Short-term effects of a "health-at-every-size" approach on eating behaviors and appetite ratings

Objective: To assess the effects of a “Health‐At‐Every‐Size” (HAES) intervention on eating behaviors and appetite ratings in 144 premenopausal overweight women. Research Methods and Procedures: Women were randomly assigned to one of the 3 groups: HAES group, social support (SS) group, and control group (N = 48 in each group). Interventions were conducted over a 4‐month period, and measurements were taken before and after this period. Eating behaviors (cognitive dietary restraint, disinhibition, and susceptibility to hunger) were evaluated by the Three‐Factor Eating Questionnaire. Appetite ratings (desire to eat, hunger, fullness, and prospective food consumption) were assessed by visual analogue scales before and after a standardized breakfast. Results: More important decreases in susceptibility to hunger and external hunger were observed in the HAES group when compared with the SS group (p = 0.05, for susceptibility to hunger) and the control group (p = 0.02 and p = 0.005, for susceptibility to hunger and external hunger, respectively). In addition, women from the HAES group had more important decreases in postprandial area under the curve for desire to eat (p = 0.02) and hunger (p = 0.04) when compared with the control group. The change in the desire to eat noted in the HAES group was also different from the one observed in SS group (p = 0.02). Women from the HAES group experienced significant weight loss at 4 months (?1.6 ± 2.5 kg, p < 0.0001), which did not differ significantly from the SS and control groups (p = 0.09). An increase in flexible restraint was significantly related to a greater weight loss in both HAES and SS groups (r = ?0.39, p < 0.01; and r = ?0.37, p < 0.05, respectively). A decrease in habitual susceptibility to disinhibition was also associated with a greater weight loss in HAES and control groups (r = 0.31, p < 0.05; and r = 0.44, p < 0.05, respectively). Discussion: These results suggest that a HAES intervention could have significant effects on eating behaviors and appetite ratings in premenopausal overweight women, when compared with an SS intervention or a control group.     

An oxidized metabolite of linoleic acid increases intracellular calcium in rat adrenal glomerulosa cells

EKODE, an epoxy-keto derivative of linoleic acid, was previously shown to stimulate aldosterone secretion in rat adrenal glomerulosa cells. In the present study, we investigated the effect of exogenous EKODE on cytosolic [Ca(2+)] increase and aimed to elucidate the mechanism involved in this process. Through the use of the fluorescent Ca(2+)-sensitive dye Fluo-4, EKODE was shown to rapidly increase intracellular [Ca(2+)] ([Ca(2+)](i)) along a bell-shaped dose-response relationship with a maximum peak at 5 microM. Experiments performed in the presence or absence of Ca(2+) revealed that this increase in [Ca(2+)](i) originated exclusively from intracellular pools. EKODE-induced [Ca(2+)](i) increase was blunted by prior application of angiotensin II, Xestospongin C, and cyclopiazonic acid, indicating that inositol trisphosphate (InsP(3))-sensitive Ca(2+) stores can be mobilized by EKODE despite the absence of InsP(3) production. Accordingly, EKODE response was not sensitive to the phospholipase C inhibitor U-73122. EKODE mobilized a Ca(2+) store included in the thapsigargin (TG)-sensitive stores, although the interaction between EKODE and TG appears complex, since EKODE added at the plateau response of TG induced a rapid drop in [Ca(2+)](i). 9-oxo-octadecadienoic acid, another oxidized derivative of linoleic acid, also increases [Ca(2+)](i), with a dose-response curve similar to EKODE. However, arachidonic and linoleic acids at 10 microM failed to increase [Ca(2+)](i) but did reduce the amplitude of the response to EKODE. It is concluded that EKODE mobilizes Ca(2+) from an InsP(3)-sensitive store and that this [Ca(2+)](i) increase is responsible for aldosterone secretion by glomerulosa cells. Similar bell-shaped dose-response curves for aldosterone and [Ca(2+)](i) increases reinforce this hypothesis.     

