Mustafa Tugrul Goktas

Relation of the Allelic Variants of Multidrug Resistance Gene to Agranulocytosis Associated With Clozapine.

Abstract Clozapine use is associated with leukopenia and more rarely agranulocytosis, which may be lethal. The drug and its metabolites are proposed to interact with the multidrug resistance transporter (ABCB1/MDR1) gene product, P-glycoprotein (P-gp). Among various P-glycoprotein genetic polymorphisms, nucleotide changes in exons 26 (C3435T), 21 (G2677T), and 12 (C1236T) have been implicated for changes in pharmacokinetics and pharmacodynamics of many substrate drugs. In this study, we aimed to investigate the association between these specific ABCB1 polymorphisms and clozapine-associated agranulocytosis (CAA). Ten patients with a history of CAA and 91 control patients without a history of CAA, despite 10 years of continuous clozapine use, were included. Patient recruitment and blood sample collection were conducted at the Hacettepe University Faculty of Medicine, Department of Psychiatry, in collaboration with the members of the Schizophrenia and Other Psychotic Disorders Section of the Psychiatric Association of Turkey, working in various psychiatry clinics. After DNA extraction from peripheral blood lymphocytes, genotyping was performed using polymerase chain reaction and endonuclease digestion. Patients with CAA had shorter duration of clozapine use but did not show any significant difference in other clinical, sociodemographic characteristics and in genotypic or allelic distributions of ABCB1 variants and haplotypes compared with control patients. Among the 10 patients with CAA, none carried the ABCB1 all-variant haplotype (TT-TT-TT), whereas the frequency of this haplotype was approximately 12% among the controls. Larger sample size studies and thorough genetic analyses may reveal both genetic risk and protective factors for this serious adverse event.

Celecoxib administration reduced mortality, mesenteric hypoperfusion, aortic dysfunction and multiple organ injury in septic rats.

BACKGROUND The cyclooxygenase (COX)-2 overexpression is associated with vascular injury and multiple organ failure in sepsis. However, constitutive COX-1 and basal COX-2 expressions have physiological effects. We aimed to investigate the effects of partial and selective COX-2 inhibition without affecting constitutive COX-1 and basal COX-2 activities by celecoxib on mesenteric artery blood flow (MABF), vascular reactivity, oxidative and inflammatory injuries, and survival in septic rats accomplished by cecal ligation and puncture (CLP). METHODS Wistar rats were allocated into Sham, CLP, Sham+celecoxib, CLP+celecoxib subgroups. 2h after Sham and CLP operations, celecoxib (0.5mg/kg) or vehicle (saline; 1mL/kg) was administered orally to rats. 18h after drug administrations, MABF and responses of isolated aortic rings to phenylephrine were measured. Tissue samples were obtained for biochemical and histopathological examinations. Furthermore, survival rate was monitored throughout 96h. RESULTS Celecoxib ameliorated mesenteric hypoperfusion and partially improved aortic dysfunction induced by CLP. Survival rate was%0 at 49th h in CLP group, but in CLP+celecoxib group it was 42.8% at the end of 96h. Serum AST, ALT, LDH, BUN, Cr and inflammatory cytokine (tumor necrosis factor-alpha, interleukin-1 beta and interleukin-6) levels were increased in CLP group that were prevented by celecoxib. The decreases in liver and spleen glutathione levels and the increases in liver, lung, spleen and kidney malondialdehyde levels in CLP group were blocked by celecoxib. The histopathological protective effects of celecoxib on organ injury due to CLP were also observed. CONCLUSIONS Celecoxib has protective effects on sepsis due to its preservative effects on mesenteric perfusion, aortic function and its anti-inflammatory and antioxidative effects.

