Rapid Detection of COVID-19 Using MALDI-TOF-Based Serum Peptidome Profiling.

The outbreak of coronavirus disease 2019 (COVID-19) caused by SARS CoV-2 is ongoing and a serious threat to global public health. It is essential to detect the disease quickly and immediately to isolate the infected individuals. Nevertheless, the current widely used PCR and immunoassay-based methods suffer from false negative results and delays in diagnosis. Herein, a high-throughput serum peptidome profiling method based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is developed for efficient detection of COVID-19. We analyzed the serum samples from 146 COVID-19 patients and 152 control cases (including 73 non-COVID-19 patients with similar clinical symptoms, 33 tuberculosis patients, and 46 healthy individuals). After MS data processing and feature selection, eight machine learning methods were used to build classification models. A logistic regression machine learning model with 25 feature peaks achieved the highest accuracy (99%), with sensitivity of 98% and specificity of 100%, for the detection of COVID-19. This result demonstrated a great potential of the method for screening, routine surveillance, and diagnosis of COVID-19 in large populations, which is an important part of the pandemic control.

The efficacy assessment of convalescent plasma therapy for COVID-19 patients: a multi-center case series.

Convalescent plasma (CP) transfusion has been indicated as a promising therapy in the treatment for other emerging viral infections. However, the quality control of CP and individual variation in patients in different studies make it rather difficult to evaluate the efficacy and risk of CP therapy for coronavirus disease 2019 (COVID-19). We aimed to explore the potential efficacy of CP therapy, and to assess the possible factors associated with its efficacy. We enrolled eight critical or severe COVID-19 patients from four centers. Each patient was transfused with 200-400 mL of CP from seven recovered donors. The primary indicators for clinical efficacy assessment were the changes of clinical symptoms, laboratory parameters, and radiological image after CP transfusion. CP donors had a wide range of antibody levels measured by serology tests which were to some degree correlated with the neutralizing antibody (NAb) level. No adverse events were observed during and after CP transfusion. Following CP transfusion, six out of eight patients showed improved oxygen support status; chest CT indicated varying degrees of absorption of pulmonary lesions in six patients within 8 days; the viral load was decreased to a negative level in five patients who had the previous viremia; other laboratory parameters also tended to improve, including increased lymphocyte counts, decreased C-reactive protein, procalcitonin, and indicators for liver function. The clinical efficacy might be associated with CP transfusion time, transfused dose, and the NAb levels of CP. This study indicated that CP might be a potential therapy for severe patients with COVID-19.

Antibody responses to SARS-CoV-2 in patients with COVID-19.

We report acute antibody responses to SARS-CoV-2 in 285 patients with COVID-19. Within 19 days after symptom onset, 100% of patients tested positive for antiviral immunoglobulin-G (IgG). Seroconversion for IgG and IgM occurred simultaneously or sequentially. Both IgG and IgM titers plateaued within 6 days after seroconversion. Serological testing may be helpful for the diagnosis of suspected patients with negative RT-PCR results and for the identification of asymptomatic infections.

Thrombolysis with alteplase 3-4.5 hours after acute ischaemic stroke: the first multicentre, phase III trial in China.

