Studies on Sorption and Release of Doxycycline Hydrochloride from Zwitterionic Microparticles with Carboxybetaine Moieties.

The aim of this study was to examine the use of zwitterionic microparticles as new and efficient macromolecular supports for the sorption of an antibiotic (doxycycline hydrochloride, DCH) from aqueous solution. The effect of relevant process parameters of sorption, like dosage of microparticles, pH value, contact time, the initial concentration of drug and temperature, was evaluated to obtain the optimal experimental conditions. The sorption kinetics were investigated using Lagergren, Ho, Elovich and Weber-Morris models, respectively. The sorption efficiency was characterized by applying the Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. The calculated thermodynamic parameters (ΔH, ΔS and ΔG) show that the sorption of doxycycline hydrochloride onto zwitterionic microparticles is endothermic, spontaneous and favorable at higher temperatures. The maximum identified sorption capacity value is 157.860 mg/g at 308 K. The Higuchi, Korsmeyer-Peppas, Baker-Lonsdale and Kopcha models are used to describe the release studies. In vitro release studies show that the release mechanism of doxycycline hydrochloride from zwitterionic microparticles is predominantly anomalous or non-Fickian diffusion. This study could provide the opportunity to expand the use of these new zwitterionic structures in medicine and water purification.

Clinical, Epidemiological, Morphological, and Immunohistochemical Aspects of Nasopharyngeal Carcinoma-4-Year Retrospective Study in the Western Part of Romania.

Nasopharyngeal carcinoma is one of the most common malignant tumors in the head and neck region. The carcinogenesis is a complex process stimulated by many factors. Although the etiological factors and pathogenic mechanisms are not elucidated, the genetic susceptibility, environmental factors, and association with latent infection with Epstein-Barr Virus play an important role. The aim of this study was to present the main clinical and epidemiological data, as well as the morphological aspects and the immunohistochemical profile, of patients with nasopharyngeal carcinoma diagnosed in western Romania. The study was retrospective and included 36 nasopharyngeal carcinomas. The histopathological diagnosis was completed using immunohistochemical reactions for the following antibodies: p63, p53 and p16 protein, cytokeratins (CK) AE1/AE3, CK5, CK7, CK20 and 34ßE12, epithelial membrane antigen (EMA), Epstein-Barr virus (EBV), leukocyte common antigen (LCA), CD20, CD4, CD8, CD68, CD117, and CD1a. The squamous malignant component of nasopharyngeal carcinoma presented with positivity for cytokeratins AE1/AE3, CK5, 34ßE12, and p63. Undifferentiated nasopharyngeal carcinoma was positive for EMA in 67% of cases, and 28% of cases showed an immunoreaction for CD117 in the malignant epithelial component. Also, the p53 protein was positive in all the cases. One case of undifferentiated nasopharyngeal carcinoma was p16-positive, and two cases were positive for EBV. A peri- and intratumor cellular infiltrate rich in lymphocytes, with a predominance of CD20-positive B lymphocytes, interspersed with T lymphocytes, was observed. The T cells were CD4- and CD8-positive, predominantly intratumoral, and the CD4:CD8 ratio was 1:1 for 75% of the undifferentiated subtype and 89% for differentiated non-keratinized squamous cell carcinoma. All subtypes of nasopharyngeal carcinoma presented with an inflammatory infiltrate with numerous plasma cells, eosinophils, and dendritic cells, presenting as antigen CD1a- and CD68-positive, as well as in CD117-positive mast cells.

Porous Crosslinked Zwitterionic Microparticles Based on Glycidyl Methacrylate and N-Vinylimidazole as Possible Drug Delivery Systems.

