In vitro determination of the contraceptive spermicidal activity of essential oil of Trachyspermum ammi (L.) Sprague ex Turrill fruits

This study was conducted to determine the spermicidal and contraceptive efficacy of essential oil of Trachyspermum ammi on human sperm in vitro. Chemical compositions of the oil were analyzed by GC-MS. Nearly 30 compounds representing 91.39% of the total oil were identified. The minimum effective dose (MED) of essential oil of T. ammi that induced instant immobilization of human spermatozoa in vitro was 125 μg/mL. The motility was also irreversible. All of the human sperms were found to be non viable within 10 min at this concentration. The activity of acrosomal enzyme was reduced and a significant releases of 5'-nucleotidase into the surrounding medium was noted after treatment with MED concentration of essential oil, indicating the plasma membrane degradation of the sperm. The maximum number of human sperm failed to decondense when treated with MED concentration of essential oil. The morphological deformities of sperm plasma membrane were evidenced by SEM, which showed vaculation, detachment of heads and tail coiling. The present research indicates that essential oil of T. ammi possesses appreciable spermicidal potential, which may be explored as an effective constituent of vaginal contraceptive.     

Proteome analysis of Thermococcus onnurineus NA1 reveals the expression of hydrogen gene cluster under carboxydotrophic growth

Thermococcus onnurineus NA1 is a typical sulfur-reducing hyperthermophilic archaeon. Genome sequence analysis has shown that T. onnurineus NA1 retains the metabolic pathways necessary not only for organotrophic, but also for carboxydotrophic, growth. T. onnurineus NA1 carboxydotrophic growth may result in hydrogen production, as this archaeon produces hydrogen during oxidizing formate. In this study, we profiled the proteome of T. onnurineus NA1 cultured under carboxydotrophic conditions using CO as an electron donor by the SDS-PAGE/LC-MS/MS method. A total of 1395 proteins were identified by two independent proteomic analyses, which corresponds to ~71% of the total predicted open reading frames. To our knowledge, this level of identification coverage exceeds those of other global proteome profiling studies in Archaea. Furthermore, the biological functions of the identified proteins were predicted and cognate enzymes were mapped to the appropriate metabolic pathways. More than 90% of the genes belonging to hydrogenase gene clusters such as Mbx, Sulf-I, Mbh, Hyg4-I, Hyg4-II, and Hyf4-III were expressed during CO culture. This means that hydrogenases induced under carboxydotrophic conditions surpass those induced under an organotrophic condition (yeast extract-peptone-sulfur). Our data suggest that hydrogen production is caused by the expression and functional assembly of T. onnurineus NA1 hydrogenase genes during culture in the presence of CO.     

A soluble acetylcholinesterase provides chemical defense against xenobiotics in the pinewood nematode

The pinewood nematode genome encodes at least three distinct acetylcholinesterases (AChEs). To understand physiological roles of the three pinewood nematode AChEs (BxACE-1, BxACE-2, and BxACE-3), BxACE-3 in particular, their tissue distribution and inhibition profiles were investigated. Immunohistochemistry revealed that BxACE-1 and BxACE-2 were distributed in neuronal tissues. In contrast, BxACE-3 was detected from some specific tissues and extracted without the aid of detergent, suggesting its soluble nature unlike BxACE-1 and BxACE-2. When present together, BxAChE3 significantly reduced the inhibition of BxACE-1 and BxACE-2 by cholinesterase inhibitors. Knockdown of BxACE-3 by RNA interference significantly increased the toxicity of three nematicidal compounds, supporting the protective role of BxACE-3 against chemicals. In summary, BxACE-3 appears to have a non-neuronal function of chemical defense whereas both BxACE-1 and BxACE-2 have classical neuronal function of synaptic transmission.     

