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101.
102.
André M Siqueira Lucas I Coutinho Rafael L Gurgel Willian CS Su Luiz M Carvalho Silvana G Benzecry Aline CC Alencar Márcia AA Alexandre Maria Gra?as C Alecrim Marcus VG Lacerda 《Memórias do Instituto Oswaldo Cruz》2014,109(5):540-545
Plasmodium vivax is the most widespread parasite causing malaria, being
especially prevalent in the Americas and Southeast Asia. Children are one of the
most affected populations, especially in highly endemic areas. However, there are
few studies evaluating the therapeutic response of infants with vivax malaria.
This study retrospectively evaluated the parasitaemia clearance in children
diagnosed with vivax malaria during the first five days of exclusive treatment
with chloroquine (CQ). Infants aged less than six months old had a significantly
slower parasitaemia clearance time compared to the group of infants and children
between six months and 12 years old (Kaplan-Meier survival analysis; Wilcoxon
test; p = 0.004). The impaired clearance of parasitaemia in younger children with
vivax malaria is shown for the first time in Latin America. It is speculated that
CQ pharmacokinetics in young children with vivax malaria is distinct, but this
specific population may also allow the detection of CQ-resistant parasites during
follow-up, due to the lack of previous immunity. 相似文献
103.
Krishnamurthy Malathi Takeshi Saito Nannette Crochet David J. Barton Michael Gale Jr Robert H. Silverman 《RNA (New York, N.Y.)》2010,16(11):2108-2119
Triggering and propagating an intracellular innate immune response is essential for control of viral infections. RNase L is a host endoribonuclease and a pivotal component of innate immunity that cleaves viral and cellular RNA within single-stranded loops releasing small structured RNAs with 5′-hydroxyl (5′-OH) and 3′-monophosphoryl (3′-p) groups. In 2007, we reported that RNase L cleaves self RNA to produce small RNAs that function as pathogen-associated molecular patterns (PAMPs). However, the precise sequence and structure of PAMP RNAs produced by RNase L is unknown. Here we used hepatitis C virus RNA as substrate to characterize RNase L mediated cleavage products [named suppressor of virus RNA (svRNA)] for their ability to activate RIG-I like receptors (RLR). The NS5B region of HCV RNA was cleaved by RNase L to release an svRNA that bound to RIG-I, displacing its repressor domain and stimulating its ATPase activity while signaling to the IFN-β gene in intact cells. All three of these RIG-I functions were dependent on the presence in svRNA of the 3′-p. Furthermore, svRNA suppressed HCV replication in vitro through a mechanism involving IFN production and triggered a RIG-I-dependent hepatic innate immune response in mice. RNase L and OAS (required for its activation) were both expressed in hepatocytes from HCV-infected patients, raising the possibility that the OAS/RNase L pathway might suppress HCV replication in vivo. It is proposed that RNase L mediated cleavage of HCV RNA generates svRNA that activates RIG-I, thus propagating innate immune signaling to the IFN-β gene. 相似文献
104.
Rajakumari S Srinivasan M Rajasekharan R 《Journal of biochemical and biophysical methods》2006,68(2):133-137
Detergents serve as means of solubilizing biological membranes and thus play an important role in purification and characterization of membrane proteins. We report here a simple method to estimate the amount of detergent bound to a protein or present in an aqueous solution. The method is based on the turbidity caused by the addition of a detergent to triolein. Detergent bound to an integral membrane protein, lysophosphatidic acid acyltransferase, was separated by native gel electrophoresis and the amount of detergent bound to the same was estimated. This method is applicable for Triton X-100, sodium dodecyl sulfate and zwitterionic detergent, and was validated in the presence of reagents commonly used in membrane protein solubilization and purification. 相似文献
105.
