Circular RNAs 0064286 and 0000475: Potential Diagnostic Biomarkers in Hepatocellular Carcinoma.

OBJECTIVE: Hepatocellular carcinoma (HCC) is considered the highest recorded malignancy in Egypt. The shortage of appropriate biomarkers for early detection often results in the late diagnosis of the HCC. Circular RNAs (CircRNAs) are presented as long stranded non-coding RNA that combine covalently to make a sealed circular form which make them very stable. CircRNAs are known to have interpretative role in cancer development and metastasis. AIM: To examine the dysregulation of two new CircRNAs obtained from Circbase database (hsa_circ_0064286 and hsa_circ_0000475) in the serum of HCC patients as predictable diagnostic biomarkers of HCC and their correlation with some liver biochemical parameters. METHODS: Sixty clinically diagnosed HCC Egyptian patients and 25 healthy volunteers were enrolled in the study. Expression levels of the selected CircRNAs was evaluated in subjects' serum. Moreover, correlation with liver biochemical parameters, sensitivity, and specificity of studied CircRNAs were estimated. RESULTS: Both circular RNAs were significantly down regulated in HCC patients, which was negatively correlated with ALP, ALT, AST, AFP, and bilirubin levels. Circ_0064286 showed more sensitivity and specificity (88.3% and 96%, respectively). CONCLUSION: As far as we know, this is the first study that shed light on the expression levels of both circRNAs in Egyptian HCC patients. They may serve as potential biomarkers for HCC diagnosis. Moreover, those circRNAs draw attention as therapeutic targets for HCC through targeting their sponge miRNAs.

Oxidative stress and bone markers in plasma of patients with long-bone fixative surgery: role of antioxidants.

It is well known that bone markers (e.g. osteocalcin and alkaline phosphatase) play a significant role in healing of bone fractures, whereas oxidative stress delay such healing. The present study aimed to investigate the effect of a mixture of antioxidants (vitamins A, C, E, and selenium) on oxidative stress parameters, and the levels of bone healing markers in the plasma of male patients following fixative surgery of long bones. Antioxidant tablets (300 µg vitamin A, 10 mg vitamin E, 60 mg vitamin C, and 75 µg selenium) were administered to groups 3 and 4 (10 patients in each) for 1 and 2 weeks, respectively, in addition to the regular postoperative treatment. Groups 1 (25 patients) and 2 (10 patients) received the regular post-operative treatment consisting of intravenous (I.V.) second generation of cephalosporin 1000 mg/day for 3 days, oral diclofenac 50 mg, and paracetamol 500 mg twice daily for 15 days. Osteocalcin level and alkaline phosphatase activity as well as antioxidant enzymes superoxide dismutase (SOD), glutathione reductase (GR), as well as glutathione (GSH), and thiobarbituric acid reactive substances (TBARS) as indices of oxidative stress, were determined in the plasma of all patients after 1 or 2 weeks of long-bone fixative surgery. The results revealed that osteocalcin level and the activity of alkaline phosphatase were markedly increased in the plasma of patients who received antioxidants for 2 weeks. In addition, after 1 and/or 2 weeks, the levels of TBARS were significantly lower in the antioxidant-treated patients compared with those who did not receive antioxidants. On the other hand, the activities of SOD and GR were markedly elevated in plasma of patients who received antioxidants after 1 or 2 weeks compared with patients who received regular therapy. Moreover, the level of plasma GSH was markedly increased only after 2 weeks in patients who received antioxidants. It is concluded that administration of antioxidant vitamins A, E, and C in addition to selenium could accelerate bone healing after long-bone fixative surgery. Therefore, antioxidants should be considered in designing therapeutic protocols in post-operative bone surgery.

Smoking and polymorphisms of the interleukin-1 gene cluster (IL-1alpha, IL-1beta, and IL-1RN) in patients with periodontal disease.

