Urban-rural disparities in acceptance of human papillomavirus vaccination among women in Can Tho, Vietnam.

Background: In Vietnam, cervical cancer is a significant public health concern for women. Unfortunately, despite the availability of the HPV vaccine, low vaccination rates persist. Objectives: This study investigates the discrepancy between urban and rural areas in the willingness to receive HPV vaccination with or without fees. Methods: A cross-sectional study was conducted on a sample of 648 women aged between 15 and 49, living in two urban and two rural Vietnamese districts of Can Tho, between May and December 2021. Results: The overall vaccination rate was 4%, with urban women having a higher rate of 4.9% compared to rural women at 3.1%. Among unvaccinated women, those from rural areas expressed a significantly higher desire to receive the free vaccine (91.4%) than urban women (84.4%). However, the intention to vaccinate declined when rural women and urban women were advised to pay the cost (63.4% and 57.1%, respectively). A strong correlation was found between a positive attitude and intention for vaccination, irrespective of its price or free availability. Education and access to information about the HPV vaccine were also identified as the most significant factors influencing the intention to vaccination among urban and rural women. Conclusion: The low HPV vaccination rates among women aged 15-49 living in both urban and rural regions of Vietnam are a notable public health concern. These outcomes emphasize the critical need for effective programs of vaccine laterization, as an introduction to the offer of affordable and accessible HPV vaccines for women in Can Tho, Vietnam.

Cooperative improvement in growth rate, red-colour score and astaxanthin level of white-leg shrimp by Bacillus strains originating from shrimp gut.

AIMS: We investigated the potential cooperative effects of carotenoid-producing Bacillus aquimaris SH6 and nonpigmented Bacillus subtilis SH23 on white-leg shrimp growth and health. METHODS AND RESULTS: SH6, SH23 and a combination of both spores (1 × 106  CFU per g pellet) were administered in shrimp. The growth rate (2·36% day-1 ), red-colour score (25) and astaxanthin concentration (3·5 µg g-1 shrimp) were maximum in two-spore-administered shrimp. Immune-related Rho mRNA expression level and phenoloxidase and superoxidase dismutase activities were higher in two-spore-administered shrimp than in control shrimp, with Rho mRNA expression level being 55-fold higher in two-spore-administered shrimp than in SH6-administered shrimp and phenoloxidase activity being 1·2-fold higher in two-spore-administered shrimp than in SH23-administered shrimp. Although live SH6 count was 2·7-fold lower, SH6 germination level was 3·5-fold higher in the combination group than in SH6 group. CONCLUSIONS: When both SH6 and SH23 spores were administered, SH6 spore germination was enhanced and cooperative improvement was seen in growth, astaxanthin level and red-colour score of white-leg shrimp; however, immune-related parameters were induced in a noncooperative manner. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report showing the cooperative probiotic activities of Bacillus strains and their possible mechanisms in a shrimp model.

Protection of Penaeus monodon against white spot syndrome by continuous oral administration of a low concentration of Bacillus subtilis spores expressing the VP28 antigen.

In this study, Bacillus subtilis spores expressing a chimeric protein, CotB-VP28, were used as a probiotic vaccine to protect black tiger shrimps (Penaeus monodon) against white spot syndrome virus (WSSV) infection. Oral administration of pellets coated with CotB-VP28 spores (at ≥1 × 109  CFU per g pellet) to shrimps induced immune-relating phenoloxydase activity (PO) in shrimps after 14 days of feeding (prior challenge) and at day 3 post challenge (1·26 and 1·70 fold increase respectively). A 75% protection rate was obtained by continuous feeding of the spore-coated pellets at ≥1 × 109  CFU per g for 14 days prior to WSSV challenge and during all the postchallenge period. Even when the amount of CotB-VP28 spores in feed pellets was reduced down to ≥5 × 107  CFU per g and ≥1 × 106  CFU per g, relatively high protection rates of 70 and 67·5%, respectively, were still obtained. By contrast, feeding pellets without spores (untreated group) and with naked spores (PY79 group) at ≥1 × 109  CFU per g could not protect shrimps against WSSV. These data suggest that supplementation of CotB-VP28 spores at low dose of ≥1 × 106  CFU per g could be effective as a prophylactic treatment of WSS for black tiger shrimps. SIGNIFICANCE AND IMPACT OF THE STUDY: This study reports the protective efficacy of Bacillus subtilis CotB-VP28 spores on black tiger shrimps (Penaeus monodon) against white spot syndrome virus infection. Oral administration of pellets coated with CotB-VP28 spores (≥1 × 109  CFU per g) conferred 75% protection after white spot syndrome virus challenge. Even after reducing CotB-VP28 spores in feed pellets to ≥1 × 106  CFU per g, 67·5% protections was still obtained. These data indicate that supplementation of CotB-VP28 spores at a low dose of ≥1 × 106  CFU per g could be effective in prophylaxis against white spot syndrome in black tiger shrimps.

