A widespread methylotroph acyl-homoserine lactone synthase produces a new quorum sensing signal that regulates swarming in Methylobacterium fujisawaense.

IMPORTANCE: Bacteria known as pink-pigmented facultative methylotrophs colonize many diverse environments on earth, play an important role in the carbon cycle, and in some cases promote plant growth. However, little is known about how these organisms interact with each other and their environment. In this work, we identify one of the chemical signals commonly used by these bacteria and discover that this signal controls swarming motility in the pink-pigmented facultative methylotroph Methylobacterium fujisawaense DSM5686. This work provides new molecular details about interactions between these important bacteria and will help scientists predict these interactions and the group behaviors they regulate from genomic sequencing information.

The effects of moderate alterations in adrenergic activity on acute appetite regulation in obese women: A randomised crossover trial.

BACKGROUND: Previous evidence has demonstrated that serum leptin is correlated with appetite in combination with, but not without, modest exercise. AIM: The present experiments investigated the effects of exogenous adrenaline and α/ß adrenoceptor blockade in combination with moderate exercise on serum leptin concentrations, appetite/satiety sensations and subsequent food intake in obese women. METHODS: A total of 10 obese women ((mean ± SEM), age: 50 (1.9) years, body mass index 36 (4.1) kg/m2, waist 104.8 (4.1) cm) participated in two separate, double-blind randomised experimental trials. Experiment 1: moderate exercise after α/ß adrenergic blocker (labetalol, 100 mg orally) versus moderate exercise plus placebo; experiment 2: adrenaline infusion for 20 minutes versus saline infusion. Appetite/satiety and biochemistry were measured at baseline, pre- and immediately post-intervention, then 1 hour post-intervention (i.e., before dinner). Food intake was assessed via ad libitum buffet-style dinner. RESULTS: No differences were found in appetite/satiety, subsequent food intake or serum leptin in any of the studies (experiment 1 or experiment 2). In experiment 1, blood glucose was higher (p < 0.01) and plasma free fatty acids lower (p = 0.04) versus placebo. In experiment 2, plasma free fatty acids (p < 0.05) increased after adrenaline versus saline infusion. CONCLUSIONS: Neither inhibition of exercise-induced adrenergic activity by combined α/ß adrenergic blockade nor moderate increases in adrenergic activity induced by intravenous adrenaline infusion affected acute appetite regulation.

Patterns of mortality in free-ranging California Condors (Gymnogyps californianus).

We document causes of death in free-ranging California Condors (Gymnogyps californianus) from the inception of the reintroduction program in 1992 through December 2009 to identify current and historic mortality factors that might interfere with establishment of self-sustaining populations in the wild. A total of 135 deaths occurred from October 1992 (the first post-release death) through December 2009, from a maximum population-at-risk of 352 birds, for a cumulative crude mortality rate of 38%. A definitive cause of death was determined for 76 of the 98 submitted cases, 70% (53/76) of which were attributed to anthropogenic causes. Trash ingestion was the most important mortality factor in nestlings (proportional mortality rate [PMR] 73%; 8/11), while lead toxicosis was the most important factor in juveniles (PMR 26%; 13/50) and adults (PMR 67%; 10/15). These results demonstrate that the leading causes of death at all California Condor release sites are anthropogenic. The mortality factors thought to be important in the decline of the historic California Condor population, particularly lead poisoning, remain the most important documented mortality factors today. Without effective mitigation, these factors can be expected to have the same effects on the sustainability of the wild populations as they have in the past.

In vitro metabolism of MK-0767 [(+/-)-5-[(2,4-dioxothiazolidin-5-yl)methyl]-2-methoxy-N-[[(4-trifluoromethyl) phenyl]methyl]benzamide], a peroxisome proliferator-activated receptor alpha/gamma agonist. I. Role of cytochrome P450, methyltransferases, flavin monooxygenases, and esterases.

