Anabolic effects of oral leucine-rich protein with and without β-hydroxybutyrate on muscle protein metabolism in a novel clinical model of systemic inflammation-a randomized crossover trial

BACKGROUND

β-lactoglobulin (BLG) stimulates muscle protein synthesis and β-hydroxybutyrate (BHB) inhibits muscle breakdown. Whether combining the 2 can additively attenuate disease-induced muscle loss is unknown.

OBJECTIVE

Based on previous observations of anticatabolic effects of protein and ketone bodies during inflammation, and using a novel model combining ongoing systemic inflammation, fasting, and immobilization, we tested whether the anticatabolic muscle response to oral amino acids is altered compared with control conditions, as well as whether coadministration of oral BHB and BLG further improves the muscle anabolic response. Muscle net balance (NBphe) was the primary outcome and intramyocellular signals were assessed.

METHODS

In a randomized crossover design, 8 young men underwent either preconditioning with LPS (prestudy day: 1 ng/kg, study day: 0.5 ng/kg) combined with a 36-h fast and bed rest to mimic catabolic inflammatory disease (CAT) or an overnight fast (control [CTR]) prior to isocaloric nutritional interventions on 3 occasions separated by ∼6 wk (range 42 to 83 d).

RESULTS

NBphe increased similarly upon all conditions (interaction P = 0.65). From comparable baseline rates, both Rdphe [muscle synthesis, median ratio (95% CI): 0.44 (0.23, 0.86) P = 0.017] and Raphe [muscle breakdown, median ratio (95% CI): 0.46 (0.27, 0.78) P = 0.005] decreased following BHB + BLG compared with BLG. BLG increased Rdphe more under CAT conditions compared with CTR (interaction P = 0.02). CAT increased inflammation, energy expenditure, and lipid oxidation and decreased Rdphe and anabolic signaling [mammalian target of rapamycin (mTOR) and eukaryotic translation initiation factor 4E-binding protein 1 (4EPB1) phosphorylation].

CONCLUSION

In contrast to our initial hypothesis, NBphe increased similarly following BLG during CAT and CTR conditions; CAT however, specifically stimulated the BLG-mediated increase in protein synthesis, whereas BHB coadministration did not affect NBphe, but distinctly dampened the BLG-induced increase in muscle amino acid fluxes thereby liberating circulating amino acids for anabolic actions elsewhere.

Impaired hepatic counterregulatory response to insulin-induced hypoglycemia in hepatic denervated pigs

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Hepatic denervation results in a blunted counterregulatory response during insulin-induced hypoglycemia.

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Fasting glucose concentration, glucose production and uptake are unaffected by hepatic denervation.

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Insulin action and extrahepatic glucose uptake are unaffected by hepatic denervation.

Objective

The liver reacts to hypoglycemia by increasing its glucose output. This response is assumed to depend both on glucose sensing at the liver and the brain, as well as efferent impulses from the brain to the liver. We tested the importance of this signaling pathway by studying the hepatic response to insulin-induced hypoglycemia in hepatic complete denervated pigs.

Materials/methods

Two weeks prior to the metabolic study, 36-kg pigs underwent either total hepatic denervation (DN; n = 12) or sham operation (sham; n = 12). On the metabolic study day, measurements were performed at baseline conditions and during a hypoglycemic hyperinsulinemic (5 mU/kg/min) clamp. Endogenous insulin and glucagon secretions were inhibited by somatostatin, and glucagon was replaced at baseline levels. Endogenous glucose production (EGP) and glucose utilization (Rd) were determined by [3-³H] glucose infusion.

Results

Baseline plasma concentrations of glucose, insulin, EGP and Rd did not differ significantly between the two groups of animals. During insulin infusion, the plasma glucose concentration was clamped at ~3 mmol/L in both groups of animals resulting in an increase in plasma concentrations of epinephrine and norepinephrine in sham pigs (both P < 0.05), while this effect was abolished in DN pigs. While insulin action (P = 0.09) and glucose utilization (P = 0.44) were similar, EGP was markedly decreased in the DN pigs (P < 0.05).

Conclusion

The findings indicate a blunted hepatic counterregulatory response to hypoglycemia following complete hepatic denervation. This implies that intact neural impulses to and from the liver are necessary to maintain the increase in EGP that protects the organism against hypoglycemia.

Zur Darstellung und Kristallstruktur PbZn(NCS)4 / Synthesis and Crystal Structure of PbZn(NCS)4

PbZn(NCS)4 is obtained from the binary compounds Pb(SCN)2 and Zn(NCS)2 with traces of water in an ultra-sound bath. The space group of the complex is Pn21a (standard: Pna21) with Z = 4. The structure consists of cis-connected octahedra 2 ∞[PbS2S4/2] forming two-dimensional layers. All SCN-groups are bound to Zn2+ via their N atoms. The resulting ZnN4 tetrahedra are arranged in the cavities formed by the PbS6 octahedra.