Thymoquinone protects against the sepsis induced mortality, mesenteric hypoperfusion, aortic dysfunction and multiple organ damage in rats

BACKGROUND Thymoquinone (TQ) is a potent cytoprotective, antioxidant and anti-inflammatory agent. We aimed to investigate the possible protective effects of TQ on survival, mesenteric artery blood flow (MABF), vascular reactivity, oxidative and inflammatory injuries in a murine sepsis model induced by cecal ligation and puncture (CLP). METHODS Wistar rats were divided into the following four groups: Sham, CLP, Sham+TQ and CLP+TQ. TQ (1mg/kg/day) or vehicle (dimethyl sulfoxide, 1mL/kg/day) was intraperitoneally injected for 3 days. At 4th day Sham or CLP operation was applied. 20h after the operations, MABF and contractile responses of isolated aortic rings to phenylephrine were measured. Tissue samples were obtained for histopathological and biochemical examinations. Also, survival rates were recorded throughout 96h. RESULTS TQ ameliorated mesenteric hypoperfusion and partially attenuated aortic dysfunction induced by CLP. Survival rate was %0 at 42nd h in CLP group, but in CLP+TQ group it was 33.4% at the end of 96h. Serum levels of AST, ALT, LDH, BUN, Cr and inflammatory cytokines (tumor necrosis factor-α, interleukin-1 β and interleukin-6) increased in CLP group that were prevented by TQ. The decreases in liver, spleen and kidney glutathione levels and the increases in liver, lung, kidney and spleen malondialdehyde levels induced by CLP were inhibited by TQ. The histopathological protective effects of TQ on multiple organ damage due to CLP were also observed. CONCLUSION TQ has ameliorative effects on sepsis due to its protective effects on mesenteric perfusion, contractile function of aorta and its anti-inflammatory and antioxidative effects.

Infliximab alleviates the mortality, mesenteric hypoperfusion, aortic dysfunction, and multiple organ damage in septic rats

Tumor necrosis factor-alpha (TNF-α) is a pivotal mediator that triggers inflammatory process, oxidative stress, and multiple organ injury in sepsis. We investigated the effects of infliximab on survival, mesenteric artery blood flow (MBF), vascular reactivity, and oxidative and inflammatory injuries in cecal ligation and puncture (CLP)-induced sepsis. Wistar rats were divided into Sham, CLP, Sham+infliximab, and CLP+infliximab subgroups. Twenty-four hours before the operations, rats were injected intraperitoneally with infliximab (7 mg/kg) or vehicle (saline; 1 mL/kg). Twenty hours after the operations, MBF and phenylephrine responses of isolated aortic rings were measured. Tissue damages were examined biochemically and histopathologically. Furthermore, survival rates were monitored throughout 96 h. Infliximab improved survival, mesenteric perfusion, and aortic function after CLP. Increases of serum AST, ALT, LDH, BUN, Cr, and inflammatory cytokines (tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6) induced by CLP were blocked by infliximab. Infliximab prevented malondialdehyde elevations in septic liver, lung, spleen, and kidney tissues, as well as glutathione reductions in septic liver, spleen, and kidney tissues. Protective effects of infliximab on multiple organ damage were also observed histopathologically. Infliximab showed protective effects in sepsis due to its improvement effects on mesenteric perfusion, aortic function, and its anti-inflammatory and antioxidative effects.

Coenzyme Q10 improves the survival, mesenteric perfusion, organs and vessel functions in septic rats

