To understand how S-adenosylmethionine (SAM) concentrations fluctuate in normal and cancerous cells, particularly normal and cancerous liver cells, we have developed a novel real-time immunoassay to simultaneously measure methionine adenosyltransferase (MAT) activity and SAM levels. This method integrates the MAT-catalyzed reaction of L-Met and ATP to produce SAM and a highly sensitive immunoas...

The S-adenosylmethionine-1 (SAM-I) riboswitch mediates expression of proteins involved in sulfur metabolism via formation of alternative conformations in response to binding by SAM. Models for kinetic trapping of the RNA in the bound conformation require annealing of nonadjacent mRNA segments during a transcriptional pause. The entropic cost required to bring nonadjacent segments together shoul...

The shoot apical meristem (SAM) ensures continuous plant growth and organogenesis. In LD 30 °C, plants lacking AtFTSH4, an ATP-dependent mitochondrial protease that counteracts accumulation of internal oxidative stress, exhibit a puzzling phenotype of premature SAM termination. We aimed to elucidate the underlying cellular and molecular processes that link AtFTSH4 with SAM arrest. We studied At...

Severe necrotizing pancreatitis occurs in young female mice fed a choline-deficient and ethionine-supplemented (CDE) diet. Although the mechanism of the pancreatitis is unknown, one consequence of this diet is depletion of hepatic S-adenosylmethionine (SAM). SAM formation is catalyzed by methionine adenosyltransferases (MATs), which are encoded by liver-specific (MAT1A) and non-liver-specific (...

The relationship between the El Niño Southern Oscillation (ENSO) and the Southern Hemisphere Annular Mode (SAM) is examined, with the goal of understanding how various strong SAM events modulate the ENSO teleconnection to the South Pacific (45 –70 S, 150 – 70 W). The focus is on multi-month, multi-event variations during the last 50 years. A significant (p \ 0.10) relationship is observed, most...

BACKGROUND The quality of care for asthma remains suboptimal. Compliance with guidelines remains low, but improved adherence to guidelines may increase the quality of care. but. We conducted a trial to determine whether group Self-Assessment Module (SAM) activities led by a facilitator and conducted as part of Maintenance of Certification for Family Physicians (MC-FP) would increase knowledge o...

Perioperative echocardiography, especially transesophageal echocardiography, is of paramount importance in evaluating and managing refractory hypotension, a potential cause of which is systolic anterior motion (SAM) of anterior mitral leaflet. Dynamically moving anterior mitral valve leaflet towards the left ventricular outflow tract (LVOT) is described as SAM. Although SAM was initially observ...

Residues Tyr59, Gly78, Ser79, Met103, Gln107, Ile136 and Glu137 in human arsenic (+3 oxidation state) methyltransferase (hAS3MT) were deduced to form a potential hydrogen bond network around S-adenosylmethionine (SAM) from the sequence alignment between Cyanidioschyzon merolae arsenite S-adenosylmethyltransferase (CmArsM) and hAS3MT. Herein, seven mutants Y59A, G78A, S79A, M103A, Q107A, I136A a...

Shoot apical meristem (SAM) domes derived from five different outdoor and in vitro sources of juvenile and mature Eucalyptus urophylla x Eucalyptus grandis akin genotypes were compared. Overall measurements of SAM dome height H and diameter D ranged from 2 to 35 μm and 20 to 80 μm, notwithstanding significant differences according to the various physiological origins of plant material investiga...

Systolic anterior motion (SAM) of the mitral valve (MV) can be a life-threatening condition. The SAM can result in severe left ventricular outflow tract obstruction and/or mitral regurgitation and is associated with an up to 20% risk of sudden death (which is substantially lower in hypertrophic cardiomyopathy (HCM)). The mechanisms of SAM are complex and depend on the functional status of the v...