CCNA2 and NEK2 regulate glioblastoma progression by targeting the cell cycle

Glioblastoma (GBM) is characterized by significant heterogeneity, leading to poor survival outcomes for patients, despite the implementation of comprehensive treatment strategies. The roles of cyclin A2 (CCNA2) and NIMA related kinase 2 (NEK2) have been extensively studied in numerous cancers, but their specific functions in GBM remain to be elucidated. The present study aimed to investigate the potential molecular mechanisms of CCNA2 and NEK2 in GBM. CCNA2 and NEK2 expression and prognosis in glioma were evaluated by bioinformatics methods. In addition, the distribution of CCNA2 and NEK2 expression in GBM subsets was determined using pseudo-time analysis and tricycle position of single-cell sequencing. Gene Expression Omnibus and Kyoto Encyclopedia of Genes and Genome databases were employed and enrichment analyses were conducted to investigate potential signaling pathways in GBM subsets and a nomogram was established to predict 1-, 2- and 3-year overall survival probability in GBM. CCNA2 and NEK2 expression levels were further validated by western blot analysis and immunohistochemical staining in GBM samples. High expression of CCNA2 and NEK2 in glioma indicates poor clinical outcomes. Single-cell sequencing of GBM revealed that these genes were upregulated in a subset of positive neural progenitor cells (P-NPCs), which showed significant proliferation and progression properties and may activate G2M checkpoint pathways. A comprehensive nomogram predicts 1-, 2- and 3-year overall survival probability in GBM by considering P-NPCs, age, chemotherapy and radiotherapy scores. CCNA2 and NEK2 regulate glioblastoma progression by targeting the cell cycle, thus indicating the potential of novel therapy directed to CCNA2 and NEK2 in GBM.

Genome-wide association study of growth curve parameters reveals novel genomic regions and candidate genes associated with metatarsal bone traits in chickens

The growth and development of chicken bones have an enormous impact on the health and production performance of chickens. However, the development pattern and genetic regulation of the chicken skeleton are poorly understood. This study aimed to evaluate metatarsal bone growth and development patterns in chickens via non-linear models, and to identify the genetic determinants of metatarsal bone traits using a genome-wide association study (GWAS) based on growth curve parameters. Data on metatarsal length (MeL) and metatarsal circumference (MeC) were obtained from 471 F2 chickens (generated by crossing broiler sires, derived from a line selected for high abdominal fat, with Baier layer dams) at 4, 6, 8, 10, and 12 weeks of age. Four non-linear models (Gompertz, Logistic, von Bertalanffy, and Brody) were used to fit the MeL and MeC growth curves. Subsequently, the estimated growth curve parameters of the mature MeL or MeC (A), time-scale parameter (b), and maturity rate (K) from the non-linear models were utilized as substitutes for the original bone data in GWAS. The Logistic and Brody models displayed the best goodness-of-fit for MeL and MeC, respectively. Single-trait and multi-trait GWASs based on the growth curve parameters of the Logistic and Brody models revealed 4 618 significant single nucleotide polymorphisms (SNPs), annotated to 332 genes, associated with metatarsal bone traits. The majority of these significant SNPs were located on Gallus gallus chromosome (GGA) 1 (167.433-176.318 Mb), GGA2 (96.791-103.543 Mb), GGA4 (65.003-83.104 Mb) and GGA6 (64.685-95.285 Mb). Notably, we identified 12 novel GWAS loci associated with chicken metatarsal bone traits, encompassing 35 candidate genes. In summary, the combination of single-trait and multi-trait GWASs based on growth curve parameters uncovered numerous genomic regions and candidate genes associated with chicken bone traits. The findings benefit an in-depth understanding of the genetic architecture underlying metatarsal growth and development in chickens.

[Research progress on distribution characteristics and health risk assessment of bioaerosols in medical institutions]

Bioaerosols in healthcare facilities are closely related to the health of medical staff and patients. Inhalation of microbial aerosol particles can lead to both infectious and non-infectious diseases. However, a systematic summary of bioaerosol types, sources, impact factors and health risk analysis is lacking.This article condutcted a literature review to understand the distribution characteristics, sources, influencing factors and health risks of bioaerosols in healthcare facilities, both domestically and internationally. The goal is to increase awareness of the distribution characteristics of bioaerosols in healthcare facilities and health risk of bioaerosols in medical institutions. This article also provides a reference for prevention and control of bioaerosols.

CXCL5 promotes tumorigenesis and angiogenesis of glioblastoma via JAK-STAT/NF-κb signaling pathways

BACKGROUND

The tumor microenvironment contains chemokines that play a crucial role in various processes, such as tumorigenesis, inflammation, and therapy resistance, in different types of cancer. CXCL5 is a significant chemokine that has been shown to promote tumor proliferation, invasion, angiogenesis, and therapy resistance when overexpressed in various types of cancer. This research aims to investigate the impact of CXCL5 on the biological functions of glioblastoma (GBM).

METHODS

The TCGA GBM and GEO databases were utilized to perform transcriptome microarray analysis and oncogenic signaling pathway analysis of CXCL5 in GBM. Validation of CXCL5 expression was performed using RT-qPCR and Western Blot. The impact of CXCL5 on cell proliferation, tumorigenesis, and angiogenesis in GBM was assessed through various methods, including cell proliferation assay, cloning assay, intracranial xenograft tumor models, and tube formation assay. Clinical prognosis was evaluated in 59 samples of gliomas with varying degrees of malignancy (grades 2, 3, and 4) and the TCGA GBM database, based on CXCL5 expression levels. The activities of the JAK-STAT and NF-κB signaling pathways were detected using Western Blot.

RESULTS

The expression of CXCL5 was highly enriched in GBM. Moreover, the inhibition of CXCL5 showed a significant efficacy in suppressing cellular proliferation and angiogenesis, resulting in extended survival rates in xenograft mouse models in comparison to the control group. Notably, pretreatment with dapsone exhibited a reversal of the impact of CXCL5 on the formation of colonies and tubes in GBM cells. Elevated expression of CXCL5 was correlated with poor outcomes in GBM patients. Furthermore, the overexpression of CXCL5 has been associated with the activation of JAK-STAT and NF-κB signaling pathways.

CONCLUSIONS

CXCL5 plays an important role in tumorigenesis and angiogenesis, indicating the potential for novel therapies targeting CXCL5 in GBM.

Prognostic Significance of the Novel Nutrition-Inflammation Marker of Lymphocyte-C-Reactive Protein Ratio in Patients with Nasopharyngeal Carcinoma Receiving Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

Recent studies indicate that the novel lymphocyte-C-reactive protein ratio (LCR) is strongly associated with the survival of various tumors, but its prognostic value in nasopharyngeal carcinoma (NPC) is understudied. This study aimed to explore the relationship between the LCR and overall survival (OS) in NPC and to develop a predictive model.

MATERIALS/METHODS

A total of 841 NPC patients received concurrent chemoradiotherapy (CCRT) were retrospectively enrolled and randomly divided into training cohort (n = 589) and validation cohort (n = 252). Univariate and multivariate Cox analyses were performed to identify variables associated with OS and construct a predictive nomogram. The predictive accuracy of the nomogram was evaluated and independently validated.

