THE MORPHO-FUNCTIONAL PECULIARITIES OF THE SYNSARCOSIS MUSCLES IN RED SQUIRRELS

In terrestrial species, body propulsion is mostly performed via the pelvic limbs. In semiaquatic species, both pairs of limbs are used in swimming and diving, whereas in arboreal species, the pelvic limbs are used to maintain body stability. Thus, in squirrels, the synsarcosis muscles participate in body propulsion during climbing, as they have well-developed muscular bellies. Among these, the pectoral transverse muscle, which originates along the entire sternum and is inserted on the humeral crest, stands out for its width. The cervical parts of the trapezius and rhomboideus muscles are reduced and their thoracic parts more developed. As a result, muscles such as the occipitoscapularis or atlantoscapularis coordinate forelimb protraction and neck displacement. The serratus ventralis muscle is very well developed and clearly divided into cranial (cervical) and caudal (thoracic) parts; it produces a strong adduction of the thoracic limbs when the parts contract, and when they relax, a large abduction of the forelimbs is produced, enlarging the body size during jumping

Assessment of Physicochemical and In Vivo Biological Properties of Polymeric Nanocapsules Based on Chitosan and Poly(N-vinyl pyrrolidone-alt-itaconic anhydride)

Drug delivery is an important field of nanomedicine, and its aim is to deliver specific active substances to a precise site of action in order to produce a desired pharmacological effect. In the present study nanocapsules were obtained by a process of interfacial condensation between chitosan (dissolved in the aqueous phase) and poly(N-vinyl pyrrolidone-alt-itaconic anhydride), a highly reactive copolymer capable of easily opening the anhydride ring under the action of amine groups of chitosan. The formed amide bonds led to the formation of a hydrogel membrane. The morphology of the obtained nanocapsules, their behavior in aqueous solution of physiological pH, and their ability to encapsulate and release a model drug can be modulated by the parameters of the synthesis process, such as the molar ratio between functional groups of polymers and the ratio of the phases in which the polymers are solubilized. Although a priori both polymers are biocompatible, this paper reports the results of a very detailed in vivo study conducted on experimental animals which have received the obtained nanocapsules by three administration routes—intraperitoneal, subcutaneous, and oral. The organs taken from the animals’ kidney, liver, spleen, and lung and analyzed histologically demonstrated the ability of nanocapsules to stimulate the monocytic macrophage system without producing inflammatory changes. Moreover, their in vivo behavior has been shown to depend not only on the route of administration but also on the interaction with the cells of the organs with which they come into contact. The results clearly argue the biocompatibility of nanocapsules and hence the possibility of their safe use in biomedical applications

Research Progress of Titanium-Based Alloys for Medical Devices

Biomaterials are currently a unique class of materials that are essential to improving the standard of human life and extending it. In the assent of the appearance of biomaterials that contain non-toxic elements, in this study, we examine a system of Ti25Mo7Zr15TaxSi (x = 0, 0.5, 0.75, 1 wt.%) for future medical applications. The alloys were developed in a vacuum electric arc furnace and then studied from a structural, mechanical and in vivo assessment (on rabbits) perspective. The effect of the silicon addition was clearly seen in both the structural and the mechanical characteristics, standing out as beta alloys with a dendritic structure and lowering the mechanical properties as a result of the silicon addition. In experimental rabbits, the proliferation of mesenchymal stem cells was observed in the periosteum and peri-implant area, differentiating into osteoblasts and then into osteocytes. Osteoclasts were discovered within the cartilaginous islands that provide structural support to newly formed bone, playing a primary role in bone remodeling. The newly formed spongy tissue adhered to the fibrous capsule that surrounds the alloy, ensuring good osseointegration of metallic implants. The overexpression of Osteopontin, Metalloproteinase-2 (also known as gelatinase A), and Metallopeptidase-9 (also known as gelatinase B) underscores the processes of osteogenesis, bone mineralization, and normal bone remodeling

Cortisol and Oxytocin Could Predict Covert Aggression in Some Psychotic Patients

Background: The covert or indirect type of aggression has a risk of converting in violent acts and, considering that, it is very important to identify it in order to apply effective preventive measures. In cases of psychotic patients, the risk of becoming violent is harder to predict, as even neuter stimuli may be perceived as threat and trigger aggression. Treating all the psychiatric patients as potential aggressive subjects is not the best preventive measure as only a few of them are aggressive and this measure may further enhance the stigma on mentally ill patients. There is a current need for better understanding of covert aggression and to find objective measures, such as biological markers, that could be indicative of potential violent behavior. In this work, we try to investigate the role of cortisol and oxytocin as potential biomarkers of aggression in patients with psychosis. Material and Methods: We analyzed the level of peripheral oxytocin (pg/mL) and cortisol level (ng/mL) in 28 psychotic patients (they were not on psychotropic treatment at the moment of admission and those with substance abuse or personality disorder were excluded from the study) and correlated it with the intensity of aggression reported by the patient (overt and covert type) using the Overt Covert Aggression Inventory and the level of observed aggression of the patient in the past 7 days (rated by the health care provider) using the Modified Overt Aggression Scale. Results: We found that psychotic patients with a higher level of covert aggression had a lower level of cortisol (61.05 ± 8.04 ng/mL vs. 216.33 ± 12.6.9 ng/mL, p ˂ 0.01) and a higher level of oxytocin (102.87 ± 39.26 vs. 70.01 ± 25.07, p = 0.01) when compared with patients with a lower level of covert aggression. Furthermore, we observed significant negative correlation between cortisol and covert aggression (r = −0.676, p < 0.001) and between oxytocin and covert type of aggression (r = 0.382, p = 0.04). Moreover, we found that a lower level of cortisol together with a higher level of oxytocin are significant predictors of a style of internalized manifestation of aggression, with the predictive model explaining 55% of the variant of the internalized manifestation of aggression (F (2.25) = 17.6, p < 0.001, β = 0.35, R2 = 55.2). We did not find significant correlations between cortisol and overt aggression, and neither between oxytocin and overt aggression. Positive correlations were also found between the overt type of self-reported aggression and overt aggression reported by the rater (r = 0.459, p = 0.01). Conclusions: The importance of a predictive model in understanding covert aggression is imperative and the results of our study show that oxytocin and cortisol warrant to be further investigated in establishing a definitive predictive model for covert aggression

Assessment of the Effects of Si Addition to a New TiMoZrTa System

Ti-based alloys are widely used in medical applications. When implant devices are used to reconstruct disordered bone, prevent bone resorption and enhance good bone remodeling, the Young’s modulus of implants should be close to that of the bone. To satisfy this requirement, many titanium alloys with different biocompatible elements (Zr, Ta, Mo, Si etc.) interact well with adjacent bone tissues, promoting an adequate osseointegration. Four new different alloys were obtained and investigated regarding their microstructure, mechanical, chemical and biological behavior (in vitro and in vivo evaluation), as follows: Ti20Mo7Zr15Ta, Ti20Mo7Zr15Ta0.5Si, Ti20Mo7Zr15Ta0.75Si and Ti20Mo7Zr15TaSi. 60 days after implantation, both in control and experimental rabbits, at the level of implantation gap and into the periimplant area were found the mesenchymal stem cells which differentiate into osteoblasts, then osteocytes and osteoclasts which are involved in the new bone synthesis and remodeling, the periimplant fibrous capsule being continued by newly spongy bone tissue, showing a good osseointegration of alloys. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay confirmed the in vitro cytocompatibility of the prepared alloys