Nuclear magnetic resonance studies of the regulation of the pentose phosphate pathway

The goal of this work is to investigate the potential for and limitations of in vivo nuclear magnetic resonance (NMR) spectroscopy for quantitation of glucose flux through the pentose phosphate pathway (shunt). Interest in the shunt is motivated by the possibility that its activity may be greatly increased in cancer and in the pathological states of cardiac and cerebral ischemia. The ability to dynamically monitor flux through the pentose shunt can give new knowledge about metabolism in pathological states. {sup 13}C NMR spectroscopy was used to monitor shunt activity by determination of the ratios of ({sup 13}C-4) to ({sup 13}C-5)-glutamate, ({sup 13}C-3) to ({sup 13}C-2)-alanine or ({sup 13}C-3) to ({sup 13}C-2)-lactate produced when ({sup 13}C-2)-glucose is infused. These methods provide measures of the effect of oxidative stresses on shunt activity in systems ranging from cell free enzyme-substrate preparations to cell suspensions and whole animals. In anaerobic cell free preparations, the fraction of glucose flux through the shunt was monitored with a time resolution of 3 minutes. This work predicts the potential for in vivo human studies of pentose phosphate pathway activity based on the mathematical simulation of the {sup 13}C fractional enrichments of C4 and C5-glutamate as a function of shunt activity and on the signal-to- noise ratio acquired in {sup 13}C NMR human studies from the current literature

Subtype analysis of Blastocystis sp. isolates from asymptomatic individuals in an urban community in the Philippines

Blastocystis sp. is a commonly reported enteric protistan parasite in faecal specimens with a worldwide distribution afflicting both humans and a wide range of animals. The aim of this study is to characterize the subtypes (STs) of Blastocystis sp. isolates from asymptomatic individuals in an urban community in Pateros, Metro Manila, Philippines. The 600-bp small subunit ribosomal RNA (SSU rRNA) barcoding region of Blastocystis sp. isolates was amplified and sequenced using the primers RD5 and BhRDr. Subtypes were identified by uploading the sequences onto the Basic Local Alignment and Search Tool (BLAST) websites, the Blastocystis Subtype (18S) and Sequence Typing (MLST) Database and by construction of a phylogenetic tree. Twenty-nine (29) out of 35 individuals were detected positive for Blastocystis sp. ST3 is the most common among the three STs detected (65.5%), followed by ST1 (31.0%) and ST4 (3.44%). This study showed that DNA barcoding can serve as a helpful tool to investigate the diversity of Blastocystis sp. in the Philippines