Babies with brain damage who can not swallow: surgical management

BACKGROUND: Neonates with severe neurological impairment are often unable to swallow, necessitating gastrostomy for feeding. Because of the risk of developing severe reflux, this procedure is often associated with fundoplication. OBJECTIVE: To assess the safety and efficacy of gastrostomy and Nissen fundoplication in 22 neonates with swallowing difficulties due to serious neurological impairment. METHOD: All children underwent an initial period of nasogastric feeding and after informed consent underwent gastrostomy and Nissen fundoplication. RESULTS: There were no significant intraoperative complications. There were two cases of postoperative periostomy leakage. Of the 22 neonates 16 were alive four months after surgery. Six neonates died of complications due to underlying disease. CONCLUSION: We concluded that gastrostomy and Nissen fundoplication are safe procedures and help parents give a better care to these children.INTRODUÇÃO: Neonatos com dano neurológico são freqüentemente incapazes de deglutir necessitando de gastrostomia para alimentação. Devido ao risco de refluxo grave, esse procedimento é associado à fundoplicatura. OBJETIVO: Avaliar a segurança e eficácia da gastrostomia com fundoplicatura Nissen em 22 neonatos com dificuldades de deglutição devido à lesão neurológica grave. MÉTODO: Todos os neonatos foram submetidos a um período inicial de alimentação por sonda nasogástrica e, após consentimento informado, foram submetidos a gastrostomia com fundoplicatura Nissen. RESULTADOS: Não houve complicações intra-operatórias significativas. Houve dois casos de vazamento pós-operatório da ostomia. Dos 22 neonatos, 16 estavam vivos 4 meses após a cirurgia. Seis neonatos morreram por complicações devido à doença de base. CONCLUSÃO: A gastrostomia com fundoplicatura Nissen é procedimento seguro e ajuda os pais a darem melhor cuidado a crianças com lesão neurológica

In silico modelling of drug–polymer interactions for pharmaceutical formulations

Selecting polymers for drug encapsulation in pharmaceutical formulations is usually made after extensive trial and error experiments. To speed up excipient choice procedures, we have explored coarse-grained computer simulations (dissipative particle dynamics (DPD) and coarse-grained molecular dynamics using the MARTINI force field) of polymer–drug interactions to study the encapsulation of prednisolone (log p = 1.6), paracetamol (log p = 0.3) and isoniazid (log p = −1.1) in poly(l-lactic acid) (PLA) controlled release microspheres, as well as the encapsulation of propofol (log p = 4.1) in bioavailability enhancing quaternary ammonium palmitoyl glycol chitosan (GCPQ) micelles. Simulations have been compared with experimental data. DPD simulations, in good correlation with experimental data, correctly revealed that hydrophobic drugs (prednisolone and paracetamol) could be encapsulated within PLA microspheres and predicted the experimentally observed paracetamol encapsulation levels (5–8% of the initial drug level) in 50 mg ml−1 PLA microspheres, but only when initial paracetamol levels exceeded 5 mg ml−1. However, the mesoscale technique was unable to model the hydrophilic drug (isoniazid) encapsulation (4–9% of the initial drug level) which was observed in experiments. Molecular dynamics simulations using the MARTINI force field indicated that the self-assembly of GCPQ is rapid, with propofol residing at the interface between micellar hydrophobic and hydrophilic groups, and that there is a heterogeneous distribution of propofol within the GCPQ micelle population. GCPQ–propofol experiments also revealed a population of relatively empty and drug-filled GCPQ particles

Amino Acid Precursor Supply in the Biosynthesis of the RNA Polymerase Inhibitor Streptolydigin by Streptomyces lydicus▿†

Biosynthesis of the hybrid polyketide-nonribosomal peptide antibiotic streptolydigin, 3-methylaspartate, is utilized as precursor of the tetramic acid moiety. The three genes from the Streptomyces lydicus streptolydigin gene cluster slgE1-slgE2-slgE3 are involved in 3-methylaspartate supply. SlgE3, a ferredoxin-dependent glutamate synthase, is responsible for the biosynthesis of glutamate from glutamine and 2-oxoglutarate. In addition to slgE3, housekeeping NADPH- and ferredoxin-dependent glutamate synthase genes have been identified in S. lydicus. The expression of slgE3 is increased up to 9-fold at the onset of streptolydigin biosynthesis and later decreases to ∼2-fold over the basal level. In contrast, the expression of housekeeping glutamate synthases decreases when streptolydigin begins to be synthesized. SlgE1 and SlgE2 are the two subunits of a glutamate mutase that would convert glutamate into 3-methylaspartate. Deletion of slgE1-slgE2 led to the production of two compounds containing a lateral side chain derived from glutamate instead of 3-methylaspartate. Expression of this glutamate mutase also reaches a peak increase of up to 5.5-fold coinciding with the onset of antibiotic production. Overexpression of either slgE3 or slgE1-slgE2 in S. lydicus led to an increase in the yield of streptolydigin