Protective roles of cornuside in acute myocardial ischemia and reperfusion injury in rats

Cornuside is a secoiridoid glucoside isolated from the fruit of Cornus officinalis SIEB. et ZUCC. In this study, we investigated the anti-myocardial ischemia and reperfusion (I/R) injury effects of cornuside in vivo and elucidated the potential mechanism. Rat models of myocardial I/R were induced by coronary occlusion followed by reperfusion or by Isoproterenol (ISO), treatment of rats with cornuside (20 and 40 mg/kg, i.v.) protected the animals from myocardial I/R injury as indicated by a decrease in infarct volume, improvement in hemodynamics and reduction of myocardial damage severity. Treatment with cornuside also attenuated polymorphonuclear leukocytes (PMNs) infiltration, decreased myeloperoxidase (MPO) activity in the heart, lowered serum levels of pro-inflammatory factors and reduced phosphorylated IκB-α and nuclear factor kappa B (NF-κB) levels in the heart. Additionally, cornuside was shown to have remarkable antioxidant activity and inhibited ISO-induced myocardial cell necrosis. Thus, cornuside appeared to protect the rat from myocardial I/R injury by acting as an anti-inflammatory agent. These findings suggested that cornuside may be used therapeutically in the setting of myocardial I/R where inflammation and oxidant injury are prominent.     

Claustral neurons projecting to frontal cortex restrict opioid consumption

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Sex differences in the detection of motor unit action potentials identified using high-density surface electromyography

Sex-related disparities in force production of humans have been widely observed. Previous literature has attributed differences in peripheral traits, such as muscle size, to explain these disparities. However, less is known about potential sex-related differences in central neuromuscular traits and many comparable studies, not exploring sex-related differences, exhibit a selection-bias in the recruitment of subjects making the generalization of their findings difficult. Utilizing high-density electromyography arrays and motor unit (MU) decomposition, the aim of the current study is to compare MU yield and discharge properties of the tibialis anterior between male and female humans. Twenty-four subjects (10 females) performed two submaximal (20%) isometric dorsiflexion contractions. On average, males yielded nearly twice the amount of MUs as females. Further, females had significantly higher MU discharge rate, lower MU action potential amplitude, and lower MU action potential frequency content than males despite similar levels of torque and MU discharge variability. These findings suggest differences in central neuromuscular control of force production between sexes; however, it is unclear how lower yield counts affect the accuracy of these results.     

Distribution and variation in enamel structure in the oral teeth of sarcopterygians: Its significance for the evolution of a protoprismatic enamel

The property of tooth enamel to resist alteration during fossilization, is used to analyse the unique arrangements of biological crystallites amongst genera of Paleozoic sarcopterygians, with both polarized light and s.e.m. Previous concepts of crystallite organization in reptiles and mammal‐like reptiles are evaluated. Two of the Devonian sarcopterygians, are shown to exhibit a protoprismatic pattern, identical with that of a stem group therian. The patterns of crystallites, together with the arrangement of incremental lines establish that this tissue is solely an ectodermal product; monotypic enamel, in contrast to bitypic enamel with two cell products contributing to it as in enameloid or acrodin. Each genus examined has a different pattern, of significance in considering relationships amongst sarcopterygians. Recent information on ganoine and some new findings on enamel in extant lungfishes have led to the conclusion that types of monotypic enamel are present in both actinopterygians and sarcopterygians, and challenges the use of monotypic enamel as a synapomorphy of sarcopterygians in cladistic analyses.     

Superficial,suprahyoid, and infrahyoid neck musculature in naked mole-rats (Heterocephalus glaber): Relative size and potential contributions to independent movement of the lower incisors

Naked mole-rats (Heterocephalus glaber) are fossorial, eusocial rodents that exhibit the unusual capability of moving their lower incisors independently in lateral and rostroventral directions. The evolution of this trait would presumably also involve concurrent alterations in neck musculature to support and control movements of the lower incisors. In order to assess morphological adaptations that might facilitate these movements, we performed detailed dissections of the neck musculature of adult naked mole-rats. In addition to characterizing attachment sites of superficial, suprahyoid, and infrahyoid musculature, we also quantified muscle mass and mandibular features thought to be associated with gape (condyle height, condyle length, and jaw length). Based on muscle attachment sites, the platysma myoides may contribute to lateral movement of the lower incisor and hemi-mandible in naked mole-rats. The large digastric muscle is likely to be a main contributor to rostroventral movement of each lower incisor. The geniohyoid and mylohyoid muscles also likely contribute to rostroventral movements of the lower incisors, and the mylohyoid may also produce lateral spreading of the hemi-mandibles. The transverse mandibular (intermandibularis) muscle likely serves to reposition the lower incisors back to a midline orientation following a movement.     

Influence of claustrum on cortex varies by area,layer, and cell type

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Escape of the cercarial body of Gorgoderina vitelliloba from its anterior tail chamber

Mitchell J. B. and Mason A. R. 1978. Escape of the cercarial body of Gorgoderina vitelliloba from its anterior tail chamber. International Journal for Parasitology8: 193–198. Before the cercarial body of Gorgoderina vitelliloba can encyst in the body of its second intermediate host it must escape from the anterior tail chamber where it has been confined throughout the free living cercarial phase. Escape from the tail chamber is influenced by pH, enzymes, bile salts and by the physical nature of its environment. The cercarial body effects its escape after first becoming activated and then breaking its connection with the tail.