Stereological Assessment Research Articles

Dendritic alterations precede age-related dysphagia and nucleus ambiguus motor neuron death.

Motor neurons (MNs) within the nucleus ambiguus innervate the skeletal muscles of the larynx, pharynx and oesophagus, which are essential for swallow. Disordered swallow (dysphagia) is a serious problem in elderly humans, increasing the risk of aspiration, a key contributor to mortality. Despite this importance, very little is known about the pathophysiology of ageing dysphagia and the relative importance of frank muscle weakness compared to timing/activation abnormalities. In elderly humans and in aged Fisher 344 (F344) rats, a variety of motor pools exhibit weakness and atrophy (sarcopenia), contemporaneous to MN death. Synchronisation of swallow is dependent on the stability of MN dendrites, which integrate neural circuits. Dendritic derangement occurs in many neuromotor degenerative conditions prior to MN death. We hypothesise behavioural weakness and death of nucleus ambiguus MNs will occur by age 24months in F344 rats and that this will be preceded by swallow-respiration dyscoordination and dendritic arbour degenerations from 18months compared to controls at 6months. Using pressure catheters to estimate laryngeal and diaphragm function during naturalistic water bolus applications, we show that swallow number and post-swallow apnoeas are altered from 18months. Swallow pressure (weakness) and nucleus ambiguus MN numbers (evaluated via stereological assessments of Nissl staining) were reduced at 24months. Dendritic lengths, surface areas and dendritic spines were reduced in nucleus ambiguus MNs from 18months (evaluated by confocal imaging of Golgi-Cox impregnated brainstem). These results show that synapse loss occurs prior to MN death and behavioural weakness. Strategies to preserve synapses may be of utility in ameliorating sarcopenia. KEY POINTS: Dysphagia is a major contributor to ageing morbidity and mortality, but the underling pathophysiology is unexplored. Here, in Fischer 344 rats, we use pressure and timing evaluations of swallow-respiration, showing timing impairments occur prior to frank pressure defects. In nucleus ambiguus motor neurons, dendritic defects were apparent with the onset of swallow-respiration dyscoordination, with frank motor neuron loss occurring subsequently to synapse loss. Our results show that synapse loss occurs prior to motor neuron death and behavioural impairments. Strategies to preserve synapses may be of utility in ameliorating sarcopaenia.

A Single Early Life Acetaminophen Exposure Causes Persistent Abnormalities in the Murine Lung.

Whether early life acetaminophen (APAP) exposures injure the developing lung is controversial. We sought to correlate murine pulmonary developmental expression profiles of Cyp2e1 to susceptibility to APAP exposure. P14 C57BL/6 mice were exposed to APAP (140 mg/kg x 1, IP) and assessed for evidence of a histologic, metabolic, functional, and/or transcriptional pulmonary response. Similar experiments were performed in P14 IL6-/- mice given the controversial role of IL6 in APAP-induced tissue injury. No evidence of hepatic injury was noted in APAP exposed P14 mice. In contrast, within 6 hours of exposure pulmonary tissue demonstrated histologic and functional evidence of injury and increased mitochondrial load by fluorescent lifetime imaging microscopy (FLIM). The pulmonary transcriptional response was marked by increased expression of Cyp2e1, Nrf2 targets, and pro-inflammatory genes. Specifically, APAP exposure increased pulmonary IL6 mRNA, protein and associated STAT3 signaling. In contrast, IL6-/- demonstrated attenuated STAT3 signaling and injury at 6 hours of exposure. At P28, functional and stereologic assessment of both WT and IL6-/- mice exposed to a single dose of APAP at P14 revealed persistent abnormalities consistent with lung enlargement and alveolar simplification. Developmentally regulated surges in pulmonary Cyp2e1 expression correlate with sensitivity to APAP exposures that do not cause recognizable hepatic injury. A single exposure during this developmental window is enough to cause persistent functional and stereological abnormalities. These results highlight the need to further study the relationship between developmentally-regulated pulmonary Cyp2e1 expression, APAP exposures and long-term pulmonary dysfunction.

A tool to automate assessment of regional brain atrophy in mouse models of neurodegenerative disease.

