In this research, Quantum-mechanical calculations were performed at the HF method with the 6-31+G*basis set and at the B3LYP method with the 6-31+G* basis set in the gas phase and five solvents such as water, DMSO, methanol, ethanol and dichloromethane at six temperatures. According to these theoretical results of IR, we extracted thermo chemical parameters such as enthalpy (∆H Kcal/mol), Gibbs...

The stability constants of species present in the systems Ni(II)-pyridoxamine(pym)(A) and Ni(II)-pyridoxamine(pym)(A)-imidazole containing ligands(B) [B = imidazole(him),  benzimidazole(bim), histamine(hist) and L-histidine(his)] have been determined pH-metrically using the MINIQUAD computer program. The existence of the species NiAH, NiA and NiA2 was proven for the Ni(II)-pym(A)...

BACKGROUND Two methoxyl poly(ethylene glycol)-poly(L-histidine)-poly(L-lactide) (mPEG-PH-PLLA) triblock copolymers with different poly(L-histidine) chain lengths were synthesized. The morphology and biocompatibility of these self-assembled nanoparticles was investigated. METHODS Doxorubicin, an antitumor drug, was trapped in the nanoparticles to explore their drug-release behavior. The drug-l...

1. The entire central nervous system (CNS) of the newly born, South American opossum (Monodelphis domestica) was isolated and maintained in basal medium, Eagle's (BME) with 0.2% foetal calf serum and antibiotics. Isolated CNS preparations remained electrically excitable for up to 10 days. The fine structure of the spinal cord was normal after 5 days in culture: axons, synapses, dendrites and gl...

HDC (L-histidine decarboxylase), the enzyme responsible for the catalytic production of histamine from L-histidine, belongs to an evolutionarily conserved family of vitamin B6-dependent enzymes known as the group II decarboxylases. Yet despite the obvious importance of histamine, mammalian HDC enzymes remain poorly characterized at both the biochemical and structural levels. By comparison with ...

Frame, Mary D. S. Conducted signals within arteriolar networks initiated by bioactive amino acids. Am. J. Physiol. 276 (Heart Circ. Physiol. 45): H1012–H1021, 1999.—Our purpose was to determine the specificity of L-arginine (L-Arg)induced conducted signals for intravs. extracellular actions of L-Arg. Diameter and red blood cell velocities were measured for arterioles [18 6 1.6 (SE) μm] in the c...

BACKGROUND 5-Aminolevulinic acid (ALA) and its derivatives have been widely used in photodynamic therapy. The main drawback associated with ALA-based photodynamic therapy (ALA-PDT) and ALA fluorescence diagnosis results from the hydrophilic nature of ALA and lack of selectivity for tumor versus nontumor cells. The application of certain triggers, such as pH, into conventional sensitizers for co...

1. The association and ionization constants for nickel (II) and a selection of L-histidine-containing peptides have been computed together with the constants for copper (II) and acetylglycylglycyl-L-histidylglycine. 2. A close parallel between the titration behavior of copper (II) apomyoglobin complexes and model peptides has been obtained on the assumption that 1 of the 4 bound metal ions is s...