miR-19b-3p and miR-20a-5p are associated with the levels of antiphospholipid antibodies in patients with antiphospholipid syndrome.

Monocytes play a key role in pathophysiology of antiphospholipid syndrome (APS), nevertheless it is unclear if microRNA expression is associated with particular APS features. Identify whether miR-19b-3p and miR-20a-5p expression in monocytes are associated with hallmarks of the APS. Fifty-seven APS patients and 18 healthy controls were studied. Expression of miR-19b-3p and miR-20a-5p was measured in monocytes by RT-qPCR. Both miR-19b-3p (AUC = 0.835, 95% CI 0.733-0.938; P < 0.001) and miR-20a-5p (AUC = 0.857, 0.757-0.957; P < 0.001) discriminated APS patients from healthy individuals. A cut-off point of 1.98 for miR-19-3p and 2.18 for miR-20a-5p showed that APS patients with low microRNA expression had higher levels of IgM and IgG anticardiolipin antibodies than patients with high microRNA expression. In addition, APS patients with low microRNA expression had higher IgG anti-ß2 glycoprotein I antibody levels than their counterparts with high microRNA expression. Finally, miR-19b-3p and miR-20a-5p expression levels were significantly higher in APS patients using oral anticoagulants. Monocyte expression of miR-19b-3p and miR-20a-5p is low in APS, and patients with the lowest microRNA expression presented the highest levels of antiphospholipid antibodies.

Micellar anisometry in lyotropic uniaxial nematic phases studied by transversal NMR relaxation dispersion.

A new method, based on the measurement of the (23 )( )Na nuclei spin-spin NMR relaxation times ( T2 ), is proposed to investigate the shape of micelles in lyotropic nematic phases. We investigate the ternary lyotropic mixture of sodium dodecyl sulfate, 1-decanol, and water by using the NMR technique, measuring T2 in the two lyotropic uniaxial nematic phases. The characteristic relaxation time curves of each particular phase are analyzed by considering that they are constituted by a superposition of exponential decays with typical characteristic times: in a sense, a T2 spectroscopy. The analysis of the T2 dispersion profiles in both the uniaxial nematic calamitic and discotic phases indicates that our results can be interpreted in terms of the model of intrinsically biaxial micelles in all the nematic phases.

Reactor scale-up in AOPs: from laboratory to commercial scale.

A procedure to scale-up photoreactors employed in AOPs using laboratory information has been developed. Operating with a model compound the proposed procedure was applied to the decomposition of formic acid in water solution using hydrogen peroxide and UV radiation. With laboratory experiments the parameters of the kinetic equation were obtained in a small batch reactor operated within a recycling apparatus. The whole system was modeled employing radiation and mass balances. These balances were used together with a non-linear parameter estimator to derive the model kinetic constants. Then, these results were used in the modeling of the large-scale reactor to predict exit conversions in an isothermal, continuous, tubular flow reactor that is 2 m long and has a volume of 12 I. Once more, radiation and mass balances were used to predict formic acid output concentrations. Experimental data in the large-scale apparatus are in good agreement with theoretical predictions.

Mixed lipid aggregates containing gangliosides impose different 2H-NMR dynamical parameters on water environment depending on their lipid composition.

Water dynamics in samples of ceramide tetrasaccharide (Gg4Cer) vesicles and GM1 ganglioside micelles at 300:1 water/lipid mole ratio were studied by using deuterium nuclear magnetic resonance (2H-NMR). GM1 imposes a different restriction on water dynamics that is insensitive to temperatures either above or below its phase transition temperature or below the freezing point of water. The calculated correlation times are in the range of 10(-10) s, typical of water molecules near to the polar groups. Pure GM1 micelles have two distinct water microenvironments dynamically characterized. Their dynamic parameters remain constant with temperature ranging from -18 to 32 degrees C, but the amount of strongly associated water is modified. By contrast, a mixture of single soluble carbohydrates corresponding to GM1 polar head group does not preserve the dynamic parameters of water hydration when the temperature is varied. Incorporation of cholesterol or lysophosphatidylcholine into GM1 micelles substantially increases the mobility of water molecules compared with that found in pure GM1 micelles. The overall results indicate that both the supramolecular organization and the local surface quality (lipid-lipid interaction) strongly influence the interfacial water mobility and the extent of hydration layers in glycosphingolipid aggregates.

Water decolorization using UV radiation and hydrogen peroxide: a kinetic study.

Sometimes, provision of water for domiciliary consumption faces the problem of natural contamination originated by the presence of organic substances such as humic or fulvic acids. Very often, after conventional sanitary treatments this water exhibits a persistent yellowish coloration that affects its use. Moreover, these substances may act as precursors of tri-halomethanes formation during pre-disinfection with chlorine. This paper presents, with a simplified mechanistic approach, the intrinsic reaction kinetics of natural water decolorization employing UV radiation and hydrogen peroxide. The main variables for the model are: contaminant concentration expressed as TOC, hydrogen peroxide concentration and the photon absorption rate.

