Cryopreservation of adult bovine testicular tissue for spermatogonia enrichment

To develop a procedure for cryopreservation of adult bovine testis tissue, the effects of dimethyl sulphoxide (DMSO), propylene glycol (PG), ethylene glycol (EG), and their concentrations (v/v), as well as different thawing temperatures, on the cell viability of bovine testis tissue after freezing/thawing were examined. The highest testicular cell viabilities came from the media containing DMSO (85.3 ± 1.2 percent), PG (82 ± 1.0 percent) and EG (83.4 ± 1.0 percent) at 10 percent concentration respectively. Using 10 percent DMSO gave significantly higher spermatogonia percentage (61.1 ± 1.2 percent, P < 0.001) than processing with 10 percent PG (54.3 ± 0.6 percent) or 10 percent EG (55 ± 1.8 percent) after differential plating. Thawing in water bath of 37 or 97-100 degree C also provided significantly higher viabilities (85.1 ± 1.0, 85 ± 1.0 percent, P < 0.01, respectively) and spermatogonia percentages (56.6 ± 2.0, 56.6 ± 2.6 percent, P < 0.01, respectively) than that thawing at 4C (23.4 ± 0.8 percent for total viability, 8.97 ± 1.0 percent for spermatogonia percentage). Collectively, 10 percent DMSO and thawing in 37-100 degree C water baths were appropriate for the cryopreservation of bovine testicular tissue and subsequent spermatogonia enrichment.

Facile microwave-combustion synthesis of wurtzite CdS nanoparticles

In this study we first report microwave-combustion synthesis of faceted CdS nanoparticles by using cadmium thiocyanate complex as a single source precursor. This is the first example of a metal-thiocyanate (M-SCN) complex being used as a source for metal sulfides (M-S) preparation in a microwave-combustion process. The synthesized CdS was characterized using X-ray diffraction (XRD), field mission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM). The by-product assisted combustion synthesis yields CdS nanoparticles with the mixtures of octahedral geometries, hexagonal, and triangle plate morphologies and the sizes were found to be 100 nm to 5 microm. The XRD patterns imply the formation of well crystallized wurtzite CdS. The influence of cadmium and sulfur precursors and microwave irradiation time on the morphology of CdS nanoparticle was also investigated. The cadmium and sulfur precursors strongly influenced the CdS morphology and increasing the microwave irradiation time and intensity has no effect on the CdS morphology. In addition, a plausible mechanism of CdS nanoparticle formation has been proposed in this research.

Wear and surface analysis of 38 mm ceramic-on-metal total hip replacements under standard and severe wear testing conditions

The purpose of this study was to compare the wear of zirconia-toughened alumina (ZTA) and alumina femoral heads tested against as-cast CoCrMo alloy acetabular cups under both standard and severe wear conditions. A new severe test, which included medio-lateral displacement of the head and rim impact upon relocation, was developed. This resulted in an area of metal transfer and an area of increased wear on the superior-anterior segment of the head that were thought to be due to dislocation and rim impact respectively. While the wear of all ceramic heads was immeasurable using the gravimetric method, the wear rates for the metallic cups from each test were readily calculated. An average steady state wear rate of 0.023 ± 0.005 mm3/106 cycles was found for the cups articulating against ZTA under standard wear conditions. A similar result had previously been obtained for the wear of cups articulated against alumina heads of the same size (within the same laboratory). Under severe wear conditions an increase in the metallic cup steady state wear rate was found with the ZTA and alumina tests giving 0.623 ± 0.252 and 1.35 ± 0.154 mm3/106 cycles respectively. Wear of the ceramic heads was detected using atomic force microscopy which showed, under severe wear conditions, a decrease in polishing marks and occasional grain removal. The surfaces of the ZTA heads tested under standard conditions were virtually unchanged from the unworn samples. Friction tests showed low friction factors for all components, pre and post wear.