As life expectancy rises, so too does the prevalence of neurodegenerative diseases. Neurodegeneration causes progressive regional brain atrophy, typically initiating prior to symptom onset. Researchers measure the impact of potential treatments on atrophy in mouse models to assess their effectiveness. This is important because treatments designed to combat neuropathology are more likely to modify the disease, per contra to symptom management. Magnetic resonance imaging, while accurate in measurement of brain region structure volumes, is prohibitively expensive. Conversely, stereological volume assessment, the process of estimating the volume of individual 3D brain regions from imaged 2D brain sections, is more commonly used. This involves manually tracing brain region(s) of interest in regularly spaced imaged cross-sections to determine their 2D area, followed by application of the Cavalieri principle to estimate the volume. The pertinent caveats of this approach are the labor-intensive manual tracing process, and potential inaccuracies that arise due to human variation. To overcome these challenges, we have created a Neuropathology Assessment Tool (NAT) to automate regional brain tracing and identification using artificial intelligence (AI) and concepts from topological data analysis. The NAT was validated by comparing manual and NAT analysis of striatal volume in Huntington disease model mice. The NAT detected striatal atrophy with higher efficiency, 93.8% agreement with manual measurements, and lower inter-group variability. The NAT will increase efficiency of preclinical neuropathology assessment, allowing for a greater number of experimental therapies to be tested and facilitating drug discovery intractable neurodegenerative diseases.

The amelioration effects of ankaferd blood stopper, platelet gel, and Momordica charantia on peripheral nerve injury in the rats: a stereological and ultrastructural study.

Peripheral nerve injuries are commonly encountered in clinical practice. Peripheral nerve injuries most commonly result in serious problems affecting quality of life. The present study is designed to research the possible neuroprotective effects of Ankaferd blood stopper (ABS), platelet-rich plasma (PRP), and Momordica charantia (MC) on regeneration using unbiased stereological techniques. In total, 30 female 8-10week Sprague Dawley rats were randomly divided into five equal groups; control (CG), the group exposed to sciatic nerve resection (Gap) (CGG), additionally following the surgical process ABS, MC, and PRP were injected into collagen tube (ABSG, MCG, PRPG). Nucleator and fractionator methods were used to estimate the number of myelinated and unmyelinated axons, axon area, and myelin sheath thickness. Also, an electron microscopic evaluation was performed. Regarding the number of myelinated axons, significant increases were found in the ABSG, MCG, and PRPG compared with CG (p < 0.05). The protective effects of ABS, PRP, and MC on peripheral nerve regeneration in experimental models in rats were shown using electrophysiological and stereological assessment parameters.

Alpha-synuclein-induced nigrostriatal degeneration and pramipexole treatment disrupt frontostriatal plasticity

Parkinson’s disease is characterized by the degeneration of substantia nigra pars compacta (SNc) dopaminergic neurons, leading to motor and cognitive symptoms. Numerous cellular and molecular adaptations following neurodegeneration or dopamine replacement therapy (DRT) have been described in motor networks but little is known regarding associative basal ganglia loops. This study investigated the contributions of nigrostriatal degeneration and pramipexole (PPX) on neuronal activity in the orbitofrontal cortex (OFC), frontostriatal plasticity, and markers of synaptic plasticity. Bilateral nigrostriatal degeneration was induced by viral-mediated expression of human mutated alpha-synuclein in the SNc. Juxtacellular recordings were performed in anesthetized rats to evaluate neuronal activity in the OFC. Recordings in the dorsomedial striatum (DMS) were performed, and spike probability in response to OFC stimulation was measured before and after high-frequency stimulation (HFS). Post-mortem analysis included stereological assessment of nigral neurodegeneration, BDNF and TrkB protein levels. Nigrostriatal neurodegeneration led to altered firing patterns of OFC neurons that were restored by PPX. HFS of the OFC led to an increased spike probability in the DMS, while dopaminergic loss had the opposite effect. PPX led to a decreased spike probability following HFS in control rats and failed to counteract the effect of dopaminergic neurodegeneration. These alterations were associated with decreased levels of BDNF and TrkB in the DMS. This study demonstrates that nigral dopaminergic loss and PPX both contribute to alter frontostriatal transmission, precluding adequate information processing in associative basal ganglia loops as a gateway for the development of non-motor symptoms or non-motor side effects of DRT.

Attenuation of brown adipocyte whitening in high-fat diet-induced obese rats: Effects of melatonin and β-hydroxybutyrate on Cidea, Fsp27 and MT1 expression.

