The comparative pathology of severe acute respiratory syndrome and avian influenza A subtype H5N1--a review.

The pathology of 2 zoonotic human viral infections that recently emerged, severe acute respiratory syndrome (SARS) due to coronavirus (SARS-CoV) and avian influenza A subtype H5N1, is reviewed and compared based on the literature and the cases examined by the authors. Pneumocytes are the primary target of infection resulting in diffuse alveolar damage. Systemic cytokine activation results in hemophagocytic syndrome, lymphoid depletion, and skeletal muscle fiber necrosis. Severe acute respiratory syndrome induces a more fibrocellular intra-alveolar organization with a "bronchiolitis obliterans organizing pneumonia"-like pattern and presence of multinucleated histiocytes and pneumocytes. H5N1 causes a more fulminant and necrotizing diffuse alveolar damage with patchy and interstitial paucicellular fibrosis. Severe acute respiratory syndrome associated coronavirus persists in the lung up to the second month, whereas H5N1 persists in the lung up to the third week. Severe acute respiratory syndrome associated coronavirus disseminates to blood, urine, feces, gastrointestinal tract, and liver. There is recent report of possible cerebral involvement by H5N1 and its isolation in the blood, gastrointestinal tract, and cerebrospinal fluid. More pathologic studies are urgently needed.

Synthesis of a new chiral source, (1R,2S)-1-Phenylphospholane-2-carboxylic acid, via a key intermediate alpha-phenylphospholanyllithium borane complex: configurational stability and X-ray crystal structure of an alpha-monophosphinoalkyllithium borane complex.

A synthetic route to enantiomerically pure (1R,2S)-1-phenylphospholane-2-carboxylic acid (1), which is a phosphorus analogue of proline, has been established. A key step is the deprotonation-carboxylation of the 1-phenylphospholane borane complex 3 by using sBuLi/1,2-dipiperidinoethane (DPE). Configurational stability of the key intermediate, the amine-coordinated alpha-phosphinoalkyllithium borane complex 4, was investigated by employing lithiodestannylation-carboxylation of both diastereomers of the 1-phenyl-2-trimethylstannylphospholane borane complex 7 in the presence of several kinds of amines, and as a result, 4 was found to be configurationally labile even at -100 degrees C. The key intermediate, the DPE-coordinated trans-1-phenyl-2-phospholanyllithium borane complex 9, was isolated, and the structure was identified by X-ray crystal structure analysis. This is the first X-ray crystal structure determined for an alpha-monophosphinoalkyllithium borane complex. Remarkably, the alkyllithium complex is monomeric and tricoordinate at the lithium center with a slightly pyramidalized environment, and the existence of a Li--C bond (2.170 A) has been confirmed. Moreover, (1)H-(7)Li HOESY and (6)Li NMR analyses suggested the structure of 9 in solution as well as the existence of an equilibrium between 9, its cis isomer, and the ion pair 8 at room temperature, which was extremely biased towards 9 at -100 degrees C. Finally, 1 was used as a chiral ligand in a palladium-catalyzed allylic substitution, and the desired product was obtained in high yield with good enantioselectivity.