BACKGROUND Coenzyme Q10 (CoQ10) is a naturally occurring, lipid-soluble antioxidant and an essential electron carrier in the mitochondrial respiratory chain. In sepsis, CoQ10 deficiency induced by mitochondrial failure can lead to hypoxia, hypoperfusion, oxidative organ damage and finally death. We aimed to investigate the effects of CoQ10 on survival, mesenteric artery blood flow (MABF), vascular reactivity, oxidative and inflammatory injuries in cecal ligation and puncture (CLP)-induced sepsis. METHODS Wistar rats were divided into Sham, CLP, Sham+CoQ10, CLP+CoQ10 subgroups. CoQ10 (10mg/kg/day) or vehicle (olive oil; 1mL/kg/day) was intraperitoneally injected for 15days. At 16th day, Sham or CLP operation was performed. 20h after the operations, MABF and phenylephrine responses of isolated aortic rings were measured. Tissue samples were obtained for histopathological and biochemical evaluations. Furthermore, survival rates were monitored throughout 96h. RESULTS CoQ10 prevented mesenteric hypoperfusion and aortic dysfunction induced by CLP. Survival rate was %0 at 46th h in CLP group, but in CLP+CoQ10 group it was 37.5% at the end of 96h. CLP-induced elevations of serum AST, ALT, LDH, BUN, Cr and inflammatory cytokine (tumor necrosis factor-alpha, interleukin-1 beta and interleukin-6) levels were blocked by CoQ10. CoQ10 restored the increased liver, lung, spleen and kidney malondialdehyde levels and as well as reduced liver and spleen glutathione levels. The protective effects of CoQ10 on multiple organ damage were also observed histopathologically. CONCLUSIONS CoQ10 showed protective effects in sepsis due to its preservative effects on mesenteric perfusion, aortic function and also its anti-inflammatory and antioxidative effects.

Effects of Genetic Polymorphisms of Cytochrome P450 Enzymes and MDR1 Transporter on Pantoprazole Metabolism and Helicobacter pylori Eradication.

Pantoprazole is a proton pump inhibitor that is commonly used in the treatment of peptic ulcer disease (PUD) and metabolized by cytochrome P450 (CYP) enzymes CYP2C19 and CYP3A4. Pantoprazole is a substrate for multi‐drug resistance protein 1 (MDR1). Single nucleotide polymorphisms (SNPs) in CYP2C19, CYP3A4 and MDR1 affect enzyme activity or gene expression of proteins and may alter plasma pantoprazole concentrations and treatment success in PUD. In this study, we aimed to investigate the association between genetic polymorphisms in CYP2C19, CYP3A4 and MDR1 and pharmacokinetics of pantoprazole and therapeutic outcome in patients with either Helicobacter pylori‐associated [H.P.(+)]‐PUD or [H.P.(+)]‐gastritis. The plasma pantoprazole concentrations were determined by using an HPLC method at the third hour after a 40‐mg tablet of pantoprazole administration in 194 newly diagnosed patients with either [H.P.(+)]‐PUD or [H.P.(+)]‐gastritis. Genotyping was performed by using PCR‐RFLP and DNA sequencing. Among patients appearing for follow‐up examination (n = 105), the eradication rate for H. pylori was 82.8% (n = 87). The median pantoprazole plasma concentrations in poor metabolizers (PM), rapid metabolizers (RM) and ultrarapid metabolizers (URM) were 2.07, 1.69 and 1.28 μg/ml, respectively (p = 0.04). CYP3A4*1G and *22 polymorphisms did not affect plasma pantoprazole concentrations and H. pylori eradication rate. The MDR1 genetic polymorphisms did not affect plasma pantoprazole concentrations. MDR1 3435CC‐2677GG‐1236CC haplotype carriers had lower H. pylori eradication rate (60%) than the remaining subjects (84.9%) while the difference was not statistically significant (p = 0.07). In conclusion, while CYP2C19 genetic polymorphisms significantly affected plasma pantoprazole concentrations, polymorphisms of CYP2C19, CYP3A4 and MDR1 did not affect H. pylori eradication rates.

Decreased Activity and Genetic Polymorphisms of CYP2C19 in Behçet's Disease.