Trihalomethanes and haloacetic acid species from the chlorination of algal organic matter and bromide

Bromide and algal pollution are important factors influencing disinfection byproduct (DBP) formation and speciation in reservoir water in coastal areas. In this study, the chlorination of model algal cellular compounds (bovine serum albumin, fish oil and starch), Microcystis aeruginosa and its extra-cellular organic matter (EOM) were conducted in the absence and presence of bromide. The main aim of the present study is to explore their potential as precursors for trihalomethanes (THMs) and haloacetic acid (HAAs) speciation upon chlorination in the presence of bromide. The results showed that all brominated THMs species were generated, whereas only bromochloroacetic acid (BCAA) or/and dibromoacetic acid (DBAA) was/were produced as for brominated HAAs (Br-HAAs) from the three model compounds in the presence of bromide. The effect of bromide on Br-HAAs speciation upon fish oil chlorination was more evident than with BSA and starch. There was a good correlation between the species predicted from the model compounds and those obtained from specific algal species. Br-HAAs and Br-THMs species from Microcystis aeruginosa cells or EOM were the same as those from bovine serum albumin in the presence of bromide.

Prevalence and characteristics of ertapenem-nonsusceptible Escherichia coli in a Taiwanese university hospital, 1999 to 2007

The present study was conducted to investigate the prevalence and characteristics of ertapenem-nonsusceptible (ETP-NS) Escherichia coli in a Taiwanese university. A total of 9,722 isolates collected in 1999, 2003, 2005, and 2007 were examined. Overall, 1.0% of all isolates from 66 patients were interpreted as ETP-NS on the basis of the disk diffusion test result. Most of these isolates were clonally unrelated and showed low-level ertapenem resistance, the production of CMY-2 cephalosporinase (86.4%), and decreased expression of the OmpF (97.0%) and/or OmpC (56.1%) porins. No carbapenemase was detected. The decreased porin expression was associated with disruptions of ompF or ompC in only about one-third of the ETP-NS isolates. During the study period, the prevalence of ETP-NS strains increased from 0.1 to 1.7%, accompanying an increase (0.8 to 17.6%) in the prevalence of CMY-2 producers. Coexistent or pre-existing clonally related ertapenem-susceptible (ETP-S) E. coli isolates were identified in 47.0% of all case patients, and almost all of the ETP-S isolates had the same β-lactamases as the ETP-NS isolates. Our study results suggest the restricted use of extended-spectrum cephalosporins to hinder the emergence and prevalence of carbapenem resistance in E. coli, which may arise by the accumulation of multiple resistance determinants.

Application of low-volume zero-balanced ultrafiltration and its effect on blood propofol concentration: a randomized controlled trial

AIM

The aim of this study was to evaluate the effectiveness of low-volume zero-balanced ultrafiltration during cardiopulmonary bypass in heart valve replacement surgery.

METHODS

This was a randomized, double-blind, controlled study carried out in the operating room. Forty patients of ASA grade II-III, elected to undergo heart valve replacement surgery, were enrolled. All patients were randomly assigned to either a low-volume (35 mL/kg) zero-balanced ultrafiltration group (N.=20) or to a control group (N.=20). Blood propofol concentrations and entropy index were measured using cardiopulmonary bypass. Concentrations of plasma tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-10 (IL-10), and cardiac troponin I were measured before and after the end of cardiopulmonary bypass and corrected according to hematocrit.

RESULTS

Blood levels of cardiac troponin I, TNF-alpha, IL-6, and IL-10 after surgery were all significantly lower in the ultrafiltration group than in the control group (P<0.05) after the end of bypass. Blood propofol concentrations decreased significantly in both groups during cardiopulmonary bypass and remained significantly lower in the ultrafiltration group than the control group. However, there was no significant difference between the two groups in the entropy index (P=0.5583).

CONCLUSION

Low-volume zero-balanced ultrafiltration performed during cardiopulmonary bypass surgery significantly decreased post-bypass levels of the cytokines, TNF-alpha, IL-6, IL-10, and postoperative cardiac troponin I. Blood propofol concentration was also decreased; however, the depth of anesthesia was not affected significantly.