BACKGROUND: Polymorphisms within the interleukin-1 cluster are known to be associated with adult periodontal disease. However, interactions of genetic with other risk factors, especially smoking, remain questionable. The aim of this cross-sectional study was to evaluate the genetic influence on periodontal variables in relation to environmental factors. METHODS: One-hundred fifty-four (154) Caucasian subjects were clinically and radiographically assessed for their periodontal status, their smoking history recorded, and their allelic pattern of IL-1alpha, IL-1beta, and IL-1RN polymorphisms determined by genotyping. RESULTS: In assessing periodontitis with mean probing depth, mean attachment loss, or mean bone loss, no differences were found in allele frequencies or combined allotypes between subjects with mild or moderate versus those with severe signs of periodontitis. However, the extent of attachment loss defined as percentage of sites >4 mm was significantly associated with the composite genotype of IL-1alpha/1beta in smokers (odds ratio [OR] = 4.00; 95% confidence interval [CI] 1.03 to 16.70; P= 0.02). No differences were found in genotype negative subjects irrespective of their smoking status. They had nearly identical attachment loss as genotype positive non-smokers. Similar non-significant results were found with respect to extent of bone loss. An increased risk of more extended attachment loss was observed also in individuals carrying mutations of the combined genotype IL-1alpha/IL-1RN, again showing enhanced risk only in genotype-positive and smoking subjects. CONCLUSIONS: The results provide evidence that the composite genotypes studied show interaction with smoking, the main exposition-related risk factor of periodontal disease. Non-smoking subjects are not at increased risk, even if they are genotype-positive.

Polymorphisms of Fc gamma-receptors RIIa, RIIIa, and RIIIb in patients with adult periodontal diseases.

Polymorphisms influencing the binding affinity between the Fcgamma receptors and IgG of different subclasses are thought to be of importance in the individual susceptibility to infections with Gram-negative bacteria contributing to periodontal disease. One hundred and fifty-four Caucasian subjects were clinically and radiographically examined for their periodontal status and genotyped for their allelic pattern of FcgammaRIIa, FcgammaRIIIa, and FcgammaIIIb polymorphism. In assessing periodontitis according to mean probing depth and attachment loss, no differences were found in allele frequencies or combined allotypes between the subjects with mild or moderate and those with severe signs of periodontitis. However, the extent and severity of bone loss were significantly associated with the genotype of the receptor FcgammaRIIIa. An increased risk of severe bone destruction was observed in individuals carrying the FcgammaRIIIa-VV genotype (OR = 5.3; 95% CI 1.4-26.2). FcgammaRIIIb is in linkage disequilibrium with FcgammaRIIIa. Hence it is also related to periodontal disease. There is no indication of an association between the polymorphism of FcgammaRIIa and periodontitis. The results are evidence that the FcgammaRIIIa genotype coding for the high affinity receptor imposes an additional risk of bone loss as does the FcgammaRIIIb genotype coding for the low affinity receptor.

Effective pelvic symptom control using initial chemoradiation without colostomy in metastatic rectal cancer.

PURPOSE: To assess pelvic chemoradiotherapy (CXRT) without colostomy as a component of the multidisciplinary management of patients presenting with metastatic rectal cancer. METHODS AND MATERIALS: Eighty patients with synchronous distant metastases from rectal cancer were treated with initial CXRT. Hypofractionated radiotherapy was administered usually with concurrent 5-FU (92%, 300 mg/m(2)/day, M-F). Three-field belly-board technique was used in 89%. Group 1 had CXRT alone (n = 55). Group 2 (n = 25) patients were selected for primary disease resection, and sometimes HAI chemotherapy (n = 10) or hepatic resection (n = 5). Subsequently, 78% received systemic chemotherapy. RESULTS: Symptoms from primary tumor resolved in 94%. Endoscopic complete clinical response rate was 36%. Two-year survival (11% vs. 46%, p < 0.0001) and symptomatic pelvic control (PC, 81% vs. 91%, p = 0.111) were higher in Group 2, but colostomy-free rate (CFR) was lower (79% vs. 51% p = 0.02). CFR was 87% in Group 1 patients managed initially without fecal diversion (n = 50). Examining all patients using multivariate analysis, pelvic pain at presentation (p < 0.00001), BED (biologic equivalent dose at 2 Gy/fraction) < 35 Gy (p = 0.077), and poor differentiation (0.079) predicted worse PC. Poor differentiation (p = 0.017) and selection for CXRT alone (p < 0.0001) predicted worse survival. There were 4 RTOG of Grade 3 or greater acute complications, 5 severe perioperative complications, and no significant late treatment-related complications. CONCLUSION: Durable PC can be safely achieved without colostomy in most patients presenting with primary rectal cancer and synchronous systemic metastases using hypofractionated pelvic chemoradiation. A BED greater than 35 Gy is recommended. Selected patients appear to benefit from resection of primary disease. Higher doses should be investigated in patients with pelvic pain.

Substance loss caused by scaling with different sonic scaler inserts--an in vitro study.