Behçets disease (BD) is a systemic autoimmune disorder. Cytochrome P450 enzymes (CYPs) are responsible for various drug metabolism reactions as well as those of endogenous substances which may be associated with autoimmune disease susceptibility. Recently, we reported that in patients with BD, CYP2C9 seems to be down‐regulated due to inflammation. In the same Turkish patients with BD, we investigated whether also CYP2C19 activity is decreased. Lansoprazole (30 mg) was given as a probe drug to evaluate CYP2C19 activity in 59 patients with BD and 27 healthy control volunteers. An HPLC method was used to determine plasma lansoprazole and its metabolite, 5‐hydroxy lansoprazole, concentrations. The genotyping for CYP2C19 *2, *3 and *17 polymorphisms was made using PCR‐RFLP. The median lansoprazole/5‐hydroxy lansoprazole metabolic ratio (MR) in patients with BD was 2.6‐fold higher as compared to the healthy control group (p = 0.001, 22.6 (1.3–26) and 8.8 (0.5–140) as median and range, respectively). The CYP2C19*17*17 genotype frequency was found to be significantly less in the BD group as compared to the healthy controls (1.7% versus 14.8% in controls, p = 0.01). Additionally, colchicine treatment did not affect the CYP2C19 enzyme activity in six patients (p = 0.43). In conclusion, the patients with BD had lower CYP2C19 enzyme activity and lower frequency of the CYP2C19*17 allele as compared to those of the healthy controls. Further studies are warranted on the mechanisms underlying this relation. This study should also be applied to other autoimmune diseases similarly characterized by local or systemic inflammation.

Investigation of 1377C/T polymorphism of the Toll-like receptor 3 among patients with chronic hepatitis B

The immunopathogenesis of chronic hepatitis B (CHB) has not been clarified yet. Toll-like receptors (TLR) are a receptor family that initiates immunity with exogenous-endogenous ligands and plays a role in the pathogenesis of infections. In this study, we aimed to investigate the frequency of TLR 3 1377C/T (rs3775290) polymorphism and its role in patients with CHB. We included 50 healthy individuals as control group and 73 active and 43 inactive hepatitis B patients. All DNA samples were isolated from blood samples. For the detection of TLR 3 1377C/T single-nucleotide polymorphism, restriction fragment length polymorphism was used. A statistically significant difference was determined in Hepatitis B virus (HBV) DNA levels of CHB patients with the CC, CT, and TT genotypes (p = 0.013). The highest levels of HBV DNA were detected in individuals with TT genotypes. Additionally, the frequency of CC genotype was higher in the active CHB patients compared with that of the inactive CHB patients (p = 0.044). No statistically significant difference in TLR 3 1377C/T polymorphism was detected between healthy controls and the hepatitis B patients (p = 0.342). In conclusion, HBV DNA level was higher in the individuals with TT genotype, and CC genotype was more frequent in the active CHB patients. These results suggest a possible association between CHB and TLR 3 gene (1377C/T) polymorphism.

Oral Candida carriage and prevalence of Candida species among Maras powder users and non-users

INTRODUCTION The aim of this study was to investigate Candida carriage and species in Maras powder users and non-users. MATERIAL AND METHODS This study included 100 volunteering men in 12 cafés in the city of Kahramanmaras, Turkey. A questionnaire composed of questions about socio-demographic features and Maras powder use was filled in by the participants. Culture specimens were obtained from bilateral buccal mucosa and dorsum of the tongue with a sterile cotton-tipped swap. The specimens were inoculated in Sabouraud Dextrose Agar (SDA). RESULTS The mean age of the participants was 48.0 ± 12.5 years (min = 20, max = 70). Fifty-four percent of the Maras powder users and 22% of the non-users were Candida carriers. The difference between the groups was significant (P = 0.001). The most frequently isolated species was Candida albicans at a rate of 44% in the Maras powder users and at a rate of 18% in the non-users. Other frequent species were Candida glabrata at a rate of 6% in the Maras powder users and 2% in the control group and Candida tropicalis at a rate of 4% in the Maras powder users and 2% in the nonusers. CONCLUSION We found that a significantly high rate of the Maras powder users was Candida carriers. It should be kept in mind that opportunistic infections may be caused by Candida species in Maras powder users especially with immunosuppressive conditions since Candida species are likely to lead to such infections in cases of immunosuppressive diseases.