Muscle Tissue Samples Research Articles

Effects on Bone and Muscle upon Treadmill Interval Training in Hypogonadal Male Rats.

Testosterone deficiency in males is linked to various pathological conditions, including muscle and bone loss. This study evaluated the potential of different training modalities to counteract these losses in hypogonadal male rats. A total of 54 male Wistar rats underwent either castration (ORX, n = 18) or sham castration (n = 18), with 18 castrated rats engaging in uphill, level, or downhill interval treadmill training. Analyses were conducted at 4, 8, and 12 weeks postsurgery. Muscle force of the soleus muscle, muscle tissue samples, and bone characteristics were analyzed. No significant differences were observed in cortical bone characteristics. Castrated rats experienced decreased trabecular bone mineral density compared to sham-operated rats. However, 12 weeks of training increased trabecular bone mineral density, with no significant differences among groups. Muscle force measurements revealed decreased tetanic force in castrated rats at week 12, while uphill and downhill interval training restored force to sham group levels and led to muscle hypertrophy compared to ORX animals. Linear regression analyses showed a positive correlation between bone biomechanical characteristics and muscle force. The findings suggest that running exercise can prevent bone loss in osteoporosis, with similar bone restoration effects observed across different training modalities.

Bioaccumulation and health risk assessment of trace metal contamination in the musculature of the trahira fish (Hoplias malabaricus) from two neotropical rivers in southeastern Brazil

BackgroundFish are an important source of nutrition for humans. Artisanal fishing plays a fundamental role in Brazil fish production. In Brazil, the unrestrained increase, diffusion, and little importance for environmental causes of other economic activities, such as the agricultural industry, has caused irreparable damage, leading to the contamination of water bodies. Among the countless pollutants that reach water bodies, trace metals are extremely problematic. Here, we evaluated the bioaccumulation and health risk of trace metal contamination in the musculature of the trahira fish (Hoplias malabaricus), collected from two rivers in southeastern Brazil. MethodsDuring the period from May 2017 to November 2019, 90 fish were collected, 45 from each river. River water samples were also taken during the same collection periods. From fish, muscle tissue samples were taken, and together with river water samples, analyzed for the recovery of trace metals (Al, Cr, Mn, Fe, Ni, Cu, As, Cd, and Pb) through the technique of Inductively Coupled Plasma Mass Spectrometry (ICP-MS). ResultsIn general, fish as well as the waters of the Jacaré-Guaçú River had higher concentrations of metals. The elements Al, Cr and Cd stood out from the others analyzed metals for having a hazard index (HQ) above 1 (Al), for being up to 10 times above the concentrations allowed by Brazilian legislation (Cr) and for having a high bioconcentration factor (Cd), indicating a biomagnification process through the food chain. ConclusionIn general, trace metal concentrations in the waters and fish of the Jacaré‐Guaçú were higher than in the Jacaré-Pepira, which shows that the Jacaré‐Guaçú is the one that suffers more anthropogenic action between the two rivers. In addition, some elements such as Al, Cr and Cd, due to its high concentrations, should receive some attention as they can pose risks to the health of fish, which can jeopardize the survival of their populations, and especially to humans who use these animals as a food source.

Metal Levels in Serranus atricauda and Sparisoma cretense from the North-Eastern Atlantic Ocean—Contribution to Risk Assessment

The objective of this study was to study whether the metal concentrations in Sparisoma cretense and Serranus atricauda differ between different coastal areas around the island of Tenerife, Canary Islands and to study whether these species are good bioindicators of pollution. Thirty samples of each species were collected from three parts of the coastline around the island, and samples of muscle and liver tissue were taken from the collected specimens. The determination of the metal content (Al, Cd, Pb, Ca, K, Mg, Na, B, Ba, Cr, Cu, Fe, Li, Mn, Mo, Ni, Zn) was performed by inductively coupled plasma optical emission spectrometry (ICP-OES) before conducting a PERMANOVA analysis. The mean metal concentration was significantly higher in the liver tissue than in the muscle tissue of the two species studied. S. atricauda specimens had a larger number of metals with a higher concentration, and the samples from the northern and eastern zones were found to have a higher concentration of elements than those from the southern zone. The northern and eastern zones were found to have a higher concentration of metals and trace elements than the southern zone, which could be explained by the fact that these zones are more polluted due to their higher population density.

