Neuroinflammation, Gut-Brain Axis and Depression

Alper Evrensel,Barış,Ö,nen Ü,nsalver,Mehmet Emin Ceylan 대한신경정신의학회 2020 PSYCHIATRY INVESTIGATION Vol.17 No.1

Psychiatric diseases are the manifestations that result from the individual’s genetic structure, physiology, immunology and ways of coping with environmental stressors. The current psychiatric diagnostic systems do not include any systematic characterization in regard to neurobiological processes that reveal the clinical picture in individuals who got psychiatric diagnosis. It is obvious that further research in different areas is needed to understand the psychopathology. The problems in the functions of immune system and the correlation of neuroinflammatory processes with psychiatric disorders have been one of the main research topics of psychiatry in recent years and have contributed to our understanding of psychopathology. Recent advances in the fields of immunology and genetics as well as rapidly increasing knowledge on the effects of immunological processes on brain functions have drawn attention to the correlations between psychiatric disorders and immune system dysfunctions. There are still unfilled gaps in the biology, pathophysiology, and treatment of major depressive disorder, which is quite prevalent among the psychiatric disorders, can lead to significant disability, and frequently has a recurrent course. It appears that low-grade chronic neuroinflammation plays a key role in forming a basis for the interaction between psychological stress, impaired gut microbiota and major depressive disorder. In this review, the role of neuroinflammation in the etiopathogenesis of depression and the mechanism of action of the gut-brain axis that leads to this are discussed in the light of current studies.

Fecal Microbiota Transplantation and Its Usage in Neuropsychiatric Disorders

Alper Evrensel,Mehmet Emin Ceylan 대한정신약물학회 2016 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.14 No.3

Fecal microbiota transplantation has a 1700-year history. This forgotten treatment method has been put into use again during the last 50 years. The interest in microbiota-gut-brain axis and fecal microbiota transplantation is rapidly increasing. New evidence is obtained in the etiopathogenesis of neuropsychiatric disorders. There is a large number of experimental and clinical researches in the field of gut-brain axis. There is limited information on fecal microbiota transplantation. Despite this, initial results are promising. It is commonly used in the treatment of gastrointestinal diseases such as Clostridium difficile infection, Crohn’s disease, ulcerative colitis. It is also experimentally used in the treatment of metabolic and autoimmune diseases. There are case reports that it is effective in the treatment of autism, Parkinson’s disease, multiple sclerosis, chronic fatigue syndrome and irritable bowel syndrome. Its implementation is easy, and it is a cheap and reliable treatment method. However, the long-term risks are unknown. Additionally, standard application protocols have not yet been established. There are a lot of questions to be answered. A university in Turkey has got official permission this year, and started to apply fecal microbiota transplantation. In this review, neuropsychiatric areas of use of fecal microbiota transplantation have been discussed in the light of the current information.

When is CPR Futile?

Alpers, Ann,Lo, Bernard MediMedia Korea 1995 JAMA-Korea Vol.10 No.5

The Effect of Terpenes on Percutaneous Absorption of Tiaprofenic Acid Gel

Alper Okyar,Maksat Nuriyev,Ayca Yildiz,Zeliha Pala-Kara,Narin Ozturk,Engin Kaptan 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.11

Tiaprofenic acid is a potent analgesic and nonsteroidal anti-inflammatory drug (NSAID) and like any other nonsteroidal anti-inflammatory drug, oral administration of the conventional dosage forms of tiaprofenic acid invariably causes gastrointestinal side effects. In an effort to eliminate these side effects while enhancing the drug concentration at the target tissue, an epidermal application of tiaprofenic acid seems to be an effective alternative drug delivery modality. This study attempts to demonstrate the influence of different terpenes (d-limonene, menthol and nerolidol) in various combinations of preparations on the percutaneous penetration of tiaprofenic acid from Carbopol® 940 based gel formulations (1%) in an ex vivo experiment using Franz-type diffusion cells. The enhancement effect of terpenes on skin absorption of tiaprofenic acid was further evaluated by an in vivo method in rats. Amongst the terpenes used, d-limonene was the most outstanding penetration enhancer that was reference to penetration of tiaprofenic acid through rat skin ex vivo. In vivo penetration study shows that the AUC0-48h was increased by about 10 fold by the addition of 5% d-limonene to the formulation. Histological studies show that d-limonene causes disruption on the skin surface and is responsible for enhanced penetration of tiaprofenic acid. Since tiaprofenic acid is known to cause gastrointestinal disturbances following systemic administration, topical formulations of tiaprofenic acid in gel form including 5% d-limonene could be suggested as an alternative.

Letters to the Editor : Bupropion-Induced Erythema Multiforme

( Alper Evrensel ),( Mehmet Emin Ceylan ) 대한피부과학회 2015 Annals of Dermatology Vol.27 No.3

Lightweight aggregates coated with colemanite

Alper Bideci,Özlem Sallı Bideci,Sabit Oymael,Ali Haydar Gültekin,Hasan Yıldırım 사단법인 한국계산역학회 2017 Computers and Concrete, An International Journal Vol.19 No.5

Technological advancements in the field of building materials are achieved day by day. In this study, a new lightweight concrete aggregate is produced by mixing certain rates of colemanite (0%, 7.5%, 12.5%, 17.5%), cement and coating the surface of pumice aggregate with this mixture. Thin aggregate sections are analyzed with specific gravity, unit weight, water absorption, impact, and crushing experiments. In this way, the production of cement and cement+colemanite coated lightweight concrete aggregates is investigated and an opinion on the likely behavior of these concrete types is provided.

