Helminth parasites of freshwater fishes from Cuatro Ciénegas,Coahuila, in the Chihuahuan Desert of Mexico: inventory and biogeographical implications

As part of an ongoing inventory of the helminth parasites of freshwater fishes in Mexico, 570 individual fish were collected between Apr 2008 and Oct 2011 in 26 localities along the Cuatro Ciénegas region in Coahuila State, northern Mexico. Seventeen species of hosts, mostly corresponding to Nearctic freshwater elements, were studied. A total of 8324 individual worms were collected during this survey, representing 25 species of helminths, of which 9 were digeneans, 3 monogeneans, 3 acanthocephalans, 9 nematodes and 1 cestode. Most of the records in this checklist represent new host or locality records. The information provided in this checklist may be helpful for our understanding of the biodiversity and historical biogeography of this host–parasite system, because in the Cuatro Ciénegas region occur a Nearctic freshwater fish fauna, along with Neotropical and endemic elements, and from a biogeographical point of view, this may represent a transitional area.     

Effects of USP9X down-regulation on apoptosis and invasion ability of gastric carcinoma AGS cells

AIM: To investigate the effects of ubiquitin-specific peptidase 9, X-linked (USP9X) down-regulation on apoptosis and invasion ability in gastric carcinoma cells, and to explore its possible molecular mechanisms. METHODS: USP9X small interfering RNA (siRNA) and control siRNA were used to be transfected into gastric carcinoma AGS cells. The cells were divided into 3 groups, including untreated AGS group, control siRNA group and USP9X siRNA group. The expression of USP9X at mRNA and protein levels in the AGS cells with different treatments was determined by real-time PCR and Western blot. The cell viability was analyzed by CCK-8 assay. Flow cytometry and Boyden chamber were employed to examine the apoptosis and invasion ability of the AGS cells. RESULTS: USP9X siRNA significantly down-regulated the expression of USP9X at mRNA and protein levels in the AGS cells. Down-regulation of USP9X markedly induced apoptosis and reduced invasion ability of the gastric carcinoma AGS cells. Notably, down-regulation of USP9X significantly reduced the protein expression of Mcl-1 and MMP-2, but markedly increased the protein level of Bax. CONCLUSION: USP9X may be a key regulator for apoptosis and invasion in gastric carcinoma.     

Differential responses of cells from human skin keratinocyte and bovine mammary epithelium to attack by pore-forming Staphylococcus aureus alpha-toxin

Human skin keratinocytes HaCat attacked by Staphylococcus aureus α-toxin showed a transient drop of cellular ATP levels whereas in toxin-perforated bovine mammary epithelial cells (BMEC), the ATP levels dropped more slowly. Morphologically, during the ATP level depletion, HaCat cell developed a spacious intracellular vacuole together with the transient influx of trypan blue. WST-1 signal, which tested the function of mitochondrial enzyme in viable cells, also decreased concomitantly. On the other hand, BMEC excluded trypan blue and vacuolation was not observed throughout the experiment. We conclude that mammary epithelial cells resist the toxin better than keratinocytes. This is the first report showing that α-toxin enhances transient membrane permeability to large molecules, temporary vacuole formation and the transient defect of mitochondrial enzyme in viable cells without cell lysis.     

多酚氧化酶基因NtPPOE差异表达的效应分析

为研究烟草中多酚氧化酶基因的功能,本研究从GenBank中挑选一个烟草多酚氧化酶基因Polyphenol oxidase E(基因登录号:NW_015916967.1),命名为NtPPOE.构建NtPPOE基因的CRISPR载体和超表达载体,分别得到NtPPOE基因抑制/过量表达的转化植株.研究表明,基因敲除植株NtP...     

Dynamics of apoptosis-related gene expression during follicular development in yak

The potential reproduction power of domestic animals is limited by a complicated follicular atresia process. P53, caspase-9 (Casp9), Bax, Bcl-2 and Fas play a crucial role in the ovarian mitochondrion-dependent apoptosis and death receptor pathway. In accordance with this study, the expression levels of Casp9, Bax, Bcl-2 and Fas were analysed in ovaries and oviducts of yak by immunohistochemistry (IHC). P53 and the above in ovarian granulosa cells (GCs) from atretic (3–6 mm) to healthy follicles (6–8 mm) and in oviducts were examined from the luteal phase to the follicular phase during the oestrous circle by Western blot (WB) and real-time PCR (RT-PCR). Results demonstrated that typical classic apoptotic factors Casp9, Bax, Bcl-2 and Fas were expressed in the cytoplasm and zonal pellucida of oocytes, primordial follicles, primary follicles, ovarian surface epithelium, ovarian GCs, granular lutein cells, surface epithelia in oviduct uterotubal junction and oviduct ampulla during the luteal phase. RT-PCR and WB revealed that P53 and Fas significantly increased in GCs of atretic follicles. P53 and Casp9 increased in oviduct epithelium during the luteal phase, but Fas was unchanged. A contrary tendency was noted in Bcl-2 and Bax expression. Overall, P53 and Fas play an essential role in inducing GC apoptosis, and Bax, Bcl-2, Casp9 and P53 are involved in oviduct epithelial regeneration in yak.     