Human lactoferrin stimulates skin keratinocyte function and wound re-epithelialization

BACKGROUND

Human lactoferrin (hLF), a member of the transferrin family, is known for its antimicrobial and anti-inflammatory effects. Recent studies on various nonskin cell lines indicate that hLF may have a stimulatory effect on cell proliferation.

OBJECTIVES

To study the potential role of hLF in wound re-epithelialization.

MATERIALS AND METHODS

The effects of hLF on cell growth, migration, attachment and survival were assessed, with a rice-derived recombinant hLF (holo-rhLF), using proliferation analysis, scratch migration assay, calcein-AM/propidium iodide staining and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) method, respectively. The mechanisms of hLF on cell proliferation and migration were explored using specific pathway inhibitors. The involvement of lactoferrin receptor low-density lipoprotein receptor-related protein 1 (LRP1) was examined with RNA interference technique. An in vivo swine second-degree burn wound model was also used to assess wound re-epithelialization.

RESULTS

Studies revealed that holo-rhLF significantly stimulated keratinocyte proliferation which could be blocked by mitogen-activated protein kinase (MAPK) kinase 1 inhibitor. Holo-rhLF also showed strong promoting effects on keratinocyte migration, which could be blocked by either inhibition of the MAPK, Src and Rho/ROCK pathways, or downregulation of the LRP1 receptor. With cells under starving or 12-O-tetradecanoylphorbol-13-acetate exposure, the addition of holo-rhLF was found greatly to increase cell viability and inhibit cell apoptosis. Additionally, holo-rhLF significantly increased the rate of wound re-epithelialization in swine second-degree burn wounds.

CONCLUSIONS

Our studies demonstrate the direct effects of holo-rhLF on wound re-epithelialization including the enhancement of keratinocyte proliferation and migration as well as the protection of cells from apoptosis. The data strongly indicate its potential therapeutic applications in wound healing.

Nanoparticles targeted with NGR motif deliver c-myc siRNA and doxorubicin for anticancer therapy

We have designed a PEGylated LPD (liposome-polycation-DNA) nanoparticle for systemic, specific, and efficient delivery of small interfering RNA (siRNA) into solid tumors in mice by modification with NGR (aspargine-glycine-arginine) peptide, targeting aminopeptidase N (CD13) expressed in the tumor cells or tumor vascular endothelium. LPD-PEG-NGR efficiently delivered siRNA to the cytoplasm and downregulated the target gene in the HT-1080 cells but not CD13(-) HT-29 cells, whereas nanoparticles containing a control peptide, LPD-PEG-ARA, showed only little siRNA uptake and gene silencing activity. LPD-PEG-NGR efficiently delivered siRNA into the cytoplasm of HT-1080 xenograft tumor 4 hours after intravenous injection. Three daily injections (1.2 mg/kg) of c-myc siRNA formulated in the LPD-PEG-NGR effectively suppressed c-myc expression and triggered cellular apoptosis in the tumor, resulting in a partial tumor growth inhibition. When doxorubicin (DOX) and siRNA were co-formulated in LPD-PEG-NGR, an enhanced therapeutic effect was observed.

Effect of temperature on the formation of macroporous ZnO bundles and its application in photocatalysis

In this article, the effects of temperature on the formation of macroporous zinc oxide bundles and its photocatalytic activity under a variety of experimental conditions were reported. Thermal decomposition of zinc oxalate dihydrate yields hexagonal wurtzite-type ZnO bundles. Increased the decomposition temperatures resulted in decreased time required for bundle formation, with a corresponding increase in nanoparticles agglomeration. ZnO bundle formation was facilitated up to 200 degrees C after complete decomposition of zinc oxalate into ZnO at 400 degrees C in 15 min. However, low temperature (such as 100 degrees C) was not facilitated nanobundle formation, suggesting the importance of temperature on ZnO bundles formation. In addition, nitrogen adsorption experiments confirmed the presence of macroporous structure in the bundles. The photocatalytic decolorization and adsorption of methylene blue dye (MB) on ZnO bundles were investigated under UV light irradiation. The adsorption and decolorization efficiency of macroporous bundles were higher than the fused bundles. In conclusion, ZnO bundles are efficient and easily recyclable photocatalyst.