The Gut-Brain Axis: The Missing Link in Depression

Alper Evrensel,Mehmet Emin Ceylan 대한정신약물학회 2015 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.13 No.3

The gut microbiota is essential to human health and the immune system and plays a major role in the bidirectional communication between the gut and the brain. Based on evidence, the gut microbiota is associated with metabolic disorders such as obesity, diabetes mellitus and neuropsychiatric disorders such as schizophrenia, autistic disorders, anxiety disorders and major depressive disorders. In the past few years, neuroscientific research has shown the importance of the microbiota in the development of brain systems. Recent studies showed that the microbiota could activate the immune and central nervous systems, including commensal and pathogenic microorganisms in the gastrointestinal tract. Gut microorganisms are capable of producing and delivering neuroactive substances such as serotonin and gamma-aminobutyric acid, which act on the gut-brain axis. Preclinical research in rodents suggested that certain probiotics have antidepressant and anxiolytic activities. Effects may be mediated via the immune system or neuroendocrine systems. Herein, we present the latest literature examining the effects of the gut microbiota on depression.

Small Size Autograft versus Large Size Allograft in Anterior Cruciate Ligament Reconstruction

Alper Kurtoğlu,Betül Başar,Gökhan Başar,Ömer Gezginaslan,Hakan Başar 대한정형외과학회 2021 Clinics in Orthopedic Surgery Vol.13 No.1

Background: A small autograft diameter negatively affects functional outcomes, knee stability, and the risk of rerupture after anterior cruciate ligament (ACL) reconstruction, whereas the strength of allograft decreases over time. Therefore, it is not clear whether the use of smaller autografts or the use of larger allografts in ACL yields better results. The aim of this study was to compare the outcome of smaller autografts and larger allografts for ACL reconstruction. Methods: Fifty-one patients who underwent ACL reconstruction with hamstring tendon autografts (size ≤ 8 mm) and 21 patients who underwent ACL reconstruction with allografts (size ≥ 10 mm) were included in our study. All patients underwent the same aggressive early postoperative rehabilitation program. There were no significant differences between the autograft and allograft groups regarding the preoperative patient age, sex, time from injury to surgery, and average follow-up time. Results: The mean diameter of the 4-stranded hamstring tendon grafts used as autografts was 7.48 ± 0.33 mm and the mean diameter of the allografts was 10.76 ± 0.67 mm. According to specific tests for the ACL (anterior drawer, Lachman, and pivot shift) and clinical evaluation tests (Lysholm knee scoring scale and International Knee Documentation Committee questionnaire), the final follow-up results were significantly better than the preoperative status in both autograft and allograft ACL reconstruction groups. Therefore, there were no significant differences between the autograft and allograft groups preoperatively and at the final follow-up. Conclusions: The large size of the graft in ACL reconstruction has been reported to affect results positively. However, in our study, we could not find any significant differences between the smaller size autografts and larger size allografts in terms of inadequacy, rerupture, and final follow-up functional results. Although allografts were significantly larger than autografts, we did not have the positive effect of larger size grafts. Smaller size autografts were as effective as the larger size allografts.

Nonlinear Fiber Modeling of Steel-Concrete Partially Composite Beams with Channel Connectors

Alper Ozturk,Eray Baran,Cenk Tort 대한토목학회 2019 KSCE Journal of Civil Engineering Vol.23 No.5

A simplified nonlinear fiber-based finite element model of steel-concrete partially composite beams utilizing channel type mechanical shear connectors is developed in OpenSees framework. The interaction between steel beam and concrete slab is accounted for by introducing nonlinear zero length elements and rigid links. The channel shear connector response used in numerical models is based on the previously obtained experimental response from pushout tests. Accuracy of the numerical models in predicting the response of beams is verified with the results of the previously conducted composite beam tests. The numerically predicted response agrees well with the experimental results over the entire range of load-deflection curves for both the fully composite and partially composite beams. The numerical models are also able to accurately predict the interface slip between steel beam and concrete slab when compared to the experimentally determined slip values, as well as the closed form slip predictions. Analysis results allowed the investigation of how the influence of steel and concrete damage is reflected on the overall loaddeflection response of composite beams.

Mechanical, Tensile Creep and Viscoelastic Properties of Thermoplastic Polyurethane/Polycarbonate Blends

Alper Kasgoz 한국섬유공학회 2021 Fibers and polymers Vol.22 No.2

This study investigated the morphological, mechanical and solid-state creep properties of thermoplasticpolyurethane/polycarbonate blends. Blend film samples were prepared via the solution-mixing method. The morphologicaland mechanical properties of the samples were investigated by scanning electron microscope (SEM) and universal testmachine. Solid-state creep tests were also performed by dynamic mechanic analyzer (DMA) under a stress value of 3 MPa atdifferent temperatures (30, 40, and 50 °C). Morphological observations indicated that the blend samples had a compatiblestructure due to the polar nature of PC and TPU. In the mechanical tests, it was found that the tensile modulus value improvedsignificantly by incorporation of PC, whereas the strain at break and toughness values reduced. Accordingly, the blendsample that contained PC at the rate of 10 % (wt.) showed a higher tensile modulus and lower toughness than neat TPU by2.85 and 0.56 times, respectively. In the creep strain analyses, the viscoelastic structure and long-term creep performance ofthe samples were analyzed by the Burger model, time-temperature superposition (TTS) approach and Findley model. Theexperimental values and the model predictions indicated that incorporation of PC into the TPU phase improved the creepresistance of TPU significantly. For example, the creep strain value of neat TPU could be reduced by 68 % and 98 % in therespective cases of the PC concentrations of 10 % (wt.) and 50 % (wt.). Finally, the experimental creep-recovery behavior ofthe samples was investigated, and the permanent strain values were determined by the Weibull Distribution Function (WDF).