BACKGROUND AND PURPOSE: Data on the efficacy and safety of alteplase for acute ischaemic stroke (AIS) administered 3-4.5 hours after the onset of stroke symptoms in Chinese patients is limited. We sought to determine whether AIS patients would benefit from thrombolysis with alteplase between 3 and 4.5 hours after the onset of stroke symptoms in a prospective, multicentre, single-arm trial in China. MATERIALS AND METHODS: Eligible AIS patients were given 0.9 mg/kg alteplase intravenously. The primary efficacy endpoint was a favourable outcome at 3 months, defined as a score of 0 or 1 on the modified Rankin Scale. Thresholds for the primary efficacy endpoint were determined to be 40% based on the literature review. The primary safety endpoint was symptomatic intracranial haemorrhage (sICH) according to the European Cooperative Acute Stroke Study III (ECASS III) trial definition. Post hoc analysis between this study and the ECASS III trial were compared using the propensity score matching (PSM) method. RESULTS: A total of 120 eligible AIS patients from 11 sites in China received thrombolysis therapy in this study. The median time from onset of symptoms to needle was 3 hours 54 min. The percentage of patients with a favourable outcome was 63.3% (95% CI 54.4 to 71.4), significantly higher than the predefined threshold (p<0.0001). Three patients (2.5%, 95% CI 0.5 to 7.1) had sICH, including two fatal sICH. Six patients died within 3 months after treatment. The post hoc PSM analysis showed a numerically higher rate of the primary efficacy endpoint in this study (63.3%) than the matched placebo arm (56.7%) in the ECASS III trial. CONCLUSIONS: Intravenous alteplase with a standard dose administered between 3 and 4.5 hours after onset of symptoms is effective and safe for Chinese AIS patients. TRIAL REGISTRATION NUMBER: NCT02930837.

[A retrospective study on risk factors associated with postoperative delirium in elderly patients with spinal operation].

OBJECTIVE: To investigate the incidence and risk factors of delirium after spinal surgery in elderly patients. METHODS: A retrospective analysis was performed on 436 patients with spinal surgery from January 2016 to November 2018. According to delirium occurrancy after the operation, 436 cases were divided into two groups:delirium group and non-delirium group. Body mass index(BMI), history of diabetes, history of coronary heart disease, history of chronic obstructive pulmonary disease (COPD), preoperative white blood cell count, preoperative erythrocyte volume, preoperative hemoglobin level, operation mode, operation time, anesthesia time, American Association of Anesthesiologists(ANA)(ASA) score, cardiac function grading(NYHA), intraoperative blood loss, intraoperative blood transfusion, intraoperative fentanyl, propofol and Dizocine dosage, postoperative white blood cell count, postoperative erythrocyte volume, postoperative hemoglobin level, postoperative electrolytes (sodium, potassium) and univariate logistic regression analysis were used to analyze the risk factors. The independent risk factors were further investigated by multivariate Logistic regression analysis. RESULTS: Among 436 cases, 112 elderly patients had postoperative delirium, the incidence of delirium was about 25.68%. The age, preoperative leukocyte count, erythrocyte specific volume, postoperative hemoglobin level in delirium group and non-delirium group were measured. There were significant differences in the postoperative sodium concentration, anesthesia time, ASA score, cardiac function grading, blood loss during operation, postoperative use of Dizocine, history of diabetes, history of coronary heart disease and history of COPD (P<0.05). Multivariate logistic regression analysis showed that the age, ASA score, postoperative Dizocine volume, and COPD history were independent risk factors for the occurrence of delirium after spinal surgery in elderly patients. CONCLUSIONS: The elderly patients over 72 years old, the ASA score>2, the use of Dizocine analgesic and the patients with COPD are the independent risk factors of postoperative delirium.

Alternating Tetrafluorobenzene and Thiophene Units by Direct Arylation for Organic Electronics.

Direct arylation represents an attractive alternative to the conventional cross-coupling methods because of its step-economic and eco-friendly advantages. A set of simple D-A oligomeric molecules (F-3, F-5, and F-7) by integrating thiophene (T) and tetrafluorobenzene (F4B) as alternating units through a direct arylation strategy is presented to obtain high-performance charge-transporting materials. Single-crystal analysis revealed their herringbone packing arrangements driven by intensive C-H⋅⋅⋅π interactions. An excellent hole-transporting efficiency based on single-crystalline micro-plates/ribbons was witnessed, and larger π-conjugation and D-A constitution gave higher mobilities. Consequently, an average mobility of 1.31 cm2 V-1 s-1 and a maximum mobility of 2.44 cm2 V-1 s-1 for F-7 were achieved, providing an effective way to obtain high-performance materials by designing simple D-A oligomeric systems.

Hexacene Diimides.