RESULTS

The LCR score differentiated NPC patients into two groups with distinct prognoses (HR = 0.53; 95% CI: 0.32-0.89, P = 0.014). Multivariate analysis showed that age, T stage, N stage, EBV-DNA status, and LCR score were independently associated with OS and a predictive nomogram was developed. The nomogram had a good performance for the prediction of OS [C-index = 0.770 (95% CI: 0.675-0.864)] and outperformed the traditional staging system [C-index = 0.589 (95% CI: 0.385-0.792)]. The results were internally validated using an independent cohort.

CONCLUSION

The novel nutrition-inflammation marker of LCR could serve as a simplified, affordable, easy-to-obtain, non-invasive, and readily promotive prognostic marker for NPC patients received CCRT, and the LCR-based prognostic nomogram outperformed the conventional staging system in terms of predictive power.

circKIF4A promotes tumorogenesis of glioma by targeting miR-139-3p to activate Wnt5a signaling

Background

Glioma has the characteristics of high incidence and mortality, and is a common malignant tumor of the central nervous system. Circular RNAs (circRNAs) have been reported to play vital roles in progression of cancer including glioma, and circKIF4A is up-regulated in glioma tissues. However, its role and mechanisms in gliomas are unclear.

Methods

circKIF4A and miR-139-3p were determined by qRT-PCR. Transwell assay, wound-healing assay, cell colony formation and flow cytometry were performed to measure cell invasion, migration, proliferation and apoptosis. Western blotting was used to evaluate Wnt/β-catenin pathway-related protein. Luciferase reporter assays confirmed the relationship among circKIF4A, miR-139-3p and Wnt5a. Sphere formation was performed to measure the ability of glioma-initiating cells (GICs) spheroid formation. A nude mouse xenograft model was established and immunohistochemical staining was used to detect Ki-67 and Wnt5a levels.

Results

circKIF4A and Wnt5a were up-regulated and miR-139-3p was down-regulated in both glioma cells and tissues. circKIF4A promoted Wnt5a expression by sponging miR-139-3p. Knockdown of circKIF4A inhibited the colony formation ability, migration and invasion, and promoted the apoptosis of glioma cells by regulating miR-139-3p. Knockdown of circKIF4A inhibited Wnt/β-catenin signaling pathway and proliferation-related signal via miR-139-3p. Furthermore, knockdown of circKIF4A or overexpression of miR-139 suppressed the ability of sphere formation of GICs and inhibitd Wnt/β-catenin signaling pathway and proliferation-related signal in GICs. Additionally, depletion of circKIF4A decreased the expression level of Wnt5a and Ki-67, inhibited tumorigenesis in xenograft modes.

Conclusion

circKIF4A was overexpressed in glioma, and knockdown of circKIF4A suppressed glioma progression via miR-139-3p/Wnt5a axis. The results indicated that circKIF4A may be a potential target for clinical treatment of glioma.

PDZ-Binding Kinase-Dependent Transcriptional Regulation of CCNB2 Promotes Tumorigenesis and Radio-Resistance in Glioblastoma

Increasing evidence has indicated that PDZ binding kinase (PBK) promotes proliferation, invasion, and therapeutic resistance in a variety of cancer types. However, the physiological function and therapy-resistant role of PBK in GBM remain underexplored. In this study, PBK was identified as one of the most therapy-resistant genes with significantly elevated expression level in GBM. Moreover, the high expression level of PBK was essential for GBM tumorigenesis and radio-resistance both in vitro and in vivo. Clinically, aberrant activation of PBK was correlated with poor clinical prognosis. In addition, inhibition of PBK dramatically enhanced the efficacy of radiation therapy in GBM cells. Mechanically, PBK-dependent transcriptional regulation of CCNB2 was critical for tumorigenesis and radio-resistance in GBM cells. Collectively, PBK promotes tumorigenesis and radio-resistance in GBM and may serve as a novel therapeutic target for GBM treatment.

Retraction: Receptor tyrosine kinase AXL is correlated with poor prognosis and induces temozolomide resistance in glioblastoma

Retraction: Receptor tyrosine kinase AXL is correlated with poor prognosis and induces temozolomide resistance in glioblastoma, CNS Neuroscience & Therapeutics 2019, (https://doi.org/10.1111/cns.13227). The above article published online on 02 October 2019 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief Jun Chen, and John Wiley & Sons Ltd. The retraction has been agreed due to unreliable data and consequently its misleading results and conclusions.

Metformin inhibits metastatic breast cancer progression and improves chemosensitivity by inducing vessel normalization via PDGF-B downregulation

Background

Vascular maturity and functionality are closely associated with tumor progression and chemosensitivity. The antidiabetic agent metformin has shown its ability to inhibit tumor angiogenesis in metastatic breast cancer models. However, it remains unclear if or how metformin remodels the abnormal vasculature of metastatic breast cancer, while inhibiting angiogenesis.

Methods

Metastatic breast cancer models were constructed to compare microvessel density (MVD), vascular maturity and function, lung metastasis and chemosensitivity in metformin-treated or untreated mice. Protein array assay and transcriptome sequencing were performed for genetic screening. Lentiviral shRNA-PDGF-B transfection was used for observing the contribution of PDGF-B knockdown to metformin’s vascular effects.

Results

Metastatic breast cancers were characterized by an excessively angiogenic, immature and morphologically abnormal vasculature. Compared to control, metformin significantly reduced MVD, leakage and hypoxia, and increased vascular mural cells coverage and perfusion, namely, “vessel normalization”. Metformin at human blood concentrations had no direct effect on the migration and proliferation of cancer cells. Based on that, reduced lung metastasis of the primary tumor and improved chemosensitization by metformin were assumed to be mediated via metformin’s vascular effects. Further results of genetic screening and in vivo experiments showed that the downregulation of platelet-derived growth factor B (PDGF-B) greatly contributed to the metformin-induced vessel normalization.

Conclusions

These findings provide pre-clinical evidences for the vascular mechanism of metformin-induced metastasis inhibition and the chemosensitization of metastatic breast cancers.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1211-2) contains supplementary material, which is available to authorized users.

[BABA of da Vinci robot thyroid surgery in the standard treatment of thyroid cancer surgery]

Thyroid cancer is the most common malignant tumor in endocrine surgery. Surgery is the first choice for most patients with thyroid cancer. Da Vinci robot system as the auxiliary system is the most advanced endoscopic surgery, largely to fill the cavity mirror device cannot bend, complex operation and so on insufficiency, has now become an important way of surgical treatment of thyroid cancer, and its curative effect, high safety, but because of the economic cost is higher, is currently not widespread popularity.

Salvianolic acid B renders glioma cells more sensitive to radiation via Fis-1-mediated mitochondrial dysfunction

Glioma remains the leading cause of brain tumor-related death worldwide, and radiation is a standard adjuvant therapy with proven efficacy. Salvianolic acid B (SalB), a bioactive compound isolated from Radix Salviae, has been shown to exert anti-cancer effects in many cancer cell lines, including glioma. This study aimed to investigate whether SalB could affect response to radiation in human glioma cells. We found that SalB decreased cell viability of U87 cells in a-dose-dependent manner. A subthreshold dose of SalB at 0.5 μM, which had no effect on cell viability and apoptosis, significantly increased radiation sensitivity of U87 cells in a dose- and time-dependent manner, but had no effect on sensitivity to temozolomide (TMZ). Similar results were also observed in human glioma U373 cells. In addition, SalB aggravated the radiation-induced apoptosis and mitochondrial dysfunction, as measured by mitochondrial Ca²⁺ buffering capacity and mitochondrial swelling. SalB treatment markedly promoted mitochondrial fission and differently regulated the expression of fission proteins. Furthermore, downregulation of the fission protein Fis-1 using siRNA was found to partially reversed the SalB-induced effects on cell viability, apoptosis and mitochondrial fission in U87 cells. In conclusion, our results suggest that a subthreshold dose of SalB renders glioma cells more sensitive to radiation via Fis-1-mediated mitochondrial dysfunction, and radiotherapy combined with SalB might be a novel treatment for glioma patients.

