Bispecific fibrous glue synergistically boosts vascular normalization and antitumor immunity for advanced renal carcinoma therapy

Immune checkpoint blockade therapy represented by programmed cell death ligand 1 (PD-L1) inhibitor for advanced renal carcinoma with an objective response rate (ORR) in patients is less than 20%. It is attributed to abundant tumoral vasculature with abnormal structure limiting effector T cell infiltration and drug penetration. We propose a bispecific fibrous glue (BFG) to regulate tumor immune and vascular microenvironments simultaneously. The bispecific precursor glue peptide-1 (pre-GP1) can penetrate tumor tissue deeply and self-assemble into BFG in the presence of neuropilin-1 (NRP-1) and PD-L1. The resultant fibrous glue is capable of normalizing tumoral vasculature as well as restricting immune escape. The pre-GP1 retains a 6-fold higher penetration depth than that of antibody in the multicellular spheroids (MCSs) model. It also shows remarkable tumor growth inhibition (TGI) from 19% to 61% in a murine advanced large tumor model compared to the clinical combination therapy. In addition, in the orthotopic renal tumor preclinical model, the lung metastatic nodules are reduced by 64% compared to the clinically used combination. This pre-GP1 provides a promising strategy to control the progression and metastasis of advanced renal carcinoma.

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.

Structure and dynamics of endogenous cardiac troponin complex in human heart tissue captured by native nanoproteomics

Protein complexes are highly dynamic entities that display substantial diversity in their assembly, post-translational modifications, and non-covalent interactions, allowing them to play critical roles in various biological processes. The heterogeneity, dynamic nature, and low abundance of protein complexes in their native states present challenges to study using conventional structural biology techniques. Here we develop a native nanoproteomics strategy for the enrichment and subsequent native top-down mass spectrometry (nTDMS) analysis of endogenous cardiac troponin (cTn) complex directly from human heart tissue. The cTn complex is enriched and purified using peptide-functionalized superparamagnetic nanoparticles under non-denaturing conditions to enable the isotopic resolution of cTn complex, revealing their complex structure and assembly. Moreover, nTDMS elucidates the stoichiometry and composition of the cTn complex, localizes Ca2+ binding domains, defines cTn-Ca2+ binding dynamics, and provides high-resolution mapping of the proteoform landscape. This native nanoproteomics strategy opens a paradigm for structural characterization of endogenous native protein complexes.

[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.

An In Vivo Self-Assembled Bispecific Nanoblocker for Enhancing Tumor Immunotherapy

Anti-PD-L1 monoclonal antibody has achieved substantial success in tumor immunotherapy by T-cells activation. However, the excessive accumulation of extracellular matrix components induced by unsatisfactory T-cells infiltration and poor tumor penetration of antibodies make it challenging to realize efficient tumor immunotherapy. Herein, a peptide-based bispecific nanoblocker (BNB) strategy is reported for in situ construction of CXCR4/PD-L1 targeted nanoclusters on the surface of tumor cells that are capable of boosting T-cells infiltration through CXCR4 blockage and enhancing T-cells activation by PD-L1 occupancy, ultimately realizing high-performance tumor immunotherapy. Briefly, the BNB strategy selectively recognizes and bonds CXCR4/PD-L1 with deep tumor penetration, which rapidly self-assembles into nanoclusters on the surface of tumor cells. Compared to the traditional bispecific antibody, BNB exhibits an intriguing metabolic behavior, that is, the elimination half-life (t1/2 ) of BNB in the tumor is 69.3 h which is ≈50 times longer than that in the plasma (1.4 h). The higher tumor accumulation and rapid systemic clearance overcome potential systemic side effects. Moreover, the solid tumor stress generated by excessive extracellular matrix components is substantially reduced to 44%, which promotes T-cells infiltration and activation for immunotherapy efficacy. Finally, these findings substantially strengthen and extend clinical applications of PD-1/PD-L1 immunotherapy.

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.