Embryonic and induced pluripotent stem cell staining and sorting with the live-cell fluorescence imaging probe CDy1

Detecting and isolating specific types of cells is crucial to understanding a variety of biological processes, including development, aging, regeneration and pathogenesis; this understanding, in turn, allows the use of cells for therapeutic purposes, for which stem cells have emerged recently as invaluable materials. The current methods of isolation and characterization of stem cells depend on cell morphology in culture or on immunostaining of specific markers. These methods are, however, time consuming and involve the use of antibodies that may often make the cells unsuitable for further study. We recently developed a fluorescent small molecule named CDy1 (compound of designation yellow 1) that selectively stains live embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). This protocol describes detailed procedures for staining ESC and iPSC in live conditions and for fluorescence-activated cell sorting (FACS) of ESC using CDy1. Cell staining, image acquisition and FACS can be done within 6 h.     

The integrated HIV-1 provirus in patient sperm chromosome and its transfer into the early embryo by fertilization

Complete understanding of the route of HIV-1 transmission is an important prerequisite for curbing the HIV/AIDS pandemic. So far, the known routes of HIV-1 transmission include sexual contact, needle sharing, puncture, transfusion and mother-to-child transmission. Whether HIV can be vertically transmitted from human sperm to embryo by fertilization is largely undetermined. Direct research on embryo derived from infected human sperm and healthy human ova have been difficult because of ethical issues and problems in the collection of ova. However, the use of inter-specific in vitro fertilization (IVF) between human sperm and hamster ova can avoid both of these problems. Combined with molecular, cytogenetical and immunological techniques such as the preparation of human sperm chromosomes, fluorescent in situ hybridization (FISH), and immunofluorescence assay (IFA), this study mainly explored whether any integrated HIV provirus were present in the chromosomes of infected patients' sperm, and whether that provirus could be transferred into early embryos by fertilization and maintain its function of replication and expression. Evidence showed that HIV-1 nucleic acid was present in the spermatozoa of HIV/AIDS patients, that HIV-1 provirus is present on the patient sperm chromosome, that the integrated provirus could be transferred into early embryo chromosomally integrated by fertilization, and that it could replicate alongside the embryonic genome and subsequently express its protein in the embryo. These findings indicate the possibility of vertical transmission of HIV-1 from the sperm genome to the embryonic genome by fertilization. This study also offers a platform for the research into this new mode of transmission for other viruses, especially sexually transmitted viruses.     

Transmission dynamics of methicillin-resistant Staphylococcus aureus in a medical intensive care unit in India

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is a global pathogen and an important but seldom investigated cause of morbidity and mortality in lower and middle-income countries where it can place a major burden on limited resources. Quantifying nosocomial transmission in resource-poor settings is difficult because molecular typing methods are prohibitively expensive. Mechanistic statistical models can overcome this problem with minimal cost. We analyse the transmission dynamics of MRSA in a hospital in south India using one such approach and provide conservative estimates of the organism''s economic burden.

Methods and Findings

Fifty months of MRSA infection data were collected retrospectively from a Medical Intensive Care Unit (MICU) in a tertiary hospital in Vellore, south India. Data were analysed using a previously described structured hidden Markov model.Seventy-two patients developed MRSA infections and, of these, 49 (68%) died in the MICU. We estimated that 4.2% (95%CI 1.0, 19.0) of patients were MRSA-positive when admitted, that there were 0.39 MRSA infections per colonized patient month (0.06, 0.73), and that the ward-level reproduction number for MRSA was 0.42 (0.08, 2.04). Anti-MRSA antibiotic treatment costs alone averaged $124/patient, over three times the monthly income of more than 40% of the Indian population.

Conclusions

Our analysis of routine data provides the first estimate of the nosocomial transmission potential of MRSA in India. The high levels of transmission estimated underline the need for cost-effective interventions to reduce MRSA transmission in hospital settings in low and middle income countries.     

