A simple and convenient model combining multiparametric MRI and clinical features to predict tumour-infiltrating lymphocytes in breast cancer

AIM

To develop a simple and convenient method based on multiparametric magnetic resonance imaging (MRI) and clinical features to non-invasively predict tumour-infiltrating lymphocytes (TILs) in breast cancer (BC) and to explore the relationship between TIL levels and disease-free survival (DFS).

MATERIALS AND METHODS

A total of 172 BC patients were enrolled between November 2017 and June 2021 in this retrospective study. The patients were divided into high (≥10%) and low (<10%) TIL groups. Clinicopathological data were collected. MRI features were reviewed by two radiologists. Predictors associated with TILs were determined by using multivariable logistic regression analyses. Kaplan-Meier survival curves based on TIL levels were used to estimate DFS.

RESULTS

A total of 102 patients with low TILs and 70 patients with high TILs were included in the study. Tumour size (odds ratio [OR], 1.040; 95% confidence interval [CI]: 1.006, 1.075; p=0.020), apparent diffusion coefficient (ADC; OR, 1.003; 95% CI: 1.001, 1.005; p=0.015), clinical axillary lymph node status (CALNS; OR, 3.222; 95% CI: 1.372,7.568; p=0.007), and enhancement pattern (OR, 0.284; 95% CI: 0.143, 0.563; p<0.001) were independently associated with TIL levels. These features were used in the ALSE model (where A is ADC, L is CALNS, S is size, and E is enhancement pattern). High TILs were associated with better DFS (p=0.016).

CONCLUSION

The ALSE model derived from multiparametric MRI and clinical features could non-invasively predict TIL levels in BC, and high TILs were associated with longer DFS, especially in human epidermal growth factor receptor 2 (HER2)-positive BC and triple-negative BC (TNBC).

Triple-negative breast cancer: predictive model of early recurrence based on MRI features

AIM

To develop an integrated model based on preoperative magnetic resonance imaging (MRI) features for predicting early recurrence in patients with triple-negative breast cancer (TNBC).

MATERIALS AND METHODS

Women with TNBC who underwent breast MRI and surgery between 2009 and 2019 were evaluated retrospectively. Two breast radiologists reviewed MRI images independently based on the Breast Imaging Reporting and Data System Lexicon (BI-RADS), and classified the breast oedema scores on T2-weighted imaging (WI) as no oedema, peritumoural oedema, prepectoral oedema, or subcutaneous oedema. The relationship between disease-free survival (DFS) and MRI features was analysed by Cox regression, and a nomogram model was generated based on the results.

RESULTS

150 patients with TNBC were included and divided into a training cohort (n=78) and validation cohort (n=72). MRI features including subcutaneous oedema and rim enhancement showed a tendency to worsen DFS in univariate analysis. Multivariate analysis showed that subcutaneous oedema (p=0.049, HR [95% confidence interval {CI} = 8.24 [1.01-67.52]) and rim enhancement (p=0.016, HR [95% CI] = 4.38 [1.32-14.54]) were independent predictors for DFS. In the nomogram, the areas under the curves (AUCs) of the training cohort was 0.808, and that of the validation cohort was 0.875.

CONCLUSION

The presence of subcutaneous oedema or rim enhancement on preoperative breast MRI was shown to be a good predictor of poor survival outcomes in patients with TNBC.

LINC01255 combined with BMI1 to regulate human mesenchymal stromal senescence and acute myeloid leukemia cell proliferation through repressing transcription of MCP-1

BACKGROUND

Long non-coding RNAs (lncRNAs) govern fundamental biochemical and cellular biology processes, for example, participate in chromatin remodeling, imprinting, splicing, transcriptional regulation and translation. Dysregulation of lncRNA expression is act as a feature of various diseases and cancers, including hematopoietic malignancies. However, the clinical relevance of myelodysplastic syndrome (MDS) and acute myeloid leukemia preceded by MDS (MDS-AML) requires further research. Recently, lncRNAs have been demonstrated, which play an important role in hematopoiesis, thus, to further finding more functional lncRNA seemed particularly important.

METHODS

Western blotting, real-time PCR, RNA-pulldown, RIP (RNA immunoprecipitation), Chromatin immunoprecipitation (ChIP), cellular compartments extraction assays, SA-β-gal staining, lentivirus transfection, cell viability assay and cell proliferation assays were used to examine the relationship between lncRNA LINC01255 and its regulation of p53-p21 pathway in human mesenchymal stromal and acute myeloid leukemia cells.

RESULTS

LncRNA LINC01255 is highly expressed in bone marrow cells of AML patients, CD34+ cells of MDS-AML patients and AML cell lines and the higher expression of LINC01255 is associated with poor survival rate of AML patients. LINC01255 can interact with BMI1 and repress the transcription of MCP-1 to active p53-p21 pathway, thus inhibiting the senescence of human mesenchymal stromal and proliferation of acute myeloid leukemia cell.

CONCLUSIONS

We discovered a novel functional lncRNA LINC01255, which can regulate the senescence of human mesenchymal stromal and the proliferation of acute myeloid leukemia cell through inhibiting the transcription of MCP-1.

