Improved Photoelectrocatalytic Performance for Water Oxidation by Earth-Abundant Cobalt Molecular Porphyrin Complex-Integrated BiVO4 Photoanode

An earth-abundant, low-cost cobalt porphyrin complex (CoTCPP) is designed as a molecular catalyst to work on three-dimensional BiVO4 film electrode for water oxidation for the first time. Under illumination of a 100 mW cm(-2) Xe lamp, the CoTCPP-functionalized BiVO4 photoanode exhibits a 2-fold enhancement in photocurrent density at 1.23 V vs RHE and nearly a 450 mV cathodic shift at 0.5 mA cm(-2) photocurrent density relative to bare BiVO4 in 0.1 M Na2SO4 (pH = 6.8). Simultaneously, stoichiometric oxygen and hydrogen are generated with a faradic efficiency of 80% over 4 h. The activity and stability of the BiVO4 photoanode are dramatically increased by molecular CoTCPP, giving rise to higher performance than previously reported noble metal ruthenium complex-modified BiVO4 photoanode. By using hydrogen peroxide as the hole scavenger, we demonstrate that molecular CoTCPP catalyst greatly suppresses the hole-electron recombination on the surface of BiVO4 semiconductor, which offers a promising route toward high efficiency, low cost, practical solar fuel generation device.

Hole-Accepting-Ligand-Modified CdSe QDs for Dramatic Enhancement of Photocatalytic and Photoelectrochemical Hydrogen Evolution by Solar Energy

Solar H2 evolution of CdSe QDs can be significantly enhanced simply by introducing a suitable hole-accepting-ligand for achieving efficient hole extraction and transfer at the nanoscale interfaces, which opens an effective pathway for dissociation of excitons to generate long-lived charge separation, thus improving the solar-to-fuel conversion efficiency.

Relationship between TLR4 and CCL2 expression and recurrent spontaneous abortion

The increasing incidence of recurrent spontaneous abortion (RSA) severely affects women's health. The involvement of the immune system during pregnancy and its contribution to RSA draw researchers' attention. Both Toll-like receptor 4 (TLR4) and chemokine (C-C motif) ligand 2 (CCL2) have been linked to various pregnancy disorders. In this study, we quantified TLR4 and CCL2 levels in a case-control study in order to elucidate the correlation between these factors and RSA, and the potential to use them as disease markers. A total of 36 RSA patients and 36 healthy control individuals were recruited for the donation of decidual and chorionic tissues and venous blood samples. Fluorescent quantitative-polymerase chain reaction was used to measure mRNA levels and enzyme linked immunosorbent assay was used to quantify serum levels of TLR4 and CCL2. RSA patients had higher TLR4 and CCL2 mRNA levels compared to controls (P < 0.05). Serum levels of the two factors were also significantly higher in RSA patients than in the control group (P < 0.05). Positive correlations were found between serum levels and tissue mRNA levels of TLR4 and CCL2. In conclusion, both TLR4 and CCL2 were closely related to the occurrence of RSA, suggesting that serum TLR4 and CCL2 levels could be used as indices for monitoring RSA in pregnant women.

Clinical efficacy of fiberoptic ductoscopy in combination with ultrasound-guided minimally invasive surgery in treatment of plasma cell mastitis

OBJECTIVES

To analyze clinical efficacy between fiberoptic ductoscopy plus ultrasound-guided minimally invasive irrigation and lesion resection in treating plasma cell mastitis (PCM), aiming to provide clinical evidence for treating PCM.

MATERIALS AND METHODS

119 patients undergoing fiberoptic ductoscopy plus ultrasound-guided minimally invasive surgery in Ningxia People's Hospital were allocated into the breast duct irrigation group, and 95 counterparts receiving lesion resection in the Affiliated Hospital of Ningxia Medical University into the control group. Clinico-pathological characteristics and therapeutic effect were compared between two groups.

