Examination of the effects of thiamine and thiamine pyrophosphate on Doxorubicin-induced experimental cardiotoxicity.

BACKGROUND AND PURPOSE: To investigate the effect of thiamine and thiamine pyrophosphate on doxorubicin-induced cardiotoxicity biochemically and histopathologically and to examine whether doxorubicin cardiotoxicity is related to the conversion of thiamine into thiamine pyrophosphate and inhibition of thiamine pyrophosphokinase (TPK) enzyme. EXPERIMENTAL APPROACH: A total of 48 Albino Wistar male rats were used. Rats were divided into groups as thiamine + doxorubicin (TIA + DOX), thiamine pyrophosphate + doxorubicin (TPP + DOX), DOX, and healthy (HEA) groups. One hour after the administration of thiamine and TPP in 25 mg/kg doses, 5 mg/kg doxorubicin were injected to all groups except HEA group during 7 days. Then, the samples were collected for biochemical (glutathione [GSH], malondialdehyde [MDA], DNA damage, creatine kinase (CK), CK-MB, and troponine I [TP-I]), molecular (TPK), and histopathological examinations. KEY RESULTS: Oxidant parameters (MDA and DNA damage) decreased and antioxidant parameter (GSH) increased in TPP + DOX group. In addition, levels of CK, CK-MB, and TP-I were low in the TPP + DOX group and high in the TIA + DOX and DOX groups. Cardiac tissue was protected in TPP + DOX group, and no protective effect was observed in TIA + DOX and DOX groups. Messenger RNA expression of TPK was decreased in DOX and TIA + DOX groups. CONCLUSION AND IMPLICATIONS: The cardiotoxic effect of doxorubicin originated from the inhibition of TPK enzyme resulting in insufficient production of thiamine pyrophosphate.

Correlation between the serum values of soluble intercellular adhesion molecule-1 and total sialic acid levels in patients with breast cancer.

BACKGROUND: In this study, we aimed to investigate serum total sialic acid (TSA) and soluble intracellular adhesion molecule-1 (sICAM-1) levels in breast cancer patients to find a correlation with the cancer stage. METHODS: The parameters from sera of 61 patients with breast cancer were measured. The concentrations of serum sICAM-1 and TSA were measured in serum samples from 61 patients with breast cancer and 25 healthy control subjects using enzyme-linked immunoassay and thiobarbituric acid method. RESULTS: Mean serum sICAM-1 and TSA levels were significantly higher in the total patient group than in the control group (p < 0.001). Thus, the correlation between TSA and sICAM-1 became more significant in metastatic breast cancer. There were significant positive correlations between TSA and sICAM-1 in stage I+II (r = 0.59, p < 0.05), stage III (r = 0.47, p < 0.05), and stage IV (r = 0.89, p < 0.01), and total patient group (r = 0.56, p < 0.001). CONCLUSION: SerumsICAM-1 and TSA levels were higher in patients with breast cancer, than that of the control group, and also in the metastatic breast cancer group. Significant correlations between serum sICAM-1 and TSA may reflect the similar function of these molecules as adhesion molecules, and their roles in the carcinogenesis of breast cancer as well as metastasis.

Cerebral fat embolism: pulmonary contusion is a more important etiology than long bone fractures.