Screening of pigmented Bacillus aquimaris SH6 from the intestinal tracts of shrimp to develop a novel feed supplement for shrimp.

AIMS: To develop a novel feed supplement for shrimp using pigmented spore-forming bacterial strains isolated from their gastrointestinal tracts. METHODS AND RESULTS: Eight pigmented Bacillus strains were selected from the isolates based on high production of heat-stable spores, typical UV-Vis spectra of produced carotenoids (400-550 nm), and free radical scavenging activity of their extracts. Of the eight strains, the red-orange pigmented Bacillus aquimaris SH6 was selected because it showed the highest abundance in shrimp guts (70% population). Whiteleg shrimp (n = 30 per group) fed with SH6 spores, at >3 × 106  CFU g-1  pellet for 4 weeks had redder colour (score of 21-23 vs 20-22), 2·7-fold higher astaxanthin level (0·69 vs 0·25 µg g-1 shrimp), 34% higher weight gain (7·18 vs 5·32 g shrimp-1 ), and 85% higher phenoloxidase activity (OD490  = 0·265 vs 0·143) than shrimp in the control group. CONCLUSIONS: The result supports the potential use of B. aquimaris SH6 as a feed supplement for promoting the colourization and weight gain, and for enhancing innate immunity of whiteleg shrimp. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates that carotenoids produced by B. aquimaris SH6 can be successfully absorbed and converted to astaxanthin in whiteleg shrimp.

Isolation and characterization of Bacillus subtilis CH16 strain from chicken gastrointestinal tracts for use as a feed supplement to promote weight gain in broilers.

Spore-forming bacterial strains were isolated from chicken gastrointestinal tracts to develop a heat-stable feed supplement that promotes weight gain in broilers. Seven Bacillus strains having more than 90% sporulation were screened from the isolates and identified to be closely related with Bacillus subtilis and Bacillus licheniformis. Of the seven strains, B. subtilis CH16 was selected to develop a feed supplement for broilers, because it formed 100% heat-stable spores, grew rapidly at 42°C and quickly formed a biofilm. In large-scale trials in broilers (n ≥ 1150 per group), the group fed CH16 (3 × 10(6) CFU g(-1) pellet) showed higher average daily gain (ADG = 61·16) and lower food conversion ratio (FCR = 1·696) than did the group fed B. licheniformis CH22 (ADG = 57·10 and FCR = 1·792), the group fed B. subtilis HU58 (ADG = 51·90 and FCR = 1·868), BioPlus group (ADG = 59·32 and FCR = 1·807) and the control group (ADG = 56·02 and FCR = 1·880). In conclusion, CH16 spores significantly increased ADG by 9·17% and reduced FCR by 9·79% in broilers. The result supports the use of B. subtilis CH16 of chicken intestinal origin as a feed supplement that promote weight gain in broilers. Significance and impact of the study: This study reports screening of Bacillus strains isolated from chicken gastrointestinal tracts for development of a feed supplement that promote weight gain in broilers. Of the seven Bacillus isolates with high sporulation efficiency (≥90%), Bacillus subtilis CH16 strain showed the best growth and biofilm formation at body temperature of broilers (42°C). In large-scale trials in broilers (n ≥ 1150 per group), CH16 spores induced a 9·17% increase in daily weight gain (ADG) and a 9·79% reduction in FCR while the commercial BioPlus(®) YC induced only a 5·89% increase in ADG and a 3·88% reduction in FCR.

Effect of interfaces on the melting of PEO confined in triblock PS-b-PEO-b-PS copolymers.