Tribological and surface analysis of 38mm alumina–as-cast Co–Cr–Mo total hip arthroplasties

There is currently much discussion over the use of ceramic femoral components against metal acetabular cups, for use in total hip arthroplasty. The current study investigates six hot isostatically pressed alumina femoral heads of 38 mm diameter articulating against six as-cast Co—Cr—Mo metallic acetabular cups. Standard walking-cycle simulator wear testing was carried out to 5×106 cycles using the Durham Mark II hip wear simulator, and wear was determined gravimetrically. In addition, surface topography, using a non-contacting profilometer, an atomic force microscope, and an optical microscope, was monitored throughout the wear test. The wear of the ceramic heads was found to be undetectable using the current gravimetric method; however, a change in the surface topography was seen, as grain removal on the pole was observed through atomic force microscopy analysis. A biphasic wear pattern was found for the metallic cups, with low wear rates of 1.04 ± 0.293 mm3/106 cycles (mean, ±95 per cent confidence interval) and 0.0209 ± 0.004 mm3/106 cycles (mean, ±95 per cent confidence interval) for running-in and steady state wear phases respectively. Frictional measurement revealed that the joints were tending towards full fluid-film lubrication in parts of the walking cycle. The results show that the combination of hot isostatically pressed alumina and as-cast Co—Cr—Mo is a promising alternative for total hip arthroplasties.

Evaluation of the capability of the VITEK 2 system to detect extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae isolates, in particular with the coproduction of AmpC enzymes

A total of 317 Klebsiella pneumoniae and 291 Escherichia coli nonduplicate isolates were tested by the VITEK 2 system to evaluate its capability to detect extended-spectrum beta-lactamases (ESBLs) among putative ESBL-producing isolates, in particular those with the coproduction of AmpC enzymes. beta-lactamases produced by the test isolates had been characterised. The sensitivity and specificity for ESBLs were 98.9% and 98.5%, respectively. Ninety of the isolates were AmpC (CMY-2, CMY-8 or DHA-1) and ESBL (SHV and/or CTX-M) coproducers, and 74 isolates (82.2%) of them were flagged as ESBL producers. Our study indicates that the VITEK 2 system is an acceptable tool for ESBL detection among K. pneumoniae and E. coli isolates for laboratories where both imported AmpC and ESBLs are prevalent.

Kinetic distribution of 14C-metsulfuron-methyl residues in paddy soils under different moisture conditions

Rice paddy soils undergo several cycles of drying and wetting during a growing season. A laboratory study was conducted to determine the effect of soil moisture conditions on the distribution and kinetics of extractable and bound residues of 14C-metsulfuron-methyl in six Chinese paddy soils during 84 d of incubation at 15 degrees C with moisture contents varying from 20 to 50% of the field water-holding capacity. The amount of extractable residues consistently increased and bound residues decreased with increasing soil moisture content. At the end of the incubation experiments, extractable residues and bound residues accounted for 34.5 to 84.4% and 11.6 to 53.3% of applied radioactivity in soils, respectively. Soil pH and soil microbial biomass carbon were the most predominant factors affecting the formation and relative distribution of herbicide residues between extractable and bound residue forms. In high-pH soils, bound residues decreased and extractable residues increased, suggesting an increased leaching risk for metsulfuron-methyl in alkaline soils. High precipitation rates, along with the common practice of liming in southeastern China, may lead to enhanced herbicide leaching as well as phytotoxicity to rotation plants and should be considered in overall pest management practices.

