AKT1 polymorphisms are associated with tuberculosis in the Chinese population

AKT1, a serine/threonine kinase, plays a critical role in the controlling of intracellular growth of Mycobacterium tuberculosis. In this study, we investigated whether polymorphisms in AKT1 affect susceptibility to tuberculosis (TB). Two single nucleotide polymorphisms of AKT1, IVS3+18C>T and +726G>A were genotyped in Chinese patients with pulmonary TB by polymerase chain reaction-restriction fragment length polymorphism. Patients with pulmonary TB had significantly lower IVS3+18 C/C genotype and higher C/T genotype compared with age-, gender- and ethnically matched controls (P < 0.05). The T-A haplotype frequency was significantly higher in patients than in controls (P < 0.05). In conclusion, our result indicates that AKT1 polymorphisms are associated with susceptibility to pulmonary TB.

Experimental and Numerical Study of Improving Heavy Oil Recovery by Alkaline Flooding in Sandpacks

Abstract

Chemical flooding has great potential for enhancing heavy oil recovery, especially for reservoirs where thermal methods are not feasible. It has been shown that the formation of emulsions during chemical flooding can effectively improve sweep efficiency and, consequently, increase heavy oil recovery. The mechanism of flow of oil-in-water (O/W) emulsion in porous media has been extensively studied and simulated using the filtration theory. Few studies have been done for the modelling of water-in-oil (W/O) emulsion flow in heavy oil reservoirs. This study experimentally investigated the effective viscosity of W/O emulsion in porous media. Alkaline flooding tests were performed in channelled sandpacks to demonstrate the effectiveness of sweep efficiency improvement by the in-situ produced W/O emulsions. High tertiary oil recoveries were obtained for all these tests. The alkaline flooding process was simulated by including the observed flow behaviour of extra resistance to water phase flow caused by the formation of W/O emulsions, as well as the adsorption of chemicals, interfacial tension reduction, and in-situ generation of W/O emulsions. These laboratory results and the developed simulation technique are proposed as an improvement to the simulation and design of the field-scale projects of chemical flooding for heavy oil recovery.

Introduction

Many heavy oil reservoirs in Western Canada are not suitable for steam injection techniques due to thin pay thickness. Both field and laboratory results demonstrate that waterflooding of heavy oil reservoirs can only achieve a very low oil recovery. The main causes for the poor sweep efficiency of waterflooding for these heavy oil reservoirs are very adverse mobility ratio, natural area and vertical reservoir heterogeneity and heterogeneity induced by primary production(1,2). Therefore, improving mobility ratio and blocking water flow through channels are essential for improving heavy oil recovery. The in-situ formation of emulsions during alkaline flooding has been recognized as one of the efficient methods to improve sweep efficiency for heavy oil recovery(3,4,5).

The effectiveness of alkaline flooding for acidic crudes was recognized as early as in the 1920s(6). Jennings et al.(3) proposed the mechanism of emulsification and entrapment for alkaline flooding. They carried out caustic flooding tests using a heavy oil. Their results showed that the in-situ produced O/W emulsions tended to plug water fingering and channels, resulting in improved sweep efficiency. Johnson(7) summarized possible mechanisms of alkaline flooding to improve oil recovery: dispersion and entrainment, wettability reversal, and emulsification and entrapment. The formation of W/O emulsions was also observed as a mechanism of improving oil recovery(8,9).

The Presence of Hepatitis B Surface Antigen in the Ova of Pregnant Women and Its Relationship with Intra-Uterine Infection by Hepatitis B Virus

Vertical transmission of hepatitis B virus (HBV) has been proposed to play an important role in mother-to-child transmission, although the extent to which vertical transmission via oocytes contributes to neonatal HBV infection remains unknown. Ovarian biopsies were collected during caesarean sections in 68 clinically asymptomatic pregnant women who were carriers of HBV. The presence of hepatitis B surface antigen (HBsAg) in the ova of pregnant women was determined by immunohistochemistry. Serum markers of HBV infection in pregnant women and their neonates were analysed. It was found that, of 68 women, the ova were positive for HBsAg in only one woman and her neonate was negative for any serum HBV markers 3 days after birth. Of 68 neonates, one was positive for serum HBV markers 3 days after birth and his mother's ova were negative for HBsAg. These findings indicate that vertical transmission via oocytes may not be the major route of HBV intra-uterine infection.