RESULTS

The cure rate in the breast duct irrigation group was 98.31% (117/119), significantly higher than 90.53% in the control group (p < 0.05). In the breast duct irrigation group, overall treatment time was 20.13 days, significantly longer than 15.15 days in the control group (p < 0.05). During postoperative follow-up, no recurrence was observed, significantly lower compared with 48.8% (42/86) in the control group. The degree of satisfaction in the breast duct irrigation group was 95.79% (114/119), significantly higher compared with 74.74% (71/95) in the control group.

CONCLUSIONS

Fiberoptic ductoscopy plus with ultrasound-guided minimally invasive drainage is a novel and effective treatment of PCM with high cure rate, low recurrence rate, slight pain, and effectively maintains breast integrity.

Cloning and stress response analysis of the PeDREB2A and PeDREB1A genes in moso bamboo (Phyllostachys edulis)

Moso bamboo is a large woody bamboo with the highest ecological, economic, and cultural value among all bamboos in Asia. However, environmental stress influences its growth and development and limits its geographic distribution. Therefore, improving its resistance to environmental stress is extremely important. Dehydration responsive element binding (DREB) transcription factors perform an important role in the regulation of stress-related genes, enhancing the resistance of plants to abiotic stress. In the current study, two novel DREB genes, PeDREB2A and PeDREB1A (Gene ID No. PH01000046G1730 and PH01000668G0350), were isolated from moso bamboo and the sequences were identified and characterized (coding sequence lengths were 795 and 825 bp, respectively). The PeDREB2A and PeDREB1A proteins were estimated to have typical AP2/ERF domains, molecular weights of 28.96 and 28.84 kDa, and isoelectric points of 9.47 and 5.34, respectively. RT-PCR analysis revealed that PeDREB2A and PeDREB1A were tissue-specific genes, expressed in leaves, young stems, and roots, with similar expression levels in leaves and young stems. qRT-PCR analysis of leaves demonstrated that PeDREB2A transcription levels rapidly accumulate following exposure to drought and salt stress, peaking at 12 and 0.5 h, respectively, but only low expression levels were observed under cold stress. PeDREB1A exhibited a strong response to cold stress, reaching a peak in expression 3 h after exposure, but demonstrated only a slight response to drought and salt stress. In roots, PeDREB2A was down-regulated, and PeDREB1A was initially upregulated but then declined, under stress conditions. Two plant expression vectors, pCAMBIA2300- CaMV35S-PeDREB2A and pCAMBIA2300-CaMV35S-PeDREB1A were also successfully constructed.

Molecular cloning, characterisation and tissues expression analysis of the goose (Anser cygnoides) vasoactive intestinal peptide (VIP) gene

1. Vasoactive intestinal peptide (VIP) is involved in the control of prolactin (PRL) release and plays a pivotal role as a regulator of reproductive behaviour and neuroendocrine secretion in birds. 2. In this study, a 941-bp cDNA fragment covering the complete coding region (CDS) of goose VIP gene was identified. The cDNA contains a 32-bp 5'-untranslated region (UTR), a 603-bp CDS and a 306-bp 3'-UTR containing two ATTTA sequence elements, two polyadenylation signals (AATAAA) and a 25-bp poly (A) tail. 3. Seven exons and 6 introns were identified, and both the cDNA and genomic DNA sequences showed high identity with those of other species. 4. The sequence analysis indicated that there were two alternatively spliced transcripts the long transcript (VIP-1) encoded both VIP and peptide histidine isoleucine exons and the short one (VIP-2) only encoded VIP. 5. RT-PCR analysis indicates that the expression level of the VIP-1 is much lower than that of VIP-2, and that VIP-1 is negligible or absent in muscle, abdominal fat, ovary and spleen, whereas VIP-2 is widely distributed in all the examined tissues. 6. A total of 12 single nucleotide polymorphisms (SNPs), including 2 SNPs located in the coding region and 10 variations in intron regions, were identified in goose VIP gene.