Sex ratio bias in early-dead embryos of chickens collected during the first week of incubation

According to Mendelian heredity laws, the sex ratio of a given chicken population during hatching is expected to be 1:1. In this study, we collected 432 chicken embryos that died during the first week of incubation from 5 different breeds. The sexes of the early-dead embryos were determined by using the previously described molecular sexing technique of double PCR. The female-to-male sex ratio was analyzed for departure from the expected 1:1 sex ratio by chi(2) testing. These results showed that the number of female dead embryos was significantly greater than that of males in the Hubei local breeding stock, Zhusi, and Hy-line Variety Brown (P < 0.05, P < 0.01, P < 0.01 respectively), with observed female-to-male sex ratios of 1.40:1, 2.03:1, and 2.22:1, respectively. Two other Chinese local breeds (the Yellow chicken and the Aijiaohuang chicken) also showed altered sex ratios, although the differences were not significant. Altogether, these results indicated that female chickens were more likely than male chickens to die at the early stages of incubation.

PL-100, a novel HIV-1 protease inhibitor displaying a high genetic barrier to resistance: an in vitro selection study

The development of new HIV inhibitors with distinct resistance profiles is essential in order to combat the development of multi-resistant viral strains. A drug discovery program based on the identification of compounds that are active against drug-resistant viruses has produced PL-100, a novel potent protease inhibitor (PI) that incorporates a lysine-based scaffold. A selection for resistance against PL-100 in cord blood mononuclear cells was performed, using the laboratory-adapted IIIb strain of HIV-1, and it was shown that resistance appears to develop slower against this compound than against amprenavir, which was studied as a control. Four mutations in protease (PR) were selected after 25 weeks: two flap mutations (K45R and M46I) and two novel active site mutations (T80I and P81S). Site-directed mutagenesis revealed that all four mutations were required to develop low-level resistance to PL-100, which is indicative of the high genetic barrier of the compound. Importantly, these mutations did not cause cross-resistance to currently marketed PIs. In contrast, the P81S mutation alone caused hypersensitivity to two other PIs, saquinavir (SQV) and nelfinavir (NFV). Analysis of p55Gag processing showed that a marked defect in protease activity caused by mutation P81S could only be compensated when K45R and M46I were present. These data correlated well with the replication capacity (RC) of the mutant viruses as measured by a standard viral growth assay, since only viruses containing all four mutations approached the RC of wild type virus. X-ray crystallography provided insight on the structural basis of the resistance conferred by the identified mutations.

Enhanced Antitumor Efficacy of Clinical-Grade Vasculature-Targeted Liposomal Doxorubicin

Purpose: In vivo evaluation of good manufacturing practice-grade targeted liposomal doxorubicin (TVT-DOX), bound to a CD13 isoform expressed on the vasculature of solid tumors, in human tumor xenografts of neuroblastoma, ovarian cancer, and lung cancer.

Experimental Design: Mice were implanted with lung, ovarian, or neuroblastoma tumor cells via the pulmonary, peritoneal, or orthotopic (adrenal gland) routes, respectively, and treated, at different days post inoculation, with multiple doses of doxorubicin, administered either free or encapsulated in untargeted liposomes (Caelyx) or in TVT-DOX. The effect of TVT-DOX treatment on tumor cell proliferation, viability, apoptosis, and angiogenesis was studied by immunohistochemical analyses of neoplastic tissues and using the chick embryo chorioallantoic membrane assay.

Results: Compared with the three control groups (no doxorubicin, free doxorubicin, or Caelyx), statistically significant improvements in survival was seen in all three animal models following treatment with 5 mg/kg (maximum tolerated dose) of TVT-DOX, with long-term survivors occurring in the neuroblastoma group; increased survival was also seen at a dose of 1.7 mg/kg in mice bearing neuroblastoma or ovarian cancer. Minimal residual disease after surgical removal of neuroblastoma primary mass, and the enhanced response to TVT-DOX, was visualized and quantified by bioluminescence imaging and with magnetic resonance imaging. When treated with TVT-DOX, compared with Caelyx, all three tumor models, as assayed by immunohistochemistry and chorioallantoic membrane, showed statistically significant reductions in cell proliferation, blood vessel density, and microvessel area, showing increased cell apoptosis.