To investigate the effects of β-hydroxybutyrate (BHB) and melatonin on brown adipose tissue (BAT) plasticity in rats fed a high-fat diet (HFD). We employed a 7-week experimental design for a study on 30 male Sprague-Dawley rats divided into five groups: (1) a control-diet fed group; (2) a high-fat diet (HFD)-fed group; (3) a group that received an HFD and a BHB solution in their drinking water; (4) a group that received an HFD with 10 mg/kg/day melatonin in their drinking water; and (5) a group that received an HFD and were also treated with the combination of BHB and melatonin. Following the treatment period, biochemical indices, gene expression levels of key thermogenic markers (including uncoupling protein 1 [UCP1], PR domain containing 16 [PRDM16], Cidea, fat-specific protein 27 [Fsp27], and metallothionein 1 [MT1]), and stereological assessments of BAT were evaluated. Treatment with BHB and melatonin significantly boosted blood ketone levels, improved lipid profiles, and reduced weight gain from an HFD. It also downregulated genes linked to WAT, namely, Cidea and Fsp27, and upregulated key BAT markers, including UCP1, PRDM16 and peroxisome proliferator-activated receptor-gamma coactivator-1-alpha. Additionally, the co-treatment increased MT1 receptor expression and enhanced the structural density of BAT. The combined oral administration of BHB and melatonin successfully prevented the whitening of BAT in obese rats fed an HFD, indicating its potential as a therapeutic strategy for obesity-related BAT dysfunction. The synergistic effects of this treatment underscore the potential of a combined approach to address BAT dysfunction in obesity.

Transplantation of bioengineered dermal derived matrix-scaffold in combination with hyperbaric oxygen therapy improves wound healing in diabetic rats

Successful treatment of diabetic wounds requires multifactorial approaches. Herein we investigated the effects of a bioengineered three-dimensional dermal derived matrix-scaffold (DMS) in combination with hyperbaric oxygen (HBO) in repairing of wound model in diabetic rats. Thirty days after induction of diabetes, a circular wound was created and treatments were performed for 21 days. Animals were randomly allocated into the untreated group, DMS group, HBO group, and DMS+HBO group. On days 7, 14, and 21, tissue samples were obtained for stereological, molecular, and tensiometrical assessments. Our results showed that the wound closure rate, volume of new dermis and epidermis, numerical density fibroblasts and blood vessels, collagen density, and biomechanical characterize were significantly higher in the treatment groups than in the untreated group, and these changes were more obvious in the DMS+HBO ones. Moreover, the expression of TGF-β, bFGF, miRNA-21, miRNA-146a, and VEGF genes were meaningfully upregulated in treatment groups compared to the untreated group and were greater in the DMS+HBO group. This is while expression of TNF-α and IL-1β, as well as the numerical density of neutrophil and macrophage decreased more considerably in the DMS+HBO group than in the other groups. Overall, using both DMS engraftment and HBO treatment has more effects on diabetic wound healing.

Protective effect of platelet-rich plasma against structural and functional changes of the adult rat testis in carbimazole-induced hypothyroidism.

Hypothyroidism (HT) influences spermatogenesis and is associated with male infertility. Platelet-rich plasma (PRP), a biological product rich in growth factors, promotes tissue repair. In this study, the likely protective effects of PRP on testicular tissue damage in carbimazole (CBZ)-induced HT were evaluated. Forty male rats were divided into four groups. HT was induced by administering CBZ (1.35 mg/kg orally, for 45 days). Two doses of PRP (40 μL each, locally injected into the testis on days 15 and 30) were also given. After 45 days, blood samples were taken from the heart to measure triiodothyronine (T3), thyroxine (T4), and testosterone levels, and semen analysis was performed. For stereological assessment, the left testis was removed, fixed, embedded, sectioned, and stained with hematoxylin and eosin. The right testis was excised to evaluate antioxidant levels. CBZ was demonstrated to induce HT, characterized by significant reductions in T3 and T4. HT was associated with decreased testicular weight, impaired sperm parameters, reduced testosterone concentration, diminished antioxidant activity, reduced volumes of testicular components, and lower total numbers of testicular cells of various types. When HT samples were treated with PRP, improvement was observed for all of these changes. This protective effect could be attributed to the growth factors present in PRP. PRP appears to prevent the structural changes in the testes and the deterioration in sperm quality caused by CBZ-induced HT. This protective effect is likely due to mitigation of oxidative damage and elevation of testosterone levels.