Risk of SARS-CoV-2 infection among contacts of individuals with COVID-19 in Hangzhou, China

Objectives

This study determined the rate of secondary infection among contacts of individuals with confirmed coronavirus disease 2019 (COVID-19) in Hangzhou according to the type of contacts, the intensity of contacts, and their relationship with the index patient.

Study design

This is a retrospective cohort study.

Methods

The analysis used the data of 2994 contacts of 144 individuals with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The contacts were categorized according to the information source, type of contact, location, intensity of contact, and relationship with the index patient.

Results

The incidence of infection differed significantly according to contact type. Of the contacts, 186 (6.2%) developed symptoms, and 71 (2.4%) had confirmed SARS-CoV-2 infection. The main symptoms were cough and fever. Compared with those who had brief contact with the index case, those who had dined with the index case had 2.6 times higher risk of acquiring infection; those who had shared transport with, had visited, or had contact with the index case in a medical institution had 3.6 times higher risk of acquiring infection; and household contacts had 41.7 times higher risk of acquiring infection. Family members had 31.6 times higher risk of acquiring infection than healthcare providers or other patients exposed to an index case.

Conclusions

The form and frequency of contact are the main factors affecting the risk of infection among contacts of individuals with COVID-19. Centralized isolation and observation of close contacts of individuals with confirmed SARS-CoV-2 infection, in addition to population-based control measures, can reduce the risk of secondary infections and curb the spread of the infection.

•

The incidence of infection differed significantly according to contact type.

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Contact form and frequency are important to the risk of COVID-19.

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Centralized isolation and observation of contacts curbed the spread of the infection.

Efficacy of combination therapy with ezetimibe and statins versus a double dose of statin monotherapy in participants with hypercholesterolemia: a meta-analysis of literature

Background

The aim of this study was to compare and summarize the lipid-altering effects of combination therapy with ezetimibe and statins (E/S) and a double dose of statin (D/S) monotherapy on patients with hypercholesterolemia.

Methods

We conducted search on 2 medical databases, PubMed and EMBASE to identify all relevant studies. A meta-analysis was performed to clarify the efficacy in the two groups. Only double-blind Randomized controlled study (RCTs) of efficacy evaluation in the two groups with ezetimibe and statins and a double dose of statin in participants with hypercholesterolemia that examined low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) and high-density lipoprotein (HDL) were included. Two reviewers extracted data from all primary studies independently. The primary data were the level of LDL-C, TC and HDL-C concentrations at the end point and are expressed as mean and standard deviation (SD).

Results

A total of 11 double-blind, active or placebo-controlled studies with 1926 hypercholesterolemia adults randomized to ezetimibe 10 mg added to ongoing statins (N = 994) or statin titration (doubling) (N = 932) were pooled for the global meta-analysis. The effect size between treatment groups within individual studies was assessed by weighted mean difference (MD) using a random- or fixed-effect model. The result showed that the participants in E/S group get obvious lower LDL-C [MD = -13.14 mg/dL, 95%CI (−16.83, -9.44), p = 0.00001] and TC concentration [MD = -23.79 mg/dL, 95%CI (−38.65, -8.93), p = 0.002] from baseline to follow-up, comparing to the D/S group. Besides, no significant between-group differences were observed for concentrations of HDL-C [MD = 0.46 mg/dL, 95%CI (− 1.14, 2.06), p = 0.57]. According to subgroup analysis, the combination of ezetimibe and atorvastatin (10 mg) [MD = -16.98 mg/dL, p < 0 .0001] or simvastatin (20 mg) [MD = -17.35 mg/dL, p < 0 .0001] showed stronger ability of reducing LDL-C than combination of ezetimibe and rosuvastatin (10 mg) [MD = -9.29 mg/dL, p = 0.05]. The efficacy of short-term (endpoint time between 6 to 16 week) and long-term (52 week) treatment in the LDL-C between two groups did not show significant differences. Besides, only participants from Asia treated with combination therapy were associated with a significant lower LDL-C concentration [MD = -14.7 mg/dL, p < 0 .0001].

Conclusions

The addition of ezetimibe to statin appears to be more effective on reducing LDL-C and TC concentrations than doubling the statin dose. Moreover, the ability to reduce cholesterol levels of combinations therapy with ezetimibe and different statins or to participants from different geographic location may vary, based on this meta-analysis, while more samples are needed to verify.