Lipid embolism is a serious and life-threatening problem and usually arises as a complication of severe trauma associated with long bone or pelvic fractures. It is generally thought that fat droplets enter the circulation at the site of fracture. In the systemic circulation, they become emboli to brain, kidney and other areas. Lipids are absorbed from the intestinal tract and transported into pulmonary tissue via thoracic duct and exposed to first catabolic procedures in the lungs. We have predicted that systemic lipid embolism may not occur unless bone fractures lead to pulmonary injury. This study was planned to investigate this hypothesis with respect to the role of pulmonary contusion and long bone fractures in the formation of cerebral fat embolism. Twenty male hybrid rabbits were included in this study. Pulmonary contusion was performed on half of the rabbits (n = 10) and femur fracture was applied to the remaining ones (n = 10). Ten days after procedure, all rabbits were sacrificed. Brain specimens were taken by frozen-section method and stained with Sudan black. Intraarteriolar lipid particles in the brain were examined microscopically. Cerebral fat embolism was detected in seven animals exposed to pulmonary contusion and only in one animal exposed to femur fracture. The mean number of branches of middle cerebral artery at midparietal level occluded with fat particles were higher in the pulmonary contusion group than in the long bone fracture group. In conclusion, we found that pulmonary contusion had more deleterious effects than long bone fracture in the formation of cerebral fat embolism.

The effect of individualized diet challenges consisting of allergenic foods on TNF-alpha and IL-1beta levels in patients with rheumatoid arthritis.

OBJECTIVE: To investigate the effect of individualized diet challenges consisting of allergenic foods, defined by the skin prick test (SPT), on tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) levels in patients with rheumatoid arthritis (RA). METHODS: Twenty patients with a positive SPT response for food extracts and 20 with a negative SPT response were enrolled. None of the patients had active disease. All patients were fasted for the most common allergenic foods for 12 days and then allocated to two groups according to SPT results. Food challenges were performed with allergenic foods in the prick-positive group (PPG) and with corn and rice in the prick-negative group (PNG) for a period of 12 days. Then, allergenic foods were excluded from the PPG patients' diet and corn and rice were removed from the PNG patients' diet. Clinical examinations were performed after fasting (baseline), at the end of the challenge phase and at the end of the re-elimination phase. Stiffness, pain, tender and swollen joint counts, health assessment questionnaire (HAQ), Ritchie's articular index, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and serum TNF-alpha and IL-1beta levels were measured. RESULTS: TNF-alpha (P < 0.01), IL-1beta (P < 0.05), ESR (P < 0.05) and CRP (P = 0.001) levels and all of the clinical variables, except HAQ, were increased with food challenges in the PPG. These increases were also recorded after the re-elimination phase. In the PNG, no significant change was seen in any of the variables, except pain (P < 0.05). During the study, important differences were observed for most of the variables between the two groups. Thirteen (72%) patients in the PPG and three (18%) in the PNG experienced disease exacerbation with challenges. This aggravation continued after elimination. CONCLUSIONS: Our results suggest that individualized dietary revisions may regulate TNF-alpha and IL-1beta levels in selected patients with RA.

Levels of soluble intercellular adhesion molecule-1 and total sialic acid in serum of patients with laryngeal cancer.

BACKGROUND: Adhesion molecules have been implicated in tumor progression. In this study, we aimed to investigate serum soluble intercellular adhesion molecule-1 (sICAM-1) and total sialic acid (TSA) levels in laryngeal carcinoma and correlate their levels with the cancer stage. METHOD: The sera from 35 patients with laryngeal cancer (10 at stage II, 12 at stage III and 13 at stage IV) were extracted before treatment. The concentrations of sICAM-1 and TSA were measured by enzyme-linked immunoassay and the thiobarbituric acid method, respectively and compared with those from a healthy control group (n = 34). RESULTS: Mean serum sICAM-1 and TSA levels were found to be higher in the total patient group (the lowest level belonging to stage II) than in the control group (p < 0.001, control versus total patient group). As the stage of the disease increased, higher levels of sICAM-1 and TSA were determined. The correlations between TSA and sICAM-1 became more significant as the stage of the disease increased (r= 0.67, p < 0.05 in stage II, r= 0.86, p < 0.001 in stage III and r = 0.90, p < 0.001 in stage IV). CONCLUSION: These data reveal that the significant correlations between sICAM-1 and TSA in laryngeal cancer, more prominent at advanced stage, might reflect the similar nature of these molecules, which function as adhesion molecules.