A Changing of the Abbreviated Injury Scale that Improves Accuracy and Simplifies Scoring

Objective

We present here a changing of the abbreviated injury scale (AIS). It is called the changed injury severity score (CISS), and significantly outperforms the venerable but dated the injury severity score (ISS) and the new injury severity score (NISS) as a predictor of mortality.

Methods

The CISS is defined as a change of AIS values by raising each AIS severity score (1-6) by a power of 4.12 divided by 30.33 and then summing the three most severe (i.e. highest AIS) regardless of body regions. CISS values were calculated for every patient in two large independent data sets: 3455, 3900 patients treated during a five-year period at the class A grade III comprehensive hospitals in Affiliated Hospital of Hangzhou Normal University (Hangzhou) and Zhejiang Provincial People's Hospital (Zhejiang). The power of CISS to predict morality was then compared with previously calculated NISS values of the same group patients in the two hospitals.

Results

We found CISS was more accurate than NISS to predict the survival. The receiver operating characteristic (ROC) of NISS and CISS in Hangzhou were 0.919 and 0.937 respectively (p=0.026), whereas for Zhejiang were 0.917 and 0.940 respectively (p=0.022). Moreover, CISS provided a better fit throughout its entire range of prediction. Hosmer-Lemeshow (H-L) statistic for NISS and CISS in Hangzhou were 24.00 (p=0.002) and 19.38 (p=0.007), whereas in Zhejiang were 22.70 (p=0.001) and 18.43 (p=0.005) respectively.

Conclusions

CISS is a modified version of NISS/ISS with better statistical property and can be considered in trauma research.

Trephination mini-craniectomy for traumatic posterior fossa epidural hematomas in selected pediatric patients

PURPOSE

Posterior fossa epidural hematomas (PFEDH) are uncommon in children but usually require timely surgical intervention due to the risk of life-threatening brainstem compression. We attempt to make the surgical procedure less invasive by treating selected pediatric patients with trephination mini-craniectomy.

METHODS

We retrospectively reviewed the clinical courses, radiological findings, surgical procedures, and prognoses of the pediatric patients who were treated in our departments for traumatic PFEDH from January 2010 to January 2015.

RESULTS

During this period, a total of 17 patients were surgically treated for PFEDH and 7 were managed with trephination mini-craniectomy for hematoma evacuation. The outcomes were good in all 7 patients as evaluated with Glasgow Outcome Score. There was no mortality in this series. The on average 30-month clinical follow-up showed that patients experienced satisfactory recoveries without complications.

CONCLUSION

Our results suggest that trephination mini-craniectomy is a safe surgical technique for selected PFEDH patients with moderate hematoma volume and stabilized neurological functions. However, standard craniectomy is recommend when there are rapid deteriorations in patients' neurological functions or the hematomas are large and exerted severe mass effects.

Complementary and alternative interventions for fatigue management after traumatic brain injury: a systematic review

BACKGROUND

We systematically reviewed randomized controlled trials (RCTs) of complementary and alternative interventions for fatigue after traumatic brain injury (TBI).

METHODS

We searched multiple online sources including ClinicalTrials.gov, the Cochrane Library database, MEDLINE, CINAHL, Embase, the Web of Science, AMED, PsychINFO, Toxline, ProQuest Digital Dissertations, PEDro, PsycBite, and the World Health Organization (WHO) trial registry, in addition to hand searching of grey literature. The methodological quality of each included study was assessed using the Jadad scale, and the quality of evidence was evaluated using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. A descriptive review was performed.

RESULTS

Ten RCTs of interventions for post-TBI fatigue (PTBIF) that included 10 types of complementary and alternative interventions were assessed in our study. There were four types of physical interventions including aquatic physical activity, fitness-center-based exercise, Tai Chi, and aerobic training. The three types of cognitive and behavioral interventions (CBIs) were cognitive behavioral therapy (CBT), mindfulness-based stress reduction (MBSR), and computerized working-memory training. The Flexyx Neurotherapy System (FNS) and cranial electrotherapy were the two types of biofeedback therapy, and finally, one type of light therapy was included. Although the four types of intervention included aquatic physical activity, MBSR, computerized working-memory training and blue-light therapy showed unequivocally effective results, the quality of evidence was low/very low according to the GRADE system.

CONCLUSIONS

The present systematic review of existing RCTs suggests that aquatic physical activity, MBSR, computerized working-memory training, and blue-light therapy may be beneficial treatments for PTBIF. Due to the many flaws and limitations in these studies, further controlled trials using these interventions for PTBIF are necessary.

Development of user-friendly and interactive data collection system for cerebral palsy

Cerebral palsy (CP) is a permanent motor disorder that appears in early age and it requires multiple tests to assess the physical and mental capabilities of the patients. Current medical record data collection systems, e.g., EPIC, employed for CP are very general, difficult to navigate, and prone to errors. The data cannot easily be extracted which limits data analysis on this rich source of information. To overcome these limitations, we designed and prototyped a database with a graphical user interface geared towards clinical research specifically in CP. The platform with MySQL and Java framework is reliable, secure, and can be easily integrated with other programming languages for data analysis such as MATLAB. This database with GUI design is a promising tool for data collection and can be applied in many different fields aside from CP to infer useful information out of the vast amount of data being collected.

Single-Molecule Optical-Trapping Techniques to Study Molecular Mechanisms of a Replisome

The replisome is a multiprotein molecular machinery responsible for the replication of DNA. It is composed of several specialized proteins each with dedicated enzymatic activities, and in particular, helicase unwinds double-stranded DNA and DNA polymerase catalyzes the synthesis of DNA. Understanding how a replisome functions in the process of DNA replication requires methods to dissect the mechanisms of individual proteins and of multiproteins acting in concert. Single-molecule optical-trapping techniques have proved to be a powerful approach, offering the unique ability to observe and manipulate biomolecules at the single-molecule level and providing insights into the mechanisms of molecular motors and their interactions and coordination in a complex. Here, we describe a practical guide to applying these techniques to study the dynamics of individual proteins in the bacteriophage T7 replisome, as well as the coordination among them. We also summarize major findings from these studies, including nucleotide-specific helicase slippage and new lesion bypass pathway in T7 replication.

Retraction RETRACTION of "Methylation of the RASSFIA promoter in breast cancer" by Y. Ji, H.H. Jin, M.D. Wang, W.X. Cao, J.L. Bao - Genet. Mol. Res. 15 (2): gmr.15028261 (2016) - DOI: 10.4238/gmr.15028261

The retracted article is: Ji Y, Jin HH, Wang MD, Cao WX, et al. (2016). Methylation of the RASSFIA promoter in breast cancer. Genet. Mol. Res. 15: gmr.15028261. There are significant parts of this article (particularly, in the discussion section) that are copied from "Methylation of HIN-1, RASSF1A, RIL and CDH13 in breast cancer is associated with clinical characteristics, but only RASSF1A methylation is associated with outcome", by Jia Xu, Priya B Shetty, Weiwei Feng, Carol Chenault, Robert C Bast Jr, Jean-Pierre J Issa, Susan G Hilsenbeck and Yinhua Yu, published in BMC Cancer 2012; 12: 243. DOI: 10.1186/1471-2407-12-243. The first paragraphs of both discussions are identical. This is concerning. The abstract and introduction sections have much of their text plagiarized. Overall, there is high plagiarism detected. The GMR editorial staff was alerted and after a thorough investigation, we have strong reason to believe that the peer review process was failure and, after review and contacting the authors, the editors of Genetics and Molecular Research decided to retract the article in accordance with the recommendations of the Committee on Publication Ethics (COPE). The authors and their institutions were advised of this serious breach of ethics.

