Impact of Transphyseal Elastic Nailing On the Histostructure of the Tibia in Growing Animals (Non-Randomized Controlled Experimental Study)

BACKGROUND: The use of intramedullary elastic nailing is a method of choice for prevention of complications in children with osteogenesis imperfecta. However, the morphology of the growing long bones in the conditions created was not investigated. AIM: The purpose of our experiment was to study the impact of elastic intramedullary nailing on the histostructure of long bones in their physiological growth. METHODS: Six mongrel dogs underwent intramedullary elastic transphyseal nailing of the intact tibia with two titanium wires. Six months after nailing, a light-optical microscopic and histomorphometric study of the operated and contralateral tibiae was performed. RESULTS: It was found that asymmetric lesion of the distal physis induces a decrease in the height of the distal epimetaphysis. Adaptive changes in the hyaline cartilage of both articular ends were revealed corresponding to the initial stage of chondropathy. Intramedullary nailing promotes an increase in the thickness of the compact bone and the volume of the trabecular bone. CONCLUSIONS: Elastic transphyseal nailing of the intact tibia has a shaping effect which is expressed by an increase in the volume of spongy and compact bone, adaptive changes in the hyaline cartilage. Asymmetric damage to growth zones should be avoided to prevent deformities

Towards in vivo photomediated delivery of anticancer peptides: Insights from pharmacokinetic and -dynamic data

An in vivo study of a photoswitchable cytotoxic peptide LMB040 has been undertaken on a chemically induced hepatocellular carcinoma model in immunocompetent rats. We analysed the pharmacokinetic profile of the less toxic photoform (“ring-closed” dithienylethene) of the compound in tumors, plasma, and healthy liver. Accordingly, the peptide can reach a tumor concentration sufficiently high to exert a cytotoxic effect upon photoconversion into the more active (“ring-open”) photoform. Tissue morphology, histology, redox state of the liver, and hepatic biochemical parameters in blood serum were analysed upon treatment with (i) the less active photoform, (ii) the in vivo light-activated alternative photoform, and (iii) compared with a reference chemotherapeutic 5-fluorouracil. We found that application of the less toxic form followed by a delayed in vivo photoconversion into the more toxic ring-open form of LMB040 led to a higher overall survival of the animals, and signs of enhanced immune response were observed compared to the untreated animals

Bioactivity and osteointegration of hydroxyapatite-coated stainless steel and titanium wires used for intramedullary osteosynthesis

Abstract A lot of research was conducted on the use of various biomaterials in orthopedic surgery. Our study investigated the effects of nanostructured calcium–phosphate coating on metallic implants introduced into the bone marrow canal. Stainless steel or titanium 2-mm wires (groups 1 and 2, respectively), and hydroxyapatite-coated stainless steel or titanium wires of the same diameter (groups 3 and 4, respectively) were introduced into the tibial bone marrow canal of 20 dogs (each group = 5 dogs). Hydroxyapatite coating was deposited on the wires with the method of microarc oxidation. Light microscopy to study histological diaphyseal transverse sections, scanning electron microscopy to study the bone marrow area around the implant and an X-ray electron probe analyzer to study the content of calcium and phosphorus were used to investigate bioactivity and osteointegration after a four weeks period. Osteointegration was also assessed by measuring wires’ pull-off strength with a sensor dynamometer. Bone formation was observed round the wires in the bone marrow canal in all the groups. Its intensity depended upon the features of wire surfaces and implant materials. Maximum percentage volume of trabecular bone was present in the bone marrow canals of group 4 dogs that corresponded to a mean of 27.1 ± 0.14%, while it was only 6.7% in group 1. The coating in groups 3 and 4 provided better bioactivity and osteointegration. Hydroxyapatite-coated titanium wires showed the highest degree of bone formation around them and greater pull-off strength. Nanostructured hydroxyapatite coating of metallic wires induces an expressed bone formation and provides osteointegration. Hydroxyapatite-coated wires could be used along with external fixation for bone repair enhancement in diaphyseal fractures, management of osteogenesis imperfecta and correction of bone deformities in phosphate diabetes

Influence of A New Derivative of 4-aminobutanoic Acid on the Level of Neuromediatory Aminoacids, Neuromediators and the State of the Rats' Hypocamp in Conditions of Brain Ischemia

