Predicting Salmonella Typhimurium reductions in poultry ground carcasses

To improve understanding of Salmonella Typhimurium LT2 inactivation in ground poultry carcasses, a series of experiments were carried out at multiple temperatures. Subsequently, a non-linear model was developed to predict Salmonella inactivation at composting and low rendering temperatures. The Salmonella inactivation study was conducted using bench-top experiments at 38, 48, 55, 62.5, 70, and 78°C in mixed and non-mixed reactors using ground poultry carcasses as a feedstock. Subsequently, these observations were used for developing a non-linear model. The model predictions were compared with the observations of a different set of experiments. The comparisons among predictions and observations showed that the model predictions are reasonable and can be useful to determine the time required for Salmonella inactivation in poultry carcasses at multiple temperatures. Results showed that at composting conditions, when temperature varies between 48 and 62.5°C, Salmonella survival can prolong between 10,000 and 25,000 min (7 to 17 d). If ambient temperature is maintained at low temperature rendering range (70 to 78°C), then Salmonella survival can last for 90 to 120 minutes. We anticipate that this study will help in improving the existing understanding of Salmonella survival in poultry carcasses.

Assessing the changes in E. coli levels and nutrient dynamics during vermicomposting of food waste under lab and field scale conditions

Vermicomposting (VC) has proven to be a promising method for treating garden, household, and municipal wastes. Although the VC has been used extensively for converting wastes into fertilizers, pathogens such as Escherichia coli (E. coli) survival during this process is not well documented. In this study, both lab and field scale experiments were conducted assessing the impacts of earthworms in reducing E. coli concentration during VC of food waste. In addition, other pertinent parameters such as temperature, carbon and nitrogen content, moisture content, pH, volatile solids, micronutrients (P, K, Ca, Mg, and S), and heavy metals (Zn, Mn, Fe, and Cu) were monitored during the study. The lab and field scale experiments were conducted for 107 and 103 days, respectively. The carbon to nitrogen ratio (C/N) decreased by 54 % in the lab scale study and by 36 % in the field study. Results showed that VC was not significantly effective in reducing E. coli levels in food waste under both lab and field scale settings. The carbon to nitrogen ratio (C/N) decreased by 54 % in the lab scale study and by 36 % in the field study.

[Effects of microporous polysaccharide on foreign body reaction induced by subcutaneously imbedding expanded polytetrafluoroethylene in mice]

Objective: To observe the effects of early applying of microporous polysaccharide on foreign body reaction induced by subcutaneously imbedding expanded polytetrafluoroethylene (e-PTFE) in mice. Methods: Ten wide type adult C57BL/6J mice were collected and made a full-thickness skin incision on both sides of their back. The two incisions on the back of each mouse were divided into two groups according the random number table, with 10 incisions in each group. A tube-shaped e-PTFE was imbedded into each incision in microporous polysaccharide group, and then 0.03 g microporous polysaccharide was evenly sprayed in the cavity. Whereas, a tube-shaped e-PTFE was imbedded into each incision in control group without other treatment. The incisions in two groups were performed with conventional full-thickness suture. On post operation day (POD) 14, the e-PTFE surrounded with fibrous capsule in each incision of two groups was taken out, and then fibrous capsule tissue was harvested. The thickness of fibrous capsule was observed and measured with HE staining. Collagen fiber distribution in fibrous capsule tissue was observed with Masson staining to calculate the collagen fiber index. Neovascularization and macrophage infiltration in fibrous capsule tissue were observed respectively with immunohistochemical staining, and the numbers of new vessels and macrophages were counted. Data were processed with t test. Results: On POD 14, the thickness of fibrous capsule surrounding e-PTFE imbedded into the incision of microporous polysaccharide group was (127±19) μm, which was significantly thinner than that of control group [(250±35) μm, t=4.13, P<0.05]. On POD 14, the collagen fiber index of fibrous capsule tissue surrounding e-PTFE imbedded into the incision of microporous polysaccharide group was 0.500±0.003, which was significantly higher than that of control group (0.488±0.004, t=5.00, P<0.05). On POD 14, the number of new vessels in fibrous capsule tissue surrounding e-PTFE imbedded into the incision of microporous polysaccharide group was 19±3 per 400 fold visual field, which was significantly more than that of control group (11±3 per 400 fold visual field, t=2.05, P<0.05). On POD 14, the number of macrophages in fibrous capsule tissue surrounding e-PTFE imbedded into the incision of microporous polysaccharide group was 64±5 per 400 fold visual field, which was close to that of control group (66±7 per 400 fold visual field, t=0.78, P>0.05). Conclusions: Topically applying microporous polysaccharide can reduce the formation of fibrous capsule after subcutaneous imbedding of e-PTFE in mice, and it can improve the collagen deposition and angiogenesis but not impact on macrophage infiltration.