The effectiveness of an integrated multicomponent program for adolescent smoking cessation in Taiwan

If adolescents do not receive appropriate assistance in quitting smoking, they are highly likely to become regular smokers when they enter adulthood. Thus, an effective smoking-cessation program is required. A program was designed based on both the smoking-cessation barriers reported by students and effective strategies derived from the literature. We assigned 143 student smokers from 6 vocational high schools to intervention (n=78) and comparison groups (n=65). Data were collected at the baseline, the end of the program, and 1- and 4-month follow-up time points. For the intervention group, the smoking-abstinence rates confirmed using the urine cotinine test were 22.73% at the end of the program and 20.75% at the 4-month follow-up point. Days smoked in the past month, number of cigarettes smoked per day, and the Fagerström Test for Nicotine Dependence score of the intervention group decreased at all of the time points. The group differences in these variables were statistically significant; the magnitude of effect sizes ranged from 0.44 to 0.95. Multicomponent programs addressing smoking-cessation barriers that students encounter can help adolescents quit smoking.

Molecular cloning, expression and polymorphism of goose LRP8 gene

1. The low-density lipoprotein receptor-related protein 8 (LRP8), a member of the low-density lipoprotein receptor (LDLR) gene family, participates in the supplying of lipid during follicular development. The objective of the study was to identify and characterise the LRP8 gene in goose. 2. A 2867 bp fragment that covered the complete coding region (CDS) of goose (Anser cygnoides) LRP8 gene was cloned. It encoded a protein of 917 amino acid residues containing a 24-amino acid signal peptide and 5 functional domains. The goose LRP8 showed high nucleic acid and amino acid identities with those in other species. 3. Similarly to duck LRP8 gene, two splice variants of LRP8, LRP8-1 (containing 8 ligand-binding repeats) and LRP8-2 (containing 7 ligand-binding repeats), were identified in goose. 4. Semi-quantitative RT-PCR analysis indicates that the LRP8-1 transcript is expressed in heart, liver, spleen, lung, kidney, breast muscle, duodenum, hypothalamus, pituitary and ovary, negligible or absent in sebum and oviduct, and the LRP8-2 transcript is widely expressed in all examined tissues. 5. A total of 7 SNPs were identified in the coding region of the goose LRP8 gene.

Coupled vectors resolution method for chemometric calibration with three-way data

A new second-order calibration procedure, the coupled vectors resolution (COVER) method, has been developed. The objective of the method is to seek a couple of vectors that minimize a least-squares criterion. With the knowledge indispensable for quantitation, the method yields direct solutions to various cases of second-order calibration. Moreover, it allows a statistically plausible way to make use of multisample information. In the case of multiple calibration samples, the method uses the calibration samples to resolve the profiles of the analytes in each order, and then calculates the concentrations of the analytes. This offers the advantage that unknown mixtures newly collected can be predicted in a direct manner. In the case of one calibration sample, the method provides an effective way to utilize the information of spectral profiles of the analytes. Results of simulated experiments and a real analytical example show that the proposed method produces acceptable performance in profile resolution and concentration estimation.

Inter-unit variability in two ParvoMedics TrueOne 2400 automated metabolic gas analysis systems

Knowing the inter-unit variability, especially the technological error, is important when using many physiological measurement systems, yet no such inter-unit analysis has been undertaken on duplicate automated gas analysis systems. This study investigated the inter-unit performance of two identical ParvoMedics TrueOne 2400 automated gas analysis systems during a range of submaximal steady-state exercises performed on an electromagnetic cycle ergometer. Fifteen adult males were tested on two separate days a rest, 30, 60, 90, and 120 Watts with the duplicate gas analysis units arranged (1) collaterally (2 min of steady-state expired gas was alternately passed through each system), and (2) simultaneously (identical steady-state expired gas was passed simultaneously through both systems). Total within-subject variation (biological + technological) was determined from the collateral tests, but the unique inter-unit variability (technological error between identical systems) was shown by the simultaneous tests. Absolute percentage errors (APE), coefficient of variations (CV), effect sizes and Bland-Altman analyses were undertaken on the metabolic data, including expired ventilation (V (E)), oxygen consumption (VO(2)) and carbon dioxide production (VCO(2)). The few statistically significant differences detected between the two duplicate systems were determined to have small or trivial effect sizes, and their magnitudes to be of little physiological importance. The total within-subject variations for VO(2), VCO(2) and V (E) each equated to a mean CV and mean APE value of ~4 and ~6 %, whilst the respective inter-unit technological errors equated to ~1.5 and ~2.1 %. The two ParvoMedics TrueOne 2400 systems demonstrated excellent inter-unit agreement.

