Following-up changes in red blood cell deformability and membrane stability in the presence of PTFE graft implanted into the femoral artery in a canine model

Toth, Csaba,Kiss, Ferenc,Klarik, Zoltan,Gergely, Eszter,Toth, Eniko,Vanyolos, Katalin Peto Erzsebet,Miko, Iren,Nemeth, Norbert 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.2

It is known that a moderate mechanical stress can even improve the red blood cells' (RBC) micro-rheological characteristics, however, a more significant stress causes deterioration in the deformability. In this study, we aimed to investigate the effect of the presence of artificial graft on the RBC deformability and membrane stability in beagles. In the Control group only anesthesia was induced and in the postoperative (p.o.) period blood samplings were carried out. In the Grafted group under general anesthesia, the left femoral artery was isolated, from which a 3.5 cm segment was resected and a PTFE graft (O.D.: 3 mm) of equal in length was implanted into the gap. On the $1^{st}$, $3^{rd}$, $5^{th}$, $7^{th}$ and 14th p.o. days blood was collected the cephalic veins and RBC deformability was determined ektacytometry (LoRRca MaxSis Osmoscan). Membrane stability test consisted of two deformability measurements before and after the cells were being exposed to mechanical stress (60 or 100 Pa for 300 seconds). Compared to the Control group and the baseline values the red blood cell deformability showed significant deterioration on the $3^{rd}$, $5^{th}$ and mainly on the $7^{th}$ postoperative day after the graft implantation. The membrane stability of erythrocyte revealed marked inter-group difference on the $3^{rd}$, $5^{th}$ and $7^{th}$ day: in the Grafted group the deformability decreased and during the membrane stability test smaller difference was observed between the states before and after shearing. We concluded that the presence of a PTFE graft in the femoral artery may cause changes in RBC deformability in the first p.o. week. RBC membrane stability investigation shows a lower elongation index profile for the grafted group and a narrowed alteration in the deformability curves due to mechanical stress.

Hemorheological parameters in coronary artery disease detected by multi-slice CT

Toth, Andras,Szukits, Sandor,Varady, Edit,Sandor, Barbara,Rabai, Miklos,Papp, Judit,Juricskay, Istvan,Kesmarky, Gabor,Toth, Kalman,Sumegi, Balazs,Battyani, Istvan 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.2

Epidemiological studies have confirmed that hemorheological parameters are primary risk factors in CAD; and their alterations in CAD have been described. We aimed to investigate both macro- and microrheological properties of blood in patients with CAD. The data of 121 patients (mean age: $58.8{\pm}9.6$ years) undergoing coronary CT were analyzed. Blood samples were obtained right before CT examinations. Hematocrit (Hct), plasma (PV) and apparent whole blood viscosity (WBV), red blood cell (RBC) aggregation and RBC deformability were measured. Patients were classified into four groups according to their coronary vessel state: Negative group (n = 32, mean age: $56.8{\pm}11.1$ years) without any coronary stenosis or atherosclerotic lesion and zero calcium-score, Non-significant group (n = 27, mean age: $59.2{\pm}7.5$ years) below 40% area stenosis, Single-vessel group (n = 32, mean age: $58.8{\pm}8.5$ years) over 40% area stenosis or history of PCI or CABG on one coronary vessel, Multi-vessel group (n = 30, mean age: $62.1{\pm}8.4$ years) with over 40% area stenosis or history of PCI or CABG on multiple coronary vessels. Hct was significantly (p < 0.05) higher in all CAD (Non-significant, Single-vessel, Multi-vessel) groups compared to the Negative group. WBV was significantly (p<0.05) higher in the Multi-vessel group compared to the Negative group. No significant ($p{\geq}0.05$) differences were observed in PV. RBC aggregation was significantly (p < 0.05) increased in the Multi-vessel group compared to the Negative group. RBC deformability showed a decreasing tendency with the increasing number of atherosclerotic vessels. Our results indicate that hemorheological variables are deteriorated in patients with CAD established by coronary CT, which is more pronounced in severe coronary disease.

Hemorheological parameters in coronary artery disease detected by multi-slice CT

Andras Toth,Sandor Szukits,Edit Varady,Barbara Sandor,Miklos Rabai,Judit Papp,Istvan Juricskay,Gabor Kesmarky,Kalman Toth,Balazs Sumegi,Istvan Battyani 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.2

