Quinine resistance (QNR) in Plasmodium falciparum has been detected in many regions of the world where malaria is endemic. Genetic polymorphisms in at least four genes are implicated in QN susceptibility, and their significance often depends on the genetic background of the parasites. In this study, we have culture-adapted 60 P. falciparum clinical isolates from the China-Myanmar border and assessed their in vitro responses to QN. Our results showed that >50% of the parasite isolates displayed reduced sensitivity to QN, with a half-maximal inhibitory concentration (IC 50 ) above 500 nM. Genotyping of pfcrt found that an overwhelming proportion of the parasite population had the chloroquine-resistant genotype, whereas pfmdr1 mutation genotypes and gene amplification were rare. Genotyping of the P. falciparum Na ؉ /H ؉ exchanger gene (pfnhe1) at the minisatellite ms4760 locus identified 10 haplotypes. Haplotype 7, which harbors three copies of the DNNND repeat, was the most predominant, accounting for nearly half of the parasite isolates. Correlation studies did not reveal significant associations of the polymorphisms in pfcrt and pfmdr1 genes with QN response. However, the ms4760 haplotypes were highly associated with in vitro QN responses. In particular, parasite isolates with an increased DNNND copy number tended to have significantly reduced QN susceptibility, whereas parasite isolates with a higher NHNDNHNNDDD copy number had increased QN susceptibility. This study provided further support for the importance of pfnhe1 polymorphisms in influencing QNR in P. falciparum.
Ferulic acid (FA) is a derivative of cinnamic acid. It is used in the treatment of heart head blood-vessel disease and exerts protective effects against hypoxia/ischemia-induced cell injury in the brain. This study investigated the potential neuroprotective effects of FA against ischemia/reperfusion (I/R)-induced brain injury in vivo and in vitro through hematoxylin and eosin (H&E) and Nissl staining assays, flow cytometry, Hoechst 33258 staining, quantitative PCR, western blot analysis and fluorescence microscopic analysis. In this study, models of cerebral I/R injury were established using rats and pheochromocytoma (PC-12) cells. The results revealed that treatment with FA significantly attenuated memory impairment, and reduced hippocampal neuronal apoptosis and oxidative stress in a dose-dependent manner. The results from in vitro experiments also indicated that FA protected the PC-12 cells against I/R-induced reactive oxygen species (ROS) generation and apoptosis by inhibiting apoptosis, Ca2+ influx, superoxide anion (O2−), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) production in a concentration-dependent manner. Moreover, FA inactivated the Toll-like receptor (TLR)/myeloid differentiation factor 88 (MyD88) pathway. MyD88 overexpression abolished the neuroprotective effects of FA. On the whole, we found that FA attenuated memory dysfunction and exerted protective effects against oxidative stress and apoptosis induced by I/R injury by inhibiting the TLR4/MyD88 signaling pathway. This study supports the view that FA may be a promising neuroprotective agent for use in the treatment of cerebral ischemia.
There are socioeconomic and environmental factors and aspects of the child's medical and dietary history that identify children at risk for hospitalization with rotavirus AGE.
Cellular senescence is a hallmark of aging because senescent cells (SCs) accumulate with aging and play a causative role in age-related diseases. Selectively eliminating SCs has been emerging as a new strategy for treating age-related diseases and extending healthspan. Curcumin and its analogs have some anti-aging activities. However, the mechanisms of their action have not been fully elucidated. In the present study, we investigated whether various curcumin analogs can function as a senolytic agent. The results from our studies show that among these curcumin analogs EF24 is the most potent and broad-spectrum senolytic agent. Mechanistically, EF24 selectively kills SCs by inducing SC apoptosis in a reactive oxygen species (ROS) production independent manner but associated with an increase in the proteasome degradation of the Bcl-2 anti-apoptotic protein family proteins known to play an important role in protecting SCs from apoptosis. In addition, EF24 can synergistically kill SCs with ABT-263, a Bcl-2 and Bcl-xl inhibitor and a known senolytic agent. These findings provide new insights into the mechanisms by which curcumin analogs function as an anti-aging agent and suggest that the curcumin analog EF24 has the potential to be used as a novel senolytic agent for the treatment of age-related diseases.
Pertussis hospitalization incidence rates among the youngest infants were generally stable in 1993 to 2004 and were highest for infants 1 to 2 months of age. The impact of the new adolescent and adult tetanus-diphtheria-acellular pertussis vaccines on infant pertussis should be monitored through such discharge databases. Additional vaccination strategies should be evaluated to protect infants as early in life as possible.
The psychological condition of medical students may be influenced by the 2019 novel coronavirus (COVID-19) outbreak. This study investigated the prevalence and influencing factors of depressive symptoms, poor sleep quality and poor diet in students at Kunming Medical University during the early part of the COVID-19 outbreak. A cross-sectional study was used from a questionnaire survey in February 2020. Of a total of 1,026 study participants, the prevalence of depressive symptoms, poor sleep quality, and poor diet was, respectively, 22.4, 33.2, and 17.4%. Male students and students with a low degree of focus on COVID-19 had a high risk of depressive symptoms. A high percentage of females and students in the fifth grade, as well as students with high levels of concern about the negative impact of COVID-19 on their education or employment, comprised those with poor sleep quality. Students in the fifth grade and students with high levels of concern about the negative impact of COVID-19 on their education or employment were more likely to report poor diet. This study suggests the importance of monitoring medical students' depressive state during the COVID-19 outbreak, and universities are encouraged to institute policies and programs to provide educational counseling and psychological support to help students to cope with these problems.
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