Social dominance in monkeys: Lack of effect on ethanol self-administration during schedule induction.

Nonhuman primate models of alcohol use disorder (AUD) frequently utilize schedule-induced polydipsia to initiate ethanol drinking. Previous research has demonstrated that specific characteristics of drinking during the final phase of induction, in which monkeys consume 1.5 g/kg of ethanol per day, can predict whether monkeys become heavy or light drinkers when they subsequently have free access to ethanol (22 hours per day; Baker, Farro, Gonzales, Helms, & Grant, 2017; Grant et al., 2008). A monkey's position in the social dominance hierarchy is another factor associated with ethanol drinking in nonhuman primates; lower social status is associated with higher ethanol intakes. In the present study, characteristics of drinking during induction were measured in 12 male cynomolgus monkeys living in three established social groups (4 monkeys per group). All monkeys were induced to consume water, then increasing doses of ethanol (0.5, 1.0, and 1.5 g/kg) for 30 sessions per dose using a 300-s fixed-time schedule of food pellet delivery. Drinking sessions occurred five days per week and monkeys were group-housed on the other two days. Contrary to our hypothesis that subordinate monkeys would show characteristics of drinking during the last phase of induction that were predictive of later heavy drinking, no significant differences were observed between dominant and subordinate monkeys in any phase of induction. When ethanol availability was subsequently increased to 22 hours per day for 5 weeks, the intakes of subordinate- and dominant-ranked monkeys diverged, with higher intakes on average in subordinates. Several factors unique to the conditions of induction may have obscured any influence of social rank, including the limited duration of sessions and limited maximal ethanol intake. The data support the conclusion that the effects of social rank on ethanol consumption require unrestricted access to ethanol.

Temperature-dependent phase behavior and protein partitioning in giant plasma membrane vesicles.

Liquid-ordered (Lo) and liquid-disordered (Ld) phase coexistence has been suggested to partition the plasma membrane of biological cells into lateral compartments, allowing for enrichment or depletion of functionally relevant molecules. This dynamic partitioning might be involved in fine-tuning cellular signaling fidelity through coupling to the plasma membrane protein and lipid composition. In earlier work, giant plasma membrane vesicles, obtained by chemically induced blebbing from cultured cells, were observed to reversibly phase segregate at temperatures significantly below 37 degrees C. In this contribution, we compare the temperature dependence of fluid phase segregation in HeLa and rat basophilic leukemia (RBL) cells. We find an essentially monotonic temperature dependence of the number of phase-separated vesicles in both cell types. We also observe a strikingly broad distribution of phase transition temperatures in both cell types. The binding of peripheral proteins, such as cholera toxin subunit B (CTB), as well as Annexin V, is observed to modulate phase transition temperatures, indicating that peripheral protein binding may be a regulator for lateral heterogeneity in vivo. The partitioning of numerous signal protein anchors and full length proteins is investigated. We find Lo phase partitioning for several proteins assumed in the literature to be membrane raft associated, but observe deviations from this expectation for other proteins, including caveolin-1.

Firearms risk management in psychiatric care.

OBJECTIVE: This study sought to assess the effectiveness of a firearms risk management program. METHODS: A firearms risk management program, which included multidisciplinary assessment, treatment, and discharge planning, was developed and implemented among 46 civilly committed psychiatric inpatients at the Twin Valley Psychiatric System, a behavioral health organization of the Ohio Department of Mental Health. RESULTS: The research sample comprised mainly men who had personality disorders and histories of substance abuse and who had expressed an intent to use a firearm to commit suicide. On discharge, none of the patients had access to a firearm. Of the 16 patients who were hospitalized during the next 24 months, only five were noted to have threatened to harm themselves or others with a firearm or to have access to a firearm. CONCLUSIONS: Multidisciplinary and focused assessment, treatment, and discharge planning can be effective in neutralizing the risk of firearms use among psychiatric patients.

Additive hypocholesterolemic effect of psyllium and cholestyramine in the hamster: influence on fecal sterol and bile acid profiles.

Recent findings suggest that the effects of cholestyramine and psyllium in combination could be additive for cholesterol-lowering. We therefore examined the effect of both agents, alone and in combination, on lipoprotein cholesterol and neutral and acidic steroid excretion in the hamster. Animals (n = 8/group) were fed for 21 days, either a basal chow diet supplemented with 10% palm oil and 0.2% cholesterol, or one of four treatments consisting of the basal diet plus: 5.5% cellulose; 5% psyllium with 0.5% cellulose; 0.5% cholestyramine with 5% cellulose; or 5% psyllium with 0.5% cholestyramine. Psyllium and cholestyramine both had significant hypocholesterolemic effects, but in combination produced additive reductions in lipoprotein and hepatic cholesterol. Psyllium, cholestyramine, and the combination increased total bile acid excretion by 26%, 57%, and 79%, respectively. Psyllium affected only unconjugated bile acid excretion while cholestyramine also increased the excretion of conjugated and primary bile acids. Neither agent, nor the combination, affected fecal neutral sterol excretion. We conclude that, while both agents lower cholesterol by a mechanism of increased bile acid excretion, these studies indicate that psyllium does not bind bile acids in vivo and lend further support for the concomitant use of these agents for cholesterol-lowering.

Influence of a methanogenic flora on the breath H2 and symptom response to ingestion of sorbitol or oat fiber.

BACKGROUND AND OBJECTIVES: We investigated the possibility that a variant of the normal colonic flora, a high concentration of methanogens, influences the host's response to ingestion of nonabsorbable, fermentable materials. METHODS: To better evaluate symptomatic and breath H2 and methane (CH4) responses, subjects were placed on a basal diet (primarily rice and hamburger) that contained minimal amounts of nonabsorbable, fermentable substrate. A breath CH4/H2 ratio of greater or less than 1 on the second day of the basal diet was used to categorize subjects as high (N = 9) or low (N = 25) CH4 producers. After stabilization of the breath gas excretion (day 3 or 4 on the basal diet), the subjects ingested either sorbitol (8.8 g) or oat fiber (10.2 g). RESULTS: The low CH4 producers had a significantly higher (p < 0.05) breath H2 concentration than the high producers on the basal diet and after ingestion of sorbitol (27.1 +/- 2.7 ppm vs 15.8 +/- 3.6 ppm) or oat fiber (13.1 +/- 0.08 ppm vs 9.6 +/- 1.2 ppm). Low producers of methane reported significantly increased bloating and cramping after sorbitol ingestion and increased bloating after fiber ingestion, whereas high CH4 producers reported no significant increase in these symptoms. CONCLUSION: The presence of a methanogenic flora is associated with a reduced symptomatic response to ingestion of nonabsorbable, fermentable material in healthy subjects. Manipulation of the normal flora could be of therapeutic value in nonmethanogenic patients with irritable bowel syndrome.