Isolation and characterization of eight polymorphic microsatellite loci for the coconut pest, Brontispa longissima (Coleoptera: Hispidae)

Brontispa longissima is one of the most serious insect pests of coconut in Southeast Asia; it was first discovered on Hainan Island in June 2002. Despite the economic risk associated with this pest, genetic aspects of the invasion process have remained relatively unexplored. Using microsatellite markers, we investigated the population structure, genetic variability and pattern of invasion in various geographic populations. The methodology was based on a modified biotin-capture method. Eight polymorphic microsatellite loci were isolated and characterized for the pest. The allele number per locus varied from 2 to 3 (N = 30). The expected and observed heterozygosities of the eight loci ranged from 0.042 to 0.509 and from 0.042 to 0.963, respectively. Although the frequency of polymorphisms was not very high in this population, the microsatellite loci that were isolated will be useful for investigating the genetic diversity and migration routes of B. longissima populations.

Generation of a novel factor IX with augmented clotting activities in vitro and in vivo

BACKGROUND

Hemophilia B is an X-linked inherited disorder caused by the lack of functional factor IX (FIX). Currently, treatment of hemophilia B is performed by intravenous infusion of plasma-derived or recombinant FIX.

OBJECTIVE

In an effort to reduce factor usage and cost, we investigated the potential use of FIX variants with enhanced specific clotting activity.

METHODS

Seven recombinant FIX variants using alanine replacement were generated and assayed for their activity in vitro and in vivo.

RESULTS

One variant containing three substitutions (V86A/E277A/R338A, FIX-Triple) exhibited 13-fold higher specific clotting activity and a 10-fold increased affinity for human FVIIIa compared with FIX-wild-type (FIX-WT) and was thus investigated systematically in vivo. Liver-specific FIX-Triple gene expression following hydrodynamic plasmid delivery revealed a 3.5-fold higher specific clotting activity compared with FIX-WT. Human FIX-Triple and FIX-WT knock-in mice were generated and it was confirmed that FIX-Triple has 7-fold higher specific clotting activity than FIX-WT under normal physiological conditions. Protein infusion of FIX-Triple into hemophilia B mice resulted in greater improvement of hemostasis than that achieved with FIX-WT. Moreover, tail-vein administration of a serotype 8 recombinant Adeno-associated vector (AAV8) expressing either FIX-WT or FIX-Triple in hemophilia B mice demonstrated a 7-fold higher specific clotting activity of FIX-Triple than FIX-WT.

CONCLUSIONS

Our results indicate that the FIX-Triple variant exhibits significantly enhanced clotting activity relative to FIX-WT due to tighter binding to FVIIIa, as demonstrated both in vitro and in vivo. Therefore, FIX-Triple is a good candidate for further evaluation in protein replacement therapy as well as gene-based therapeutic strategies.

Ageing of alpha-chymotrypsin: Cannibalistic and hydroxide ion reactions

The loss of catalytic activity (irreversible denaturation) of alpha-chymotrypsin (EC 3.4.21.1) as a function of pH between 6 and 13 is described. Around neutrality the irreversible denaturation is second order with respect to enzyme. At high pH, the irreversible denaturation is first order with respect to enzyme and also with respect to hydroxide ion. The first- or second-order dependency on enzyme concentration has been shown both by the time course of denaturation and by the effect of enzyme concentration on the rate of denaturation. The first-order dependency on hydroxide ion was shown by a plot of the logarithm of the rate constant vs. pH. These enzyme inactivations are peptide bond cleavages at all pH values. From the kinetics, the irreversible denaturation can be described as a cannibalistic reaction of two enzyme molecules around neutrality or as a reaction of one enzyme molecule plus one hydroxide ion at high pH.