Estradiol and nitric oxide in men over 50 years of age.

We measured the circulatory levels of nitric oxide and estradiol in men over 50 years with estrogenisation findings. We investigated relation between nitric oxide, which is the principal signal for relaxation of vascular smooth muscle cells, and estradiol levels in serum in men over 50 years with estrogenisation. This study included 14 men with (group 1) and 20 without estrogenisation findings (group 2). Mean nitric oxide and estradiol levels were found to be significantly lower in group 2 than group 1. Group 2 had lower levels sex-hormone binding globin and higher both systolic and diastolic blood pressure values than group 1. There was a significant correlation between nitric oxide and estradiol in esrogenisation group.

Serum 1,25 dihydroxy vitamin D (1,25(OH)2D3), 25 hydroxy vitamin D (25(OH)D) and parathormone levels in diabetic retinopathy.

OBJECTIVES: To investigate whether there is a relationship between serum 1,25 dihydroxy vitamin D3 [1,25(OH)2D3], which is an inhibitor of angiogenesis, concentrations and severity of diabetic retinopathy (DR). DESIGN AND METHODS: Serum 1,25(OH)2D3, 25 hydroxy vitamin D [25(OH)D] and parathormone (PTH) concentrations were measured in diabetic patients (n = 66) and nondiabetic healthy subjects (n = 20). RESULTS: The mean serum 1,25(OH)2D3 concentration in diabetic patients was lower than that in nondiabetics (57.3+/-21.44 vs. 89.4+/-18.01 pmol/L, p<0.001); mean 1,25(OH)2D3 concentrations fell with increasing severity of DR [being 63.4+/-17.26 pmol/L for background DR (BDR), 47.7+/-13.27 pmol/L for preproliferative DR (pre-PDR), and 43.1+/-19.45 pmol/L for proliferative DR (PDR)]. Compared with the control group, serum 25(OH)D concentrations were found to be decreased in diabetic patients (p<0.001). There were negative correlations between 1,25(OH)2D3 and age (r = -0.331, p<0.01) and duration of diabetes (r = -0.255, p<0.05). CONCLUSION: From these findings, it was found that there was an inverse relationship between the severity of the retinopathy, i.e., neovascularization, and serum 1,25(OH)2D3 concentrations, being the lowest in PDR and the highest in diabetic patients without retinopathy (NDR) patients. The measurement of serum 1,25(OH)2D3 concentrations might be helpful to predict severity of DR in patients with diabetes mellitus.

Erythrocyte superoxide dismutase and glutathione peroxidase activities, and malondialdehyde and reduced glutathione levels in schizophrenic patients.

There is abundant evidence that free radicals are involved in membrane pathology in the central nervous system and that they may play a role in neuropsychiatric disorders, including schizophrenia. In this study, we investigated erythrocyte superoxide dismutase and glutathione peroxidase activities as antioxidant enzymes, malondialdehydes as a sign of lipid peroxidation, and reduced glutathione levels in schizophrenic patients. Activities of superoxide dismutase and levels of malondialdehyde in erythrocytes were greater in all patients (n=48) and in patients with acute (n=16) and chronic schizophrenia (n=32) (p<0.001 for all patients and chronic patient group; p<0.05 for acute patient group). The activities of glutathione peroxidase were lower in patients (p<0.05 for all patients and acute patient group; p=0.051 for chronic patient group) compared with the control group. Mean erythrocyte reduced glutathione was lower in patients than in controls (p<0.05). In the patient group, erythrocyte superoxide dismutase activity was positively correlated with scales and duration of disease and erythrocyte malondialdehyde concentration. These data reveal that antioxidative defense mechanisms might be impaired in schizophrenic patients.

Sialic acid, transketolase and Na+, K+, ATPase in patients with rheumatoid arthritis.