The metabolism of MK-0767, (+/-)-5-[(2,4-dioxothiazolidin-5-yl)methyl]-2-methoxy-N-[[(4-trifluoromethyl) phenyl]methyl]benzamide, a thiazolidinedione (TZD)-containing peroxisome proliferator-activated receptor alpha/gamma agonist, was studied in liver microsomes and hepatocytes from humans and rat, dog, and rhesus monkey, to characterize the enzyme(s) involved in its metabolism. The major site of metabolism is the TZD ring, which underwent opening catalyzed by CYP3A4 to give the mercapto derivative, M22. Other metabolites formed in NADPH-fortified liver microsomes included the TZD-5-OH derivative (M24), also catalyzed by CYP3A4, and the O-desmethyl derivative (M28), whose formation was catalyzed by CYP2C9 and CYP2C19. Metabolite profiles from hepatocyte incubations were different from those generated with NADPH-fortified microsomal incubations. In addition to M22, M24, and M28, hepatocytes generated several S-methylated metabolites, including the methyl mercapto (M25), the methyl sulfoxide amide (M16), and the methyl sulfone amide (M20) metabolites. Addition of the methyl donor, S-adenosyl methionine, in addition to NADPH, to microsomal incubations enhanced the turnover and resulted in metabolite profiles similar to those in hepatocyte incubations. Collectively, these results indicated that methyltransferases played a major role in the metabolism of MK-0767. Using enzyme-specific inhibitors, it was concluded that microsomal thiol methyltransferases play a more important role than the cytosolic thiopurine methyltransferase. Baculovirus-expressed human flavin-containing monooxygenase 3, as well as CYP3A4, oxidized M25 to M16, whereas further oxidation of M16 to M20 was catalyzed mainly by CYP3A4. Esterases were involved in the formation of the methyl sulfone carboxylic acids, minor metabolites detected in hepatocytes.

A small molecule alpha4beta1/alpha4beta7 antagonist differentiates between the low-affinity states of alpha4beta1 and alpha4beta7: characterization of divalent cation dependence.

An alpha4beta1/alpha4beta7 dual antagonist, 35S-compound 1, was used as a model ligand to study the effect of divalent cations on the activation state and ligand binding properties of alpha4 integrins. In the presence of 1 mM each Ca2+/Mg2+, 35S-compound 1 bound to several cell lines expressing both alpha4beta1 and alpha4beta7, but 2S-[(1-benzenesulfonyl-pyrrolidine-2S-carbonyl)-amino]-4-[4-methyl-2S-(methyl-[2-[4-(3-o-tolyl-ureido)-phenyl]-acetyl]-amino) pentanoylamino]-butyric acid (BIO7662), a specific alpha4beta1 antagonist, completely inhibited 35S-compound 1 binding, suggesting that alpha4beta1 was responsible for the observed binding. 35S-Compound 1 bound RPMI-8866 cells expressing predominantly alpha4beta7 with a KD of 1.9 nM in the presence of 1 mM Mn2+, and binding was inhibited only 29% by BIO7662, suggesting that the probe is a potent antagonist of activated alpha4beta7. With Ca2+/Mg2+, 35S-compound 1 bound Jurkat cells expressing primarily alpha4beta1 with a KD of 18 nM. In contrast, the binding of 35S-compound 1 to Mn2+-activated Jurkat cells occurred slowly, reaching equilibrium by 60 min, and failed to dissociate within another 60 min. The ability of four alpha4beta1/alpha4beta7 antagonists to block binding of activated alpha4beta1 or alpha4beta7 to vascular cell adhesion molecule-1 or mucosal addressin cell adhesion molecule-1, respectively, or to 35S-compound 1 was measured, and a similar rank order of potency was observed for native ligand and probe. Inhibition of 35S-compound 1 binding to alpha4beta1 in Ca2+/Mg2+ was used to identify nonselective antagonists among these four. These studies demonstrate that alpha4beta1 and alpha4beta7 have distinct binding properties for the same ligand, and binding parameters are dependent on the state of integrin activation in response to different divalent cations.