Systemic vascular photobiomodulation accelerates the recovery of motor activity in rats following spinal cord injury.

Spinal cord injury (SCI) causes the discontinuity of the spinal canal, leading to functional and sensorial losses in areas below the injury, which are often irreversible. Photobiomodulation (PBM) can enhance the neuromuscular repair process, especially in cases of peripheral nerve injuries. However, there is little knowledge regarding the effects of this therapeutic modality on recovery following a SCI, especially the noninvasive systemic form denominated vascular PBM (VPBM). To analyze the effects of VPBM in the immediate, acute and intermediate phases following a compression-induced SCI on morphological aspects of neuromuscular tissue repair, functional recovery and the protein expression of brain-derived neurotrophic factor (BDNF). Wistar rats were divided into five groups: control, SCI, SCI + VPBM-Im (immediate administration of VPBM), SCI + VPBM-2h (VPBM administered 2 h after injury) and SCI + VPBM-14d (VPBM administered 14 days after injury). VPBM was administered in the region of the caudal vein/artery with low-level laser (AsGaAl, 780 nm, 80 J/cm², 40 mW for 80 s, totaling an energy of 3.2 J over a single point) for 14 consecutive days. During the analysis periods (1, 3, 7, 14, 21, 28 and 35 days after injury), functioning was evaluated using the Basso-Beattie-Bresnahan (BBB) index. At the end of each experimental period, blood samples were collected for the determination of the concentration of circulating BDNF using ELISA. Muscle tissue and nerve tissue samples were also extracted for morphological and histological analyses using H&E staining. SCI + VPBM-Im and SCI + VPBM-2 h led to the recovery of motor function beginning on the 7th day after injury (p < 0.05), an increase in the cross-sectional area (CSA) of the muscle fibers in the second week (p < 0.05) and an increase in muscle fiber diameter beginning on Day 14 (p < 0.05). Early irradiation had a greater effect on the reduction in the size of the cavity, with stabilization of the cavity found on Day 7 (p < 0.05). Considering the circulating BDNF levels, no changes was found during the experimental periods. The present results showed that VPBM was capable of modulating morphological and functional recovery following SCI, especially when administered early. The positive effects on functional recovery were demonstrated by the BBB index; the reestablishment of the structure of the muscle and nerve tissue was demonstrated by the preservation of CSA and diameter of muscle fiber and reduction in the area of the injury (cavity size) respectively. Thus, noninvasive VPBM may be an important component of treatment for spinal cord injuries.

Accumulation lithium in the tissues and organs of goslings concerning of its level in the mixed feed

We studied the possibility of fortification of goslings’ products with lithium and peculiarities of its depositing in the organs and tissues of goslings concerning lithium level in the mixed feed. Experimental studies have been conducted on goose breed Legart. A total of 320 one-day-old goslings were divided on the principle of analogues into four groups and 80 heads each. The goslings of the first control group did not receive the lithium supplement with the feed mix. Experimental groups were fed with the feed mixed that additionally was supplemented with different doses of lithium by the scheme of the experiment. After 70 days of rearing, three birds were randomly selected from each group and their control slaughter. The lithium content in the representative samples of muscle tissue and organs of goslings was determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES). It was established that feeding the growing goslings with mixed feed containing lithium supplements in doses of 0.05, 0.1 and 0.15 mg/kg, contributed to the increase (P &lt; 0.001) of the concentration of this trace element in the muscles of the thigh and drumstick accordingly 789.5, 1589.5 and at 3447.4 %, in the muscles of the breast 1096.8, 2080.6 and at 3948.4 %, liver are 455.4, 824.6 and at 1440.8 % are compared to goslings that did not receive lithium supplements. Significantly high values of lithium accumulation factors in organs and tissues of gosling (3.21–14.44) indicated that this element has a substantial accumulating capacity. The meat of goslings enriched with lithium can be considered as a natural product with bio-corrective action that can be used in human nutrition. These meat products can be particularly useful for people that are living in regions with a low environmental level of lithium.

Non-invasive estimation of muscle fibre size from high-density electromyography.

