Dramatic Changes of Matrix Metalloproteinases-7 and Lysozyme in the Ulcerative Colitis of Mice Induced by Dextran Sulfate Sodium

Ulcerative colitis （UC） is a lifelong illness with profound emotional and social impacts, and could cause serious damage to large intestine, especially in colon. However, the pathogenesis of UC remained unclear. The present study attempts to find out the role of matrix metalloproteinases-7 （MMP-7） and lysozyme in the pathogenesis of UC through a mice model induced by dextran sulfate sodium （DSS）. The UC model was evaluated both by disease activity index （DAI） and the intestinal histopathology. The results show that there is a high correlation between the DAI score and the pathological changes of colon. Interleukin-6 （IL-6） serum levels and large intestinal fluids levels in UC mice are always higher than that of the control groups, which might be associated with the degree of the inflammation damage in the colon. The change tendency of the MMP-7 mRNA and protein expressions are both up-regulated firstly and then down-regulated from 1 to 5 d in the colon, but only the MMP-7 protein is up-regulated at 7 d again. The up-regulated MMP-7 levels in the early stage of UC may play a protective role through the activated defensins, while the down-regulated levels in the mid-later stage of UC may be connected with the severe lesions in the colon. However, the up-regulated MMP-7 levels in the later stage of UC in the colon may also contribute to the tissue repair or be served as a marker to CRC （colorectal cancer）. The distribution of lysozyme protein indicates that there may be Paneth-like cells in the colon. Both the changes of MMP-7 and lysozyme in the small intestine may play a protective role for the safe environment of the whole gut, especially to the colon of UC.

Study on Soil Respiration Characteristics and Carbon Balance of <i>Kobresia pygmaea</i>Meadow in Qinghai-Tibet Plateau, China

Although soil respiration is the largest contributor to C flux from terrestrial ecosystems to the atmosphere, our understanding of its characteristics and carbon budget in alpine meadow is rather limited because of extremely geographic situation. This study was designed to examine soil CO2 efflux characteristics of diurnal and seasonal variation, thus obtaining estimates of carbon balance of Kobresia pygmaea meadow in Qinghai-Tibet plateau. The results showed that the soil respiration of diurnal and seasonal rate changed little in growing season and was mainly affected by temperature, and single peak curve that showed afternoon appeared. Composite model which was set by soil respiration rate, soil moisture content and temperature (atmospheric temperature and soil temperature) could explain better the variations of soil respiration rate. The variation range of Q10 ranged from 1.28 to 2.34, which was sensitive to temperature in green-up period and late growth stage, and decreased in growth peak period. Meanwhile, during the growing seasons the observed amount of annual carbon fixation via primary production for Kobresia pygmaea meadow ecosystem was about 120.21 g C·m-2·a-1. The carbon dioxide output via soil heterotrophic respiration was about 37.54 g C·m-2·a-1. So carbon budget had more input than output. The Kobresia pygmaea meadow ecosystem has stronger potential to absorb carbon dioxide, it was a sink of atmospheric CO2, and the plant community had a net carbon gain of 82.67 g C·m-2·a-1.

Characterization of bla_(CTX-M) Gene in One Klebsiella pneumoniae Isolate from Sick Chickens in China

Two Klebsiella pneumoniae isolates （Kpcl and Kpc2） were obtained from liver samples of seven dead chickens and identified with Vitek-32 automated identification system. Antimicrobial susceptibilities were determined by the microdilution broth method. Detection of genes encoding class A β-lactamases was performed by PCR amplification, and cloning of the ESBL gene was by plasmid restriction and fragments ligation. Conjugation assay, transformation experiments and plasmid profile analysis were performed. The incompatibility group of ESBL-carrying plasmid was determined by the PCR-based replicon typing method. Lastly, the genetic environment was analysed by direct sequencing of the DNA surrounding the ESBL gene. The genes associated with tetracycline and gentamicin resistance were also sought by PCR. The results revealed that the ESBL phenotype-negative strain Kpc2 only showed resistance to ampicillin, amoxicillin, tetracycline, and doxycycline and carried bla TEM-1 and tet（A） genes. The ESBL-producing strain Kpcl exhibited multidrug resistant phenotype and harbored bla TEM-1 , bla CTX-M-14, tet（A）, tet（B）, and rmtB genes. K. pneumoniae Kpcl contained four plasmids with molecular sizes of approximately 59, 6.9, 2.8, and 1.6 kb, but only a 59-kb plasmid, carried bla TEM-1 and blac CTM-14 genes, was observed in its transconjugant. The incompatibility group of plasmid carrying blaCTX-M-14 gene could not be determined. The bla CTX-M-14 gene was flanked upstream by an ISEcpl insertion sequence and downstream by an IS903 element. This work shows that CTX-M-14 is present in K. pneumoniae isolates from chickens in China. The bla CTX -M-4 gene was associated with an upstream ISEcpl insertion sequence. Our results underline the need for continuous surveillance of the prevalence and evolution of this CTX-M-type β-lactamase in China.

