Phosphate-buffered Formalin Fixative Under Controlled Fixation Temperature Yielded Excellently Preserved Histomorphology

Aim: Using mouse liver as experimental model, this study attempts to identify a formalin-based fixative and fixation temperature that jointly provides the best balance of preservation of tissue morphology. Methodology: Liver samples from fifty (50) albino mice aged between of 6 to 8 weeks consisting of both male and female was harvested following cervical dislocation and randomly distributed into control and experimental groups. Control samples were fixed in 10mL of 10% formalin at 25oC, 30oC, 35oC, 40oC, 45oC, 50oC, 55oC and 60oC respectively for 24 hours, while experimental samples were each fixed in equal volume of phosphate-buffered 10% formalin (pH 7.2, 7.4, 7.6 and 7.8) at the same temperature and time duration regimen and processed for general tissue morphology. Nuclear, cytoplasm and cell membrane morphology were assessed as evidence of the combined effectiveness of fixative and fixation temperature. Morphology was scored using a four-point grading scale with 1 being poor and 4 being excellent. Results: Nuclear, cytoplasm and cell membrane morphology were excellently preserved in tissue fixed with phosphate-buffered 10% formalin (pH 7.2) at 45oC. Tissue fixed with 10% formalin at 35oC exhibited excellent nuclear and cell membrane morphology, while excellent preservation of cell membrane morphology were observed in tissues fixed with 10% formalin at 40oC, phosphate-buffered 10% formalin (pH 7.4) at 55oC and 60oC, (pH 7.6) at 50oC and 55oC and (pH 7.8) at 55oC respectively. Furthermore, excellent preservation of nuclear morphology was observed in tissue fixed with phosphate-buffered 10% formalin (pH 7.8) at 60oC. Conclusion: Phosphate-buffered 10% formalin at a temperature of 45oC and pH 7.2 provide an excellent formalin-based fixative and fixation temperature that adequately preserves the microanatomy of tissue for histopathology examination.

Intracardial perfusion of the African turquoise killifish v1

This perfusion protocol is essential for preserving tissue morphology in order to perform good quality immunohistochemical stainings. Here, we show you how we perform our perfusions on the African turquoise killifish. This protocol was already used in the following publications: Aging impairs the essential contributions of non-glial progenitors to neurorepair in the dorsal telencephalon of the Killifish Nothobranchius furzeri - PubMed (nih.gov) Single-cell sequencing of the adult killifish (N. furzeri) brain identifies an atypical progenitor, glial and neuronal heterogeneity | bioRxiv

Antidiabetic Properties and Possible Mechanism of the Traditional Chinese Medicine Yi Qi Yang Yin Recipe in Db/db Mice

Background Yi Qi Yang Yin Recipe (YQYY) is a well-known clinical prescription used in Traditional Chinese Medicine (TCM) that ameliorates type 2 diabetes. The aim of the present study was to comprehensively evaluate the efficacy of YQYY granules and explore their mechanism of action. Methods db/db mice were studied as an animal model of type 2 diabetes. After administered with YQYY for eight weeks, food and water consumption, levels of fasting blood glucose, glycosylated serum protein, and liver and pancreas tissue morphology were investigated. In addition, RT-PCR and Westernblot analysis were used to determine the expression of genes and proteins related to glycogen synthesis and gluconeogenesis pathways in the liver. Results YQYY resulted in significantly reduced food and water consumption, and lower fasting blood glucose and glycated serum protein levels. Furthermore, the proliferation of α-cells in db/db mouse pancreatic tissue decreased and liver tissue morphology was significantly ameliorated. YQYY upregulated the expression of phosphorylated GSK-3β and GS proteins in db/db mouse liver tissue, and promoted the synthesis of liver glycogen. Additionally, AMPK was activated, PEPCK and G6Pase gene expression levels decreased, and consequently, gluconeogenesis in the liver was inhibited. Therefore, YQYY improves diabetic phenotyp, suggesting that YQYY could be a prospective agent for preventing and treatment diabetes .

Effects of Chronic Intermittent Hypoxia and Chronic Sleep Fragmentation on Gut Microbiome, Serum Metabolome, Liver and Adipose Tissue Morphology

Chronic intermittent hypoxia (CIH) and chronic sleep fragmentation (CSF) are two cardinal pathological features of obstructive sleep apnea (OSA). Dietary obesity is a crucial risk intermediator for OSA and metabolic disorders. Gut microbiota affect hepatic and adipose tissue morphology under conditions of CIH or CSF through downstream metabolites. However, the exact relationship is unclear. Herein, chow and high-fat diet (HFD)-fed mice were subjected to CIH or CSF for 10 weeks each and compared to normoxia (NM) or normal sleep (NS) controls. 16S rRNA amplicon sequencing, untargeted liquid chromatography-tandem mass spectrometry, and histological assessment of liver and adipose tissues were used to investigate the correlations between the microbiome, metabolome, and lipid metabolism under CIH or CSF condition. Our results demonstrated that CIH and CSF regulate the abundance of intestinal microbes (such as Akkermansia mucinphila, Clostridium spp., Lactococcus spp., and Bifidobacterium spp.) and functional metabolites, such as tryptophan, free fatty acids, branched amino acids, and bile acids, which influence adipose tissue and hepatic lipid metabolism, and the level of lipid deposition in tissues and peripheral blood. In conclusion, CIH and CSF adversely affect fecal microbiota composition and function, and host metabolism; these findings provide new insight into the independent and synergistic effects of CIH, CSF, and HFD on lipid disorders.

