Pylogenetic relationship of dengue virus type 3 isolated in Brazil and Paraguay and global evolutionary divergence dynamics.
ABSTRACT BACKGROUND: Dengue is the most important mosquito-borne viral disease worldwide. Dengue virus comprises four antigenically related viruses named dengue virus type 1 to 4 (DENV1-4). DENV-3 was re-introduced into the Americas in 1994 causing outbreaks in Nicaragua and Panama. DENV-3 was introduced in Brazil in 2000 and then spread to most of the Brazilian States, reaching the neighboring country, Paraguay in 2002. In this study, we have analyzed the phylogenetic relationship of DENV-3 isolated in Brazil and Paraguay with viruses isolated worldwide. We have also analyzed the evolutionary divergence dynamics of DENV-3 viruses. RESULTS: The entire open reading frame (ORF) of thirteen DENV-3 isolated in Brazil (n= 9) and Paraguay (n= 4) were sequenced for phylogenetic analysis. DENV-3 grouped into three main genotypes (I, II and III). Several internal clades were found within each genotype that we called lineage and sub-lineage. Viruses included in this study belong to genotype III and grouped together with viruses isolated in the Americas within the lineage III. The Brazilian viruses were further segregated into two different sub-lineage, A and B, and the Paraguayan into the sub-lineage B. All three genotypes showed internal grouping. The nucleotide divergence was in average 6.7% for genotypes, 2.7% for lineages and 1.5% for sub-lineages. Phylogenetic trees constructed with any of the protein gene sequences showed the same segregation of the DENV-3 in three genotypes. CONCLUSION: Our results showed that two groups of DENV-3 genotypes III circulated in Brazil during 2002-2009, suggesting different events of introduction of the virus through different regions of the country. In Paraguay, only one group DENV-3 genotype III is circulating that is very closely related to the Brazilian viruses of sub-lineage B. Different degree of grouping can be observed for DENV-3 and each group showed a characteristic evolutionary divergence. Finally, we have observed that any protein gene sequence can be used to identify the virus genotype.
Article: Age-related changes in electrocardiographic responses to trichloroethylene inhalation in conscious rats.[show abstract] [hide abstract]
ABSTRACT: Age-related effects of trichloroethylene (TRI) inhalation on heart rate (HR), its circadian rhythm, the incidence of spontaneous bradyarrhythmias (BA) and ventricular premature contractions (VPC) were examined in conscious rats, as was the dependence of arrhythmias on sleep-wakefulness. Indwelling electrodes were used for simultaneous electrocardiographic (ECG), electroencephalographic (EEG) and electromyographic (EMG) measurements in 2, 13, 20 and 26-month old rats. The rats were exposed for 8 hours to 300 ppm TRI followed by exposure to clean air for 7 days, after which they were exposed to 1,000 ppm for 8 hours. The polygraphic recordings were made during 8-hr exposures and for 28 hours thereafter. Control values for all physiological parameters were measured during 36-hr exposure to clean air. The exposure to TRI exacerbated an age-dependent decrease in HR and its circadian amplitude. Although the spontaneous BA incidence decreased with advancing age, the ratio of the number of BA episodes during the post-exposure period after TRI exposure to those during the corresponding period of clean-air exposure increased more pronouncedly for 20 and 26-month old rats than for 2 and 13-month old rats. The number of spontaneous VPC episodes increased for 20 and 26-month old rats but was not affected by the exposure to TRI. Gas chromatographic analysis of TRI and free trichloroethanol (TRI-OH) in the brain and blood of the TRI-exposed rats revealed the prolonged half-life of TRI and the delayed clearance of free TRI-OH from the tissues with advancing age. The age-related exacerbation of those ECG responses to TRI inhalation appears to be brought about in part by the age-related change in the pharmacokinetics of TRI and TRI-OH.Industrial Health 02/1994; 32(3):129-44. · 0.94 Impact Factor
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ABSTRACT: DAMBE (data analysis in molecular biology and evolution) is an integrated software package for converting, manipulating, statistically and graphically describing, and analyzing molecular sequence data with a user-friendly Windows 95/98/2000/NT interface. DAMBE is free and can be downloaded from http://web.hku.hk/~xxia/software/software.htm. The current version is 4.0.36.Journal of Heredity 92(4):371-3. · 2.80 Impact Factor
Article: Fluid percussion injury transiently increases then decreases brain oxygen consumption in the rat.[show abstract] [hide abstract]
ABSTRACT: The oxygen consumption (VO2 microL/h/mg) of sham and of traumatized rat brains within 30 min and 6 h after a lateral fluid percussion injury (FPI) was measured with the Cartesian microrespirometer. Brain slices were cut at the plain of injury and site-specific 20-60-microg cores of tissue were transferred to the microrespirometer. In sham brains, the cortical VO2 (CVO2) was 13.78+/-0.64 and the hippocampal VO2 (HPVO2) was 11.20+/-0.58 microL/h/mg (p<0.05). Within 30 min of the injury, the respective values of 16.89+/-0.55 and 14.91+/-0.06 were significantly increased (p<0.05). The combined VO2 (CVO2, HPVO2) of 12.49+/-0.06 microL/h/mg in shams was significantly less than the combined VO2 of 15.90+/-0.59 microL/h/mg at 30 min post FPI (p<0.001). The maximal CVO2 of 19.49+/-1.10 microL/h/mg and the maximal HPVO2 of 15.98+/-0.99 microL/h/mg were both obtained from the ipsilateral side of the injury. Whereas the contralateral cortical value for injured brains was not significantly different from that of the shams, both ipsilateral and contralateral hippocampal values were significantly greater than that of the shams in response to injury (p<0.05). By 6 h postinjury, the combined VO2 had dropped to 10.01+/-0.84 microL/h/mg but was not significantly lower than the sham values. The data indicate that normal CVO2 is greater than normal HPVO2. The FPI produces significant increases in both CVO2 and HPVO2. Also, while the immediate increase in CVO2 appears to be injury-site dependent, that is, regional, the increase in HPVO2 appears to be global.Journal of Neurotrauma 01/2000; 17(1):101-12. · 3.65 Impact Factor