Acene imides are expected to possess smaller band gaps than homologous acenes while maintaining good solubility and stability. However, the design and synthesis of large acene imides are still a big challenge. Herein, we report a one-pot synthesis of hexacene diimides (HDI) by double aromatic annulation between zirconabenzocyclopentene and tetrabrominated naphthalene diimides. HDIs with branched alkyl chains exhibit very good solubility, stability, and much smaller band gaps than hexacene. Organic field-effect transistors (OFETs) based on HDI microribbons exhibit excellent ambipolar transport behavior with the highest electron mobility of 2.17 cm2 V-1 s-1 and hole mobility of 0.30 cm2 V-1 s-1 under ambient conditions.

Comorbidity Burden of Dementia: A Hospital-Based Retrospective Study from 2003 to 2012 in Seven Cities in China.

Dementia is increasing dramatically and imposes a huge burden on society. To date, there is a lack of data on the health status of patients with dementia in China. In an attempt to investigate the comorbidity burden of dementia patients in China at the national level, we enrolled 2,938 patients with Alzheimer's disease (AD), vascular dementia (VaD), or other types of dementia, who were admitted to tertiary hospitals in seven regions of China from January 2003 to December 2012. The Charlson Comorbidity Index (CCI) was used to evaluate the comorbidity burden of the patients with dementia. Among these patients, 53.4% had AD, 26.3% had VaD, and 20.3% had other types of dementia. The CCI was 3.0 ± 1.9 for all patients, 3.4 ± 1.8 for those with VaD, and 3.0 ± 2.1 for those with AD. The CCI increased with age in all patients, and the length of hospital stay and daily expenses rose with age and CCI. Males had a higher CCI and a longer stay than females. Moreover, patients admitted in the last 5 years of the study had a higher CCI than those admitted in the first 5 years. We found that the comorbidity burden of patients with dementia is heavy. These findings provide a better understanding of the overall health status of dementia patients, and help to increase the awareness of clinicians and policy-makers to improve medical care for patients.

α-Linolenic Acid Inhibits Receptor Activator of NF-κB Ligand Induced (RANKL-Induced) Osteoclastogenesis and Prevents Inflammatory Bone Loss via Downregulation of Nuclear Factor-KappaB-Inducible Nitric Oxide Synthases (NF-κB-iNOS) Signaling Pathways.

BACKGROUND Inflammation is a major cellular strain causing increased risk of osteo-degenerative diseases. Omega-3 fatty acids have been great source in suppressing inflammation. We investigated the effect of α-linolenic acid (ALA) on RANKL-stimulated osteoclast differentiation, LPS-induced and ovariectomized bone loss in mice models. MATERIAL AND METHODS The bone marrow macrophages (BMMs) were isolated from femurs of ICR mice, stimulated with RANKL, and treated with ALA (100, 200, 300 µM). Major analytical methods include histological analysis, osteoclasts viability assay, serum cytokines and chemokines ELISA, and gene expression by qPCR. RESULTS ALA intervention inhibited RANKL-induced osteoclasts proliferation and differentiation. ALA inhibited bone resorption activity as measured by materialization of F-actin ring structures as well. ALA suppressed the RANKL-induced osteoclast markers c-Fos, c-Jun and NFATc1 together with transcription factor proteins TRAP, OSCAR, cathepsin K and ß3-integrin. ALA also suppressed the RANKL-stimulated phosphorylation of JNK, ERK, and AKT as well as NF-κB and BCL-2 proteins. ALA intervention (100 and 300 mg/kg) to LPS-challenged mice showed annulled morphometric changes induced by LPS by suppressing the levels of proinflammatory cytokines and chemokines. ALA (100 and 300 mg/kg) intervention to estrogen-deficiency induced bone loss mice (ovariectomized) showed reductions in TRAP+ osteoclasts count, CTX-I expression, levels of IL-1ß, IL-2, IL-6, IL10, TNF-α and MCP-1 and iNOS and COX-2. CONCLUSIONS ALA suppresses RANKL-induced osteoclast differentiation and prevents inflammatory bone loss via downregulation of NF-κB-iNOS-COX-2 signaling. ALA is suggested to be a preventive herbal medicine against inflammatory bone disorders.