Conclusion: TVT-DOX should be evaluated as a novel angiostatic strategy for adjuvant therapy of solid tumors.

Long-range correlations of density fluctuations in the Kerner-Klenov-Wolf cellular automata three-phase traffic flow model

Detrended fluctuation analysis (DFA) is a useful tool to measure the long-range power-law correlations in 1f noise. In this paper, we investigate the power-law dynamics behavior of the density fluctuation time series generated by the famous Kerner-Klenov-Wolf cellular automata model in road traffic. Then the complexities of spatiotemporal, average speed, and the average density have been analyzed in detail. By introducing the DFA method, our main observation is that the free flow and wide moving jam phases correspond to the long-range anticorrelations. On the contrary, at the synchronized flow phase, the long-range correlated property is observed.

Topical kinetin 0.1% lotion for improving the signs and symptoms of rosacea

Many patients with rosacea are unable to tolerate extended treatment periods with topical agents because of the unusually high skin sensitivity that often accompanies rosacea. Kinetin (N(6)-furfuryladenine) is a plant cytokinin that reportedly helps restore skin barrier function and may be useful to ameliorate the signs and symptoms of rosacea. The purpose of this open-label study was to determine the tolerance and efficacy of twice-daily application of kinetin 0.1% lotion for improving the signs and symptoms of mild to moderate facial rosacea. Subjects applied kinetin 0.1% lotion twice daily to the face, with daily use of a sunscreen of sun protection factor 30. Subjects were evaluated at baseline and at 4-week intervals for 12 weeks to assess efficacy and tolerance. Results of this study suggest that kinetin 0.1% lotion is a well-tolerated moisturizing lotion option for subjects with mild to moderate inflammatory rosacea.

Binding and internalization of NGR-peptide-targeted liposomal doxorubicin (TVT-DOX) in CD13-expressing cells and its antitumor effects

In an effort to develop new agents and molecular targets for the treatment of cancer, aspargine-glycine-arginine (NGR)-targeted liposomal doxorubicin (TVT-DOX) is being studied. The NGR peptide on the surface of liposomal doxorubicin (DOX) targets an aminopeptidase N (CD13) isoform, specific to the tumor neovasculature, making it a promising strategy. To further understand the molecular mechanisms of action, we investigated cell binding, kinetics of internalization as well as cytotoxicity of TVT-DOX in vitro. We demonstrate the specific binding of TVT-DOX to CD13-expressing endothelial [human umbilical vein endothelial cells (HUVEC) and Kaposi sarcoma-derived endothelial cells (SLK)] and tumor (fibrosarcoma, HT-1080) cells in vitro. Following binding, the drug was shown to internalize through the endosomal pathway, eventually leading to the localization of doxorubicin in cell nuclei. TVT-DOX showed selective toxicity toward CD13-expressing HUVEC, sparing the CD13-negative colon-cancer cells, HT-29. Additionally, the nontargeted counterpart of TVT-DOX, Caelyx, was less cytotoxic to the CD13-positive HUVECs demonstrating the advantages of NGR targeting in vitro. The antitumor activity of TVT-DOX was tested in nude mice bearing human prostate-cancer xenografts (PC3). A significant growth inhibition (up to 60%) of PC3 tumors in vivo was observed. Reduction of tumor vasculature following treatment with TVT-DOX was also apparent. We further compared the efficacies of TVT-DOX and free doxorubicin in the DOX-resistant colon-cancer model, HCT-116, and observed the more pronounced antitumor effects of the TVT-DOX formulation over free DOX. The potential utility of TVT-DOX in a variety of vascularized solid tumors is promising.

