Vector-Borne Pathogens with Veterinary and Public Health Significance in Melophagus ovinus (Sheep Ked) from the Qinghai-Tibet Plateau.

Melophagus ovinus (sheep ked) is a hematophagous ectoparasite that mainly parasitizes sheep. In addition to causing inflammation, wool loss, and skin damage to the animal hosts, M. ovinus also serves as a vector for a variety of pathogens and is highly likely to participate in the life and transmission cycle of pathogenic organisms. Herein, we investigated the presence and molecular characterization of vector-borne pathogens in M. ovinus from Qinghai-Tibet Plateau, China. A total of 92 M. ovinus pools collected from the Qinghai province of China were screened for the presence of selected vector-borne pathogens. The overall positive rate of A. ovis, A. bovis, A. phagocytophilum, and T. ovis in M. ovinus was 39.1%, 17.4%, 9.8%, and 89.1%, respectively. All of the samples were negative for Border disease virus (BDV), other Anaplasma species, Babesia spp., Rickettsia spp., and Borrelia spp. Co-infection of different Anaplasma species and T. ovis occurred in 51.2% of all samples with T. ovis. The positive rates of A. ovis, A. bovis, and A. phagocytophilum in different regions and altitudes of the sampling sites were significantly different. Sequence and phylogenetic analysis of target genes confirmed their identity with corresponding pathogens. Our results elucidate the occurrence and molecular characterization of Anaplasma spp. and Theileria spp. in M. ovinus, which could act as potential zoonotic reservoirs. To the best of our knowledge, this is the first report of the detection of A. bovis and A. phagocytophilum DNA in M. ovinus. This study gives the first extensive molecular survey of vector-borne pathogens with veterinary and public health significance in M. ovinus from the Qinghai-Tibet Plateau, China.

Spotted Fever Group Rickettsia Infecting Ticks (Acari: Ixodidae), Yak (Bos grunniens), and Tibetan Sheep (Ovis aries) in the Qinghai-Tibetan Plateau Area, China.

The Qinghai-Tibet Plateau Area (QTPA) has a complex natural ecosystem, causing a greatly increased risk of spreading various tick-borne diseases including rickettsial infections, which are regarded as one of the oldest known vector-borne zoonoses. However, the information of one of its pathogen, spotted fever group Rickettsia (SFG Rickettsia), is limited in tick vectors and animals in this area. Therefore, this study focused on the investigation of SFG Rickettsia in tick vectors, yaks (Bos grunniens), and Tibetan sheep (Ovis aries) in the QTPA. A total of 1,000 samples were collected from nine sampling sites, including 425 of yaks, 309 of Tibetan sheep, 266 of ticks. By morphological examination, PCR, and sequencing, we confirmed the species of all collected ticks. All tick samples, all yak and Tibetan sheep blood samples were detected based on SFG Rickettsia ompA and sca4 gene. The results showed that all tick samples were identified to be Haemaphysalis qinghaiensis, and the positive rates of SFG Rickettsia were 5.9% (25/425), 0.3% (1/309), and 54.1% (144/266) in yaks, Tibetan sheep, and ticks, respectively. All positive samples were sequenced, and BLASTn analysis of the ompA gene sequences of SFG Rickettsia showed that all positive samples from animals and ticks had 99.04-100% identity with yak and horse isolates from Qinghai Province, China. BLASTn analysis of the sca4 gene sequences of SFG Rickettsia showed that all positive samples had 97.60-98.72% identity with tick isolates from Ukraine. In addition, the phylogenetic analysis showed that all the SFG Rickettsia ompA and sca4 sequences obtained from this study belong to the same clade as Rickettsia raoultii isolated from livestock and ticks from China and other countries. Molecularly, this study detected and characterized SFG Rickettsia both in the tick vectors and animals, suggesting that the relationship between SFG Rickettsia, tick species and animal hosts should be explored to understand their interrelationships, which provide a theoretical basis for preventing control of this pathogen.