Comorbidity burden of patients with Parkinson's disease and Parkinsonism between 2003 and 2012: A multicentre, nationwide, retrospective study in China.

Parkinson's disease (PD) and Parkinsonism are common neurodegenerative disorders with continuously increasing prevalence, causing high global burdens. However, data concerning the comorbidity burden of patients with PD or Parkinsonism in China are lacking. To investigate the health condition and comorbidity burden, a total of 3367 PD and 823 Parkinsonism patients were included from seven tertiary hospitals in seven cities across China from 2003 to 2012. Their comorbidity burden was collected and quantified by the Elixhauser Comorbidity Index (ECI) and Charlson Comorbidity Index (CCI). The comorbidity spectra differed between PD and Parkinsonism patients. Compared with PD patients, Parkinsonism patients were older (69.8 ± 11.5 vs. 67.9 ± 11.4, P < 0.001); had a higher comorbidity burden, including ECI (1.1 ± 1.2 vs. 1.0 ± 1.2, P < 0.001) and CCI (1.3 ± 1.6 vs. 1.1 ± 1.5, P < 0.001); and had higher hospitalization expenses. The ECI (1.1 ± 1.3 vs. 0.9 ± 1.1, P < 0.001) and CCI (1.3 ± 1.6 vs. 0.9 ± 1.2, P < 0.001) were higher in males than in females. The average length of stay and daily hospitalization expenses increased with age, as did ECI and CCI. This is the first study to report the disease burden of Chinese PD and Parkinsonism patients. It provides useful information to better understand their health status, and to raise the awareness of clinicians for providing better health care.

Efficacy of Vitamin B Supplementation on Cognition in Elderly Patients With Cognitive-Related Diseases.

Increase in serum homocysteine is shown to be a potential risk factor for cognitive impairment. Evidence suggests that vitamin B supplementation may reduce cognitive decline by lowering the homocysteine levels. The current meta-analysis evaluated the efficacy of folic acid along with vitamin B12 and/or B6 in lowering homocysteine, thereby attenuating cognitive decline in elderly patients with Alzheimer disease or dementia. Randomized controlled trials (RCTs) comparing the efficacy of folate and B vitamin supplementation in patients with cognitive decline secondary to Alzheimer disease or dementia were identified using the keywords, "homocysteine, hyper-homocysteinemia, B vitamin, vitamin B6, B12, folic acid, cognitive, Alzheimer's disease, and dementia." The outcome measures analyzed were the Mini-Mental State Examination (MMSE) score and serum homocysteine. Of the 77 studies identified, 4 RCTs were included in the current meta-analysis. The baseline characteristics, age, and gender distribution of patients among the 2 groups (supplement vs placebo) were comparable. The results reveal that the intervention group achieved significantly greater reduction in homocysteine levels than the control (pooled difference in means = -3.625, 95% confidence interval [CI] = -5.642 to -1.608, P < .001). However, no significant difference in MMSE (pooled difference in means = 0.027, 95% CI = -0.518 to 0.573, P = 0.921) was observed between the groups. Taken together, vitamin B supplementation was effective in reducing serum homocysteine levels. However, it did not translate into cognitive improvement, indicating that the existing data on vitamin B-induced improvement in cognition by lowering homocysteine levels are conflicting.

Angioplasty and stenting for patients with symptomatic intracranial atherosclerosis: study protocol of a randomised controlled trial.