Introgression of chromosome 3Ns from Psathyrostachys huashanica into wheat specifying resistance to stripe rust

Wheat stripe rust is a destructive disease in the cool and humid wheat-growing areas of the world. Finding diverse sources of stripe rust resistance is critical for increasing genetic diversity of resistance for wheat breeding programs. Stripe rust resistance was identified in the alien species Psathyrostachys huashanica, and a wheat-P. huashanica amphiploid line (PHW-SA) with stripe rust resistance was reported previously. In this study, a P. huashanica 3Ns monosomic addition line (PW11) with superior resistance to stripe rust was developed, which was derived from the cross between PHW-SA and wheat J-11. We evaluated the alien introgressions PW11-2, PW11-5 and PW11-8 which were derived from line PW11 for reaction to new Pst race CYR32, and used molecular and cytogenetic tools to characterize these lines. The introgressions were remarkably resistant to CYR32, suggesting that the resistance to stripe rust of the introgressions thus was controlled by gene(s) located on P. huashanica chromosome 3Ns. All derived lines were cytologically stable in term of meiotic chromosome behavior. Two 3Ns chromosomes of P. huashanica were detected in the disomic addition line PW11-2. Chromosomes 1B of substitution line PW11-5 had been replaced by a pair of P. huashanica 3Ns chromosomes. In PW11-8, a small terminal segment from P. huashanica chromosome arm 3NsS was translocated to the terminal region of wheat chromosomes 3BL. Thus, this translocated chromosome is designated T3BL-3NsS. These conclusions were further confirmed by SSR analyses. Two 3Ns-specific markers Xgwm181 and Xgwm161 will be useful to rapidly identify and trace the translocated fragments. These introgressions, which had significant characteristics of resistance to stripe rust, could be utilized as novel germplasms for wheat breeding.     

A comprehensive peptidome profiling technology for the identification of early detection biomarkers for lung adenocarcinoma

The mass spectrometry-based peptidomics approaches have proven its usefulness in several areas such as the discovery of physiologically active peptides or biomarker candidates derived from various biological fluids including blood and cerebrospinal fluid. However, to identify biomarkers that are reproducible and clinically applicable, development of a novel technology, which enables rapid, sensitive, and quantitative analysis using hundreds of clinical specimens, has been eagerly awaited. Here we report an integrative peptidomic approach for identification of lung cancer-specific serum peptide biomarkers. It is based on the one-step effective enrichment of peptidome fractions (molecular weight of 1,000-5,000) with size exclusion chromatography in combination with the precise label-free quantification analysis of nano-LC/MS/MS data set using Expressionist proteome server platform. We applied this method to 92 serum samples well-managed with our SOP (standard operating procedure) (30 healthy controls and 62 lung adenocarcinoma patients), and quantitatively assessed the detected 3,537 peptide signals. Among them, 118 peptides showed significantly altered serum levels between the control and lung cancer groups (p<0.01 and fold change >5.0). Subsequently we identified peptide sequences by MS/MS analysis and further assessed the reproducibility of Expressionist-based quantification results and their diagnostic powers by MRM-based relative-quantification analysis for 96 independently prepared serum samples and found that APOA4 273-283, FIBA 5-16, and LBN 306-313 should be clinically useful biomarkers for both early detection and tumor staging of lung cancer. Our peptidome profiling technology can provide simple, high-throughput, and reliable quantification of a large number of clinical samples, which is applicable for diverse peptidome-targeting biomarker discoveries using any types of biological specimens.     

Direct observation of defects and increased ion permeability of a membrane induced by structurally disordered Cu/Zn-superoxide dismutase aggregates

Interactions between protein aggregates and a cellular membrane have been strongly implicated in many protein conformational diseases. However, such interactions for the case of Cu/Zn superoxide dismutase (SOD1) protein, which is related to fatal neurodegenerative disorder amyotrophic lateral sclerosis (ALS), have not been explored yet. For the first time, we report the direct observation of defect formation and increased ion permeability of a membrane induced by SOD1 aggregates using a supported lipid bilayer and membrane patches of human embryonic kidney cells as model membranes. We observed that aggregated SOD1 significantly induced the formation of defects within lipid membranes and caused the perturbation of membrane permeability, based on surface plasmon resonance spectroscopy, atomic force microscopy and electrophysiology. In the case of apo SOD1 with an unfolded structure, we found that it bound to the lipid membrane surface and slightly perturbed membrane permeability, compared to other folded proteins (holo SOD1 and bovine serum albumin). The changes in membrane integrity and permeability were found to be strongly dependent on the type of proteins and the amount of aggregates present. We expect that the findings presented herein will advance our understanding of the pathway by which structurally disordered SOD1 aggregates exert toxicity in vivo.