Plasma kinetics of VLDL and HDL apoC-I in normolipidemic and hypertriglyceridemic subjects

ApoC-I has several different lipid-regulating functions including, inhibition of receptor-mediated uptake of plasma triglyceride-rich lipoproteins, inhibition of cholesteryl ester transfer activity, and mediation of tissue fatty acid uptake. Since little is known about the rate of production and catabolism of plasma apoC-I in humans, the present study was undertaken to determine the plasma kinetics of VLDL and HDL apoC-I using a primed constant (12 h) intravenous infusion of deuterium-labeled leucine. Data were obtained for 14 subjects: normolipidemics (NL, n = 4), hypertriglyceridemics (HTG, n = 4) and combined hyperlipidemics (CHL, n = 6). Plasma VLDL triglyceride (TG) levels were 0.59 +/- 0.03, 4.32 +/- 0.77 (P < 0.01 vs. NL), and 2.20 +/- 0.39 mmol/l (P < 0.01 vs. NL), and plasma LDL cholesterol (LDL-C) levels were 2.34 +/- 0.22, 2.48 +/- 0.26, and 5.35 +/- 0.48 mmol/l (P < 0.01 vs. NL), respectively. HTG and CHL had significantly (P < 0.05) increased levels of total plasma apoC-I (12.5 +/- 1.2 and 12.4 +/- 1.3 mg/dl, respectively) versus NL (7.9 +/- 0.6 mg/dl), due to significantly (P < 0.01) elevated levels of VLDL apoC-I (5.8 +/- 0.8 and 4.5 +/- 0.8 vs. 0.3 +/- 0.1 mg/dl). HTG and CHL also had increased rates of VLDL apoC-I transport (i.e., production) versus NL: 2.29 +/- 0.34 and 3.04 +/- 0.53 versus 0.24 +/- 0.11 mg/kg.day (P < 0.01), with no significant change in VLDL apoC-I residence times (RT): 1.16 +/- 0.12 versus 0.69 +/- 0.06 versus 0.74 +/- 0.17. Although HDL apoC-I concentrations were not significantly lower in HTG and CHL versus NL, HDL apoC-I rates of transport were inversely related to plasma and VLDL-TG levels (r = -0.63 and -0.62, respectively, P < 0.05). Our results demonstrate that increased levels of plasma and VLDL apoC-I in hypertriglyceridemic subjects (with or without elevated LDL-C levels) are associated with increased levels of plasma VLDL apoC-I production.     

Emerson enhancement of carbon fixation but not of acetylene reduction (nitrogenase activity) in Anabaena cylindrica

Summary Enhancement of carbon fixation was demonstrated in the bluegreen alga, Anabaena cylindrica, grown in either aerobic or microaerobic conditions. Under identical conditions no enhancement of acetylene reduction was observed. Light absorbed by photosystem I supported relatively more acetylene reduction than carbon fixation. No competition between the two processes was observed under light-limiting conditions. The findings suggest that carbon fixation and acetylene reduction may depend on different pools of reductant and ATP. When aerobically grown cells were placed in the dark or at limiting light intensities, acetylene reduction was higher in air than under argon. In contrast, carbon fixation was lower in air than in argon.     

The differential regulation of aldosterone output in hamster adrenal by angiotensinII and adrenocorticotropin.

Aldosterone was isolated from hamster adrenal cells and was identified by high performance liquid chromatography and thermospray mass spectroscopy analysis. Basal outputs from adrenal cell suspensions were of the same order of magnitude, 8.4 ± 1.9 ng and 8.0 ± 0.7 ng/2 h/50,000 cells, for aldosterone and corticosteroid, respectively. The outputs of aldosterone and corticosteroid increased with K⁺ concentrations to reach maxima of 3.3- and 1.6-fold at 10 meq/l of K⁺. Angiotensin_II (A_II) produced dose-dependent increases in aldosterone and corticosteroid outputs with maxima of 3- and 4-fold, respectively. In contrast, ACTH induced relatively no changes in aldosterone output, whereas dose-dependent increases in corticosteroid output were found. In time study experiments, with 10⁻⁸ M A_II, aldosterone and corticosteroid outputs were maximally increased after 1 h (6-fold) and 3 h (1.8-fold), respectively. At 10⁻⁸ M, ACTH had a small stimulatory effect on aldosterone output after 6 h, whereas it provoked a gradual increase in corticosteroid output (up to 7-fold after 8 h of incubation). The effects of A_II and ACTH on adrenal cytochrome P-450_11β involved in the last steps of aldosterone formation were evaluated by c combined in vivo andin vitro experiments. The P-450_11β mRNA level was increased by a low sodium intake but not by a 24 h ACTH stimulus. These results taken together indicate that ACTH and A_II differentially regulate P-450_11β. It is postulated that these two regulatory peptides regulate the hamster adrenal steroidogenesis by different P-450 genes.     

