Türkiye’de fizyoloji lisansüstü eğitimine genel bakış

A questionnaire was prepared to determine the current situation, characteristics, main problems and solution proposals of post-graduate physiology education in Turkey. The questionnaire was answered by 40% of the physiology departments with post-graduate programs. The results of the questionnaire demonstrate that 31% of master students and 45% of PhD students have academic positions. Most of the post-graduate physiology students are employed in the "academic staff training program" (62% of master and 59% of PhD students). Post-graduate physiology students were mainly composed of biologists (25%) and medical doctors (21%). All or the majority (81%) of postgraduate students have completed their education within the legal periods. We have observed that post-graduate physiology students do not sufficiently benefit from the national and international student exchange programs, scholarships and do not participate in academic activities. Publication rates of the post-graduate thesis in national and international journals are also below the anticipated level. The general problems faced in providing post-graduate physiology education are insufficiency of available academic positions, scholarships, number of academic staff, inadequate financial support in producing qualified research as well as lack of infrastructure. The results of the questionnaire demonstrate that comprehensive studies with broad participation are necessary in order to improve post-graduate education in our country

The effects of in vivo and ex vivo various degrees of cold exposure on erythrocyte deformability and aggregation

Background: This study aimed to investigate alterations in hemorheology by cold exposure, in vivo and ex vivo, and to determine their relationship to oxidative stress. Material/Methods: Rats were divided into 2 in vivo and ex vivo cold exposure groups. The in vivo group was further divided into control (AR), AC (4°C, 2 hours) and ALTC (4°C, 6 hours) subgroups; and the ex vivo group was divided into control (BR) and BC (4°C, 2 hours) subgroups. Blood samples were used for the determination of erythrocyte deformability, aggregation, and oxidative stress parameters. Results: Erythrocyte deformability and aggregation were not affected by 2-hour ex vivo cold exposure. While 2 hour in vivo cold exposure reduced erythrocyte deformability, it returned to normal after 6 hours, possibly due the compensation by acute neuroendocrine response. Six hours of cold exposure decreased aggregation index, and might be an adaptive mechanism allowing the continuation of circulation. Aggregation of ex vivo groups was lower compared to in vivo groups. Cold exposure at various temperatures did not cause alterations in plasma total oxidant antioxidant status and oxidative stress index (TOS, TAS, OSI) when considered together. Conclusions: Results of this study indicate that the alterations observed in hemorheological parameters due to cold exposure are far from being explained by the oxidative stress parameters determined herein. © Med Sci Monit

Hemorheological responses to progressive resistance exercise training in healthy young males

Background: This study aimed to explore the effects of progressive resistance exercise training (PRET) on hemorheology. Material/Methods: Exercise sessions included 1-3 sets of 8-12 repetitions at 40-60% of 1-repetition maximum (1-RM)for 3 weeks and at 75-80% of 1-RM during weeks 4-12. Red blood cell (RBC) deformability and aggregation were determined by ektacytometry, plasma and whole blood viscosities (WBV) by rotational viscometry. Lactate concentration was evaluated by an analyzer and fibrinogen was evaluated by coagulometry. Plasma total oxidant/antioxidant status was measured by colorimetry. Results: Following an acute increase after exercise on the first day, RBC deformability was elevated during weeks 3 and 4 (p=0.028; p=0.034, respectively). The last exercise protocol applied in week 12 again caused an acute increase in this parameter (p=0.034). RBC aggregation was increased acutely on the first day, but decreased after that throughout the protocol (p<0.05). At weeks 4 and 12 pre-exercise measurements of WBV at standard hematocrit and plasma viscosity were decreased (p=0.05; p=0.041, respectively), while post-exercise values were increased (p=0.005; p=0.04, respectively). Post-exercise WBV at autologous hematocrit measured at week 12 was increased (p=0.01). Lactate was elevated after each exercise session (p<0.05). Fibrinogen was decreased on the third week (p<0.01), while it was increased on the 4th week (p=0.005). Plasma antioxidant status was increased at week 3 (p=0.034) and oxidative stress index was decreased at week 4 (p=0.013) after exercise. Conclusions: The results of this study indicate that PRET may have positive effects on hemorheological parameters. © Med Sci Monit

Vitamin e treatment enhances erythrocyte deformability in aged rats

The harmful effects of aging on blood rheology have been well known. These effects in the aging have been found to be associated with an increase in oxidative stress. The aim of this study was to seek whether treatment of vitamin E as a potent antioxidant could improve the age-related haemorheological abnormalities. For this purpose, male Wistar rats at the age of 3 and 24 months were used. The following parameters were evaluated: red blood cell (RBC) deformability, aggregation, plasma viscosity, vitamin E level, total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI), and the following results were obtained. First, aging was associated with a decrease in RBC deformability and increase in RBC aggregation and plasma viscosity. Second, compared with the young group, while plasma TOS levels and OSI were found to be significantly increased in aged rats, there was no significant change in their plasma TAS level. Third, vitamin E administration produced significant improvement in RBC deformability and decrement in TOS and OSI values in aged rats with respect to young and aged control groups. We did not find any significant effect of vitamin E treatment on RBC aggregation in both young and aged rats and finally, we found a significantly lower plasma vitamin E level in aged rats than in young rats. In conclusion, these findings suggest that blood rheology impairs with age and vitamin E has ameliorating effects on age-induced haemorheological abnormalities especially in RBC deformability, probably by reducing the increased oxidative stress in old age

