Comparison of blood gas, electrolyte and metabolite results measured with two different blood gas analyzers and a core laboratory analyzer.

BACKGROUND: Blood gas analyzers (BGAs) are important in assessing and monitoring critically ill patients. However, the random use of BGAs to measure blood gases, electrolytes and metabolites increases the variability in test results. Therefore, this study aimed to investigate the correlation of blood gas, electrolyte and metabolite results measured with two BGAs and a core laboratory analyzer. METHODS: A total of 40 arterial blood gas samples were analyzed with two BGAs [(Nova Stat Profile Critical Care Xpress (Nova Biomedical, Waltham, MA, USA) and Siemens Rapidlab 1265 (Siemens Healthcare Diagnostics Inc., Tarrytown, NY, USA)) and a core laboratory analyzer [Olympus AU 2700 autoanalyzer (Beckman-Coulter, Inc., Fullerton, CA, USA)]. The results of pH, pCO2, pO2, SO2, sodium (Na⁺), potassium (K⁺), calcium (Ca⁺²), chloride (Cl⁻), glucose, and lactate were compared by Passing-Bablok regression analysis and Bland-Altman plots. RESULTS: The present study showed that there was negligible variability of blood gases (pCO2, pO2, SO2), K⁺ and lactate values between the blood gas and core laboratory analyzers. However, the differences in pH were modest, while Na⁺, Cl⁻, Ca²âº and glucose showed poor correlation according to the concordance correlation coefficient. CONCLUSIONS: BGAs and core laboratory autoanalyzer demonstrated variable performances and not all tests met minimum performance goals. It is important that clinicians and laboratories are aware of the limitations of their assays.

Serum neuron-specific enolase and S-100ß levels as prognostic follow-up markers for oxygen administered carbon monoxide intoxication cases.

Serum neuron-specific enolase (NSE) and S-100ß levels are considered novel biochemical markers of neuronal cell injury. In this study, the initial and post-treatment levels of NSE and S-100ß were compared in carbon monoxide (CO) poisoning patients, who received normorbaric oxygen (NBO) or hyperbaric oxygen (HBO) therapy. Forty consecutive patients with acute CO poisoning were enrolled in this prospective, observational study. According to their clinical symptoms and observations, twenty patients were treated with NBO, and the other twenty with HBO. Serum S-100ß and NSE levels were measured both at time of admission and 6 h later (post-treatment). Serum NSE and S-100ß values decreased significantly in both of the therapeutic modalities. The initial and post-treatment values of NSE and S-100ß in NBO or HBO patients were comparable. A clear negative correlation was observed between the decrease of NSE and S-100ß levels and initial blood carboxyhemoglobin levels. In conclusion, the present results suggested the use of serum S-100ß and NSE levels as indicators for brain injury. Due to the significant increase of their values with oxygen therapy, they may also be useful as prognostic follow-up markers. However, the current findings reflected no difference between the efficacy of NBO or HBO therapy.

Determination of oxidative stress and cellular inflammation in patients with diabetic nephropathy and non-diabetic nephropathy being administered hemodialysis treatment due to chronic renal failure.

OBJECTIVES: We aimed to evaluate oxidative stress [8-hydroxydeoxyguanosine (8-OHdG), malondialdehyde (MDA)] endothelial damage [asymmetric dimethylarginine (ADMA)] and markers of cellular inflammation [interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), neopterin (NP) and high-sensitivity C-reactive protein (hsCRP)] in patients with diabetic nephropathy (DN) and non-diabetic nephropathy who were being administered hemodialysis treatment because of chronic renal failure. METHODS: In determining 8-OHdG, IL-6 and TNF-α levels, Enzyme-Linked Immuno-Sorbent Assay method was used. Serum MDA, ADMA and NP levels were determined by using high performance liquid chromatography (HPLC). And hs-CRP values were measured with nephelometric method. RESULTS: Serum 8-OHdG and MDA levels were found statistically to have increased when compared with those of the control group in patients groups after dialysis. However, serum ADMA and neopterin levels were observed statistically to have decreased when compared with those of the control group in patients groups after dialysis. But, decreases on ADMA and neopterin levels are still much higher than those of control. IL-6 and TNF-α levels were found to have increased when compared with those of control group in patients groups before dialysis. CONCLUSION: The oxidative stress in patients with DN, who were being treated with hemodialysis due to chronic renal failure, was higher than that of non-DN patients who were being treated with hemodialysis. In contrast with this, inflammation occurring in non-DN patients was found to have been higher than that of in patients with DN.