Nano Proteolysis Targeting Chimeras (PROTACs) with Anti-Hook Effect for Tumor Therapy

Proteolysis targeting chimera (PROTAC) is an emerging pharmacological modality with innovated post-translational protein degradation capabilities. However, off-target induced unintended tissue effects and intrinsic "hook effect" hinder PROTAC biotechnology to be maturely developed. Herein, an intracellular fabricated nano proteolysis targeting chimeras (Nano-PROTACs) modality with a center-spoke degradation network for achieving efficient dose-dependent protein degradation in tumor is reported. The PROTAC precursors are triggered by higher GSH concentrations inside tumor cells, which subsequently in situ self-assemble into Nano-PROTACs through intermolecular hydrogen bond interactions. The fibrous Nano-PROTACs can form effective polynary complexes and E3 ligases degradation network with multi-binding sites, achieving dose-dependent protein degradation with "anti-hook effect". The generality and efficacy of Nano-PROTACs are validated by degrading variable protein of interest (POI) such as epidermal growth factor receptor (EGFR) and androgen receptor (AR) in a wide-range dose-dependent manner with a 95 % degradation rate and long-lasting potency up to 72 h in vitro. Significantly, Nano-PROTACs achieve in vivo dose-dependent protein degradation up to 79 % and tumor growth inhibition in A549 and LNCap xenograft mice models, respectively. Taking advantages of in situ self-assembly strategy, the Nano-PROTACs provide a generalizable platform to promote precise clinical translational application of PROTAC.

Structure and dynamics of endogenous protein complexes in human heart tissue captured by native nanoproteomics

Protein complexes are highly dynamic entities that display substantial diversity in their assembly, post-translational modifications, and non-covalent interactions, allowing them to play critical roles in various biological processes. The heterogeneity, dynamic nature, and low abundance of protein complexes in their native states present tremendous challenges to study using conventional structural biology techniques. Here we develop a "native nanoproteomics" strategy for the native enrichment and subsequent native top-down mass spectrometry (nTDMS) of low-abundance protein complexes. Specifically, we demonstrate the first comprehensive characterization of the structure and dynamics of cardiac troponin (cTn) complexes directly from human heart tissue. The endogenous cTn complex is effectively enriched and purified using peptide-functionalized superparamagnetic nanoparticles under non-denaturing conditions to enable the isotopic resolution of cTn complexes, revealing their complex structure and assembly. Moreover, nTDMS elucidates the stoichiometry and composition of the heterotrimeric cTn complex, localizes Ca2+ binding domains (II-IV), defines cTn-Ca2+ binding dynamics, and provides high-resolution mapping of the proteoform landscape. This native nanoproteomics strategy opens a new paradigm for structural characterization of low-abundance native protein complexes.

Structure and dynamics of endogenous protein complexes in human heart tissue captured by native nanoproteomics

Protein complexes are highly dynamic entities that display substantial diversity in their assembly, post-translational modifications, and non-covalent interactions, allowing them to play critical roles in various biological processes. The heterogeneity, dynamic nature, and low abundance of protein complexes in their native states present tremendous challenges to study using conventional structural biology techniques. Here we develop a "native nanoproteomics" strategy for the native enrichment and subsequent native top-down mass spectrometry (nTDMS) of low-abundance protein complexes. Specifically, we demonstrate the first comprehensive characterization of the structure and dynamics of cardiac troponin (cTn) complexes directly from human heart tissue. The endogenous cTn complex is effectively enriched and purified using peptide-functionalized superparamagnetic nanoparticles under non-denaturing conditions to enable the isotopic resolution of cTn complexes, revealing their complex structure and assembly. Moreover, nTDMS elucidates the stoichiometry and composition of the heterotrimeric cTn complex, localizes Ca2+ binding domains (II-IV), defines cTn-Ca2+ binding dynamics, and provides high-resolution mapping of the proteoform landscape. This native nanoproteomics strategy opens a new paradigm for structural characterization of low-abundance native protein complexes.

