Cloning, expression, and pharmacological activity of BmK AS, an active peptide from scorpion Buthus martensii Karsch

BmK AS is a beta long-chain scorpion peptide from the venom of Buthus martensii Karsch (BmK). It was efficiently expressed as a soluble and functional peptide in Escherichia coli, and purified by metal chelating chromatography. About 4.2 mg/l purified recombinant BmK AS could be obtained. The recombinant BmK AS maintained a similar analgesic activity to the natural one in both the mouse-twisting test and hot-plate procedure. It also exhibited antimicrobial activity against both Gram-positive and Gram-negative bacteria. BmK AS is the first long-chain scorpion peptide reported to have antimicrobial activity, and is a valuable molecular scaffold for pharmacological research.

Intracellular localization of integrin-like protein and its roles in osmotic stress-induced abscisic acid biosynthesis in Zea mays

Plants have evolved many mechanisms to cope with adverse environmental stresses. Abscisic acid (ABA) accumulates significantly in plant cells in response to drought conditions, and this is believed to be a major mechanism through which plants enhance drought tolerance. In this study, we explore the possible mechanisms of osmotic stress perception by plant cells and the consequent induction of ABA biosynthesis. Immunoblotting and immunofluorescence localization experiments, using a polyclonal antibody against human integrin beta1, revealed the presence of a protein in Zea mays roots that is similar to the integrin proteins of animals and mainly localized in the plasma membrane. Treatment with GRGDS, a synthetic pentapeptide containing an RGD domain, which interacted specifically with the integrin protein and thus blocked the cell wall-plasma membrane interaction, significantly inhibited osmotic stress-induced ABA biosynthesis in cells, and the GRGDS analog which does not contain the RGD domain had no effect. Our results show that a strong interaction exists between the cell wall and plasma membrane and that this interaction is largely mediated by integrin-like proteins. They also imply that the cell wall and/or cell wall-plasma membrane interaction plays important roles in the perception of osmotic stress. Accordingly, we conclude that the cell wall and/or cell wall-plasma membrane interaction mediated by the integrin-like protein plays important roles in osmotic stress-induced ABA biosynthesis in Zea mays.

Protoplast Fusion between Geotrichum candidium and Phanerochaete chrysosporium to Produce Fusants for Corn Stover Fermentation

Lignin impedes the digestion of corn stover when used as an animal feed. Phanerochaete chrysosporium is an efficient lignindegrader. Geotrichum candidum can be used to produce single-cell protein. In this study, protoplasts of the two fungi were prepared and fused. After screening, one of the fusants, Fusant R1, was selected for corn stover fermentation. It decreased lignin from 109 to 54 g/kg and increased protein from 48 to 67 g/kg in corn stover. Comparison with their parental strains indicated that the fusant obtained the lignin-degrading ability from P. chrysosporium and the protein-accumulating ability from G. candidium.

Neuroprotective effect of hyperbaric oxygen in a rat model of subarachnoid hemorrhage

Acute brain ischemia after subarachnoid hemorrhage (SAH) induces oxidative stress in brain tissues. Up-regulated NADPH oxidase (NOX), a major enzymatic source of superoxide anion in the brain, may contribute to early brain injury after SAH. We evaluated the effects of hyperbaric oxygen (HBO) on protein expression of gp91(phox) catalytic subunit of NOX, lipid peroxidation as a marker of oxidative stress, and on neurological and neuropathological outcomes after SAH. Twenty-nine male Sprague-Dawley rats (300 to 350 g) were randomly allocated to control (sham operation), SAH (endovascular perforation), and SAH treated with HBO groups (2.8 ATA for 2 hours, at 1 hour after SAH). Cerebral blood flow was measured using laser Doppler flowmetry. Rats were sacrificed after 24 hours and brain tissues collected for histology (Nissl staining and gp91 (phox) immunohistochemistry) and biochemistry. Mortality and neurological scores were evaluated. Neuronal injury associated with enhanced gp91 (phox) immunostaining was observed in the cerebral cortex after SAH. The lipid peroxidation product, malondialdehyde, accumulated in the ipsilateral cerebral cortex. HBO treatment reduced expression of NOX, diminished lipid peroxidation, and reduced neuronal damage. HBO caused a drop in mortality and ameliorated functional deficits. HBO-induced neuroprotection after SAH may involve down-regulation of NOX and a subsequent reduction in oxidative stress.