Investigation of endoplasmic reticulum stress-regulated chaperones as biomarkers in idiopathic non-obstructive azoospermia.

Azoospermia is a condition in which sperm cells are completely absent in a male's ejaculate. Typically, sperm production occurs in the testes and is regulated by a complex series of cellular and molecular interactions. Endoplasmic reticulum (ER) stress arises when there is deviation from or damage to the normal functions of the ER within cells. In response to this stress, a cascade of response mechanisms is activated to regulate ER stress within cells. This study aims to investigate the role of endoplasmic reticulum (ER) stress-regulated chaperones as potential biomarkers in male infertility. ER stress associated with azoospermia can manifest in cells such as spermatogonia in the testes and can impact sperm production. As a result of ER stress, the expression and activity of a variety of proteins within cells can be altered. Among these proteins are chaperone proteins that regulate the ER stress response. The sample size was calculated to be a minimum of 36 patients each groups. In this preliminary study, we measured and compared serum levels of protein disulfide-isomerase A1 (PDI1), protein disulfide-isomerase A3 (PDIA3), mesencephalic astrocyte-derived neurotrophic factor (MANF), glucose regulatory protein 78 (GRP78), clusterin (CLU), calreticulin (CRT), and calnexin (CNX) between male subjects with idiopathic non-obstructive azoospermia and a control group of non-infertile males. Serum PDIA1 (p=0.0004), MANF (p=0.018), PDIA3 (p<0.0001), GRP78 (p=0.0027), CRT (p=0.0009) levels were higher in the infertile group compared to the control. In summary, this study presents novel findings in a cohort of male infertile patients, emphasizing the significance of incorporating diverse biomarkers. It underscores the promising role of ER stress-regulated proteins as potential serum indicators for male infertility. By elucidating the impact of ER stress on spermatogenic cells, the research illuminates the maintenance or disruption of cellular health. A deeper understanding of these results could open the door to novel treatment approaches for reproductive conditions including azoospermia.

Evaluation of mid-regional pro-atrial natriuretic peptide, procalcitonin, and mid-regional pro-adrenomedullin for the diagnosis and risk stratification of dyspneic ED patients.

OBJECTIVE: The aim of this study was to evaluate the diagnostic and the prognostic value of a laboratory panel consisting of mid-regional pro-atrial natriuretic peptide (MR-proANP), procalcitonin (PCT), and mid-regional pro-adrenomedullin (MR-proADM) for patients presenting to the emergency department (ED) with acute dyspnea. METHODS: We prospectively enrolled ED patients who presented with a chief complaint of dyspnea and who had an uncertain diagnosis after physician evaluation. Final primary diagnosis of the cause of shortness of breath was confirmed through additional testing per physician discretion. We recorded inpatient admission and 30-day mortality rates. RESULTS: One hundred fifty-four patients were enrolled in the study. Congestive heart failure exacerbation was the final primary diagnosis in 42.2% of patients, while infectious etiology was diagnosed in 33.1% of patients. For the diagnosis of congestive heart failure exacerbation, MR-proANP had a sensitivity of 92.7% and specificity of 36.8%, with a negative likelihood ratio (LR-) of 0.16 and a positive likelihood ratio (LR+) of 1.44 (cut-off value: 120 pmol/L). For the diagnosis of an infectious etiology, PCT had a 96.5% specificity and 48.8% sensitivity (LR-: 0.58, LR+: 13.8, cutoff value: 0.25 ng/mL). As a prognostic indicator, MR-proADM demonstrated similar values: odds ratio for 30-day mortality was 8.5 (95% CI, 2.5-28.5, cutoff value: 1.5 nmol/L) and the area under the receiver operating characteristic curve in predicting mortality was 0.81 (95% CI, 0.71-0.91). CONCLUSION: The good negative LR- of MR-proANP and the good positive LR+ of PCT may suggest a role for these markers in the early diagnosis of ED patients with dyspnea. Furthermore, MR-proADM may assist in risk stratification and prognosis in these patients..