INTRODUCTION: Whether adding percutaneous transluminal angioplasty and stenting (PTAS) to background medical treatment is effective for decreasing the incidence of stroke or death in patients with symptomatic intracranial atherosclerosis (ICAS) is still controversial. We perform a randomised controlled trial to examine the effectiveness and safety of an improved PTAS procedure for patients with ICAS. METHODS AND ANALYSIS: A randomised controlled trial will be conducted in three hospitals in China. Eligible patients with ICAS will be randomly assigned to receive medication treatment (MT) plus PTAS or MT alone. The MT will be initiated immediately after randomisation, while the PTAS will be performed when patients report relief of alarm symptoms defined as sudden weakness or numbness. All patients will be followed up at 30 days, 3 and 12 months after randomisation. The primary end point will be the incidence of stroke or death at 30 days after randomisation. Secondary outcomes will be the incidence of ischaemic stroke in the territory of stenosis arteries, the incidence of in-stent restenosis, the Chinese version of the modified Rankin Scale and the Chinese version of the Stroke-Specific Quality of Life (CSQoL). ETHICS AND DISSEMINATION: The study protocol is approved by institutional review boards in participating hospitals (reference number FZ20160003, 180PLA20160101 and 476PLA2016007). The results of this study will be disseminated to patients, physicians and policymakers through publication in a peer-reviewed journal or presentations in conferences. It is anticipated that the results of this study will improve the quality of the current PTAS procedure and guide clinical decision-making for patients with ICAS. TRIAL REGISTRATION NUMBER: NCT02689037.

Polycyclic aromatic hydrocarbons with orthogonal tetraimides as n-type semiconductors.

Two new polycyclic aromatic hydrocarbons with orthogonal imide groups have been synthesized and characterized. These semiconductors have strong electron affinities with an electron mobility of up to 1.75 cm2 V-1 s-1 in solution-processed single-crystalline microfibers.

ISART: A Generic Framework for Searching Books with Social Information.

Effective book search has been discussed for decades and is still future-proof in areas as diverse as computer science, informatics, e-commerce and even culture and arts. A variety of social information contents (e.g, ratings, tags and reviews) emerge with the huge number of books on the Web, but how they are utilized for searching and finding books is seldom investigated. Here we develop an Integrated Search And Recommendation Technology (IsArt), which breaks new ground by providing a generic framework for searching books with rich social information. IsArt comprises a search engine to rank books with book contents and professional metadata, a Generalized Content-based Filtering model to thereafter rerank books with user-generated social contents, and a learning-to-rank technique to finally combine a wide range of diverse reranking results. Experiments show that this technology permits embedding social information to promote book search effectiveness, and IsArt, by making use of it, has the best performance on CLEF/INEX Social Book Search Evaluation datasets of all 4 years (from 2011 to 2014), compared with some other state-of-the-art methods.

Rg1 exhibits neuroprotective effects by inhibiting the endoplasmic reticulum stress-mediated c-Jun N-terminal protein kinase apoptotic pathway in a rat model of Alzheimer's disease.

The neuroprotective agents currently used to treat Alzheimer's disease (AD) often only target one aspect of the disease process. Therefore, identifying effective drug targets associated with the pathogenesis of AD is critical for the production of novel AD therapeutic strategies. The present study aimed to investigate the underlying mechanisms of the neuroprotective effects of Rg1 on a rat model of AD. A double transgenic ß­amyloid (Aß) precursor protein/PS1 rat model was established, which co­expressed mutations associated with AD. Aß plaques and neurofibrillary tangles (NFTs) were detected by immunohistochemistry. The detection of the protein expression levels of caspase­3 and terminal deoxynucleotidyl­transferase­mediated dUTP nick end labeling (TUNEL) staining were used to determine the level of apoptosis in the brain tissue. The expression levels of the endoplasmic reticulum (ER) stress biomarker, glucose­regulated protein 78 (Grp78), and the mitochondrial apoptosis biomarkers, B­cell lymphoma 2 (Bcl­2) and Bcl­2­associated X protein (Bax), were analyzed by western blotting. Furthermore, the expression of the proteins associated with the ER stress unfolded protein response (UPR) was determined, in order to examine the levels of ER stress. The mRNA expression of downstream genes of UPR were also detected by reverse transcription­polymerase chain reaction. The protein expression levels of the apoptosis­associated phosphorylated­c­Jun N­terminal protein kinase (p­JNK), caspase­12 and cAMP response element­binding transcription factor homologous protein were determined by western blotting. The results of the present study indicated that the accumulation of NFTs and Aß plaques was significantly decreased in the Rg1­treated AD rats, compared with untreated AD rats. The expression of caspase­3 and the number of TUNEL­positive cells were also significantly decreased in the Rg1­treated rats, as compared with the AD rats. Furthermore, treatment with Rg1 significantly reduced the expression of Grp78, and triggered inositol­requiring enzyme­1 (IRE­1) and phosphorylated protein kinase RNA­like ER kinase­associated ER stress. The IRE­1 UPR pathway downstream gene, tumor necrosis factor receptor­associated factor 2, was significantly decreased in rats treated with Rg1, compared with untreated AD rats. Furthermore, the activation of p­JNK was also inhibited when AD rats were treated with Rg1. In conclusion, Rg1 was shown to function as an important factor that inhibits the accumulation of NFTs and Aß via inhibition of the ER stress­mediated pathway. Blocking of this pathway was triggered by the IRE­1 and TRAF2 pathway, as a result of inhibition of the expression of p­JNK.

