instruction:
In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.
question:
Context: Triptolide (TPT), a component of the Chinese herb Triptergium wilfordii, has potent immunosuppressive and anti-inflammatory activity and is used clinically in recipients of kidney transplantation.', 'This work aimed to investigate the effect of TPT on the differentiation of regulatory T lymphocytes (Tregs) from CD4+ cells in rats.', 'MACS-purified rat CD4+ cells were costimulated with anti-CD3 and anti-CD28 in the presence of TGF-beta to induce the expression of FoxP3, which was detected by flow cytometry. TPT and cyclosporine A (CsA) were separately added into the cultures to observe the effect on the expression of FoxP3. Kidney transplantation was performed in rats that either received no treatment or were treated with TPT after transplantation.', 'TPT treatment enhanced the expression of FoxP3 in CD4+ cells, whereas CsA inhibited the FoxP3 expression. In the rat kidney transplantation model, the recipient rats treated with TPT survived longer than the control rats (18-19.83 vs 6.83 days, P<0.05). Meanwhile, the FoxP3+ T cells in the spleens of treated rats were higher than those from the untreated rats (12.4% vs 4.7%, P<0.05).\Question: Does triptolide promote generation of FoxP3+ T regulatory cells in rats?
answer:
These data suggest that TPT may promote the differentiation of CD4+ cells to FoxP3+ Tregs. This would be at least one of the pathways responsible for the immunosuppressive activity of TPT.


question:
Context: Elevated blood lead levels (BLL) and malaria carry an important burden of disease in West Africa. Both diseases might cause anemia and they might entail long-term consequences for the development and the health status of the child. Albeit the significant impact of malaria on lead levels described in Nigeria, no evaluation of the effect of elevated BLL on malaria risk has been investigated so far.', 'Between 2010 and 2012, blood lead levels of 203 Beninese infants from Allada, a semi-rural area 50km North from Cotonou, were assessed at 12 months of age. To assess lead levels, blood samples were analyzed by mass spectrometry. In parallel, clinical, microbiological and hematological data were collected. More precisely, hemoglobin, serum ferritin, CRP, vitamin B12, folate levels, and Plasmodium falciparum parasitemia were assessed and stool samples were also analyzed.', 'At 12 months, the mean BLL of infants was 7.41 μg/dL (CI: 65.2; 83), and 128 infants (63%) had elevated blood lead levels, defined by the CDC as BLL>5 μg/dL. Lead poisoning, defined as BLL>10 μg/dL, was found in 39 infants (19%). Twenty-five infants (12.5%) had a positive blood smear at 12 months and 144 infants were anemic (71%, hemoglobin<110 g/L). Elevated blood lead levels were significantly associated with reduced risk of a positive blood smear (AOR = 0.38, P-value = 0.048) and P. falciparum parasite density (beta-estimate = -1.42, P-value = 0.03) in logistic and negative binomial regression multivariate models, respectively, adjusted on clinical and environmental indicators.\Question: Do elevated Blood Lead Levels Are Associated with Reduced Risk of Malaria in Beninese Infants?
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Our study shows for the first time that BLL are negatively associated with malarial risk considering other risk factors. Malaria is one of the main causes of morbidity and mortality in infants under 5 years worldwide, and lead poisoning is the 6th most important contributor to the global burden of diseases measured in disability adjusted life years (DALYs) according to the Institute of Health Metrics. In conclusion, due to the high prevalence of elevated BLL, health interventions should look forward to minimize the exposure to lead to better protect the population in West Africa.


question:
Context: The activation of Ras signaling and vascular endothelial growth factor (VEGF) expression in mesangial cells is a pathogenic consequence of diabetic nephropathy. We examined the role of simvastatin in modulating Ras signaling and the expression of VEGF in mesangial cells stressed with high doses of glucose in vitro and in vivo.', 'For the in vitro studies, we cultured mesangial cells, with or without simvastatin or manumycin A pretreatment, in 35 mM glucose and assayed VEGF activity. For the in vivo studies, we administered simvastatin or manumycin A to streptozocin-induced diabetic rats for 28 days and dissected renal tissues for an immunohistological assessment of Ras and VEGF expression in glomerular cells.', "We showed that high glucose significantly increased VEGF gene expression and Ras activation. The pretreatment with 10 microM simvastatin and inhibition of Ras activity by manumycin A significantly reversed high glucose promotion of VEGF mRNA expression. Pretreatment with simvastatin and manumycin A clearly affected the activation of Ras promoted by high glucose. Tube-like formations were abundant in high glucose-treated mesangial cells co-cultured with HUVEC. However, the simvastatin and manumycin A treatment group's down-regulated tube formation was comparable to the mesangial cells treated only with high glucose. Exogenous simvastatin and manumycin A treatment alleviated urinary albumin secretion and attenuated Ras activation and VEGF protein expression in the kidneys of diabetic rats.\Question: Does simvastatin alleviate diabetes-induced VEGF-mediated nephropathy via the modulation of Ras signaling pathway?
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Ras protein activation is a key mediator of VEGF-induced diabetic nephropathy. By inhibiting Ras activation, simvastatin modulates the high glucose-induced VEGF-mediated signaling pathway in vitro and in vivo.