158 research outputs found

    Effects of Dual Coating Proteins in Intraosseous Transcutaneous Amputation Prosthesis (ITAP)

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    Intraosseous transcutaneous amputation prostheses (ITAP) provide an alternative method of attaching artificial limbs for amputees. Conventional stump-socket devices are associated with soft tissue complications including pressure sores, neuroma formation and tissue necrosis. ITAP overcomes these problems by attaching the articial limb transcutaneously to the skeleton. In order for ITAP to be successful, it requires an infection-resistant transcutaneous barrier at the skin-implant interface. Fibronectin (Fn) and Laminin 332 (Ln), are glycoproteins found abundantly in the extracellular matrix. Dual coating proteins 125 I-Fn + Ln and 125 I-Ln +Fn were covalently bonded to Ti6Al4V through silanization. The hypothesis tested was: silanized dual coating protein coatings with fibronectin and laminin, enhances both keratinocyte and fibroblast spreading and increases vinculin focal adhesion plaques on Ti6Al4V in vitro. Both remained stable when immersed in foetal calf serum compared with adsorbed dual coating proteins at all time points up to 72 hours (p<0.05). There was non-competitive binding of laminin on Ti6Al4V in the presence of fibronectin. Keratinocytes and fibroblasts were grown on Ti6Al4V surfaces with single coating Fn, Ln, and dual coating FnLn on adsorbed, silanized with passivation and silanized without passivation discs. Vinculin focal adhesion markers and cell size were quantified. Silanized dual coating proteins without passivation (SiFnLn-) produced the largest number of vinculin markers and biggest cell size at all time points upt to 24 hours (p<0.05). Hydroxyapatite (HA) is a naturally occurring osteoinductive mineral in the body. 125 I-Fn coated on HA discs was assessed for optimal time for loading, concentration and durability. Fibroblasts were grown on polished, HA and Fn coated HA discs. Vinculin markers and cell size were quantified. Fn coated HA discs increased fibroblast attachment compared to uncoated controls of Ti6Al4V discs and HA discs (p<0.05). My thesis demonstrated silanized without passivation dual coating proteins FnLn produced more viculin markers per cell unit and per cell area when compared to uncoated controls and single coating proteins on adsorbed and silanized, passivated discs. Further research is required to establish whether dual coating proteins will produce the same effect in vivo. This can be achieved by silanizing ITAP with dual coating FnLn and implanting them in animals. Histopathological analysis at the skin-implant interface would provide valuable information whether this biochemical and physical modification improve soft tissue integration to percutaneous implants

    8-[(1E)-1-(2-Aminophenyl­iminio)eth­yl]-2-oxo-2H-chromen-7-olate

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    The title Schiff base, C17H14N2O3, exists as an NH tautomer with the H atom of the phenol group transferred to the imine N atom. The iminium H atom is involved in a strong intra­molecular N+—H⋯O− hydrogen bond to the phenolate O atom, forming an S(6) motif. In the crystal structure, N—H⋯O hydrogen bonds form a C(9) chain parallel to [100] and a C(11) chain parallel to [010], while C—H⋯O hydrogen bonds form a C(11) chain parallel to [010]. The combination of N—H⋯O and C—H⋯O hydrogen bonds generates R 4 3(30) rings parallel to the ab plan

    Configuration of the circle of Willis and its two parts among Egyptian: a magnetic resonance angiographic study

