for maternal and fetal complications including delivery of large for gestational age (LGA) infants. Maternal body mass index (BMI) and excessive weight gain during pregnancy are associated with delivery of LGA infants. However, whether maternal BMI and weight gain are associated with LGA infants in women with GDM is unclear.

BASIC PROCEDURES

Data on 1049 pregnant women who developed GDM were collected from a university teaching hospital in China and retrospectively analyzed. Data included maternal BMI, weight gain, incidence of LGA and gestational week at diagnosis.

MAIN FINDINGS

The incidence of LGA infants was significantly associated with maternal BMI (p=0.0002) in women with GDM. The odds of delivery of LGA for obese or overweight pregnant women are 3.8 or 2 times more than normal weight pregnant women. The incidence of LGA infants was also significantly associated with maternal weight gain in women with GDM. The odds ratio of delivery of LGA for pregnant women with excessive weight gain was 3.3 times more than pregnant women with normal weight gain. The effect of weight gain was not significantly different between different maternal BMI.

PRINCIPAL CONCLUSION

The incidence of delivery of LGA infants in Chinese women with GDM who were overweight or obese is higher than Caucasians, Hispanic, and Asian-Americans. The effects of maternal BMI and weight gain on the delivery of LGA infants by women with GDM are additive.

Stacking principle and magic sizes of transition metal nanoclusters based on generalized Wulff construction

Nanoclusters with extra stability at certain cluster sizes are known as magic clusters with exotic properties. The classic Wulff construction principle, which stipulates that the preferred structure of a cluster should minimize its total surface energy, is often invoked in determining the cluster magicity, resulting in close-shelled Mackay icosahedronal clusters with odd-numbered magic sizes of 13, 55, 147, etc. Here we use transition metal clusters around size 55 as prototypical examples to demonstrate that, in the nanometer regime, the classic Wulff construction principle needs to be generalized to primarily emphasize the edge atom effect instead of the surface energy. Specifically, our detailed calculations show that nanoclusters with much shorter total edge lengths but substantially enlarged total surface areas are energetically much more stable. As a consequence, a large majority of the nanoclusters within the 3d-, 4d-, and 5d-transition metal series are found to be fcc or hcp crystal fragments with much lower edge energies, and the widely perceived magic size of 55 is shifted to its nearby even numbers.

A novel cytotoxic T lymphocyte epitope analogue with enhanced activity derived from cyclooxygenase-2

Cyclooxygenase-2 is a promising target for cancer immunotherapy. Here, we designed the analogues p321-9L and p321-1Y9L (YLIGETIKL) from cyclooxygenase-2-derived native peptide p321. Then, we tested the binding affinity and stability of the analogues and their ability to elicit specific immune response both in vitro (from PBMCs of HLA-A*02⁺ healthy donors) and in vivo (from HLA-A2.1/K(b) transgenic mice). Our results indicated that the activity of cytotoxic T lymphocytes induced by p321-9L and p321-1Y9L was more potent than that of p321. In conclusion, the epitope analogue, especially p321-1Y9L, may be a good candidate which could be used to the immunotherapy of patients with tumours expressing cyclooxygenase-2.

Disorder trapping during crystallization of the B2-ordered NiAl compound

Using molecular dynamics simulations, disorder trapping associated with solidification is studied for the (100), (110), and (111) growth directions in the B2 NiAl ordered alloy compound. At the high interface velocities studied we observe pronounced disorder and defect trapping, i.e., the formation of antisite defects and vacancies in the crystal at higher than equilibrium concentrations upon rapid solidification. The vacancies are located primarily on the Ni sublattice and the majority of antisite defects are Ni atoms on the Al sublattice, while the concentration of Al on the Ni sublattice is negligibly small. The defect concentration is found to increase in an approximately linear relationship with increasing the interface velocity. Further there is no significant anisotropy in the defect concentrations for different interface orientations. Our results suggest that the currently available models of disorder trapping should be extended to include both antisite defects and vacancies.

A new inducible expression system in a transformed green alga, Chlorella vulgaris

Genetic transformation is useful for basic research and applied biotechnology. However, genetic transformation of microalgae is usually quite difficult due to the technical limitations of existing methods. We cloned the promoter and terminator of the nitrate reductase gene from the microalga Phaeodactylum tricornutum and used them for optimization of a transformation system of the microalga Chlorella vulgaris. This species has been used for food production and is a promising candidate as a bioreactor for large-scale production of value-added proteins. A construct was made containing the CAT (chloramphenicol acetyltransferase) reporter gene driven by the nitrate reductase promoter. This construct was transferred into the C. vulgaris genome by electroporation. Expression of CAT in transgenic Chlorella conferred resistance to the antibiotic chloramphenicol and enabled growth in selective media. Overall efficiency for the transformation was estimated to be approximately 0.03%, which is relatively high compared with other available Chlorella transformation systems. Expression of CAT was induced in the presence of nitrate and inhibited in the presence of ammonium as a sole nitrogen source. This study presented an inducible recombinant gene expression system, also providing more gene regulation elements with potential for biotechnological applications.