Various urea-derived herbicides and different cytokinin analogues were used to determine their effects on callusing response
and shoot regenerating capacity of alfalfa (Medicago sativa L.) and Coleus (Coleus forskohlii Briq.). The herbicides monuron and diuron evoked profuse callusing response from Coleus leaf segments and alfalfa petiole
explants on Murashige and Skoog medium. Shoot regeneration by monuron (2.0 mg/l) showed a maximum of 3 multiple shoots both
in alfalfa and Coleus with a frequency of 92% and 75%, respectively. Whereas diuron (0.5 mg/l) showed a high frequency of
shoot regeneration (89%) with a mean number of 5 shoots in alfalfa, inC. forskohlii, the frequency of regeneration was 90% with a mean number of 6 shoots. Diuron with two chloride groups in the phenyl ring
showed significantly higher cytokinin-like activity than single chloride substitution monuron. This study demonstrates the
potential use of monuron and diuron as cytokinins in plant tissue culture. 相似文献
106.
Time correlated Single Photon Counting study (TCSPC) was performed for the first time to evaluate the effect of resveratrol
(RES) and genistein (GEN) at 10–100 μM and 10–150 μM respectively, in modulating the DNA conformation and the variation induced
due to intercalation by the dyes, ethidium bromide (EtBr) and acridine orange (AO). It is demonstrated using UV-absorption
and fluorescence spectroscopy that RES and GEN, at 50 μM and 100 μM respectively can bind to DNA resulting in significant
de-intercalation of the dyes, preventing their further intercalation within DNA. Hyperchromicity with red/blue shifts in DNA
when bound to dyes was reduced upon addition of RES and GEN. DNA-dependent fluorescence of EtBr and AO was quenched in the
presence of RES by 87.97% and 79.13% respectively, while similar quenching effect was observed for these when interacted with
GEN (85.52% and 83.85%). It is found from TCSPC analysis that the higher lifetime component or constituent of intercalated
dyes (τ2, A
2) decreased with the subsequent increase in smaller component or constituent of free dye (τ1, A
1) after the interaction of drugs with the intercalated DNA. Thus these findings signify that RES and GEN can play an important
role in modulating DNA intercalation, leading to the reduction in DNA-directed toxicity. 相似文献
107.
Urisman A Molinaro RJ Fischer N Plummer SJ Casey G Klein EA Malathi K Magi-Galluzzi C Tubbs RR Ganem D Silverman RH DeRisi JL 《PLoS pathogens》2006,2(3):e25
Ribonuclease L (RNase L) is an important effector of the innate antiviral response. Mutations or variants that impair function of RNase L, particularly R462Q, have been proposed as susceptibility factors for prostate cancer. Given the role of this gene in viral defense, we sought to explore the possibility that a viral infection might contribute to prostate cancer in individuals harboring the R462Q variant. A viral detection DNA microarray composed of oligonucleotides corresponding to the most conserved sequences of all known viruses identified the presence of gammaretroviral sequences in cDNA samples from seven of 11 R462Q-homozygous (QQ) cases, and in one of eight heterozygous (RQ) and homozygous wild-type (RR) cases. An expanded survey of 86 tumors by specific RT-PCR detected the virus in eight of 20 QQ cases (40%), compared with only one sample (1.5%) among 66 RQ and RR cases. The full-length viral genome was cloned and sequenced independently from three positive QQ cases. The virus, named XMRV, is closely related to xenotropic murine leukemia viruses (MuLVs), but its sequence is clearly distinct from all known members of this group. Comparison of gag and pol sequences from different tumor isolates suggested infection with the same virus in all cases, yet sequence variation was consistent with the infections being independently acquired. Analysis of prostate tissues from XMRV-positive cases by in situ hybridization and immunohistochemistry showed that XMRV nucleic acid and protein can be detected in about 1% of stromal cells, predominantly fibroblasts and hematopoietic elements in regions adjacent to the carcinoma. These data provide to our knowledge the first demonstration that xenotropic MuLV-related viruses can produce an authentic human infection, and strongly implicate RNase L activity in the prevention or clearance of infection in vivo. These findings also raise questions about the possible relationship between exogenous infection and cancer development in genetically susceptible individuals. 相似文献
108.
