Studies on the synthesis, characterization, human serum albumin binding and biological activity of single chain surfactant-cobalt(III) complexes.

The interaction of surfactant-cobalt(III) complexes [Co(bpy)(dien)TA](ClO4)3 · 3H2O (1) and [Co(dien)(phen)TA](ClO4)3 · 4H2O (2), where bpy = 2,2'-bipyridine, dien = diethylenetriamine, phen = 1,10-phenanthroline and TA = tetradecylamine with human serum albumin (HSA) under physiological conditions was analyzed using steady state, synchronous, 3D fluorescence, UV/visabsorption and circular dichroism spectroscopic techniques. The results show that these complexes cause the fluorescence quenching of HSA through a static mechanism. The binding constant (Kb ) and number of binding-sites (n) were obtained at different temperatures. The corresponding thermodynamic parameters (∆G°, ∆H° and ∆S°) and Ea were also obtained. According to Förster's non-radiation energy transfer theory, the binding distance (r) between the complexes and HSA were calculated. The results of synchronous and 3D fluorescence spectroscopy indicate that the binding process has changed considerably the polarity around the fluorophores, along with changes in the conformation of the protein. The antimicrobial and anticancer activities of the complexes were tested and the results show that the complexes have good activities against pathogenic microorganisms and cancer cells.

A comparative study on the binding of single and double chain surfactant-cobalt(III) complexes with bovine serum albumin.

The comparative binding effect of single and double aliphatic chain containing surfactant-cobalt(III) complexes cis-[Co(bpy)2(DA)2](ClO4)3·2H2O (1), cis-[Co(bpy)2(DA)Cl](ClO4)2·2H2O (2), cis-[Co(phen)2(CA)2](ClO4)3·2H2O (3), and cis-[Co(phen)2(CA)Cl](ClO4)2·2H2O (4) with bovine serum albumin (BSA) under physiological condition was analyzed by steady state, time resolved fluorescence, synchronous, three-dimensional fluorescence, UV-Visible absorption and circular dichroism spectroscopic techniques. The results show that these complexes cause the fluorescence quenching of BSA through a static mechanism. The binding constants (Kb) and the number of binding sites were calculated and binding constant values are found in the range of 10(4)-10(5) M(-1). The results indicate that compared to single chain complex, double chain surfactant-cobalt(III) complex interacts strongly with BSA. Also the sign of thermodynamic parameters (ΔG°, ΔH°, and ΔS°) indicate that all the complexes interact with BSA through hydrophobic force. The binding distance (r) between complexes and BSA was calculated using Förster non-radiation energy transfer theory and found to be less than 7 nm. The results of synchronous, three dimensional fluorescence and circular dichroism spectroscopic methods indicate that the double chain surfactant-cobalt(III) complexes changed the conformation of the protein considerably than the respective single chain surfactant-cobalt(III) complexes. Antimicrobial studies of the complexes showed good activities against pathogenic microorganisms.

Methadone-exposed newborn infants: outcome after alterations to a service for mothers and infants.

OBJECTIVE: To evaluate the impact of a shared care approach in clinical management with a drug liaison midwife (DLM) service for mothers and infants established in 1995-1996 in an inner city area and to address the problem of congenital abnormality and microcephaly with fetal drug exposure. METHODS: Descriptive analysis of data in live births of women enrolled in a methadone maintenance programme in 1991-1994 (n = 78) and 1997-2001 (n = 98), including time spent in hospital, treatment for neonatal abstinence syndrome (NAS), admission to the neonatal medical unit (NMU) and follow-up for child health checks. RESULTS: In 1997-2001 compared with 1991-1994, the mothers used more methadone in the last week of pregnancy (median 40.0 mg/day vs. 21.5 mg/day, P = 0.0006) and there were more preterm deliveries (36% vs. 21%, P = 0.03). The infants spent less time in hospital (median 5 days vs. 28 days, P < 0.0001), a smaller proportion had treatment for NAS (14% vs. 79%, P < 0.0001), and NMU admission was reduced (median 14 days vs. 26 days, P < 0.0003). Neonatal convulsions (P = 0.0001) and jaundice (P < 0.001) occurred less frequently, and more infants were breastfed (P = 0.001). One infant in each study group had a cleft palate and none had microcephaly. Child health checks for 18-24 months showed a favourable outcome in 1997-2001. CONCLUSIONS: We altered antenatal care and modified neonatal management, subsequently infants spent less time in hospital and NMU admissions were reduced with less NAS treatment. Congenital abnormalities and microcephaly were not common and as regular child health checks were possible, the impact of the DLM service in shared management merits further investigation, for mother-infant bonding and developmental outcome.