Long Term Exposure to Myrtucommulone-A Changes CD105 Expression and Differentiation Potential of Mesenchymal Stem Cells

Kenan Izgi,Mehmet Fatih Sonmez,Halit Canatan,Banu Iskender 한국조직공학과 재생의학회 2017 조직공학과 재생의학 Vol.14 No.2

Mesenchymal stem cells (MSCs) represent a heterogeneous group of multipotent stem cells that could be found in various somatic tissues. MSCs are defined by molecular and functional features including spindle-shape morphology, adherence to plastic surfaces, expression of specific surface markers and differentiation potential to chondrocytes, adipocytes and osteocytes. The surface markers were proposed to affect the differentiation potential of MSCs by a limited number of studies. Endoglin (CD105) is defined to be a significant marker for osteogenic and chondrogenic differentiation ability of MSCs. Low CD105 expression is associated with increased osteogenic potential while high CD105 expression is correlated with strong chondrogenic potential. Myrtucommulone-A (MC-A) is an active compound with various biological effects on different cell types but its effect on MSC differentiation has not been described yet. In the present study we aimed at investigating the longterm effects of MC-A on hMSCs. MC-A-treatment reduced CD105 expression in distinct human mesenchymal stem cell (hMSC) lines and gave rise to CD105low population but did not change CD44, CD90 or CD73 expression. The decrease in CD105 expression reduced the chondrogenic potential of hMSCs subsequently while adipogenic or osteogenic differentiation was not affected dramatically. MC-A-treatment also suppressed the NF-jB p65 activation which might be responsible for the reduced chondrogenic potential. Our findings suggest thatMC-Acould be used to enrichCD105lowhMSCs without the need for cell sorting or changing culture conditions which could be utilised in targeted differentiation studies.

Relationship of Probable Attention Deficit Hyperactivity Disorder with Severity of Psychopathology and Impulsivity in a Sample of Male Patients with Opioid Use Disorder

Cuneyt Evren,Izgi Alniak,Vahap Karabulut,Turan Cetin,Gokhan Umut,Ruken Agachanli,Bilge Evren 대한신경정신의학회 2018 PSYCHIATRY INVESTIGATION Vol.15 No.2

ObjectiveaaThe aim of the present study was to evaluate relationship of probable attention deficit hyperactivity disorder (ADHD) with severity of psychopathology and the effect of impulsivity on this relationship in a sample of male patients with opioid use disorder (OUD). MethodsaaParticipants included 234 patients (115 inpatients and 119 outpatients) with OUD. Participants were evaluated with the Adult ADHD Self-Report Scale (ASRS-v1.1), the Symptom Checklist-90-R (SCL-90-R) and the Short Form of Barratt Impulsiveness Scale (BIS-11-SF). ResultsaaPsychopathology and impulsivity scores were higher among those with the probable ADHD. ADHD scores were midly to moderately correlated with impulsivity and psychopathology scores. In logistic regression analyses, while severity of general psychopathology and impulsivity predicted probable ADHD in the first Model, in the second Model, among dimensions of psychopathology obsessive compulsive (OC) dimension, whereas among dimensions of impulsivity non-planning and motor impulsivity predicted probable ADHD. ConclusionaaThese findings suggest that probable ADHD is related with the severity of psychopathology, particularly OC dimension, while the severity of impulsivity may have an partial mediator (particularly non-planning and motor impulsivity) effect on this relationship among patients with OUD.

Magnetic and Magnetocaloric Properties of (Gd<SUB>1-x</SUB>Ce<SUB>x</SUB>)Al<SUB>2</SUB> (x = 0, 0.25, 0.5, 0.75) Compounds

H. Gencer,T. Izgi,A. O. Kaya,S. Atalay,V. S. Kolat 한국자기학회 2011 Journal of Magnetics Vol.16 No.4

The magnetic and magnetocaloric properties of Gd1-xCexAl2 (x = 0, 0.25, 0.5, 0.75) intermetallic compounds alloys have been investigated in detail for the first time. XRD patterns indicated that all the samples were crystallized in a single phase with MgCu2-type structure (Laves phase). Ce substitution for Gd increased the lattice parameters and decreased the Curie temperature from 163 K for x = 0 to 37 K for x = 0.75. A maximum entropy change of 3.82 J/kg K was observed when a 2 T magnetic field was applied to the x = 0 sample. This entropy change decreased with increasing Ce content to 2.04 J/kg K for the x = 0.75 sample.