Protective effect of co-enzyme Q10 on testicular tissue and sperm parameters in adult male rats treated with Sunset Yellow FCF

Objective: To determine the protective effect of co-enzyme Q10 (CoQ10) on testicular tissue and sperm parameters in male rats treated with Sunset Yellow FCF. Methods: Sixty male Sprague-Dawley rats were randomly divided into 6 groups of the control, CoQ10 (10 mg/kg/day), low dose of Sunset Yellow (2.5 mg/kg), high dose of Sunset Yellow (70 mg/kg), low dose of Sunset Yellow (2.5 mg/kg) plus CoQ10, and high dose of Sunset Yellow (70 mg/kg) plus CoQ10. The drugs were administered via daily oral gavages for 6 weeks. At the end of the experiment, sperm analysis, stereological and histological assessments of the testis were carried out. Results: The normal morphology (by 41.1%) and progressive spermatozoa (by 74.8%), testicle volume (by 33.4%), lumen volume (by 38.3%), interstitial tissue volume (by 44.7%), seminiferous tubule volume (by 40.7%), and number of spermatogonia (by 53.9%) and Leydig cells (by 70.7%) reduced in the rats that received high doses of Sunset Yellow in comparison to the control group. Nonetheless, all these alterations were recovered by CoQ10 treatment in the CoQ10 plus high dose of Sunset Yellow group. Furthermore, low doses of Sunset Yellow did not affect different parameters of the testis and sperm. Conclusions: CoQ10 could, to some extent, prevent structural changes of the testis induced by the high dose of Sunset Yellow.

Histomorphology of Chorionic Villi of Term Placentae of Mothers Exposed to Retroviral and Hepatitis B Viruses

Retroviral and hepatitis B infections can be potential threats to foetomaternal health through inducing distortions of the architecture and structure of the placenta. Improved insights into the effects of these infections on placental morphology would be integral to our understanding of maternal and neonatal health. Aim: To histomorphologically and stereologically investigate selected placental structures in virus-infected (HIV [human immunodeficiency virus] and hepatitis B virus [HBV]) and uninfected women at term. Method: This cross-sectional study involved the screening of 237 placentae collected at term (38 ± 2 weeks) from the maternity delivery units and surgical theatres of the LEKMA and Weija/Gbawe Municipal Hospitals in Accra. Venous blood samples from the umbilical vein and placenta basal plate blood were screened for HIV, HBV, and hepatitis C virus (HCV) using serological test kits (RDT). A total of 34 placentae were selected, comprising 20 cases and 14 controls that were gestational age-matched. Using stereology and a systematic random sampling technique with test point and intersection counting of photomicrographs, the mean volume densities of syncytial knots, syncytial denudations, foetal capillaries, and intervillous spaces of the placentae were estimated on a total of 2720 photomicrographs. Results: On stereological assessment, there was a statistically significant difference in the mean volume densities of syncytial knots (HIV-infected = 0.562 ± 0.115, HBV-infected = 0.516 ± 0.090, control group = 0.171 ± 0.018, p = 0.001), syncytial denudations (HIV-infected = 0.121 ± 0.022, HBV-infected = 0.111 ± 0.016, control group = 0.051 ± 0.00, p = 0.004), and foetal capillaries (HIV-infected = 0.725 ± 0.152, HBV-infected = 0.902 ± 0.078, control group = 0.451 ± 0.064, p = 0.006) among the different groups of placentae (control) at term. A statistically significant decrease in intervillous space (p = 0.022) was recorded in HBV-infected placentae compared to the control (from 15.450 ± 1.075 to 11.32 ± 0.952). Conclusion: Placental viral infections might lead to significant increases in syncytial knots, foetal capillaries, and syncytial denuded areas of the chorionic villi and a significant decrease in intervillous spaces. This finding could signify evidence of advanced gestation, placental malperfusion, hypermaturity of the placenta, and a possible vertical transmission of the viral antigen to the foetus, which may be crucial in understanding perinatal outcomes.

Sertoli cell-conditioned medium can improve blood-testis-barrier function and spermatogenesis in azoospermia mice induced by scrotal hyperthermia: An experimental study.