First report on molecular characterization of Leishmania species from cutaneous leishmaniasis patients in southern Khyber Pakhtunkhwa province of Pakistan

Objective: To report presence of Leishmania major in Khyber Pakhtunkhwa of Pakistan, where cutaneous leishmaniasis(CL) is endemic and was thought to be caused by Leishmania tropica only. Methods: Biopsy samples from 432 CL suspected patients were collected from 3 southern districts of Khyber Pakhtunkhwa during years 2011–2016. Microscopy on Giemsa stained slides were done followed by amplification of the ribosomal internal transcribed spacer 1 gene. Results: Leishmania amastigotes were detected by microscopy in 308 of 432 samples(71.3%) while 374 out of 432 samples(86.6%) were positive by ribosomal internal transcribed spacer 1 PCR. Subsequent restriction fragment length polymorphism confirmed Leishmania tropica in 351 and Leishmania major in 6 biopsy samples. Conclusions: This study is the first molecular characterization of Leishmania species in southern Khyber Pakhtunkhwa. It confirmed the previous assumptions that anthroponotic CL is the major CL form present in Khyber Pakhtunkhwa province. Furthermore, this is the first report of Leishmania major from a classical anthroponotic CL endemic focus identified in rural areas of Kohat district in southern Khyber Pakhtunkhwa.

Role of Calcium Ion in Apoptosis of MD Cancer Cells Induced by Arsenic Trioxide

In order to observe the role of calcium ion in apoptosis of MD cancer cells induced by arsenic trioxide, inhibition percentage was detected by MTT assay; morphology changes were examined by fluorescence microscope; apoptosis was examined by DNA Ladder; [Ca^2＋]i was investigated by spectrofluorimeter in vitro on MDCC-MSB 1 cells. The results showed that As2O3 inhibited the proliferation of MDCC-MSB1 cells in concentration dependent manner （P〈0.05 or P〈0.01）; typical apoptosis character was observed by fluorescence microscope; DNA Ladder was observed; the [Ca^2＋]i was elevated significantly after the treatment of As203 （P〈0.05 or P〈0.01） and showed a dose-dependent manner. It is concluded that the calcium may play an important role in apoptosis of MD cancer cells induced by arsenic trioxide.

Research Progress of Using Phage Display Technology to Screen Virus Affinity Peptides

Development and application of phage display technology and research progress of virus affinity peptide were summarized in the paper,and a preliminary outlook for future development was put forward. The paper laid a foundation for development of polypeptide drugs and polypeptide vaccine.

Identification of compatibility between ooplasmic factor and sperm gene in the intersubspecific crosses involving DDK and PWK mice strains

The DDK strain （Mus musculus domesticus） of inbred mouse has a unique peculiarity known as DDK syndrome. The DDK females are mostly infertile when crossed with males of other inbred strains, while DDK males exhibit normal fertility in the reciprocal crosses, as intrastrain matings. This DDK syndrome has been demonstrated to be caused by an incompatibility system between DDK ooplasmic factor and the sperm gene of other strains owing to the ovum mutant （Ore） locus on mouse Chromosome 11. Recently, it was reported that DDK females are fully fertile when crossed to males of MOM （M. m. molossinus） and CASP （M. m. castaneus） strains, indicating that no incompatibilities exist between DDK ooplasmic factor and sperm gene of MOM or CASP males. In the present study, DDK females were found to be also fully fertile when crossed to the males of PWK wild-derived inbred strain （originated from Czech Republic wild mice, M. m. musculus）. The crosses of DDK females × F1 （DDK9 × PWK♀） males also resulted in normal fertility. Furthermore, the transmission ratios of Om alleles from these Fl males to their backcross N2 offspring are 50%：50% as genotyped by microsatellite markers closely linked to Om locus. Moreover, it was demonstrated that PWK females are also fully fertile when crossed to DDK males. All above results indicated that no incompatibility exists between ooplasmic factor and sperm gene in the intersubspecific crosses with DDK and PWK strains. PWK strain would also be useful for further investigations on the DDK syndrome, and DDK strain can be used more widely for various studies in the mouse.