Intramolecular transesterification of depsides yields fluorescent 1H-isochromen-1-ones: Application as a chemical probe for lichen determination.

The reactivity of eight purified depsides obtained from six european lichens and that display as 2-oxoalkyl chain in ortho-position of the ester bond was explored. These depsides were found to lead to 1H-Isochromen-1-ones, which exhibit a distinctive blue fluorescence at 365 nm, in the presence of a 10% aqueous solution of KOH. A mechanistic explanation, involving the formation of an enolate intermediate and intramolecular transesterification, was proposed and validated by DFT. By exploiting this fluorescent phenomenon, we conceived a chemical probe (the KUV probe) that is useful for lichen determination, as exemplified on a selection of European Porpidia species.

Long-term shelf stability of amphiphilic beta-cyclodextrin nanosphere suspensions monitored by dynamic light scattering and cryo-transmission electron microscopy.

Amphiphilic beta-cyclodextrins (betaCDa) were synthesized by statistically grafting hexanoyl carbon chains on the secondary hydroxyl functions of the betaCD glucopyranosyl units. The obtained derivative was used to prepare submicronic colloidal nanosphere suspensions using a nano-precipitation method. The fresh suspensions contained particles with a diameter ranging from 60-100 nm. Taking into account that the physical stability of colloidal systems remains one of the major problems which can restrict their use in pharmaceutical particulate carrier formulations, the long-term stability of the aqueous nano-dispersions was investigated. Two complementary characterization methods, namely dynamic light scattering and cryo-transmission electron microscopy, were used to control the size distribution and morphology of the nanospheres during storage. The zeta potential was measured as well. An unexpected good physical stability of the suspensions after 3 year storage at room temperature was observed. This behaviour appears to be related to the small size and structural organization of the nanoparticles. The mean diameters determined from light scattering experiments are consistent with those measured from electron micrographs. The slight difference between the values obtained by both methods is discussed.

Obstructive jaundice in children with histiocytosis X.

Prolonged cholestasis was observed in 6 children with histiocytosis X. Operative cholangiograms confirmed the patency of the extrahepatic biliary tree and showed marked distortion of intrahepatic bile ducts resembling that observed in sclerosing cholangitis. Histologic examination showed portal fibrosis in all patients; only one was found to have portal histiocytic infiltration. The subsequent course confirmed the ominous significance of cholestasis in histiocytosis X, a rare finding in this disease: One patient died of progressive liver failure and three others from sepsis after unsuccessful attempts to improve the condition of the liver with chemotherapy.

Histologic study of biliary fibrous remnants in 48 cases of extrahepatic biliary atresia: correlation with postoperative bile flow restoration.

The fibrous remnants of bile ducts that were removed at surgery for extrahepatic biliary atresia were studied by serial section. Forty-eight specimens were classified into three types on the basis of histopathologic changes in the proximal portions of the speciments from the vicinity of the porta hepatis: (1) connective tissue without glands or other epithelial structures (15 cases); (2) connective tissue containing glands lined with cuboidal epithelium (15 cases); (3) connective tissue containing central biliary ducts and peripheral glands (18 cases). Histopathologic changes in sections from distal portions of the specimens did not conform to this classification. A precise correlation of prognostic significance could not be established between these histologic data and postoperative restoration of bile flow, although failure to restore flow was encountered most frequently in cases without demonstrable ducts or glands (TYPE 1).

[Laryngo-pharyngeal paralysis. Complications during the course of myelomeningoceles]. / Les paralysies laryngo-pharyngees. Complications au cours de l'evolution des myelomeningoceles

Report of 5 cases in babies with myèlomeningocele and hydrocephalus stridor and troubles in swallowing appeared after a free interval. These facts were already reported in literature. They represent an impairment of cranial nerves (IX,X and XI). The lesion may be located at the level of the nerves themselves or at the level of the origin nucleus in the brain stem. The mechanism of the lesion is not well known. The role of intracranial hypertension and of Arnold-Chiari malformation seem to be prominent.