Persisters are bacteria that are highly tolerant to antibiotics due to their dormant state and are of clinical significance owing to their role in infections. Given that the population of persisters increases in biofilms and that cyclic diguanylate (c-di-GMP) is an intracellular signal that increases biofilm formation, we sought to determine whether c-di-GMP has a role in bacterial persistence....

For purposes of analysis of polynucleotides, it is desirable to have a phosphodiesterase, substantially free of 5-nucleotidase or other phosphatase activity. The presence of a phosphodiesterase in a wide variety of snake venoms was demonstrated by Gullan<l and Jackson (1). These venoms were found also to contain a potent 5-nucleotidase, but were free of alkaline phosphatase activity. Hurst and ...

Biochar as a soil amendment has been proposed for enhancing carbon sequestration and manure-borne hormone contaminant remediation. However, little is known about the ecological risk of biochar application in with contamination. This study investigated influence three manure-impacted soils contaminated estrogen hormones, natural 17β-estradiol synthesized 17α-ethinylestradiol microcosm experiment...

1. A phosphodiesterase that cleaves glycerophosphoinositol into glycerophosphate and inositol has been detected in rat tissues. 2. The enzyme requires Mg2+(Mn2+) and has a pH optimum of 7.7. 3. The richest sources of the enzyme are kidney and intestinal mucosa. In pancreas subcellular fractions it occurs largely in the microsomal fraction. 4. The enzyme is inhibited by excess substrate and by t...

A 43 year old woman presented with chronic eosinophilic pneumonia characterised by a high alveolar eosinophilic count, which allowed biochemical study of these cells. Alveolar eosinophils spontaneously produced high amounts of oxygen free radicals and exhibited an increased level of cyclic adenosine monophosphate (cAMP) phosphodiesterase (PDE) activity compared to blood eosinophils from control...

A histochemical demonstration of cyclic 3',5'-nucleotide phosphodiesterase in retinal photoreceptor outer segments is reported for the first time. The enzyme appears to be located on outer segment lamellae. It is not found in adjacent inner segment or nuclear regions. This histochemical localization is consistent with previously reported biochemical studies showing high phosphodiesterase activi...

Regulation of cyclic nucleotide concentrations in rod outer segments (Rana pipiens) has been further examined. The present studies show that illumination markedly diminishes the concentration of cyclic nucleotides in suspensions of photoreceptor membranes, but the locus of regulation is cyclic nucleotide phosphodiesterase (EC 3.1.4.c) (light-stimulated) and not adenylate cyclase. There is a mar...

The guanine nucleotides guanosine 5'[beta, gamma-imido]triphosphate (Gpp[NH]p), guanosine 5'-[gamma-thio]-triphosphate (GTP gamma S), GMP, GDP and GTP stimulated the hydrolysis of inositol phospholipids by a phosphodiesterase in rat cerebral cortical membranes. Addition of 100 microM-Gpp[NH]p to prelabelled membranes caused a rapid accumulation of [3H )inositol phosphates (less than 30 s) for u...

Phosphodiesterase inhibitors like sildenafil have already been shown to improve functional capacity and hemodynamics in the treatment of pulmonary arterial hypertension. Few studies address the effects of new phosphodiesterase inhibitors as tadalafil. We report a case of a patient with idiopathic pulmonary arterial hypertension in functional class IV (New York Heart Association) with significan...