ANEPIII, a new recombinant neurotoxic polypeptide derived from scorpion peptide, inhibits delayed rectifier, but not A-type potassium currents in rat primary cultured hippocampal and cortical neurons

A new recombinant neurotoxic polypeptide ANEPIII (BmK ANEPIII) derived from Scorpion peptide, which was demonstrated with antineuroexcitation properties in animal models, was examined for its action on K+ currents in primary cultured rat hippocampal and cortical neurons using the patch clamp technique in the whole-cell configuration. The delayed rectifier K+ current (I(k)) was inhibited by externally applied recombinant BmK ANEPIII, while the transient A-current (I(A)) remained virtually unaffected. BmK ANEPIII 3 microM, reduced the delayed rectifier current by 28.2% and 23.6% in cultured rat hippocampal and cortical neurons, respectively. The concentration of half-maximal block was 155.1 nM for hippocampal neurons and 227.2 nM for cortical neurons, respectively. These results suggest that BmK ANEPIII affect K+ currents, which may lead to a reduction in neuronal excitability.

Large Uniform-Sized Polymer Beads for Use as Solid-Phase Supports Prepared by Ascension Polymerization

Large uniform-sized polymer beads are desirable for "one-bead-one-compound" applications in the combinatorial synthesis of compound libraries. We have developed a technique for the preparation of large polymer spheres with narrow size distributions. Uniform-sized poly(styrene-co-divinylbenzene) beads with diameters in excess of 1 mm have been prepared by free radical polymerization in an ascension process through a heated column. The size of the beads can be adjusted by the diameter of the injection needle and the injection speed. The resin beads can be made porous by the incorporation of a porogen during the preparation; they reach a specific surface area in excess of 200 m(2)/g. The mechanical properties of the spheres and their use in organic synthesis have been studied.

Nonspherical colloidal crystals fabricated by the thermal pressing of colloidal crystal chips

Nonspherical colloids and their ordered arrays may be more attractive in applications such as photonic crystals than their spherical counterparts because of their lower symmetries, although such structures are difficult to achieve. In this letter, we describe the fabrication and characterization of colloidal crystals constructed from nonspherical polyhedrons. We fabricated such nonspherical colloidal crystals by pressing spherical polymer colloidal crystal chips at a temperature slightly lower than the glass-transition temperature (T(g)) of these polymer colloids. During this process, the polymer microspheres were distinctively transformed into polyhedrons according to their crystal structures, whereas the long-range order of the 3D lattice was essentially preserved. Because a working temperature lower than T(g) effectively prevented the colloidal crystals from fusing into films, the spherical colloidal crystals were transformed greatly under pressure, which lead to obvious change in the optical properties of colloidal crystals. Besides their special symmetry and optical properties, these nonspherical colloidal crystals can be used as templates for 2D or 3D structures of special symmetry, such as 2D nano-networks. We anticipate that this fabrication technique for nonspherical colloidal crystals can also be extended to nonspherical porous materials.

Synthesis of bimetallic nanoshells by an improved electroless plating method

In the Letter, we demonstrate an improved electroless plating method for the synthesis of bimetallic shell particles. The procedure involves a combination of surface reaction, seeding growth, and removal of supporting cores. We modified ammonical AgNO3 in ethanol with a controlled amount of HCHO in the seeding process and a uniform and relatively dense coverage of silver nanoparticle seeds on colloid cores was achieved. Following the second kind of metal plating, we extended this method to prepare continuous bimetallic core-shell and hollow particles with a submicrometer diameter. The morphologies of the bimetallic Cu/Ag and Pt/Ag particles were studied with transmission electron microscopy and scanning electron microscopy, and their crystallinity and chemical composition were confirmed by X-ray diffraction. The prepared materials may be of applied value in areas such as catalysis, optics, and plasmonics.