The aim: to investigate the effect of a new derivative of 4-aminobutanoic acid (compounds KGM-5) on the level of neurotransmitters and neurotransmitter amino acids and the structural-functional state of the hippocampus of rats with acute cerebrovascular accident (ACVA). Materials and methods. ACVA was reproduced in rats by occlusion of the left carotid artery under anesthesia (sodium thiopental (35 mg/kg) intraperitoneally (i/p). 5 groups of animals were used: intact control (IC, n=6), untreated animals with ACVA (CP, n=13); animals with ACVA (n=14), which were treated for 5 days with KGM-5 at a dose of 30 mg/kg i/p, animals with ACVA (n=13), who received i/p comparison drug “Picamilon” (17 mg/kg). There was a group of pseudo-operated animals (POA, n=8). Withdrawal of animals from the experiment was performed on day 6 after modeling ACVA by painless euthanasia under anesthesia. Histological examinations of CA1 and CA3 zones of the ventral hippocampus were performed with staining of sections with thionine by the method of Nissl and hematoxylin, eosin. In the rat brain, neurotransmitter amino acids and neurotransmitters were identified. Statistical processing was performed using the W-Shapiro-Wills test to verify the normality of the distribution and the nonparametric Mann-Whitney U-test. The accepted significance level is p<0.05. Results. Under the influence of the compound KGM-5 and “Picamilon” in the CA1 zone of the hippocampus, the number of normochromic neurons increased by 20 % and 16.6 %, respectively, hyperchromic pycnomorphic neurons and shadow cells decreased respectively by 5.8; 2.9 times and 6.3; 3.5 times, the index of alteration of neurons decreased by 6 times and 4.8 times, respectively, the area of ​​the perikaryon of these neurons increased by 39.7 % and 77.8 %, respectively, compared with KP (p<0.05). Both studied agents showed a less pronounced normalizing effect on the CA3 area of the hippocampus. The new compound KGM-5 showed a normalizing effect similar to “Picamilon” on the level of neurotransmitter amino acids and neurotransmitters in the brain of rats with ACVA. Conclusions. Therapeutic administration of KGM-5 increases the survival of ventral hippocampal neurons, reducing the relative proportion of irreversibly altered cells, and helps to restore impaired levels of neurotransmitter amino acids and neurotransmitters in the brain of rats with ACVA. The neuroprotective effect of the new compound KGM-5 corresponds to this comparison drug “Picamilon

Infestation of pine (Pinus sylvestris L.) seedlings with the pinewood nematode Bursaphelenchus xylophilus Steiner and Buhrer (Nickle) through wood sawdust

Abstract Key message There are various pathways for infesting pine trees with the pinewood nematode (PWN), Bursaphelenchus xylophilus. As a result of the experiment, we determined that sawdust infested with the nematode can pose a phytosanitary risk. Nematodes actively moved from infested sawdust into root or stem damaged pine seedlings. Context The spread of PWN, Bursaphelenchus xylophilus in pine plantations and forests is caused by beetles of the genus Monochamus, but the nematode can also be introduced via different coniferous commodities. Aims The study objective was to assess the possibility that injured roots and stems of Pinus sylvestris seedlings could be infested with PWN through nematode-infested sawdust. Methods Experiments of PWN infestation of pines were conducted in a climatic chamber at a temperature of 26 °C and moisture content of 60–70%. After a month in the climatic chamber, the seedlings were exposed to PWN through infested sawdust. Results It was determined that PWN actively penetrated seedlings with injured stems when directly exposed to PWN-infested sawdust (83% of seedlings (p < 0.012)). Similar results were obtained in the trial in which during planting, seedlings with damaged roots were exposed to PWN infested sawdust (50% of seedlings (p < 0.008)). The nematodes could not infest seedlings if the sawdust occurred on the soil surface at a distance of 2.5 cm from the seedling stem. Conclusion Our results indicate nematode infestation of pine trees can occur through PWN-infested sawdust

Antiherpetic Activity of Carrageenan Complex with Echinochrome A and Its Liposomal Form