[Multiregion sequencing reveals intratumor heterogeneity in esophageal squamous cell carcinoma]

OBJECTIVE

To study the intratumor heterogeneity of esophageal squamous cell carcinoma (ESCC).

METHODS

We used whole-exome sequencing and array-based comparative genomic hybridization to profile mutations and changes in copy number from 11 regions within 2 cases of ESCC and from the metastatic lymph nodes.

RESULTS

The numbers of somatic single nuclear polymorphisms (SNPs) in 4 regions within the tumors in case 1 and case 2 were 93±17 and 124±28, respectively. The majority of SNPs were non synonymous mutations, synonymous mutations, nonsense mutations and splicing junction mutations. The average indels in the 4 tumor regions of case 1 and case 2 were 40±6 and 51±3, respectively. These small indels mainly occurred in exonic (frame-shift and non-frame-shift), untranslational regions of genes and splicing junction regions. All regions from a tumor exhibitedo bvious heterogeneity, and mutational similarity of all four regions within a tumor was less than 25%. Furthermore, gene copy number alteration (gain or loss) varied among multiple regions of a tumor, and the similarity of gene copy number was less than 20%. Phylogenetic analysis of the somatic mutation frequency suggests that multiple, genomic heterogeneous clones co-exist within a primary ESCC, and metastatic subclones may evolve from the primary non-metastatic parental clone. These results indicated that a single-region sampling can not reflect the architecture of the genomic landscape of mutations in ESCC tumors.

CONCLUSIONS

Sequence analysis of whole genome exon in multiple regions can provide strong evidence for genomic heterogeneity in esophageal squamous cell carcinoma.

Association of polymorphisms in intron 2 of FGFR2 and breast cancer risk in Сhinese women

Recent genome-wide association studies (GWAS) demonstrated that genetic variation in intron 2 of fibroblast growth factor receptor 2 (FGFR2) was a novel risk for breast cancer. We investigated whether two SNPs rs1219648 and rs2981582 in intron 2 of FGFR2 were associated with the risk of breast cancer in Chinese women. A total of 340 female breast cancer patients and 400 normal age-matched controls were recruited. Two SNPs were genotyped using matrix-assisted laser desorption/ionization mass spectrometry. The two SNPs rs1219648 and rs2981582 showed no association with the risk of breast cancer. A subgroup analysis by menopausal status demonstrated that the distribution of rs2981582 T alleles, including CT and TT genotypes, was significantly higher in premenopausal patients compared with postmenopausal patients. The TT genotype in rs2981582 was more strongly associated with ER-positive than with ER-negative tumors by ER status analysis. Analysis by haplotypes showed that no haplotypes associated with breast cancer. The results showed no association between two SNPs, rs1219648 and rs2981582 and breast cancer risk, although in a stratified analysis rs2981582 strongly associated with premenopausal and ER-positive breast cancer patients in Chinese women.

Structural and dynamical properties of chlorinated hydrocarbons studied with resonant inelastic x-ray scattering

We present a theoretical and experimental study of resonant inelastic x-ray scattering on a large group of chlorinated hydrocarbons: CH3Cl, CH2Cl2, CHCl3, CCl4, CH3CH2Cl, ClCH2CH2Cl, CH3CHCl2, CH3CCl3, C2H2Cl2-iso, C2H2Cl2-cis, C2H2Cl2-trans, and C6H5Cl. Differences in structural and dynamical properties of the molecules generated by diverse chemical environments are observed in the measured Cl(K(α)) spectral maps as well as in the Cl(K) total fluorescence yield spectra. The energy position, relative intensity, and the width of the Franck-Condon distribution of low-lying σ* and π* resonances are extracted by a fitting procedure taking into account the experimental broadening. The theoretical values obtained with the transition potential and Δ Kohn-Sham methods are in good agreement with the experimental parameters indicating subtle differences due to variations in the molecular structure.