[Persistence of immune memory and its related factors at 12 years after hepatitis B vaccination among adults]

Objective: To estimate the immune memory at 12 years after hepatitis B vaccination and its risk factors among adults. Methods: The study was conducted in 20 villages of Qudi town in Jiyang county, Shandong province, China in 2003. Hepatitis B surface antigen (HBsAg), antibody against HBsAg (anti-HBs) and antibody against hepatitis B core antigen (anti-HBc) were tested for all healthy residents aged 15-40 years in these villages. Those who had no history of hepatitis B vaccination and were negative for all three indicators were divided into two groups randomly. Hepatitis B vaccine (HepB) was administrated to them on 0-6 month schedule or 0-1-6 month schedule respectively. Blood samples were obtained at one month after the last dose for each receipt and were quantitatively detected for anti-HBs. Finally a total of 629 participants completed HepB vaccination and anti-HBs testing, including 288 of two-dose group and 341 of three-dose group respectively. In 2015, an additional dose of HepB (challenge dose) was administrated to those who were negative for anti-HBs at follow-up (anti-HBs <10 mIU/ml) to evaluate the immune memory. A total of 93 blood samples, including 50 of two-dose group and 43 of three-dose group respectively, were drawn at 14 days after the challenge dose and anti-HBs was quantitatively detected. The anti-HBs geometric mean concentrations (GMCs) after the challenge dose were compared between the two groups. Multivariate linear regression model was built to find the independent risk factors associated with immune memory response (anti-HBs GMC after the challenge dose). Results: The challenge dose of HepB and post-challenge anti-HBs detection were completed among 93 participants. Totally 92 (98.92%, 92/93) participants were found holding immune memory (anti-HBs after the challenge dose was ≥10 mIU/ml). The immune memory positive rates were 100% (50/50) and 97.67% (42/43) in the two-dose group and three-dose group respectively and the corresponding anti-HBs GMC after challenge dose were 2 684.30 (95%CI: 1 721.71-4 185.08) mIU/ml and 3 527.48 (95%CI: 2 145.15-5 800.58) mIU/ml (P=0.410). The anti-HBs GMC after the challenge dose were 1 908.33 (95%CI: 1 190.01-3 060.27) mIU/ml, 4 004.20 (95%CI: 2 257.90-7 101.12) mIU/ml and 8 682.16 (95%CI: 5 813.94-12 965.36) mIU/ml among the participants whose anti-HBs titer was<4, 4-6 and 7-9 mIU/ml at follow-up, respectively (P=0.002). There was no correlation between immune schedule and anti-HBs GMC after the challenge dose; β (95%CI) was -0.07 (-0.34-0.20), P=0.601. Conclusion: The immune memory after primary hepatitis B vaccination lasted for at least 12 years among adults. The immune memory response was independently associated with ant-HBs titer at follow-up, but might be similar between 0-6 month schedule and 0-1-6 month schedule.

Effect of tricyclazole on morphology, virulence and gene expression of Aspergillus aculeatus for management of soft rot disease in peach

AIMS

Aspergillus aculeatus, a pathogen of peaches, can cause soft rot and lead to economic losses in agricultural production. However, studies on the prevention of soft rot caused by A. aculeatus have rarely been reported. Tricyclazole (TCZ) is a fungicide that has been widely used in disease prevention of various crops but the inhibitory mechanism of TCZ on A. aculeatus is unknown. Our aim was to determine the effects of TCZ on A. aculeatus.

METHODS AND RESULTS

In our study, TCZ inhibited the growth of fungal colonies when applied at 0·5-6 mmol l-1 and inhibited the production of melanin at 3 mmol l-1 . Conidia exposed to TCZ were less effective at causing the disease in inoculated samples, and electrical conductivity, divulgation of nucleic acids and proteins rose with increasing concentrations of TCZ. Microscopic results suggest that TCZ damages not only the cell wall but also the cell membrane. Results of qRT-PCR showed that TCZ had no significant effect on the regulation of genes coding for laccase, apoptosis and hypothetical protein; however, it significantly down-regulated genes coding for cellulase, chitinase and sterol.

CONCLUSIONS

Tricyclazole can influence the pathogenic ability of A. aculeatus by damaging the cell structure of hyphae and conidia, reducing the melanin production, and altering the expression of pathogenic-related gene.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results explained the potential cause and mechanism TCZ produced in A. aculeatus. Our research offers scientific insights into future research interest relative to using TCZ in the treatment of soft rot caused by A. aculeatus.

A method for tracing exogenous DNA uptake in live spermatozoa and embryos

Sperm-mediated gene transfer(SMGT) is a simple method for producing transgenic animals. Due to the lack of repeatability in spermatozoa binding and internalization of exogenous DNA, the efficiency of SMGT is still low. Considering this point, the present work aims to develop a method for evaluating the spermatozoa capacity of binding exogenous DNA after co-incubation with DNA. The main approach is using a Cy5-labelled DNA to trace the exogenous DNA and assess the ability of spermatozoa to take up exogenous DNA. Using this technique, we found that the percentage of spermatozoa that are binding and uptaking DNA is higher at concentration of 10 μg/mL and 100 μg/mL than 5 μg/mL, 1 μg/mL and 0 μg/mL after incubation with Cy5-DNA for 30min at 37oC. After fertilization, the DNA fluorescence signal was also detected in zygotes in groups where spermatozoa were incubated with 10 μg/mL and 100 μg/mL of Cy5-DNA. These results showed a simple and convenient method to trace the exogenous DNA in spermatozoa and zygote when compared to conventional methods of labeling DNA during fertilization, resulting in a real-time observation of the exogenous DNA in spermatozoa and zygote.