Block copolymers form nanostructures that have interesting physical properties because they combine, for a single compound, the complementary features brought by each block. However, in order to fully exploit these properties, the physical state of each kind of domain must be precisely controlled. In this work, triblock PS-b-PEO-b-PS copolymers consisting of a central poly(ethylene oxide) (PEO) block covalently bonded to polystyrene (PS) blocks were synthesized by Atom Transfer Radical Polymerization. Their morphology was investigated by X-ray scattering and TEM experiments whereas their thermodynamic behavior was characterized by DSC. A strong decrease of both the melting temperature and the degree of crystallinity of PEO, due to its confinement between the PS domains, was observed and analyzed with a modified Gibbs-Thomson equation, following the approaches used for fluids confined in porous media. The existence of an amorphous bound layer, a few nanometers thick, at the PEO/PS interface, that does not undergo any phase transition in the temperature range investigated, accounts for both the melting temperature depression and the decrease of crystallinity upon confinement. This interfacial layer may significantly affect the mechanical and transport properties of these block copolymers that find applications as solid polymer electrolytes in batteries for example. Moreover, the value obtained for the solid PEO/liquid PEO surface tension is lower than those previously published but is thermodynamically consistent with the surface tensions of polymers at the solid/vapor and liquid/vapor interfaces.

Comparison of three methods of diagnosis of plasma unmeasured anions in critically ill patients.

BACKGROUND: The measurement of plasma unmeasured anions (PUA) is paramount in assessing metabolic acid base disorders. The aim of this study was to compare the accuracy of three methods in diagnosing abnormal PUA values: standard base excess (SBE), the albumin corrected anion gap (AGc), and the Stewart-Figge approach, based on unidentified anions (XAc-). METHODS: Acid-base variables were prospectively collected in ICU patients admitted January-September 2008. Whatever the method, PUA values measured two standard deviations above or below the mean of those in control subjects were considered as abnormal. RESULTS: Of the 205 consecutives patients included, 179 had an abnormal PUA value. The accuracy of AGc and XAc- in diagnosing abnormal PUA values was comparable (AUC: 0.89±0.03 and 0.89±0.03, P=0.82) but greater than that of SBE (0.67±0.06, P<0.001 and P<0.001, respectively). Of the high PUA values (n=161), 96% were diagnosed by XAc-, 88% by AGc (P<0.01) and 48% by SBE (P<0.001). Hyperlactatemia (n=111) was diagnosed equally by AGc and XAc-, (81% and 86%, P=0.37) but less by SBE (50%, P<0.001 and P<0.001, respectively). High PUA not associated with hyperlactatemia (N.=61) was more frequently diagnosed by XAc- (97%) than by AGc (84%, P=0.03). CONCLUSION: In ICU patients, AGc and the Stewart-Figge approach should be preferred over SBE for diagnosing abnormal PUA values and predicting hyperlactatemia. The Stewart-Figge approach based on unidentified anions, is the most efficient in diagnosing high PUA values not associated with hyperlactatemia.

A specific and sensitive antigen capture assay for NS1 protein quantitation in Japanese encephalitis virus infection.

Japanese encephalitis virus (JEV) is a human pathogenic, mosquito-borne flavivirus that is endemic/epidemic in Asia. JEV is rarely detected or isolated from blood or cerebrospinal fluid (CSF), and detection of IgM is generally diagnostic of the infection. The flavivirus nonstructural glycoprotein NS1 is released transiently during flavivirus replication. The aim of this study was to set up a quantitative JEV NS1 antigen capture assay. A soluble hexameric form of JEV NS1 protein was produced in a stable Drosophila S2 cell clone and purified from supernatant fluids. Two IgG1 monoclonal antibodies (MAbs) with high affinity against two different epitopes of JEV NS1 antigen were used to develop an antigen-capture assay with a limit of detection of 0.2ngml(-1) NS1. Up to 1µgml(-1) JEV NS1 protein was released in supernatants of mammalian cells infected with JEV but <10ngml(-1) was released in sera of virus-infected mice before the onset of encephalitis and death. Moreover, NS1 protein was detected at low levels (<10ngml(-1)) in 23.8% of sera and in 10.5% of CSF of patients diagnosed as IgM-positive for JEV. This quantitative test of NS1 protein is proposed for highly specific diagnosis of acute infection with JEV genotypes I to IV.