Epidemiological studies have confirmed that hemorheological parameters are primary risk factors in CAD;and their alterations in CAD have been described. We aimed to investigate both macro- and microrheologicalproperties of blood in patients with CAD. The data of 121 patients (mean age: 58.8 ± 9.6 years) undergoingcoronary CT were analyzed. Blood samples were obtained right before CT examinations. Hematocrit (Hct),plasma (PV) and apparent whole blood viscosity (WBV), red blood cell (RBC) aggregation and RBC deformabilitywere measured. Patients were classified into four groups according to their coronary vessel state: Negativegroup (n = 32, mean age: 56.8 ± 11.1 years) without any coronary stenosis or atherosclerotic lesion andzero calcium-score, Non-significant group (n = 27, mean age: 59.2 ± 7.5 years) below 40% area stenosis, Single-vessel group (n = 32, mean age: 58.8 ± 8.5 years) over 40% area stenosis or history of PCI or CABG onone coronary vessel, Multi-vessel group (n = 30, mean age: 62.1 ± 8.4 years) with over 40% area stenosis orhistory of PCI or CABG on multiple coronary vessels. Hct was significantly (p < 0.05) higher in all CAD(Non-significant, Single-vessel, Multi-vessel) groups compared to the Negative group. WBV was significantly(p<0.05) higher in the Multi-vessel group compared to the Negative group. No significant (p ≥ 0.05) differenceswere observed in PV. RBC aggregation was significantly (p < 0.05) increased in the Multi-vesselgroup compared to the Negative group. RBC deformability showed a decreasing tendency with the increasingnumber of atherosclerotic vessels. Our results indicate that hemorheological variables are deteriorated inpatients with CAD established by coronary CT, which is more pronounced in severe coronary disease.

Following-up changes in red blood cell deformability and membrane stability in the presence of PTFE graft implanted into the femoral artery in a canine model

Csaba Toth,Ferenc Kiss,Zoltan Klarik,Eszter Gergely,Eniko Toth,Katalin Peto,Erzsebet Vanyolos,Iren Miko,Norbert Nemeth 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.2

It is known that a moderate mechanical stress can even improve the red blood cells’ (RBC) micro-rheologicalcharacteristics, however, a more significant stress causes deterioration in the deformability. In thisstudy, we aimed to investigate the effect of the presence of artificial graft on the RBC deformability andmembrane stability in beagles. In the Control group only anesthesia was induced and in the postoperative(p.o.) period blood samplings were carried out. In the Grafted group under general anesthesia, the leftfemoral artery was isolated, from which a 3.5 cm segment was resected and a PTFE graft (O.D.: 3 mm)of equal in length was implanted into the gap. On the 1st, 3rd, 5th, 7th and 14th p.o. days blood was collectedthe cephalic veins and RBC deformability was determined ektacytometry (LoRRca MaxSis Osmoscan). Membrane stability test consisted of two deformability measurements before and after the cells werebeing exposed to mechanical stress (60 or 100 Pa for 300 seconds). Compared to the Control group andthe baseline values the red blood cell deformability showed significant deterioration on the 3rd, 5th andmainly on the 7th postoperative day after the graft implantation. The membrane stability of erythrocyterevealed marked inter-group difference on the 3rd, 5th and 7th day: in the Grafted group the deformabilitydecreased and during the membrane stability test smaller difference was observed between the statesbefore and after shearing. We concluded that the presence of a PTFE graft in the femoral artery maycause changes in RBC deformability in the first p.o. week. RBC membrane stability investigation showsa lower elongation index profile for the grafted group and a narrowed alteration in the deformabilitycurves due to mechanical stress.

Aspirin resistance as cardiovascular risk after kidney transplantation

Barbara Sandor,Adam Varga,Miklos Rabai,Andras Toth,Judit Papp,Kalman Toth,Peter Szakaly 한국유변학회 2014 Korea-Australia rheology journal Vol.26 No.2

International surveys have shown that the leading cause of death after kidney transplantation has cardiovascularorigin with a prevalence of 35-40%. As a preventive strategy these patients receive aspirin (ASA)therapy, even though their rate of aspirin resistance is still unknown. In our study, platelet aggregation measurementswere performed between 2009 and 2012 investigating the laboratory effect of low-dose aspirin(100 mg) treatment using a CARAT TX4 optical aggregometer. ASA therapy was considered clinically effectivein case of low (i.e., below 40%) epinephrine-induced (10 μM) platelet aggregation index. Rate of aspirinresistance, morbidity and mortality data of kidney transplanted patients (n = 255, mean age: 49 ± 12 years)were compared to a patient population with cardio- and cerebrovascular diseases (n = 346, mean age: 52.6 ± 11years). Rate of aspirin resistance was significantly higher in the renal transplantation group (RT) compared tothe positive control group (PC) (35.9% vs. 25.6%, p < 0.002). Morbidity analysis demonstrated significantlyhigher incidence of myocardial infarction, hypertension and diabetes mellitus in the RT group (p < 0.05). Thesubgroup analysis revealed significantly higher incidence of infarction and stroke in the ASA resistant RTgroup compared to the RT patients without ASA resistance (p < 0.05). Furthermore, the incidence of myocardialinfarction and hypertension was significantly higher in the non-resistant RT group than in the groupof PC patients without ASA resistance (p < 0.05). These results may suggest that the elevated rate of aspirinresistance contributes to the high cardiovascular mortality after kidney transplantation.