Innate immune parameters and haemolymph protein expression profile to evaluate the immunotoxicity of tributyltin on abalone (Haliotis diversicolor supertexta)

The immunotoxicity of tributyltin (TBT) on marine gastropods has been comparatively little studied although risks to wildlife associated with this compound are well known. In this study, a 30-day trial was conducted to evaluate the immunotoxic effects on abalone (Haliotis diversicolor supertexta) by exposing a range of doses of TBT (0, 2, 10, and 50 ng/L). Innate immune parameters, including phagocytic ability (PA), lysozyme activity, phenoloxidase (PO) level and superoxide dismutase (SOD) activity were monitored at intervals of 5, 15 and 30 days. Haemolymph protein expression profile was also examined at the end of the experiment. The results showed that PA value, lysozyme activity and PO level significantly decreased compared with the controls (P < 0.05), which indicated that TBT exposure markedly suppressed non-specific immune competence. Exposure to TBT also caused variation in protein expression patterns of haemolymph. Among the protein spots of differential expressions, seven proteins from the haemolymph of TBT-treated abalone were successfully identified by MALDI-TOF-MS analysis. Three protein spots increased and were identified as carrier-like peptide, peroxidase 21 precursor and creatine phosphokinase. These proteins are believed to up-regulate in expression as a response to detoxification and antioxidative stress mechanisms. The other four protein spots that down-regulated in TBT-treated groups were identified as aromatase-like protein, protein kinase C, ceruloplasmin and microtubule-actin crosslinking factor 1, and these proteins play an important role in endocrine regulation and immune defense. Taken together, the results demonstrate that TBT impair abalone immunological ability and is a potential immune disruptor.

[The study of effects and mechanism of U50, 488H on electrical coupling during ischemia in the perfused isolated rat heart]

OBJECTIVE

To determine the effect of activation of lambda-opioid receptor with U50, 488H, a selective kappa-opioid receptor agonist, on the changes in electrical coupling during prolonged ischemia and to explore the possible mechanism.

METHODS

The isolated rat heart was perfused in a Langendorff apparatus. The effect of U50, 488H on electrical coupling parameters including onset of uncoupling, plateau time, slope and fold increase in r(t) was observed in isolated perfused rat heart subjected to global no-flow ischemia. The effect of U50, 488H on connexin 43 (Cx43) expression of ventricular muscle during ischemia was determined by immunohistochemistry.

RESULTS

In the prolonged ischemia model, U50, 488H concentration dependently delayed the onset of uncoupling, increased time to plateau, and decreased the maximal rate of uncoupling during ischemia. The effect of U50, 488H on electrical uncoupling parameters during ischemia was abolished by a selective kappa-opioid receptor antagonist nor-BNI or a PKC inhibitor chelerythrine. The amount of Cx43 immunoreactive signal in ventricular muscle was greatly reduced after ischemia. U50, 488H markedly increased Cx43 expression during ischemia and its effect was also attenuated by nor-BNI or chelerythrine.

CONCLUSION

These results demonstrated that U50, 488H delayed the onset of uncoupling and plateau time, decreased the maximal rate of uncoupling and increased Cx43 expression of ventricular muscle during ischemia, and these effects of U50, 488H were mediated by kappa-opioid receptor, in which activation of PKC was involved. The effect of U50, 488H on electrical coupling during ischemia was probably correlated with preservation of Cx43 in cardiac muscle.

A proteomics based approach to assessing the toxicity of bisphenol A and diallyl phthalate to the abalone (Haliotis diversicolor supertexta)

The contamination of marine ecosystems by endocrine disrupting compounds (EDCs) is of great concern. Protein expression profile maybe a good method to help us understand the molecular mechanisms of EDCs-toxicity to aquatic organisms. In this study, the abalone (Haliotis diversicolor supertexta), was selected as the target organism. Toxicological effects of two reference endocrine disruptors: diallyl phthalate (DAP, 50microgL(-1)) and bisphenol-A (BPA, 100microgL(-1)) were investigated after a three months static-renewal exposure on abalones using proteomics to analyze their hepatopancreas tissues. Some enzyme activity parameters of hepatopancreas extracts were also performed, including Na(+)-K(+)-ATPase, Ca(2+)-Mg(2+)-ATPase, peroxidase (POD) and malondialdehyde (MDA) production. After analyzing the proteomics profile of hepatopancreas by 2D gel electrophoresis, we found that 24 spots significantly increased or decreased at protein expression level (2-fold difference) in the 2D-maps from the treatment groups. Eighteen out of 24 protein spots were successfully identified by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF-MS). These proteins can be roughly categorized into diverse functional classes such as detoxification, oxidative stress, hormone regulating, cellular metabolism and innate immunity. In addition, the enzymatic results indicated that DAP/BPA exposure affected the oxidative stress status and the cellular homeostasis, which partly corroborated the proteomics' results. Taken together, these data demonstrate that proteomics is a powerful tool to provide valuable insights into possible mechanisms of toxicity of EDCs contaminants in aquatic species. Additionally, the results highlight the potential of abalone as a valuable candidate for investigating EDCs impacts on marine ecosystems.

