Rostro-caudal gradient in the expression of transcriptional factor SOX2 in the fetal human brain

Транскрипционният фактор Sox2 е ключов компонент в мрежа от гени, които контролират съдбата на различни видове стволови и прогениторни клетки в развиващия се мозък. Доказана е неговата важна роля за самообновяване и поддържане мултипотентността на ембрионалните неврални прогенитори при редица видове бозайници. Данните за експресията и функцията на Sox2 в човешкия фетален мозък обаче са твърде недостатъчни и противоречиви. В настоящото изследване беше проучена експресията и проследена динамиката на Sox2 в ростро-каудална посока в човешки фетален теленцефалон през 20-та гестационна седмица (г.с.). Чрез стандартна имунофлуоресцентна методика бяха визуализирани позитивните за този транскрипционен фактор клетки. Техният брой и относителен дял беше определен и след това сравнен между специфичните герминативни зони и на интересуващите ни нива и дялове на феталната крайномозъчна кора. Проучвайки експресията на Sox2 в трите основни герминативни зони на човешкия теленцефалон (вентрикулна, вътрешна субвентрикулна и външна субвентрикулна зона), установихме значителна разлика в броя на позитивните клетки в предно-задно направление. От рострално към каудално делът на Sox2 позитивните клетки във вентрикулната зона не показва съществена промяна, във вътрешната субвентрикулна зона има значително намаление, a при външнатa субвентрикулна зона има леко увеличение. Описаните различия във връзка с експресията на транскрипционния фактор Sox2 имат значение за пo-добрo разбиране на процесите на развитие, диференциация и миграция на невралните стволови/прогениторни клетки в крайния мозък при човека по време на феталната неврогенеза при нормални и патологични условия.Transcriptional factor Sox2 is a key component in a network of genes controlling the faith of diverse types of stem and progenitor cells in the developing brain. Its important role in self-renewal and maintenance of multipotency of embryonic neural progenitors is well established in a number of mammalian species. However, the data about the expression and function of Sox2 in the human fetal brain are scarce and controversial. In the present investigation, we studied Sox2 expression and its rostro-caudal dynamics in human telencephalon at 20th gestational week. Using a standard immunofluorescence technique positive cells for this transcriptional factor were visualized. Their numbers and relative portion were determined and compared in specific germinal zones at various levels and in different areas of the telencephalic cortex. When studying Sox2 expression we discovered significant differences in the numbers of positive cells in all three germinal zones (ventricular, inner subventricular and outer subventricular) in rostro-caudal direction. From rostrally to caudally the relative portion of Sox2 positive cells in the ventricular zone did not showed a significant change, in the inner subventricular zone there was a significant reduction and in the outer subventricular zone there was a slight increase. The differences described in the expression of transcriptional factor Sox2 may be of significance for a better understanding of processes related to the development, differentiation and migration of neural stem/progenitor cells in the human telencephalon during fetal neurogenesis in normal and pathological conditions

Cellular proliferation in the cortex of postischemic cerebellum by primates

Клетъчно-тъканните механизми на увреждане и възстановяване след мозъчна исхемия имат фундаментално приложно значение. Целта на настоящото проучването беше да установим промени в клетъчната пролиферация чрез бромодеоксиуридин (BrdU), индикатор за ДНК синтеза, при новородени, едногодишни и половозрели в млада възраст японски маймуни (Macaca fuscata) след глобална мозъчна исхемия на малкия мозък. Според възрастта, схемата на приложение на BrdU (2 дена х 250 mg/kg или 5 дена х 100 mg/kg i.v.) и срока на преживяемост след исхемията (съответно 4, 9 и 15 дни) животните бяха разпределени в няколко контролни и експериментални групи. Приложихме имунохистохимично оцветяване с пероксидаза на замразени срези от малкия мозък на изследваните животни за изтъкване на пролиферативния маркер BrdU. При сравнение на количеството BrdU+ клетки в малкомозъчната кора между групите на новородени, едногодишни и възрастни животни без исхемия се установи, че с увеличаване на възрастта пролиферативните процеси значително намаляват до относително слабо изразено поддържащо ниво. При сравнение между групите на възрастните животни с различна продължителност на исхемия се оказа, че тя е важен фактор, стимулиращ клетъчната пролиферация, като този ефект намалява с времето след исхемията. Предстои фенотипизиране на BrdU+ клетки, за да се определят видовете новообразувани клетки и тяхното съотношение в кората на малкия мозък след исхемията. Получените данни ще допълнят и разширят разбирането за възстановителните процеси след исхемично увреждане на малкия мозък при изследваните примати.Tissue and cellular mechanisms of damage and restoration аfter brain ischemia have fundamental as well as practical significance. The goal of the present study was to determine changes in cellular proliferation by bromodeoxyuridin (BrdU), indicator of DNA synthesis, in the cerebellum of newborn, one year old and adult Japanese monkeys (Macaca fuscata) after global brain ischemia. According to the age, BrdU paradigm (2 days х 250 mg/kg i.v. or 5 days х 100 mg/kg) and survival period after ischemia (4, 9 and 15 days correspondingly) the animals were distributed in several control and experimental groups. We applied immunohistochemical staining with peroxidase on frozen sections from cerebella of the monkeys examined to demonstrate the proliferative marker BrdU. Сomparison of thе аmount of BrdU+ cells in cerebellar cortex between non-ischemic control groups of different age showed a significant age dependent decline in the proliferative processes acheaving a relatively low supporting level. Comparison between groups of adult monkeys, subjected to ischemia with different duration, indicated that it is an important factor which induced cellular proliferation in the cerebellum but this effect declined with the time after ischemia. A forthcoming phenotyping of BrdU+ cells will differentiate between types of newborn cells and their relationship in the postischemic cerebellar cortex. The data acquired may expand and enlarge the understanding about restorative processes after ischemic injury to the cerebellum in the primates examined