An analysis of frequency response for the blood flow of volume pulse in microcirculation

In this paper, a frequency analysis for the microcirculation model is introduced to find new microcirculation parameters in the frequency domain. By using Bode Plot of transfer function, we found two characteristic parameters of the model: damping ratio xi and break frequency omega(n). By analyzing the variation of xi and omega(n), it enables us to have better understanding of different states of microcirculation. At low damping, 0<xi<1, the state of microcirculation will be better and better along with the increasing of the omega(n). At over damping, xi> or =1, the state of microcirculation will be worse and worse along with the descending of the omega(n). The results of experiments on 120 subjects are consistent with the analytical results of the model.

Identification of the thymidylate synthase within the genome of white spot syndrome virus

Thymidylate synthase (TS) (EC 2.1.1.45) is essential for thede novosynthesis of dTMP in prokaryotic and eukaryotic organisms. Within the white spot syndrome virus (WSSV) genome, an open reading frame (WSV067) that encodes a 289 amino acid polypeptide showed significant homology to all known TSs from species including mammals, plants, fungi, protozoa, bacteria and DNA viruses. In this study, WSV067 was expressed inEscherichia coli, and the purified recombinant protein showed TS activity in dUMP−folate-binding assays using ultraviolet difference spectroscopy. RT-PCR and Western blot analyses showed that WSV067 was a genuine and early gene. Phylogenetic analysis revealed that WSSV-TS was more closely related to the TSs of eukaryotes than to those from prokaryotes.

Bone sialoprotein promotes bone metastasis of a non-bone-seeking clone of human breast cancer cells

Bone sialoprotein (BSP) is a major non-collagenous protein in mineralized tissues. BSP is also implied to be involved in tumor metastasis through its unique structure. Using the human breast cancer cell line MDA-231, we established both brain-seeking and bone-seeking cell clones. The brain-seeking cells (MDA4-231BR) showed no bone metastasis in an animal model. In this experiment, MDA-231BR cells were transfected with BSP cDNA and inoculated into the hearts of nude mice. All five nude mice which received BSP-transfected MDA-231BR cells developed bone metastases, while no bone lesions were observed in the control group. Histological examination revealed invasion of tumor cells into the endosteal space and erosion of the bone margin. Some animals were crippled due to large lesions. These results suggest that BSP may impart to breast cancer cells the capacity to metastasize and thus play an important role in bone metastasis of malignant tumors.

A specialized plug-in software module for computer-aided quantitative measurement of medical images

This paper presents a specialized system for quantitative measurement of medical images. Using Visual C++, we developed a computer-aided software based on Image-Pro Plus (IPP), a software development platform. When transferred to the hard disk of a computer by an MVPCI-V3A frame grabber, medical images can be automatically processed by our own IPP plug-in for immunohistochemical analysis, cytomorphological measurement and blood vessel segmentation. In 34 clinical studies, the system has shown its high stability, reliability and ease of utility.

Preparation of metallodielectric composite particles with multishell structure

In this article, we demonstrated the synthesis of metallodielectric composite particles comprising a metal shell on a dielectric core and an outer coating of an insulating dielectric layer by depositing silver on silica supporting cores followed by coating of titania. A combination of surface reaction and surface seeding techniques is exploited for the formation of a complete silver shell on silica spheres. The additional outer coating of titania on silver shell particles is then performed by hydrolyzing tetra-n-butyl titanate in ethanol at room temperature. The morphologies of silver shells and titania coating are studied with electron microscopy, and their existences are confirmed with X-ray diffraction and energy-dispersive X-ray measurement.

Heat shock proteins expression in brain stem after subarachnoid hemorrhage in rats

The pathogenesis of brain damage after subarachnoid hemorrhage (SAH) especially at molecular or gene level remains unclear. We used complimentary deoxyribonucleic acid (cDNA) macroarray technique and compared gene expression in brain stem after experimental SAH in rats. The upregulation of several heat shock proteins (HSPs) demonstrated by cDNA array was further confirmed by Western blotting. The expressions of 9 genes were upregulated 30 minutes or 2 days after SAH. They included four upregulated HSPs: HSP90alpha, HSP60, HSP27, and HSP10. Western blotting demonstrated increases in the HSP27 and HSP10 proteins on Day 2. SAH enhanced the induction of several HSP mRNAs in the brainstems, even though the functions of these HSPs after SAH remain unclear.