Localization of Anterosuperior Point of Transverse-sigmoid Sinus Junction Using a Reference Coordinate System on Lateral Skull Surface

Background:

During craniotomies using the transpetrosal-presigmoid approach, exposure of the sigmoid sinus remains an essential but hazardous step. In such procedures, accurate localization of the anterosuperior point of the transverse-sigmoid sinus junction (ASTS) is very important for reducing surgical morbidity. This study aimed to create an accurate and practical method for identifying the ASTS.

Methods:

On the lateral surfaces of 40 adult skulls (19 male skulls and 21 female skulls), a rectangular coordinate system was defined to measure the x and y coordinates of two points: the ASTS and the squamosal-parietomastoid suture junction (SP). With the coordinate system, the distribution characteristics of the ASTS were statistically analyzed and the differences between the ASTS and SP were investigated.

Results:

For ASTS-x, significant differences were found in different sides (P = 0.020); the ASTS-x in male skulls was significantly higher on the right side (P = 0.017); there was no significant difference between the sides in female skulls. There were no significant differences in gender or interaction of gender and side for ASTS-x, and for ASTS-y, there were no significant differences in side, gender, or interaction of gender and side. For both sides combined, the mean ASTS-x was significantly higher than the mean SP-x (P = 0.003) and the mean ASTS-y was significantly higher than the mean SP-y (P = 0.011).

Conclusions:

This reference coordinate system may be an accurate and practical method for identifying the ASTS during presigmoid craniotomy. The SP might be difficult to find during presigmoid craniotomy and, therefore, it is not always a reliable landmark for defining the ASTS.

Methylation of the RASSFIA promoter in breast cancer

Tumor suppressor genes are the key targets of hypermethylation in breast cancer and may therefore lead to malignancy by deregulation of cell growth and division. Our previous pilot study with pairs of malignant and normal breast tissues identified a correlation between RASSFIA gene methylation and breast cancer. To determine the relationship between RASSFIA methylation and breast cancer, we conducted a larger study. We took samples from 108 patients with breast cancer, 28 patients with benign breast tumors, and 33 subjects with normal breast tissues at the Second Affiliated Hospital of Nanjing Medical University at Wuxi between July 2013 and September 2015. We used the samples to investigate methylation levels of the RASSF1A gene for associations with breast cancer. Quantitative real-time polymerase chain reaction (PCR) and methylation-specific PCR were used to investigate the levels of RASSF1A mRNA expression and RASSF1A methylation, respectively. RASSFIA was not expressed in 22 of the 108 breast cancer tissue samples (20.37%), and there was no statistically significant difference (P > 0.05); however, RASSFIA expression was significantly lower than that in the normal breast tissue samples (P < 0.05). Moreover, the methylation rate of the RASSFIA gene promoter was significantly higher in the breast cancer tissues (64.81%) than in the normal breast tissues (18.18%) and benign breast tumors (17.86%) (P < 0.05). High methylation of the RASSF1A gene promoter was an important reason for its downregulation, and the gene played a critical regulated role in the incidence and development of breast cancer.

Emerging role of microRNA-27a in human malignant glioma cell survival via targeting of prohibitin

MicroRNAs (miRs) function as oncogenes and tumor suppressors, and have roles in most cellular processes. To date, the possible role of miR-27a, which is part of the miR-23a/27a/24-2 cluster, in malignant gliomas has remained elusive. Therefore, the present study aimed to explore the role of miR-27a in glioma and its potential target. Through transfection with miR-27a inhibitor or oligonucleotide mimics, the impact of miR-27a silencing or overexpression on the growth, apoptosis, cell cycle and invasiveness of U251 and U87MG cells was examined in vitro. The present study initially identified the potential target of miR-27a in glioma cells through a bioinformatics analysis, which was used for screening of the literature on the proteomics of gliomas. Prohibitin (PHB) was then confirmed as a target by absolute luciferase reporter assays, quantitative real-time polymerase chain reaction and western blot analysis. Treatment with miR-27a mimics oligonucleotides suppressed U251 cell proliferation, promoted apoptosis by inducing G2/M phase arrest, and impaired the invasive potential of U251 cells in vitro. In addition, miR-27a expression was downregulated in glioma tissues. A PHB-3'-untranslated region luciferase reporter assay confirmed PHB as a direct target gene of miR-27a. PHB mRNA expression was reversely correlated with levels of miR-27a in U251 cells. Overexpression of miR-27a in U251 cells at 72 h and 96 h post‑transfection with miR-27a mimics significantly decreased PHB protein expression by 17.2% and 43.9%, respectively. In conclusion, miR-27a was shown to be a significant tumor suppressor by targeting and decreasing PHB protein expression in glioma U251 cells. miR-27a targeting of PHB may be a novel potential therapeutic strategy for glioma.

Med-vest: A wearable sensory platform

Sickle cell disease is a genetic mutation that causes sickling of the red blood cells, affecting between 90,000 and 100,000 Americans. Researchers must develop methods of data acquisition capable of maximizing both the amount of data being collected and types of data being collected to form the most accurate diagnosis and treatment for patients. Popular data acquisition forms are the use of mobile phones, sensory systems, and wearable technology. In this paper, we attempt to bridge the gap between the three, combining a wearable sensory system with the computation and communication power of mobile phones. We propose the application of sickle cell disease as a structure around which to design a textile-based data acquisition system.

IDH1 overexpression induced chemotherapy resistance and IDH1 mutation enhanced chemotherapy sensitivity in Glioma cells in vitro and in vivo

Isocitrate dehydrogenase (IDH) is of great importance in cell metabolism and energy conversion. IDH mutation in glioma cells is reported to be associated with an increased overall survival. However, effects biological behavior of therapy of gliomas are unclear. Here, we investigated the influence of wild-type and mutated IDH genes on glioma cell biological behavior and response to chemotherapy. Relevant mechanisms were further explored. We designed our study on the background of the IDHR132H mutation. Stable cell lines were constructed by transfection. The CCK-8 method was used to assess cell proliferation, flow cytometry for the cell cycle and cell apoptosis, and the transwell method for cell invasion. Nude mouse models were employed to determine tumorigenesis and sensitivity to chemotherapy. Western blotting was used to detect relevant protein expression levels. We found that overexpression of wild IDH1 gene did not cause changes in the cell cycle, apoptosis and invasion ability. However, it resulted in chemotherapy resistance to a high dose of temozolomide (TMZ) in vivo and in vitro. The IDH1 mutation caused cell cycle arrest in G1 stage and a reduction of proliferation and invasion ability, while raising sensitivity to chemotherapy. This may provide an explanation for the better prognosis of IDH1 mutated glioma patients and the relative worse prognosis of their wild-type IDH1 counterparts. We also expect IDH1 mutations may be optimized as new targets to improve the prognosis of glioma patients.