An increase in the temperature of the testis is associated with damage to the epithelium of seminiferous tubules and disruption of sperm production. The current study aimed to investigate the effect of the Sertoli cell-conditioned medium (SCCM) on the blood-testis-barrier associated genes and spermatogenesis process following scrotal hyperthermia. In this experimental study, 40 adult NMRI mice (8 wk, 25-30 gr) were allocated into 4 groups: I) control, II) DMEM (10 μl Dulbecco's Modified Eagle Medium), III) scrotal hyperthermia, and IV) scrotal hyperthermia+SCCM (10 μl SCCM). Hyperthermia was induced by placing the mice scrotum in water at 43 C for 20 min every other day for 10 days. Mice were treated every other day for 5 wk. Then the animals were euthanized, and the tails of epididymis were removed to analyze sperm parameters, testis were taken for stereological assessment, reactive oxygen spices and glutathione levels, and the expression of Ocln, Gja1, Cdh2, and Itgb1. The results of sperm analysis indicated that SCCM-treated mice significantly increased sperm count and motility and reduced DNA fragmentation. In addition, histological and molecular findings showed that the volume of testicular tissue, the number of germ cells, the glutathione level, and the expression of Ocln, Gja1, Cdh2, and Itgb1 genes were significantly increased in the SCCM-treated mice. Findings suggest that growth factors of SCCM stimulate the proliferation and differentiation of germ cells through paracrine effects and upregulate the blood-testis-barrier-associated genes in mice subjected to scrotal hyperthermia.

Three-dimensional bioengineered dermal derived matrix scaffold in combination with adipose-derived stem cells accelerate diabetic wound healing

Due to the multifactorial nature of diabetic wounds, the most effective treatments require combinatorial approach. Herein we investigated whether engraftment of a bioengineered three-dimensional dermal derived matrix scaffold (DDMS) in combination with adipose-derived stem cells (ADSs), could accelerate diabetic wound healing. Diabetic animals were randomly planned into the control group, DDMS group, ADS group, and DDMS+ADS group. On days 7, 14, and 21, tissue samples were obtained for stereological, molecular, and tensiometrical assessments. We found that the wound contraction rate, the total volumes of new epidermis and dermis, the numerical densities of fibroblasts and blood vessels, collagen density, and tensiometrical parameters were meaningfully greater in the treated groups than in the control group, and these changes were more obvious in the DDMS+ADS ones (p < 0.05). Moreover, the expression of TGF-β, bFGF, and VEGF genes were considerably upregulated in treated groups compared to the control group and were greater in the DDMS+ADS group (p < 0.05). This is while expression of TNF-α and IL-1β, as well as the numerical densities of neutrophils and macrophages decreased more considerably in the DDMS+ADS group than in the other groups (p < 0.05). Overall, it was found that using both DDMS engraftment and ADS transplantation has more impact on diabetic wound healing.

Decellularized human amniotic membrane loaded with epigallocatechin-3-gallate accelerated diabetic wound healing

Diabetic wounds, as one of the most important complications of diabetes, face many challenges in treatment. Herein we investigated whether decellularized human amniotic membrane (dAM) loaded with epigallocatechin-3-gallate (EGCG) could promote healing in diabetic rats. Sixty diabetic rats were randomly planned into the untreated group, dAM group, EGCG group, and dAM + EGCG group. On days 7, 14, and 21, five rats from each group were sampled for stereological, molecular, and tensiometrical assessments. Our finding revealed that the wound closure rate, the total volumes of new epidermis and dermis, the numerical densities of fibroblasts, blood vessels, collagen density as well as tensiometrical parameters of the healed wounds were considerably increased in the treated groups than in the untreated group, and these changes were more obvious in the dAM + EGCG ones. Furthermore, the expression of TGF-β, bFGF, and VEGF genes were significantly upregulated in all treated groups compared to the untreated group and were greater in the dAM + EGCG group. This is while expression of TNF-α and IL-1β, as well as cell numerical densities of neutrophils and macrophages decreased more considerably in the dAM + EGCG group in comparison to the other groups. In conclusion, it was found that using both dAM transplantation and EGCG has more effect on diabetic wound healing.