Herpes simplex virus (HSV) infections, the incidence of which is still widespread throughout the world, are actualizing the search and development of new, more effective antiherpetic drugs. The development of multifunctional drug delivery systems, including liposome-based ones, has become a relevant and attractive concept in nanotechnology. The ability of complexes of &kappa;- and &Sigma;-carrageenans (CRGs)&mdash;sulfated polysaccharides of red algae, with echinochrome A (Ech), as well as the liposomal form of the &Sigma;-CRG/Ech complex&mdash;to inhibit different stages of HSV-1 infection in Vero cells was studied. By quantum chemical calculations, it was shown that CRG forms stable complexes with Ech. We have shown that complexes of &kappa;-CRG/Ech and &Sigma;-CRG/Ech exhibit highest virucidal activity with a selectivity index (SI) of 270 and 350, respectively, and inhibition of virus-cell interaction (SI of 83 and 32, respectively). The liposomal form of the &Sigma;-CRG/Ech complex after virus adsorption and penetration to cells effectively reduced the HSV-1 plaque formation. The virus-inhibiting activity of the liposomal form of the &Sigma;-CRG/Ech complex was three times higher than that of the &Sigma;-CRG/Ech complex itself. Obtaining CRGs/Ech complexes and their liposomal forms can become the basis of a successful strategy for the development of promising antiherpetic drugs

Chromium spinel in Late Quaternary volcanic rocks from Kamchatka: Implications for spatial compositional variability of subarc mantle and its oxidation state

Highlights • First comprehensive dataset of spinel inclusions in high-Mg olivine from Kamchatka • Oxidation state of parental magmas of Kamchatka ranging from ΔQFM+0.7 to +3.7 • ΔQFM correlates with Ba/La and La/Nb for back-arc magmas of Kamchatka • Decoupling of Cr# and TiO2 in primitive Cr-Spinel suggests slab melt contribution Abstract The Kamchatka volcanic arc (Russia) is one of well-studied but complex tectonic margins on Earth, with an extensive geologic history stretching as far back as the Late Cretaceous. Unlike many other subduction zones, primitive basalts with Mg# > 65 are abundant in Kamchatka, thereby allowing characterization of the mantle source through compositional analyses of near-liquidus minerals in the rocks. In this paper, we present a comprehensive dataset on the composition of Cr-spinel inclusions in olivine for all main Late Quaternary volcanic zones in Kamchatka, comprising of analyses of 1604 spinel inclusions and their host-olivine from 104 samples representing 30 volcanoes and volcanic fields. The studied rocks are basalts, basaltic andesites and high-Mg andesites, which cover the whole compositional range the Late Quaternary primitive volcanic rocks in Kamchatka. The composition of spinel shows large variability. Spinel inclusions with the lowest Cr# and Fe3+/Fe2+ ratios were found in basalts from Sredinny Range and Northern Kamchatka, whereas the most Cr-rich and oxidized spinel inclusions occur in basalts and high-Mg andesites from the Central Kamchatka Depression. Intermediate Cr-spinel compositions characterize the Eastern Volcanic Belt of Kamchatka. The compositions of olivine-spinel pairs were used to quantify the oxidation state of parental Kamchatka magmas and the degree of partial mantle melting. The redox conditions recorded in spinel compositions range from ΔQFM = +0.7 to +3.7. ΔQFM for samples from the Sredinny Range and Northern Kamchatka correlates with a number of proxies of the involvement of slab-derived components incorporated in the composition of their host-rocks (e.g., La/Nb and Ba/La), which suggests a coupling between the mantle oxidation and metasomatism by slab-derived fluids or melts. These correlations were not observed for frontal Kamchatka volcanoes with the highest estimated ΔQFM, which possibly indicates a buffering of the mantle oxidation state by sulfur. The estimated degrees of partial mantle melting range from 8 to >20% for Kamchatka volcanoes. Spinel from the Central Kamchatka Depression has the highest Cr# and could crystallize from magmas generated from the most depleted sources. In contrast to the Eastern Volcanic Belt, spinel Cr# and the inferred degrees of melting in the Central Kamchatka Depression do not correlate with spinel TiO2 content. The apparent decoupling between the proxies of mantle depletion in the CKD spinel is interpreted to reflect refertilization of the CKD mantle by oxidized Ti-rich slab- or mantle lithosphere-derived melts near the northern edge of the subducting Pacific Plate. This study demonstrates that the composition of Cr-spinel in volcanic rocks in combination with bulk-rock compositions can be a powerful tool to map regional variations of the mantle source depletion, oxidation state, and involvement of various slab derived components in island-arc magmatism