The Effects of Galantamine Hydrobromide Treatment on Dehydroepiandrosterone Sulfate and Cortisol Levels in Patients with Chronic Fatigue Syndrome

Tayfun Turan,Hasan Basri Izgi,Saliha Ozsoy,Fatih Tanrıverdi,Mustafa Basturk,Akif Asdemir,Aslı Beşirli,Ertugrul Esel,Seher Sofuoglu 대한신경정신의학회 2009 PSYCHIATRY INVESTIGATION Vol.6 No.3

Objective: Mental fatigue, cognitive disorders, and sleep disturbances seen in chronic fatigue syndrome (CFS) may be attributed to cholinergic deficit. A functional deficiency of cholinergic neurotransmission may cause the hypothalamic-pituitary-adrenal axis hypoactivity seen in CFS. Therefore, we investigated the alterations in stress hormones such as cortisol and dehydroepiandrosterone sulfate (DHEAS) in CFS patients before and after 4- week administration of galantamine hydrobromide, a selective cetylcholinesterase inhibitor, and aimed to investigate whether there are any relationships between the probable hormonal changes and cholinergic treatment. Methods: Basal levels of cortisol and DHEAS were measured in 29 untreated CFS patients who were diagnosed according to Centers for Disease Control (CDC) criteria and in 20 healthy controls. In the patient group, four weeks after 8 ㎎/d galantamine hydrobromide treatment, cortisol and DHEAS levels were measured again. After the treatment 22 patients who stayed in study were divided into two subgroups as responders and nonresponders according to the reduction in their Newcastle Research Group ME/CFS Score Card (NRG) scores. Results: Important findings of this study are lower pre-and post-treatment cortisol levels and in all CFS patients compared to controls (F=4.129, p=0.049; F=4.803, p=0.035, respectively); higher basal DHEAS values and higher DHEAS/cortisol molar ratios which were normalized following four weeks’ treatment with 8 ㎎/d galantamine hydrobromide in the treatment-respondent group (F=5.382, p=0.029; F=5.722, p=0.025, respectively). Conclusion: The findings of the decrease in basal DHEAS levels and DHEAS/cortisol molar ratios normalizing with galantamine treatment may give some support to the cholinergic deficit hypothesis in CFS. Objective: Mental fatigue, cognitive disorders, and sleep disturbances seen in chronic fatigue syndrome (CFS) may be attributed to cholinergic deficit. A functional deficiency of cholinergic neurotransmission may cause the hypothalamic-pituitary-adrenal axis hypoactivity seen in CFS. Therefore, we investigated the alterations in stress hormones such as cortisol and dehydroepiandrosterone sulfate (DHEAS) in CFS patients before and after 4- week administration of galantamine hydrobromide, a selective cetylcholinesterase inhibitor, and aimed to investigate whether there are any relationships between the probable hormonal changes and cholinergic treatment. Methods: Basal levels of cortisol and DHEAS were measured in 29 untreated CFS patients who were diagnosed according to Centers for Disease Control (CDC) criteria and in 20 healthy controls. In the patient group, four weeks after 8 ㎎/d galantamine hydrobromide treatment, cortisol and DHEAS levels were measured again. After the treatment 22 patients who stayed in study were divided into two subgroups as responders and nonresponders according to the reduction in their Newcastle Research Group ME/CFS Score Card (NRG) scores. Results: Important findings of this study are lower pre-and post-treatment cortisol levels and in all CFS patients compared to controls (F=4.129, p=0.049; F=4.803, p=0.035, respectively); higher basal DHEAS values and higher DHEAS/cortisol molar ratios which were normalized following four weeks’ treatment with 8 ㎎/d galantamine hydrobromide in the treatment-respondent group (F=5.382, p=0.029; F=5.722, p=0.025, respectively). Conclusion: The findings of the decrease in basal DHEAS levels and DHEAS/cortisol molar ratios normalizing with galantamine treatment may give some support to the cholinergic deficit hypothesis in CFS.

Some Approximation Results by Bivariate Bernstein-Kantorovich Type Operators on a Triangular Domain

Resat Aslan,Aydin Izgi 경북대학교 자연과학대학 수학과 2022 Kyungpook mathematical journal Vol.62 No.3

In this work, we define bivariate Bernstein-Kantorovich type operators on a triangular domain and obtain some approximation results for these operators. We start off by computing some moment estimates and prove a Korovkin type convergence theo rem. Then, we estimate the rate of convergence using the partial and complete modulus of continuity, and derive a Voronovskaya-type asymptotic theorem. Further, we calculate the order of approximation with regard to the Peetre’s K-functional and a Lipschitz type class. In addition, we construct the associated GBS type operators and compute the rate of approximation using the mixed modulus of continuity and class of the Lipschitz of Bogel continuous functions for these operators. Finally, we use the two operators to approximate example functions in order to compare their convergence.