Еxpression of transcriptional factors PAX2 and PAX6 in primate cerebellum related to the age and following ischemiа

Гените от фамилията Pax играят важна роля в пролиферацията на множествени клетъчни линии, при формирането на различни органи, включително в развитието и организацията на нервната система. В последно време беше установено значението на два транскрипционни фактора (ТФ) от тази група - pax2 и pax6 в тъканната регенерация и специално за Pax6 гена - нова функция в сегментната организация на задния мозък (Metencephalon).Целта на настоящото изследване беше да проучим присъствието, разпределението и динамиката на тези два ТФ в малкия мозък на новородени, едногодишни и половозрели в млада възраст японски маймуни (Macaca fuscata), при последните и след глобална мoзъчната исхемия. Според възрастта (новородени, едногодишни и възрастни) и срока на преживяемост след исхемията при възрастните (съответно 9 или 15 дни) животните бяха разпределени в няколко контролни и експериментални групи. Приложихме флуоресцентна имунохистохимична техника за оцветяване на замразени срези от малкия мозък за изтъкване на pax2 и pax6.При новородените животни единични Pax2(+) клетки се откриват предимно във вътрешния зърнест слой на малкия мозък и в слоя на клетките на Пуркиние. В по-късна възраст количеството им значително намалява. В групите с исхемия единични Pax2(+) клетки се разполагат в слоя на клетките на Пуркиние и зърнестия слой без разлика в местоположението и количеството в сравнение с контролите.Pax6(+) клетки се откриват в големи количества във всички слоеве на кората на малкия мозък при новородени животни, докато при едногодишните маймуни такива клетки се установяват основно във вътрешния зърнест слой. При възрастните животни от контролната група типичната им локализация е само в зърнестия слой без разлика в сравнение с групите с исхемия.Получените данни потвърждават и допълват достъпната информация относно наличието и типичното разпределение на тези два ТФ в малкия мозък в хода на развитието, без да се установяват промени след глобална мозъчна исхемия.The genes of Pax family play important roles in the proliferation of multiple cell lines, formation of various organs, including the development and organization of the central nervous system. Lately, it was found the significance of two transcriptional factors (ТFs) of this group - pax2 and pax6 in tissue regeneration, especially for Pax6 gene - a novel function in the segmental organization of the hindbrain.The goal of the present investigation was to study the presence, distribution and dynamics of these two TF in the cerebella of newborn, one-year old and young adult Japanese monkeys (Macaca fuscata), by the latter also after global brain ischemia. According to the age (newborn, one-year old and adult) and period of survival time after ischemia by the adults (9 or 15 days respectively), animals ware distributed in several control and experimental groups. We applied fluorescent immunohistochemical technique for staining cryo-sections of cerebellum for demonstration of pax2 and pax6.By the newborn animals Pax2(+) cells were found mainly in the inner granular cell layer of the cerebellum and in the layer of Purkinje cells. At later age their quantity was reduced. In the ischemic groups single Pax2(+) cells were located in the Purkinje cell layer and granular cell layer without difference in the location and amount compared with controls.Pax6(+) cells were found in large amount in all layers of the cerebellar cortex by newborn animals, whereas by one-year old monkeys such cells were found mainly in the inner granular layer. By adult animals of the control group their typical location was only in the granular layer, there was no difference in comparison with the ischemic groups.The data received conferm and expand the available information related to the presence and typical distribution of these two ТFs in the cerebellum in the course of postnatal development without establishment of changes following global brain ischemia