Sabeena Ahmed Sean Galagan Heather Scobie Jacob Khyang Chai Shwai Prue Wasif Ali Khan Malathi Ram Mohammad Shafiul Alam M. Zahirul Haq Jasmin Akter Gregory Glass Douglas E. Norris Myaing Myaing Nyunt Timothy Shields David J. Sullivan David A. Sack 《PloS one》2013,8(8)
Background
Malaria is endemic in 13 of 64 districts of Bangladesh, representing a population at risk of about 27 million people. The highest rates of malaria in Bangladesh occur in the Chittagong Hill Districts, and Plasmodium falciparum (predominately chloroquine resistant) is the most prevalent species.Methods
The objective of this research was to describe the epidemiology of symptomatic P. falciparum malaria in an area of Bangladesh following the introduction of a national malaria control program. We carried out surveillance for symptomatic malaria due to P. falciparum in two demographically defined unions of the Chittagong Hill Districts in Bangladesh, bordering western Myanmar, between October 2009 and May 2012. The association between sociodemographics and temporal and climate factors with symptomatic P. falciparum infection over two years of surveillance data was assessed. Risk factors for infection were determined using a multivariate regression model.Results
472 cases of symptomatic P. falciparum malaria cases were identified among 23,372 residents during the study period. Greater than 85% of cases occurred during the rainy season from May to October, and cases were highly clustered geographically within these two unions with more than 80% of infections occurring in areas that contain approximately one-third of the total population. Risk factors statistically associated with infection in a multivariate logistic regression model were living in the areas of high incidence, young age, and having an occupation including jhum cultivation and/or daily labor. Use of long lasting insecticide-treated bed nets was high (89.3%), but its use was not associated with decreased incidence of infection.Conclusion
Here we show that P. falciparum malaria continues to be hypoendemic in the Chittagong Hill Districts of Bangladesh, is highly seasonal, and is much more common in certain geographically limited hot spots and among certain occupations. 相似文献109.
A. Ramesh Sundar R. Viswanathan P. Malathi P. Padmanaban 《Archives Of Phytopathology And Plant Protection》2013,46(4):259-272
Abstract A search for plant activators capable of inducing systemic resistance in sugarcane showed that plants pre-treated with synthetic signal inducers confer a high degree of resistance to Colletotrichum falcatum – the red rot pathogen. Among the various treatments, Acibenzolar S- methyl (ASM) was found to be very effective in restricting the pathogen colonization inside the inoculated cane stalk tissues. The induction of resistance was accompanied by a significant increase in peroxidases and polyphenoloxidases activities. A considerable decrease of pathogen titre in the pre-treated tissues as determined by ELISA, clearly demonstrated the restriction of pathogen colonization and proliferation in the sensitized cane stalks. Specific induction of new isoforms of peroxidases and polyphenoloxidases in C. falcatum elicitor treatment indicates the pathogen elicitor induced specific cellular response of sugarcane suspension-cultured cells. 相似文献
110.
S. Malathi S. Madhavan R. Rabindran V. Paranidharan 《Archives Of Phytopathology And Plant Protection》2013,46(20):2524-2532
The effect of elicitor from mycelial walls of Magnaporthe grisea, the rice blast fungus and α-picolinic acid, one of the toxins produced by M. grisea on induction of peroxidase (PO), polyphenol oxidase (PPO) in suspension-cultured rice (Oryza sativa L.) cells was studied. Cultured cells of blast resistant (Usen) and susceptible (CO39) rice genotypes were treated with elicitor (50?μg of glucose equivalents per ml) or α-picolinic acid (400?ppm). The cells were harvested at different time intervals and analysed for the induction of PO and PPO. PO isozyme analysis indicated that the elicitor strongly induced the activities of PO-2 and PO-3 in cultured cells of Usen 3?days after treatment. In Usen, toxin also induced the activities of PO-3 and PO-4. However, similar levels of activities corresponding to these isozymes were recorded 7?days after treatment. In CO39, the activities of PO-1 and PO-2 were induced 3?days after elicitor treatment. In contrast, the toxin suppressed the activity of PO-2. The elicitor induced the activities of PPO-1, PPO-2 and PPO-3 in both Usen and CO39. In Usen, steady increase of PPO-3 was observed and higher level of activity was recorded 5?days after treatment. In CO39, higher level of PPO-3 was observed 1?day after treatment and declined thereafter. However, the activities of PPO-1 and PPO-2 increased 3?days after treatment in CO39. In the toxin-treated cells of Usen, higher level of activity of PPO-3 was observed 3?days after treatment. 相似文献