Analysis of cytokine regulators inducing interferon production by mouse uterine natural killer cells

In mice and women, terminal differentiation of uterine natural killer (uNK) cells commences during endometrial decidualization. Both proliferation and interferon (IFN)-gamma are induced. Uterine NK cell precursors appear to home from secondary lymphoid organs to decidualizing uteri and localize mesometrially to the central decidua basalis, the site of maternal arterial modification at Gestation Days (gd) 9.5-10. In mice, genetic absence of uNK cells results in absence of pregnancy-induced spiral artery modification. Administration of IFN-gamma to uNK-negative pregnant females induces arterial modifications without fetal loss. In this study, we investigated the roles of cytokines, known in other tissues to differentiate and activate NK cells, in induction of IFN-gamma production in normal mouse implantation sites. Fecundity evaluation, implantation site morphometry, and IFN-gamma quantification in interleukin (IL)-12p40(0/0), IL-18(0/0), dual IL-12p40(0/0)/IL-18(0/0) and congenic strains revealed the importance of both IL-12 and IL-18 in the induction of spiral artery modification and IFN-gamma synthesis. Immediately after implantation, IL-18 was localized transiently to decidual cells, but by gd8, IL-18 was produced solely by uNK cells, suggesting that early uNK cells are activated by stroma and lymphocyte-derived signals maintain later uNK cell activation. Mesometrial tissue of C57Bl/6J mice was examined by reverse transcription polymerase chain reaction assay in virgin, early postimplantation, and midgestation females for expression of the heterodimeric cytokines IL-23 (composed of IL-12p40 and a novel alpha chain), IL-27 (composed of two IL-12-related chains) and IL-27R. No expression was detected in virgin uteri. The four genes were induced by gd6, and uNK cells isolated from midgestation transcribed IL-23alpha and IL-27R. This study advances the understanding of uNK cell activation during normal pregnancy.

Multiple hyperbaric oxygenation (HBO) expands the therapeutic window in acute spinal cord injury in rats

Hyperbaric oxygenation (HBO) therapy has been reported to improve neurological recovery following spinal cord injury (SCI). In the present study, we examined whether multiple HBO expands the therapeutic window for acute SCI. Single HBO (2.8 ATA, 1 hour) treatment was used at 30 minutes, 3 hours, and 6 hours following SCI, and serial HBO treatment (once daily for 1 week) at 6 hours and 24 hours post-injury. Mild SCI was induced by adjusting the height for a weight drop insult (10 g) to 6.25 mm above the exposed spinal cord. The group of animals receiving a single HBO intervention beginning at 30 minutes and 3 hours, or serial HBO treatment starting at 6 hours following the injury had a significantly better neurological recovery than animals with SCI only. The results of this study demonstrate that multiple HBO expands the therapeutic window for acute SCI to 6 hours after injury, further that serial HBO administration is superior to single HBO therapy.

Apoptosis, blood-brain barrier, and subarachnoid hemorrhage

This study was undertaken to investigate the role of apoptosis in the integrity of blood-brain barrier (BBB) in subarachnoid hemorrhage (SAH). BBB permeability changes were examined and found increased on day 7 in a double hemorrhage rat model using Evans blue dye. The BBB permeability increase is coincidental to brain microvascular endothelial cell apoptosis (expression of caspase-8 and -9) occurring on Day 7. However, caspase-8 and caspase-9 inhibitors failed to protect the BBB. Considering that treatment did not completely inhibit apoptosis in brain microvascular endothelial cells, higher doses, earlier and/or multiple applications, and, possibly, more potent caspase inhibitors may be needed.