The levels of nitric oxide and asymmetric dimethylarginine in the rat endometriosis model.

AIM: To investigate the levels of nitric oxide (NO) and asymmetric dimethylarginine (ADMA) in all the rat endometriosis models. MATERIAL & METHODS: Forty-one rats with endometriotic implants were divided into four groups (1 to 4) and administered infliximab, etanercept, letrozole and control, respectively. There were 11 rats in group 5 (normal). The size of implants, plasma ADMA and nitrate/nitrite (NO(x) ) levels and histological score were assessed. RESULTS: In groups 1, 2 and 3, plasma ADMA levels were higher than groups 4 and 5, 296.8 ± 66.2, 285.9 ± 35.7, 200.3 ± 41.0, 125.3 ± 16.7, 111.3 ± 6.5 µmol/L, respectively, while NO(x) levels were lower than groups of control and normal 19.6 ± 3.8, 19.8 ± 4.4, 39.3 ± 6.1, 80.5 ± 5.3, and 91.1 ± 5.0 µmol/L, respectively. CONCLUSIONS: Infliximab, etanercept and letrozole have regressed endometriotic implants, decreased plasma NO(x) levels, and increased plasma ADMA levels.

Cord blood and maternal serum neopterin concentrations in patients with pre-eclampsia.

BACKGROUND: Pre-eclampsia is a syndrome characterized by hypertension and proteinuria. The aim of this study was to investigate neopterin concentrations in cord blood and maternal serum in patients with pre-eclampsia and a control group. METHODS: Cord blood and maternal serum neopterin were measured in 21 patients with pre-eclampsia and in 27 control subjects. Neopterin concentrations were measured by high performance liquid chromatography. RESULTS: Cord blood neopterin concentrations were significantly increased in patients with pre-eclampsia compared to controls (54.3+/-16.8 vs. 43.4+/-8.5 nmol/L, p=0.011, respectively). Maternal serum neopterin (257.3+/-36.8 vs. 150.9+/-33.8 nmol/L, p<0.001) was also higher in patients with pre-eclampsia. CONCLUSIONS: Cord blood and maternal serum neopterin concentrations are higher in patients with pre-eclampsia. Maternal serum neopterin concentrations used may be used as a marker for the early diagnosis of pre-eclampsia.

The association between neopterin and acetaminophen-induced nephrotoxicity.

INTRODUCTION: In large dosages, acetaminophen (APAP) produces acute kidney necrosis in most mammalian species. High neopterin levels have been accepted as strong indicators for the clinical severity of some diseases. In this study, we aimed to evaluate whether neopterin is a biomarker in the identification of APAP-induced nephrotoxicity. MATERIALS AND METHODS: Thirty adult male Wistar rats were randomly divided into three groups: control, APAP-1, and APAP-2 groups. APAP-1 and APAP-2 group rats were given a single dose of 1 and 2 g/kg body weight of APAP by gastric tube, respectively. Kidney tissues and blood samples were obtained for biochemical and histopathological analyses. Biochemical parameters, serum and kidney neopterin levels, and the grade of tubular injury were compared in the control, APAP-1, and APAP-2 group animals. RESULTS: APAP treatments caused tubular necrosis in the kidney and increase in serum creatinine concentrations accompanied by elevated serum and kidney neopterin levels. In the rats of groups APAP-1 and APAP-2 when compared with that of the control group (109.1 pmol/mg protein), median kidney neopterin concentrations were 162.1 (p = 0.089) and 222.2 (p < 0.001) pmol/mg protein, respectively. The grade of tubular injury of the APAP-1 and APAP-2 groups was higher than the group of control (both p < 0.001). CONCLUSIONS: Serum and kidney neopterin levels could be sensible alternative to evaluate the risk to have nephrotoxicity because of APAP overdose. The elevated serum and kidney neopterin in the APAP-induced tubular necrosis might be a marker of acute histological kidney injury.

Crucial markers showing the risk of coronary artery disease in obesity: ADMA and neopterin.