Reduction of Liver Iron Load in Adult Patients with β-Thalassemia Major Treated with Modern Chelation Modalities

Background: Management of beta-thalassemia major (TM) requires life-long hemotransfusions leading to iron overload. Iron elimination is enhanced by the use of modern chelators. Aim: To assess the effect of modern chelation therapy by dynamics of serum ferritin concentration and liver MRI T2*.Patients and methods: Forty-six patients with TM (male to female ratio =1:1, mean age 33.2±10.9 years) were prospectively studied between 2011 and 2014. Twenty-one patients (45.7%) were treated with deferasirox, 17 (37%) – with deferiprone, and 8 (17.3%) – with deferiprone in combination with deferoxamine. Ferritin was measured by ELISA. MRI T2* was assessed by Siemens Magnetom Avanto 1.5T. The patients were allocated into 3 groups based on their initial ferritin level and liver MRI T2*. Statistical analysis was performed using SPSS v. 18 for Windows. Data were analysed by descriptive analysis, analysis of variance and correlative analysis, means were compared using t-test and one-way ANOVA.Results: In 2011, 9 (19.5%) patients had normal liver MRI T2*; in 2014 they were 17 (37%). The patients with mild grade liver siderosis were 12 (26%) in 2011, and in 2014 they were 14 (30.4%). In 2011, the patients with moderate liver siderosis were 14 (30.4%), and in 2014 – 12 (26.0%). Eleven patients (23.9%) had severe liver siderosis in 2011 and only two patients (4.0%) were diagnosed with the condition in 2014.Conclusion: A reduction of iron overload was found in all studied groups. This positive effect is attributed to the use of modern chelators and the ease of access to accurate monitoring

Clinical characteristics, disease evolution and survival in patients with chronic myeloid leukemia, BCR-ABL1 (+) and T315I mutation.

Introduction: The T315I mutation in patients with chronic myeloid leukemia (CML) has been associated with therapeutic resistance and an unfavourable prognosis.Aim: To study the frequency of T315I mutation in patients with CML, BCR-ABL (+), their clinical characteristics, disease evolution, and median survival.Patients and methods: We studied 75 patients with CML and BCR-ABL1 (+). T315I mutation was detected by digital droplet PCR and BCR-ABL1 was analyzed by RT-PCR. A comparative analysis was performed by sex, age, disease phase, risk group, treatment, molecular response (MR), and median survival in T315I (+) and T315I (−) patients.Results: T315I mutation was detected in 11 patients (14.7%). No significant difference was found in the phase, risk group, and first-line therapy. A significantly higher proportion of T315I (+) did not achieve MR >3.5 log: 8 (72.7%) vs. 22 (34.4%) (p=0.023). The lowest mean BCR-ABL1 levels were significantly higher in the CML T315I (+) group compared to the CML T315I (−) group: 12.1±6.0 vs. 3.77±1.28 (p=0.009). The median survival of T315I (+) patients was significantly shorter: 73 months vs. 175 months (p<0.0001, CI 95%).Conclusions: Our data confirm the world experience on the frequency of T315I mutation, including the unfavourable evolution, resistance to TKI treatment and short survival. ddPCR is a highly sensitive method for early detection of genetic mutations which gives the chance for effective treatment

Analysis of the pharmacotherapeutic effectiveness of the tyrosine kinase inhibitors therapy in patients with Chronic Myeloid Leukemia in a single hematology center in Plovdiv, Bulgaria

Aim. The aim of this study is to evaluate treatment retrospectively, response to the therapy and outcomes in patients with chronic myeloid leukemia (CML) and to what extent the European recommendations of LeukemiaNET (ELN) are followed at the Hematology Clinic, University Hospital “St. Georgi”, MU Plovdiv. Methods. All patients with Ph+, BCR-ABL1+ CML who were treated and observed between 01.01.2018 and 12.31.2022 at the clinic were included in the study and were analyzed retrospectively. Results. One hundred and eighty-eight patients with a mean age of 61.26 (21–91) years were analyzed. 151 (80.3%) were in chronic phase (CP), 27 (14.4%) in accelerating one and 10 (5.3%) in blast crisis. The actual overall survival rate was 79.26%, while for CP it is very high – 86.75%, and the mortality rate is 20.74%. All patients received some form of tyrosine kinase inhibitors therapy (TKIs-therapy). The first line TKI was imatinib in 120 patients (64%), and 68 (36%) received a second-generation TKI. Treatment response was monitored with TKIs by RT-qPCR. Conclusion. CML patients treated in the hematology clinic receive standard care in accordance with ELN and BMSH recommendations. Overall survival (OS) in routine care is comparable to published data from international studies. Molecular monitoring provides a good basis for disease control in CP. There are unmet needs in the treatment of patients in advanced stages