Application of fiber loop ringdown spectroscopy technique for a new approach to beta-amyloid monitoring for Alzheimer Disease's early detection.

A novel fiber optic biosensor was purposed for a new approach to monitor amyloid beta protein fragment 1-42 (Aß42) for Alzheimer's Disease (AD) early detection. The sensor was fabricated by etching a part of fiber from single mode fiber loop in pure hydrofluoric acid solution and utilized as a Local Optical Refractometer (LOR) to monitor the change Aß42 concentration in Artificial Cerebrospinal Fluid (ACSF). The Fiber Loop Ringdown Spectroscopy (FLRDS) technique is an ultra-sensitive measurement technique with low-cost, high sensitivity, real-time measurement, continuous measurement and portability features that was utilized with a fiber optic sensor for the first time for the detection of a biological signature in an ACSF environment. Here, the measurement is based on the total optical loss detection when specially fabricated sensor heads were immersed into ACSF solutions with and without different concentrations of Aß42 biomarkers since the bulk refractive index change was performed. Baseline stability and the reference ring down times of the sensor head were measured in the air as 0.87% and 441.6µs ± 3.9µs, respectively. Afterward, the total optical loss of the system was measured when the sensor head was immersed in deionized water, ACSF solution, and ACSF solutions with Aß42 in different concentrations. The lowest Aß42 concentration of 2 ppm was detected by LOR. Results showed that LOR fabricated by single-mode fibers for FLRDS system design are promising candidates to be utilized as fiber optic biosensors after sensor head modification and have a high potential for early detection applications of not only AD but possibly also several fatal diseases such as diabetes and cancer.

Dose-related effects of ciproxifan on brain tissue in rats with cerebral ischemia-reperfusion.

PURPOSE: Cerebral ischemia is the result of decreased or interrupted blood flow to the brain. It is the third leading cause of death after cardiovascular disease and cancer. Cerebral ischemia is reversible or irreversible in neurons in the affected area, and subsequent free radical damage can be exacerbated if reperfusion occurs. Ciproxifan is used to study the involvement of histaminergic neurons in different phases such as wakefulness and cognition. We wanted to find out whether ciproxifan has a protective effect on the brain of rats with cerebral ischemia-reperfusion injury. MATERIALS AND METHODS: A total of 64 adult rats (32 male and 32 female) were used for the experiment. Eight cages were formed with randomly selected rats. No substance was administered to the rats in Group 1 and no surgical procedure was performed. The cerebral ischemia-reperfusion model (clamping of the left common carotid artery for 15 min followed by reperfusion for 24 h) was applied to rats in Group 2, Group 3, and Group 4 after 7 days/single dose of saline and ciproxifan (10 mg/kg, 30 mg/kg). After that, the activitymeter, forced swim test (FST), and Morris water maze (MWM) were performed on all animals. RESULTS: Rats treated with ciproxifan exhibit neurons and glial cells with histologic structures similar to those of the control group, and interestingly, these differences became more pronounced with increasing dose. Rats administered ciproxifan improved motor coordination, decreased total distance behavior, and improved learning ability. However, when the groups were compared by sex, no significant difference was found in the parameters. CONCLUSION: Thus, we could conclude that ciproxifan has a protective effect on the brain to a certain extent, regardless of the dose.

Cerebral ischemia is one of the leading causes of death.Cerebral ischemia is a common mechanism of acute brain injury that results from impaired blood flow to the brain.Ciproxifan is a well-investigated histamine H3 receptor inverse agonist/antagonist.Ciproxifan presynaptically inhibits glutamate release in rat hippocampus.

Vitamin A could be a Therapeutic Agent in Ischemia/Reperfusion Induced Kidney Injury / La vitamina A podría ser un agente terapéutico en la lesión renal inducida por isquemia/reperfusión

ABSTRACT Introduction: Renal ischemia (I) could develop due to decreased or ceased blood flow to the kidney in some clinical conditions such as shock, sepsis, and kidney transplantation. The re-supply of blood to the kidney is called reperfusion (R). Ischemia and reperfusion periods can cause severe kidney damage. Objectives: When we examined the I/R molecular progression, antioxidant molecules such as vitamin A seem promising treatment agents. This study aimed to investigate the effects of vitamin A on renal I/R injury. Material and Methods: In the study, 40 Sprague-Dawley male rats were divided into five groups (n=8): the control group, only I/R, I/R+1000, I/R+3000, and I/R+9000 IU/kg of Vitamin A groups. Vitamin A was administrated to each group for seven days via oral gavage. Blood and kidney tissue samples were collected at the end of the experiment. We took blood samples for Superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), blood urea nitrogen (BUN), and creatinine (Cr) levels, and determined their values. The tissue samples were stained with hematoxylin/eosin to examine the renal changes histopathologically and stereologically under a light microscope. Results: Histopathological changes caused by I/R were decreased with vitamin A administration in a dose-dependent manner (p<0.05). Vitamin A administration decreased MDA levels and increased SOD and CAT activities (p<0.05). The most effective dose among treatment groups was 9000 IU/kg. There was no significant difference between the controls and all other groups regarding BUN and Cr concentrations. Conclusions: Consequently, administration of vitamin A after renal I/R reduced the histological damage and ameliorated the antioxidant state. These results showed that vitamin A could be a promising agent in treating I/R-induced acute kidney injury.