BACKGROUND: Obesity is responsible for high morbidity and mortality, both in developed and developing countries. It is associated with many chronic and metabolic diseases. Asymmetric dimethylarginine (ADMA) has been demonstrated to be a biomarker of endothelial dysfunction in humans and increased ADMA associated with cardiovascular disease (CVD) risk has been reported in many states. Neopterin (NP) produced by monocytes/macrophages in response to stimulation by interferon-gamma (IFN-γ) is emphasized in recent findings. The current study aims to investigate ADMA and NP levels which may assume a role in guiding the early diagnosis of coronary artery disease in obesity. METHODS: This is an original research study in which ADMA and NP levels of 50 patients (25 male/25 female) diagnosed with obesity were compared with those of 30 healthy individuals (15 male/15 female) as control. The high-performance liquid chromatography (HPLC) method was used while determining parameters. RESULTS: ADMA and NP levels in obese individuals were found to be significantly higher than in those enrolled in the control. ADMA values were found to be higher in obese subjects (0.71±0.24 µmol/L) as compared with levels found in healthy subjects (0.58±0.16 µmol/L) (p<0.05). A significant increase of serum neopterin levels was found in obese subjects (8.8±3.5 µmol/L) as compared with controls (4.9±1.69 µmol/L) (p<0.05). Also, there was a strong positive correlation between NP and ADMA values in obese individuals (r=0.954). CONCLUSIONS: Our study revealed that obese subjects have higher ADMA and neopterin levels. These results demonstrated that both ADMA and NP levels may be potential risk factors for coronary heart disease in obesity.

Relations between concentrations of asymmetric dimethylarginine and neopterin as potential risk factors for cardiovascular diseases in haemodialysis-treated patients.

OBJECTIVES: To investigate the correlation between concentrations of asymmetric dimethylarginine (ADMA) and neopterin (NP) as potential risk factors for cardiovascular diseases in chronic renal failure patients. METHOD: In this study, 33 patients with renal failure before and after haemodialysis were compared with healthy control subjects. Serum ADMA and NP levels were measured using high performance liquid chromatography (HPLC). RESULTS: When ADMA and NP concentrations in renal failure patients were compared before and after dialysis, before dialysis ADMA and NP concentrations were higher than those in the control group. However, ADMA and NP levels showed a falling mean and clear after dialysis. While there is no correlation between ADMA and NP levels before dialysis, there is a mean and positive correlation between ADMA and NP levels after dialysis. CONCLUSION: Potential risk factors for cardiovascular diseases include high concentrations of both ADMA and NP levels in chronic renal failure patients. A correlation mean between ADMA and NP levels after dialysis was found, but no correlation between ADMA and NP levels before haemodialysis was discovered. These can be evaluated as two different risk factors independent from each other.

Serum HDL-C levels, log (TG/HDL-C) values and serum total cholesterol/HDL-C ratios significantly correlate with radiological extent of disease in patients with community-acquired pneumonia.

BACKGROUND: In several studies, it was shown that there was a marked decrease in serum levels of HDL-C during infection and inflammation in general. In particular, a decrease in the level of serum HDL-C was also shown in pneumonia. Correlations between inflammatory markers such as acute phase proteins, cytokines and serum HDL-C levels were shown. However, there are no studies indicating a correlation between serum HDL-C levels and the radiological extent of the disease (RED) in community-acquired pneumonia (CAP). AIM: We hypothesized that there could be a relationship between serum HDL-C levels and RED in CAP. MATERIALS AND METHODS: A case-controlled study, including 97 patients with CAP and 45 healthy subjects, was performed. Chest X-rays of CAP patients were scored for RED, and correlations were investigated between RED scores, serum lipid parameters, the erythrocyte sedimentation rate (ESR) and serum albumin levels. RESULTS: The mean serum HDL-C level was lower in CAP patients than in controls. A significant and negative correlation between RED scores (REDS) and serum HDL-C levels was detected (r = -0.64, P = 0.0001). There were also significant correlations between REDS and other lipid parameters. Significant correlations between ESR and serum HDL-C levels and between ESR and other serum lipid parameters were also found. CONCLUSION: It appears that serum HDL-C levels are generally lower in CAP cases than in healthy controls. Serum HDL-C levels and serum albumin levels might decrease and serum total cholesterol/HDL-C ratios and log (TG/HDL-C) values might increase proportionally with RED in CAP patients. These results might have some significance for individuals having long-standing and/or recurrent pneumonia and other cardiovascular risk factors.