Impedanzmessungen an Tetraiodomercuraten/Impedance Spectroscopy of Tetraiodomercurates

As thermochromic compounds, tetraiodomercurates show phase transitions, which have been investigated by impedance spectroscopy. In the case of Ag2HgI4 and Cu2HgI4 we found clear changes of conductivity not present with HgI2. In all cases the main resistance is caused by the grain boundaries between the single crystals of the powder sample. Also diffusion in the double layer in front of the surface of the electrodes influences the spectra. Single crystal measurements of Hgl, show the different ionic mobilities along the various crystallographic directions.

Patients' participation in and evaluation of a follow-up program following intensive care

BACKGROUND

Patients' difficulties following critical illness and the willingness of intensive care units (ICU) to take an expanded responsibility during the recovery period have led to the development of different follow-up programs. The aim of this study was to explore and describe patients' participation in and evaluation of a follow-up program at a nurse-led clinic (NLC).

METHODS

Patients with a length of stay ≥72 h, discharged from the ICU, participated in a follow-up program based on three contacts, as a visit to the NLC, telephone contact, ward visit or as an indirect contact, during a 6-month period. A specially developed database recorded information regarding patients' participation and questionnaires were used to obtain patients' views of the follow-up program.

RESULTS

Of 96 study patients, 51% visited the NLC once or twice. These patients were younger (P<0.001) and had lower Acute Physiology and Chronic Health Evaluation II (P=0.017) compared with those who did not visit the clinic. The most common reason for not visiting the clinic was not enough strength, chiefly physical. In the evaluation, patients answered that they received advice and information, an opportunity to talk, increased knowledge and re-evaluated memories and experiences from the ICU stay. Patients appreciated the follow-up and expressed gratitude to the competent and obliging staff.

CONCLUSION

The current follow-up program, adjusted to individual patients' conditions and needs in terms of different types of contacts and continuity, was found to be of great value. Effects of the program other than the patient perspective are also relevant to evaluate.

The influence of ionic strength and pH on the aggregation properties of zinc-free insulin studied by static and dynamic laser light scattering

The aggregation properties of zinc-free insulin have been studied using static and dynamic light scattering. The aggregation has been investigated as a function of three parameters, the concentration of sodium chloride (in the range 10-100 mM), the pH value (in the range pH 7.5-10.5), and the insulin concentration (1.8-13.4 mg/mL). The measured homodyne autocorrelation function was used to determine the apparent mean hydrodynamic diameter as well as the apparent weight-averaged molar mass of the insulin species in solution. A method of data analysis was employed, which allows the separation of light scattering contributions from the insulin oligomers and from irrelevant macromolecules and possible impurities present in the sample solutions. Also, a simple phenomenological equilibrium model describing the association of oligomers of insulin is presented. One aspect of this model is that it makes it possible to determine weight average molar masses corrected for virial effects on the Rayleigh ratio. This was necessary because virial effects cannot be isolated and corrected for by dilution since this would change the equilibrium distribution of oligomers. The basis of the model is a positive contribution to Gibbs free energy from charge repulsion depending on the protein charge and the number of monomers in the oligomers, and an assumed constant negative contribution to Gibbs free energy arising from either an entropic gain or hydrogen bonding upon association. The equilibrium model gives a good description of both the apparent weight average molar masses and the apparent hydrodynamic diameters, when the effect of the insulin concentration is taken into account by including virial effects arising from charge-charge repulsion (Donnan effect). The result shows that the association of insulin as a function of pH and ionic strength can be described by an effective charge equal to the charge derived from proton titration reduced by the number of sodium ions binding to insulin. At the lowest pH and highest salt concentration (pH 7.5, 100 mM NaCl, 12 mg/mL insulin), the weight average molar mass is close to that of the hexamer, and at the highest pH and lowest salt concentration (pH 10.5, 10 mM NaCl, 1.9 mg/mL), the weight average molar mass is close to that of the monomer. In all cases, however, a distribution of oligomers is present with a relative Gaussian width of about 30%.(ABSTRACT TRUNCATED AT 400 WORDS)

Indirect determination of traces of thiosulphate by differential-pulse polarography

Two methods are reported for the indirect determination of thiosulphate down to ca. 0.02 microg/ml by differential-pulse polarography. Both methods involve prior oxidation of thiosulphate with iodine, either in acidic medium to tetrathionate or in alkaline medium to sulphate, whereby ultimately one and eight equivalents of iodate are obtained, respectively. The concentration of iodate in the resulting solution is then measured by differential-pulse polarography under optimum conditions. The average recovery for each method amounted to 100.1%, and the relative standard deviations were 1.3 and 1.4% for the two methods.