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    Background: We hypothesized that the collateral circulation differs in different ethnic groups. So, the aim of our work was to study variations of the circle of Willis (COW) among Egyptian and to compare our findings with the findings of other nationalities. Materials and methods: One hundred patients were studied using magnetic resonance angiography (3D-TOF-MRA). Frequency and morphologic variations in COW were studied. The diameters of the arteries of the anterior and posterior circle were verified. Finally, the differences among the mean diameters of these arteries regarding age and sex were also studied. Results: Complete, partially complete and incomplete COW were encountered in 28%, 38% and 34% in the studied cases. The incomplete anterior circle was found in 34% (10% isolated incomplete anterior circle and 24% combined incomplete anterior and posterior circles) and the incomplete posterior circle came across in 62% (38% isolated incomplete posterior circle and 24% combined incomplete anterior and posterior circles). Seven anterior circle variations were found. The commonest type was the classical type “a” with a prevalence of 56%, being higher in male (57.1%). The 2nd common type was type “g” (hypoplasia or aplasia of the anterior communicating artery) with a prevalence of 24%, being higher in male (66.7%). Six posterior circle variations were found. The commonest variation was the classic type “a” with a prevalence of 26%, being higher in male (61.5%). Posterior circles types “d, e, h” (18%, 24%, 20%) constituted 62% and were characterised by hypoplasia/absent of the posterior communicating arteries. Conclusions: The prevalence of complete COW (classic or textbook type) was encountered only 28% of the studied cases. Variations of COW were found to be more common in the posterior circulation (62%). The incomplete anterior circle was found in 34% and it is mostly caused by hypoplasia or aplasia of the anterior communicating artery which was found to be more common compared to the literature

    Decrease in local volumetric bone mineral density (vBMD) in osteoarthritic joints is associated with the increase in cartilage damage: a pQCT study

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    Osteoarthritis (OA) is one of the most prevalent joint diseases, which causes pain and disability in the adult population. OA affects the osteochondral unit in the joints, which comprises both cartilage and subchondral bone. There has been some progress in understanding the changes in subchondral bone with progression of OA. However, local changes in subchondral bone such as microstructure or volumetric bone mineral density (vBMD) in connection with the defect in cartilage are relatively unexplored. To develop an effective treatment for progression of OA, it is important to understand how the physical environment provided by the subchondral bone affects the overlying cartilage. In this study, we examined the vBMD distribution in the OA joint tissues obtained from total hip replacement surgeries due to OA, using peripheral quantitative CT (pQCT). It was found that there is a significant decrease in vBMD, which co-localizes with the damage in the overlying cartilage. This was not limited to the subchondral bone immediately adjacent to the cartilage defect but continued in the layers below. Bone resorption and cyst formation in the OA tissues were also detected. We observed that the bone surrounding subchondral bone cysts exhibited much higher vBMD than that of the surrounding bones. pQCT was able to detect significant changes in vBMD between OA and non-OA samples, as well as between areas of different cartilage degeneration, which points to its potential as a technique for detection of early OA

    Stimuli-responsive hydrogels: smart state of-the-art platforms for cardiac tissue engineering

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    Biomedicine and tissue regeneration have made significant advancements recently, positively affecting the whole healthcare spectrum. This opened the way for them to develop their applications for revitalizing damaged tissues. Thus, their functionality will be restored. Cardiac tissue engineering (CTE) using curative procedures that combine biomolecules, biomimetic scaffolds, and cells plays a critical part in this path. Stimuli-responsive hydrogels (SRHs) are excellent three-dimensional (3D) biomaterials for tissue engineering (TE) and various biomedical applications. They can mimic the intrinsic tissues’ physicochemical, mechanical, and biological characteristics in a variety of ways. They also provide for 3D setup, adequate aqueous conditions, and the mechanical consistency required for cell development. Furthermore, they function as competent delivery platforms for various biomolecules. Many natural and synthetic polymers were used to fabricate these intelligent platforms with innovative enhanced features and specialized capabilities that are appropriate for CTE applications. In the present review, different strategies employed for CTE were outlined. The light was shed on the limitations of the use of conventional hydrogels in CTE. Moreover, diverse types of SRHs, their characteristics, assembly and exploitation for CTE were discussed. To summarize, recent development in the construction of SRHs increases their potential to operate as intelligent, sophisticated systems in the reconstruction of degenerated cardiac tissues

    IL-10 correlates with the expression of carboxypeptidase B2 and lymphovascular invasion in inflammatory breast cancer: The potential role of tumor infiltrated macrophages