Risk factors for anastomotic leakage after anterior resection for rectal cancer

Anastomotic leakage is a common complication after anterior resection for rectal cancer. It can increase postoperative mortality rate and local tumor recurrence rate, lower long-term survival, result in long-term impairment of anorectal function and increase patients' suffering, raise treatment costs, and prolong hospital stay. A better understanding of the risk factors for AL has important clinical implications for the management of such complication.

Surface precipitation of highly porous hydrotalcite-like film on Al from a zinc aqueous solution

A hydrotalcite-like film has been successfully deposited on an Al-bearing glass substrate based on an interface reaction between an Al layer and a zinc aqueous solution. The film selectively grew on the Al surface but not on the glass surface. The film on Al was composed of layered nanosheets of a hydrotalcite-like compound containing Al and Zn. Comparably, deposits on the plastic surface and precipitates in solution were wurzite-type ZnO with various morphologies depending upon the preparation conditions. At low supersaturation degrees, single crystals and superstructures of Zn-Al hydrotalcite were also obtained. This porous hydrotalcite film has a potential application as catalyst supports, environmental materials, or matrixes for hydrotalcite-based nanocomposite films. Using Al as a reaction interface makes it easy to coat porous hydrotalcites on a series of matrix materials varying in shapes and properties, which is important for achieving practical applications. In addition, the method developed should be widely applicable to other systems for the preparation of porous or oriented hydrotalcite-like thin films by an appropriate combination of divalent/trivalent solution-substrate systems.

[Rapid induction of senescence-like changes in human umbilic vein endothelial cells(HUVECs) by C6 ceramide]

Ceramide, a key molecule in sphingolipid metabolism and a candidate second messenger, has been shown to inhibit the activity of phospholipase D. This biochemical pathway has been implicated to regulate cell differentiation, apoptosis and cellular senescence. Ceramide is generated in response to a number of extracellular inducers(for example: TNF, IL-1 and Fas ligands etc.), and acts as a second messenger to mediate many of the effects of these inducers. HUVECs are the monolayer cells located inside the vein wall and play an important role in the regulation of vein physiology and blood function. It has been reported that the C6 ceramide can induce senescence of WI-38 HDF and promote the activity of beta-galactosidase, but, C2 ceramide has no such effect. In this study, we investigated the role of C6 ceramide in the senescence of HUVECs. 10 mumol/ml of C6 ceramide treatment for more than 72 hours can induce morphological alterations (such as: enlarged, flattened and irregular cell body), cell cycle arrested at G1 phase and the expression of the senescent histochemical marker-beta-galactosidase in HUVECs. These results showed that C6 ceramide could induce senescence-like changes of HUVECs. The detection of reactive oxygen species(ROS) and the anti-oxidative ability of the cells showed that the C6 ceramide induced senescence-like cells still have normal ability of anti-oxidation. Further investigations are ongoing.

[Misdiagnosis of malignant lymphoma--report of 45 patients]

A series of 50 patients with malignant lymphoma, proven by biopsy, was retrospectively studied. 39 were non-Hodgkin's lymphoma and 11 Hodgkin's disease. 45 (90%) had been misdiagnosed because of lack of initial specific symptoms. It is suggested that for patients with a painless progressively enlarging superficial lymph node without adhering to its surrounding tissues and irresponsive to general management, having irregular fever, bloody stool, abdominal pain or mass, complication of partial intestinal obstruction, sharp vigilance be kept for the possibility of malignant lymphoma.

[Immune adherence (C3b) receptor activity of erythrocytes in patients with esophageal cancer and cancer of the gastric cardia]

The red cell C3b receptor activity of 52 patients with esophageal cancer, 19 patients with cancer of gastric cardia and 31 age-matched normal persons was studied by the ability of forming ZC3b-rosette (rosette formation with zymosan particles treated by guinea pig complement) and IC-Z rosette (rosette formation with zymosan particles). The results showed that the ZC3b-rosette formation rate was significantly lower in cancer patients than that of the normal subjects (P less than 0.01), but the IC-Z rosette formation rate was significantly higher in the cancer patients (P less than 0.01). This suggests that the esophageal cancer and cancer of gastric cardia be associated with surface changes in the erythrocytes, especially those of the receptors which are responsible for immune adherence reaction. The methods of detecting the red cell C3b receptor are also described.