Brushing effects on the growth and mechanical properties of Corispermum mongolicum vary with water regime

High water availability and mechanical stress can induce opposite responses in plants. In arid areas of Northern China the occurrence of high wind and high water availability tend to be negatively correlated. Since turgor pressure is a determinant of the mechanical stability of annuals, it is hypothesised that the effects of mechanical perturbation (MP) on annuals may depend on soil water availability. To test this proposal, we conducted an experiment in which a pioneering annual Corispermum mongolicum was subjected to two levels of MP and water supply, and then determined its growth and mechanical traits. Brushing had no effect on plant height and total biomass, but stimulated leaf and branch production. Water supply affected plant height, basal diameter, total biomass and stem rigidity, but not leaf and branch number, root/shoot ratio or flexibility. With high water availability, brushing stimulated the production of stiffer stems (thicker and with a higher Young's modulus) and more roots relative to shoot mass, but with low water availability MP induced the opposite response. This shows that both the degree and direction of plant responses to MP depend on the presence of other factors. We discuss how the interactive effects of MP and water availability on growth and mechanical properties may help C. mongolicum to establish in windy and arid environments.

Phase I study of chidamide (CS055/HBI-8000), a novel histone deacetylase inhibitor, in patients with advanced solid tumors and lymphomas

3529

Background: Chidamide (CS055/HBI-8000) is a new benzamide type of histone deacetylase (HDAC) inhibitor with low nanomolar activity against HDAC1, 2, 3 and 10. This Phase I study evaluated the safety and tolerability of chidamide in patients (pts) with advanced solid tumors and lymphomas. Methods: 31 pts with refractory or relapsed advanced solid tumors (22) and lymphomas (9) were enrolled in this study. Escalating doses of 5, 10, 17.5, 25, 32.5 and 50 mg Chidamide (each with 3 to 7 pts) were administered orally either twice or three times per week for 4 consecutive weeks every 6 weeks. Results: No dose limiting toxicities (DLTs) were identified in the 2 x per week cohorts (22 pts) up to 50 mg; G2 and G3 hematological toxicities (leukopenia/neutropenia and thrombocytopenia) were observed at 50 mg. DLTs were reported as G3 diarrhea or vomiting in 2 pts in the 3 x per week cohort at 50 mg. Common adverse events were G1/G2, fatigue (n = 11), thrombocytopenia (n = 9), anorexia (n = 8), nausea/vomiting (n = 7), leukopenia/neutropenia (n = 6), hypochromia (n = 6), and diarrhea (n = 5). No cystitis, pericarditis, pericardial effusion or prolonged QTc intervals were observed. Single dose PK analysis in pts with 25, 32.5 and 50 mg revealed T1/2 of 16.8–18.3 h, Tmax of 1–2 h in most cases, and a dose-related increase in Cmax and AUC. Multiple dose PK analysis in pts with 32.5 mg 3 x per week suggested drug accumulation with this regimen. Significant induction of histone (H3) acetylation was observed in peripheral white blood cells, which lasted for 2–3 days in most pts after single dosing. 25 pts with total treatment cycles of 49 (range 1–6) were evaluable for efficacy. 4 pts with T-cell lymphomas (4/5 evaluable) and 1 pt with submandibular adenoid cystic carcinoma achieved PR, and 11 pts (2 B-cell lymphomas and 9 solid tumors) experienced SD. Conclusions: Chidamide was well-tolerated in pts with advanced solid tumors and lymphomas in the tested regimens. In addition, the compound exhibited a relatively long half-life, a long-lasting biomarker response and encouraging antitumor activity at well-tolerated doses. The overall phase I results recommend the 2 x per week regimen for phase II studies.

