82 research outputs found
Anterior Perineal PlanE for ultra-low Anterior Resection of the rectum (APPEAR) technique: A systematic review
Rectal surgery, Perineal incision, Rectal cancer, Inflammatory bowel disease, Rectal strictureRectal surgery, Perineal incision, Rectal cancer, Inflammatory bowel disease, Rectal strictureKathryn Lynes is funded by The David Johnston Fellowship from
The Royal College of Surgeons of England
Public appreciation of lifestyle risk factors for colorectal cancer and awareness of bowel cancer screening: A cross-sectional study
Cardiolipin synthesis in brown and beige fat mitochondria is essential for systemic energy homeostasis
Activation of energy expenditure in thermogenic fat is a promising strategy to improve metabolic health, yet the dynamic processes that evoke this response are poorly understood. Here we show that synthesis of the mitochondrial phospholipid cardiolipin is indispensable for stimulating and sustaining thermogenic fat function. Cardiolipin biosynthesis is robustly induced in brown and beige adipose upon cold exposure. Mimicking this response through overexpression of cardiolipin synthase (Crls1) enhances energy consumption in mouse and human adipocytes. Crls1 deficiency in thermogenic adipocytes diminishes inducible mitochondrial uncoupling and elicits a nuclear transcriptional response through endoplasmic reticulum stress-mediated retrograde communication. Cardiolipin depletion in brown and beige fat abolishes adipose thermogenesis and glucose uptake, which renders animals insulin resistant. We further identify a rare human CRLS1 variant associated with insulin resistance and show that adipose CRLS1 levels positively correlate with insulin sensitivity. Thus, adipose cardiolipin has a powerful impact on organismal energy homeostasis through thermogenic fat bioenergetics
CRISPR-Cas9 screens in human cells and primary neurons identify modifiers of C9ORF72 dipeptide-repeat-protein toxicity.
Hexanucleotide-repeat expansions in the C9ORF72 gene are the most common cause of amyotrophic lateral sclerosis and frontotemporal dementia (c9ALS/FTD). The nucleotide-repeat expansions are translated into dipeptide-repeat (DPR) proteins, which are aggregation prone and may contribute to neurodegeneration. We used the CRISPR-Cas9 system to perform genome-wide gene-knockout screens for suppressors and enhancers of C9ORF72 DPR toxicity in human cells. We validated hits by performing secondary CRISPR-Cas9 screens in primary mouse neurons. We uncovered potent modifiers of DPR toxicity whose gene products function in nucleocytoplasmic transport, the endoplasmic reticulum (ER), proteasome, RNA-processing pathways, and chromatin modification. One modifier, TMX2, modulated the ER-stress signature elicited by C9ORF72 DPRs in neurons and improved survival of human induced motor neurons from patients with C9ORF72 ALS. Together, our results demonstrate the promise of CRISPR-Cas9 screens in defining mechanisms of neurodegenerative diseases
Elevated blood lead levels are associated with reduced risk of malaria in Beninese infants
Introduction
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.
Materials and Methods
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.
Results
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.
