Smoking is a major risk factor for several cardiovascular and pulmonary diseases, and it has also been associated with the loss of skeletal muscle mass and strength leading to sarcopenia. The aim of this is study is to analyze the effects of cigarette smoking on the diaphragm muscle histopathology of postmortem samples from patients without respiratory diseases. Diaphragm samples were stained with hematoxylin and eosin for histopathological analysis. Picrosirius stain was used to highlight the collagen fibers. Cigarette smokers had an increase of histopathological alterations as abnormal cytoplasm, abnormal fiber size and shape, and central nucleus. Additionally, smokers had an increase of collagen fibers on diaphragm muscle. Smoking may influence in a negatively fashion the diaphragm musculature.

Thirty male 20-months-old Wistar rats were divided into groups: IC – initial control (n = 6), FC – final control (n = 6), AC – anabolic hormone control (n = 6), ST - strength trained (n = 6) and STA - strength trained with anabolic hormone (n = 6). All groups were submitted to adaptation, familiarization and maximum load carrying test (MLCT). Strength training (6-8x / session with loads of 50 to 100% MLCT, 3x/week and pause of 120 seconds) was performed in ladder climbing for 15 weeks. The administration of testosterone (TP) was performed 2x/week (10 mg/kg) in animals in the AC and STA groups. After the experimental period, animals were euthanized and the tibial nerve and plantaris muscle removed and prepared for electron transmission and histochemistry. To compare the groups we used one-way ANOVA (post hoc Bonferroni), student's t-tests for pre vs post (dependent and independent variables) comparisons and significance level set at p ≤ 0.05. The following significant results were found: a) aging decreased the number of myelinated axon fibers; b) use of isolated TP increased the diameter of myelinated fibers, along with increased thickness of myelin sheath.; c) ST increased area of myelinated and unmyelinated fibers, together with the myelin sheath. These changes made it possible to increase the area occupied by myelinated fibers keeping their quantity and also reduce the interstitial space; d) association of anabolic steroid and ST increased the area of unmyelinated axons and thickness of the myelin sheath. Compared to ST, both strategies have similar results. However, Schwann cells increased significantly only in this strategy.

This study aimed to quantify training parameters and analyze the morphological response of aged muscles submitted to resistance training and anabolic steroids. Aged Wistar rats were divided into groups: C - initial control; CF - final control; CAS - control with anabolic steroid, RT - resistance training, and RTA - resistance training with anabolic steroid. Maximum carried load, absolute and relative loads increased significantly in RT and RTA. RTA demonstrated greater relative load than RT. Average total volume, total climbing volume, relative total volume, relative total climbing volume, and mean climbing volume were similar between groups RT and RTA. For soleus, CAS, RT, and RTA enlarged cross-sectional area of type I fibers and nuclear ratio. As for type II fibers, RTA was higher than C and CF. For plantaris, RT and RTA showed significant increases in myofibers type I compared to C and CF. For type II fibers, RTA showed a significant increase compared to C and CF. Regarding the nuclear ratio, RT and RTA showed a higher ratio than C, CF, and CAS. Our results demonstrated that both RT and RTA were not different among the analyzed morphological parameters. This fact can be explained by the absence of differences found in the training variables analyzed.

Sarcopenia is a progressive skeletal muscle disorder associated with aging, resulting in loss of muscle mass and function. It has been linked to inflammation, oxidative stress, insulin resistance, hormonal changes (i.e. alterations in the levels or activity of hormones which can occur due to a variety of factors, including aging, stress, disease, medication, and environmental factors), and impaired muscle satellite cell activation. The gut microbiome is also essential for muscle health, and supplements such as probiotics, prebiotics, protein, creatine, and betaalanine can support muscle growth and function while also promoting gut health. Chronic low-grade inflammation is a leading cause of sarcopenia, which can activate signaling pathways that lead to muscle wasting and reduce muscle protein synthesis. Insulin resistance, hormonal changes, and impaired muscle satellite cell activation contribute to sarcopenia, and high levels of fat mass also play a role in the pathogenesis of sarcopenia. Resistance exercise and dietary supplementation have been shown to be effective treatments for sarcopenia. In addition, a combination of resistance exercise and supplementation has been shown to have a more significant beneficial effect on anthropometric and muscle function parameters, leading to a decrease in sarcopenic state. Thus, understanding the relationship between the gut microbiome and muscle metabolism is crucial for developing new treatments for sarcopenia across age groups.

Dear Editor, The quality, efficiency, and speed of a quantitative analysis are critical factors in cytopathology. In this scenario, reliable and reproducible tools are needed to improve results in a shorter period,[1] mainly routine immunohistochemistry (IHC) slides and biomedical research. Histological experiments rely on visualization of results using staining techniques, due to the ability of light-absorbing dyes to selectively bind to molecules and complexes of interest, which may provide a quantitative analysis when combining computational techniques.[2] Thereby, color deconvolution can be addressed as a versatile tool in quantitative analysis as this method is able to split in channels the different dyes of a staining technique,[3] which allows analysis of the area fraction of the aimed structures. In [Fig. 1], we can see that the “color deconvolution” tool on ImageJ (National Institutes of Health, United States) allows unmixing brightfield images into channels representing the absorbance of the individual dyes. After splitting the channels, images can be turned into gray with the aid of the “threshold” tool to determine the structure area. Then, we can measure the “area fraction” of the stained structures in contrast with the white background. Using this method, it is possible to quantify the stained area of each field in a semi-automatic manner, which allows a greater flow of analysis. This simple and rapid technique to analyze the absorbance of different dyes in a quantitative manner has the potential to increase the flow of analysis in biomedical research. To corroborate with our presented toolkit, color deconvolution was previously used by researchers to study, e.g., hepatocellular carcinoma,[4] atherosclerotic lesions,[5] deep neural networks,[6] and skin layers.[7] These studies showed the versatility of this technique in both histochemistry and IHC as the brown color generated by 3,3′-diaminobenzidine from IHC can be separate from the original image and quantitatively analyzed to show the percentage of its stained structure. Additionally, this process of analysis can be addressed in the manuscripts as a supplementary material to show the image after color deconvolution. The growing availability of image digitization and bioinformatic technologies has driven the search for new ways of analyzing image datasets.[2] [8] [9] Thus, to have a reliable method to increase the speed of analysis is of paramount importance to conduct cytological studies in larger samples. In this sense, we hope that this toolkit may be a useful method in further histopathological studies. Article published online: 24 April 2023 © 2023. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/) Thieme Medical and Scientific Publishers Pvt. Ltd. A-12, 2nd Floor, Sector 2, Noida-201301 UP, India

Aging males have a decrease in testosterone levels, by which the testosterone treatment may influence in a negatively fashion the liver. Aim: This study aimed to analyze the effects of aging with or without testosterone administration on the liver components of animals. Methods: Wistar rats were divided into three groups: 20 months’ group (G20), 24 months’ group (G24), group treated with testosterone for 16 weeks (GT). All groups were sacrificed at 24 months except for G20 that was sacrificed at 20 months. Results: Aging and testosterone treatment alters the body weight (BW), liver weight (LW) and relative liver weight. Besides, testosterone increased the mitogen capacity of hepatocytes. Nonetheless, we reinforce the negative effects of testosterone on old animals’ liver as chronic hepatic congestion and/or cholestasis. In addition, we observed that testosterone plays an important role on hepatic glycogen stores. Conclusions: Our study showed many implications for the knowledge about the effects of aging with or without testosterone administration on old animals’ liver.