Because of the biophysical relation between muscle fibre diameter and the propagation velocity of action potentials along the muscle fibres, motor unit conduction velocity could be a non-invasive index of muscle fibre size in humans. However, the relation between motor unit conduction velocity and fibre size has been only assessed indirectly in animal models and in human patients with invasive intramuscular EMG recordings, or it has been mathematically derived from computer simulations. By combining advanced non-invasive techniques to record motor unit activity in vivo, i.e. high-density surface EMG, with the gold standard technique for muscle tissue sampling, i.e. muscle biopsy, here we investigated the relation between the conduction velocity of populations of motor units identified from the biceps brachii muscle, and muscle fibre diameter. We demonstrate the possibility of predicting muscle fibre diameter (R2 =0.66) and cross-sectional area (R2 =0.65) from conduction velocity estimates with low systematic bias (∼2% and ∼4% respectively) and a relatively low margin of individual error (∼8% and ∼16%, respectively). The proposed neuromuscular interface opens new perspectives in the use of high-density EMG as a non-invasive tool to estimate muscle fibre size without the need of surgical biopsy sampling. The non-invasive nature of high-density surface EMG for the assessment of muscle fibre size may be useful in studies monitoring child development, ageing, space and exercise physiology, although the applicability and validity of the proposed methodology need to be more directly assessed in these specific populations by future studies. KEY POINTS: Because of the biophysical relation between muscle fibre size and the propagation velocity of action potentials along the sarcolemma, motor unit conduction velocity could represent a potential non-invasive candidate for estimating muscle fibre size in vivo. This relation has been previously assessed in animal models and humans with invasive techniques, or it has been mathematically derived from simulations. By combining high-density surface EMG with muscle biopsy, here we explored the relation between the conduction velocity of populations of motor units and muscle fibre size in healthy individuals. Our results confirmed that motor unit conduction velocity can be considered as a novel biomarker of fibre size, which can be adopted to predict muscle fibre diameter and cross-sectional area with low systematic bias and margin of individual error. The proposed neuromuscular interface opens new perspectives in the use of high-density EMG as a non-invasive tool to estimate muscle fibre size without the need of surgical biopsy sampling.

Novel Technology for Facial Muscle Stimulation Combined With Synchronized Radiofrequency Induces Structural Changes in Muscle Tissue: Porcine Histology Study.

With age, facial muscles lose the ability to complete contractions properly, resulting in limitation of facial expressions and fat shifting, and leading to skin creases and wrinkling. The aim of this study was to determine the effects of the novel high intensity facial electromagnetic stimulation (HIFES) technology combined with synchronized radiofrequency on delicate facial muscles, using an animal porcine model. Eight (n = 8, 60-80 kg) sows were divided into the active group (n = 6) and the control group (n = 2). The active group underwent four 20-minute treatments with radiofrequency (RF) and HIFES energies. The control group was not treated. Histology samples of muscle tissue were collected by a punch biopsy (6 mm in diameter) from the treatment area of each animal at baseline, 1-month, and 2-month follow-up. The evaluation included staining of the obtained tissue slices with hematoxylin and eosin and Masson's trichrome to determine the changes in muscle mass density, number of myonuclei, and muscle fibers. The active group showed muscle mass density increase (by 19.2%, P < .001), together with elevated numbers of myonuclei (by 21.2%, P < .05) and individual muscle fibers, which increased from 56.8 ± 7.1 to 68.0 ± 8.6 (P < .001). In the control group, no significant changes were seen in any of the studied parameters throughout the study (P > .05). Finally, no adverse events or side effects were observed in the treated animals. The results document favorable changes after the HIFES + RF procedure at the level of the muscle tissue, which may be of great importance in terms of maintenance of facial appearance in human patients.