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Clonal integration supports the expansion from terrestrial to aquatic environments of the amphibious stoloniferous herb Alternanthera philoxeroides

Effects of clonal integration on land plants have been extensively studied, but little is known about the role in amphibious plants that expand from terrestrial to aquatic conditions. We simulated expansion from terrestrial to aquatic habitats in the amphibious stoloniferous alien invasive alligator weed (Alternanthera philoxeroides) by growing basal ramets of clonal fragments in soils connected (allowing integration) or disconnected (preventing integration) to the apical ramets of the same fragments submerged in water to a depth of 0, 5, 10 or 15 cm. Clonal integration significantly increased growth and clonal reproduction of the apical ramets, but decreased both of these characteristics in basal ramets. Consequently, integration did not affect the performance of whole clonal fragments. We propose that alligator weed possesses a double-edged mechanism during population expansion: apical ramets in aquatic habitats can increase growth through connected basal parts in terrestrial habitats; however, once stolon connections with apical ramets are lost by external disturbance, the basal ramets in terrestrial habitats increase stolon and ramet production for rapid spreading. This may contribute greatly to the invasiveness of alligator weed and also make it very adaptable to habitats with heavy disturbance and/or highly heterogeneous resource supply.

Advanced malignant pleural or peritoneal effusion in patients treated with recombinant adenovirus p53 injection plus cisplatin

The aim of this study was to evaluate the efficacy of recombinant adenovirus p53 agent (rAd-p53) injection combined with cisplatin (CDDP) for the treatment of malignant pleural or peritoneal effusion. After puncture drainage, patients in the treatment group (n = 27) received intracavitary administration of rAd-p53 (2 x 10(12) virus particles) once a week for 4 weeks. At 48 h after each rAd-p53 injection, patients were given intracavitary administration of cisplatin 60 mg/m(2). This administration procedure continued once a week for 4 weeks. The control group (n = 21) received the same intracavitary therapy as the treatment group but without rAd-p53 therapy. Efficacy was evaluated by clinical observations, computed tomography, tumour markers, Karnofsky score and short-term follow-up. The total effective rates for the treatment group (63.0%) were significantly higher than for the control group (42.9%), suggesting that the treatment group benefited over the control group. In conclusion, rAd-p53 therapy is a safe and effective treatment for advanced malignant pleural or peritoneal effusion.

Automating fruit fly Drosophila embryo injection for high throughput transgenic studies

To decipher and manipulate the 14 000 identified Drosophila genes, there is a need to inject a large number of embryos with transgenes. We have developed an automated instrument for high throughput injection of Drosophila embryos. It was built on an inverted microscope, equipped with a motorized xy stage, autofocus, a charge coupled device camera, and an injection needle mounted on a high speed vertical stage. A novel, micromachined embryo alignment device was developed to facilitate the arrangement of a large number of eggs. The control system included intelligent and dynamic imaging and analysis software and an embryo injection algorithm imitating a human operator. Once the injection needle and embryo slide are loaded, the software automatically images and characterizes each embryo and subsequently injects DNA into all suitable embryos. The ability to program needle flushing and monitor needle status after each injection ensures reliable delivery of biomaterials. Using this instrument, we performed a set of transformation injection experiments. The robot achieved injection speeds and transformation efficiencies comparable to those of a skilled human injector. Because it can be programed to allow injection at various locations in the embryo, such as the anterior pole or along the dorsal or ventral axes, this system is also suitable for injection of general biochemicals, including drugs and RNAi.

Structural basis of natural ligand binding and activation of the Class II G-protein-coupled secretin receptor

The secretin receptor is prototypic of Class II GPCRs (G-protein-coupled receptors), based on its structural and functional characteristics and those of its natural agonist ligand. Secretin represents a linear 27-residue peptide with diffuse pharmacophoric domain. The secretin receptor includes the typical signature sequences for this receptor family within its predicted transmembrane segments and the highly conserved six cysteine residues contributing to three intradomain disulfide bonds within its long N-terminus. This domain is critical for secretin binding based on receptor mutagenesis and photoaffinity labelling studies. Full agonist analogues of secretin incorporating a photolabile moiety at various positions throughout the pharmacophore covalently label residues within this region, while only N-terminal probes have labelled the core helical bundle domain. Combining insights coming from receptor structural studies, peptide structure-activity relationship considerations, photoaffinity labelling, and application of fluorescence techniques has resulted in the development of a working model of the secretin-receptor complex. This supports the initial docking of the peptide agonist within a cleft in the receptor N-terminus, providing the opportunity for an endogenous sequence within that domain to interact with the core of the receptor. This interaction is believed to be key in the molecular basis of conformational change associated with activation of this receptor. The site of action of this endogenous agonist could also provide a possible target for small molecule agonists to act.