Promising improvement in infected Wound Healing in Type two Diabetic rats by Combined effects of conditioned medium of human adipose-derived stem cells plus Photobiomodulation

BackgroundWe aimed to examine the accompanying and solo impacts of conditioned medium of human adipose-derived stem cells (h-ASC-COM) and photobiomodulation (PBM) on the maturation stage of an ischemic infected delayed-healing wound model (IIDHWM) of rats with type 2 diabetes (TIIDM).ResultsOutcomes of the wound closure ratio (WCR) results, tensiometrical microbiological, and stereological assessment followed almost identical patterns. While the outcomes of h-ASC-COM + PBM, PBM only, and h-ASC-COM only regimes were significantly better for all evaluated methods than those of group 1(all, p < 0.001), PBM alone and h-ASC-COM + PBM therapy achieved superior results than h-ASC-COM only (ranged from p = 0.05 to p < 0.001). In terms of tensiometrical and stereological examinations, the results of h-ASC-COM + PBM experienced better results than the PBM only (all, p < 0.001).Conclusionsh-ASC-COM + PBM, PBM, and h-ASC-COM cures expressively accelerated the maturation stage in the wound healing process of IIDHWM with MRSA in TIIDM rats by diminishing the inflammatory reaction, and the microbial flora of MRSA; and increasing wound strength, WCR, number of fibroblasts, and new blood vessels. While the h-ASC-COM + PBM and PBM were more suitable than the effect of h-ASC-COM, the results of h-ASC-COM + PBM were superior to PBM only.

Exosomes derived from adipose stem cells in combination with hyaluronic acid promote diabetic wound healing

Diabetic wound is one of the main challenges in dermatology. Although stem cell-based treatment has therapeutic benefits in wound repair, the clinical application is still limited. Herein we investigated whether adipose stem cells -derived exosomes (Exo) loaded on hyaluronic acid (HA) could promote healing in diabetic rats. Sixty diabetic rats were randomly planned into the control group, Exo group, HA group, and HA+Exo group. On days 7, 14, and 21, five rats from each group were sampled for stereological, molecular, and tensiometrical assessments. Our results indicated that the wound closure rate, the total volumes of new epidermis and dermis, the numerical densities of fibroblasts, the length density blood vessels, collagen density as well as tensiometrical parameters of the healed wounds were significantly higher in the treated groups than in the control group, and these changes were more obvious in the HA+Exo ones. Furthermore, the expression of TGF-β and VEGF genes were meaningfully upregulated in all treated groups compared to the control group and were greater in the HA+Exo group. This is while expression of TNF-α and IL-1β, as well as numerical densities of neutrophils decreased more considerably in the HA+Exo group in comparison to the other groups. Generally, it was found that using both HA injection and exosomes has more effect on diabetic wound healing.

The histomorphological and stereological assessment of rat dorsal root ganglion tissues after various types of sciatic nerve injury.

Peripheral nerve injuries lead to significant changes in the dorsal root ganglia, where the cell bodies of the damaged axons are located. The sensory neurons and the surrounding satellite cells rearrange the composition of the intracellular organelles to enhance their plasticity for adaptation to changing conditions and response to injury. Meanwhile, satellite cells acquire phagocytic properties and work with macrophages to eliminate degenerated neurons. These structural and functional changes are not identical in all injury types. Understanding the cellular response, which varies according to the type of injury involved, is essential in determining the optimal method of treatment. In this research, we investigated the numerical and morphological changes in primary sensory neurons and satellite cells in the dorsal root ganglion 30days following chronic compression, crush, and transection injuries using stereology, high-resolution light microscopy, immunohistochemistry, and behavioral analysis techniques. Electron microscopic methods were employed to evaluate fine structural alterations in cells. Stereological evaluations revealed no statistically significant difference in terms of mean sensory neuron numbers (p > 0.05), although a significant decrease was observed in sensory neuron volumes in the transection and crush injury groups (p < 0.05). Active caspase-3 immunopositivity increased in the injury groups compared to the sham group (p < 0.05). While crush injury led to desensitization, chronic compression injury caused thermal hyperalgesia. Macrophage infiltrations were observed in all injury types. Electron microscopic results revealed that the chromatolysis response was triggered in the sensory neuron bodies from the transection injury group. An increase in organelle density was observed in the perikaryon of sensory neurons after crush-type injury. This indicates the presence of a more active regeneration process in crush-type injury than in other types. The effect of chronic compression injury is more devastating than that of crush-type injury, and the edema caused by compression significantly inhibits the regeneration process.