RESUMEN Introducción: La isquemia renal (I) puede desarrollarse debido a la disminución o interrupción del flujo sanguíneo al riñón en algunas condiciones clínicas como shock, sepsis y trasplante renal. El reabastecimiento de sangre al riñón se denomina reperfusión (R). Tanto la isquemia como los períodos de reperfusión pueden causar graves daños renales. Objetivos: Cuando examinamos la progresión molecular I/R, las moléculas antioxidantes como la vitamina A parecen agentes de tratamiento prometedores. El objetivo de este estudio fue investigar los efectos de la vitamina A sobre la lesión renal I/R. Material y Métodos: En el estudio, 40 ratas macho Sprague-Dawley se dividieron en 5 grupos (n=8) como: control, solo I/R, I/R+1000, I/R+3000 e I/R+9000 UI/kg de la Vitamina A. La vitamina A se administró a cada grupo durante 7 días por vía oral forzada. Al final del experimento se recolectaron muestras de sangre y tejido del riñón. A partir de muestras de sangre se determinaron los niveles de superóxido dismutasa (SOD), malondialdehído (MDA), catalasa (CAT), nitrógeno ureico en sangre (BUN) y creatinina (Cr). Las muestras de tejido se tiñeron con hematoxilina/eosina y los cambios en la histología renal se examinaron histopatológicamente y estereológicamente al microscopio de luz. Resultados: Los cambios histopatológicos causados por I/R disminuyeron con la administración de la vitamina A de manera dependiente de la dosis (p<0,05). La administración de la vitamina A disminuyó los niveles de MDA, aumentó las actividades de SOD y CAT (p<0,05). La dosis más eficaz entre los grupos del tratamiento fue de 9000 UI/kg. No hubo una diferencia significativa entre el grupo control y todos los demás grupos con respecto a las concentraciones de BUN y Cr. Conclusiones: Consiguientemente, la administración de la vitamina A, después de I/R renal, redujo el daño histológico y mejoró el estado antioxidante. Estos resultados mostraron que la vitamina A puede ser un agente promisorio en el tratamiento de la lesión renal aguda (LRA) inducida por I/R.

Attainments during the COVID-19: a comparative survey study on ideal anatomy education from the students' perspective.

PURPOSE: Anatomy, one of the cornerstone branches of medical education, is one of the rare areas, where the traditional method remains the most efficient education method despite technological developments. However, the COVID-19 pandemic has made it impossible for the traditional method to continue and has enabled the integration of different distance learning methods into anatomy education. The aim of our study is to perform comparative evaluation of three education methods (traditional, asynchronous online, synchronous online) from the students' perspective. METHODS: In our study, a questionnaire form was sent to Eskisehir Osmangazi University Faculty of Medicine students (n = 168) via Google forms. The students were asked to rank the anatomy education types from the most appropriate to the least appropriate in the proposals. The questionnaire consisted of multiple choice and open-ended questions in addition to 15 proposals questioning demographic information, student autonomy, efficiency, and preference. RESULTS: According to the results obtained, the students stated that the most efficient method (in terms of both theoretical "50%" and practical "55.4%") is the traditional method. In addition, when it comes to preference, students who preferred one of the distance online education types (asynchronous or synchronous) for theoretical anatomy constituted the majority (59.5%). The traditional method was rated as the least appropriate in terms of accessing course resources (42.3%). CONCLUSIONS: According to our study, while face-to-face education is still indispensable for the practical part of the ideal anatomy education, the theoretical part can be carried out remotely by strengthening it with some activities.

A survey study on distance anatomy education: challenges unique to anatomy.