A Malignant Transformation of a Spinal Epidural Mass from Ganglioneuroblastoma to Neuroblastoma

Akcakaya, Mehmet Osman,Bilgic, Bilge,Aras, Yavuz,Izgi, Nail The Korean Neurosurgical Society 2015 Journal of Korean neurosurgical society Vol.57 No.3

Ganglioneuromas are benign tumors. Surgical excision is the treatment of choice with very good prognosis. However, neuroblastomatous malignant transformation of ganglioneuromas was previously reported. We report a patient with spinal neuroblastoma recurrent from a ganglioneuroblastoma after disease free survival of 13 years. This is one of the rare examples of spinal neuroblastoma and to our knowledge the second case report with malignant transformation from a ganglioneuroblastoma or a ganglioneuroma. The present case is the only report in the literature with further genetic investigations.

Electrical Transport and Magnetoresistance of La<SUB>0.67</SUB>Ca<SUB>0.33</SUB>MnO<SUB>3</SUB>: Ag<SUB>x</SUB>(x = 0, 0.1, 0.2, 0.3, 0.4) Composites

H. Gencer,M. Pektas, Y. Babur,V. S. Kolat,T. Izgi,S. Atalay 한국자기학회 2012 Journal of Magnetics Vol.17 No.3

The structural, magnetic and magnetotransport properties of La0.67Ca0.33MnO3: Agx (x = 0, 0.1, 0.2, 0.3 and 0.4) composites were investigated systematically. X-ray and EDX analysis indicated that Ag is not substituted into the main La0.67Ca0.33MnO3 phase and remains an additive to the second phase at the grain boundary. The Curie temperature first decreased from 269 K for x = 0 to 257 K for x = 0.1 and then remained nearly unchanged with increasing Ag content. For the x > 0.1 samples, a second transition temperature (TMI2) was observed in the resistance curves. At temperatures below 150 K, a significant enhancement in MR was observed while high temperature MR decreased with increasing Ag content. The maximum MR was observed to be 55% in the x = 0.4 sample at 10 K and a 6T magnetic field, this value is larger than that of pure La0.67Ca0.33MnO3 (53% at 265 K and 6 T). In addition, at low fields (H < 1T), a sharp increase in the MR was observed.

Effect of Fe Substitution on Magnetic and Magnetocaloric Properties of La<SUB>0.94</SUB>Bi<SUB>0.06</SUB>Mn<SUB>1-x</SUB>Fe<SUB>x</SUB>O₃ (x = 0, 0.05, 0.075 and 0.1) Compounds

H. Gencer,V. S. Kolat,N. Bayri,T. Izgi,S. Atalay 한국자기학회 2017 Journal of Magnetics Vol.22 No.3

The effects of Fe doping on structural, magnetic and magnetocaloric properties of La0.94Bi0.06Mn1-xFexO₃ (x = 0, 0.05, 0.075, 0.1) compounds were investigated. X-ray analyses showed that the substitution of Mn by Fe produced no major structural change. It was found that the saturation magnetization, Curie temperature and maximum value of magnetic entropy change decrease with increasing Fe content. The decrease in magnetic entropy change was attributed to the decrease in saturation magnetization and the nature of phase transition transforms from first-order to second-order. The refrigeration capacities were determined to be 259 and 230 J/kg for the x = 0 and 0.075 samples, respectively at a field change of 5 T.

Magnetic and Magnetocaloric Properties of Pr₂Fe<SUB>17-x</SUB>Cu<SUB>x</SUB> Intermetallic Compounds

N. E. Cengiz,M. Pektas,V. S. Kolat,T. Izgi,H. Gencer,N. Bayri,S. Atalay 한국자기학회 2021 Journal of Magnetics Vol.26 No.3

In this study, Cu-doped intermetallic compounds with the chemical composition of Pr₂Fe17-xCux (x = 0, 0.1, 0.2) were prepared by the arc-melting process. SEM analysis revealed that the samples consist of irregularly shaped and strongly connected micron-scale particles range from 0.5 μm to 4 μm. EDX analysis showed that all the samples consist of a single phase. The magnetic measurements revealed that all the samples exhibit a ferromagnetic to the paramagnetic phase transition. The Curie temperature was determined to increase linearly with increasing Cu substitution from 286 K for x = 0 to 303 K for x = 0.2. The maximum value of magnetic entropy change |ΔSm| was estimated from isothermal magnetization curves and it decreases with increasing Cu content from 5.63 J/kg·K for x = 0 to 4.21 J/kg·K for x = 0.2 at 5 T magnetic field change. At the same magnetic field change, the relative cooling power values range from 404.8 J/Kg for x = 0 to 248.3 J/Kg for x = 0.2. Arrott plots and Landau analyses revealed that all the samples show second-order magnetic phase transition.