[Prevalence of hepatitis A antibody among population covered by different hepatitis A immunization strategies in Shandong Province, 2015, China]

Objective: To evaluate prevalence of hepatitis A antibody (anti-HAV IgG) among population covered by different hepatitis A vaccine immunization strategies in Shandong Province in 2015. Methods: In October 2015, according to the geographical location of Shandong Province, the stratified random sampling method was used to stratify the 17 municipal distrcts, and the random number table method was used for sampling, First, two eastern cites (Qingdao, Rizhao), two western cities (Liaocheng, Zaozhuang) and three central cities (Jinan, Zibo and Laiwu) were selected; secondly, one county was drawn from each city. Finally, the participants were divided into five age groups including ≤7 years (age group covered by free hepatitis A vaccination strategy), 8-11 years (age group who receive hepatitis A vaccination at their own charge), 12-24 years (age group covered by catch-up vaccination of hepatitis A), 25-34 years (age group born before hepatitis A vaccine was used) and ≥35 years (age group born before hepatitis A vaccine was used). After all the paticipants or their guardians asked and registered basic information such as age, gender, home address, blood samples were collected from them and anti-HAV IgG was detected by ELISA method. The positive rate of anti-HAV IgG and 95%CI were calculated. Results: A total of 1 654 participants were involved in the final analysis, including 856 males (51.75%) and 798 females (48.25%) whose mean age was (13.44±13.06) years. The crude positive rate of anti-HAV IgG was 91.41% (1 512/1 654, 95%CI: 89.96%-92.72%) and the age-adjusted rate was 90.93% (95%CI: 90.92%-90.94%). The positive rates of anti-HAV IgG was at the highest level in the age group of ≤7 years (95.90%, 95%CI: 95.88%-95.91%) and was at the lowest level in the age group of 25-34 years (83.23%, 95%CI: 83.21%-83.25%). The age-specific positive rates of anti-HAV IgG in eastern areas (96.79%, 95%CI: 96.78%-96.80%) were higher than those in both middle areas (86.66%, 95%CI: 86.65%-86.67%) and western areas (91.96%, 95%CI: 91.95%-91.97%). Conclusion: The positive rate of anti-HAV IgG was high among the general population in Shandong Province, but relatively low among young and middle-aged adults. Besides the routine immunization of hepatitis A among the children, more efforts should be taken for the prevention and control of hepatitis A among young and middle-aged adults in Shandong Province, especially in central and western areas.

Fusion-segment of high-grade Lumbar Spondylolisthesis: 2-year follow-up

The clinical efficacy of reduction and fusion surgery and the suitable range of fusion-segment were evaluated in 12 pediatric patients treated for high-grade spondylolisthesis. Pre/post-operative clinical and radiological assessments were analyzed. A transient L5 nerve root paralysis was observed in one patient with L5 spondylolisthesis. No degenerative spondylolisthesis or adjacent segmental instability occurred above the fusion segments. In conclusion, we suggest that, in case of spondylolisthesis without severe structural scoliosis deformity or only associated with lumbosacral deformity, the posterior ligament complex should be protected in case of adjacent segmental instability and spondylolisthesis. If the spondylolisthesis is complicated with severe structural scoliosis deformity (Cobb ≥ 70°), in principle, the treatment should be performed according to the characteristics of the two diseases respectively.

A transfection method of PS-asODNs targeting ANGPTL4 in multicellular structures of hepatocarcinoma cell line

To find an efficient transfection method for metastatic cancer cells, we established a three-dimensional (3D) growth model for solid tumor cells to mimic the metastatic cancer cells in the vascular system and compared the efficiency of several transfection methods in vitro. We found that it was optimal to transfect two-dimensional cells in vitro and detach them for 3D growth 6 h later. The transfection efficiency of this method was high, and the results were reliable. This method can be used to deliver several types of small molecules into the 3D metastatic cell model. Using this method, we increased our understanding of why drugs that are effective in vitro cannot treat the disease in vivo. If this phenomenon occurs due to the resistance of the cells to the drug, other treatment agents for the disease must be identified. However, if this occurs because the agent cannot reach the cells inside the 3D aggregate, we can improve the delivery efficiency by using methods that target the agent to all cells. Briefly, the method introduced in this study will contribute to future research focusing on the 3D metastatic cell model as well as on drug development for various solid tumors.

Association between HMW adiponectin, HMW-total adiponectin ratio and early-onset coronary artery disease in Chinese population

OBJECTIVE

Adiponectin is an adipose-secreting protein that shows atheroprotective property and has inverse relation with coronary artery disease (CAD). High-molecular weight (HMW) adiponectin is reported as the active form of adiponectin. In the present study, we aimed to investigate the association between total adiponectin, HMW adiponectin, HMW-total adiponectin ratio and the severity of coronary atherosclerosis, and to compare their evaluative power for the risk of CAD.

METHODS

Serum levels of total and HMW adiponectin were measured in 382 early-onset CAD (EOCAD) patients and 305 matched controls undergoing coronary angiography by enzyme-linked immunosorbent assay (ELISA). Gensini score was used to evaluate the severity of coronary atherosclerosis.