Crosslinked porous microparticles have received great attention as drug delivery systems lately due to their unique set of properties: the capability to form various polymer-drug combinations, low immunogenicity, patient compliance and ability to release drugs in a delayed or controlled manner. Moreover, polymers with betaine groups have shown some unique features such as antifouling, antimicrobial activity, biocompatibility and strong hydration properties. Herein, novel porous zwitterionic microparticles were prepared in two stages. The first step involves the synthesis of porous microparticles based on glycidyl methacrylate, N-vinylimidazole and triethyleneglycol dimethacrylate using the suspension polymerization technique, the second step being the synthesis of zwitterionic porous microparticles by polymer-analogous reaction in presence of sodium monochloroacetate as betainization agent. Both types of microparticles were characterized structurally and morphologically by FT-IR spectroscopy, energy dispersive X-ray analysis, scanning electron microscopy, dynamic vapors sorption and mercury porosimetry. The tetracycline loading into crosslinked and zwitterionic microparticles was also performed, the maximum tetracycline loading capacities being 87 mg/g and 135 mg/g, respectively. The drug release mechanism, elucidated by various mathematical models, is controlled by both diffusion and swelling processes as a function of the zwitterionic and/or porous microparticle structure. Both types of microparticles presented antibacterial activity against the two reference strains used in this study: Escherichia coli and Staphylococcus aureus.

Forecasting the Romanian Unemployment Rate in Time of Health Crisis-A Univariate vs. Multivariate Time Series Approach.

Economic crises cause significant shortages in disposable income and a sharp decline in the living conditions, affecting healthcare sector, hitting the profitability and sustainability of companies leading to raises in unemployment. At micro level, these sharp decreases in earnings associated with unemployment and furthermore with the lack of social protection will impact the quality of life and finally the health of individuals. In time of crisis, it becomes vital to support not only the critical sectors of the economy, the assets, technology, and infrastructure, but to protect jobs and workers. This health crisis has hit hard the jobs dynamics through unemployment and underemployment, the quality of work (through wages, or access to social protection), and through the effects on specific groups, with a higher degree of vulnerability to unfavorable labor market outcomes. In this context, providing forecasts as recent as possible for the unemployment rate, a core indicator of the Romanian labor market that could include the effects of the market shocks it becomes fundamental. Thus, the paper aims to offer valuable forecasts for the Romanian unemployment rate using univariate vs. multivariate time series models for the period 2021-2022, highlighting the main patterns of evolution. Based on the univariate time series models, the paper predict the future values of unemployment rate based on its own past using self-forecasting and implementing ARFIMA and SETAR models using monthly data for the period January 2000-April 2021. From the perspective of multivariate time series models, the paper uses VAR/VECM models, analyzing the temporal interdependencies between variables using quarterly data for the period 2000Q1-2020Q4. The empirical results pointed out that both SETAR and VECM provide very similar results in terms of accuracy replicating very well the pre-pandemic period, 2018Q2-2020Q1, reaching the value of 4.1% at the beginning of 2020, with a decreasing trend reaching the value of 3.9%, respectively, 3.6% at the end of 2022.

Polybetaines in Biomedical Applications.

Polybetaines, that have moieties bearing both cationic (quaternary ammonium group) and anionic groups (carboxylate, sulfonate, phosphate/phosphinate/phosphonate groups) situated in the same structural unit represent an important class of smart polymers with unique and specific properties, belonging to the family of zwitterionic materials. According to the anionic groups, polybetaines can be divided into three major classes: poly(carboxybetaines), poly(sulfobetaines) and poly(phosphobetaines). The structural diversity of polybetaines and their special properties such as, antifouling, antimicrobial, strong hydration properties and good biocompatibility lead to their use in nanotechnology, biological and medical fields, water remediation, hydrometallurgy and the oil industry. In this review we aimed to highlight the recent developments achieved in the field of biomedical applications of polybetaines such as: antifouling, antimicrobial and implant coatings, wound healing and drug delivery systems.

Conventional grade 1 chondrosarcoma: a challenging diagnosis with important implications on therapy and prognosis.

Chondrosarcoma (CHS) is a malignant tumor of soft tissue with cartilaginous differentiation that represent one tenth of all malignant proliferations developed from bone tissues. Even if CHS represents the third malignancy with bone localization, after myeloma and osteosarcoma, it is far less diagnosed in the head and neck region. The current paper presented two cases of conventional CHSs, which were diagnosed in Department of Thoracic Surgery and Department of Otorhinolaryngology of Emergency City Hospital, Timisoara, Romania, between February and June 2021. The malignant cases were of peripheral CHSs, one of scapula, and the other one had an extremely rare tracheal location with microscopic features of conventional low-grade tumors (grade 1). In all cases, conservative surgical curative treatment was performed, with a favorable postoperative evolution.