PAC1 receptor activation by PACAP-38 mediates Ca2+ release from a cAMP-dependent pool in human fetal adrenal gland chromaffin cells

Previous studies have shown that human fetal adrenal gland from 17- to 20-week-old fetuses expressed pituitary adenylate cyclase-activating polypeptide (PACAP) receptors, which were localized on chromaffin cells. The aim of the present study was to identify PACAP receptor isoforms and to determine whether PACAP can affect intracellular calcium concentration ([Ca(2+)](i)) and catecholamine secretion. Using primary cultures and specific stimulation of chromaffin cells, we demonstrate that PACAP-38 induced an increase in [Ca(2+)](i) that was blocked by PACAP (6-38), was independent of external Ca(2+), and originated from thapsigargin-insensitive internal stores. The PACAP-triggered Ca(2+) increase was not affected by inhibition of PLC beta (preincubation with U-73122) or by pretreatment of cells with Xestospongin C, indicating that the inositol 1,4,5-triphosphate-sensitive stores were not mobilized. However, forskolin (FSK), which raises cytosolic cAMP, induced an increase in Ca(2+) similar to that recorded with PACAP-38. Blockage of PKA by H-89 or (R(p))-cAMPS suppressed both PACAP-38 and FSK calcium responses. The effect of PACAP-38 was also abolished by emptying the caffeine/ryanodine-sensitive Ca(2+) stores. Furthermore, treatment of cells with orthovanadate (100 microm) impaired Ca(2+) reloading of PACAP-sensitive stores indicating that PACAP-38 can mobilize Ca(2+) from secretory vesicles. Moreover, PACAP induced catecholamine secretion by chromaffin cells. It is concluded that PACAP-38, through the PAC(1) receptor, acts as a neurotransmitter in human fetal chromaffin cells inducing catecholamine secretion, through nonclassical, recently described, ryanodine/caffeine-sensitive pools, involving a cAMP- and PKA-dependent phosphorylation mechanism.     

Transdifferentiation of Mature Cortical Cells to Functional Abscission Cells in Bean

Abscission explants of bean (Phaseolus vulgaris L.) were treated with ethylene to induce cell separation at the primary abscission zone. After several days of further incubation of the remaining petiole in endogenously produced ethylene, the distal two-thirds of the petiole became senescent, and the remaining (proximal) portion stayed green. Cell-to-cell separation (secondary abscission) takes place precisely at the interface between the senescing yellow and the enlarging green cells. The expression of the abscission-associated isoform of β-1,4-glucanhydrolase, the activation of the Golgi apparatus, and enhanced vesicle formation occurred only in the enlarging cortical cells on the green side. These changes were indistinguishable from those that occur in normal abscission cells and confirm the conversion of the cortical cells to abscission-type cells. Secondary abscission cells were also induced by applying auxin to the exposed primary abscission surface after the pulvinus was shed, provided ethylene was added. Then, the orientation of development of green and yellow tissue was reversed; the distal tissue remained green and the proximal tissue yellowed. Nevertheless, separation still occurred at the junction between green and yellow cells and, again, it was one to two cell layers of the green side that enlarged and separated from their senescing neighbors. Evaluation of Feulgen-stained tissue establishes that, although nuclear changes occur, the conversion of the cortical cell to an abscission zone cell is a true transdifferentiation event, occurring in the absence of cell division.