One simple structural change in compound (I), the destruction of its symmetry by its conversion into n-propyl-2-pyridyl disulphide [III, R = C3H7(propyl)-S-S-2-Py], has permitted the demonstration of an important property of the thiol proteinases, the existence of nucleophilic character in the uninterrupted thiol-imidazole interactive systems of their active centres. The reactions of 2-Py-S-S-2...

Short-lived nucleoprotein complexes (r-py complex) containing replicating polyoma DNA were isolated from infected cells after lysis with Triton X-100. The Triton lysing procedure of Green, Miller, and Hendler (1971) releases most complexes containing supercoiled viral DNA (py complex) from nuclei, but liberates only a portion of r-py complexes. r-py Complexes are associated more strongly with n...

Hairy vetch (Vicia villosa Roth) is the second most cultivated worldwide being used as a forage and cover crop. As it not domesticated, displays several wild traits including seed dormancy. The physical dormancy (PY) variation could be useful depending on specific context. High PY desirable for ley farming systems, while low needed to prevent weediness in subsequent crop rotations. Gene flow be...

The reactions of methyl(2-pyridyl)ketone oxime, (py)C(Me)NOH, with manganese(II) sulfate monohydrate have been investigated. The reaction between equimolar quantities of MnSO(4) . H(2)O and (py)C(Me)NOH in H(2)O lead to the dinuclear complex [Mn(2)(SO(4))(2){(py)C(Me)NOH}(4)] . (py)C(Me)NOH, 1 . (py)C(Me)NOH, while employment of NaOMe as base affords the compound [Mn(HCO(2))(2){(py)C(Me)NOH}(2)...

Src homology 2 (SH2) domains recognize phosphotyrosine (pY)-containing sequences and thereby mediate their association to ligands. Bruton's tyrosine kinase (Btk) is a cytoplasmic protein tyrosine kinase, in which mutations cause a hereditary immunodeficiency disease, X-linked agammaglobulinemia (XLA). Mutations have been found in all Btk domains, including SH2. We have analyzed the structural a...

Little is known about the impact of drug resistance on recurrence in TB. We conducted a cohort study to measure the impact of multi-drug resistance (MDR) on TB recurrence over nine years in Henan Province China. We reviewed medical records and conducted field interviews of 100 MDR and 150 non-MDR TB patients who were treated between 2001 and 2002. We compared long-term recurrence rates, risk fa...

Chiral recognition of protein-binding sites by a simple organic molecule with selectivities >100 is reported here. The l-isomer of 4(1-pyrene)-3-butyroyl-phenylalanine amide (Py-L-Phe) binds to BSA with an affinity constant (K(b)) of 3 x 10(7) M(-1), whereas the corresponding D-isomer (Py-D-Phe) binds 100 times weaker. The enantiomers showed contrasting spectral changes when bound to BSA. Where...

The toxicities of phenanthrene (PH) and pyrene (PY) are less than benzo (a) pyrene (BaP) , but both compounds are found in higher concentrations in the air, feed, and food. Most PAHs are metabolized to hydroxylated compounds by the hepatic cytochrome P450 monooxigenases system. Metabolites are excreted into urine and feces. We determined concentrations of PH, PY and BaP in muscle and hydroxylat...