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.

[Association of aldosterone synthase gene -344 T/C polymorphism with early renal damage in Han nationality with essential hypertension].

OBJECTIVE: To investigate whether the -344T/C polymorphism of aldosterone synthase gene is associated with early renal damage in Han nationality with essential hypertension in Shandong province. METHODS: Plasma aldosterone concentration and urinary albumin excretion were measured with radioimmunoassays in 225 patients with essential hypertension, and hypertensives were classified as hypertension with normal albuminuria or hypertension with microalbuminuria according to urinary albumin excretion during 24 hours. -344T/C polymorphism of aldosterone synthase gene was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in controls and hypertensives. RESULTS: No significant differences were found in genotype distribution among groups of control, primary hypertension with normal albuminuria and hypertension with microalbuminuria. The C allele frequency in hypertension with microal buminuria group was significantly higher than that in control and hypertension with normal albuminuria group (P < 0.05). In hypertensive patients, plasma aldosterone concentration and urinary albumin excretion of TC+CC genotypes were significantly higher than that of TT genotype ( P< 0.05). CONCLUSION: These results suggest that -344T/C polymorphism of aldosterone synthase gene may be associated with early renal damage in Han nationality with essential hypertension, C allele may be a genetic factor susceptible to renal damage in hypertensives.

Inhibitory effect of rhynchophylline on human ether-a-go-go related gene channel.

We studied the effects of Chinese traditional medicine rhynchophylline (Rhy) on human ether-a-go-go related gene (HERG) channel and characterized the electrophysiological properties of Rhy's pharmacological effect on HERG channel using Xenopus oocytes. Xenopus oocytes were injected with either 23 nl (5.75 ng) HERG cRNA or 23 nl distilled water. Xenopus oocytes were randomly assigned to receive one of the following different concentrations of Rhy: (1) control, (2)10 mumol/L Rhy, (3)100 mumol/L Rhy, (4) 500 mumol/L Rhy, (5) 1 000 mumol/L Rhy, (6) 10 000 mumol/L Rhy. Cell currents were recorded in oocytes. The peak tail currents of HERG channel were inhibited by Rhy. The inhibition was in a dose-dependent manner [IC(50)=(773.4 +/- 42.5) mumol/L]. Experiment with 100 mumol/L Rhy indicated that the degree of HERG blockade showed some voltage dependence (within -40 mV to -20 mV ). Kinetic analyses revealed that Rhy decreased the rate of channel activation. The findings indicate that Rhy inhibits HERG encoded potassium channels. It may underline the molecular mechanism of myocardial electrophysiological characteristics associated with this drug.

[Mutation analysis of a Chinese family with inherited long QT syndrome].

OBJECTIVE: To identify the mutation of a Chinese family with inherited long QT syndrome(LQTS). METHODS: The disease-causing gene was tentatively determined in light of the clinical manifestations and electrophysiological properties, and then polymerase chain reaction and DNA sequencing were used for screening and identifying mutation. RESULTS: A missense mutation G940A(G314S) in the KCNQ1 gene was identified, which was the 'hot spot' of long QT syndrome mutation. CONCLUSION: The mutation that is involved with long QT syndrome in Chinese patients is the same as that in the European, American and Japanese patients.

[Relationship between congenital long QT syndrome and Brugada syndrome gene mutation].

OBJECTIVE: To investigate the molecular pathology in families with long QT syndrome (LQTS) including Jervell-Longe-Nielsen syndrome (JLNS) and Romano-ward syndrome (RWS) and Brugada syndrome (BS) in Chinese population. METHODS: Polymerase chain reaction and DNA sequencing were used to screen for KCNQ1, KCNH2, KCNE1, and SCN5A mutation. RESULTS: We identified a novel mutation N1774S in the SCN5A gene of the BS family, a novel mutation G314S in a RWS family which had also been found in Europe, North America, and Japan, and a single nucleotide polymorphisms (SNPs) G643S in the KCNQ1 of the JLNS family. In this JLNS family, another heterozygous novel mutation in exon 2a was found in KCNQ1 of the patients. CONCLUSION: New mutations were found in our experiment, which expand the spectrum of KCNQ1 and SCN5A mutations that cause LQTS and BS.