A bispecific glycopeptide spatiotemporally regulates tumor microenvironment for inhibiting bladder cancer recurrence

Up to 75% of bladder cancer patients suffer from recurrence due to postoperative tumor implantation. However, clinically used Bacillus Calmette-Guerin (BCG) treatment failed to inhibit the recurrence. Here, we report a bispecific glycopeptide (bsGP) that simultaneously targets CD206 on tumor-associated macrophages (TAMs) and CXCR4 on tumor cells. bsGP repolarizes protumoral M2-like TAMs to antitumor M1-like that mediated cytotoxicity and T cell recruitment. Meanwhile, bsGP is cleaved by the MMP-2 enzyme to form nanostructure for the long-term inhibition of CXCR4 downstream signaling, resulting in reduced tumor metastasis and promoted T cell infiltration. In orthotopic bladder tumor models, bsGP reduced the postoperative recurrence rate to 22%. In parallel, the recurrence rates of 89 and 78% were treated by doxycycline and BCG used in clinic, respectively. Mechanistic studies reveal that bsGP reduces the matrix microenvironment barrier, increasing the spatially redirected CD8⁺ T cells to tumor cells. We envision that bis-targeting CD206 and CXCR4 may pave the way to inhibit tumor metastasis and recurrence.

A Lysosome-Targeting Self-Condensation Prodrug-Nanoplatform System for Addressing Drug Resistance of Cancer

Lysosome-targeting self-assembling prodrugs had emerged as an attractive approach to overcome the acquisition of resistance to chemotherapeutics by inhibiting lysosomal sequestration. Taking advantage of lysosomal acidification induced intracellular hydrolytic condensation, we developed a lysosomal-targeting self-condensation prodrug-nanoplatform (LTSPN) system for overcoming lysosome-mediated drug resistance. Briefly, the designed hydroxycamptothecine (HCPT)-silane conjugates self-assembled into silane-based nanoparticles, which were taken up into lysosomes by tumor cells. Subsequently, the integrity of the lysosomal membrane was destructed because of the acid-triggered release of alcohol, wherein the nanoparticles self-condensed into silicon particles outside the lysosome through intracellular hydrolytic condensation. Significantly, the LTSPN system reduced the half-maximal inhibitory concentration (IC₅₀) of HCPT by approximately 4 times. Furthermore, the LTSPN system realized improved control of large established tumors and reduced regrowth of residual tumors in several drug-resistant tumor models. Our findings suggested that target destructing the integrity of the lysosomal membrane may improve the therapeutic effects of chemotherapeutics, providing a potent treatment strategy for malignancies.

In Situ Constructed Nano-Drug Depots through Intracellular Hydrolytic Condensation for Chemotherapy of Bladder Cancer

Intravesical administration of first-line drugs has shown failure in the treatment of bladder cancer owing to the poor tumor retention time of chemotherapeutics. Herein, we report an intracellular hydrolytic condensation (IHC) system to construct long-term retentive nano-drug depots in situ, wherein sustained drug release results in highly efficient suppression of bladder cancer. Briefly, the designed doxorubicin (Dox)-silane conjugates self-assemble into silane-based prodrug nanoparticles, which condense into silicon particle-based nano-drug depots inside tumor cells. Significantly, we demonstrate that the IHC system possesses highly potent antitumor efficacy, which leads to the regression and eradication of large established tumors and simultaneously extends the overall survival of air pouch bladder cancer mice compared with that of mice treated with Dox. The concept of intracellular hydrolytic condensation can be extended via conjugating other chemotherapeutic drugs, which may facilitate rational design of novel nanomedicines for augmentation of chemotherapy.

In Situ Self-Assembly of Bispecific Peptide for Cancer Immunotherapy

Precise and effective manipulation of protein functions still faces tremendous challenges. Herein we report a programmable peptide molecule, consisted of targeting and self-assembly modules, that enables specific and highly efficient assembly governed by targeting receptor proteins. Upon binding to the cell membrane receptor, peptide conformation is somewhat stabilized along with decreased self-assembly activation energy, promoting peptide-protein complex oligomerization. We first design a GNNQQNY-RGD peptide (G7-RGD) to recognize integrin α_V β₃ receptor for proof-of-concept study. In the presence of α_V β₃ protein, the critical assembly concentration of free G7-RGD decreases from 525 to 33 μM and the resultant G7-RGD cluster drives integrin receptor oligomerization. Finally, a bispecific assembling peptide antiCD3-G7-RGD is rationally designed for cancer immunotherapy, which validates CD3 oligomerization and concomitant T cell activation, leading to T cell-mediated cancer cell cytolysis.