Elimination of cannibalistic denaturation by enzyme immobilization or inhibition

The cannibalistic denaturation of alpha-chymotrypsin (EC 3.4.21.1) around neutral pH can be eliminated by immobilization (insolubilization) of the enzyme or by inhibition by specific reversible inhibitors, but the high-pH denaturation cannot be. The denaturation of the immobilized enzyme at high pH follows first-order kinetics, just as the denaturation of the soluble enzyme does. These results lend credence to the description of the denaturation of chymotrypsin as cannibalistic around neutrality and due to a hydroxide ion reaction at high pH; this interpretation followed from kinetic arguments given in the previous article [Wu, H.-L., Wastell, A. & Bender, M. L. (1981) Proc. Natl. Acad. Sci. USA 78, 4116-4117]. Elimination of denaturation around neutrality by immobilization may be the reason why membrane-bound enzymes are so common in vivo.

Human plasminogen kringle 1-5 reduces atherosclerosis and neointima formation in mice by suppressing the inflammatory signaling pathway

BACKGROUND

Activation of vascular endothelial cells plays an important role in atherogenesis and plaque instability. Recent research has demonstrated that late-stage inhibition of plaque angiogenesis by angiostatin (kringle 1-4) reduces macrophage accumulation and slows the progression of advanced atherosclerosis. Kringle 1-5 (K(1-5)) is a variant of angiostatin that contains the first five kringle domains of plasminogen.

OBJECTIVE

To investigate whether K(1-5) has an inhibitory effect on early-stage atherosclerosis, using the apolipoprotein E (ApoE)-deficient mouse model and a carotid artery ligation model.

METHODS

ApoE-deficient mice received K(1-5) treatment for 4 weeks, and the severity of aortic atherosclerosis was measured. In the ligation model, the left common carotid arteries of C57BL/6 mice were ligated near the carotid bifurcation, and the mice received K(1-5) for 4 weeks. Human umbilical vein endothelial cells were pretreated with K(1-5) before tumor necrosis factor-alpha (TNF-alpha) treatment to explore the anti-inflammatory effect of K(1-5).

RESULTS

The areas of the lesion in the aortas of ApoE-deficient mice that received K(1-5) treatment were notably decreased, and the formation of carotid neointima in the C57BL/6 mice was decreased by treatment with K(1-5). Expression of TNF-alpha-induced intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 was inhibited by K(1-5) treatment, possibly via downregulation of translocation of nuclear factor-kappaB and expression of reactive oxygen species.

CONCLUSIONS

K(1-5) reduced atherosclerosis and neointima formation in mice, possibly through inhibition of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expression in endothelial cells.

A new procedure for correction of severe inverted nipple with two triangular areolar dermofibrous flaps

Severely inverted nipples are invaginated deeply and present many aesthetic, functional, and psychological problems. Many methods have been proposed for correction of this deformity. The authors describe a new simple method using two broad triangular areolar dermofibrous flaps. This method affords sufficient tissue to fill the dead space. Furthermore, it furnishes bulk to drive up the nipple, and because the cross lay of the flap and the epidermis make the areola circular and small, it provides sufficient areolar tissue for reconstruction of the defective nipple. The manipulation of postoperative "donut" traction is simple and useful. This method was used to correct 14 nipples of 9 patients successfully without any postoperative problems and with minimal scars and no recurrence of inversion. It is an ideal surgical procedure for the severely inverted nipple.

Hydroxychavicol, a novel betel leaf component, inhibits platelet aggregation by suppression of cyclooxygenase, thromboxane production and calcium mobilization

BACKGROUND AND PURPOSE

Platelet hyperactivity is important in the pathogenesis of cardiovascular diseases. Betel leaf (PBL) is consumed by 200-600 million betel quid chewers in the world. Hydroxychavicol (HC), a betel leaf component, was tested for its antiplatelet effect.

EXPERIMENTAL APPROACH

We tested the effect of HC on platelet aggregation, thromboxane B(2) (TXB(2)) and reactive oxygen species (ROS) production, cyclooxygenase (COX) activity, ex vivo platelet aggregation and mouse bleeding time and platelet plug formation in vivo. The pharmacokinetics of HC in rats was also assessed.