Impaired Hemorheology in Exacerbations of COPD

Background. Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation. Cardiovascular-related comorbidities are established to contribute to morbidity and mortality especially during exacerbations. The aim of the current study was to determine alterations in hemorheology (erythrocyte aggregation, deformability) in newly diagnosed COPD patients and their response to medical treatment and to compare with values of COPD patients with exacerbations. Materials and Methods. The study comprised 13 COPD patients, 12 controls, and 16 COPD patients with exacerbations. The severity of COPD was determined according to Global Initiative for Chronic Obstructive Lung Disease guidelines. Red blood cell (RBC) deformability and aggregation were measured by an ektacytometer. Results. RBC deformability of COPD patients with exacerbations was decreased compared to the other groups. Erythrocyte aggregation and plasma fibrinogen of COPD patients determined during exacerbations were higher than control. Conclusion. Decreased RBC deformability and increased aggregation associated with exacerbations of COPD may serve as unfavorable mechanisms to worsen oxygenation and thus clinical symptoms of the patient. Treatment modalities that modify rheological parameters might be beneficial. © 2017 Erhan Ugurlu et al

Increased deformability of red blood cells is associated with a deletion polymorphism of the angiotensin-converting enzyme gene

Angiotensin-converting enzyme (ACE) plays important roles in the renin-angiotensin system. ACE converts angiotensin I to angiotensin II and also inactivates bradykinin, thereby modulating the vascular tone. A polymorphism of the ACE gene, located on chromosome 17, has been found in intron 16, and is characterized by the presence (insertion [I]) or absence (deletion [D]) of a 287-base-pair Alu repeat. Individuals with the D allele of the ACE gene have higher ACE levels and are at higher risk of cardiovascular events. We aimed to investigate the possible relationship between the I/D polymorphism of the ACE gene and hemorheological parameters, including red blood cell (RBC) deformability. The study was performed on 28 healthy young volunteers (13 women and 15 men, mean age 24 ± 2). The prevalence of the I and D alleles was 30.4% and 69.6%, respectively. The I/I genotype (II) was found in 21.4%, I/D genotype (ID) in 17.9%, and D/D genotype (DD) in 60.7% of the subjects tested. No significant relationship between ACE I/D polymorphism and RBC aggregation or whole blood and plasma viscosity was observed. In contrast, RBC deformability was significantly increased in the subjects with the DD genotype compared with the II (p < 0.05) or the ID (p < 0.01) genotype, and in the subjects with the D allele compared with the I allele (p < 0.01). We suggest that RBC deformability of individuals with the D allele, who have higher risk for cardiovascular pathologies, may have been increased by a compensatory mechanism. © 2006 Tohoku University Medical Press

Effect of sulfite treatment on erythrocyte deformability in young and aged rats

It is known that aging is associated with marked effects on integrity and function of cell membrane. These effects may also be exacerbated by exogenous chemicals, e.g. sulfite. Thus, the aim of this paper is to examine the influence of sulfite on hemorheological and related hematological parameters in rats of various ages. In this study, male Wistar rats at the age of 3 and 18 months were used and the following parameters were evaluated: Mean Cell Volume (MCV), Mean Corpuscular Hemoglobin Concentration (MCHC), Red blood Cell (RBC) deformability and aggregation. The results show that aging is associated with a decrease in RBC deformability and MCHC, an increase in MCV. Sulfite administration significantly increased RBC deformability in both young and aged rats. Although MCHC was decreased in young rats, it was increased in aged rats in response to sulfite exposure. Additionally, sulfite induced a decrement in MCV of aged rats. Neither aging nor sulfite treatment caused significant alterations in RBC aggregation parameters in all experimental groups. In conclusion, these findings suggest that RBC deformability impairs with age and sulfite has ameliorating effects on RBC deformability in both young and aged rats. Copyright © Informa UK Ltd

Effect of sulfite on red blood cell deformability ex vivo and in normal and sulfite oxidase-deficient rats in vivo

The effect of sulfite, a widely used food additive, on red blood cell deformability ex vivo and in vivo was investigated. Ex vivo experiments were conducted in human blood exposed to sulfite (5, 10 and 20 mM). In vivo experiments were carried out in sulfite oxidase-competent (SOXC) and sulfite oxidase-deficient (SOXD) rats. In the in vivo experiments, sulfite was administered in the form of sodium metabisulfite (Na2S 2O5, 25 mg/kg/day) via drinking water. Vitamin E dissolved in olive oil at a dose of 50 mg/kg was administered by gastric gavages. Red blood cell (RBC) deformability was determined at various fluid shear stresses using an ektacytometer. Ex vivo sulfite exposure to RBC did not affect RBC deformability. In the in vivo experiments, although RBC deformability was not affected by sulfite treatment in SOXD rats, it was found to be significantly increased in SOXC rats. Vitamin E treatment in combination with sulfite caused impairment in RBC deformability in both SOXC and SOXD rats. We suggest that sulfite needs to be oxidized in order to improve RBC deformability. © Springer-Verlag 2005