The function of a well-differentiated nasal epithelium is largely affected by airflow-induced wall shear stress, yet fewmodels recapitulate this dynamic condition. Models which do expose cells to airflow exclusively initiate flow after the differentiation process has occurred., basal cells are constantly replenishing the epithelium under airflow conditions, indicating that airflow may affect the development and function of the differentiated epithelium.
View Article and Find Full Text PDFIn the Asian elephant (), the levels of progesterone products 5α-pregnane, 3α-hydroxypregnane, and 17α-progesterone are elevated during pregnancy. Detection of a sudden decrease in blood progesterone product levels in the final days of pregnancy is considered an objective way of predicting impending parturition. Point-of-care (POC) tests eliminate the cost involved in transporting samples to an external laboratory and provide an almost instant result, facilitating decision-making for animal monitoring and management.
View Article and Find Full Text PDFDeep Vein Thrombosis and pulmonary embolism (DVT/PE) is one of the most common causes of unexpected death for hospital in-patients. D-dimer is used as a biomarker within blood for the diagnosis of DVT/PE. We report a low-cost microfluidic device with a conveniently biofunctionalised interdigitated electrode (IDE) array and a portable impedimetric reader as a point-of-care (POC) device for the detection of D-dimer to aid diagnosis of DVT/PE.
View Article and Find Full Text PDFBiochem Biophys Res Commun
September 2018
Recent environmental sampling around a landfill site in the UK demonstrated that unidentified xenoestrogens were present at higher levels than control sites; that these xenoestrogens were capable of super-activating (resisting ligand-dependent antagonism) the murine variant 2 ERβ and that the ionic liquid 1-octyl-3-methylimidazolium chloride (M8OI) was present in some samples. To determine whether M8OI was a contributor to the xenoestrogen pool in the soils, activation of human estrogen receptors by M8OI was examined. M8OI activated the human ERα in MCF7 cells in a dose-response manner.
View Article and Find Full Text PDFThe pancreas and liver are closely related developmentally and trans-differentiation of cells from one tissue into the cells of the other has been documented to occur after injury or exposure to selected growth factors or glucocorticoid hormones. To generate a readily-expandable source of human hepatocyte-like (H-13) cells, the human pancreatic adenocarcinoma cell (HPAC) line was stably transfected with a construct encoding the variant 2 hepatocyte nuclear factor 4 α (HNF4α) using a piggyBac vector and transient expression of a transposase. Through induction of transgene HNF4α regulated via an upstream glucocorticoid response element in combination with existing modulating effects of glucocorticoid, H-13 cells were converted into quantitatively similar hepatocyte-like (H-13/H) cells based on expression of a variety of hepatocyte proteins.
View Article and Find Full Text PDFBackground & Aims: Primary biliary cholangitis (PBC) is an autoimmune-associated chronic liver disease triggered by environmental factors, such as exposure to xenobiotics, which leads to a loss of tolerance to the lipoic acid-conjugated regions of the mitochondrial pyruvate dehydrogenase complex, typically to the E2 component. We aimed to identify xenobiotics that might be involved in the environmental triggering of PBC.
Methods: Urban landfill and control soil samples from a region with high PBC incidence were screened for xenobiotic activities using analytical, cell-based xenobiotic receptor activation assays and toxicity screens.
The rodent pancreatic AR42J-B13 (B-13) cell line differentiates into non-replicative hepatocyte-like cells in response to glucocorticoid mediated via the glucocorticoid receptor (GR). The aims of this study were to identify a human cell line that responds similarly and investigate the mechanisms underpinning any alteration in differentiation. Exposing the human pancreatic adenocarcinoma (HPAC) cell line to 1-10 µM concentrations of dexamethasone (DEX) resulted an inhibition of proliferation, suppressed carcinoembryonic antigen expression, limited expression of pancreatic acinar and hepatic gene expression and significant induction of the constitutively-expressed hepatic CYP3A5 mRNA transcript.
View Article and Find Full Text PDFTartrazine is a food colour that activates the transcriptional function of the human oestrogen receptor alpha in an in vitro cell model. Since oestrogens are cholestatic, we hypothesised tartrazine will cause periportal injury to the liver in vivo. To test this hypothesis, tartrazine was initially administered systemically to mice resulting in a periportal recruitment of inflammatory cells, increased serum alkaline phosphatase activity and mild periportal fibrosis.