Efficacy, safety, and tolerability of telcagepant in the treatment of acute migraine: a meta-analysis.

Although triptans are widely used for treating acute migraine, they are contraindicated or not effective in a large proportion of patients. Hence, alternative treatments are needed. Calcitonin gene-related peptide receptor antagonists, such as telcagepant, have been under investigation as a treatment for acute migraine. A meta-analysis of the efficacy of telcagepant vs. placebo and triptans (zolmitriptan or rizatriptan) was performed. Randomized controlled trials were indentified from databases using the following search terms: migraine; calcitonin gene-related peptide; calcitonin gene-related peptide receptor antagonists; efficacy; safety, and telcagepant. The primary outcome measure was pain freedom 2 hours after first treatment. The secondary outcome measure was pain relief 2 hours after first treatment. Eight trials were included in the meta-analysis (telcagepant = 4011 participants). The difference in pain freedom at 2 hours significantly favored telcagepant over placebo (odds ratio = 2.70, 95% confidence interval = 2.27-3.21, P < 0.001) and triptans over telcagepant (odds ratio = 0.68, 95% confidence interval = 0.56-0.83, P < 0.001). The difference in pain relief at 2 hours significantly favored telcagepant over placebo (odds ratio = 2.48, 95% confidence interval = 2.18-2.81, P < 0.001). The difference in pain relief at 2 hours did not significantly favor telcagepant over triptans or vice versa (odds ratio = 0.76, 95% confidence interval = 0.57-1.01, P = 0.061). These findings indicate that telcagepant can be effective for treating acute migraine. Calcitonin gene-related peptide receptor antagonists represent a potentially important alternative means of treating acute migraine.

Polymorphism of the RAGE affects the serum inflammatory levels and risk of ischemic stroke in a Chinese population.

BACKGROUND: Increasing evidence shows that inflammation plays an important role in the occurrence and progression of acute ischemic stroke. The receptor for advanced glycation end products (RAGE) has been documented to involve in the pathogenic mechanisms of a variety of neurological diseases, including ischemic stroke (IS). However, the impact of RAGE gene polymorphisms on the susceptibility to IS has not been reported. We thus explored the association between RAGE gene polymorphisms and the susceptibility to IS. METHOD: A total of 384 patients with IS and 425 healthy controls were enrolled in this study. Three genetic polymorphisms of RAGE gene (82G/S, -429T/C and -374T/A) were determined. The serum levels of soluble RAGE (sRAGE), intetleukin-6 (IL-6), high sensitivity-C reaction protein (hs-CRP) and plasminogen activator inhibitor-1 (PAI-1) were detected. RESULTS: Among the studied polymorphisms, only the polymorphism at 82G/S of RAGE gene was associated with the risk for ischemic stroke irrespective of the stroke subtypes. The 82S/S homozygote carriers had a significantly increased risk for ischemic stroke [adjusted odds ratio (OR): 2.297; p<0.001]. The haplotype analyses showed that the C-429S82T-374 and T-429S82A-374 had higher risk to develop IS (OR=1.864 and 1.931, respectively, all p<0.01), while the C-429G82T-374 showed a protective effect against IS susceptibility (OR=0.568, p=0.001). In addition, the 82S/S homozygote carriers had a higher inflammatory level compared with 82G/S and 82G/G genotypes, indicated by lower serum sRAGE level, higher serum IL-6, hs-CRP and PAI-1 levels. The polymorphisms at -374 and -429 loci did not influence the stroke risk and the above mentioned inflammation cytokines. CONCLUSION: Our results showed a close correlation between the 82G/S polymorphism and the susceptibility to IS, suggesting the 82G/S polymorphism may be used as a genetic marker for the prediction of stroke occurrence in high risk subjects.