Natural and Human-induced Salimization of Soils

Toth, T. 한국토양비료학회 2009 한국토양비료학회 학술발표회 초록집 Vol.2009 No.10

곰팡이독소 다중분석법

Toth, Danrey 한국식품위생안전성학회 2012 Safe Food Vol.7 No.4

STAT2 Knockout Syrian Hamsters Support Enhanced Replication and Pathogenicity of Human Adenovirus, Revealing an Important Role of Type I Interferon Response in Viral Control

Toth, Karoly,Lee, Sang R.,Ying, Baoling,Spencer, Jacqueline F.,Tollefson, Ann E.,Sagartz, John E.,Kong, Il-Keun,Wang, Zhongde,Wold, William S. M. Public Library of Science 2015 PLoS pathogens Vol.11 No.8

<▼1><P>Human adenoviruses have been studied extensively in cell culture and have been a model for studies in molecular, cellular, and medical biology. However, much less is known about adenovirus replication and pathogenesis <I>in vivo</I> in a permissive host because of the lack of an adequate animal model. Presently, the most frequently used permissive immunocompetent animal model for human adenovirus infection is the Syrian hamster. Species C human adenoviruses replicate in these animals and cause pathology that is similar to that seen with humans. Here, we report findings with a new Syrian hamster strain in which the STAT2 gene was functionally knocked out by site-specific gene targeting. Adenovirus-infected STAT2 knockout hamsters demonstrated an accentuated pathology compared to the wild-type control animals, and the virus load in the organs of STAT2 knockout animals was 100- to 1000-fold higher than that in wild-type hamsters. Notably, the adaptive immune response to adenovirus is not adversely affected in STAT2 knockout hamsters, and surviving hamsters cleared the infection by 7 to 10 days post challenge. We show that the Type I interferon pathway is disrupted in these hamsters, revealing the critical role of interferon-stimulated genes in controlling adenovirus infection. This is the first study to report findings with a genetically modified Syrian hamster infected with a virus. Further, this is the first study to show that the Type I interferon pathway plays a role in inhibiting human adenovirus replication in a permissive animal model. Besides providing an insight into adenovirus infection in humans, our results are also interesting from the perspective of the animal model: STAT2 knockout Syrian hamster may also be an important animal model for studying other viral infections, including Ebola-, hanta-, and dengue viruses, where Type I interferon-mediated innate immunity prevents wild type hamsters from being effectively infected to be used as animal models.</P></▼1><▼2><P><B>Author Summary</B></P><P>The biology of human adenoviruses has been studied extensively; however, much less is known about the replication and pathogenesis of the virus in a permissive host. Our laboratory pioneered the use of Syrian hamsters to study the pathogenesis of human adenoviruses. Syrian hamsters are permissive for species C human adenoviruses, which replicate in these animals and cause illness akin to that in humans. Hereby, we report findings with a new Syrian hamster strain (STAT2 KO hamsters), in which the Type I interferon pathway, an important part of the innate immune response to virus infection, is disrupted. This is the first genetically modified Syrian hamster strain ever reported. We show that these animals are very sensitive to infection with type 5 human adenovirus (Ad5). Ad5 replicates to 100- to 1000-fold higher titers in STAT2 KO hamsters than in wild-type ones, and this increased infection causes enhanced pathology. However, the adaptive immune response to the virus infection seems to be intact with the STAT2 KO hamsters, and surviving animals clear the virus effectively. The data reported here may be of interest to researchers focusing on adenoviruses, and also to those who utilize the Syrian hamster as their animal model for other purposes.</P></▼2>

COUNTING SUBRINGS OF THE RING ℤ_m × ℤ_n

Toth, Laszlo Korean Mathematical Society 2019 대한수학회지 Vol.56 No.6

Let $m,n{\in}{\mathbb{N}}$. We represent the additive subgroups of the ring ${\mathbb{Z}}_m{\times}{\mathbb{Z}}_n$, which are also (unital) subrings, and deduce explicit formulas for $N^{(s)}(m,n)$ and $N^{(us)}(m,n)$, denoting the number of subrings of the ring ${\mathbb{Z}}_m{\times}{\mathbb{Z}}_n$ and its unital subrings, respectively. We show that the functions $(m,n){\mapsto}N^{u,s}(m,n)$ and $(m,n){\mapsto}N^{(us)}(m,n)$ are multiplicative, viewed as functions of two variables, and their Dirichlet series can be expressed in terms of the Riemann zeta function. We also establish an asymptotic formula for the sum $\sum_{m,n{\leq}x}N^{(s)}(m,n)$, the error term of which is closely related to the Dirichlet divisor problem.

기획특집 : 곰팡이독소 다중분석법

( Danrey Toth ) 한국식품위생안전성학회 2012 Safe Food Vol.7 No.4