Targeted in situ self-assembly augments peptide drug conjugate cell-entry efficiency

Peptide drug conjugate (PDC) has emerged as one of the new generations of targeted therapeutics for cancer, which owns the advantages of improved drug targetability and reduced adverse effects compared with traditional chemotherapy. However, the poor permeability of PDC drugs regarding tumor cells is an urgent problem to be solved. Herein, we design a PDC drug molecule, which is composed of three modules: targeting motif (RGD target), assembly motif (GNNNQNY) and cytotoxic payload (CPT molecule). This PDC in situ forms nanoclusters upon binding cellular receptor, resulting in improved PDC cell-entry efficiency and treatment efficacy. In addition, the PDC shows increased therapeutic efficacy and raises the maximum tolerance dose of the drug in breast and bladder xenografted mice models. This strategy leverages the assembly principle to promote penetration of peptide molecules into cells and increase intracellular drug bioavailability, which is of great significance for the development of PDC drugs in the future.

Click Reaction-Assisted Peptide Immune Checkpoint Blockade for Solid Tumor Treatment

One of the major challenges of immune checkpoint blockade (ICB) is the poor penetration of antibody for solid tumor treatment. Herein, peptides with deeper penetration capability are used to develop a click reaction-assisted peptide immune checkpoint blockade (CRICB) strategy that could in situ construct assemblies, enabling enhanced accumulation and prolonged PD-L1 occupancy, ultimately realizing high-performance tumor inhibition. First, the free DBCO-modified targeting peptide (TP) efficiently recognizes and binds PD-L1 in a deep solid tumor. Upon a reagent-free click reaction with a subsequently introduced azide-tethered assembled peptide (AP), the click reaction results in spontaneous self-aggregation in situ with enhanced accumulation and prolonged occupancy. In addition, the penetration of TP-AP (121.2 ± 15.5 μm) is significantly enhanced compared with that of an antibody (19.9 ± 5.6 μm) in a solid tumor tissue. More importantly, significant immunotherapy effects and negligible side effects are observed in 4T1 and CT26 tumor-bearing mice models treated with TP-AP, suggesting the high-performance tumor inhibition attributed to the CRICB strategy. In summary, this CRICB strategy manifest the preferable effects of immune checkpoint blockade, thereby extending the biomedical application of assembling peptides.

A Near-Infrared Peptide Probe with Tumor-Specific Excretion-Retarded Effect for Image-Guided Surgery of Renal Cell Carcinoma

Image-guided surgery plays a crucial role in realizing complete tumor removal, reducing postoperative recurrence and increasing patient survival. However, imaging of tumor lesion in the typical metabolic organs, e.g., kidney and liver, still has great challenges due to the intrinsic nonspecific accumulation of imaging probes in those organs. Herein, we report an in situ self-assembled near-infrared (NIR) peptide probe with tumor-specific excretion-retarded (TER) effect in tumor lesions, enabling high-performance imaging of human renal cell carcinoma (RCC) and achieving complete tumor removal, ultimately reducing postoperative recurrence. The NIR peptide probe first specifically recognizes α_vβ₃ integrin overexpressed in renal cancer cells, then is cleaved by MMP-2/9, which is up-regulated in the tumor microenvironment. The probe residue spontaneously self-assembles into nanofibers that exhibit an excretion-retarded effect in the kidney, which contributes to a high signal-to-noise (S/N) ratio in orthotopic RCC mice. Intriguingly, the TER effect also enables precisely identifying eye-invisible tiny lesions (<1 mm), which contributes to complete tumor removal and significantly reduces the postoperative recurrence compared with traditional surgery. Finally, the TER strategy is successfully employed in high-performance identification of human RCC in an ex vivo kidney perfusion model. Taken together, this NIR peptide probe based on the TER strategy is a promising method for detecting tumors in metabolic organs in diverse biomedical applications.

[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.

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.

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.

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.

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.

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.