PURPOSE: Traditional anatomy education (TAE) is based on teaching by seeing and touching cadavers/plastic materials that enable three-dimensional thinking, but there was no opportunity like this in distance anatomy education (DAE). Due to the COVID-19 pandemic in 2020, many trainings planned face-to-face were carried out remotely. In this study, our aim is to evaluate students' views on the efficiency of DAE, and to increase the efficiency of DAE in the future. METHODS: The questionnaire used in the study was applied to the first grade students in the Faculty of Medicine, at the Eskisehir Osmangazi University, in 2019-2020. 239 students completed the survey. The questionnaire consisted of the demographic information, that was obtained with voluntary consent, and sections containing suggestions on DAE, and its comparison with distance education of other basic medical science courses. The survey was prepared as a Likert scale (with 1 = totally disagree to 5 = totally agree), on Google forms and sent to the students online. RESULTS: 82.4% of the students marked "totally disagree" or "disagree" for the statement of "DAE is more efficient than TAE". The total percentage of students who marked "totally disagree" or "disagree" for the statement of "I was satisfied with the theoretical education in DAE" was 58.6%, but when it came to practical education the percentage raised to 79.9%. CONCLUSIONS: According to the results the efficiency of DAE, especially in terms of practice lessons, was found to be lower than TAE. To make DAE a powerful alternative to TAE, future studies should aim to develop a new syllabus for DAE.

Effects of metformin on lipopolysaccharide induced inflammation by activating fibroblast growth factor 21.

Lipopolysaccharide (LPS) is a component of the cell wall of Gram-negative bacteria that produces endotoxemia, which may cause septic shock. Metformin (MET) is a widely used hypoglycemic drug that exhibits anti-inflammatory properties. Fibroblast growth factor 21 (FGF21) is an endocrine polypeptide that affects glucose and lipid metabolism, and also possesses anti-inflammatory properties. We investigated the effects of MET and FGF21 on inflammation due to LPS induced endotoxemia in male rats. Animals were divided into five groups: control, LPS, pre-MET LPS, LPS + 1 h MET and LPS + 3 h MET. Serum levels of alanine aminotransferase, aspartate aminotransferase, FGF2, interleukin-10 and tumor necrosis factor alpha were measured. Malondialdehyde, myeloperoxidase and FGF21 levels were measured in liver tissue samples. Histopathology of all groups was assessed using hematoxylin and eosin stained sections. LPS caused severe inflammatory liver damage. MET exhibited a partially protective effect and reduced inflammation significantly. FGF21 is produced in the liver following inflammation and MET may increase its production.

In vivo effects of Viscum album and probiotics against carbon tetrachloride-induced liver injury.

This study tested the possible protective and therapeutic effects of Viscum album extract and probiotics against carbon tetrachloride (CCl4)-induced acute/chronic liver injury. Male Wistar rats were assigned to seven groups: Control, acute CCl4, acute V. album + CCl4, acute V. album + Probiotics + CCl4, chronic CCl4, chronic CCl4 + V. album, and chronic CCl4 + V. album + Probiotics. Acute and chronic liver injuries were induced by 2 mg/kg CCl4 (i.p.) and 1 mg/kg CCl4 (i.p.), respectively. The extract and probiotics were administered daily to related groups. Serum enzyme activities, lipid profile, total protein, albumin, bilirubin, heme oxgenase-1 and 8-hydroxydeoxyguanosine levels were measured. Liver tissue sections stained with Hematoxylin-Eosin. Acute or chronic CCl4-exposure caused to significant changes in concentrations/activities of the measured parameters. The oral administration of extract and probiotics showed protective and therapeutic effects against CCl4-induced liver-injury. The supplementation of intestinal flora by the use of probiotics may enhance the efficacy of orally given therapeutic extracts.

Effects of Conivaptan versus Mannitol on Post-Ischemic Brain Injury and Edema.

OBJECTIVE: The aim of this study was to compare the effects of conivaptan, an arginine vasopressin antagonist, and mannitol, a sugar alcohol, on cerebral ischemia-induced brain injury and edema in rats. MATERIALS AND METHODS: Fifty-eight 8-week-old male Sprague Dawley rats were randomly divided into five groups: control, ischemia-reperfusion (I/R)+saline, I/R+mannitol, I/R+10 mg/ml conivaptan, and I/R+20 mg/ml conivaptan. Cerebral ischemia was induced by common carotid artery occlusion for 30 minutes. Saline, mannitol, or conivaptan were administered intravenously at the onset of reperfusion. Blood and brain tissue samples were taken at the 6th hour of reperfusion. The electrolytes (Na+-K+-Cl-), osmolality, arginine vasopressin, albumin, progranulin (PGRN), neuron-specific enolase (NSE), and myeloperoxidase activity were measured in rat serum samples. Brain frontal/hippocampal sections were stained with hematoxylin-eosin and TUNEL techniques to evaluate histopathological changes. RESULTS: Statistical analyses revealed that conivaptan caused significant changes in the electrolyte, NSE, and PGRN levels and osmolality when compared with mannitol. Conivaptan treatment showed positive effects on serum biochemistry and tissue histology. CONCLUSION: Our findings revealed that conivaptan shows more diuretic activity than mannitol and triggers neither any damages nor edema in the brain tissue. This study may provide beneficial information for the development of treatment strategies for ischemia-related cerebrovascular diseases.