In vivo evolutionary engineering for ethanol-tolerance of Saccharomyces cerevisiae haploid cells triggers diploidization.

Microbial ethanol production is an important alternative energy resource to replace fossil fuels, but at high level, this product is highly toxic, which hampers its efficient production. Towards increasing ethanol-tolerance of Saccharomyces cerevisiae, the so far best industrial ethanol-producer, we evaluated an in vivo evolutionary engineering strategy based on batch selection under both constant (5%, v v) and gradually increasing (5-11.4%, v v) ethanol concentrations.

Chromosomal abnormalities in infertile men referred to iran blood transfusion organization research center.

Introduction: The prevalence of somatic chromosomal abnormalities in infertile male individuals has been reported to vary in different literatures. The aim of this study was to investigate the frequency of chromosomal aberrations among infertile men referred to the Cytogenetic Laboratory of Iran Blood Transfusion Organization Research Centre (IBTO).

Materials And Methods: Chromosomal analysis was performed on phytohemag-glutinin (PHA)-stimulated peripheral lymphocyte cultures of 1052 infertile men using standard cytogenetic methods.

An Iranian herbal-marine medicine, MS14, ameliorates experimental allergic encephalomyelitis.

Multiple sclerosis is an inflammatory and demyelinating disease of the central nervous system which mainly affects young adults. To overcome wide spectrum troublesome symptoms of multiple sclerosis which affects the quality of life both in patients and their families, new drugs and remedies have been examined and offered. The preclinical beneficial effects of different medicines have mostly been examined in an animal model of multiple sclerosis called experimental allergic encephalomyelitis (EAE).

Novel short peptides isolated from phage display library inhibit vascular endothelial growth factor activity.

Signal transduction through the vascular endothelial growth factor (VEGF)-VEGF receptor (VEGFR) pathway has a pivotal importance in angiogenesis, and has therefore become a prime target in antitumor therapy. In search for peptides antagonizing VEGF binding to its receptors, we screened a random heptamer library displayed on phage for peptides that bind the whole VEGF165 molecule and inhibit VEGF dependent human umbilical vein endothelial cell (HUVEC) proliferation. Two selected peptides with sequences WHLPFKC and WHKPFRF were synthesized.

Stable transmission and transcription of newfoundland ocean pout type III fish antifreeze protein (AFP) gene in transgenic mice and hypothermic storage of transgenic ovary and testis.

Here we describe the generation of transgenic mice carrying type III fish antifreeze protein (AFP) gene and evaluate whether AFP type III protects transgenic mouse ovaries and testes from hypothermic storage. AFPs exist in many different organisms. In fish, AFPs protect the host from freezing at temperatures below the colligative freezing point by adsorbing to the surface of nucleating ice crystals and inhibiting their growth.

Visualization and sensing of intermolecular interactions with two-color fluorescent probes.

We developed a new generic fluorescence sensing technology based on the change of relative intensities between two well-separated emission bands of the novel functional 3-hydroxychromone (3HC) dyes. A greatly enhanced self-calibrating wavelength-ratiometric response is obtained to all major types of non-covalent interactions that can be used in sensing--to polarity, hydrogen bonding ability and to local electrostatic fields. This technology may find a broad range of applications--from homogeneous assays in solutions to microarrays, microfluidic devices, nanosensors and whole cell imaging systems.

Synthesis and characterization of poly(L-lactic acid-co-ethylene oxide-co-aspartic acid) and its interaction with cells.

Multiblock terpolymer of poly(L-lactic acid)/poly(ethylene oxide)/poly(L-aspartic acid), (PLLA/PEO/PAsp) was synthesized by ring opening polymerization of beta -benzyl L-aspartate N-carboxyanhydride, Asp(OBzl)-NCA with alpha-omega -hydroxy terminated triblock PLLA/PEO/PLLA copolymer. The resulting multiblock terpolymer was characterized by several techniques including Fourier transform infrared spectroscopy and differential scanning calorimetry.(1)H nuclear magnetic resonance spectra indicated the molar ratio of PLLA/PEO/PAsp (OBzl) to be 86/10/4.

Stable transmission and expression of the hepatitis B virus total genome in hybrid transgenic mice until F10 generation.