Pre-sleep Protein Ingestion Increases Mitochondrial Protein Synthesis Rates During Overnight Recovery from Endurance Exercise: A Randomized Controlled Trial

BackgroundCasein protein ingestion prior to sleep has been shown to increase myofibrillar protein synthesis rates during overnight sleep. It remains to be assessed whether pre-sleep protein ingestion can also increase mitochondrial protein synthesis rates. Though it has been suggested that casein protein may be preferred as a pre-sleep protein source, no study has compared the impact of pre-sleep whey versus casein ingestion on overnight muscle protein synthesis rates.ObjectiveWe aimed to assess the impact of casein and whey protein ingestion prior to sleep on mitochondrial and myofibrillar protein synthesis rates during overnight recovery from a bout of endurance-type exercise.MethodsThirty-six healthy young men performed a single bout of endurance-type exercise in the evening (19:45 h). Thirty minutes prior to sleep (23:30 h), participants ingested 45 g of casein protein, 45 g of whey protein, or a non-caloric placebo. Continuous intravenous l-[ring-13C6]-phenylalanine infusions were applied, with blood and muscle tissue samples being collected to assess overnight mitochondrial and myofibrillar protein synthesis rates.ResultsPooled protein ingestion resulted in greater mitochondrial (0.087 ± 0.020 vs 0.067 ± 0.016%·h−1, p = 0.005) and myofibrillar (0.060 ± 0.014 vs 0.047 ± 0.011%·h−1, p = 0.012) protein synthesis rates when compared with placebo. Casein and whey protein ingestion did not differ in their capacity to stimulate mitochondrial (0.082 ± 0.019 vs 0.092 ± 0.020%·h−1, p = 0.690) and myofibrillar (0.056 ± 0.009 vs 0.064 ± 0.018%·h−1, p = 0.440) protein synthesis rates.ConclusionsProtein ingestion prior to sleep increases both mitochondrial and myofibrillar protein synthesis rates during overnight recovery from exercise. The overnight muscle protein synthetic response to whey and casein protein does not differ.Clinical Trial RegistrationNTR7251.

Histopathological and immunohistochemical study to determine the effects of monosodium glutamate on skeletal muscle development in chickens

The aim of this report was to investigate the effects of MSG administration on embryonic skeletal muscle development in chickens, using histological, histopathological, and immunohistochemical methods. A total of 410 fertilized chicken eggs were used and were divided into five groups: negative control, vehicle control, low-dose group (0.12 mg/g egg MSG), medium-dose group (0.6 mg/g egg MSG), and high-dose group (1.2 mg/g egg MSG). At incubation days 15, 18, and 21, eggs from each group were opened and six live embryos were obtained. The embryos were sacrificed by decapitation, and skeletal muscle tissue samples (musculus fibularis longus and musculus sternocoracoideus pectoralis) were obtained. Sections were stained with hematoxylin-eosin. Moreover, caspase-3 reactivity was determined using the immunohistochemical method. As a result, muscle development was delayed in the MSG groups and the number of caspase-3-positive cells was higher (p &lt; 0.05) than in the controls. Histopathological examinations revealed degenerative and necrotic changes in the skeletal muscle. Muscle degeneration (edema, muscle fiber degeneration, Zenker’s necrosis, and mononuclear cell infiltrations) were observed in all groups, except for the control groups. It was concluded that MSG may have adversely affected the development of the skeletal muscle.

Effects of ethanol storage and lipid extraction on stable isotope compositions of twelve pelagic predators

Stable isotope analysis (SIA) has proven to be a powerful tool in reconstructing diets and characterizing trophic relationships for pelagic predators. Ethanol has been a common preservative solution for biopsy samples from remote areas and archived collections. It is still under debate whether the effects of ethanol (ET) would bias the trophic interpretation of the stable isotope values. Further, lipid extraction (LE) is becoming more popular as a general treatment for standardization prior to SIA, particularly for investigating intra and interspecific variation of sympatric species, because lipids have lower δ13C values. In this study, the long-term (up to 448 days) effects of treatment ET and combined treatments ET and LE (ET+LE) on stable carbon and nitrogen isotope values (δ13C and δ15N, respectively) of twelve pelagic predators from the open ocean were evaluated. Results showed that compared with control values, δ15N values displayed a positive change (δ15Nmean offset was 0.71 ± 0.56‰) but δ13C values had variable results (δ13Cmean offset was 0.42 ± 0.64‰) among all species following treatment with ET during the first 28 days and then remained stable throughout the experiment. Compared with treatment LE results, no difference was observed in δ13C, δ15N values, and C/N ratios through time following treatment ET+LE. These results indicated that treatment ET may have species-specific effects on stable isotope values, and the shifts from treatment LE could counter the changes caused by treatment ET. In addition, after 28 days of preservation, the values following treatment ET were similar to those following treatment LE in low C/N species (C/N&amp;lt;3.5), which suggested ethanol may also affect some of lipid contents from muscle tissues. Nevertheless, further research is needed to focus on the mechanisms that control changes in stable isotope composition in tissues stored in ethanol. Given the effects on pelagic predators, muscle tissue samples stored in ethanol from the open ocean or a museum after LE treatment could be used to develop SIA.