Adsorption mechanism and dispersion efficiency of three anionic additives [poly(acrylic acid), poly(styrene sulfonate) and HEDP] on zinc oxide.

Adsorption on ZnO of sodium poly(acrylate) (PAA), sodium poly(styrene sulfonate) (PSS) and a monomer surfactant [hydroxyethylidene diphosphonate (HEDP)] was investigated in suspensions initially equilibrated at pH 7. Results demonstrate interplay in the adsorption mechanism between zinc complexation, salt precipitation, and ZnO dissolution. In the case of PAA, the adsorption isotherm exhibits a maximum attributed to the precipitation of zinc polyacrylate. PSS and HEDP formed high-affinity adsorption isotherms, but the plateau adsorption of HEDP was significantly lower than that of PSS. The adsorption isotherm of each additive is divided into two areas. At low additive concentration (high zinc/additive ratio), the total zinc concentration in the solution decreased and the pH increased upon addition. At a higher additive ratio, zinc concentration and pH increased with the organic concentration. The increase in pH is due to the displacement of hydroxyl ions from the surface and the increase in zinc concentration results from the dissolution of ZnO due to the complexation of zinc ions by the organics. The stability of the ZnO dispersions was investigated by measurement of the particle size distribution after addition of various amounts of polymers. The three additives stabilized the ZnO dispersions efficiently once full surface coverage was reached.

Distribution of molar mass and branching index of natural rubber from Hevea brasiliensis trees of different age by size exclusion chromatography coupled with online viscometry.

Natural rubber from hevea brasiliensis trees (Thailand, RRIM 600 clone) of different age (8, 20, and 35 years) were characterized by size exclusion chromatography coupled with online viscometry according to their distribution of molar mass and branching index at a temperature of 70 degrees C using cyclohexane as solvent. Washing with an aqueous solution of sodium dodecylsulfate and subsequent saponification purified the natural rubber samples. With this procedure physical branching points caused by phospholipids, proteins and hydrophobic terminal units, mainly fatty acids, of the natural rubber (cis-1,4-polyisoprene) molecule, could be removed leading to completely soluble polymer samples. All samples investigated possess a very broad (10 to 50,000 kg/mol) and distinct bimodal molar mass distribution. With increasing age the peak area in the low molar mass region decreases favoring the peak area in the high molar mass region. By plotting the branching index as a function of the both, the molar mass and the age of the trees.

Physiologic actions of zinc related to inhibition of acid and alkali production by oral streptococci in suspensions and biofilms.

Zinc is a known inhibitor of acid production by mutans streptococci. Our primary objective was to extend current knowledge of the physiologic bases for this inhibition and also for zinc inhibition of alkali production by Streptococcus rattus FA-1 and Streptococcus salivarius ATCC 13419. Zinc at concentrations as low as 0.01-0.1 mm not only inhibited acid production by cells of Streptococcus mutans GS-5 in suspensions or in biofilms but also sensitized glycolysis by intact cells to acidification. Zinc reversibly inhibited the F-ATPase of permeabilized cells of S. mutans with a 50% inhibitory concentration of about 1 mm for cells in suspensions. Zinc reversibly inhibited the phosphoenolpyruvate: sugar phosphotransferase system with 50% inhibition at about 0.3 mm ZnSO4, or about half that concentration when the zinc-citrate chelate was used. The reversibility of these inhibitory actions of zinc correlates with findings that it is mainly bacteriostatic rather than bactericidal. Zinc inhibited alkali production from arginine or urea and was a potent enzyme inhibitor for arginine deiminase of S. rattus FA-1 and for urease of S. salivarius. In addition, zinc citrate at high levels of 10-20 mm was weakly bactericidal.

Fluoride and organic weak acids as respiration inhibitors for oral streptococci in acidified environments.