Development of a laboratory information system for cancer collaboration projects

Technological advances increase the rate and quality of biomedical data collection. To exploit these advances to the fullest, laboratory information management systems (LIMS) have been developed to integrate laboratory equipment with software controls so as to achieve an automated and seamless workflow process. Ultimately, researchers and clinicians must collaborate closely to achieve a comprehensive interpretation of heterogeneous biomedical data, especially with respect to clinical diagnosis and treatment. We present eOncoLIMS, a modular data and process management system designed to provide the infrastructure and environment for a collaborative cancer research project. This system can be further extended to other collaboration projects to achieve a complete solution to research and clinical problems.

Advances in molecular classification of renal neoplasms

Kidney neoplasms are classified by light microscopy using the World Health Organization (WHO) system. The WHO system defines histopathologic tumor subtypes with distinct clinical behavior and underlying genetic mutations. In adults, the common malignant subtypes are variants of renal cell carcinoma (RCC). Histopathologic classification is critical for clinical management of RCC, but is becoming more complex with recognition of novel tumor subtypes, development of procedures yielding small diagnostic biopsies, and emergence of molecular therapies directed at tumor gene activity. Therefore, classification systems based on gene expression are likely to become essential for diagnosis, prognosis and treatment of kidney tumors. Recent DNA microarray studies have shown that clinically relevant renal tumor subtypes are characterized by distinct gene expression profiles, which are useful for discovery of novel diagnostic and prognostic biomarkers. In this review, we summarize the WHO classification system for renal tumors, general applications of microarray technology in cancer research, and specific microarray studies that have advanced knowledge of renal tumor diagnosis, prognosis, therapy and pathobiology.

Serotonin 5-HT(1A) receptor mRNA expression in dorsal hippocampus and raphe nuclei after gonadal hormone manipulation in female rats

Female ovarian steroids influence mood and cognition, an effect presumably mediated by the serotonergic system. A key receptor in this interplay may be the 5-HT(1A) receptor subtype. We gave adult ovariectomized female rats subcutaneous pellets containing different dosages of 17 beta-estradiol alone or in combination with progesterone, or placebo pellets, for 2 weeks. 5-HT(1A) receptor mRNA levels were analyzed by in situ hybridization in the dorsal hippocampus, dorsal and median raphe nuclei, and entorhinal cortex. Estradiol treatment alone reduced 5-HT(1A) gene expression in the dentate gyrus and the CA2 region (17 and 19% decrease, respectively). Estradiol combined with progesterone supplementation increased 5-HT(1A) gene expression versus placebo in the CA1 and CA2 subregions of the dorsal hippocampus (16 and 30% increase, respectively). Concomitantly, 5-HT(1A) mRNA expression was decreased by 13% in the ventrolateral part of the dorsal raphe nuclei, while no changes were found in the median raphe nucleus and entorhinal cortex. Chronic effects of ovarian hormones on 5-HT(1A) receptor mRNA expression appear tissue-specific and involve hippocampal subregions and the raphe nuclei. Modulation of 5-HT(1A) receptor gene expression may be of importance for gonadal steroid effects on mood and cognition.

The functional role of a bicuculline-sensitive Ca2+-activated K+ current in rat medial preoptic neurons

A Ca2+-activated K+ current was identified in neurons from the rat medial preoptic nucleus. Its functional role for the resting potential and for impulse generation was characterised by using the reversible blocking agent bicuculline methiodide. Acutely dissociated neurons were studied by perforated-patch recordings. The effect of bicuculline methiodide was investigated under voltage-clamp conditions to clearly identify the current affected. At membrane potentials > -50 mV, bicuculline methiodide rapidly (< 1 s) and reversibly blocked a steady outward current. Half-saturating concentration was 12 microM. The current amplitude increased with potential in the range -50 to 0 mV. The bicuculline-sensitive current was identified as an apamin-sensitive, Ca2+-dependent K+ current. It was neither affected by the GABAA receptor blocker picrotoxin (100 microM) nor by a changed pipette Cl- concentration, but was affected by substitution of extracellular K+ for Na+. The current was dependent on extracellular Ca2+ and was sensitive to 1 microM apamin but not to 200 nM charybdotoxin. A role for the Ca2+-dependent K+ current in setting the resting potential and controlling spontaneous firing frequency was observed under current-clamp conditions. Bicuculline methiodide (100 microM) induced a positive shift (5 +/- 1 mV; n = 18) of resting potential in all neurons tested. In the majority of spontaneously firing neurons, the firing frequency was reversibly affected, either increased or decreased depending on the cell, by bicuculline methiodide.

Evaluation and comparison of the pharmacokinetic and pharmacodynamic properties of allopregnanolone and pregnanolone at induction of anaesthesia in the male rat

We have evaluated and compared the pharmacokinetic and pharmacodynamic properties of allopregnanolone and pregnanolone at induction of anaesthesia in male rats. A threshold method was used, and the first burst suppression period of 1 s or more in the EEG was selected as the end-point after fairly slow infusions. An optimal dose of 4.0 mg kg(-1) min(-1) was noted for both steroids. Brain concentrations were low at low infusion rates, indicating that acute tolerance was not occurring. Significant positive correlations were noted between dose rate and serum concentrations of allopregnanolone (r = 0.94, P<0.001) and pregnanolone (r = 0.88, P<0.001). Such correlations were also seen in striatum, cerebellum, cortex and muscle for both steroids (P<0.01). Despite changing infusion rates, the concentrations of both steroids in brainstem, hippocampus and fat remained stable. Because no correlation between infusion rate and steroid concentration was noted in the brainstem and hippocampus, these two brain areas may be regarded as primary sites of action for allopregnanolone and pregnanolone. Pregnanolone concentrations in the brainstem and hippocampus were significantly higher than those of allopregnanolone, suggesting that allopregnanolone was more potent than pregnanolone in inducing anaesthesia.

The inhibitory effects of allopregnanolone and pregnanolone on the population spike, evoked in the rat hippocampal CA1 stratum pyramidale in vitro, can be blocked selectively by epiallopregnanolone

The progesterone metabolites allopregnanolone (Allo, 3alpha-hydroxy-5alpha-pregnan-20-one) and pregnanolone (Preg, 3alpha-hydroxy-5beta-pregnan-20-one) enhance the gamma-aminobutyric acid (GABA) action through a distinct site on the GABAA-receptor. Their 3beta-isomers epiallopregnanolone (Epiallo, 3beta-hydroxy-5alpha-pregnan-20-one) and epipregnanolone (Epipreg, 3beta-hydroxy-5beta-pregnan-20-one), do not have these effects on GABAA-receptors. We have studied the interaction between Allo/Preg and their 3beta-isomers on action potentials in rat hippocampal slices in vitro. The Schaffer collaterals were stimulated electrically in CA1 striatum radiatum and the population spike (POPSP) was recorded in stratum pyramidale. A 0.5-nL droplet of drug was applied locally onto stratum oriens-pyramidale via a pressure pipett. Muscimol (Mus) (12.5 fmol), Allo and Preg (6.25 fmol) caused a reversible inhibition of POPSP. On the other hand, 6.25 fmol Epiallo had no significant effect on POPSP compared with the vehicle control. Combined Epiallo and Allo application caused a dose-dependent reduction of the Allo inhibition of POPSP. A full blockage was seen at a molar ratio of 1:1. Epiallo also blocked the Preg inhibition of POPSP, when the two drugs were combined in a molar ratio of 1:1. Epiallo did not block the Mus inhibition of POPSP, when the two drugs were combined at a molar ratio of 1:2. Bath perfusion of 12.5 microM Epiallo blocked the inhibition of 6.25 fmol Allo on POPSP, but not the inhibition caused by 12.5 fmol Mus. Epipreg did not block the inhibition of Allo and Preg on POPSP, when it was combined with the two latter drugs at a molar ratio of 1:1. Our data suggest that the steroid modulation of the GABAA transmitted inhibition of the CA1 pyramidal neurones is selectively and dose dependently blocked by Epiallo, the 3beta-hydroxy-isomer of Allo, but not by Epipreg, the 3beta-hydroxy-isomer of Preg.