In vitro antiviral activity and cross-resistance profile of PL-100, a novel protease inhibitor of human immunodeficiency virus type 1

Despite the success of highly active antiretroviral therapy, the current emergence and spread of drug-resistant variants of human immunodeficiency virus (HIV) stress the need for new inhibitors with distinct properties. We designed, produced, and screened a library of compounds based on an original l-lysine scaffold for their potentials as HIV type 1 (HIV-1) protease inhibitors (PI). One candidate compound, PL-100, emerged as a specific and noncytotoxic PI that exhibited potent inhibition of HIV-1 protease and viral replication in vitro (K(i), approximately 36 pM, and 50% effective concentration [EC(50)], approximately 16 nM, respectively). To confirm that PL-100 possessed a favorable resistance profile, we performed a cross-resistance study using a panel of 63 viral strains from PI-experienced patients selected for the presence of primary PI mutations known to confer resistance to multiple PIs now in clinical use. The results showed that PL-100 retained excellent antiviral activity against almost all of these PI-resistant viruses and that its performance in this regard was superior to those of atazanavir, amprenavir, indinavir, lopinavir, nelfinavir, and saquinavir. In almost every case, the increase in the EC(50) for PL-100 observed with viruses containing multiple mutations in protease was far less than that obtained with the other drugs tested. These data underscore the potential for PL-100 to be used in the treatment of drug-resistant HIV disease and argue for its further development.

Chronic celecoxib users more often show regression of gastric intestinal metaplasia after Helicobacter pylori eradication

BACKGROUND AND AIM

To test whether the chronic users of celecoxib, a selective cyclo-oxygenase-2 inhibitor, had less Helicobacter pylori-related intestinal metaplasia or if such users' intestinal metaplasia could be prone to disappear after H. pylori eradication.

METHODS

The study enrolled 150 chronic celecoxib users and 216 non-users who underwent pan-endoscopy to detect H. pylori infection and its related intestinal metaplasia. One hundred and three H. pylori-infected patients with intestinal metaplasia (43 chronic celecoxib users and 60 non-users) received anti-H. pylori therapy and completed the 12-month follow-up to survey the regression of intestinal metaplasia by mean intestinal metaplasia score.

RESULTS

There were no differences in the prevalence of H. pylori-related intestinal metaplasia between the chronic celecoxib users and controls (P > 0.05). On the 12th month of follow-up, chronic celecoxib users had a lower mean intestinal metaplasia score (1.2 vs. 1.8, P < 0.005) and a higher regression rate of intestinal metaplasia (42% vs. 20%, P = 0.027) than non-users.

CONCLUSIONS

With H. pylori infection, chronic celecoxib users still showed limited effects to decrease intestinal metaplasia. Nevertheless, celecoxib should be promising to assist H. pylori eradication for the control of gastric intestinal metaplasia and cancer risk.

PapG II adhesin in the establishment and persistence of Escherichia coli infection in mouse kidneys

Most human pyelonephritogenic Escherichia coli express the PapG II adhesin. However, the role of the PapG II adhesin in enhancing the establishment and persistence of E. coli infection in the kidney is controversial. A pyelonephritogenic strain, EC114, which possesses one copy of the papG II gene, but without other virulence factors (such as S/F1C-fimbriae, hemolysin, and cytotoxic necrotizing factor 1) was selected for the construction of a papG II mutant. The resulting papG II mutant was confirmed by polymerase chain reaction, Southern hybridization, and agglutination assay, and designated as MEC114. We compared MEC114 with the parental strain (EC114) for colonization ability in the bladder and kidney of female BALB/c mice, which were challenged transurethrally with 50 microl of a low (5x10(4) CFU (colony-forming unit)) or high (5x10(8) CFU) dose of EC114 or MEC114 and assessed 1, 3, and 7 days after inoculation. Geometric means of quantitative bacterial counts in the kidney were significantly decreased when challenged with MEC114 on day 3 after inoculation, at both low and high dose (P<0.05), as compared with EC114. On the seventh day, both strains were mainly cleared from the kidney. Renal biopsy showed a similar degree of inflammatory response to both strains 1, 3, and 7 days after inoculation. In brief, the PapG II adhesin can enhance the early establishment of E. coli infection in the kidney, but the bacteria do not maintain infection owing to the host immune response.