KEY RESULTS

HC inhibited arachidonic acid (AA) and collagen-induced platelet aggregation and TXB(2) production. HC inhibited the thrombin-induced TXB(2) production, but not platelet aggregation. SQ29548, suppressed collagen- and thrombin-induced TXB(2) production, but not thrombin-induced platelet aggregation. HC also suppressed COX-1/COX-2 enzyme activity and the AA-induced ROS production and Ca(2+) mobilization. HC further inhibited the ex vivo platelet aggregation of platelet-rich plasma (>100 nmole/mouse) and prolonged platelet plug formation (>300 nmole/mouse) in mesenteric microvessels, but showed little effect on bleeding time in mouse tail. Moreover, pharmacokinetics analysis found that more than 99% of HC was metabolized within 3 min of administration in Sprague-Dawley rats in vivo.

CONCLUSIONS AND IMPLICATIONS

HC is a potent COX-1/COX-2 inhibitor, ROS scavenger and inhibits platelet calcium signaling, TXB(2) production and aggregation. HC could be a potential therapeutic agent for prevention and treatment of atherosclerosis and other cardiovascular diseases through its anti-inflammatory and antiplatelet effects, without effects on haemostatic functions.

Post-translational modification of delta antigen of hepatitis D virus

The hepatitis delta virus (HDV) genome has only one open reading frame, which encodes the viral small delta antigen. After RNA editing, the same open reading frame is extended 19 amino acids at the carboxyl terminus and encodes the large delta antigen. These two viral proteins escort the HDV genome through different cellular compartments for the complicated phases of replication, transcription and, eventually, the formation of progeny virions. To orchestrate these events, the delta antigens have to take distinct cues to traffic to the right compartments and make correct molecular contacts. In eukaryotes, post-translational modification (PTM) is a major mechanism of dictating the multiple functions of a single protein. Multiple PTMs, including phosphorylation, isoprenylation, acetylation, and methylation, have been identified on hepatitis delta antigens. In this chapter we review these PTMs and discuss their functions in regulating and coordinating the life cycle of HDV.

Identification of rice black streaked dwarf virus in different cereal crops with dwarfing symptoms in China

This report describes isolation of virus particles from plants of rice, maize, wheat and sorghum with symptoms of dwarfing collected from two provinces of China, purification of double-stranded RNA (dsRNA) from the virus particles, and synthesis of full-length cDNAs of genome segments 9 (S9) and 10 (S10) by reverse transcription-polymerase chain reaction (RT-PCR). Sequence analysis showed that the S9 sequences of the Chinese isolates and a Japanese rice black-streaked disease virus (RBSDV) isolate were very similar (89.1-89.6% homology at nucleotide level and 92.3-92.9% and 95.8-98.6% homology at amino acid level for ORF1 and ORF2, respectively). Analogical similarity was found also for the S10 sequences of the isolates under comparison: 93.0-95.4% homology at nucleotide level and 96.2-97.0% homology at amino acid level. However, there was a relatively lower similarity for S9 and S10 segments ofthe Chinese isolates and an Italian maize rough dwarf virus (MRDV) isolate. The phylogenetic analysis indicated that the Chinese isolates that infect rice, maize, wheat and sorghum and cause similar symptoms could represent the same virus species, RBSDV.

Studies of a novel human thrombomodulin immobilized substrate: surface characterization and anticoagulation activity evaluation

Immobilization of the anticoagulative or antithrombogenic biomolecule has been considered as one of the important methods to improve the blood compatibility of artificial biomaterials. In this study, a novel immobilization reaction scheme was utilized to incorporate the human thrombomodulin, an endothelial cell associated glycoprotein, onto the cover glass surface with an aim to develop an anticoagulative substrate. Trichlorotriazine and amino-terminated silane were employed as the coupling agents, while the polyethylene glycol with a molecular weight of 1500 was used as the spacer in this reaction scheme. Protein C activation assay indicated the immobilized human thrombomodulin still has this coenzymatic activity but is lower, possibly due to the conformation variation by the coupling agents. In vitro platelet adhesion assay has demonstrated the surface with immobilized human thrombomodulin is much less platelet-activating than others. Therefore, the novel reaction scheme proposed here is very promising for future development of an anticoagulative silicon or cover glass substrate (e.g. implantable sensor or biochip) by the immobilization of antithrombogenic protein, such as the human thrombomodulin in this study.

