Branched-chain amino-acids and albumin synthesis. Study with hepatocytes of normal and stressed rats

To evaluate the incorporation of branched-chain amino-acids (BCAA) in de novo synthesised albumin, a series of experiments was performed with cultured hepatocytes from normal (Group 1) and stressed rats (groups 2 and 3). Stress was induced by keeping the rats immobilised in a cold room for 6–8 h and assessed by the presence of bleeding ulcers in the stomach.The cells were cultured in a commercial synthetic medium (Ham F-12) poor in BCAA (5.74% of total) increasing amounts of BCAA were added to plates in groups 1 and 2 and equivalent quantities of nitrogen in the form of glycine were added to plates in group 3.In group 1, the increase in BCAA concentration from 22.74–210.8 mg/ml was followed by an increase in the albumin synthesis rate from 0.4–0.95 ug/mg cell prot/h.In group 2, the rise in BCAA was followed by a far greater increase from 0.3–5 ug/mg cell prot/h (at least 6 times normal levels).In group 3, only 20% of the increase in albumin synthesis obtained in group 2 was observed. These results suggest that in stress the liver increases the use of BCAA for protein synthesis, but the increase of nitrogen in the culture medium respresents only a low percentage of this effect.     

Long-term effects of TRH administration on food intake and body weight in the rat

The effect of long-term TRH administration through drinking water (0.2 mg/ml) on food and water intake and body weight has been studied in three groups of female rats: (1) thyroidectomized, (2) thyroidectomized receiving daily 250 micrograms/kg of L-T4, (3) sham-operated. Treatment with oral TRH for 30 days decreased body weight and increased food intake in sham-operated rats. No TRH effects on body weight or food consumption were observed in either of the other groups of thyroidectomized rats. TRH administration increased circulating T3 levels in sham-operated animals, but had no effects in either hypo- or hyperthyroid, thyroidectomized rats. It can be concluded that the TRH-induced increase on food intake is mediated through the pituitary-thyroid axis.     

Sexual dimorphism in hepatic lipids is associated with the evolution of metabolic status in mice

Ectopic lipid accumulation in the liver is implicated in metabolic disease in an age‐ and sex‐dependent manner. The role of hepatic lipids has been well established within the scope of metabolic insults in mice, but has been insufficiently characterized under standard housing conditions, where age‐related metabolic alterations are known to occur. We studied a total of 10 male and 10 female mice longitudinally. At 3, 7 and 11 months of age, non‐invasive ¹H‐magnetic resonance spectroscopy (¹H‐MRS) was used to monitor hepatic lipid content (HLC) and fatty acid composition in vivo, and glucose homeostasis was assessed with glucose and insulin challenges. At the end of the study, hepatic lipids were comprehensively characterized by nuclear magnetic resonance (NMR) and liquid chromatography‐mass spectrometric analyses of liver tissue samples. In males, HLC increased from 1.4 ± 0.1% at 3 months to 2.9 ± 0.3% at 7 months (p < 0.01) and 2.7 ± 0.3% at 11 months (p < 0.05), in correlation with fasting insulin levels (p < 0.01, r = 0.51) and parameters from the insulin tolerance test (ITT; p < 0.001, r = –0.69 versus area under the curve; p < 0.01, r = –0.57 versus blood glucose drop at 1 h post‐ITT; p < 0.01, r = 0.55 versus blood glucose at 3 h post‐ITT). The metabolic performance of females remained the same throughout the study, and HLC was higher than that of males at 3 months (2.7 ± 0.2%, p < 0.01), but comparable at 7 months (2.2 ± 0.2%) and 11 months (2.2 ± 0.1%). Strong sexual dimorphism in bioactive lipid species, including diacylglycerols (higher in males, p < 0.0001), phosphatidylinositols (higher in females, p < 0.001) and omega‐3 polyunsaturated fatty acids (higher in females, p < 0.01), was found to be in good correlation with metabolic scores at 11 months. Therefore, in mice housed under standard conditions, sex‐specific composition of bioactive lipids is associated with metabolic protection in females, whose metabolic performance was independent of hepatic cytosolic lipid content.     

Refining a personalized mHealth intervention to promote medication adherence among HIV+ methamphetamine users

Mobile health (mHealth) interventions to promote antiretroviral therapy (ART) adherence have shown promise; however, among persons living with HIV who abuse methamphetamine (MA), effective tailoring of content to match the expressed needs of this patient population may be necessary. This study aimed (1) to understand patient perspectives of barriers and facilitators of ART adherence among people with HIV who use MA, and (2) to obtain feedback on the thematic content of an mHealth intervention in order to tailor the intervention to this subgroup. Two separate focus groups, each with 10 HIV+/MA+ individuals, were conducted. Transcribed audio recordings were qualitatively analyzed to identify emergent themes. Inter-rater reliability of themes was high (mean Kappa = .97). Adherence barriers included MA use, misguided beliefs about ART adherence, memory and planning difficulties, social barriers and perceived stigma, and mental heath issues. Facilitators of effective ART adherence were cognitive compensatory strategies, promotion of well-being, health-care supports, adherence education, and social support. Additionally, the focus groups generated content for reminder text messages to be used in the medication adherence intervention. This qualitative study demonstrates the feasibility of using focus groups to derive patient-centered intervention content to address the health challenge at hand in targeted populations.