Cytokeratin immunoreactivity in mouse tissues: study of different antibodies with a new detection system.

The cross-reactivity of a group of monoclonal antibodies (MABs) generated against human cytokeratins (CKs) was investigated in mouse tissues. Formalin-fixed and paraffin-embedded sections of lung, stomach, small and large intestine, liver, and kidney were immunostained with MABs after epitope retrieval with enzyme digestion. AE1/AE3, a "cocktail" of two MABs that recognizes basic and acidic CKs, 5D3 MAB to low molecular weight CKs (8, 18, and 19), and monospecific MABs to CK 7 and 20 were tested. Additionally, CK 17 and 34betaE12 MABs to high molecular weight CKs were evaluated in the same organs and in sections from skin and preputial glands. We employed the new universal animal system (ARK) as the detection system. The results showed intense reactivity for the first group of antibodies used, with topographic distribution similar to that in human tissues, with the exception of CK 7 in lung parenchyma, which displayed reactivity only in type II pneumocytes, with negativity of adjacent bronchial epithelium. Also of note was the lack of reaction of liver hepatocytes and renal tubular cells to AE1/AE3 and 5D3 MABs. Regarding the second group of antibodies, no reaction was obtained for CK 17 in the tissues tested. On the contrary, 34betaE12 MAB yielded intense reactivity in cells of epidermis and hair follicles. Compared to other detection systems used previously in this animal, ARK produced a well-defined reactivity at the cellular level without any background. We conclude that a useful panel of anti-CK antibodies commonly used in human pathology can be applied successfully to mouse tissues after enzyme digestion, leading to a more accurate definition of cellular populations in this laboratory animal.

DNA synthesis and nucleolar organizer regions circadian rhythm in mouse regenerating liver hepatocytes.

DNA synthesis and Nucleolar Organizer Regions (NORs) were studied in C3HS inbred mice standardized for periodicity analysis. Immunohistochemical detection of Bromodeoxyuridine (BrdU) incorporated into DNA with a monoclonal antibody and silver staining of NORs (AgNORs) were assessed by means of a digital image analysis system in histological sections of regenerating liver. Tissue samples were obtained at different times after hepatectomy along a circadian span. The results showed a strong correlation of values between DNA synthesis (BrdU labelling index) and AgNOR numbers, with higher counts during the activity period of animals at 00:00/38 and 04:00/42 hours Time of Day/Hours Post-Hepatectomy (TD/HPH), being the differences with other time points highly significant. Our observations demonstrate the existence of a strong correlation of DNA synthesis measured by BrdU incorporation and AgNOR numbers with a defined circadian rhythm in mouse regenerating hepatocytes.

DNA synthesis and nucleolar organizer regions circadian rhythm in mouse regenerating liver hepatocytes.

DNA synthesis and Nucleolar Organizer Regions (NORs) were studied in C3HS inbred mice standardized for periodicity analysis. Immunohistochemical detection of Bromodeoxyuridine (BrdU) incorporated into DNA with a monoclonal antibody and silver staining of NORs (AgNORs) were assessed by means of a digital image analysis system in histological sections of regenerating liver. Tissue samples were obtained at different times after hepatectomy along a circadian span. The results showed a strong correlation of values between DNA synthesis (BrdU labelling index) and AgNOR numbers, with higher counts during the activity period of animals at 00:00/38 and 04:00/42 hours Time of Day/Hours Post-Hepatectomy (TD/HPH), being the differences with other time points highly significant. Our observations demonstrate the existence of a strong correlation of DNA synthesis measured by BrdU incorporation and AgNOR numbers with a defined circadian rhythm in mouse regenerating hepatocytes.

Ganglioside hydration study by 2H-NMR: dependence on temperature and water/lipid ratio.

Dynamic properties of 2H2O in samples of ganglioside aggregates hydrated at water/lipid ratios ranging from 25:1 to 8000:1 mole/mole were studied by using deuterium nuclear magnetic resonance (2H-NMR). We present a physical model for the interpretation of the measured spin-spin relaxation times (T2). For all the concentrations studied the model provides evidence for the existence of at least two kinds of water environments: one in which the rotational correlation time is in the range of 10(-9) to 10(-8) s, and a second in which it lies between 10(-11) to 10(-10) s. A detailed study on the temperature dependence was performed for two of the concentrations, one corresponding to the hexagonal phase (100:1 mole/mole) and the other involving a micellar phase (200:1 mole/mole). In the 100:1 2H2O/ganglioside molar ratio sample, most of the water is tightly bound to long cylindrical structures. For the 200: 1 sample, there are on average approximately 30 water molecules tightly bound to the polar head group of each ganglioside molecule. The relative number and dynamics of molecules in this environment are essentially insensitive to temperature variations in the range 220-300K The rest of water molecules are also influenced by the aggregate, having a different mobility from that observed in the free liquid state.