BACKGROUND, AIMS: Depending on the phase of periodontal treatment, power-driven inserts with different power levels are necessary: during initial treatment and flap operations, it must be possible to remove calculus which firmly adheres to the root surface with great efficiency; in contrast, gentle root-surface instrumentation has a high priority during maintenance treatment. Recently, modified sonic scaler inserts have been introduced: diamond-coated inserts for open flap operations and slim probe-shaped sonic scaler inserts for deplaqueing during maintenance. METHOD: We compared the substance removal by these inserts to that of a conventional insert. In a bench system which allows application force, stroke height, and width and frequency of instrumentation to be monitored and also permits assessment of the topography before and after instrumentation (yielding depth removal and removed volume), we instrumented aluminum rods in triplicate and bovine roots in a 5-fold repetition. RESULTS: With high application forces (1.0 N), the diamond-coated inserts removed 30 to 50% more substance than the conventional one. Except for the slim inserts, there was a significant linear relationship between increasing force and removed volume. Probe-shaped inserts do not remove considerable substance even with increasing pressures. CONCLUSIONS: Diamond-coated inserts remove tooth substance very effectively and must thus be handled with care: more pressure effects more removal. Probe-shaped inserts can be used without risk during maintenance visits.

Effects of volatile oil constituents of Nigella sativa on carbon tetrachloride-induced hepatotoxicity in mice: evidence for antioxidant effects of thymoquinone.

Effects of the volatile oil constituents of Nigella sativa, namely, thymoquinone (TQ), p-cymene and alpha-pinene, on carbon tetrachloride (CCl4-indued acute liver injury were investigated in mice. A single dose of CCl4 (15 microl/Kg i.p.) induced hepatotoxicity 24 h after administration manifested biochemically as significant elevation of the enzymes activities of serum alanine transaminase (ALT, EC:2.6.1.2), asparate transaminase (AST, EC:2.6.1.1) and lactate dehydrogenase (LDH, EC: 1.1.1.27). The toxicity was further evidenced by a significant decrease of non-protein sulfhydryl(-SH) concentration, and a significant increase of lipid peroxidation measued as malondialdhyde (MDA) in the liver tissues. Administration of different doses of the TQ (4, 8, 12.5, 25 and 50 mg/Kg i.p.) did not alter the chosen biochemical parameters measured, while higher doses of TQ were lethal. The LD50 was 90.3 mg/Kg (77.9-104.7, 95% CL). Pretreatment of mice with different doses of TQ 1 h before CCl4 injection showed that the only dose of TQ that ameliorated hepatotoxicity of CCl4 was 12.5 mg/Kg i.p. as evidenced by the significant reduction of the elevated levels of serum enzymes as well as hepatic MDA content and significant increase of the hepatic nonprotein sulfhydryl(-SH) concentration. Treatment of mice with the other volatile oil constituents, p-cymene or alpha-pinene did not induce any changes in the serum ALT measured. In addition, i.p. administration of these compounds 1 h before CCl4 injection, did not protect mice against CC4-induced hepatotoxicity. The results of the present study indicate that TQ (12.5 mg/Kg, i.p.) may play an important role as antioxidant and may efficiently act as a protective agent against chemically-induced hepatic damage. In contrast, higher doses of TQ were found to induce oxidative stress leading to hepatic injury.

Disease progression in periodontally treated and untreated patients--a retrospective study.

BACKGROUND, AIMS: The aim of this retrospective study was to assess the effect of regular supportive periodontal treatment on disease progression in patients with moderate to advanced periodontitis. METHOD: We compared radiographic change of interdental bone level and number of teeth at 2 time points in 3 patient groups (mean age 46 years): group A, periodontally untreated patients (n= 14) who dropped out during initial therapy; group B, non-compliant patients (n=26), who discontinued supportive periodontal therapy after ca. 2 years of maintenance; group C, compliant patients (n=27), who regularly attended the maintenance program for 7 years. Periodontal treatment was performed as scaling and root planing or flap surgery in groups B and C. All 3 groups were re-examined ca. 7 years after the initial examination. RESULTS: Patients in group A lost 3.8 teeth (0.5 teeth/year), those in group B 3.2 (0.4 teeth/year), and in group C, patients lost 2.0 teeth (0.2 teeth/year). About half of the patients lost no teeth (group A 43%, B 42%, C 55%), and only 17 subjects lost more than 3. At the 2nd examination, an increase in interdental bone was found only in group C (+0.13 mm), while groups A and B lost 0.57 mm and 0.31 mm of alveolar bone level, respectively (p<0.05 group C versus A and B). CONCLUSIONS: Systematic periodontal treatment stops interdental bone loss and decreases the rate of tooth loss in most cases. Periodontal surgery without regular follow-up care cannot prevent further periodontal destruction, but it can delay it.