Effects of Sirtuin 1 on the proliferation and osteoblastic differentiation of periodontal ligament stem cells and stem cells from apical papilla

The function of SIRT1 in the proliferation and osteoblastic differentiation of dental stem cells is unclear. The aim of this study was to assess the roles of SIRT1 in these processes using periodontal ligament stem cells (PDLSCs) and stem cells from apical papilla (SCAPs). A defined concentration of resveratrol, an SIRT1 activator, or nicotinamide, an SIRT1 inhibitor, was administered to PDLSCs, SCAPs, and a mixed group of the two cell lines, and their effects on these processes analyzed. Cell proliferation was tested using microtitration with a tetrazolium dye (MTT). Alkaline phosphatase (ALP) activity, mineralization ability, and the expression of osteoblastic differentiation-associated genes were assessed as well. These studies demonstrated that resveratrol could promote cell proliferation of all three groups in a gradually increasing trend over time. In contrast, nicotinamide suppressed the proliferation of the three cell lines. The results also showed that the markers of osteoblastic differentiation: ALP activity, mineralization ability, and the expression levels of the osteoblastic genes ALP, osteopontin, osteocalcin, and bone sialoprotein, were enhanced in the groups with resveratrol treatment. In contrast, following addition of nicotinamide, ALP activity, mineralization ability, and the expression levels of the osteoblastic genes were down-regulated in the cells. Together, these results suggest that the SIRT1 activator and inhibitor compounds, resveratrol and nicotinamide, function at high efficiency in adjusting cell proliferation, and that SIRT1 is a powerful regulator of osteoblastic differentiation of PDLSCs and SCAPs. In addition, co-culture of the two cell lines could promote their abilities of proliferation and osteogenic differentiation.

MiR-1284 modulates multidrug resistance of gastric cancer cells by targeting EIF4A1

Routine chemotherapy as an important treatment mode often can not be effective because of multidrug resistance (MDR). MicroRNA (miRNA) modulates the expression of a great number of genes, including MDR. In this study, the expression of miR-1284 was reduced in gastric cancer (GC) tissue specimens with metastasis and in vincristine-resistant (VCR) GC SGC7901 cells (SGC-7901/VCR) compared to that in the controls. Recombinant lentiviral vectors with miR-1284 led to the overexpression of miR-1284 mRNA and reversed the chemoresistance of SGC7901/VCR cells, promoted cell cycle arrested at the G0/G1 phase, accelerated drug-induced apoptosis, and decreased migration and invasiveness of SGC-7901/VCR. In addition, the overexpression of miR-1284 sensitized tumors to chemotherapy in vivo. Our data provide combined evidence that miR-1284 can heighten the expression of MYC and reduce the expression of JUN, MMP12, and EIF4A1 that was the direct target. In conclusion, miR-1284 can function as a new regulator to reduce GC MDR cells by targeting EIF4A1.

Vacuum ultraviolet excitation luminescence spectroscopy of few-layered MoS2

We report on vacuum ultraviolet (VUV) excited photoluminescence (PL) spectra emitted from a chemical vapor deposited MoS2 few-layered film. The excitation spectrum was recorded by monitoring intensities of PL spectra at ~1.9 eV. A strong wide excitation band peaking at 7 eV was found in the excitation. The PL excitation band is most intensive at liquid helium temperature and completely quenched at 100 K. Through first-principles calculations of photoabsorption in MoS2, the excitation was explicated and attributed to transitions of electrons from p- and d- type states in the valence band to the d- and p-type states in the conduction band. The obtained photon-in/photon-out results clarify the excitation and emission behavior of the low dimensional MoS2 when interacting with the VUV light sources.

Imatinib for highly chemoresistant Kaposi sarcoma in a patient with long-term HIV control: a case report and literature review

Kaposi sarcoma (ks) is a vascular tumour caused by oncogenic human herpesvirus type 8; it often occurs with hiv-associated immunosuppression. Numerous cellular signalling pathways are involved in the pathogenesis of ks, among which receptor tyrosine kinases such as the c-Kit and platelet-derived growth factor receptors play an important role. Imatinib mesylate, a tyrosine kinase inhibitor, has resulted in partial regression of ks lesions in one third of treated patients, but its mechanism of action remains unclear. Here, we report the case of a white man with recurrent ks despite well-suppressed hiv infection and multiple chemotherapies who received imatinib and showed a complete and sustained tumour response. To our knowledge, this report is the first showing the value of imatinib in the management of ks in the context of long-lasting hiv control with adequate quantitative CD4 recovery. Our case indicates that imatinib can be a treatment option for highly chemoresistant recurrent ks in patients on long-term antiretroviral therapy.