Inducing the cell cycle arrest and apoptosis of oral KB carcinoma cells by hydroxychavicol: roles of glutathione and reactive oxygen species

Hydroxychavicol (HC; 10 - 50 microM), a betel leaf component, was found to suppress the 2% H(2)O(2)-induced lucigenin chemiluminescence for 53 - 75%. HC (0.02 - 2 microM) was also able to trap superoxide radicals generated by a xanthine/xanthine oxidase system with 38 - 94% of inhibition. Hydroxyl radicals-induced PUC18 plasmid DNA breaks was prevented by HC (1.6 - 16 microM). A 24-h exposure of KB cells to HC (0.5, 1 mM) resulted in 54 - 74% cell death as analysed by a 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. HC (10, 50 microM) further suppressed the growth of KB cells (15 and 76%, respectively). Long-term colony formation of KB cells was inhibited by 51% with 10 microM HC. Pretreatment of KB cells with 100 microM HC inhibited the attachment of KB cells to type I collagen and fibronectin by 59 and 29%, respectively. Exposure of KB cells to 0.1 mM HC for 24 h resulted in cell cycle arrest at late S and G2/M phase. Increasing the HC concentration to 0.25 and 0.5 mM led to apoptosis as revealed by detection of sub-G(0)/G(1) peaks with a concomitant decrease in the number of cells residing in late S and G(2)/M phase. Inducing the apoptosis of KB cells by HC was accompanied by marked depletion in reduced form of GSH (>0.2 mM) and the increasing of reactive oxygen species production (>0.1 mM) as analysed by CMF- and DCF-single cell fluorescence flow cytometry. These results indicate that HC exerts antioxidant property at low concentration. HC also inhibits the growth, adhesion and cell cycle progression of KB cells, whereas its induction of KB cell apoptosis (HC>0.1 mM) was accompanied by cellular redox changes.

Molecular cloning and expression of woodchuck granulocyte-macrophage colony stimulating factor

Granulocyte-macrophage colony stimulating factor (GM-CSF) has immunoregulatory and antiviral effects, and may thus be promising for the treatment of chronic hepatitis B. Using woodchuck hepatitis virus (WHV)-infected woodchuck as an animal model to test the efficacy and safety of GM-CSF on the therapy of chronic hepatitis B, woodchuck GM-CSF will be required due to the apparent species-specific activity of GM-CSF. The cDNA of woodchuck GM-CSF was cloned using reverse transcription-polymerase chain reaction (RT-PCR) with primers deriving from highly conserved regions of GM-CSF genes from other species. The deduced amino acids, including the signal peptide, is 138 in length and its identities to human, murine, canine and bovine GM-CSFs are 63, 49, 63, and 63% respectively. The genomic DNA of woodchuck GM-CSF was also cloned by PCR. Its organization is highly homologous to that of human and murine GM-CSF genes, consisting of four exons and three introns. Cloned woodchuck GM-CSF was expressed transiently in 293T cells. The recombinant protein expressed was found to stimulate the growth and differentiation of woodchuck bone marrow cells, indicating the protein expressed by the cloned gene is functional. These results pave the way for future studies on the potential role of GM-CSF for the treatment of chronic hepatitis B by using this animal model.

Blockade of alpha1-adrenoceptors and cardiac depressant effect by a newly synthetic antihypertensive drug, DL-017 of quinazoline derivative