Conclusion
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
Cardiolipin Synthesis in Brown and Beige Fat Mitochondria Is Essential for Systemic Energy Homeostasis
Metallothionein (MT) -I and MT-II Expression Are Induced and Cause Zinc Sequestration in the Liver after Brain Injury
Experiments with transgenic over-expressing, and null mutant mice have determined that metallothionein-I and -II (MT-I/II) are protective after brain injury. MT-I/II is primarily a zinc-binding protein and it is not known how it provides neuroprotection to the injured brain or where MT-I/II acts to have its effects. MT-I/II is often expressed in the liver under stressful conditions but to date, measurement of MT-I/II expression after brain injury has focused primarily on the injured brain itself. In the present study we measured MT-I/II expression in the liver of mice after cryolesion brain injury by quantitative reverse-transcriptase PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) with the UC1MT antibody. Displacement curves constructed using MT-I/II knockout (MT-I/II−/−) mouse tissues were used to validate the ELISA. Hepatic MT-I and MT-II mRNA levels were significantly increased within 24 hours of brain injury but hepatic MT-I/II protein levels were not significantly increased until 3 days post injury (DPI) and were maximal at the end of the experimental period, 7 DPI. Hepatic zinc content was measured by atomic absorption spectroscopy and was found to decrease at 1 and 3 DPI but returned to normal by 7DPI. Zinc in the livers of MT-I/II−/− mice did not show a return to normal at 7 DPI which suggests that after brain injury, MT-I/II is responsible for sequestering elevated levels of zinc to the liver. Conclusion: MT-I/II is up-regulated in the liver after brain injury and modulates the amount of zinc that is sequestered to the liver
Participation of metallothionein and superoxide dismutase in the blood of smoking smelters
Objectives: Metallothionein (MT) and two forms of superoxide dismutase (SOD), which are dependent on zinc and copper ions, are involved in defense against the same superoxide anion radicals and are present in extra- and intracellular compartments. The aim of our study was to investigate MT concentration and Cu/Zn SOD activity in the plasma and erythrocyte lysate of the non-smoking and smoking smelters. Material and Methods: The investigations were performed in the blood of 300 male smelters and 100 non-exposed male subjects. We have measured zinc, copper, malondialdehyde (MDA) and MT concentrations as well as SOD activity. Results: We have observed an increase of Cu/Zn coefficient and decrease of Zn/Cu coefficient in the serum of smelters in comparison with the non-smoking control group. Concentration of MDA in the plasma of smelters was higher in comparison with its concentration in the non-smoking control group. The plasma and the erythrocyte lysate MT concentration increased significantly in the whole group of smelters as compared to the non-smoking control group. The mean value of MT concentration in plasma of the smoking smelters was above 2-fold higher than in the non-smoking control group. The activity of Cu/Zn SOD in plasma of the smoking and non-smoking smelters was decreased in comparison with the smoking and non-smoking control groups, respectively. The lowest activity of Cu/Zn SOD, about 2-3‑fold decreased in comparison with the smoking and non-smoking control groups, was detected in plasma of the smelters. An inverse relationship was observed in the erythrocyte lysate. The highest activity of Cu/Zn SOD was reported in the erythrocyte lysate of the smoking smelters and it was about 2-fold higher than in the non-smoking control group. Conclusions: In extracellular environment MT plays a crucial role in comparison with the SOD, while in the intracellular compartment Cu/Zn SOD and MT cooperate with each other
Concentration-Dependent, Size-Independent Toxicity of Citrate Capped AuNPs in Drosophila melanogaster
The expected potential benefits promised by nanotechnology in various fields have led to a rapid increase of the presence of engineered nanomaterials in a high number of commercial goods. This is generating increasing questions about possible risks for human health and environment, due to the lack of an in-depth assessment of the physical/chemical factors responsible for their toxic effects. In this work, we evaluated the toxicity of monodisperse citrate-capped gold nanoparticles (AuNPs) of different sizes (5, 15, 40, and 80 nm) in the model organism Drosophila melanogaster, upon ingestion. To properly evaluate and distinguish the possible dose- and/or size-dependent toxicity of the AuNPs, we performed a thorough assessment of their biological effects, using two different dose-metrics. In the first approach, we kept constant the total surface area of the differently sized AuNPs (Total Exposed Surface area approach, TES), while, in the second approach, we used the same number concentration of the four different sizes of AuNPs (Total Number of Nanoparticles approach, TNN). We observed a significant AuNPs-induced toxicity in vivo, namely a strong reduction of Drosophila lifespan and fertility performance, presence of DNA fragmentation, as well as a significant modification in the expression levels of genes involved in stress responses, DNA damage recognition and apoptosis pathway. Interestingly, we found that, within the investigated experimental conditions, the toxic effects in the exposed organisms were directly related to the concentration of the AuNPs administered, irrespective of their size
Metallothionein ameliorates burn sepsis partly via activation of Akt signaling pathway in mice: a randomized animal study
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