ABCB1/P-glycoprotein is an ATP binding cassette transporter that is involved in the clearance of xenobiotics, and it affects the disposition of many drugs in the body. Conformational flexibility of ...the protein within the membrane is an intrinsic part of its mechanism of action, but this has made structural studies challenging. Here, we have studied different conformations of P-glycoprotein simultaneously in the presence of ivacaftor, a known competitive inhibitor. In order to conduct this, we used high contrast cryo-electron microscopy imaging with a Volta phase plate. We associate the presence of ivacaftor with the appearance of an additional density in one of the conformational states detected. The additional density is in the central aqueous cavity and is associated with a wider separation of the two halves of the transporter in the inward-facing state. Conformational changes to the nucleotide-binding domains are also observed and may help to explain the stimulation of ATPase activity that occurs when transported substrate is bound in many ATP binding cassette transporters.
Abstract The Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial randomized men to usual care or annual prostate-specific antigen (PSA) screening for 6 yr and digital rectal ...examination for 4 yr. This trial found no difference between the intervention and usual care arms of the study in the primary end point of prostate cancer (PCa)–specific mortality. The PLCO trial results have had a major impact on health policy and the rate of PSA screening in the United States. We analyzed the 13-yr screening and outcomes data from the 151 participants who died of PCa in the screening arm of the trial to better understand how randomization to screening failed to prevent PCa death in these men. We found that of these men, 81 (53.6%) either were never screened as part of the trial or had an initial positive screen. Only 17 (11.3%) of those who died reached year 6 of the trial with a PSA <4.0 ng/ml. The men who died in the screening arm were also older at study entry than the average PLCO participant (66 vs 62 yr; p < 0.001). Our analysis should inform the interpretation of the PLCO trial and provide insight into future trial design.
Asbestos was widely used as a building material prior to the 1970's. It is well known that asbestos is a health hazard and its progressive elimination is a priority for pollution prevention. Asbestos ...can be transformed to non-hazardous silicate phases by microwave thermal treatment. The aim of this investigation is to describe the microwave inertization process of asbestos containing waste (ACW) and its recycling in porcelain stoneware tiles, porous single-fired wall tiles and ceramic bricks following industrial manufacture procedure. Inertised asbestos powder was added in the percentages of 1, 3, and 5
wt.% to commercially available compositions and then fired following industrial thermal cycles. Water absorption and linear shrinkage of the obtained industrial products do not present significant variations with additions up to 5
wt.% of microwave inertised ACW.
The widespread use of pesticides in the last decades and their accumulation into the environment gave rise to major environmental and human health concerns. To address this topic, the scientific ...community pointed out the need to develop methodologies to detect and measure the presence of pesticides in different matrices. Biosensors have been recently explored as fast, easy, and sensitive methods for direct organophosphate pesticides monitoring. Thus, the present work aimed at designing and testing a 3D printed adapter useful on different equipment, and a membrane support to immobilize the esterase-2 from
Alicyclobacillus acidocaldarius
(EST2) bioreceptor. The latter is labelled with the IAEDANS, a bright fluorescent probe. EST2 was selected since it shows a high specificity toward paraoxon. Our results showed good stability and replicability, with an increasing linear fluorescent intensity recorded from 15 to 150 pmol of labelled EST2. Linearity of data was also observed when using the immobilized labelled EST2 to detect increasing amounts of paraoxon, with a limit of detection (LOD) of 0.09 pmol. This LOD value reveals the high sensitivity of our membrane support when mounted on the 3D adapter, comparable to modern methods using robotic workstations. Notably, the use of an independent support significantly simplified the manipulation of the membrane during experimental procedures and enabled it to match the specificities of different systems. In sum, this work emphasizes the advantages of using 3D printed accessories adapted to respond to the newest research needs.