Elevated plasma concentration of asymmetric dimethylarginine that is reduced by single dose testosterone administration in idiopathic hypogonadotropic hypogonadism patients.

Our aim was to investigate whether plasma l-arginine and asymmetric dimethylarginine (ADMA) concentrations and nitric oxide (NO) production are altered in male idiopathic hypogonadotropic hypogonadism (IHH) patients in the hypogonadal state and after single dose testosterone administration compared with those in control subjects. Eighteen newly diagnosed male patients with IHH and 20 healthy volunteer controls matched by age and body mass index were enrolled in the study. Single dose testosterone was administrated im. Initially, pretreatment blood samples were collected after overnight fasting. Posttreatment blood samples were drawn 10 d after the injection. ADMA, l-arginine, and NO were measured in pre- and posttreatment blood samples. The pretreatment ADMA and l-arginine levels were significantly higher, and plasma nitrite plus nitrate (NOx) levels were lower than those in the control group. After 10 d of treatment, ADMA and l-arginine levels were significantly reduced, and NOx levels were significantly increased. There was a significant positive correlation (P < 0.01) between ADMA and l-arginine and a negative correlation between ADMA and NOx levels in patients and controls. In conclusion, the patients with IHH showed elevated plasma ADMA levels associated with a reduction in NO production. Single dose parenteral T administration lowered ADMA concentrations and increased NO production to the control group values.

Elevated urine neopterin levels in nonalcoholic steatohepatitis.

OBJECTIVES: The aim of this study was to relate urine levels of neopterin, a marker of activation of the cellular immune system, with grading and staging of NASH. DESIGN AND METHODS: Urine concentrations of neopterin, routine tests, insulin and C-peptide levels were assessed in 50 patients with NASH, 25 patients with chronic viral hepatitis (CVH), and in 26 healthy controls. RESULTS: Urine neopterin levels were found elevated in the NASH and CVH groups compared with controls. There was no significant correlation between urine neopterin levels and inflammation grade in the liver. CONCLUSIONS: Urine neopterin levels are a marker of cellular immunity and are higher in patients with NASH. However, neopterin levels were not significantly associated with histopathological grade and stage of disease.

Pleural fluid and serum procalcitonin as diagnostic tools in tuberculous pleurisy.

BACKGROUND: Diagnosis of tuberculous pleuritis is difficult because of its nonspecific clinical presentation and decreased efficiency of traditional diagnostic methods. We investigated the use of procalcitonin (PCT) concentration in tuberculous pleuritis diagnosis. METHODS: A prospective clinical study was performed with two different patient groups. A total of 28 patients were included: 18 with tuberculosis and 10 with nontuberculous pleurisy. Serum and pleural fluid PCT concentrations were evaluated before treatment. RESULTS: Serum and pleural fluid PCT concentrations were statistically different between tuberculous and nontuberculous pleurisy groups (P = 0.012 and P = 0.004, respectively), even though they were not elevated in relation to the cut-off level of 0.5 ng/mL. A positive and significant correlation was detected between serum and pleural fluid PCT levels (r = 0.49, P = 0.008). Diagnostic specificity and sensitivity values for serum and pleural fluid PCT in discriminating tuberculous from nontuberculous pleurisy were 80% and 72.2%, and 90% and 66.7% at the 0.081 and 0.113 ng/mL cut-off values, respectively. CONCLUSION: Relative to the current cut-off level of 0.5 ng/mL, PCT concentration is not a useful parameter for the diagnosis of tuberculous pleurisy. Because there were PCT levels in patients with tuberculous pleurisy that were below the current cut-off level but were significantly different from those of the nontuberculous group, the use of PCT should be further investigated.

The effects of chronic ethanol consumption and withdrawal on passive avoidance task and serum cholinesterase level in rats.

