Soluble Whey Protein Hydrolysate Ameliorates Muscle Atrophy Induced by Immobilization via Regulating the PI3K/Akt Pathway in C57BL/6 Mice.

Sarcopenia, a loss of skeletal muscle mass and function, is prevalent in older people and associated with functional decline and mortality. Protein supplementation is necessary to maintain skeletal muscle mass and whey protein hydrolysates have the best nutrient quality among food proteins. In the first study, C57BL/6 mice were subjected to immobilization for 1 week to induce muscle atrophy. Then, mice were administered with four different whey protein hydrolysates for 2 weeks with continuous immobilization. Among them, soluble whey protein hydrolysate (WP-S) had the greatest increase in grip strength, muscle weight, and cross-sectional area of muscle fiber than other whey protein hydrolysates. To investigate the molecular mechanism, we conducted another experiment with the same experimental design. WP-S significantly promoted the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway and inhibited the PI3K/Akt/forkhead box O (FoxO) pathway. In addition, it increased myosin heavy chain (MyHC) expression in both the soleus and quadriceps and changed MyHC isoform expressions. In conclusion, WP-S attenuated muscle atrophy induced by immobilization by enhancing the net protein content regulating muscle protein synthesis and degradation. Thus, it is a necessary and probable candidate for developing functional food to prevent sarcopenia.

Retinal Nerve Fiber Layer Thickness in Various Retinal Diseases.

SIGNIFICANCE: Peripapillary retinal nerve fiber layer (RNFL) thickness measurements may be influenced by the range and severity of lesions that are observed distinctively in each retinal disease. PURPOSE: We investigated the effects of various macular (central serous chorioretinopathy, macular hole, epiretinal membrane, wet age-related macular degeneration) and retinal vascular (branch retinal vein occlusion, central retinal vein occlusion, diabetic macular edema) diseases on peripapillary RNFL thickness measurements using spectral-domain optical coherence tomography. METHODS: Six hundred thirty-one eyes from 464 patients with various retinal diseases and 167 controls of similar age were included in this retrospective study. Using spectral-domain optical coherence tomography, we measured the thickness of the macula and the RNFL in both various retinal disease eyes and normal control eyes. Four sectorial and average RNFL thicknesses were compared between each disease and age-matched control eyes. The macular thicknesses were also compared. RESULTS: In the macular disease group, superior (P = .033) and temporal (P = .024) quadrant RNFL thicknesses of central serous chorioretinopathy and temporal (P < .001) quadrant RNFL thicknesses of epiretinal membrane were greater than the age-matched control eyes. No RNFL measurements in macular hole or wet age-related macular degeneration differed significantly from the controls. In the retinal vascular disease group, all sectorial and average RNFL thicknesses of diabetic macular edema and central retinal vein occlusion were greater than those of the controls (all P < .05). In branch retinal vein occlusion, superior (P = .012) and temporal (P < .001) quadrant RNFL thicknesses were greater than those of the controls. CONCLUSIONS: Peripapillary RNFL thickness measurements may be influenced by the range and severity of lesions that are observed distinctively in each retinal disease. It also appeared that macular disease had a local effect on RNFL thickness, whereas retinal vascular disease had a diffuse effect on RNFL thickness.

Repeatability of ganglion cell-inner plexiform layer thickness measurements using spectral-domain OCT in branch retinal vein occlusion.

PURPOSE: To analyze the repeatability of thickness measurements of the central macula, ganglion cell-inner plexiform layer (GC-IPL), and retinal nerve fiber layer (RNFL) using spectral-domain optical coherence tomography (SD-OCT) before and after treatment of macular edema in branch retinal vein occlusion (BRVO). METHODS: We analyzed patients with BRVO who visited our retinal clinic. The repeatability of the thickness measurements were compared using the intraclass correlation coefficient (ICC) and coefficient of variation (COV) of affected versus normal fellow eyes. RESULTS: The average thicknesses of the central macula, RNFL, and GC-IPL were 371.28 µm, 105.60 µm, and 61.88 µm, respectively, in affected eyes with macular edema before treatment, and the ICCs were 0.978, 0.919, and 0.705, respectively. The average thicknesses were 244.98 µm, 96.70 µm, and 82.70 µm, respectively, in affected eyes without macular edema after treatment, and the ICCs were 0.999, 0.975, and 0.928, respectively. After resolution of macular edema, the average thickness of the GC-IPL increased, whereas that of the central macula and RNFL significantly decreased (P < 0.05); all of the ICCs increased compared to pretreatment values. In normal fellow eyes, the average thicknesses were 250.98 µm, 93.50 µm, and 83.84 µm, respectively, and the ICCs were 0.996, 0.995, and 0.994, respectively. CONCLUSIONS: After treatment of macular edema, the repeatability and thickness of the GC-IPL increased, along with reduction in the central macular thickness. This resulted from auto-segmentation errors following macular contour changes and unstable gazes of the patients due to decreased visual acuities in BRVO with macular edema.