gammadelta T-cell-deficient mice do not differ from normal controls in their induction or expression of type 2 dominant responses to exogenous antigen

The roles that gammadelta T cells play in shaping initial CD4 T cell activation, and sensitivity to development of atopic diseases, remain controversial. Using a genetic knockout model of gammadelta T-cell deficiency, we investigated the role of these cells in initiation of exogenous antigen specific murine cytokine and antibody responses. Given that the most widely distributed and clinically prominent class of allergens are soluble protein antigens, we utilized OVA to examine the role played by gammadelta T cells in shaping the induction and expression of exogenous Ag specific immune responses. Focusing on immunization conditions that stimulate in vivo induction of type 2 dominant immunity, we report that gammadelta deficient and intact C57Bl6 mice exhibit similar OVA-specific responses as indicated by the (i) intensity of initial T-cell activation (ii) the type1 vs. type 2 balance of exogenous Ag specific cytokine synthesis and the (iii) intensity and the relative balance of the resulting IgE vs. IgG(2a) responses in vivo seen in these strains. Taken together, the data are consistent with the hypothesis that gammadelta T cells do not play an essential role in shaping induction of systemic immune responses to soluble exogenous antigen in type 2 dominated responses.

Failure of rIL-12 administration to inhibit established IgE responses in vivo is associated with enhanced IL-4 synthesis by non-B/non-T cells

Administration of rIL-12 offers a widely successful tactic for preferential induction of type 1 immune responses in vivo. Its use to modulate ongoing cytokine or effector responses has proven to be substantially more difficult. Immediate hypersensitivity is the most common human immunologic disease. Here, rIL-12 was administered to C57Bl/6 and outbred CD1 mice with ongoing ovalbumin (OVA)-specific IgE responses in an attempt to redirect established type 2 cytokine and antibody production. Despite use of a broad range of treatment protocols for >4 months following initial immunization, recall IgE responses were consistently unaffected. rIL-12-treated mice exhibited strong in vivo and in vitro IFN-gamma responses, increased approximately 40-fold relative to controls, but also markedly enhanced (15- to 20-fold) OVA-specific IL-4 production. CD4 T cell function was successfully transformed from a type 2- to a type 1-dominated pattern following long-term IL-12 administration in vivo, as measured by strongly reduced IL-4 and IL-10 responses in antigen-stimulated primary culture, and 5-fold reductions in the frequencies of IL-4- and IL-10-producing OVA-specific CD4 T cells. However, chronically rIL-12-treated mice exhibited increased numbers of non-B/non-T cells that when re-stimulated with specific allergen, produce IL-4 at levels 20-fold higher than did CD4 T cells while IL-13 responses are unaffected. Collectively, the data indicate that even effectively shifting CD4 T cell activation from a type 2- to a type 1-dominated response does not in itself lead to altered effector (IgE) responses upon antigen re-exposure.

Stretching of single collapsed DNA molecules

The elastic response of single plasmid and lambda phage DNA molecules was probed using optical tweezers at concentrations of trivalent cations that provoked DNA condensation in bulk. For uncondensed plasmids, the persistence length, P, decreased with increasing spermidine concentration before reaching a limiting value 40 nm. When condensed plasmids were stretched, two types of behavior were observed: a stick-release pattern and a plateau at approximately 20 pN. These behaviors are attributed to unpacking from a condensed structure, such as coiled DNA. Similarly, condensing concentrations of hexaammine cobalt(III) (CoHex) and spermidine induced extensive changes in the low and high force elasticity of lambda DNA. The high force (5-15 pN) entropic elasticity showed worm-like chain (WLC) behavior, with P two- to fivefold lower than in low monovalent salt. At lower forces, a 14-pN plateau abruptly appeared. This corresponds to an intramolecular attraction of 0.083-0.33 kT/bp, consistent with osmotic stress measurements in bulk condensed DNA. The intramolecular attractive force with CoHex is larger than with spermidine, consistent with the greater efficiency with which CoHex condenses DNA in bulk. The transition from WLC behavior to condensation occurs at an extension about 85% of the contour length, permitting looping and nucleation of condensation. Approximately half as many base pairs are required to nucleate collapse in a stretched chain when CoHex is the condensing agent.

IL-12 administered during Chlamydia psittaci lung infection in mice confers immediate and long-term protection and reduces macrophage inflammatory protein-2 level and neutrophil infiltration in lung tissue

Protection against infections with the intracellular bacterium Chlamydia spp. requires Th1-polarized CD4+ T cell immunity. In BALB/c mouse lung infections, immediate innate and nascent Chlamydia-specific immune responses following intranasal inoculation of Chlamydia psittaci strain B577 were modulated by 7-day i.p. administration of murine rIL-12, the initiation cytokine for Th1 immunity. Treatment with IL-12 reduced the severity of chlamydial pneumonia, abolished mortality (37.5% in untreated mice), and significantly reduced numbers of chlamydial organisms in lungs. On day 4 after inoculation, the neutrophil:macrophage ratio in bronchointerstitial pneumonias was 1.96 in untreated mice and 0.51 in IL-12-treated mice. This immediate, IL-12-mediated shift in innate inflammatory phenotype was correlated with a significant reduction of lung concentrations of the neutrophil chemoattractant macrophage inflammatory protein (MIP)-2 (putative murine homologue of human IL-8), monocyte chemotactic protein-1, and TNF-alpha; and a reduction in MIP-1alpha and IFN-gamma, at high-dose infection only, and IL-12-independent IL-10 levels. Chlamydia-specific Ab titers and Ig isotype ratios indicated an IL-12-dependent Th1 shift. Recall responses of IL-12-primed mice to secondary chlamydial lung infection eliminated chlamydiae more effectively and generated a lung cytokine profile conducive to perpetuation of the Th1 memory population. These data support the hypothesis that genetic differences in endogenous IL-12 production and response pathways could determine disease outcomes characterized by poor chlamydial clearance and a purulent inflammatory infiltrate vs effective elimination of chlamydiae in a macrophage-dominated response.

Manipulation of single molecules in biology

The mechanical manipulation of single biological molecules is stimulating new and exciting research in many fields of study, including molecular motor mechanics, biopolymer properties, protein unfolding, receptor-ligand interactions, and more. Some recent highlights include the elucidation of the coupling ratios of myosin and kinesin, the demonstration of oscillatory forces in dynein arms, the determination of the force-velocity relation of RNA polymerase, and the direct mechanical observation of unfolding of single domains of titin and tenascin.

Estimating the persistence length of a worm-like chain molecule from force-extension measurements

We describe a simple computation of the worm-like chain model and obtain the corresponding force-versus-extension curve. We propose an improvement to the Marko and Siggia interpolation formula of Bustamante et al (Science 1994, 265:1599-1600) that is useful for fitting experimental data. We apply it to the experimental elasticity curve of single DNA molecules. Finally, we present a tool to study the agreement between the worm-like chain model and experiments.