Isolation, characterization, and complete genome sequence of vibrio phage KIT04, a novel lytic phage of the subfamily ermolyevavirinae

Vibrio phage KIT04 was isolated from muscle tissue samples collected from a local market in Vietnam. KIT04 is a lytic phage that is specific to Vibrio parahaemolyticus. The one-step growth curve determined the burst size and latent period of 0.01 multiplicity of infection KIT04 in V. parahaemolyticus as approximately 156 plaque-forming units/bacterium and 45 min, respectively. Vibrio phage KIT04 has an approximately 76.4 ± 4.5 nm diameter icosahedral head and a tail length of approximately 159.5 ± 16.6 nm long tail. KIT04 significantly reduced V. parahaemolyticus ATCC 17802 in vitro. Complete genome analysis showed that KIT04 had a 114,933 bp dsDNA genome with 40.24% G + C content and 160 open reading frames (ORFs). However, the phage genome contained 24 tRNAs and no lysogeny-related genes. Moreover, five of the 160 ORFs encoded unique hypothetical proteins, indicating that KIT04 is a novel phage. Genomic comparison indicated that KIT04 is closely related to the Vibrio phages pVp-1 and VPT02. Further, phylogenetic analysis of the major tail proteins and whole genome supported the KIT04 classification into the subfamily Ermolyevavirinae. Our study describes a new candidate phage that could be used as a bioagent for controlling Vibrio pathogens.

Ewe early gestation supplementation with eicosapentaenoic and docosahexaenoic acids affects the liver, muscle, and adipose tissue fatty acid profile and liver mRNA expression in the offspring.

Our objectives were to assess the effects of eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) supplementation to pregnant ewes during the first third of gestation on their offspring's liver, adipose, and muscle tissues fatty acid (FA) profile and liver mRNA expression after a finishing period receiving diets with different FA profiles. Twenty-four post-weaning lambs, blocked by sex and body weight, were used in a 2 × 2 factorial arrangement of treatments. The first factor was dam supplementation (DS) in the first third of gestation with 1.61% of Ca salts of palm fatty acid distillate (PFAD) or Ca salts enriched with EPA-DHA. Ewes were exposed to rams with marking paint harnesses during the breeding. Ewes started DS at the day of mating, considered day 1 of conception. Twenty-eight days after mating, ultrasonography was used to confirm pregnancy, and nonpregnant ewes were removed from the groups. After weaning, the offspring lambs were supplemented (LS, second main factor) with two different FA sources (1.48% of PFAD or 1.48% of EPA-DHA) during the growing and fattening phase. Lambs were fed the LS diet for 56 d and sent to slaughter, where the liver, muscle, and adipose tissue samples were collected for FA analysis. Liver samples were collected for relative mRNA expression for genes associated with FA transport and metabolism. The data were analyzed as a mixed model in SAS (9.4). In the liver, the amount of C20:5 and C22:6 (P < 0.01) increased in lambs with LS-EPA-DHA, while some C18:1 cis FA isomers were greater in the lambs from DS-PFAD. In muscle, amounts of C22:1, C20:5, and C22:5 increased (P < 0.05) in lambs born from DS-EPA-DHA. The adipose tissue amounts of C20:5, C22:5, and C22:6 were greater (P < 0.01) in lambs from LS-EPA-DHA. Interactions (DS × LS; P < 0.05) were observed for DNMT3β, FABP-1, FABP-5, SCD, and SREBP-1; having greater mRNA expression in liver tissue of LS-EPA-DHA, DS-PFAD and LS-PFAD, DS-EPA-DHA lambs compared with the lambs in the other two treatments. Liver ELOVL2 mRNA relative expression (P < 0.03) was greater in the offspring of DS-PFAD. Relative mRNA expression (P < 0.05) of GLUT1, IGF-1, LPL, and PPARγ increased in the liver from LS-EPA-DHA lambs. Dam supplementation during early gestation using with different FA sources changed the lipid FA profile in MT, LT, and SAT during the finishing period depending on the tissue and type of FA source administered during the growing phase.

