Biosynthesis of fatty acids and triacylglycerols by 2,6,10,14-tetramethyl pentadecane-grown cells of Nocardia globerula 432.

Nocardia globerula strain 432 was able to synthesize triacylglycerols (TAG) during cultivation on 2,6,10,14-tetramethyl pentadecane (pristane) under nitrogen-limiting conditions. Within these cells, 4,8,12-trimethyl tridecanoic acid was the major fatty acid detected. Fatty acids with an odd number of carbon atoms and minor amounts of even-numbered fatty acids were also observed. Experiments carried out with acrylic acid, an inhibitor of beta-oxidation, suggested that odd-numbered fatty acids such as C15:0, C17:0 and 10-methyl C17:0 were synthesized de novo using propionyl-CoA, the beta-oxidation product, as precursor. Although N. globerula 432 incorporated mainly straight chain fatty acids into TAG, the branched fatty acid 4,8,12-trimethyl tridecanoic acid also appeared, to some extent, in the acylglycerols. The importance of TAG biosynthesis by pristane-grown cells of N. globerula strain 432 is discussed.

Gas-phase conversion of tetrazoles to oxadiazoles: isolation and characterization of the N-acylated intermediate.

The 5-substituted tetrazole ring was reacted in the gas phase with an acyl ion generated as the secondary reactive chemical ionization plasma in the mass spectrometer. The product ions obtained, among others, were proposed as the rearranged 2,5-disubstituted-1,3,4-oxadiazole nucleus. Its structure was demonstrated by comparison of the product ion spectrum of the 2,5-disubstituted-1,3,4-oxadiazole derivative obtained by condensed-phase reaction and the product ion spectrum of the oxadiazole derivative generated in situ by reaction of the 5-substituted tetrazole derivative with the acyl plasma. It was proposed that the mechanism of this transformation involved the presence of an acylated tetrazole intermediary, which could not be isolated in the condensed phase, followed by the rearrangement, with nitrogen loss, to afford the oxadiazole derivative. Under our conditions we were able to isolate the intermediate ion in the first field free region and demonstrate its structure by collision induced dissociation-tandem mass spectrometry.

Thermochemical aspects of proton transfer in the gas phase J.-F. Gal, P.-C. Maria and E. D. Raczynska. Journal of Mass Spectrometry, 2001; 36: 699-716.

The original article to which this Erratum refers was published in Journal of Mass Spectrometry 36 (7) 2001, 699-716.

[Idiopathic hypercalciuria: presentation of 471 cases] / Hipercalciúria idiopática: apresentação de 471 casos.

OBJECTIVE: To analyze the clinical history and evolution of children and adolescents with IH, emphasizing some of their peculiar features. METHODS: We followed 471 patients with IH at an outpatient clinic. Patients were submitted to the following protocol: abdominal X-ray, kidney and urinary tract ultrasonography; urinary ionogram, blood gas and biochemical analyses; 24-hour urine for measurement of calcium and other electrolytes and creatinine; urinalysis, urine culture and phase-contrast microscopy; second morning urine collected after fasting for measurement of calcium and creatinine. RESULTS: At the time of diagnosis, 6% of the patients were infants, 15% pre-school children, 55% school children, and 24% adolescents; 56% of them were boys. Clinical and laboratory findings were: 47% had hematuria and abdominal pain, 31% had isolated hematuria, 14% isolated abdominal pain, and 8% had urinary tract infection, nocturnal enuresis, suprapubic pain or urethralgia, or the frequency/urgency syndrome with urinary incontinence. Hypercalciuria was associated with urolithiasis in 56% of patients. There was association with hyperuricosuria in 18.5% of the cases, and hypocitraturia in 8.5% of the cases. Evolution was poor for 33% of the patients, with recurrence of nephrolithiasis, persistence of hematuria, and abdominal pain. CONCLUSIONS: IH must be diagnosed and treated with criteria in order to reduce consequences such as hematuria, abdominal pain, urinary stone formation and possible bone involvement. Signs and symptoms such as urgency and urinary incontinence, suprapubic pain and nocturnal enuresis may result from renal hyperexcretion of calcium.

Fisiopatología da síndrome nefrótica em crianças e adolescentes / Pathophysiology of nephrotic syndrome in children and adolescents

A Síndrome nefrótica (SN), caracterizada por proteinúria, hipoalbuminemia e edema, é a glomerulopatia mais comum em crianças. Apesar dos avanços, sua fisiopatologia permanece desconhecina. Considera-se que a SN é um distúrbio complexo e multifatorial, envolvendo agentes desencadeadores, alteraçôes genéticas e do sistema imune. Alteraçôes genéticas podem aumentar a susceptibilidade à SN ou provocar distúrbios de permeabilidade que se manifestam logo após o nascimento. Várias evidências sugerem também um papel significativo do sistema imne na fisiopatologia dessa doença, com uma aparente resposta anormal dos linfócitos T, Participaçâo de citocinas e quimiocinas, com destaque para o TGFß. Outros echaos sugerem a existência de algum fator circulante de permeabilidade, provavelmente derivado do sistema imune, relacionado às recidivas pós-transplante. O estudo mais aprofundado da fisiopatología da SN poderia proporiconar o desemvolvimiento de fármacos com maior respecificidade e menos efectos adversos