Regulation of fibroblast growth factor 9 on the differentiation of goat intramuscular adipocytes

It has been found that fibroblast growth factor receptor (FGF-FGFR) signaling can regulate the expression of adipocyte differentiation genes. FGF9 is one of the members of FGFs that mainly binds receptors FGFR2 and FGFR3. FGF9 is highly expressed in the adipose tissue of humans and mice, but there are few reports on the role of FGF9 in goat intramuscular adipocyte differentiation. Therefore, this study explored the effect of FGF9 on adipocyte differentiation through cell culture, interference, and overexpression. The expression of receptors FGFR1–FGFR4 in adipocyte differentiation and their effects on differentiation were detected to screen receptor gene of FGF9. Finally, the interaction between FGF9 and the receptor was tested by cotransfection. Our results showed that FGF9 interacts with FGFR2 to inhibit goat intramuscular adipocyte differentiation by regulating peroxisome proliferator-activated receptor gamma (PPARγ) and preadipocyte factor 1 (Pref1), which is a data support for subsequent pathway research.     

Population structure of poplar rust Melampsora larici-populina in the UK inferred from AFLP

AFLP profiles were generated from poplar leaf rust ( Melampsora larici-populina ) collected from Populus trichocarpa cv. Trichobel at six sites in the UK in 2001. Of a total of 145 isolates, 121 were unique AFLP phenotypes. On one occasion, the same AFLP phenotype was found at two sites. The analysis indicated that 81·88% of the total variation was attributable to differences among individuals within replicate plots, 3·47% to differences among plots within sites and 14·65% to differences among sites. Weir & Cockerham's θ was calculated as 0·138 and θ ^B , the Bayesian analogue of F _ST, as 0·146. Overall, there was sufficient gene flow among different sites to prevent genetic drift, as Nm was calculated as 1·562 using θ and as 1·462 using θ ^B . Nei's genetic distance and population-assignment test indicated that the rust from a site in north-east England was differentiated from those from other sites. There was no significant correlation between genetic and geographical distances. The results indicate that sexual reproduction has a major influence on the relative lack of population structure of M. larici-populina in the UK.     

ST segment depression and ventricular fibrillation in a dog after contrast agent administration

An 11-year-old Toy Poodle underwent a computed tomography examination with contrast (iohexol) enhancement under anesthesia. Heart rate and R-wave amplitude on electrocardiogram (ECG) increased 2.5 min after iohexol administration, and end-tidal carbon dioxide decreased to 12 mmHg. A progressive ST segment depression was observed on ECG. Subsequently, the ECG waveform changed to ventricular fibrillation. However, spontaneous circulation returned following cardiopulmonary resuscitation. Myocardial ischemia or anaphylactic shock was suspected in the dog, which explains the ST segment depression observed on ECG. When performing radiological examinations with a contrast agent, the ECG waveform changes, such as an increase in heart rate, R-wave amplitude, or ST segment depression, should be carefully monitored. This might enable early detection of cardiac dysfunction and the ensuing cardiac arrest in dogs.     

Effect of idazoxan on permeability of inflammatory blood-brain barrier model in vitro

AIM: To study the effect of idazoxan on the permeability of inflammatory blood-brain barrier (BBB) model in vitro and the expression of tight junction protein ZO-1.METHODS: In vitro BBB model was established by murine brain endothelial cell line bEnd.3 incubated for 7 d. The cells were treated with TNF-α (10 nmol/L) for additional 24 h to establish the inflammatory BBB model, which was pretreated with IDA at doses of 50, 100 and 200 μmol/L, respectively. The permeability was measured using fluorescein isothiocyanate-conjugated dextran (FD-40, MW 40,000), the expression of ZO-1 was detected by Western blot analysis, the distribution of ZO-1 was observed by immunofluorescence, and the mRNA expression of MMP-9/TIMP-1 was measured by RT-PCR.RESULTS: After incubated for 7 d, b.End3 cells converged to be confluent monolayer with low permeability. The inflammatory BBB model induced by TNF-α treatment displayed much higher permeability with decreased expression of tight junction protein ZO-1, destroyed distribution of ZO-1 and increased mRNA expression of MMP-9. When pretreated with IDA, the permeability was greatly decreased, the expression of ZO-1 was greatly increased, the abnormal distribution of ZO-1 was greatly ameliorated and the mRNA expression of MMP-9 was obviously reduced. The effect was most significant in IDA (200 μmol/L)-pretreated group (P<0.01).CONCLUSION: IDA directly acts on brain endothelial cells to reduce the expression of MMP-9, increase the expression of tight junction protein ZO-1 and ameliorate the destroyed distribution of ZO-1 in the inflammatory BBB, thus reversing the abnormally elevated permeability in a inflammatory BBB model in vitro induced by TNF-α.