Oxygen metabolism (respiration) of Streptococcus mutans GS-5 involving NADH oxidases, mainly of the H(2)O-producing type, was found to be acid sensitive, as was NADH oxidase activity of cell extracts. Respiration of intact cells in acidified media was also highly sensitive to fluoride, with a 50% inhibitory concentration of about 0.02 mM at pH 4. In contrast, NADH oxidases in cell extracts were fluoride insensitive. Fluoride inhibition of respiration of intact cells was related to weak-acid effects leading to enhanced proton permeability of cells, cytoplasmic acidification and resultant acid inhibition of NADH oxidases and glycolysis. Organic weak acids, such as indomethacin and benzoate, were also effective inhibitors. H(2)O(2) production by intact cells of Streptococcus sanguis NCTC 10904, a peroxide producer, was similarly inhibited by fluoride or organic weak acids in acidified media. Thus, weak acids act as respiratory inhibitors for oral streptococci indirectly by acidifying the cytoplasm rather than acting as direct inhibitors of NADH oxidases.

Selective sensitization of bacteria to peroxide damage associated with fluoride inhibition of catalase and pseudocatalase.

Fluoride and sulfide are known inhibitors of heme catalases in acid environments. Staphylococcus aureus H cells were found to be sensitized by fluoride or sulfide to H2O2 killing at acid pH values in the range of 3.5 to 4.0, and catalase activity was reduced concomitantly. In contrast, fluoride had little effect on H2O2 killing of Streptococcus mutans GS-5, which has fluoride-insensitive peroxidase activity, but still is more sensitive to H2O2 than is S. aureus in the absence of fluoride. Fluoride but not sulfide was inhibitory also for the Mn-containing, non-heme pseudocatalase of Lactobacillus plantarum ATCC 14431 over a wide pH range, and this inhibitory effect was reflected in enhanced H2O2 killing in the presence of fluoride. In addition, we found that catalase-positive S. aureus or Neisseria sicca could protect catalase-negative S. mutans against killing by H2O2 in mixed suspensions, but protection was compromised by fluoride or sulfide under acid conditions. Thus, catalase-positive organisms could protect a catalase-negative organism against peroxide damage, but inhibition of catalase reduced protection. These findings are pertinent to the widespread use of fluoride and peroxide in oral health care products.

Sensitization of Actinomyces naeslundii and Streptococcus sanguis in biofilms and suspensions to acid damage by fluoride and other weak acids.

Fluoride and other weak acids, such as benzoate, indomethacin, salicylate and sorbate, were found to be sensitizers for acid killing of cells of Actinomyces naeslundii ATCC 19246 and Streptococcus sanguis NCTC 10904 in suspensions or in mono-organism biofilms on glass slides. These bacteria are among the more acid-sensitive organisms from dental plaque and were killed when acidified to pH values between 3.5 and 4.0. Biofilm cells were more resistant than cells in suspensions, especially in terms of the fraction of the initial population surviving acidification. The mechanism for sensitization to acid killing by fluoride and the other weak acids involved enhanced transmembrane transport of protons, reflected by increases in measured proton permeabilities of the cells. Thus, the weak acids thwarted the functions of F(H+)-ATPases in extruding protons and protecting cells against acid damage. Fluoride sensitization of biofilms or cells in suspensions to acid damage occurred rapidly. There was a delay in sensitization of biofilms by indomethacin and higher molecular weight acids which was interpreted in terms of diffusion limitation of sensitizer penetration. Overall, it seemed that weak-acid sensitization to acid killing is a general phenomenon that occurs not just for oral bacteria but also for organisms in food, soil, and other acidified environments.

Calnexin from Pisum sativum: cloning of the cDNA and characterization of the encoded protein.

A full-length cDNA of 1951 bp encoding a calnexin (CNX) protein was cloned from a Pisum sativum expression library. The open reading frame (ORF) within this cDNA encodes a 551-amino acid protein with a calculated molecular mass of 62.47 kDa that exhibits extensive homology with the CNX proteins from soybean (80%), Arabidopsis thaliana (70%), maize (70%), and dog (39%). The characteristic CNX signature motifs, KPEDWDE and GXW, generally found in molecular chaperones, are present in pea CNX (PsCNX), along with putative sites for Ca2+ binding and phosphorylation. In PsCNX, a signal sequence and a single transmembrane domain are also present at the N- and C-terminal ends, respectively. The PsCNX protein is expressed constitutively at the RNA level in vegetative and flowering tissues, as was evident from Northern analysis. Expression of PsCNX was light independent. In vitro translation of PsCNX cDNA yielded a 75-kDa precursor, which, in the presence of canine microsomal membranes, was cotranslationally processed into a 72.5-kDa product and was imported and localized to the endoplasmic reticulum. Trypsin treatment of the in vitro translated PsCNX in the presence of canine microsomes generated a further processed 67-kDa intraluminal form. The results with PsCNX also showed that the plant protein is a phosphoprotein containing phosphoserine residues, as evidenced by immunoprecipitation of PsCNX with anti-phosphoserine antibody. The PsCNX protein was also phosphorylated by endogenous kinases of pea microsomes.