Multiple region whole-exome sequencing reveals dramatically evolving intratumor genomic heterogeneity in esophageal squamous cell carcinoma

Cancer is a disease of genome instability and genomic alterations; now, genomic heterogeneity is rapidly emerging as a defining feature of cancer, both within and between tumors. Motivation for our pilot study of tumor heterogeneity in esophageal squamous cell carcinoma (ESCC) is that it is not well studied, but the highest incidences of esophageal cancers are found in China and ESCC is the most common type. We profiled the mutations and changes in copy number that were identified by whole-exome sequencing and array-based comparative genomic hybridization in multiple regions within an ESCC from two patients. The average mutational heterogeneity rate was 90% in all regions of the individual tumors in each patient; most somatic point mutations were nonsynonymous substitutions, small Indels occurred in untranslated regions of genes, and copy number alterations varied among multiple regions of a tumor. Independent Sanger sequencing technology confirmed selected gene mutations with more than 88% concordance. Phylogenetic analysis of the somatic mutation frequency demonstrated that multiple, genomically heterogeneous divergent clones evolve and co-exist within a primary ESCC and metastatic subclones result from the dispersal and adaptation of an initially non-metastatic parental clone. Therefore, a single-region sampling will not reflect the evolving architecture of a genomically heterogeneous landscape of mutations in ESCC tumors and the divergent complexity of this genomic heterogeneity among patients will complicate any promise of a simple genetic or epigenetic diagnostic signature in ESCC. We conclude that any potential for informative biomarker discovery in ESCC and targeted personalized therapies will require a deeper understanding of the functional biology of the ontogeny and phylogeny of the tumor heterogeneity.

Reduction of microbial contamination on the surfaces of layer houses using slightly acidic electrolyzed water

The objective of this study was to evaluate the effectiveness of slightly acidic electrolyzed water (SAEW) in reducing pathogens on pure cultures and on cotton fabric surfaces in the presence of organic matter and estimate its efficacy in comparison with povidone iodine solution for reducing pathogenic microorganisms on internal surfaces of layer houses. Pure cultures of E.coli, S.enteritidis, and S.aureus and cotton fabric surfaces inoculated with these strains were treated with SAEW in the presence of bovine serum albumin (BSA). In the absence of BSA, complete inactivation of all strains in pure cultures and on cotton fabric surfaces was observed after 2.5 and 5 min treatment with SAEW at 40 mg/L of available chlorine concentration (ACC), respectively. The bactericidal efficiency of SAEW increased with increasing ACC, but decreased with increasing BSA concentration. Then, the surfaces of the layer houses were sprayed with SAEW at 60, 80, and 100 mg/L of ACC and povidone iodine using the automated disinfection system at a rate of 110 mL/m(2), respectively. Samples from the floor, wall, feed trough, and egg conveyor belt surfaces were collected with sterile cotton swabs before and after spraying disinfection. Compared to tap water, SAEW and povidone iodine significantly reduced microbial populations on each surface of the layer houses. SAEW with 80 or 100 mg/L of ACC showed significantly higher efficacy than povidone iodine for total aerobic bacteria, staphylococci, coliforms, or yeasts and moulds on the floor and feed trough surfaces (P < 0.05). SAEW was more effective than povidone iodine at reducing total aerobic bacteria, coliforms, and yeasts and moulds on the wall surface. Additionally, SAEW had similar bactericidal activity with povidone iodine on the surface of the egg conveyor belt. Results suggest that SAEW exerts a higher or equivalent bactericidal efficiency for the surfaces compared to povidone iodine, and it may be used as an effective alternative for reducing microbial contamination on surfaces in layer houses.

Modeling disinfection of plastic poultry transport cages inoculated with Salmonella enteritids by slightly acidic electrolyzed water using response surface methodology

In order to reduce the risk of enteric pathogens transmission in animal farms, the disinfection effectiveness of slightly acidic electrolyzed water (SAEW, pH 5.85 to 6.53) for inactivating Salmonella Enteritidis on the surface of plastic poultry transport cages was evaluated. The coupled effects of the tap water cleaning time (5 to 15 s), SAEW treatment time (20 to 40 s), and available chlorine concentrations (ACCs) of 30 to 70 mg/l on the reductions of S. Enteritidis on chick cages were investigated using a central composite design of the response surface methodology (RSM). The established RS model had a goodness of fit quantified by the parameter R2 (0.971), as well as a lack of fit test (P>0.05). The maximum reduction of 3.12 log10 CFU/cm2 for S. Enteritidis was obtained for the cage treated with tap water cleaning for 15 s followed by SAEW treatment for 40 s at an ACC of 50 mg/l. Results indicate that the established RS model has shown the potential of SAEW in disinfection of bacteria on cages.