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    Pro-carboxypeptidase B2 (pro-CPB2) or thrombin-activatable fibrinolysis inhibitor (TAFI) is a glycoprotein encoded by the CPB2 gene and deregulated in several cancer types, including breast cancer. Thrombin binding to thrombomodulin (TM), encoded by THBD, is important for TAFI activation. CPB2 gene expression is influenced by genetic polymorphism and cytokines such as interleukin 10 (IL-10). Our previous results showed that tumor infiltrating monocytes/macrophages (CD14+/CD16+) isolated from inflammatory breast cancer (IBC) patients’ secrete high levels of IL-10. The aim of the present study is to test genetic polymorphism and expression of CPB2 in healthy breast tissues and carcinoma tissues of non-IBC and IBC patients. Furthermore, to investigate whether IL-10 modulates the expression of CPB2 and THBD in vivo and in-vitro. We tested CPB2 Thr325Ile polymorphism using restriction fragment length polymorphism, (RFLP) technique in healthy and carcinoma breast tissues. The mRNA expression of CPB2, THBD and IL10 were assessed by RT-qPCR. Infiltration of CD14+ cells was assessed by immunohistochemistry. In addition, we investigated the correlation between infiltration of CD14+ cells and expression of IL10 and CPB2. Furthermore, we correlated IL10 expression with the expression of both CPB2 and THBD in breast carcinoma tissues. Finally, we validated the role of recombinant IL-10 in regulating the expression of CPB2 and THBD using different breast cancer cell lines. Our results showed that CPB2 genotypes carrying the high-risk allele [Thr/Ile (CT) and Ile/Ile (TT)] were more frequent in both IBC and non-IBC patients compared to control group. CPB2 genotypes did not show any statistical correlation with CPB2 mRNA expression levels or patients’ clinical pathological properties. Interestingly, CPB2 and IL10 expression were significantly higher and positively correlated with the incidence of CD14+ cells in carcinoma tissues of IBC as compared to non-IBC. On the other hand, THBD expression was significantly lower in IBC carcinoma versus non-IBC tissues. Based on molecular subtypes, CPB2 and IL10 expression were significantly higher in triple negative (TN) as compared to hormonal positive (HP) carcinoma tissues of IBC. Moreover, CPB2 expression was positively correlated with presence of lymphovascular invasion and the expression of IL10 in carcinoma tissues of IBC patients. Furthermore, recombinant human IL-10 stimulated CPB2 expression in SUM-149 (IBC cell line) but not in MDA-MB-231 (non-IBC cell line), while there was no significant effect THBD expression. In conclusion, carcinoma tissues of IBC patients are characterized by higher expression of CPB2 and lower expression of THBD. Moreover, CPB2 positively correlates with IL10 mRNA expression, incidence of CD14+ cells and lymphovascular invasion in IBC patients. IL-10 stimulated CPB2 expression in TN-IBC cell line suggests a relevant role of CPB2 in the aggressive phenotype of IBC

    The atmospheres of massiveness: The politics and times of the maybe in Southern megaregions

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    In this introduction to the special issue on massive urbanisation, the collective that has prepared this issue reviews the thinking and experiences that have been important to them. The reflections centre on the use of ‘massive’ in Jamaican patois, where it has two countervailing meanings. On the one hand, it means an inordinate lack of sensitivity to the real conditions taking place, a sense of extreme self-inflation beyond reason. On the other, it means a collectivity coming into being without a set form, but reflective of a desire for collaboration and mutuality. Massive urbanisation thus means here both the voluminous expansion of speculative accumulation, extraction of land value, replication of vast inequities and disfunction, and the continuous emergence of new forms of urban inhabitation, a constant remaking of the social field by what has been called the urban majority. All of the contributions attempt to work with this sense of doubleness, amplifying the creation of particular atmospheres of the urban as a materiality of its heterogeneity
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