Inhibition of pea chloroplast DNA helicase unwinding and ATPase activities by DNA-interacting ligands.

DNA helicases unwind the duplex DNA in an ATP dependent manner and thus play an essential role in DNA replication, repair, recombination and transcription. Any DNA-interacting ligand which will modulate DNA helicase activity may interrupt practically all kinds of DNA transactions. There are no studies on the effect of various cytotoxic DNA-interacting ligands on organelle helicases. We have determined the effect of camptothecin, VP-16 (etoposide), ellipticine, genistein, novobiocin, m-AMSA, actinomycin C1, ethidium bromide, daunorubicin and nogalamycin on unwinding and ATPase activities of purified chloroplast DNA helicase from pea (Pisum sativum). Our study has shown that DNA-intercalating ligands actinomycin C1, ethidium bromide, daunorubicin and nogalamycin were inhibiting the DNA unwinding activity with an apparent Ki of 2.9 microM, 3.0 microM, 1.4 microM and 1.0 microM, respectively. These four inhibitors also inhibited the ATPase activity of pea chloroplast DNA helicase. These results indicate that the intercalation of the inhibitors into DNA generates a complex that impedes the translocation of chloroplast DNA helicase, resulting in both inhibition of unwinding activity and ATP hydrolysis. This study would be useful for understanding the mechanism of organelle DNA helicase unwinding and the mechanism by which these DNA-interacting ligands inhibit cellular function.

Inhibition of DNA unwinding and ATPase activities of human DNA helicase II by chemotherapeutic agents.

DNA helicases catalyze the unwinding of duplex DNA and thus play important roles in the processing of DNA, little is known about the effects of various cytotoxic or antitumor chemotherapeutic agents on purified human DNA helicases. We have determined the effect of actinomycin C1, VP-16, camptothecin, ethidium bromide, ellipticine, nogalamycin, novobiocin, genistein, m-AMSA, aphidicolin and daunorubicin on the enzymatic activities of purified human DNA helicase II which was identified as Ku autoantigen. Ku contains DNA helicase, ATPase and DNA end binding activities. Our data have shown that out of several chemotherapeutic agents tested ethidium bromide, actinomycin C1, daunorubicin and nogalamycin were inhibitors of DNA unwinding activity of human DNA helicase II with ID50 values of 8.44 microM, 11.68 microM, 6.23 microM and 0.42 microM respectively. These inhibitors also inhibited the ATPase activity but not the DNA binding activity of this helicase. This inhibition could be due to binding of these drugs to DNA, thereby impeding the movement of the helicase for unwinding action which may be their most important pharmacological function against cancer cells.

Purification and characterization of a DNA helicase from pea chloroplast that translocates in the 3'-to-5' direction.

An ATP-dependent DNA helicase has been purified to near homogeneity from pea chloroplasts. The enzyme is a homodimer of 68-kDa subunits. The purified enzyme shows DNA-dependent ATPase activity and is devoid of DNA polymerase, DNA topoisomerase, DNA ligase or nuclease activities. The enzyme requires Mg2+ or Mn2+ for its maximum activity. ATP is the most favoured cofactor for this enzyme while other NTP or dNTP are poorly utilized. Pea chloroplast DNA helicase can unwind a 17-bp duplex whether it has unpaired single-stranded tails at both the 5' end and 3' end, at the 5' end or at the 3' end only, or at neither end. However, it fails to act on a blunt-ended 17-bp duplex DNA. The enzyme moves unidirectionally from 3' to 5' along the bound strand. The unwinding activity is inhibited by the intercalating drugs nogalamycin and daunorubicine.