The influence of FWA chemical constitution to the whiteness and UV protection of cotton and cotton/polyester blend

It is well known that the optimal concentration of fluorescent whitening agent (FWA) in the bath results in high whiteness of single component textiles. At the same time, due to fluorescence of FWA, the higher UV protection is achieved as well. However, for the textile blends it is not so easy to achieve. Depending on the fabric chemical composition, different FWAs must be applied. Therefore, the influence of FWA chemical constitution to the whiteness and UV protection of cotton and cotton/polyester blend were researched in this paper. For that purpose, cotton and cotton/polyester blended (50%/50%) fabrics was treated with four different FWAs by Huntsman, Uvitex® brand: BHT, RSB, NFW and EBF. Spectral remission before and after FWA treatment was measured on a remission spectrophotometer Spectraflash SF 300, Datacolor. Whiteness degree was calculated according to ISO 105-J02:1997, and the Tint Deviations and its coloristic meanings were determined according to Griesser. The UV protection of cotton and cotton/polyester fabrics treated with FWA was determined according to AS/NZS 4399:2017 using transmission spectrophotometer Cary 50/Solascreen, Varian. Based on the results obtained,the stilbene disulphonic acid triazine derivative (Uvitex® RSB) can be recommended for use on a cotton/polyester blend.

Effects of Cinnamaldehyde on Smooth Muscle Preparations

The effects of cinnamaldehyde (CNA), known as a transient receptor potential ankyrin 1 (TRPA1) agonist, on guinea-pig ileum and urinary bladder were studied in isolated organ experiments. Contractile effects were found to be present on both preparations. In the ileum, both cholinergic and purinergic (pyridoxalphosphate-6-azophenyl-2′,4′-disulphonic acid tetrasodium salt-sensitive) mechanisms are involved; the TRPA1 antagonist A967079 (1 µmol/L) significantly reduced the response. The contractile response to CNA in the bladder, but not in the ileum, was significantly reduced by in vitro capsaicin desensitization. In the bladder A967079 or the TRPV1 antagonist, BCTC failed to reduce the response. A direct relaxation on the smooth muscle was detected in the precontracted ileum. In the precontracted urinary bladder, CNA also caused relaxation that was insensitive to capsaicin pretreatment. It is suggested that CNA excites the muscles of the bladder via activation of capsaicin-sensitive nerves; in the ileum, it may interact with TRPA1 located on tissue elements that initiate both purinergic and cholinergic mechanisms. The relaxant effects of CNA may be due to the direct inhibition of the smooth muscles.

Simulated diabetic ketoacidosis therapy in vitro elicits brain cell swelling via sodium-hydrogen exchange and anion transport

A common complication of type 1 diabetes mellitus is diabetic ketoacidosis (DKA), a state of severe insulin deficiency. A potentially harmful consequence of DKA therapy in children is cerebral edema (DKA-CE); however, the mechanisms of therapy-induced DKA-CE are unknown. Our aims were to identify the DKA treatment factors and membrane mechanisms that might contribute specifically to brain cell swelling. To this end, DKA was induced in juvenile mice with the administration of the pancreatic toxins streptozocin and alloxan. Brain slices were prepared and exposed to DKA-like conditions in vitro. Cell volume changes were imaged in response to simulated DKA therapy. Our experiments showed that cell swelling was elicited with isolated DKA treatment components, including alkalinization, insulin/alkalinization, and rapid reductions in osmolality. Methyl-isobutyl-amiloride, a nonselective inhibitor of sodium-hydrogen exchangers (NHEs), reduced cell swelling in brain slices elicited with simulated DKA therapy (in vitro) and decreased brain water content in juvenile DKA mice administered insulin and rehydration therapy (in vivo). Specific pharmacological inhibition of the NHE1 isoform with cariporide also inhibited cell swelling, but only in the presence of the anion transport (AT) inhibitor 4,4′-diisothiocyanatostilbene-2,2′-disulphonic acid. DKA did not alter brain NHE1 isoform expression, suggesting that the cell swelling attributed to the NHE1 was activity dependent. In conclusion, our data raise the possibility that brain cell swelling can be elicited by DKA treatment factors and that it is mediated by NHEs and/or coactivation of NHE1 and AT.

Deletion of Slc26a6 alters the stoichiometry of apical Cl−/HCO3− exchange in mouse pancreatic duct

To define the stoichiometry and molecular identity of the Cl−/HCO3− exchanger in the apical membrane of pancreatic duct cells, changes in luminal pH and volume were measured simultaneously in interlobular pancreatic ducts isolated from wild-type and Slc26a6-null mice. Transepithelial fluxes of HCO3− and Cl− were measured in the presence of anion gradients favoring rapid exchange of intracellular HCO3− with luminal Cl− in cAMP-stimulated ducts. The flux ratio of Cl− absorption/HCO3− secretion was ∼0.7 in wild-type ducts and ∼1.4 in Slc26a6−/− ducts where a different Cl−/HCO3− exchanger, most likely SLC26A3, was found to be active. Interactions between Cl−/HCO3− exchange and cystic fibrosis transmembrane conductance regulator (CFTR) in cAMP-stimulated ducts were examined by measuring the recovery of intracellular pH after alkali-loading by acetate prepulse. Hyperpolarization induced by luminal application of CFTRinh-172 enhanced HCO3− efflux across the apical membrane via SLC26A6 in wild-type ducts but significantly reduced HCO3− efflux in Slc26a6−/− ducts. In microperfused wild-type ducts, removal of luminal Cl−, or luminal application of dihydro-4,4′-diisothiocyanatostilbene-2,2′-disulphonic acid to inhibit SLC26A6, caused membrane hyperpolarization, which was abolished in Slc26a6−/− ducts. In conclusion, we have demonstrated that deletion of Slc26a6 alters the apparent stoichiometry of apical Cl−/HCO3− exchange in native pancreatic duct. Our results are consistent with SLC26A6 mediating 1:2 Cl−/HCO3− exchange, and the exchanger upregulated in its absence, most probably SLC26A3, mediating 2:1 exchange.

ATP derived from astrocytes modulates memory in the chick

Memory consolidation in a discriminative bead pecking task is modulated by endogenous adenosine triphosphate (ATP) acting at purinergic receptors in the hippocampus. Consolidation, from short- to intermediate- to long-term memory during two distinct periods following training, was blocked by the non-selective P2 purinergic receptor antagonist PPADS (pyridoxal phosphate-6-azo(benzene-2,4-disulphonic acid) tetrasodium salt hydrate and the specific P2Y1 receptor antagonist MRS2179. Direct injections of the ATP agonists (ATPγS and ADPβS) potentiated memory consolidation and the effect of ADPβS was blocked by MRS2179, suggesting an important role of ATP on memory consolidation via the P2Y1 receptor in the chick hippocampus. Incubation of astrocytes with ATPγS and ADPβS resulted in the increase of intracellular calcium ([Ca2+]i), the latter being blocked by MRS2179 suggesting a specific role for P2Y1 receptors in the calcium response. This response was prevented by blocking astrocytic oxidative metabolism with fluoroacetate. We argue that the source of the ATP acting on neuronal P2Y1 receptors is most likely to be astrocytes. Thrombin selectively increases [Ca2+]i in astrocytes but not in neurones. The main findings of the present study are: (a) astrocytic [Ca2+]i plays an important role in the consolidation of short-term to long-term memory; and (b) ATP released from chick astrocytes during learning modulates neuronal activity through astrocytic P2Y1 receptors.