Browsing by Author "Polat, S"

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    Antigen-presenting cells in the hypertrophic pharyngeal tonsils
    Özbilgin, MK; Polat, S; Mete, UÖ; Tap, Ö; Kaya, M
    The antigen presenting cells (APCs) with special interest to dendritic cells (DC), were investigated in 28 hypertrophic and 10 control pharyngeal tonsils of children by histochemistry, immunohistochemistry and electron microscopy. In this study, we are trying to clarify the function and classification of APC in pharyngeal tonsils using morphologic criteria, Human Leukocyte Antigen Monoclonal Antibody (HLA-DR MoAb), which is specific for APCs, and acid phosphatase (APh) reacting with both phagosomes and lysosomes. The surface epithelium of the patient group examined by light microscopy, heavy infiltration of lymphocytes, degenerated columnar cells and a few 14LA-DR MoAb (+) columnar cells was observed. Additionally, a significant number of APCs which were Langerhans cells (LCs), interdigitating dendritic cell (IDC), follicular dendritic cell (FDC) and macrophages were stained with both HLA-DR MoAb and APh in the epithelial, interfollicular-subepithelial and follicular areas. Ultrastructural examinations revealed that lymphocytes, macrophages, LC and M cells were found among the surface columnar epithelial cells of the patient group. The interactions between M cells and LC suggested that M cells probably passed antigens from surface to LC. In the interfollicular-subepithelial areas of the hypertrophic pharyngeal tonsil, IDCs were in close contact with lymphocytes, macrophages and plasma cells. Seven types of FDCs (FDC-1 - FDC-7) were recognised according to their ultrastructural appearances. Differentiated FDCs (FDC-4) were also in close contact with each active subtype of FDCs in follicular areas besides lymphocytes. These findings supported the idea that although the pharyngeal tonsils contained several types of active APCs, only DC were in close contact with immunocompetent cells and the other APC's. Therefore, these morphologic appearances of DC could be a sign of function to initiate the immune response of the pharyngeal tonsil.
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    Nation-wide analysis of the impact of Covid-19 pandemic on daily urology practice in Turkey
    Bozkurt, O; Sen, V; Irer, B; Sagnak, L; Onal, B; Tanidir, Y; Karabay, E; Kaya, C; Ceyhan, E; Baser, A; Duran, MB; Suer, E; Celen, I; Selvi, I; Ucer, O; Karakoc, S; Sarikaya, E; Ozden, E; Deger, D; Egriboyun, S; Ongun, S; Gurboga, O; Asutay, MK; Kazaz, IO; Yilmaz, IO; Kisa, E; Demirkiran, ED; Horsanali, O; Akarken, I; Kizer, O; Eren, H; Ucar, M; Cebeci, OO; Kizilay, F; Comez, K; Mercimek, MN; Ozkent, MS; Izol, V; Gudeloglu, A; Ozturk, B; Akbaba, KT; Polat, S; Gucuk, A; Ziyan, A; Selcuk, B; Akdeniz, F; Turgut, H; Sabuncu, K; Kaygisiz, O; Ersahin, V; Kahraman, HI; Guzelsoy, M; Demir, O
    Objective To present a nation-wide analysis of the workload of urology departments in Turkey week-by-week during Covid-19 pandemic. Methodology The centres participating in the study were divided into three groups as tertiary referral centres, state hospitals and private practice hospitals. The number of outpatients, inpatients, daily interventions and urological surgeries were recorded prospectively between 9-March-2020 and 31-May-2020. All these variables were recorded for the same time interval of 2019 as well. The weekly change of the workload of urology during pandemic period was evaluated, also the workload of urology and the distributions of certain urological surgeries were compared between the pandemic period and the same time interval of the year 2019. Results A total of 51 centres participated in the study. The number of outpatients, inpatients, urological surgeries and daily interventions were found to be dramatically decreased by the 3rd week of pandemics in state hospitals and tertiary referral centres; however, the daily urological practice were similar in private practice hospitals throughout the pandemic period. When the workload of urology in pandemic period and the same time interval of the year 2019 were compared, a huge decrease was observed in all variables during pandemic period. However, temporary measures like ureteral stenting, nephrostomy placement and percutaneous cystostomy have been found to increase during Covid-19 pandemic compared with normal life. Conclusions Covid-19 pandemic significantly affected the routine daily urological practice likewise other subspecialties and priority was given to emergent and non-deferrable surgeries by urologists in concordance with published clinical guidelines.
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    Effects of High Altitude on Sleep and Respiratory System and Theirs Adaptations
    San, T; Polat, S; Cingi, C; Eskiizmir, G; Oghan, F; Cakir, B
    High-altitude (HA) environments have adverse effects on the normal functioning body of people accustomed to living at low altitudes because of the change in barometric pressure which causes decrease in the amount of oxygen leading to hypobaric hypoxia. Sustained exposure to hypoxia has adverse effects on body weight, muscle structure and exercise capacity, mental functioning, and sleep quality. The most important step of acclimatization is the hyperventilation which is achieved by hypoxic ventilatory response of the peripheral chemoreceptors. Hyperventilation results in increase in arterial carbondioxide concentration. Altitude also affects sleep and cardiac output, which is the other determinant of oxygen delivery. Upon initial exposure to HA, the resting pulse rate increases rapidly, but with acclimatization, heart rate and cardiac output tend to fall. Another important component that leads to decrease in cardiac output is the reduction in the stroke volume with acclimatization. During sleep at HA, the levels of CO2 in the blood can drop very low and this can switch off the drive to breathe. Only after the body senses a further drop in O-2 levels breathing is started again. Periodic breathing is thought to result from instability in the control system through the hypoxic drive or the response to CO2.