Cycloartane triterpenoids and their glycosides from the rhizomes of Cimicifuga foetida.

A phytochemical study on the rhizomes of Cimicifuga foetida resulted in the isolation of two new cycloartane triterpenoids (1 and 2), eight new cycloartane glycosides (3-10), and six known cycloartane glycoside analogues (11-16). The structures of 1-10 were determined by application of spectroscopic methods, with the absolute configuration of 1 determined by X-ray crystallography. Compounds 1-6, as three pairs of epimers at C-10 and C-24, belong to a seven-membered-ring variant of 9,10-seco-9,19-cycloartane triterpenoids, and glycosides 3-10 were found to be 3-O-ß-D-xylopyranosides. The cytotoxicity of the isolates was evaluated against five selected human tumor cell lines, and the known compounds 15 and 16 showed cytotoxicity against the hepatocellular carcinoma SMMC-7721 cell line with IC50 values of 5.5 and 6.3 µM, respectively.

Cytotoxic constituents from the skin of the toad Bufo bufo gargarizans.

To study the chemical composition of the skin of Bufo bufo gargarizans, various chromatographic methods were used in the isolation procedures and the structures of isolated compounds were determined based on NMR and MS analysis. As a result, two new compounds were isolated from its ethanolic extract and characterized as N-[2-hydroxy-2-(4-hydroxyphenyl)ethyl]-N-methylurea (1) and 19-oxocinobufotalin 3-adipoylarginine ester (2), together with 11 known compounds. Isolated bufadienolides showed significant inhibition effect against human hepatocellular carcinoma cell line SMMC-7721 in vitro.

Studies on cytotoxic constituents from the skin of the toad Bufo bufo gargarizans.

To study the chemical composition of the skin of Bufo bufo gargarizans, many kinds of chromatography methods were used in the isolation procedures, while the structures of isolated compounds were determined on the basis of their NMR and MS spectral analysis. As a result, two new compounds were isolated from its ethanolic extract and characterized as cinobufotalin 3-nonanedioylarginine ester (8) and bufotalin 3-pimeloylarginine ester (14). Furthermore, 13 known compounds were obtained. Isolated bufadienolides showed significant inhibition effect against SMMC-7721 cell lines in vitro.

[The study on three-dimension finite element analysis of the stress distribution in the mandible bone around dental implants].

OBJECTIVE: The aim of this study was to investigate how to model an accuracy 3-dimension Finite Element Analysis (3D-FEA) model. METHODS: Based on computed tomography (CT) scan data of a woman, a 3D finite element model of the first molar on the left was rebuilt by computer imagines process and computer aided design (CAD). Analysis of the stress distribution on a cylinder dental implant and in the bone around it was conducted. RESULTS: The stress distribution showed extremely asymmetry in bucco-lingual section: stress concentrated on the lingual side of the mandible; stress mainly was tensile in buccal side, and on the contrary compressive in lingual side. CONCLUSION: The results were more reliable because this model more really displayed the mandible.

[Effects of simulated body fluid flowing rate on bone-like apatite formation on porous calcium phosphate ceramics].

Objective. Bone-like apatite formation on the surface of calcium phosphate ceramics was believed to be the necessary step that new bone grows on the ceramics and to be relative to the osteoinductivity of the material. This study aimed at investigating the influence of the flow rate of simulated body fluid (SBF) (2 ml/min) in skeletal muscle upon the formation of bone-like apatite on porous calcium phosphate ceramics. Method. The dynamic condition was realized by controlling the SBF flowing in/out of the sample chamber of 100 ml. The flow rate of 2 ml/min is close to that in human muscle environment. The pH and inorganic ionic composition of SBF are close to those of human body fluid. Result. Bone-like apatite formation was relatively easier to occur in static SBF than in dynamic SBF. Experiment with flowing SBF (dynamic SBF) is better in mimicking the living body fluid than static SBF. Conclusion. The results from dynamic SBF may more truly show the relation between apatite layer formation and osteoinduction in biomaterials than that from in vitro experiments before.