Isolation, purification, and N-terminal partial sequence of an antitumor peptide from the venom of the Chinese scorpion Buthus martensii Karsch

An antitumor peptide (ANTP) was isolated and purified from the venom of the Chinese scorpion Buthus martensii Karsch. The purification procedure included gel filtration on Sephadex G-50 and Superdex 30 high resolution chromatography, Phenyl Sepharose 6 Fast Flow chromatography, and SP-Sepharose Fast Flow chromatography. Its homogeneity was demonstrated by size exclusion HPLC on TSK G2000 SW. The isoelectric point is more than 10 by pH 3-10 range isoelectric focusing. ANTP has a relative molecular mass of 6280, calculated from the measurement of 16.5% SDS-PAGE. The pharmacological tests showed that ANTP has antitumoral effects in the mouse S-180 fibrosarcoma model and Ehrlich ascites tumor model. Amino acid analysis suggested the ANTP is rich in glycine and does not have histidine and threonine. The sequence of the first 25 N-terminal residues is as follows: Val-Arg-Asp-Gly-Tyr-Ile-Ala-Asp-Asp-Lys-Asn-Cys-Ala-Tyr-Phe-Cys-Gly-Arg-Asn-Ala-Tyr-Cys-Asp-Asp-Glu.

Na(+)/Ca(2+) exchanger expression in the developing rat cortex

The Na(+)/Ca(2+) exchanger (NCX) participates in the regulation of neuronal Ca(2+) homeostasis and is also believed to be involved in the neuronal responses to hypoxia. However, there are very limited data on how NCX mRNA and protein expression are regulated during brain development. In the present study, we sought to elucidate the developmental expression of NCX1 and NCX2 in the rat cortex from late fetal to adult stages using reverse transcription-polymerase chain reaction and western blot assays. The primers for NCX1 mRNA targeted the alternative splicing domain to allow differentiation between NCX1 splice variants. Our results show that: (1) only two NCX1 mRNA splice variants (NCX1.5 and NCX1.4) are present in the cortex and their expression is age-dependent; (2) total NCX1 mRNA levels are low in fetal tissue, reach maximum density at postnatal day 8 and substantially decline with further maturation; (3) NCX2 mRNA density is significantly greater than total NCX1 mRNA for all ages and increases markedly during maturation from fetus/neonate to adult; and (4) NCX1 protein expression is lowest in late fetal cortex and reaches maximum levels after 2 weeks postnatally, even though expression levels are not significantly different between newborn and adult animals. Also, we found a similar NCX1 protein trend in the subcortical and cerebellar regions during development. From these data we suggest that NCX1 and NCX2 are differentially expressed in the cortex with a predominance of NCX2 levels during postnatal development. We speculate that the developmental increase in NCX2 expression is responsible for the overall increase in Na(+)/Ca(2+) exchange capacity during maturation.

Upregulation of small GTPase RhoA in the basilar artery from diabetic (mellitus) rats

The goal of this study was to determine whether RhoA, a small GTPase, might be involved in the development of cerebral pathogenesis in diabetes. Male SD rats (n = 120) were divided into six groups: diabetic for 2, 4, 8 weeks, and an age-matched control group. Diabetes was induced by intravenous injection of streptozotocin (50 mg/kg). RhoA mRNA expression in basilar artery was measured by competitive RT-PCR. RhoA mRNA level was significantly increased in 4 weeks (184.1 +/- 28.5%, n = 7) and 8 weeks (218.7 +/- 24.5%, n = 7) after STZ injection compared to the age matched control basilar arteries (P < 0.05). Western blot was used to measure the membrane binding RhoA level to represent the activity of RhoA. We found that RhoA activity was strikingly increased in the diabetic basilar artery (n = 10 in each groups) compared to control basilar artery after STZ injection. Our data demonstrated that there was an upregulation of RhoA in the basilar artery of STZ induced diabetic rats, suggesting that RhoA might be involved in the cerebral vascular pathogenesis during diabetes mellitus.