Polymorphism of the N-acetyltransferase (NAT2), smoking and the potential risk of periodontal disease.

Periodontal disease is a common multifactorial process that leads to bone destruction and tooth loss. Interactions of environmental and genetic factors determine the extent and severity of periodontal disease. Smoking is one of the risk factors for periodontal disease, and the risk may be influenced by the polymorphism of N-acetyltransferase (NAT2) via metabolism of smoke-derived xenobiotics. We therefore hypothesized that a NAT2 genotype would be a risk factor for periodontal disease. A total of 154 Caucasian subjects were assigned to one of two groups (1) no or mild and (2) severe periodontal disease based on radiographic (bone destruction) and clinical criteria (probing depth, attachment loss) and the number of teeth. In all subjects genotyping for mutations on NAT2 was performed by means of PCR and RFLP analysis. In the less-affected group genotyping showed a fraction of predicted slow and rapid acetylators (53.6% and 46.4%, respectively) corresponding to the normal distribution in Caucasians. Severely affected patients were predominantly slow acetylators, the odds ratios being between 2.38 and 5.02 for the NAT2-related risk depending on the outcome parameters chosen. Adjustment for age had no influence on these findings. Our data indicate that the slow acetylator phenotype is associated with a higher risk of periodontitis, especially with respect to the severity of the disease. Possible implications with respect to the risk associated with smoking are discussed.

Resolution of interdental inflammation with 2 different modes of plaque control.

BACKGROUND, AIMS: The aim of the study was to assess the effect on existing plaque and gingivitis of an oral hygiene regimen which utilizes triclosan/copolymer and to compare it with a regimen which uses interdental cleaning devices to control the interdental inflammation. METHOD: For this investigation, 39 subjects were recruited. They were examined for plaque and gingivitis using the criteria of Turesky modification of the Quigley-Hein index and the papillary bleeding index. Plaque and gingivitis were only scored interdentally. Following the baseline examination, the subjects were randomly assigned into 2 groups. The control group used a dentifrice identical to the test dentifrice but without triclosan/copolymer; subjects in this group were taught to brush their teeth with the modified Bass technique and were instructed to additionally use appropriate interdental cleaning devices. The test group used a dentifrice containing triclosan/copolymer (Colgate Total). They were not instructed to use interdental cleaning devices. RESULTS: Both groups were re-examined after 4 weeks, and 4 and 7 months. In both groups, plaque and gingivitis levels were modestly reduced, more pronounced in the anterior and less in the posterior teeth. CONCLUSIONS: This investigation demonstrated that a dentifrice containing triclosan in combination with a copolymer can reduce plaque and gingival inflammation to levels comparable to regular interdental cleaning.

Thymoquinone protects against carbon tetrachloride hepatotoxicity in mice via an antioxidant mechanism.

Thymoquinone (TQ) is the major active component of the volatile oil of Nigella sativa seeds. The effects of TQ on carbon tetrachloride (CCl4)-induced hepatotoxicity was investigated in male Swiss albino mice. Carbon tetrachloride (20 microliters/Kg, i.p.) injected into mice, induced damage to liver cells and was followed by the increase in serum alanine aminotransferase (ALT) activity after 24 h. Oral administration of TQ in a single dose (100 mg/Kg) resulted in significant (p < 0.001) protection against the hepatotoxic effects of CCl4. TQ was tested as a substrate for mice hepatic DT-diaphorase in the presence of NADH. TQ appears to undergo reduction to dihydrothymoquinone (DHTQ). Reduction rates as a function of protein (liver homogenate) and substrate (TQ) concentrations are reported. An apparent K(m) of 0.1 mM and an apparent Vmax of 74 mumol/min/g liver were measured. TQ and DHTQ inhibited the in vitro non-enzymatic lipid peroxidation in liver homogenate (induced by Fe(3+)-ascorbate) in a dose dependent manner. In this in vitro model DHTQ was more potent in comparison with TQ and butylated hydroxytoluene (BHT). The IC50 for DHTQ, TQ and BHT were found to be 0.34, 0.87 and 0.58 microM respectively. The data suggest that the in vivo protective action of TQ against CCl4-induced hepatotoxicity may be mediated through the combined antioxidant properties of TQ and its metabolite DHTQ.