Graphical abstract
In most myeloma patients, even after several rounds of intensive therapy, drug resistant tumor cells survive and proliferate aggressively leading to relapse. In the present study, gene expression ...profiling of tumor cells isolated from myeloma patients after sequential rounds of chemotherapy, revealed for the first time that heparanase, a potent promoter of myeloma growth and progression, was elevated in myeloma cells that survived therapy. Based on this clinical data, we hypothesized that heparanase was involved in myeloma resistance to drug therapy. In several survival and viability assays, elevated heparanase expression promoted resistance of myeloma tumor cells to chemotherapy. Mechanistically, this enhanced survival was due to heparanase-mediated ERK signaling. Importantly, use of the heparanase inhibitor Roneparstat in combination with chemotherapy clearly diminished the growth of disseminated myeloma tumors in vivo. Moreover, use of Roneparstat either during or after chemotherapy diminished regrowth of myeloma tumors in vivo following therapy. These results provide compelling evidence that heparanase is a promising, novel target for overcoming myeloma resistance to therapy and that targeting heparanase has the potential to prevent relapse in myeloma and possibly other cancers.
We tested whether Δ
14
C values of eye lens protein (crystallin) formed in early life could be utilized to validate marine bony fish age estimates via the bomb radiocarbon chronometer. The slope of ...the relationship between red snapper (Lutjanus campechanus; n = 8; 0 to 27 years old), otolith and eye lens core Δ
14
C values was not significantly different than 1, which was also true for seven additional reef fish species (n = 21; 0 to 24 years old). Results demonstrate eye lens core Δ
14
C can be utilized to validate age estimates of marine fishes, which will be useful in numerous age validation applications.
We tested whether DELTAsup.14C values of eye lens protein (crystallin) formed in early life could be utilized to validate marine bony fish age estimates via the bomb radiocarbon chronometer. The ...slope of the relationship between red snapper (Lutjanus campechanus; n = 8; 0 to 27 years old), otolith and eye lens core DELTAsup.14C values was not significantly different than 1, which was also true for seven additional reef fish species (n = 21; 0 to 24 years old). Results demonstrate eye lens core DELTAsup.14C can be utilized to validate age estimates of marine fishes, which will be useful in numerous age validation applications.
Technological and cultural innovations as well as climate changes are thought to have influenced the diffusion of major language phyla in sub-Saharan Africa. The most widespread and the richest in ...diversity is the Niger-Congo phylum, thought to have originated in West Africa ∼ 10,000 years ago (ya). The expansion of Bantu languages (a family within the Niger-Congo phylum) ∼ 5,000 ya represents a major event in the past demography of the continent. Many previous studies on Y chromosomal variation in Africa associated the Bantu expansion with haplogroup E1b1a (and sometimes its sublineage E1b1a7). However, the distribution of these two lineages extends far beyond the area occupied nowadays by Bantu-speaking people, raising questions on the actual genetic structure behind this expansion. To address these issues, we directly genotyped 31 biallelic markers and 12 microsatellites on the Y chromosome in 1,195 individuals of African ancestry focusing on areas that were previously poorly characterized (Botswana, Burkina Faso, Democratic Republic of Congo, and Zambia). With the inclusion of published data, we analyzed 2,736 individuals from 26 groups representing all linguistic phyla and covering a large portion of sub-Saharan Africa. Within the Niger-Congo phylum, we ascertain for the first time differences in haplogroup composition between Bantu and non-Bantu groups via two markers (U174 and U175) on the background of haplogroup E1b1a (and E1b1a7), which were directly genotyped in our samples and for which genotypes were inferred from published data using linear discriminant analysis on short tandem repeat (STR) haplotypes. No reduction in STR diversity levels was found across the Bantu groups, suggesting the absence of serial founder effects. In addition, the homogeneity of haplogroup composition and pattern of haplotype sharing between Western and Eastern Bantu groups suggests that their expansion throughout sub-Saharan Africa reflects a rapid spread followed by backward and forward migrations. Overall, we found that linguistic affiliations played a notable role in shaping sub-Saharan African Y chromosomal diversity, although the impact of geography is clearly discernible.
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