The effects of chronic ethanol consumption and ethanol withdrawal on serum cholinesterase (ChE) activity and passive avoidance task in rats were investigated. Ethanol was administered to rats by a modified liquid diet with 4.8% (v/v) ethanol for 3 days followed by 25 days on a liquid diet in which the ethanol concentration was increased to 7.2%. Control rats were pair fed with an isocaloric liquid diet not containing ethanol. ChE activity and blood ethanol concentration were measured at the end of the 4.8% ethanol consumption and after 25 days of ethanol (7.2%) feeding and, just before and 24th and 72nd h of ethanol withdrawal period. Passive avoidance acquisition was evaluated for 150 s (cut-off time) in three individual groups of ethanol-administered, ethanol withdrawn (24th and 72nd h of withdrawal) and control rats. Locomotor activity of the rats was also measured and evaluated. The daily ethanol consumption of the rats ranged from 11.5 to 14.9 g/kg. ChE activities of the ethanol feeding rats were significantly increased as compared to control rats at the 3rd (4.8% ethanol) and 25th days of chronic ethanol (7.2%) consumption and 24th h of ethanol withdrawal. It returned to control values at the 72nd h of the withdrawal. Blood ethanol levels were measured as 200 and 2.2 mg/dl at just before ethanol withdrawal and 24th h of ethanol withdrawal, respectively. Both chronic ethanol consumption and late period of ethanol withdrawal produced some significant decreases in passive avoidance latency of the rats. Our results suggest that chronic ethanol consumption and late period of ethanol withdrawal may be related to impairment of passive avoidance task in rats. In addition, serum ChE levels do not seem to be involved in impairment of cognitive functions in ethanol dependent-rats.

Effect of macro-creatine kinase and increased creatine kinase BB on the rapid diagnosis of patients with suspected acute myocardial infarction in the emergency department.

Although there are more sensitive and earlier diagnostic markers for the diagnosis of acute myocardial infarction (AMI), measurement of creatine kinase (CK) MB isoenzyme (CKMB) using the immunoinhibition method is still widely used in stat laboratories. In this study, 3,290 patients with the prediagnosis of AMI underwent physical examinations, electrocardiography, and repetitive measurements of CK, CKMB activity, and CKMB mass, and 304 of them were diagnosed as having AMI. Electrophoresis of CK and CKMB mass was performed for the samples from 415 patients whose CKMB activity values were found to be increased and were not correlated with total CK levels. According to CKMB activity, CK electrophoresis, and CKMB index (100 x CKMB activity/CK) values, macro-CK (MCK) and/or increased CKBB levels were detected in 27 cases (MCK-I in 10 cases, MCK-II in 9, increased CKBB in 5, and both MCK-II and increased CKBB in 3). CKMB activity was found to be increased for all except one patient (96.3%), and the CKMB index was >25% in 25 (92.5%) of 27 cases. CKMB mass values were within the normal range in 25 of the cases with MCK. Two patients with MCK-I were diagnosed as having AMI because of increased CKMB mass and positive electrocardiography findings. The incidence of MCK and/or high CKBB levels (0.82%) in the whole group was similar to that reported for a normal population. MCK existence and increased CKBB levels may cause misleading diagnoses if CKMB mass measurements and/or CKMB index values are not used together for patients with suspected AMI.

Dog liver glucose-6-phosphate dehydrogenase: purification and kinetic properties.