RESULTS

CAD onset age was positively correlated with HMW adiponectin (r = 0.383, P < 0.001) and HMW-total adiponectin ratio (r = 0.429, P < 0.001) in EOCAD patients. Total and HMW adiponectin and HMW-total adiponectin ratio were all inversely correlated with Gensini score (r = -0.417, r = -0.637, r = -0.578, respectively; all P < 0.001). Multivariate binary logistic regression analysis demonstrated that HMW adiponectin and HMW-total adiponectin ratio were both inversely correlated with the risk of CAD (P < 0.05). ROC analysis indicated that areas under the ROC curves of HMW adiponectin and HMW-total adiponectin ratio were larger than that of total adiponectin (P < 0.05).

CONCLUSIONS

Adiponectin is cardioprotective against coronary atherosclerosis onset in EOCAD patients. HMW adiponectin and HMW-total adiponectin ratio show stronger negative associations with the severity of coronary atherosclerosis than total adiponectin does. HMW adiponectin and HMW-total adiponectin ratio are effective biomarkers for the risk of CAD in Chinese population.

Inhibition of eIF2α dephosphorylation enhances TRAIL-induced apoptosis in hepatoma cells

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is an inducer of cancer cell death that holds promise in cancer therapy. Cancer cells are more susceptible than normal cells to the cell-death-inducing effects of TRAIL. However, a variety of cancer cells are resistant to TRAIL through complex mechanisms. Here, we investigate the effects of inhibition of eukaryotic initiation factor 2 subunit α (eIF2α) dephosphorylation on TRAIL-induced apoptosis in hepatoma cells. Treatment of hepatoma cells with salubrinal, an inhibitor of eIF2α dephosphorylation, enhances TRAIL-induced eIF2α phosphorylation, CCAAT/enhancer-binding protein homologous protein (CHOP) expression and caspase activation. Salubrinal enhances TRAIL-induced apoptosis, which could be abrogated by caspase inhibitor. Overexpression of phosphomimetic eIF2α (S51D) enhances TRAIL-induced CHOP expression, caspase 7 and PARP cleavage and apoptosis. By contrast, overexpression of phosphodeficient eIF2α (S51A) abrogates the stimulation of TRAIL-induced apoptosis by salubrinal. Moreover, knockdown of growth arrest and DNA damage-inducible protein 34 (GADD34), which recruits protein phosphatase 1 to dephosphorylate eIF2α, enhances TRAIL-induced eIF2α phosphorylation, CHOP expression, caspase activation and apoptosis. Furthermore, the sensitization of hepatoma cells to TRAIL by salubrinal is dependent on CHOP. Knockdown of CHOP abrogates the stimulation of TRAIL-induced caspase activation and apoptosis by salubrinal. Combination of salubrinal and TRAIL leads to increased expression of Bim, a CHOP-regulated proapoptotic protein. Bim knockdown blunts the stimulatory effect of salubrinal on TRAIL-induced apoptosis. Collectively, these findings suggest that inhibition of eIF2α dephosphorylation may lead to synthetic lethality in TRAIL-treated hepatoma cells.

Hypoxia differentially regulates human nucleus pulposus and annulus fibrosus cell extracellular matrix production in 3D scaffolds

OBJECTIVE

We hypothesize that intervertebral disc (IVD) cells from distinct region respond differently to oxygen environment, and that IVD cells from patients with disc degeneration can benefit from hypoxia condition. Therefore, we aimed to determine the transcriptional response and extracellular matrix (ECM) production of nucleus pulposus (NP) and annulus fibrosus (AF) cells to different oxygen tension.

METHOD

Human NP and AF from degenerated IVD were seeded in 3D scaffolds and subjected to varying oxygen tension (2% and 20%) for 3 weeks. Changes in ECM were evaluated using quantitative real-time reverse transcriptase polymerase chain reaction, histological and immunohistological analyses.

RESULTS

Hypoxia significantly enhances NP cells phenotype, which resulted in greater production of sulfated glycosaminoglycan (GAG) and collagen type II within the constructs and the cells expressed higher levels of genes encoding NP ECM. A significantly stronger fluorescent signal for hypoxia-inducible factor (HIF-1α) as also found in the NP cells under the hypoxic than normoxic condition. However, there was little effect of hypoxia on the AF cells.

CONCLUSIONS

The NP and AF cells respond differently to hypoxia condition on the 3D scaffold, and hypoxia could enhance NP phenotype. When used in concert with appropriate scaffold material, human NP cells from degenerated disc could be regenerated for tissue engineering application.

