One-stage release of congenital constriction band in lower limb from new born to 3 years.

BACKGROUND: Congenital constriction band is the most common cause of terminal congenital malformation of a limb and lymphoedema. Superficial bands do not need any treatment, but deeper bands are managed with excision and Z-plasty. The circumferential bands are released in two to three stages to prevent vascular compromise. The purpose of this study was to present the outcome of one-stage release. MATERIALS AND METHODS: Nineteen children, 12 boys and 7 girls, with 24 congenital constriction bands constituted the clinical material. The mean age at presentation was 57 days (range 12 hours to 3 years) Band was unilateral in 14 and bilateral in five limbs. In unilateral cases, right side was involved in nine cases and left side in five. The constriction band is seen at the junction of middle and distal third. The patients having constriction bands in lower limbs and age less than 3 years were included in the study. One stage circumferential release of congenital constriction band was performed. Our youngest patient was operated at the age of six months. Club feet, (n=8) and lymphedema (n=7) were associated anomalies. Club feet and band were released in one stage in three limbs. The results were evaluated by criteria described by Joseph Upton and Cissy Tan. RESULTS: There were 18 excellent, six satisfactory results. No wound problem occurred. No vascular compromise was noted during or after the procedure. On follow-up, distal swelling reduced. CONCLUSIONS: One-stage circumferential release of congenital constriction band in lower limbs with or without lymphodema is a safe and easy procedure.

Synthesis of "sugar-rods" with phytohemagglutinin cross-linking properties by using the palladium-catalyzed Sonogashira reaction

A palladium-catalyzed Sonogashira reaction has been applied for the syntheses of divalent "sugar-rods" which exhibited excellent lectin cross-linking properties. The procedure, which involves a tetrakis(triphenylphosphine)palladium-catalyzed cross-coupling reaction between an alkyne and a halogen-bearing sp2-carbon in DMF at 60 degrees C, is very efficient and the dimeric or heterobifunctional "sugar-rods" (8-13, 15-17) were isolated in 65-100% yields. Dimers 8a and 15a were both shown to form insoluble cross-linked lattices when mixed with the tetrameric plant lectin from Canavalia ensiformis (Concavalin A, Con A). Moreover, the relative inhibitory properties of the synthetic dimannosides were determined by means of the hemagglutination of rabbit erythrocytes, whereby dimer 15a was shown to be 20-fold more potent than monomeric methyl alpha-D-mannopyranoside.

"Open and Shut" for Guests in Molybdenum-Oxide-Based Giant Spheres, Baskets, and Rings Containing the Pentagon as a Common Structural Element.

A novel exchange between ligands and/or guest molecules can be accomplished in giant molecular spheres (an example is shown in the picture) which are in equilibrium with the corresponding giant baskets in solution.

Intramolecular Excited State Proton Transfer of 2-(2'-Hydroxyphenyl)benzimidazole in Nonionic Micelles: Tweens.

Spectral characteristics and prototropic reactions of 2-(2'-hydroxyphenyl)benzimidazole (HPBI) in Tween-20, Tween-40, Tween-60, Tween-80, and dioxane-water mixtures of different compositions have been studied. Comparison of the fluorescence band maxima of the tautomer band in nonionic micelles with the correlation diagram, drawn between the fluorescence band maxima and the dielectric constants of the dioxane-water mixtures, have shown that the effective dielectric constant (epsiloneff) at the binding site of HPBI is 18 +/- 2 for all the Tweens. Fluorescence lifetimes (tauf) and fluorescence quantum yields (phifl) have shown that the hydrophobicity of these micelles is maximum for Tween-80 and at a minimum for Tween-20. Similar results have also been observed from the pKa values for the deprotonation of HPBI, whereas the protonation reaction of HPBI occurs at the site in nonionic micelles which is more hydrophilic than that where the deprotonation reaction takes place. The protonation reaction in 2-(2'-methoxyphenyl)benzimidazole (MPBI) has shown that the value of epsiloneff in Tweens where this reaction occurs is less hydrophobic than the site where the same reaction occurs in HPBI. Copyright 1998 Academic Press.

Reverse Micelle Formation of Triton X-100 in Butanol and n-Heptane Mixed Solvents Studied by the Positron Annihilation Technique

The positron annihilation technique (PAT) has been applied to study the molecular association phenomenon of Triton X-100 (TX-100) and formation of reversed micelles in the mixed solvent of butanol and n-heptane. The results indicate the sensitivity of positronium (Ps) parameters to the phase transition region due to the self-aggregation phenomenon of TX-100 within the system. The intensity of the long-lived ortho-Ps component, I3, and its lifetime, tau3, show a remarkable change at a critical concentration of the surfactant at approximately 1.5 mM coined as the operational CMC of TX-100 in both (1:1) and (1:2) butanol-n-heptane (BuHp) systems. The narrow component/para-Ps intensity as computed from Doppler broadening of annihilation radiation indicates discernable changes at the same concentration region ( approximately 1.5 mM) of TX-100 in the system. Further, microphase changes due to the association of water molecules within the nonaqueous phase has been studied by Ps parameters, which reveals a clear demarcation of the polar and nonpolar zones.