The electromechanical effects of 3-[[4-(2-methoxy phenyl)piperazin-1-yl]methyl]-5-(methylthio)-2,3-dihydroimidazo[1,2-c]quinazoline (DL-017), a newly synthesized quinazoline-derived antihypertensive agent, on mammalian cardiac tissues were evaluated. In driven canine Purkinje fibers, DL-017 decreased twitch tension, the maximal rate of upstroke of the action potential (Vmax), and intracellular Na+ activity (a(i)Na) in a concentration-dependent manner. The action potential duration was decreased in canine Purkinje fibers but increased in guinea pig papillary muscles. In guinea pig ventricular papillary muscles, phenylephrine in the presence of 1 microM propranolol increased the twitch tension in a concentration-dependent manner. At 10 microM, phenylephrine significantly decreased a(i)Na and shortened the action potential duration. DL-017 at 0.01 microM inhibited these phenylephrine-induced effects and shifted the concentration-dependent curve to the right. In sinoatrial nodes, DL-017 inhibited pacemaker activity, involving decreases in the slope of diastolic depolarization and Vmax and an increase in a delay of repolarization. These results suggest that, in addition to blockade of alpha1-adrenoceptors and Na+ channels, DL-017 reduces cardiac excitability and contractility in association with inhibition of slow inward Ca2+ and outward K+ channels. Since two order higher concentrations are required, the contribution of DL-017 to cardiac depressant from blockade of ionic channels seems to be less important when this compound is clinically used as an antihypertensive drug.

Existence of hepatitis C virus in Culex quinquefasciatus after ingestion of infected blood: experimental approach to evaluating transmission by mosquitoes

We used PCR to detect hepatitis C virus (HCV) RNA among supernatants of ground Culex quinquefasciatus mosquitoes that (i) had been fed HCV-positive blood, (ii) had been intrathoracically inoculated with HCV-positive blood, or (iii) were from homes of hepatitis C patients. HCV RNA was detectable under all three conditions, but it did not replicate in mosquitoes and was not detectably transmitted during feeding.

A novel platelet-rich arterial thrombosis model in rabbits. Simple, reproducible, and dynamic real-time measurement by using double-opposing inverted-sutures model

Though numerous animal thrombosis models have been introduced, an easy, reliable, and reproducible arterial thrombosis model remains a continuing challenge prior to a thrombolytic study. In an effort to evaluate the efficiency of various recombinant thrombolytic agents with specific affinity to activated platelets in vivo, we developed a novel double-opposing inverted-sutures model to create a platelet-rich thrombus in the femoral artery of rabbits. The arteriotomy was done semicircumferentially, and variously sized microsurgical sutures were introduced intraluminally in a double-opposing inverted manner. The animals were divided into three groups according to the double-opposing inverted-sutures used: Group 1 with 10-0 nylon (n=6), Group 2 with 9-0 nylon (n=6), and Group 3 with 8-0 nylon (n=22). The superficial epigastric branch was cannulated with a thin polyethylene (PE) tube for intraarterial administration of the studied thrombolytic agent. The blood flow was continuously measured with a real-time ultrasonic flow meter. Within 2 h of installation of the sutures, there was no thrombus formation in either Group 1 or 2. In Group 3, the thrombosis rate was 91% (20 of 22) under a steady baseline flow (with an average of 12.23+/-2.40 ml/min). It was highly statistically significant with a P-value of .0000743 using Fisher's Exact Test. The averaged time to thrombosis was 21.8+/-9.8 min. The ultrasonic flow meter to record the dynamic real-time measurement of blood flow was a guideline for thrombus formation or dissolution, which was correlated with the morphological findings of stenotic status of the vessel detected by the Doppler sonography. The components of the thrombus were proven to be platelet-rich predominant by histological examination via hematoxylin and eosin (H&E) stain and transmission electron microscopy (TEM). To confirm that the double-opposing inverted-sutures model would be useful for a study of thrombolytic agents, we evaluated the effects of recombinant tissue-type plasminogen activator (rt-PA) and streptokinase-human plasminogen (SK-HPlg). The average time to thrombolysis post rt-PA infusion was 16.0+/-8.2 min and that of SK-HPlg was 79.6+/-23.1, which were similar to the previous reports. In conclusion, the novel double-opposing inverted-sutures (8-0 nylon) model provides a simple, reliable, and reproducible platelet-rich arterial thrombosis model with noninvasive and dynamic real-time measurement. It may be applied in assessing the efficiency of the recombinant thrombolytic agents and offers many advantages of an arterial platelet-rich in vivo thrombosis model.