The aim of the present study was the generation of transgenic mice carrying the complete Hepatitis B Virus (HBV) genome and investigation of the presence of Hepatitis B surface antigen (HBsAg) expression through successive generations. Transgenic mice were generated by microinjecting HBV genome into fertilized eggs. Integration and expression of HBsAg in transgenic mice were analyzed by genomic DNA PCR, Southern and slot blots and enzyme-linked immunosorbent assay (ELISA).

The effects of thermal quenching on the excited-state intramolecular proton transfer reaction in 3-hydroxyflavones.

The 3-hydroxyflavone (3HF) and its derivatives are the classical objects in the studies of the mechanisms of excited-state intramolecular proton transfer (ESIPT) reaction due to very frequent observation of two separate bands in fluorescence emission belonging to reactant and reaction product. Those of them possessing electron-donor groups in 4' position find many applications as fluorescence sensors and probes because of their much higher sensitivity of their two-band ratiometric response to interactions with the environment. We report on the strong differences between 3HF and such derivatives in the behavior of their fluorescence spectra as a function of temperature.

The problem of self-calibration of fluorescence signal in microscale sensor systems.

Most recent developments in fluorescent molecular sensor devices are based on "ON-OFF" switching, which is an operation with a single measurable parameter, commonly the quenching of total intensity. In the meantime, with this approach self-calibration on the molecular level is not achievable. This calibration is strongly needed in all kinds of microscale applications, including microarrays, microfluidic systems and living cell imaging.

The effect of equilibration time on survival and development rates of mouse pronuclear-stage embryos vitrified in solid surface (SSV) and convential straws: in vitro and in vivo evaluations.

The objective of this study was to improve the efficiency of cryopreservation of pronuclear-stage (PN) mouse embryos. A novel vitrification technique (solid surface vitrification, SSV) was compared with a convential one in straws both for cryosurvival and obtaining progeny from cryopreserved PN mouse embryos. In the SSV method, 15-20 PN embryos were exposed to vitrification solutions for approximately 20 sec after equilibration, and then they were dropped in 2 microl drops onto a pre-cooled (-150 to -180 degrees C) metal surface.

A triterpene oleanolic acid conjugate with 3-hydroxyflavone derivative as a new membrane probe with two-color ratiometric response.

We report on the synthesis by coupling of a triterpenoid oleanolic acid with 4'-diethylamino-3-hydroxyflavone (FE) to produce an environment-sensitive biomembrane probe with two-band ratiometric response in fluorescence emission. The synthesized compound (probe FOT) was tested in a series of model solvents and demonstrated the response to solvent polarity and intermolecular hydrogen bonding very similar to that of parent probe FE. Meantime when incorporated into lipid bilayer membranes, it showed new features differing in response between lipids of different surface charges as well as between glycerophospholipids and sphingomyelin.

Purification and characterization of a serine alkaline protease from Bacillus clausii GMBAE 42.

An extracellular serine alkaline protease of Bacillus clausii GMBAE 42 was produced in protein-rich medium in shake-flask cultures for 3 days at pH 10.5 and 37 degrees C. Highest alkaline protease activity was observed in the late stationary phase of cell cultivation.

The future of fluorescence sensor arrays.

The rapid progress in sensor and biosensor array technologies needs a general strategy in the design of fluorescence reporters. Such reporters should provide a high density of sensor elements, allow analysis of targets of different affinities, and be internally calibrated, reproducible and have a rapid readout. Several criteria are introduced here for the comparative evaluation of fluorescence-sensing techniques.

The binding of novel two-color fluorescence probe FA to serum albumins of different species.

The novel two-color ratiometric fluorescence probe FA belonging to a class of 3-hydroxychromone dyes was applied for characterization of binding sites in serum albumins obtained from seven species (bovine, dog, horse, human, pig, rabbit and sheep). On strong and highly specific FA binding to the same location in protein structure, the species-dependent differences were observed in positions of absorption maxima, positions of two fluorescence emission bands and the intensity ratios between them. They were analyzed by multiparametric algorithm that allowed a detailed characterization of probe-binding sites and were characterized by very low polarity, high electronic polarizability and different extent of intermolecular hydrogen bonding.

Antibacterial activity of seed proteins of Robinia pseudoacacia.

A low molecular weight cationic peptide was isolated from Robinia pseudoacacia seed and tested in vitro against seven bacteria (Corynebacterium michiganense, Staphylococcus aureus, Bacillus subtilis, Erwinia carotovora subsp. carotovora, Pseudomonas syringae pv syringae, Xanthomonas campestris pv campestris, and Escherichia coli). The peptide inhibited the growth of the tested strains.