Supplementation of palmitoleic acid improved piglet growth and reduced body temperature drop upon cold exposure.

Piglet survival is a major challenge in the first few days postpartum and interventions during this period may improve survival and growth. This study investigated the effects of palmitoleic acid (C16:1n-7; PA) supplementation on growth performance, body temperature, fatty acid (FA), and energy metabolism in milk-replacer-fed piglets. Forty-eight piglets were stratified by body weight and randomly assigned to one of four dietary treatments (0%, 1%, 2%, and 3% PA supplementation as a percent of milk replacer) and given the diet through an orogastric tube. They were fed dietary treatments every 2 h for 4 d in the first week postpartum and all were sacrificed at the end of the experiment. The piglets were weighed daily, and half in each dietary treatment group, the same piglets each day, were exposed daily to a lower temperature for 2 h. Plasma samples were collected immediately before sacrifice for analyses of FA and other plasma metabolites. The weight of organs and empty body weight were determined after sacrifice. Liver and semimembranosus muscle tissue samples were collected and analyzed for FA content. Contents of C16:1n-7 and C18:1n-7 in both plasma and liver (P < 0.001), and C16:1n-7 in semimembranosus muscle (P < 0.001) increased linearly as PA supplementation increased. Most plasma FA levels (except C16:1n-7, C16:1n-9, and C22:5n-3) were lower in piglets exposed to lower temperatures than those that were not. Plasma glucose, triglycerides, and lactate dehydrogenase levels increased linearly with PA supplementation (P < 0.001). Piglets' average daily gain, liver glycogen pool, liver weight, and gallbladder weight increased linearly (P < 0.05, P < 0.01, P < 0.05, and P < 0.001, respectively), but lung weight, liver nitrogen content, and body temperature drop decreased linearly (P < 0.01, P < 0.001, and P < 0.05, respectively) with PA supplementation. Piglets exposed to low temperature had greater liver nitrogen (P < 0.05) and lactate dehydrogenase (P < 0.001) contents but had lower liver weight (P < 0.01) and plasma lactate concentration (P < 0.05) than those that were not. In conclusion, this study demonstrated the importance of PA on the growth performance of the piglets by increasing their average daily gain and decreasing a drop in body temperature upon cold exposure, most likely due to a modified energy metabolism.

Establishment of a method for detecting Trichinella spiralis in ovine muscle tissues using real-time fluorescence quantitative PCR

Trichinellosis is caused by Trichinella spiralis, a meat-borne zoonotic disease transmitted to humans through the consumption of infected undercooked or raw meat. Surveillance using safe and precise diagnostic tools to diagnose T. spiralis in sheep is needed to assess the incidence and probability of transmission from sheep to humans. In this study, we developed a real-time PCR assay to detect T. spiralis DNA in ovine muscle samples that can be used as an alternative surveillance tool to ensure food safety using newly designed primers. The assay is specific for the Scfld4 gene of Trichinella (T1) and enables the detection of larvae in ovine muscle tissue samples with high sensitivity and specificity. Trichuris ovis, Oesophagostomum dentatum, Haemonchus contortus, and Bunostomum trigonocephalum showed no nonspecific amplification. The assay could detect Trichinella DNA concentrations as low as 0.0026 ng/μL, equivalent to 0.0064 larvae, indicating a high sensitivity for T. spiralis detection. We used this real-time PCR to detect 73 ovine muscle samples from an ovine abattoir, and five samples tested positive via real-time PCR but negative via microscopy. This assay may provide a more specific and sensitive method for rapidly detecting Trichinella larvae in ovine muscle tissues.

