The quantitative analysis of muscle histomorphometry has been growing in importance in both research and clinical settings. Accurate and stringent assessment of myofibers’ changes in size and number, and alterations in the proportion of oxidative (type I) and glycolytic (type II) fibers is essential for the appropriate study of aging and pathological muscle, as well as for diagnosis and follow-up of muscle diseases. Manual and semi-automated methods to assess muscle morphometry in sections are time-consuming, limited to a small field of analysis, and susceptible to bias, while most automated methods have been only tested in rodent muscle. We developed a new macro script for Fiji-ImageJ to automatically assess human fiber morphometry in digital images of the entire muscle. We tested the functionality of our method in deltoid muscle biopsies from a heterogeneous population of subjects with histologically normal muscle (male, female, old, young, lean, obese) and patients with dermatomyositis, necrotizing autoimmune myopathy, and anti-synthetase syndrome myopathy. Our macro is fully automated, requires no user intervention, and demonstrated improved fiber segmentation by running a series of image pre-processing steps before the analysis. Likewise, our tool showed high accuracy, as compared with manual methods, for identifying the total number of fibers (r = 0.97, p < 0.001), fiber I and fiber II proportion (r = 0.92, p < 0.001), and minor diameter (r = 0.86, p < 0.001) while conducting analysis in ~ 5 min/sample. The performance of the macro analysis was maintained in pectoral and deltoid samples from subjects of different age, gender, body weight, and muscle status. The output of the analyses includes excel files with the quantification of fibers’ morphometry and color-coded maps based on the fiber’s size, which proved to be an advantageous feature for the fast and easy visual identification of location-specific atrophy and a potential tool for medical diagnosis. Our macro is reliable and suitable for the study of human skeletal muscle for research and for diagnosis in clinical settings providing reproducible and consistent analysis when the time is of the utmost importance.

Maintaining and improving the nutritional quality of foods during processing are the main market and industry concerns. Thus, research should focus on novel and sustainable ways for selecting the appropriate processing method that either increases or does not affect the nutrient content of foods. Thermal processing techniques such as extrusion cooking are widely used for producing breakfast cereals, snack foods, pasta, pet food, etc. Extrusion cooking is a continuous process that uses a combination of high-temperature, high-pressure, and high shear conditions in a short period of time, which results in molecular transformation and chemical reactions within the extruded products. Extrusion cooking brings on many biochemical changes such as denaturation of proteins, gelatinization of starch, lipid modifications, inactivation of microorganisms and enzymes, formation of volatile flavor components, and increase in soluble dietary fiber. Furthermore, extrusion cooking has the potential to improve the nutritional quality of the products by improving starch and protein digestibility and increasing the retention of bioactive compounds with antioxidant properties. Also, this highly efficient technology minimizes water pollution and energy consumption. This review aims to discuss the current information regarding changes in nutritional properties and bioactive compounds in cereals processed by extrusion cooking.

1,25 Dihydroxyvitamin D₃ (1,25(OH)₂D) increases intestinal Ca absorption when dietary Ca intake is low by inducing gene expression through the vitamin D receptor (VDR). 1,25(OH)₂D‐regulated Ca absorption has been studied extensively in the small intestine, but VDR is also present in the large intestine. Our goal was to determine the impact of large intestinal VDR deletion on Ca and bone metabolism. We used transgenic mice expressing Cre‐recombinase driven by the 9.5‐kb human caudal type homeobox 2 (CDX2) promoter to delete floxed VDR alleles from the caudal region of the mouse (CDX2‐KO). Weanling CDX2‐KO mice and control littermates were fed low (0.25%) or normal (0.5%) Ca diets for 7 weeks. Serum and urinary Ca, vitamin D metabolites, bone parameters, and gene expression were analyzed. Loss of the VDR in CDX2‐KO was confirmed in colon and kidney. Unexpectedly, CDX2‐KO had lower serum PTH (–65% of controls, p < 0.001) but normal serum 1,25(OH)₂D and Ca levels. Despite elevated urinary Ca loss (eightfold higher in CDX2‐KO) and reduced colonic target genes TRPV6 (–90%) and CaBPD_9k (–80%) mRNA levels, CDX2‐KO mice had only modestly lower femoral bone density. Interestingly, duodenal TRPV6 and CaBPD_9k mRNA expression was fourfold and threefold higher, respectively, and there was a trend toward increased duodenal Ca absorption (+19%, p = 0.076) in the CDX2‐KO mice. The major finding of this study is that large intestine VDR significantly contributes to whole‐body Ca metabolism but that duodenal compensation may prevent the consequences of VDR deletion from large intestine and kidney in growing mice. © 2015 American Society for Bone and Mineral Research.

Low dietary calcium (Ca) intake during growth limits peak bone mass but physiological adaptation can prevent this adverse effect. To assess the genetic control on the physiologic response to dietary Ca restriction (RCR), we conducted a study in 51 BXD lines fed either 0.5% (basal) or 0.25% (low) Ca diets from ages 4 to 12 weeks (n = 8/line/diet). Ca absorption (CaAbs), femur bone mineral density (BMD), and bone mineral content (BMC) were examined. ANCOVA with body size as covariate was used to detect significant line and diet main effects, and line‐by‐diet interactions. Body size–corrected residuals were used for linkage mapping and to estimate heritability (h²). Loci controlling the phenotypes were identified using composite interval mapping on each diet and for the RCR. h² of basal phenotypes (0.37–0.43) and their RCR (0.32–0.38) was moderate. For each phenotype, we identified multiple quantitative trait loci (QTL) on each diet and for the RCR. Several loci affected multiple traits: Chr 1 (88.3–90.6 cM, CaAbs, BMC), Chr 4 (45.8–49.2 cM, CaAbs, BMD, BMC), Chr 8 (28.6–31.6 cM, CaAbs, BMD, RCR), and Chr 15 (13.6–24 cM, BMD, BMC; 32.3–36 cM, CaAbs RCR, BMD). This suggests that gene clusters may regulate interdependent bone‐related phenotypes. Using in silico expression QTL (eQTL) mapping and bioinformatic tools, we identified novel candidates for the regulation of bone under Ca stress (Ext1, Deptor), and for the first time, we report genes modulating Ca absorption (Inadl, Sc4mol, Sh3rf1, and Dennd3), and both Ca and bone metabolism (Tceanc2, Tll1, and Aadat). Our data reveal gene‐by‐diet interactions and the existence of novel relationships between bone and Ca metabolism during growth. © 2015 American Society for Bone and Mineral Research.