Osteoclastic giant cell variant of urothelial carcinoma in a COVID- positive patient: A rare variant in an unusual circumstances

Bladder carcinomas have a great propensity for divergent differentiation with more that 90% being Transitional cell carcinoma. Several histological variants have been have described so far; they are not only morphologically unique but also have significant prognostic and therapeutic differences making their timely identification of paramount importance. Osteoclastic giant cell variant of urothelial carcinoma is very rare type with controversial management. Studies from China have documented higher incidence and severity of illness in COVID-19 positive cancer patients. We report an unusual case of Osteoclastic giant cell variant of urothelial carcinoma in a 63 yrs old male patient associated with simultaneous COVID-19 infection.

Biafra: the Revival and Proliferation of Separatism

The weak cohesion of African societies, predetermined by their ethnic, linguistic and religious heterogeneity, leads to a great propensity for the spread of separatist sentiments in Africa. The overwhelming majority of existing scholarly works note the continent's tendency towards separatism and irredentism. Indeed, the number of separatist movements in Africa is constantly growing; currently there are more of them than there were in the first postcolonial decades, although only a few of them have been “successful”. The present paper analyzes the reasons for the revival of a secessionist movement in southeastern Nigeria several decades after the end of the 1967-1970 Biafran War. The authors consider activities of separatist organizations that emerged in Biafra in the 2000s-2010s, the reaction of the government of Muhammadu Buhari, and factors hindering the establishment of a new “sovereign state” in the region. The relevance of the present paper is determined both by the growing threat of separatism in Africa and by the lack of research on the current situation in Biafra in Russian-language literature. The authors employ theoretical-analytical and systemic-historical methods to analyze the threat of separatism in Nigeria and conclude that the creation of a new “Republic of Biafra” will remain a utopian project for at least the next decade, yet separatist sentiments will spread and hinder the achievement of internal political stability in the country, which is already experiencing conflicts due to the activities of Boko Haram, tensions between farmers and pastoralists, and militancy in the Niger Delta.

Epidemiological and Morphological Characteristics of Urothelial Bladder Cancer in a Bulgarian and a French Sample of Patients

Bladder carcinoma (BC) is one of the most common malignancies of the urinary system in developed countries, and it is also characterized by a high number of recurrences and progression rates despite multimodal treatment. BC is a biological and clinically heterogeneous tumor with a great propensity of divergent differentiation. Around the world, bladder cancer is responsible for 549.000 new cases и 200.000 deaths each year. In Bulgaria, bladder carcinoma is the 18th most common neoplasia. Our results on 105 proven bladder carcinoma cases confirmed that this tumor arises at 70 years at average (60-90 years), it affects men predominantly and there was no difference regarding the nationality of patients. In conclusion, it remains a diagnostic challenge.

Investigation of ash deposit formation on heat transfer surfaces of boilers using coals and biomass

Combustion of coals and biomass in boiler furnaces leads to formation of fireside deposits on irradiated and convective surfaces. This problem is not a new one, but it became one of the main operational problems in boilers using low rank coal and some sort of biomass. In the paper presented are the results of research of ash deposit processes in laboratory conditions. An experimental furnace was used for these purposes. The experiments were performed on a tubular experimental furnace which ensures appropriate temperature and mass transfer conditions for physical and chemical transformations of the mineral matter of fuel as in real conditions. The main working parameters can be varied in wide ranges. The influence of grinding fineness, excess air and wall surface temperature was analysed. Also, an ash related problems during coal and biomass combustion was considered. Key empirical correlations for slagging and fouling were tested. Two types of Serbian coals (Kolubara and Kosovo) and several biomasses were analysed. It was shown that many sorts of biomass and Kosovo coal have a great propensity to slagging and fouling.