Hypothermia protects against oxygen-glucose deprivation-induced neuronal injury by down-regulating the reverse transport of glutamate by astrocytes as mediated by neurons

Glutamate is the major mediator of excitotoxic neuronal death following cerebral ischemia. Under severe ischemic conditions, glutamate transporters can functionally reverse to release glutamate, thereby inducing further neuronal injury. Hypothermia has been shown to protect neurons from brain ischemia. However, the mechanism(s) involved remain unclear. Therefore, the aim of this study was to investigate the mechanism(s) mediating glutamate release during brain ischemia-reperfusion injury under hypothermic conditions. Neuron/astrocyte co-cultures were exposed to oxygen-glucose deprivation (OGD) at various temperatures for 2h, and cell viability was assayed 12h after reoxygenation. PI and MAP-2 staining demonstrated that hypothermia significantly decreased neuronal injury. Furthermore, [(3)H]-glutamate uptake assays showed that hypothermia protected rat primary cortical cultures against OGD reoxygenation-induced injury. Protein levels of the astrocytic glutamate transporter, GLT-1, which is primarily responsible for the clearance of extracellular glutamate, were also found to be reduced in a temperature-dependent manner. In contrast, expression of GLT-1 in astrocyte-enriched cultures was found to significantly increase following the addition of neuron-conditioned medium maintained at 37 °C, and to a lesser extent with neuron-conditioned medium at 33 °C. In conclusion, the neuroprotective effects of hypothermia against brain ischemia-reperfusion injury involve down-regulation of astrocytic GLT-1, which mediates the reverse transport of glutamate. Moreover, this process may be regulated by molecules secreted by stressed neurons.

Detection of Laribacter hongkongensis using species-specific duplex PCR assays targeting the 16S rRNA gene and the 16S-23S rRNA intergenic spacer region (ISR)

AIMS

For the rapid detection of Laribacter hongkongensis, which is associated with human community-acquired gastroenteritis and traveller's diarrhoea, we developed a duplex species-specific PCR assay.

METHODS AND RESULTS

Full-length of the 16S-23S rRNA intergenic spacer region (ISR) sequences of 52 L. hongkongensis isolates were obtained by PCR-based sequencing. Two species-specific primer pairs targeting 16S rRNA gene and ISR were designed for duplex PCR detection of L. hongkongensis. The L. hongkongensis species-specific duplex PCR assay showed 100% specificity, and the minimum detectable level was 2.1 × 10(-2) ng μl(-1) genomic DNA which corresponds to 5000 CFU ml(-1).

CONCLUSIONS

The high specificity and sensitivity of the assay make it suitable for rapid detection of L. hongkongensis.

SIGNIFICANCE AND IMPACT OF THE STUDY

This species-specific duplex PCR method provides a rapid, simple, and reliable alternative to conventional methods to identify L. hongkongensis and may have applications in both clinical and environmental microbiology.

Nuclear translocation of telomerase reverse transcriptase: a critical process in chemical induced hepatocellular carcinogenesis

Telomerase, a ribonuclearprotein complex, functions not only in cancer development but also in apoptosis, and senescence. As a catalytic subunit of telomerase, telomerase reverse transcriptase (TERT) has been confirmed to regulate telomerase activity in a rate-limiting manner. Although a lot of work has been done, the dynamic state of TERT protein and the relationship with telomerase have not been delineated systematically in cancer development. The purpose of this study was to do such an exploration. To investigate the role of TERT in the in vivo carcinogenesis, we performed immunofluorescence and Western blot analysis, respectively, to detect the alteration of TERT status as well as telomeric repeat amplification protocol (TRAP) assay to detect telomerase activity in diethyl nitrosoamine (DENA) induced rat hepatocellular carcinoma (HCC). The course of cancer development was divided into three main stages, which were inflammation ( <12 weeks), hepatocirrhosis (15 weeks), and hepatocarcinoma (18-21 weeks). In normal liver and its early inflammatory stage, concomitant with a weak positive TERT signal, which was detected exclusively in the cytoplasm, telomerase activity was very low at this stage. However, in late hepatocirrhosis and particularly cancer stage, high levels of TERT expression (P = 0.044 and P = 0.001, respectively) and telomerase activity (P = 0.02 and P = 0.01, respectively) were observed following TERT nuclear translocation. Our data suggest that TERT protein might regulate telomerase activity. TERT translocation from cytoplasm to the nucleus might be a turning point in cancer development. Therefore, TERT translocation might be more useful than TERT expression level and telomerase activity in predicting the progression of HCC.

Evaluation of centrosome abnormalities and p53 inactivation in chemical induced hepatocellular carcinogenesis

Abnormal centrosome frequently found in human cancer is a major cause of mitotic defects and chromosome instability in cancer cells. Centrosome duplication is controlled in a cell cycle-specific manner, whereas cancer cells with dysregulation of centrosome duplication can survive and reenter the cell cycle through defective cell cycle checkpoint systems. Although numerous studies showed that centrosome amplification can be readily induced by loss or mutational inactivation of p53, however, the role of centrosomally localized p53 in the regulation of centrosome duplication had been enigma. To investigate the role of centrosome and p53 in the in vivo carcinogenesis, we performed immunofluorescence and Western blot analysis, respectively, to detect the alteration of centrosome and p53 status as well as immunohistochemical assay to detect cell proliferation in diethyl nitrosoamine (DENA) induced rat hepatocellular carcinoma (HCC). The frequencies of the centrosome abnormalities in HCC lesions were significantly higher than that of in their preneoplasitc counterparts as well as cell proliferation expression profile. Intriguingly, there was no correlation between centrosome abnormalities and cell proliferation. As for p53, the level of p53 increased in inflammation lesion, but decreased in hepatocirrhosis lesion, even undetectable in HCC lesion. These findings may imply that in inflammatory lesions aberration centrosome occurred irrespective of p53 background. However, the significantly increased percentage of cells with abnormal centrosome in hepatocirrhosis, particularly in HCC lesion concomitant with p53 inactivation and increased cell proliferation rate might synergistically contribute to carcinogenesis. Taken together, centrosome abnormalities were an early event prior to p53 inactivation in the time course of carcinogenesis, suggesting that p53 inactivation may not be the cause of centrosome aberration and centrosome may be a susceptible organelle responding to cellular insults.