Both CpG methylation and activation-induced deaminase are required for the fragility of the human bcl-2 major breakpoint region: implications for the timing of the breaks in the t(14;18) translocation.

The t(14;18) chromosomal translocation typically involves breakage at the bcl-2 major breakpoint region (MBR) to cause human follicular lymphoma. A theory to explain the striking propensity of the MBR breaks at three CpG clusters within the 175-bp MBR region invoked activation-induced deaminase (AID). In a test of that theory, we used here minichromosomal substrates in human pre-B cell lines. Consistent with the essential elements of the theory, we found that the MBR breakage process is indeed highly dependent on DNA methylation at the CpG sites and highly dependent on the AID enzyme to create lesions at peak locations within the MBR. Interestingly, breakage of the phosphodiester bonds at the AID-initiated MBR lesions is RAG dependent, but, unexpectedly, most are also dependent on Artemis. We found that Artemis is capable of nicking small heteroduplex structures and is even able to nick single-base mismatches. This raises the possibility that activated Artemis, derived from the unjoined D to J(H) DNA ends at the IgH locus on chromosome 14, nicks AID-generated TG mismatches at methyl CpG sites, and this would explain why the breaks at the chromosome 18 MBR occur within the same time window as those on chromosome 14.

Effect of basic fibroblast growth factor on hippocampal cholinergic neurons in a rodent model of ischaemic encephalopathy.

Ischaemic encephalopathy (IE) is a debilitating condition resulting from stroke that can lead to impaired learning and memory related to damage of cholinergic neurons in the hippocampus. The present study used an animal model of IE to test the hypothesis that treatment with basic fibroblast growth factor (bFGF) can reduce cognitive symptoms of IE by increasing the number of cholinergic neurons in the CA region of the hippocampus. The animal model of IE was created surgically by double ligation of the bilateral common carotid arteries. Three groups of Sprague-Dawley rats: sham, IE and IE with bFGF treatment group, were measured for changes in learning and memory using the Morris water maze test. Microscopic and immunohistochemical techniques were used to identify cells that bind bFGF and cholinergic neurons. IE rats treated with bFGF had better scores in the Morris water maze test than the untreated IE group, indicating improved learning and memory in the treated group. Microscopy showed that bFGF crossed the blood-brain barrier, was taken up by neurons in the hippocampus, and that the number of cholinergic neurons in the treated group was significantly increased. These results may provide an experimental basis for the treatment of IE by subcutaneous injection of bFGF.

Isolation of high quality RNA and construction of a suppression subtractive hybridization library from ramie (Boehmeria nivea L. Gaud.).

Isolation of high quality RNA from ramie (Boehmeria nivea L. Gaud.) is difficult due to its high levels of polyphenols, polysaccharides, pectin, fat, wax and other secondary metabolites. A modified procedure based on guanidinium isothiocyanate for RNA preparation of ramie was developed in this study. High concentrations (5%, v/v) of guanidinium isothiocyanate, PVP-4000, sodium citrate and sodium lauryl sarcosinate and beta-mercaptoethanol were used in the extraction buffer, together with a low pH sodium acetate (pH 4.0) added to improve the RNA quality. The average yield was about 400 microg RNAg(-1) fresh leaves. One SSH library which was induced by ramie anthracnose was constructed by utilizing the RNA extracted through the present method. These results showed that our protocol was applicable for RNA isolation from recalcitrant ramie tissues.