We studied transketolase activity of red blood cell hemolysates, and Na+, K+, ATPase activity and sialic acid concentration in red blood cell membranes from 52 patients with rheumatoid arthritis and 24 control subjects. Decreased red blood cell membrane Na+, K+, ATPase activity and sialic acid concentration and decreased transketolase in red blood cell hemolysates were observed in rheumatoid arthritis patients compared with control subjects (p < 0.001). Erythrocyte sedimentation rate and C-reactive protein values were increased in rheumatoid arthritis patients compared with control subjects (p < 0.0001). Significant correlations between sialic acid and Na+, K+, ATPase (r = 0.65, p < 0.001) and between sialic acid and transketolase (r = 0.58, p < 0.001) were observed. Erythrocyte sedimentation rate and C-reactive protein levels did not correlate with Na+, K+, ATPase activity or with sialic acid or transketolase in rheumatoid arthritis patients. These data show that decreases in Na+, K+, ATPase, and transketolase activities and sialic acid concentration are present in rheumatoid arthritis patients, and that the decrease in Na+, K+, ATPase and transketolase activities in rheumatoid arthritis might be due to decreased sialic acid.

An enzymatic method for the determination of free fatty acids in serum/plasma.

Estimation of serum free fatty acids (FFA) in serum based on the formation of inorganic phosphate has been simplified by eliminating complex stages. The principle of the present method is based on breakdown of pyrophosphate, formed by thioesterification of free fatty acids with ATP and CoA with the aid of acyl-CoA synthetase (EC 6.2.1.3) to inorganic phosphate. This is measured using the reaction with molybdate. The reaction equations are as follows: [formula: see text] The recovery of free fatty acids was 96%. The interferences of citrate, phosphatidylserine, succinate, ascorbic acid and lecithin were between 0.5 and 2%. The correlation between the new enzymatic and the classic enzymatic method was 0.966. The lower detection limit was 0.018 mmol/l. The method was linear between 0.02 and 2.0 mmol/l. The within-assay and between-assay imprecision (CV) of control sera was 5.5% and 8%, respectively.

The importance of serum transferrin receptor level in the diagnosis of functional iron deficiency due to recombinant human erythropoietin treatment in haemodialysis patients.

In haemodialysis (HD) patients, functional iron deficiency frequently appears due to recombinant human erythropoietin (r-HuEPO) treatment. However, the diagnosis of iron deficiency is not always easy in such patients. Recent studies have shown that the serum transferrin receptor (s-TfR) level is a sensitive, quantitative measure of tissue iron deficiency. In this study, we examined the changes in s-TfR levels in patients with iron deficiency anaemia due to r-HuEPO treatment. We compared s-TfR levels of 24 patients with i.v. administered r-HuEPO (50-70 U/kg/dose) at the end of each dialysis session (three times a week) and diagnosed as having iron deficiency anaemia by routine laboratory methods (ferritin <50 microg/l and transferrin saturation <16%) with s-TfR levels of 32 patients not receiving r-HuEPO and without iron deficiency anaemia. Also, 40 healthy volunteer subjects were included in the study as a control group. Serum ferritin and transferrin receptor levels were measured with ELISAs using monoclonal reagents. There were no differences between the two groups with and without iron deficiency anaemia with respect to mean age, body weight, haemodialysis duration, haemoglobin and serum creatinine levels (p>0.05). For s-TfR levels, while no difference was present between the control and the non-iron deficiency groups (p>0.05), the iron deficiency group had higher s-TfR values than those of both the control and non-iron deficiency groups (p<0.001). Besides, there was an inverse correlation between haemoglobin and s-TfR levels in patients with iron deficiency anaemia (r = -0.85, p<0.0001). We conclude that the measurement of s-TfR levels may be useful in the diagnosis of functional iron deficiency in haemodialysis patients receiving r-HuEPO.

Glutathione and nitric oxide concentrations in glutamine-infused rabbits with intestinal ischaemia/reperfusion.