KEYWORDS

centrosome, p53, hepatocellular carcinoma, cell proliferation.

The pathologic features of neurocutaneous melanosis in a cynomolgus macaque

Neurocutaneous melanosis (NCM) is a rare phakomatosis characterized by proliferation of melanin-producing cells in both the skin and the brain. In this study, we describe the clinical and pathologic features of NCM in a 4.5-year-old female cynomolgus macaque. Histopathologically, skin lesions showed foci of nests and cords of pigmented cells in the dermis similar to blue nevi in humans. In the brain, focal pigmented cell infiltration was observed in the connective tissue under the leptomeninges and in the brain parenchyma. The pigmented cell was moderately reactive with a pan-melanoma antibody (melanoma(pan)) in the skin. In the brain, the pigmented cell was moderately to strongly positive for melanoma(pan) in subleptomeningeal areas and in the cerebral cortex. Melanosomes were observed in pigmented cells in the brain by electron microscopic examination. Based on the histologic, immunohistochemical, and electron microscopic results, the diagnosis of NCM was made. This case is possibly the first report of the condition in animals.

Murine bone marrow mesenchymal stem cells cause mature dendritic cells to promote T-cell tolerance

Bone mesenchymal stem cells (BMSC) are attractive not only in regenerative medicine, but also for the treatment of autoimmune diseases and graft-versus-host disease. BMSC also play a role in enabling alloantigen tolerance. An in-depth mechanistic understanding of this phenomenon of tolerance could lead to novel cell-based therapies for autoimmune disease. We demonstrate here that co-culture of mature dendritic cells (DC) with BMSC in a transwell system (BMSC-DC) downregulated expression of the maturation marker, CD83 and CD80/86 co-stimulatory molecules on DC, while increasing their endocytic activity. This resulted in defective antigen presentation and co-stimulatory capacity of mature DC. Functionally, BMSC-DC have impaired T-cell stimulatory activity in a mixed lymphocyte reaction and orchestrate a shift from predominantly pro-inflammatory T-helper (Th)-1 to anti-inflammatory Th2 cells. While the expression of MHC II, CD80 and CD86 were upregulated on BMSC co-cultured with DC, these BMSC lacked the ability to stimulate T-cell proliferation. Taken together, these data suggest that the interaction between BMSC and DC modulates the immunoregulatory function of these cells in a coordinated manner, effectively skewing the immune response towards T-cell tolerance.

Vacuum electron acceleration and bunch compression by a flat-top laser beam

The field intensity distribution and phase velocity characteristics of a flat-top laser beam are analyzed and discussed. The dynamics of electron acceleration in this kind of beam are investigated using three-dimensional test particle simulations. Compared with the standard (i.e., TEM(00) mode) Gaussian beam, a flat-top laser beam has a stronger longitudinal electric field and a larger diffraction angle. These characteristics make it easier for electrons to be trapped and accelerated by the beam. With a flat-top shape, the laser beam is also applicable to the acceleration of low energy electron and bunch compression.

Effect of FPS1 deletion on the fermentation properties of Saccharomyces cerevisiae

AIMS

To investigate the effect of FPS1 deletion on the fermentation properties of Saccharomyces cerevisiae and to evaluate whether FPS1 deletion would result in higher ethanol yield.

METHODS AND RESULTS

FPS1 of S. cerevisiae was knocked out using the one-step gene replacement method. The fermentation properties of the fps1Delta mutant under microaerobic conditions were investigated and compared with that of the wild type. Consumption of glucose, yield of ethanol, yield of glycerol, acetic acid and pyruvic acid were monitored. Compared with the wild type, the ethanol yield of the fps1Delta mutant was improved by 10 +/- 2% and glycerol yield decreased by 18.8 +/- 2%. Meanwhile, acetic acid yield decreased by 5.4 +/- 1%, and pyruvic acid yield decreased by 58.6 +/- 1%.

CONCLUSIONS

FPS1 deletion of S. cerevisiae resulted in reduced glycerol yield and higher ethanol yield.

SIGNIFICANCE AND IMPACT OF THE STUDY

The cost of carbon source in ethanol fermentation is an important factor in determining ethanol production. Approximately 5% carbon source is converted into glycerol in ethanol fermentation. Eliminating formation of glycerol through FPS1 deletion can be used to increase ethanol yield of S. cerevisiae without increasing the overall cost of carbon source.

Studies on a kinetic model for butyric acid bioproduction by Clostridium butyricum

AIMS

This paper discusses the establishment of a kinetic model for cell growth, butyric acid production and substrate consumption of Clostridium butyricum ZJUCB in batch cultivation.