Cytokeratin alterations as diagnostic and prognostic markers of oral and pharyngeal carcinomas. A prospective study.

Cytokeratin (CK) alterations have been reported in carcinomas from different anatomical sites, and these have been associated with specific aspects of tumour behaviour. In order to assess the relationships between CK modifications and future tumour behaviour, we conducted the present prospective study on 26 squamous cell carcinomas (SCC) of oral and pharyngeal mucosae and corresponding controls. Cytokeratins were investigated using two-dimensional gel electrophoresis and immunofluorescence techniques. All healthy tissues, oral lining and oropharyngeal mucosae, expressed the oesophageal type CKs, including CK 19. Other simple epithelial CKs (7, 8, 17 and 18) were not detected. In carcinomas originating from corresponding sites, expression of oesophageal CKs varied widely from one specimen to another, and simple epithelial keratins were often found. Statistical analysis indicated correlations between CK expression and the clinicopathological data of SCC patients. Small tumour size was strongly associated with the expression of CKs 10 and 19. Interestingly, an absence of lymph node involvement was significantly associated with CK 18 expression. Tumours giving rise to recurrences, metachronous tumours, and distant metastasis were significantly associated with an absence of CK 13. These results suggest that CKs 10, 19, 18 and 13 could be reliable diagnostic and prognostic markers in the assessment of oral and pharyngeal squamous carcinomas.

Effects of L-histidinol on the antitumour activity and acute cardiotoxicity of doxorubicin in mice.

L-Histidinol (LHL), a structural analogue of the essential amino acid l-histidine, can improve the therapeutic index of antimetabolites and alkylating agents. The objective of the study was to determine whether LHL would modulate the antitumour activity and acute cardiotoxicity of the anthracycline antibiotic, doxorubicin (DOX). LHL (1.0 mM) potentiated the cytotoxicity of DOX (0.05-0.8 microg ml-1) in cultured Ehrlich ascites carcinoma (EAC) cells. LHL (250 mg kg-1, i.p.) administered for five consecutive doses at 2-h intervals starting 2 h before DOX (5 mg kg-1, i.p.) single injection, enhanced the antitumour activity of DOX in EAC-bearing mice as manifested by a significant increase in average life span and cure rate of mice. In normal mice, LHL, in the same dose regimen, could not alter the acute cardiotoxicity and lethality of DOX (10 mg kg-1, i.p.). The present data indicate that LHL may improve the therapeutic efficacy of DOX in EAC-bearing mice without compromising its toxicity. Also, our finding supports the LHL/anticancer drug combination approach.

Constitutional balanced translocations in alveolar rhabdomyosarcoma.

Chromosomal analysis of tumor tissue from two children with alveolar rhabdomyosarcoma revealed t(1;5)(q32;q31) and t(1;22)(q21;q11.2) in all metaphases examined, respectively. Peripheral blood lymphocytes carried the same cytogenetic abnormality as that of the tumor cells in both patients. Parental lymphocytes were karyotypically normal in the patient with t(1;22), indicating a de novo constitutional translocation, but t(1;5) was paternally inherited in the other patient. The presence of constitutional translocations in these two children might have contributed to the development of alveolar rhabdomyosarcoma.

Vitamin E protects the brain against oxidative injury stimulated by excessive aluminum intake.

The effect of feeding groups of mice with a diet containing 2000, 4000 and 6000 micrograms aluminum (Al3-/g) for two weeks (subacute) or 2000 and 4000 micrograms Al3+/g for eight weeks (subchronic) as well as the coadministration of vitamin E (alpha-tocopherol) 500 micrograms/g with Al3+, on the status of glutathione (GSH) and lipid peroxides as thiobarbituric acid reactive substances (TBARS) in whole brain tissues were evaluated. Changes in TBARS were further evaluated in vitro following the incubation of brain homogenates of the Al(3+)-fed mice in the presence of 50 microM FeSO4. The results of subacute experiments revealed that the brain levels of GSH were significantly decreased only in the group of mice that received 6000 micrograms Al3+/g diet (P < 0.05) and this effect was partially ameliorated when vitamin E was coadministered with Al3+. TBARS were significantly increased in vitro only in the presence of free iron ions and depended on the concentration of Al3+ in the diet. The effect was opposed by the vitamin E intake. Following subchronic Al3+ intake, the GSH content of the brain was significantly decreased only in the group of mice that received 4000 micrograms Al3+/g diet (P < 0.01), while TBARS were significantly increased in the brain tissues in vivo as well as in the presence of free iron ions in vitro. However, coadministration of vitamin E with Al3+ for eight weeks preserved GSH levels and decreased TBARS in the brain of mice in vivo and in the presence of free iron ions in vitro. It is concluded that the long term administration of vitamin E may prevent Al3(+)-stimulated oxidative injury in the brain.