Force and velocity measured for single molecules of RNA polymerase

RNA polymerase (RNAP) moves along DNA while carrying out transcription, acting as a molecular motor. Transcriptional velocities for single molecules of Escherichia coli RNAP were measured as progressively larger forces were applied by a feedback-controlled optical trap. The shapes of RNAP force-velocity curves are distinct from those of the motor enzymes myosin or kinesin, and indicate that biochemical steps limiting transcription rates at low loads do not generate movement. Modeling the data suggests that high loads may halt RNAP by promoting a structural change which moves all or part of the enzyme backwards through a comparatively large distance, corresponding to 5 to 10 base pairs. This contrasts with previous models that assumed force acts directly upon a single-base translocation step.

Interaction between 3 alpha-hydroxy-5 alpha-pregnan-20-one and carbachol in the control of neuronal excitability in hippocampal slices of female rats in defined phases of the oestrus

The effects of 3 alpha-hydroxy-5 alpha-pregnan-20-one (allopregnanolone) and carbachol on CA1 and dentate gyrus action potentials were studied in hippocampus slices in premature, follicular and luteal phase rats. A 0.5 nL droplet of allopregnanolone (12.5 mumol L-1), carbachol (5 mumol L-1) or a mixed solution of 12.5 mumol L-1 allopregnanolone and 5 mumol L-1 carbachol was applied locally onto the stratum oriens-pyramidale or granular layer. The amplitude of CA1 population spike (POPSP) was reduced by allopregnanolone (-38 +/- 3%) and carbachol (-21 +/- 4%) in the luteal phase slices. The mixture of allopregnanolone and carbachol doubled this inhibition (-77 +/- 6%). The inhibition caused by allopregnanolone and the mixture of allopregnanolone and carbachol in CA1 was significantly larger in the luteal phase than in the follicular phase (P = 0.02 and 0.0002). In the granular layer of the dentate gyrus, these inhibitions showed no significant difference between the phases. Neither in CA1 nor in the dentate gyrus did the carbachol inhibition differ between the phases. Perfusion with 5-10 mumol L-1 carbachol caused an increasing inhibition of the POPSP during the first few minutes. Thereafter the inhibition gradually diminished and was replaced by a facilitation. The local allopregnanolone inhibition was enhanced by simultaneous carbachol perfusion. Picrotoxin (100 mumol L-1) substantially reduced the allopregnanolone but not the carbachol inhibition. Atropine (10 mumol L-1) blocked the carbachol response, but not the allopregnanolone inhibition. Perfusion with a mixed solution of picrotoxin and atropine reduced, but did not block, the inhibition caused by local application of allopregnanolone or by the mixture of allopregnanolone and carbachol. Our data suggest that neuroprogestine modulators of the GABAA-receptor-mediated inhibition may play a significant role in the control of the cholinergic excitation in the hippocampus.

Immune suppression by lysosomotropic amines and cyclosporine on T-cell responses to minor and major histocompatibility antigens: does synergy exist?

BACKGROUND

Using murine models, we have shown that the lysosomotropic amine, chloroquine, is effective in the prevention of graft-versus-host disease (GVHD) mediated by donor T cells reactive with recipient minor histocompatibility antigens (MiHCs). Because lysosomotropic amines can suppress major histocompatibility complex (MHC) class II antigen presentation, their mechanism of action is potentially different from current immune suppressant drugs used to control GVHD such as cyclosporine.

METHODS

We investigated the use of cyclosporine and the lysosomotropic amines chloroquine and hydroxychloroquine in combination for additive or synergistic immunosuppression on T-cell responses in vitro to MiHC and MHC in mice.

RESULTS

We found that similar concentrations of chloroquine and hydroxychloroquine suppress the T-cell response to MiHC in mice (C57BL/6 anti-BALB.B) and that lysosomotropic amines in combination with cyclosporine result in synergistic suppression of a proliferative response to MiHC. Similar suppression and synergy appear to be present in an alloreactive response (C57BL/6 anti-BALB/c). Direct inhibition by chloroquine of T-cell proliferative responses induced by anti-CD3epsilon in the absence of antigen-presenting cells is present at higher concentrations than that required to suppress responses to MiHC or MHC. Chloroquine appears to induce decreased T-cell viability at high concentrations. This effect does not appear to be due to decreased T-cell production of interleukin-2 or interferon-gamma. At lower concentrations (<25 microg/ml), chloroquine can also decrease the ability of antigen-presenting cells to stimulate an a C57BL/6 anti-BALB/c T-cell response and can inhibit MHC class II expression after activation with lipopolysaccharide.

CONCLUSIONS

Lysosomotropic amines in combination with cyclosporine appear to be synergistic in the suppression of T-cell proliferation to MiHC and MHC. Use of chloroquine in combination with cyclosporine may result in improved control of GVHD.

The regional brain distribution of the neurosteroids pregnenolone and pregnenolone sulfate following intravenous infusion

We have studied the distribution of the neurosteroids pregnenolone (Pe) and pregnenolone sulfate (PeS) in seven brain regions, and plasma and fat tissues in male adult rats following the intravenous infusion of 14 mg/kg Pe and 18 mg/kg PeS, respectively. After chromatographic separation of steroid sulfate esters and non-conjugated steroids by solid phase octadecyl C18 columns and celite column chromatographic separation of Pe from cross-reacted steroids, the concentrations of Pe and PeS were determined by radioimmunoassay. We found that both Pe and PeS concentrations were significantly increased in plasma, fat and brain compared to the vehicle controls after i.v. infusion of Pe and PeS. In the controls, Pe concentrations were highly correlated within brain regions and between fat and brain regions. Most correlations were lost after Pe and PeS infusions. The content of Pe and PeS was not uniformly distributed in the brain. The hypothalamus contained the highest level of Pe in controls, Pe-infused and PeS-infused rats (12 +/- 3.1, 3500 +/- 180 and 590 +/- 54 ng/g, respectively). The highest concentration of PeS was detected in the hypothalamus (26 +/- 8.2 ng/g) and striatum (17 +/- 4.1 ng/g) in controls, in the hypothalamus (200 +/- 24 ng/g) after PeS infusion as well as in the hypothalamus and medulla oblongata (57 +/- 9.6 and 55 +/- 7.6 ng/g, respectively) after Pe infusion. This study has yielded evidence that PeS injected i.v. can cross the blood-brain barrier without being hydrolysed to the more lipophilic Pe, and can thus be taken up by the brain.

Stretching DNA with optical tweezers

Force-extension (F-x) relationships were measured for single molecules of DNA under a variety of buffer conditions, using an optical trapping interferometer modified to incorporate feedback control. One end of a single DNA molecule was fixed to a coverglass surface by means of a stalled RNA polymerase complex. The other end was linked to a microscopic bead, which was captured and held in an optical trap. The DNA was subsequently stretched by moving the coverglass with respect to the trap using a piezo-driven stage, while the position of the bead was recorded at nanometer-scale resolution. An electronic feedback circuit was activated to prevent bead movement beyond a preset clamping point by modulating the light intensity, altering the trap stiffness dynamically. This arrangement permits rapid determination of the F-x relationship for individual DNA molecules as short as -1 micron with unprecedented accuracy, subjected to both low (approximately 0.1 pN) and high (approximately 50 pN) loads: complete data sets are acquired in under a minute. Experimental F-x relationships were fit over much of their range by entropic elasticity theories based on worm-like chain models. Fits yielded a persistence length, Lp, of approximately 47 nm in a buffer containing 10 mM Na1. Multivalent cations, such as Mg2+ or spermidine 3+, reduced Lp to approximately 40 nm. Although multivalent ions shield most of the negative charges on the DNA backbone, they did not further reduce Lp significantly, suggesting that the intrinsic persistence length remains close to 40 nm. An elasticity theory incorporating both enthalpic and entropic contributions to stiffness fit the experimental results extremely well throughout the full range of extensions and returned an elastic modulus of approximately 1100 pN.