METHODS AND RESULTS

Mathematic simulations were proposed by the logistic equation for the cell growth, the Luedeking-Piret equation for butyric acid production and the Luedeking-Piret-like equation for glucose consumption.

CONCLUSION

We compared the performance of our model against that obtained by the empirically experimental design. The experiment-validated model was found suitable for studying butyric acid fermentation kinetics in a complex dynamic behaviour of C. butyricum, especially for its singular growth phenomenon.

SIGNIFICANCE AND IMPACT OF THE STUDY

The model parameters are estimated from the data fitting and evaluated for simulation of the time courses of the concentrations of cell biomass, butyric acid and glucose and the model appears to fit the experimental data well. The results may be useful for butyric acid production by microbial fermentation.

7beta-hydroxycholesterol reduces the extent of reactive gliosis caused by iron deposition in the hippocampus but does not attenuate the iron-induced seizures in rats

7beta-Hydroxycholesterol has been previously demonstrated to inhibit astrocytosis in injured cortex or spinal cord of rats. In this study, we explored the inhibitory effects of the liposome containing 7beta-hydroxycholesterol on the reactive astrocytosis caused by the injection of iron into the hippocampus of rats and furthermore evaluated the involvement of reactive astrocytosis in iron-induced epilepsy. Injection of ferric chloride solution unilaterally into the hippocampus of rats induced spontaneous spiking activity ipsilaterally then developed into bilateral hippocampi and generalized convulsive seizures within the first week post-operation, and spontaneous epileptiform activity and generalized seizures lasted as long as 2 weeks post-operation, whereas none of the rats injected with sodium chloride solution unilaterally into the hippocampus developed generalized seizures. With immunohistochemistry and Western blot analyses, apparent reactive astrocytosis in bilateral hippocampi was detected using antibody against glial fibrillary acidic protein 14 days after the injection of ferric chloride solution, but no significant differences were found in the amount of synaptophysin protein, a presynaptic vesicle protein, as compared with the rats injected with sodium chloride solution. Infusion of liposome suspension containing 7beta-hydroxycholesterol into the same site immediately after the injection of ferric chloride solution reduced the extent of the reactive astrocytosis by 50%-55% of the amount of glial fibrillary acidic protein in the hippocampi of both hemispheres, and non-significantly elevated the amount of synaptophysin protein in both sides of hippocampus. However, these effects did not significantly modify the seizure latency and the incidence of generalized seizures in the rats. These findings demonstrate the effects of 7beta-hydroxycholesterol on the inhibition of reactive astrocytosis caused by iron deposition in the hippocampus of rats, and suggest that the reactive astrocytosis may not play a causal role in the development of iron-induced seizures.

Molecular determinants of P2Y2 nucleotide receptor function: implications for proliferative and inflammatory pathways in astrocytes

In the mammalian nervous system, P2 nucleotide receptors mediate neurotransmission, release of proinflammatory cytokines, and reactive astrogliosis. Extracellular nucleotides activate multiple P2 receptors in neurons and glial cells, including G protein-coupled P2Y receptors and P2X receptors, which are ligand-gated ion channels. In glial cells, the P2Y2 receptor subtype, distinguished by its ability to be equipotently activated by ATP and UTP, is coupled to pro-inflammatory signaling pathways. In situ hybridization studies with rodent brain slices indicate that P2Y2 receptors are expressed primarily in the hippocampus and cerebellum. Astrocytes express several P2 receptor subtypes, including P2Y2 receptors whose activation stimulates cell proliferation and migration. P2Y2 receptors, via an RGD (Arg-Gly-Asp) motif in their first extracellular loop, bind to alphavbeta3/beta5 integrins, whereupon P2Y2 receptor activation stimulates integrin signaling pathways that regulate cytoskeletal reorganization and cell motility. The C-terminus of the P2Y2 receptor contains two Src-homology-3 (SH3)-binding domains that upon receptor activation, promote association with Src and transactivation of growth factor receptors. Together, our results indicate that P2Y2 receptors complex with both integrins and growth factor receptors to activate multiple signaling pathways. Thus, P2Y2 receptors present novel targets to control reactive astrogliosis in neurodegenerative diseases.

Recombination of photodissociated iodine: A time-resolved x-ray-diffraction study

A time-resolved x-ray-diffraction experiment is presented that aims to study the recombination of laser-dissociated iodine molecules dissolved in CCl4. This process is monitored over an extended time interval from pico- to microseconds. The variations of atom-atom distances are probed with a milliangstrom resolution. A recent theory of time-resolved x-ray diffraction is used to analyze the experimental data; it employs the correlation function approach of statistical mechanics. The most striking outcome of this study is the experimental determination of time-dependent I-I atom-atom distribution functions. The structure of the CCl4 solvent changes simultaneously; the solvent thus appears as a reaction partner rather than an inert medium hosting it. Thermal expansion of the system is nonuniform in time, an effect due to the presence of the acoustic horizon. One concludes that a time-resolved x-ray diffraction permits real-time visualization of solvent and solute motions during a chemical reaction.