Bioaccumulation of mercury in direct-developing frogs: The aftermath of illegal gold mining in a National Park

The use of mercury in mining gold is an illegal but still common practice in developing countries and is the world’s largest source of mercury pollution. The mercury released into the environment bioaccumulates in organism tissues due to its chemical properties and can adversely alter wildlife's neurological and reproductive systems. Frogs are susceptible to mercury contamination from gold mining because of their high skin permeability and association with aquatic environments. However, the effect of mercury pollution on direct-developing frogs is poorly known, particularly in tropical highlands. To understand the impact of mercury due to gold mining contamination on biodiversity of Tropical Andes, we assessed the bioaccumulation of mercury on direct-developing frogs of genus Pristimantis in a montane forest. We assessed bioaccumulation by comparing muscle tissue samples of frogs and sediments of streams in an area previously affected by illegal gold mining inside the Farallones de Cali National Park. Even though gold mining has not been conducted in the area for several years, we found mercury in muscle samples of direct-developing species of genus Pristimantis and alarming mercury concentrations in the sediment samples that exceed risk thresholds according international guidelines of the WHO (1.0749 μg.g-1) and countries such as Canada, USA and Brazil (0.35 μg.g-1). Our results suggest that the use of heavy metals in the gold mining can affect non-aquatic species causing bioaccumulation of heavy metals, which can be an important threat to wildlife populations, the stability of the ecosystem, and public health. Keywords: Andean forests, mercury pollution, muscle tissue, streams pollution, sediments, total mercury

Comparison of cytokine production in mice inoculated with messenger RNA vaccines BNT162b2 and mRNA-1273.

Two messenger RNA (mRNA) vaccines of BNT162b2 and mRNA-1273 were licensed. The most common adverse event is regional pain at the injection site in 80%. As systemic reactions, fatigue and headache were noted in 40%-60% and febrile illness in 10%-40% of the recipients. To investigate the mechanism of adverse events, cytokine profiles were investigated in mice. Muscle tissue and serum samples were obtained on days 0, 1, 3, 5, and 7, and at 2 and 4 weeks after the first dose. The second dose was given 4 weeks after the first dose and samples were obtained. After inoculation with 0.1 mL of mRNA-1273, IFN-γ and IL-2 were detected in muscle tissues and serum samples on day 1 of the second doses, and similar profiles were observed for IL-4, IL-5, and IL-12 production. mRNA-1273 induced higher levels of Th1 and Th2 cytokines. TNF-α was induced in muscle tissues on day 1 of the first dose and enhanced on day 1 of the second dose after inoculation with BNT162b2 and mRNA-1273. IL-6 was also detected in muscle tissue on day 1 of the first dose, but it decreased after day 3, and enhanced production was demonstrated on day 1 of the second dose. Granulocyte colony-stimulating factor in muscle tissues showed a similar profile. The induction of inflammatory cytokines in the mouse model is related to the cause of adverse events in humans, with a higher incidence of adverse events after the second dose.

Caffeine-Supplemented Diet Prevents Fatigue-Like Behavior in Tumor-Bearing Mice

Caffeine is a widely consumed stimulant, known for its positive effects on physical and mental performance. These effects are potentially beneficial for ameliorating cancer-related fatigue, which affects the quality of life of patients with cancer. This study aimed to determine the anti-fatigue and antitumor effects of caffeine in tumor-bearing mice. BALB/c mice were intravenously injected with C26 colon carcinoma cells and fed with normal or 0.05% caffeine-supplemented diet. Fatigue-like behavior was assessed by running performance using a treadmill test. Lung, blood, liver, muscle, and epididymal adipose tissue samples were collected on day 13 and examined. The antitumor effect of caffeine was assessed using subcutaneous tumor-bearing mice fed with 0.05% caffeine-supplemented diet, and the tumor volume was measured. C26 tumor-bearing mice showed fatigue-like behavior associated with hypoglycemia, depleted liver glycogen and non-esterified fatty acid (NEFA) levels. C26 tumor-bearing mice fed with 0.05% caffeine-supplemented diet showed improved running performance associated with restored NEFA levels. However, exacerbated hypoglycemia and liver glycogen levels after caffeine consumption may be due to tumor-induced catabolic signals, as the tumor volume was not affected. Collectively, caffeine may exert anti-fatigue effects through enhanced lipolysis leading to restored NEFA levels, which can be used as an alternative energy source.

Phosphoproteomic analysis identifies differentially expressed phosphorylation sites that affect muscle fiber type in pigs.