View Article and Find Full Text PDFHigh systemic levels of oestrogens are cholestatic and primary biliary cholangitis (PBC)-which is characterized by hepatic ductular inflammation-is thought to be triggered by exposure to xenobiotics such as those around landfill sites. Xenoestrogens may be a component of this chemical trigger. We therefore hypothesized that xenoestrogens are present at higher levels in the proximity of landfill sites.
View Article and Find Full Text PDFThe decoration of the lipid A headgroups of the lipooligosaccharide (LOS) by the LOS phosphoethanolamine (PEA) transferase (LptA) in Neisseria spp. is central for resistance to polymyxin. The structure of the globular domain of LptA shows that the protein has five disulphide bonds, indicating that it is a potential substrate of the protein oxidation pathway in the bacterial periplasm.
View Article and Find Full Text PDFSuccessful long-term preservation of Mycobacterium tuberculosis cells is important for sample transport, research, biobanking, and the development of new drugs, vaccines, biomarkers, and diagnostics. In this report, Mycobacterium bovis bacillus Calmette-Guérin and M. tuberculosis H37Ra were used as models of M.
View Article and Find Full Text PDFThe generation of affinity reagents, usually monoclonal antibodies, remains a critical bottleneck in biomedical research and diagnostic test development. Recombinant antibody-like proteins such as scFv have yet to replace traditional monoclonal antibodies in antigen detection applications, in large part because of poor performance of scFv in solution. To address this limitation, we have developed assays that use whole yeast cells expressing scFv on their surfaces (yeast-scFv) in place of soluble purified scFv or traditional monoclonal antibodies.
View Article and Find Full Text PDFTissue homeostasis requires an effective, limited wound-healing response to injury. In chronic disease, failure to regenerate parenchymal tissue leads to the replacement of lost cellular mass with a fibrotic matrix. The mechanisms that dictate the balance of cell regeneration and fibrogenesis are not well understood.
View Article and Find Full Text PDFThe indirect flight muscles (IFMs) of Lethocerus (giant water bug) and Drosophila (fruitfly) are asynchronous: oscillatory contractions are produced by periodic stretches in the presence of a Ca(2+) concentration that does not fully activate the muscle. The troponin complex on thin filaments regulates contraction in striated muscle. The complex in IFM has subunits that are specific to this muscle type, and stretch activation may act through troponin.
View Article and Find Full Text PDFAsynchronous insect flight muscles produce oscillatory contractions and can contract at high frequency because they are activated by stretch as well as by Ca2+. Stretch activation depends on the high stiffness of the fibres and the regular structure of the filament lattice. Cytoskeletal proteins may be important in stabilising the lattice.
View Article and Find Full Text PDFApproximately 15% of patients with myasthenia gravis (MG) have thymus neoplasia. These MG with thymoma (MGT) patients show autoantibodies to striated muscle as well as autoantibodies to acetylcholine receptor. To characterize these thymoma-associated muscle antigens, we cloned a number of immunopositive cDNAs by immunoscreening muscle cDNA libraries with sera from MGT patients.
View Article and Find Full Text PDFZ-discs of insect flight muscle contain a large protein of 500-700 kDa. Monoclonal antibodies label an epitope in the molecule at the Z-disc in Drosophila and Lethocerus (waterbug). A partial cDNA of 1.
View Article and Find Full Text PDFTitin is at present the largest known protein (M(r) 3000 kDa) and its expression is restricted to vertebrate striated muscle. Single molecules span from M- to Z-lines and therefore over 1 micron. We have isolated cDNAs encoding five distant titin A-band epitopes, extended their sequences and determined 30 kb (1000 kDa) of the primary structure of titin.
View Article and Find Full Text PDFPartial amino acid sequence was obtained from the massive myofibrillar protein nebulin. This consists of repeating motifs of about 35 residues and super-repeats of 7 x 35 = 245 residues. The repeat-motifs are likely to be largely alpha-helical and to interact with both actin and tropomyosin in thin filaments.
View Article and Find Full Text PDFThick and thin filaments in asynchronous flight muscle overlap nearly completely and thick filaments are attached to the Z-disc by connecting filaments. We have raised antibodies against a fraction of Lethocerus flight muscle myofibrils containing Z-discs and associated filaments and also against a low ionic strength extract of myofibrils. Monoclonal antibodies were obtained to proteins of 800 kd (p800), 700 kd (p700), 400 kd (p400) and alpha-actinin.
View Article and Find Full Text PDFThe faecal microbial flora of two patients with food-related irritable bowel syndrome was examined while they were on a diet excluding symptom-provoking foods, and then on a diet including such a food. The patients reacted differently to the challenge diet but some changes in faecal output, flora and short chain fatty acid content were seen.
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