Exosomes derived from human placental mesenchymal stem cells in combination with hyperbaric oxygen synergically alleviates spinal cord ischemia-reperfusion injury

Spinal cord ischemia-reperfusion injury (IR) is a terrible non-traumatic injury that occurs after abdominal aortic occlusion and causes serious damage to neurological function. Several treatment strategies have been suggested for IR, but they were not unable to effectively improve these conditions. Herein we investigated whether exosomes derived from human placental mesenchymal stem cells (hpMSCs-Exos) in combination with hyperbaric oxygen (HBO) could alleviate injury and promote recovery in IR rats. Eighty male Sprague-Dawley rats were randomly allocated into five equal groups. In addition to the control group that only underwent laparotomy, IR animals were planned into four groups as follows: IR group; IR-Exos group; IR-HBO group; and IR-Exos + HBO group. Neurological function evaluated before, 6 h, 12 h, 24 h, and 48 h after injury. After the last neurological evaluation, tissue samples were obtained for stereological, biochemical, and molecular assessments. Our results indicated that the neurological function scores (MDI), the numerical density of neurons, the levels of antioxidative factors (GSH, SOD, and CAT), and anti-inflammatory cytokine (IL-10) were considerably greater in treatment groups than in the IR group, and these changes were more obvious in the IR-Exos + HBO ones. This is while the numerical density of glial cells, the levels of an oxidative factor (MDA) and inflammatory cytokines (IL-1β, TNF-α, and IL-18), as well as the expression of an apoptotic protein (caspase-3) were meaningfully decreased in treatment groups, especially IR-Exos + HBO group, compared to the IR group. Generally, it was found that co-administration of hpMSCs-Exos and HBO has synergistic neuroprotective effects in the rats undergoing IR.

Exosomes derived from human adipose mesenchymal stem cells loaded bioengineered three-dimensional amniotic membrane-scaffold-accelerated diabetic wound healing.

The occurrence of wounds and defects in the healing process is one of the main challenges in diabetic patients. Herein, we investigated whether adipose-derived stem cells (ADSCs)-derived exosomes loaded bioengineered micro-porous three-dimensional amniotic membrane-scaffold (AMS) could promote healing in diabetic rats. Sixty diabetic rats were randomly allocated into the control group, exosome group, AMS group, and AMS + Exo group. On days 7, 14, and 21, five rats from each group were sampled for stereological, immunohistochemical, molecular, and tensiometrical assessments. Our results indicated that the wound closure rate, the total volumes of newly formed epidermis and dermis, the numerical densities of fibroblasts and proliferating cells, the length density blood vessels, collagen density as well as tensiometrical parameters of the healed wounds were considerably greater in the treated groups than in the control group, and these changes were more obvious in the AMS + Exo ones. Furthermore, the expression of TGF-β, bFGF, and VEGF genes was meaningfully upregulated in all treated groups compared to the control group and were greater in the AMS + Exo group. This is while expression of TNF-α and IL-1β, as well as cell numerical densities of neutrophils, M1 macrophages, and mast cells decreased more considerably in the AMS + Exo group in comparison with the other groups. Generally, it was found that using both AMS transplantation and ADSCs-derived exosomes has more effect on diabetic wound healing.

Loss of larger hypoglossal motor neurons in aged Fischer 344 rats

The intrinsic (longitudinal, transversalis and verticalis) and extrinsic (genioglossus, styloglossus, hyoglossus and geniohyoid) tongue muscles are innervated by hypoglossal motor neurons (MNs). Tongue muscle activations occur during many behaviors: maintaining upper airway patency, chewing, swallowing, vocalization, vomiting, coughing, sneezing and grooming/sexual activities. In the tongues of the elderly, reduced oral motor function and strength contribute to increased risk of obstructive sleep apnoea. Tongue muscle atrophy and weakness is also described in rats, yet hypoglossal MN numbers are unknown. In young (6-months, n = 10) and old (24-months, n = 8) female and male Fischer 344 (F344) rats, stereological assessment of hypoglossal MN numbers and surface areas were performed on 16 µm Nissl-stained brainstem cryosections. We observed a robust loss of ∼15 % of hypoglossal MNs and a modest ∼8 % reduction in their surface areas with age. In the larger size tertile of, age-associated loss of hypoglossal MNs approached ∼30 % These findings uncover a potential neurogenic locus of pathology for age-associated tongue dysfunctions.

Stereological assessment of immunohistochemical markers in the auditory nuclei of bottlenose dolphins

Stereological assessment of immunohistochemical markers in the auditory nuclei of bottlenose dolphins