Relationship between Connective Tissue Morphology and Lower-Limb Stiffness in Endurance Runners. A Prospective Study

Background: The lower limb behaves like a spring compressing and decompressing during running, where lower-limb stiffness is one of the most influential factors. This prospective observational study is aimed at examining the relationship between the connective tissue morphology and lower-limb stiffness and investigating whether the barefoot/shod condition influences on such relationship. Methods: 14 male amateur runners (10-km time trial <50′) were included. Data were recorded over one session, where participants ran 2 trials (i.e., barefoot and shod conditions) of 3 minutes at 12 km/h, where running spatiotemporal parameters and vertical (Kvert) and leg stiffness (Kleg) were obtained. Prior to testing trials, thickness and cross-sectional area (CSA) were recorded for Achilles (AT) and patellar tendons (PT) and plantar fascia (PF) with ultrasound. Results: Under barefoot condition, a positive correlation was found between Kleg and AT-thickness and CSA and PF-thickness; and between Kvert and AT-thickness and PF thickness. Under shod condition, a positive correlation was found between Kleg and PT-CSA and PT-thickness, and between Kvert and PT-CSA and PT-thickness. Conclusions: The results reveal a specificity of the relationship between the lower-limb stiffness and the morphology of the connective tissue. Greater tendon shows higher lower-limb stiffness when that tendon is specially demanded by the function.

Investigating the preventive effects of 99Tc-methylenediphosphonate on glucocorticoid-induced osteoporosis rabbit model

Background and Objective: Osteoporosis is a worldwide healthcare challenge. Conventional medications for osteoporosis prevention are not clinically effective or associated with gastrointestinal tract adverse effects. The present study aimed to comparatively investigate the effects of technetium-99 conjugated with methylene diphosphonate (99Tc-MDP) and calcium carbonate and alendronate in prevention and treatment of osteoporosis in glucocorticoid-induced osteoporosis rabbit model through evaluating bone alkaline phosphatase (B-ALP), TRAP-5b levels and histopathological parameters. Method: Forty healthy female New Zealand rabbits were randomly divided into five groups (each n=8), including control group (Control Group), osteoporosis model group (GIO Group), osteoporosis model + 99Tc-MDP group (99Tc-MDP Group), osteoporosis model + alendronate group (Alendronate Group), and osteoporosis model + calcium carbonate group (calcium carbonate Group). Animals in each group were treated with corresponding interventions for 14 weeks. The blood samples were collected at the first and 14th week, and B-ALP and TRAP-5b levels were detected by enzyme-linked immunosorbent assay (ELISA). The rabbits were anesthetized at the 14th week, and pathological cytological observation was performed on both femurs. Results: Age and weights of rabbits in different groups had no statistically significant differences (P>0.05). B-ALP levels in serum of all groups except for Control Group decreased after treatment, but the differences were not statistically significant (P>0.05). TRAP-5b levels in serum of all groups increased after treatment. Specifically, differences in the GIO Group and Calcium carbonate Group were statistically significant (P<0.05), while differences in 99Tc-MDP Group and Alendronate‎ Group were not statistically significant (P<0.05). Pathological sections revealed that Control Group presented normal bone tissue morphology. The bone tissue morphology of the 99Tc-MDP Group and Alendronate Group was similar to Control Group and GIO Group. Moreover, Calcium carbonate Group and GIO Group exhibited similar bone tissue morphology. Conclusions: 99Tc-MDP has preventive effect on the glucocorticoid-induced osteoporotic rabbit model. This osteoporosis preventive effect might be attributed to the capacities of 99Tc-MDP in promoting the osteoblasts generation and inhibiting the generation and reducing the activity of osteoclasts.

Biosynthesized ZnO Nanoparticles Using Albizia lebbeck Extract Induced Biochemical and Morphological Alterations in Wistar Rats

Nano-based particles synthesized via green routes have a particular structure that is useful in biomedical applications as they provide cheap, eco-friendly, and non-toxic nanoparticles. In the present study, we reported the effect of various concentrations of Zinc oxide nanoparticles synthesized using A. lebbeck stem bark extract (ZnO NPsAL) as stabilizing agent on rat biochemical profiles and tissue morphology. Adult Wistar rats weighing 170 ± 5 g were randomly classified into eight groups of five rats each; Group A served as a control fed with normal diet and water. Groups B1, B2, C1, C2, D1, D2, and E were treated with 40 mg/kg and 80 mg/kg of the 0.01, 0.05, and 0.1 M biosynthesized ZnO NPsAL and zinc nitrate daily by the gavage method, respectively. The rats were anesthetized 24 h after the last treatment, blood samples, kidney, heart, and liver tissues were collected for biochemical and histopathological analysis. The rats mean body weight, serum alkaline phosphatase, alanine aminotransferase, creatinine, urea, bilirubin, protein, albumin, globulin, total cholesterol, triacylglycerol, and high-density lipoprotein were significantly altered with an increased concentration of biosynthesized ZnO NPsAL when compared with the control group (p < 0.05; n ≥ 5). Furthermore, histopathological analysis of treated rats’ kidney, heart, and liver tissue revealed vascular congestion, tubular necrosis, inflammation, and cytoplasmic vacuolation. Biosynthesized ZnO NPsAL showed significant alteration in biochemical parameters and tissue morphology in rats with increasing concentrations of the nanoparticles.