Optimum ratio of histidine in the piglet ideal protein model and its effects on the body metabolism. II. Optimum ratio of histidine in 10-20 KG piglet ideal protein and its effects on blood parameters

Two growth trails were conducted to determine the optimum ratio of histidine in 10-20 kg piglet ideal protein model. Four diets containing 0.23%, 0.31%, 0.39% and 0.47% digestible histidine (0, 0.08%, 0.16%, 0.24% crystalline histidine supplemented into the basal diet) were fed to 96 piglets of mean initial body weight 10.3 +/- 1.08 kg for 18 d in Experiment 1. Average daily gain, average daily feed intake and feed conversion efficiency were inhibited (P < 0.05) with the diet containing 0.23% digestible histidine. Performance was maximized with 0.31% digestible histidine. As the dietary histidine increased, blood urea nitrogen and serum cholesterol concentration were influenced significantly. The concentrations of serum histamine and free histidine did not change with increase in digestible histidine from 0.23 to 0.31%, but higher supplementation resulted in a significant linear increase in both serum parameters. It was concluded that the dietary level of 0.23% digestible histidine does not meet the requirement of 10-20 kg piglets. Based on the results from Experiment 1, Experiment 2 was designed to determine the optimum ratio of lysine:histidine in the ideal protein model of 10-20 kg piglet. Ninety-six Large White x Landrace piglets weighing 10.2 +/- 0.88 kg were divided into 4 groups. They were fed four diets containing 0.26, 0.29, 0.32 or 0.35% digestible histidine, formulated by adding 0.03, 0.06, 0.09 or 0.12% crystalline histidine to the basal diet. The trial lasted for 21 days. Results showed that performance was significantly improved with 0.32 and 0.35% digestible histidine. As dietary histidine increased, blood urea nitrogen tended to decrease but not significant at P < 0.05. Serum cholesterol concentration increased with an increase in dietary histidine level and reached a maximum at 0.35%. Serum histamine increased with increasing dietary histidine. Free serum histidine increased linearly with increased dietary histidine. From both experiments it was concluded that the digestible histidine requirement for 10-20 kg piglets was 0.31% and that the optimum ratio of dietary lysine to histidine should be 100:30. The concentrations of cholesterol, histamine and free histidine in serum were sensitive parameters to measure changes in dietary histidine levels.

Optimum ratio of histidine in the piglet ideal protein model and its effects on body metabolism. I. Basal diet formulation based on digestible amino acids according to the ideal protein model for 10 to 20 kg piglets

A 4 x 4 Latin square design was used to determine ileal apparent digestibility of amino acids (AAs) in corn, soybean meal, feather meal and dried whey in young pigs. The data were then to be used in formulating a basal diet for studies on AA metabolism in young pigs. Eight castrates T-cannulated at terminal ileum (average initial body weight 12.5 +/- 0.62 kg) were divided into 4 groups on the basis of body weight and transferred to individual metabolism crates. They were then fed four experimental diets containing the four feedstuffs to be tested (corn, soybean meal, feather meal and dried whey). The trial lasted 20 days, which included 4 five-day periods for ileal digesta collection. It was found that the digestibility of the AAs was similar to that reported in literature. Based on the findings a basal diet for this research was formulated according to an ideal protein model for the 10 to 20 kg piglet, on the basis of digestible AAs and containing 14.13 MJ/kg digestible energy, 18.22% crude protein, 1.04% digestible lysine and 0.23% digestible histidine.

Role of MAPK in chronic cerebral vasospasm

This study was undertaken to investigate the role of p44/42 MAPK in a dog double hemorrhage model of subarachnoid hemorrhage (SAH), and whether MEK inhibitors can alter the degree of SAH-induced vasoconstriction. The diameter of the basilar artery, which was compared with day 0 angiogram, decreased gradually in a time-dependent manner from day 3 (80%), day 5 (68%) through day 7 (53.5%). The level of MAPK (p44/42) immunoprecipitation peaked on day 3 and remained enhanced through day 7 (P < 0.05). MEK inhibitor PD98059 significantly reduced p44/42 MAPK immunoprecipitation and significantly reversed vasospasm and increased residual diameter to 79.0% on day 7. These results demonstrated that p44/42 MAPK kinase is involved in the pathogenesis of cerebral vasospasm. The MEK inhibitor PD98059 might be useful in the treatment of vasospasm.