Effect of chemically defined culture medium supplemented with beta-mercaptoethanol and amino acids on implantation and development of different stage in vivo- or in vitro-derived mouse embryos.

In vitro culture (IVC) systems are required for many biotechnological and assisted reproductive technologies and the researchers have been modifying in vitro embryo culture conditions to reach the comparable efficiencies provided in vivo. In the present study, the effects of beta-mercaptoethanol (Beta-ME) and amino acids (AA) on the development of mouse embryos obtained in vivo or in vitro at different stages were investigated. Chemically defined potassium simplex optimized medium (KSOM) was used as basic culture medium and six experimental groups were established and by supplementation of Beta-ME and AA into KSOM media.

The role of ADP-ribosylation factor and SAR1 in vesicular trafficking in plants.

Ras-like small GTP binding proteins regulate a wide variety of intracellular signalling and vesicular trafficking pathways in eukaryotic cells including plant cells. They share a common structure that operates as a molecular switch by cycling between active GTP-bound and inactive GDP-bound conformational states. The active GTP-bound state is regulated by guanine nucleotide exchange factors (GEF), which promote the exchange of GDP for GTP.

Exposure to warmer postoperative temperatures reduces hypothermia caused by anaesthesia and significantly increases the implantation rate of transferred embryos in the mouse.

Embryo transfer (ET) is among the key factors determining the overall efficiency of transgenic technology in the mouse. A successful ET depends among other factors on the quality of the transferred embryos, foster mothers and anaesthetic reagents and on the transfer techniques. Anaesthesia-caused deaths and suboptimal ET procedures are factors which reduce the success of transgenic experiments and mouse colony maintenance.

Newly isolated Bacillus clausii GMBAE 42: an alkaline protease producer capable to grow under higly alkaline conditions.

Aims: The isolation and identification of new Bacillus sp. capable of growing under highly alkaline conditions as alkaline protease producers.

Methods And Results: A Bacillus strain capable of growing under highly alkaline conditions was isolated from compost.

Vitrification of pronuclear-stage mouse embryos on solid surface (SSV) versus in cryotube: comparison of the effect of equilibration time and different sugars in the vitrification solution.

The cryopreservation of pronuclear-stage embryos has particular importance in transgenic technology and human assisted reproductive technology (ART). The objective of this study was to improve the efficiency of cryopreservation of pronuclear-stage mouse embryos. Two vitrification methods (solid surface vitrification (SSV) vs.

Development of mouse hybridomas by fusion of myeloma cells with lymphocytes derived from spleen, lymph node, and bone marrow.

Since its discovery by Kohler and Milstein in 1975, hybridoma technology has found a wide use in almost every field of biology and medicine. A general and simple approach for developing monoclonal antibodies is to use splenocytes from immunized mice. In the present study, 10 fusion experiments were carried out to analyze the hybridization efficiencies of mouse myeloma cells with lymphocytes derived from spleen, lymph node, and bone marrow and we found a higher yield of antigen specific antibody producing hybridoma lines when the lymph nodes were used.

Adaptation of cell lines to serum-free culture medium.

The optimum conditions to allow proliferation of cells for the secretion of some growth factors and cytokines and the proliferation of cells in different media that do not contain proteins or serum from animals (serum-free media) were investigated. The culture of cell lines for the commercial production of products involves optimisation of cell proliferation and secretion in media from which the requisite proteins can be economically extracted. Some of these problems were addressed in this study.

Ultrasensitive two-color fluorescence probes for dipole potential in phospholipid membranes.

The principle of electrochromic modulation of excited-state intramolecular proton-transfer reaction was applied for the design of fluorescence probes with high two-color sensitivity to dipole potential, Psid, in phospholipid bilayers. We report on the effect of Psid variation on excitation and fluorescence spectra of two new 3-hydroxyflavone probes, which possess opposite orientations of the fluorescent moiety in the lipid bilayer. The dipole potential in the bilayer was modulated by the addition of 6-ketocholestanol or phloretin and by substitution of dimyristoyl phosphatidylcholine lipid with its ether analog 1,2-di-o-tetradecyl-sn-glycero-3-phosphocholine, and its value was estimated by the reference styryl dye 1-(3-sulfonatopropyl)-4-[beta[2-(di-n-octylamino)-6-naphthyl]vinyl]pyridinium betaine.