Glucose-6-phosphate dehydrogenase (G6PD) catalyses the first step of the pentose phosphate pathway which generates NADPH for anabolic pathways and protection systems in liver. G6PD was purified from dog liver with a specific activity of 130 U x mg(-1) and a yield of 18%. PAGE showed two bands on protein staining; only the slower moving band had G6PD activity. The observation of one band on SDS/PAGE with M(r) of 52.5 kDa suggested the faster moving band on native protein staining was the monomeric form of the enzyme. Dog liver G6PD had a pH optimum of 7.8. The activation energy, activation enthalpy, and Q10, for the enzymatic reaction were calculated to be 8.96, 8.34 kcal x mol(-1), and 1.62, respectively.The enzyme obeyed "Rapid Equilibrium Random Bi Bi" kinetic model with Km values of 122 +/- 18 microM for glucose-6-phosphate (G6P) and 10 +/- 1 microM for NADP. G6P and 2-deoxyglucose-6-phosphate were used with catalytic efficiencies (kcat/Km) of 1.86 x 10(6) and 5.55 x 10(6) M(-1) x s(-1), respectively. The intrinsic Km value for 2-deoxyglucose-6-phosphate was 24 +/- 4mM. Deamino-NADP (d-NADP) could replace NADP as coenzyme. With G6P as cosubstrate, Km d-ANADP was 23 +/- 3mM; Km for G6P remained the same as with NADP as coenzyme (122 +/- 18 microM). The catalytic efficiencies of NADP and d-ANADP (G6P as substrate) were 2.28 x 10(7) and 6.76 x 10(6) M(-1) x s(-1), respectively. Dog liver G6PD was inhibited competitively by NADPH (K(i)=12.0 +/- 7.0 microM). Low K(i) indicates tight enzyme:NADPH binding and the importance of NADPH in the regulation of the pentose phosphate pathway.

Effects of chronic ethanol administration and ethanol withdrawal on cyclic guanosine 3',5'-monophosphate (cGMP) levels in the rat brain.

The main objective of the present study is to investigate the possible effects of chronic ethanol consumption and ethanol withdrawal on cyclic guanosine 3', 5'-monophosphate (cGMP) levels in cerebral cortex, striatum, hippocampus and hypothalamus of rat brain. Ethanol was given to female Wistar rats (225-270g) by a liquid diet for 21 days. cGMP levels were measured in respective brain regions using an EIA kit at 7th, 14th and 21st days of ethanol ingestion and at 6th and 24th h of ethanol withdrawal. cGMP levels in cortex, striatum and hippocampus but not hypothalamus were found significantly increased at 14th and 21st days of ethanol consumption. The most prominent increase was observed in striatal tissues (approximately 350%). cGMP levels of striatum and hippocampus were still remaining significantly high at 6th h of ethanol withdrawal. Blood ethanol levels were found as 115.60, 50.0 and 7.0mg/dl just before and after 6 and 24h of ethanol withdrawal, respectively and audiogenic seizures also occurred at 6th h of ethanol withdrawal with an incidence of 75% in individual parallel groups. Our results suggest that changes of cGMP levels in cerebral cortex, striatum and hippocampus might participate in the mechanism of ethanol dependence and withdrawal in rats.

Pentraxin 3 as a potential biomarker of acetaminophen-induced liver injury.

OBJECTIVE: Overdose of acetaminophen (APAP) can lead to severe liver injury in humans and experimental animals. Pentraxin-3 (PTX-3) is produced and released by several cell types. In this study, we aimed to evaluate whether PTX-3 is a potential biomarker in the identification of APAP-induced liver injury. MATERIALS AND METHODS: Thirty adult male Wistar rats were randomly divided into three groups: control, APAP-1 and APAP-2 groups. APAP-1 (1 g/kg) and APAP-2 (2 g/kg) group rats were given APAP by gastric tube. Liver tissues and blood samples were obtained for biochemical and histopathological analysis. Biochemical parameters, plasma and liver PTX-3 levels and degree of liver necrosis were measured in all groups. RESULTS: APAP treatments caused necrosis in liver and accompanied by elevated liver PTX-3 levels after 48 h. In APAP-1 and APAP-2 groups when compared with control group (7.5±3.3 ng/mg protein), mean liver PTX-3 concentrations were 14.1±3.0 (p=0.032) and 28.5±8.2 (p<0.001) ng/mg protein, respectively. All rats (100%) in the APAP-2 group had the degree 3 liver necrosis. However 10%, 40% and 50% of rats had the degree 1, the degree 2 and the degree 3 liver necrosis in the APAP-1 group, respectively. The degrees of liver necrosis of the APAP-1 and APAP-2 groups were higher than the group of control (p<0.001 and p<0.001, respectively). CONCLUSIONS: PTX-3 may have a role in the APAP-induced liver injury in the rats. The elevated liver PTX-3 in the APAP-induced hepatic necrosis might be a marker of acute histological liver damage. Further prospective studies are necessary to clarify the prognostic value of liver PTX-3 for prediction of histological hepatic necrosis in the APAP-induced liver injury.