Pregnenolone sulphate and pregnenolone do not interact with 5 beta-pregnanolone- and hexobarbitone-induced anaesthesia in the rat

We have studied the interaction of pregnenolone sulphate and pregnenolone with 5 beta-pregnanolone- and hexobarbitone-induced anaesthesia in male rats using an EEG threshold method. Burst suppression of the EEG of 1 s or more ("silent second" (SS)), was used as a criterion of deep anaesthesia. The effects of the steroid solvents albumin and beta-cyclodextrin were assessed by dose-response curves. Despite a significant increase in hexobarbitone threshold dose in relation to increased doses of albumin, there was no correlation between albumin dose and hexobarbitone concentrations in serum, fat and brain tissues. There was no significant difference in threshold concentrations of hexobarbitone between controls given albumin and those pretreated with pregnenolone. In subsequent experiments, 20% beta-cyclodextrin was used as steroid solvent and its volume was maintained at less than 3.0 ml kg-1 during pretreatment. Neither pregnenolone sulphate nor pregnenolone significantly altered the potency of 5 beta-pregnanolone for induction of anaesthesia. Furthermore, there was no interaction of pregnenolone sulphate and pregnenolone on induction of anaesthesia when hexobarbitone was used for anaesthesia.

Transcription against an applied force

The force produced by a single molecule of Escherichia coli RNA polymerase during transcription was measured optically. Polymerase immobilized on a surface was used to transcribe a DNA template attached to a polystyrene bead 0.5 micrometer in diameter. The bead position was measured by interferometry while a force opposing translocation of the polymerase along the DNA was applied with an optical trap. At saturating nucleoside triphosphate concentrations, polymerase molecules stalled reversibly at a mean applied force estimated to be 14 piconewtons. This force is substantially larger than those measured for the cytoskeletal motors kinesin and myosin and exceeds mechanical loads that are estimated to oppose transcriptional elongation in vivo. The data are consistent with efficient conversion of the free energy liberated by RNA synthesis into mechanical work.

[Inhibition of sodium artesunate on rat erythrocyte membrane Na(+)-K(+)-exchanging ATPase in vitro]

AIM

To study the effects of sodium artesunate (SA) on Na(+)-K(+)-exchanging ATPase activity of rat erythrocyte membrane in vitro.

METHODS

SA of different concentrations (0, 0.5, 1, 5 and 10 mumol . L-1) were added respectively in the reaction system. The Na(+)-K(+)-exchanging ATPase activity was calculated by measuring the amount of inorganic phosphate released in the reaction system.

RESULTS

Along with the increase of SA concentration (0, 0.5, 1, 5 and 10 mumol . L-1), the Na(+)-K(+) -exchanging ATPase activity decreased, the inhibitory rates were 15%, 29%, 46%, and 75%, respectively. Increasing the concentration of substrate ATP to 125, 250, 375 and 500 mumol . L-1 and determining the kinetics of enzyme. Making the Eadie-Hofstee kinetic curve by linear-regression analysis. The result revealed that the inhibitory effect of SA on the enzyme was competitive.

CONCLUSION

SA affected the ion transfer of host erythrocyte membrane and membrane function.

Team development and memory training in traumatic brain injury rehabilitation: two birds with one stone

The need for developing team cooperation procedures when treating patients with traumatic brain injury (TBI) is stated. One approach in promoting team cooperation is to combine team development with a specific training programme. A memory training programme used in a subacute TBI rehabilitation unit is described. A combination of a team development procedure and memory training programme was performed in the unit. A questionnaire to assess team members' attitudes to team cooperation was administered before and after team development, and memory training procedures were implemented. The post-training questionnaire administration indicated a more positive perception among team members of how the team functioned. The efficacy of memory training showed variable results. The programme described may illustrate the advantages of combining a specific treatment programme with efforts to promote team development.

Potency of lipid and protein formulation of 5 alpha-pregnanolone at induction of anaesthesia and the corresponding regional brain distribution

We have studied the anaesthetic potencies of 5 alpha-pregnanolone albumin solution (PAS) and 5 alpha-pregnanolone Intralipid emulsion (PLE) at equivalent concentrations in male rats using an EEG threshold method. The criterion of anaesthesia was burst suppression of the EEG of 1 s or more (the "silent second" (SS)) as a sign of deep anaesthesia. The potency of the two formulations was assessed by comparing the threshold doses of 5 alpha-pregnanolone at three dose rates (1.0, 2.0 and 3.0 mg kg-1 min-1). We found that SS was initiated in all rats after infusions of PAS, while no SS could be induced in rats after infusion of PLE at a larger dose. A higher concentration of 5 alpha-pregnanolone was found in all brain and peripheral tissues of PAS-treated rats than in those treated with PLE. In rats with PAS-induced anaesthesia (3.0 mg kg-1 min-1), the highest concentrations were detected in striatum (mean 19.40 (SD 1.21) ng mg-1). Although there was a small insignificant reduction in threshold doses with dose rates at 2.0-3.0 mg kg-1 min-1, the tissue concentrations in striatum, frontal cortex and occipital cortex were found to be significantly increased. We conclude that PAS was more potent than PLE in inducing anaesthesia. Brain distribution of 5 alpha-pregnanolone varied regionally in a manner similar to the variation in GABAA receptor sensitivity to this neuroactive steroid.

Time-lapse total internal reflection fluorescence video of acetylcholine receptor cluster formation on myotubes

To study when and where acetylcholine receptor (AChR) clusters appear on developing rat myotubes in primary culture, we have made time-lapse movies of total internal reflection fluorescence (TIRF) overlaid with schlieren transmitted light images. The receptors, including the ones newly incorporated into the membrane, were labeled with rhodamine alpha-bungarotoxin (R-BT) continuously present in the medium. Since TIRF illuminates only cell-substrate contact regions where almost all of the AChR clusters are located, background fluorescence from fluorophores either in the bulk solution or inside the cells can be suppressed. Also, because TIRF minimizes the exposure of the cell interior to light, the healthy survival of the culture during imaging procedures is much enhanced relative to standard epi- (or trans-) illumination. During the experiment, cells were kept alive on the microscope stage at 37 degrees C in an atmosphere of 10% CO2. Two digital images were recorded by a CCD camera every 20 min: the schlieren image of the cells and the TIRF image of the clusters. After background subtraction, the cluster image was displayed in pseudocolors, overlaid onto the cell images, and recorded as 3 frames on a videotape. The final movies are thus able to summarize a week-long experiment in less than a minute. These movies and images show that clusters form often shortly after the myoblast fusion but sometimes much later, and the formation takes place very rapidly (a few hours). The clusters have an average lifetime of around a day, much shorter than the lifetime of a typical myotube. The brightest and largest clusters tend to be the longest-lived. The cluster formation seems to be associated with the contacts of myotubes at the glass substrate, but not with cell-cell contacts or myoblast fusion into myotubes. New AChR continuously appear in preexisting clusters: after photobleaching, the fluorescence of some clusters recovers within an hour.