Investigation of Combined Cyclodextrin and Hydrogel Formulation for Ocular Delivery of Dexamethasone Acetate by Means of Experimental Designs

Dexamethasone acetate (DXMa) has proven its efficiency to treat corneal inflammation, without a great propensity to increase intraocular pressure. Unfortunately, its poor aqueous solubility, associated with a rapid precorneal elimination, results in a low drug bioavailability and a low penetration after topical ocular administration. The main objective of this study was to improve the apparent aqueous solubility of DXMa using cyclodextrins. First, hydroxypropyl-β-CD (HPβCD) and hydroxypropyl-γ-CD (HPγCD) were used to enhance DXMa concentration in aqueous solution. The β and γ HPCD derivatives allowed the increase of the DXMa amount in solution at 25 °C by a factor of 500 and 1500, respectively. Second, with the aim of improving the persistence of the complex solution after instillation in the eye, the formulations of DXMa-based CD solutions with marketed ophthalmic gels (CELLUVISC®, GEL-LARMES®, and VISMED®) were investigated and optimized by means of special cubic mixture designs, allowing the defining of mixed gels loaded with 0.7% (HPβCD) and 2% (HPγCD) DXMa with osmolality within acceptable physiological range. Finally, in vitro drug release assays from the mixed gels were performed and compared with reference eye drops. Similarly to MAXIDEX® and DEXAFREE®, in the case of mixed gel containing HPβCD, more than 90% of the drug was released within 2 h, while in mixed gel containing HPγCD, the release of DXMa was partial, reaching ≈60% in 2 h. This difference will have to be further addressed with ex vivo and in vivo ocular delivery experiments.

Projectivism

‘Projectivism’ is used of philosophies that agree with Hume that ‘the mind has a great propensity to spread itself on the world’, that what is in fact an aspect of our own experience or of our own mental organization is treated as a feature of the objective order of things. Such philosophies distinguish between nature as it really is, and nature as we experience it as being. The way we experience it as being is thought of as partly a reflection or projection of our own natures. The projectivist might take as a motto the saying that beauty lies in the eye of the beholder, and seeks to develop the idea and explore its implications. The theme is a constant in the arguments of the Greek sceptics, and becomes almost orthodox in the modern era. In Hume it is not only beauty that lies in the eye (or mind) of the beholder, but also virtue, and causation. In Kant the entire spatio-temporal order is not read from nature, but read into it as a reflection of the organization of our minds. In the twentieth century it has been especially non-cognitive and expressivist theories of ethics that have adopted the metaphor, it being fairly easy to see how we might externalize or project various sentiments and attitudes onto their objects. But causation, probability, necessity, the stances we take towards each other as persons, even the temporal order of events and the simplicity of scientific theory have also been candidates for projective treatment.

On the interaction of azithromycin monohydrate with metallic containers

The monohydrate form of azithromycin (an antibiotic semisynthetic derivative of erythromycin A) is difficult to manipulate due to its great propensity to stick to metallic surfaces (during crystallization, drying, grinding,etc.). In this paper, this behaviour is explained on the basis of the conformation and packing of the azithromycin molecules in this crystal form. In particular, the crystal habit favours interaction between the N and O atoms with the metal through one particular crystal face.

Re-Evaluation of Amino Acid Sequence and Structural Consensus Rules for Cysteine-Nitric Oxide Reactivity

Nitric oxide (NO), produced in different cell types through the conversion of Larginine into Lcitrulline by the enzyme NO synthase, has been proposed to exert its action in several physiological and pathological events. The great propensity for nitrosothiol formation and breakdown represents a mechanism which modulates the action of macromolecules containing NOreactive Cys residues at their active centre and/or allosteric sites. Based on the human haemoglobin (Hb) structure and accounting for the known acidbase catalysed Cys?93-nitrosylation and Cys?93NOdenitrosylation processes, the putative amino acid sequence (Lys/Arg/His/Asp/Glu)Cys(Asp/Glu) (sites 1, 0, and + 1, respectively) has been proposed as the minimum consensus motif for CysNO reactivity. Although not found in human Hb, the presence of a polar amino acid residue (Gly/Ser/Thr/Cys/Tyr/Asn/Gln) at the 2 position has been observed in some NOreactive protein sequences (e.g., NMDA receptors). However, the most important component of the tri or tetrapeptide consensus motif has been recognised as the Cys(Asp/Glu) pair [Stamler et al., Neuron (1997) 18, 691 696]. Here, we analyse the threedimensional structure of several proteins containing NOreactive Cys residues, and show that their nitrosylation and denitrosylation processes may depend on the CysS? atomic structural microenvironment rather than on the tri or tetrapeptide sequence consensus motif.