Skeletal muscle of livestock is composed of both fast- and slow-twitch muscle fibers, which are key factors in their meat quality. However, the role of protein phosphorylation in muscle fiber type is not completely understood. Here, a fast-twitch (biceps femoris, BF) and slow-twitch (soleus, SOL) muscle tissue sample was collected from three male offspring of Duroc and Meishan pigs. We demonstrate that the meat quality of SOL muscle is significantly better than that of BF muscle. We further used phosphoproteomic profiling of BF and SOL muscles to identify differences between these muscle types. A total of 2,327 phosphorylation sites from 770 phosphoproteins were identified. Among these sites, 287 differentially expressed phosphorylation sites (DEPSs) were identified between BF and SOL. GO and KEGG enrichment analysis of proteins containing DEPSs showed that these phosphorylated proteins were enriched in the glycolytic process GO term and the AMPK signaling pathway. A protein-protein interaction (PPI) analysis reveals that these phosphorylated proteins interact with each other to regulate the transformation of muscle fiber type. These analyses reveal that protein phosphorylation modifications are involved in porcine skeletal muscle fiber type transformation. This study provides new insights into the molecular mechanisms by which protein phosphorylation regulates muscle fiber type transformation and meat quality in pigs.

Acute Quark Ingestion Increases Muscle Protein Synthesis Rates at Rest with a Further Increase after Exercise in Young and Older Adult Males in a Parallel-Group Intervention Trial

BackgroundIngestion of protein concentrates or isolates increases muscle protein synthesis rates in young and older adults. There is far less information available on the anabolic response following the ingestion of dairy wholefoods, which are commonly consumed in a normal diet. ObjectivesThis study investigates whether ingestion of 30 g protein provided as quark increases muscle protein synthesis rates at rest and whether muscle protein synthesis rates are further increased after resistance exercise in young and older adult males. MethodsIn this parallel-group intervention trial, 14 young (18–35 y) and 15 older (65–85 y) adult males ingested 30 g protein provided as quark after a single-legged bout of resistance exercise on leg press and leg extension machines. Primed, continuous intravenous L-[ring-13C6]-phenylalanine infusions were combined with the collection of blood and muscle tissue samples to assess postabsorptive and 4-h postprandial muscle protein synthesis rates at rest and during recovery from exercise. Data represent means ± SDs; η2 was used to measure the effect size. ResultsPlasma total amino acid and leucine concentrations increased after quark ingestion in both groups (both time: P < 0.001; η2 > 0.8), with no differences between groups (time × group: P = 0.127 and P = 0.172, respectively; η2<0.1). Muscle protein synthesis rates increased following quark ingestion at rest in both young (from 0.030 ± 0.011 to 0.051 ± 0.011 %·h−1) and older adult males (from 0.036 ± 0.011 to 0.062 ± 0.013 %·h−1), with a further increase in the exercised leg (to 0.071 ± 0.023 %·h−1 and to 0.078 ± 0.019 %·h−1, respectively; condition: P < 0.001; η2 = 0.716), with no differences between groups (condition × group: P = 0.747; η2 = 0.011). ConclusionsQuark ingestion increases muscle protein synthesis rates at rest with a further increase following exercise in both young and older adult males. The postprandial muscle protein synthetic response following quark ingestion does not differ between healthy young and older adult males when an ample amount of protein is ingested.This trial was registered at the Dutch Trial register, which is accessible via trialsearch.who.int www.trialregister.nl as NL8403.

Monitoring of Heavy Metals Concentration in European Hake

Fish consumption ensure health benefits, nevertheless the existence of heavy metal pollution in seafood still deputize public health concerns. These study aims to evaluate the concentration levels of cadmium and chrome in muscle tissue of European Hake (Merluccius merluccius) with different size. Fish samples were collected and purchased regularly from the central fresh fish market of Tirana whereas a total of 44 samples of muscle tissue were evaluate by using atomic absorption spectrophotometer (AAS). The results of the investigation showed that, cadmium concentration levels (p=0.001) varied significantly between fish sample size of European Hake. According to the results concentration levels of cadmium made an exception (0.04 mg/kg ww), over passing (large fish size) the maximum permitted level for human consumption set by EC legislation. Based to the results of the investigation it will be of great interest the further evaluation and monitoring of European hake specie with the aim to protect Albanians consumers’ health by cadmium contamination.