Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0267964 (PAA)
 2,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The nucleotide sequence of the two major Drosophila melanogaster tRNATyr isoacceptors was determined to be pC-C-U-U-C-G-A-U-A-m2G-C-U-C-A-G-D-D-G-G-acp3 U-A-G-A-G-C-m2(2)G-G-psi-G-G-A-C-U-G/Q-psi-A-m1G-A-Um-C-C-A-U-A-G-m7 G-D-C-G-C-U-G-G-U(T)-psi-C-A-m1A-A-U-C-C-G-G-C-U-C-G-A-A-G-G-A-A-C-C-AOH . The two isoacceptors differ by the presence of a G or a Q in the wobble position. Both contain a partial modification in position 54 (U/T). Thus, these tRNAs are transcribed from a single gene (or many genes with identical sequences). A fast and sensitive postlabeling method for sequencing tRNA anticodons is described. Nuclease S-1-treated tRNA is labeled with 5[32P]-pCp using T-4 RNA ligase. The tRNA fragments are then separated on 7 M urea/20% PAA gels. After autoradiography the RNA is eluted and digested with T-2 RNase. The nature of the labeled nucleotides is determined by two-dimensional thin-layer chromatography. The same method can be used to determine the 5' sequence of a tRNA by 3' labeling 5' tRNA halves with 5[32P]-pCp and subsequent chemical sequencing.
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PMID:The nucleotide sequence of two homogeneic Drosophila melanogaster tRNATyr isoacceptors: application of a rapid tRNA anticodon sequencing method using S-1 nuclease. 301 Aug 77

Transient rheological properties and mucoadhesion of hydrogels composed of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO, or Pluronic) block copolymers and poly(acrylic acid) were explored. Nine Pluronic copolymers ranging in nominal molecular weight and PPO/PEO content were grafted to PAA through C-C bonds, with or without the use of divinyl cross-linker, ethylene glycol dimethacrylate (EGDMA). The hydrogel elasticity increased with the PPO content in the copolymers, as well as in the presence of EGDMA. Tensile tests were conducted to measure the fracture strength and the work of adhesion between the hydrogels and rat intestinal tissue. The fracture strength was proportional to the gel pseudoequilibrium modulus and depended on the nominal length of the PPO segments in the parent Pluronic copolymer. The work of mucoadhesion and gel cohesion declined with the loss angle measured in oscillatory shear experiments. The length of the PEO segments in Pluronic affected the work of adhesion. Applications of the Pluronic-PAA gels as vehicles in oral drug delivery are discussed. The longest Pluronic copolymers bonded to PAA resulted in copolymeric gels with strongest mucoadhesive properties.
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PMID:Bioadhesive properties and rheology of polyether-modified poly(acrylic acid) hydrogels. 1533 81

A novel approach toward improvements of oral chemotherapeutic formulations has evolved, which combines solubilisation (molecular dispersion) of the hydrophobic anticancer drugs in micelles attached to large macromolecules or microparticles. The large size of the macromolecules or microgels prevents the gel components from being transported into the systemic circulation. The discussed gels comprise copolymers of poly(acrylic acid) (PAA) and Pluronic surfactants, linked via C-C bonds. The Pluronic-PAA copolymers are non-irritating when administered orally. The micelles formed in the Pluronic-PAA solutions and in crosslinked microgels can be loaded with chemotherapeutic drugs and then released in contact with the intestine. The microgels are collapsed at the acidic pH of the stomach and expand, thus releasing the loaded drugs at the pH of the lower gastrointestinal tract. Yet the microgels are mucoadhesive and enable longer retention time and prolonged release in the colon. Ease of preparation and formulation of the drugs with the Pluronic-PAA polymers and gels may enable the wider use of oral chemotherapy, resulting in a better patient compliance and improved quality of life of the patients.
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PMID:Intelligent hydrogels for the oral delivery of chemotherapeutics. 1629 5

The infrared absorption, Raman spectra and SERS spectra of p-amino acetanilide have been analyzed with the aid of density functional theory calculations at B3LYP/6-311G(d,p) level. The electric dipole moment (mu) and the first hyperpolarizability (beta) values of the investigated molecule have been computed using ab initio quantum mechanical calculations. The calculation results also show that the synthesized molecule might have microscopic nonlinear optical (NLO) behavior with non-zero values. Computed geometries reveal that the PAA molecule is planar, while secondary amide group is twisted with respect to the phenyl ring is found, upon hydrogen bonding. The hyperconjugation of the C=O group with adjacent C-C bond and donor-acceptor interaction associated with the secondary amide have been investigated using computed geometry. The carbonyl stretching band position is found to be influenced by the tendency of phenyl ring to withdraw nitrogen lone pair, intermolecular hydrogen bonding, conjugation and hyperconjugation. The existence of intramolecular C=O...H hydrogen bonded have been investigated by means of the natural bonding orbital (NBO) analysis. The influence of the decrease of N-H and C=O bond orders and increase of C-N bond orders due to donor-acceptor interaction has been identified in the vibrational spectra. The SERS spectral analysis reveals that the large enhancement of in-plane bending, out of plane bending and ring breathing modes in the surface-enhanced Raman scattering spectrum indicates that the molecule is adsorbed on the silver surface in a 'atleast vertical' configuration, with the ring perpendicular to the silver surface.
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PMID:Molecular structure, spectroscopic studies and first-order molecular hyperpolarizabilities of p-amino acetanilide. 1832 71