Effect of L-histidinol on cisplatin nephrotoxicity in the rat.

The effect of L-histidinol (LHL) on the acute nephrotoxicity produced by cisplatin (CDDP; 6 mg/kg, i.v.) was investigated in the rat. Intraperitoneal administration of LHL (100 mg/kg x 5 doses, 2 h apart) starting 2 h prior to CDDP single injection produced significant protection of renal function. The attenuation of nephrotoxicity was evidenced by significant reductions in serum urea and creatinine concentrations, decreased polyuria, reduction in body weight loss, marked reduction in urinary fractional sodium excretion and glutathione-S-transferase (GST) activity, and increased urine/serum creatinine ratio as well as increased creatinine clearance. LHL significantly ameliorated the toxic renal biochemical changes induced by CDDP. Renal lipid peroxides, glutathione levels and GST activity showed a marked tendency towards the normal values. Accumulation of platinum in renal tissues was significantly decreased in the presence of LHL. It is concluded that LHL can act as a nephroprotectant, and it is suggested that it would have beneficial effects on the kidney in clinical settings.

Thymoquinone ameliorates the nephrotoxicity induced by cisplatin in rodents and potentiates its antitumor activity.

The effects of thymoquinone (TQ) on cisplatin-induced nephrotoxicity in mice and rats were studied. Oral administration of TQ (50 mg/L in drinking water) for 5 days before and 5 days after single injections of cisplatin (5 mg/kg, i.v., in rats and 7 or 14 mg/kg, i.p., in mice) greatly ameliorated cisplatin-induced nephrotoxicity in both species. In rats, i.v. cisplatin caused 4- and 5-fold elevations in serum urea and creatinine, a 235% increase in urine volume, a 41% increase in kidney weight, 8.5-fold decrease in creatinine clearance, and extensive histological damage 5 days after treatment. In mice, similar alterations in kidney function were observed. TQ-induced amelioration of cisplatin nephrotoxicity was evident by significant reductions in serum urea and creatinine and significant improvement in polyuria, kidney weight, and creatinine clearance. The protective effects of TQ against cisplatin-induced nephrotoxicity in the rat were further confirmed by histopathological examination. To evaluate the possible modification of the antitumor activity of cisplatin by TQ, we studied their interaction in Ehrlich ascites carcinoma (EAC) bearing mice. The results revealed that TQ potentiated the antitumor activity of cisplatin. The current study suggests that TQ may improve the therapeutic index of cisplatin.

Vitamin E protects against bacterial endotoxin-induced increase of plasma corticosterone and brain glutamate in the rat.

Plasma corticosterone (CS) and brain free aminoacids were determined in male rats 2 hr after acute exposure to bacterial endotoxin stress BES (2.0 mg/kg i.p. of lipopolysaccharide, LPS). A significant increase in the levels of plasma CS and brain taurine (Tau), aspartate (As), glutamate (Glu), glycine (Gly) and valine (Val) was observed following BES. When vitamin E (alpha-tocopherol acetate AT) was given orally (0.25 gm/kg/day) 4 days before induction of BES, the plasma CS as well as the brain Glu levels were significantly reduced to the control values. These results indicate that plasma CS and brain Glu may be involved in the mechanisms by which AT protects against the neurotoxicity of BES.

Spectrophotometric assay for superoxide dismutase based on the nitroblue tetrazolium reduction by glucose-glucose oxidase.

A new spectrophotometric assay of superoxide dismutase (SOD) is described. The assay is based on the SOD-mediated inhibition in the rate of nitroblue tetrazolium reduction to the blue formazan at alkaline pH. The optimized assay of SOD is performed in 50 mM glycine-NaOH buffer, pH 9.5, at 25 degrees C. The SOD concentration is determined from the V/v ratio of rates measured in the absence (V) or the presence (v) of SOD. One unit of SOD has been defined as the concentration that decrease the rate to 50% (V/v = 2). The assay is simple, sensitive, uses commercially available reagents, rapid and easy to perform and could be used routinely for monitoring superoxide dismutase levels in purified protein fractions.