Intestinal ischaemia/reperfusion causes formation of reactive oxygen intermediates which lead to mucosal cell injury. Glutathione, a scavenger of reactive oxygen intermediates, protects tissues from reactive oxygen intermediate-mediated cell injury. Nitric oxide is a lipophilic gas and its synthesis is stimulated by ischaemic conditions. In this experimental study, we aimed to investigate the role of i. v. L-glutamine infusion on mucosal tissue glutathione and serum nitric oxide concentrations in intestinal ischaemia/reperfusion. External jugular vein of albino rabbits was cannulated with catheter and infused with normal saline at 4 ml/h. After 3 days, they were randomly divided into two main groups. Group 1 (n = 30) received i. v. normal saline alone, group 2 (n = 30) received normal saline + 205 mmol/l glutamine at 4 ml/h for 24 hours. Next, mucosal glutathione and serum nitric oxide concentrations were measured after 0, 30, 60 min of ischaemia/60 min of reperfusion. Basal glutathione concentrations were similar in normal saline alone and normal saline + 205 mmol/l glutamine infusion groups (p > 0.05). At 30 and 60 min of ischaemia/60 min of reperfusion, glutathione concentrations were significantly lower in normal saline-infused rabbits compared to the normal saline + 205 mmol/l glutamine-infused rabbits (p < 0.05). In addition, serum nitric oxide concentrations were found to be significantly increased in rabbits 30 and 60 min after ischaemia/reperfusion when compared to mean basal nitric oxide concentrations obtained from control animals. However, the normal saline + 205 mmol/l glutamine group had lower serum nitric oxide concentrations than did the normal saline alone group. In conclusion, this study revealed that intestinal mucosal glutathione concentrations were significantly higher in glutamine-receiving rabbits than in non-receiving ones. Additionally, it was shown that nitric oxide concentrations increased in ischaemia both in normal saline alone and normal saline + 205 mmol/l glutamine receiving groups, while this increase in nitric oxide was more prominent in the normal saline alone group (p < 0.01). These findings show that glutamine supplementation may protect the small intestine from ischaemia/reperfusion injury and may play a regulatory role in the biosynthesis of nitric oxide.

Reduced lecithin: cholesterol acyltransferase (LCAT) and Na+, K+, ATPase activity in diabetic patients.

OBJECTIVE: To investigate the plasma concentrations of lecithin:cholesterol acyltransferase (LCAT EC 2.3.1.43) and erythrocyte membrane Na+, K+, ATPase and the correlation of these parameters in diabetes mellitus. DESIGN AND METHODS: Na+, K+, ATPase was measured with spectrophotometric method and LCAT with radioactive method in 19 patients with insulin-dependent diabetes mellitus (IDDM), in 20 with non-insulin-dependent diabetes mellitus (NIDDM) and in 20 healthy volunteers as the control group. RESULTS: Compared with the control group, plasma LCAT concentrations were found to be decreased in both of the patient groups (p < 0.01 for both). Erythrocyte membrane Na+, K+, ATPase activities were higher in the controls than both in the NIDDM and IDDM groups (p < 0.01 and p < 0.001, respectively). There were significant correlations between LCAT and Na+, K+, ATPase in IDDM (r = 0.82, p < 0.001) and in NIDDM (r = 0.74, p < 0.001). In order to investigate the effect of cholesterol (C) and lysophosphatidylcholine (LPC) on Na+, K+, ATPase activity, this enzyme's activity was determined in erythrocyte membranes obtained from diabetic subjects after in vitro incubation with increasing concentrations of LPC and C (2-10 microM). Enzymatic activity was significantly reduced by in vitro C at increasing concentrations but significantly increased by in vitro LPC at increasing concentrations. CONCLUSIONS: From these data, it is to be concluded that the decrease in Na+, K+, ATPase activity in diabetes might be due to decreased LCAT concentrations and that may explain the development of atherosclerosis in diabetics.