High levels of NRF2 sensitize temozolomide-resistant glioblastoma cells to ferroptosis via ABCC1/MRP1 upregulation.

Glioblastoma patients have a poor prognosis mainly due to temozolomide (TMZ) resistance. NRF2 is an important transcript factor involved in chemotherapy resistance due to its protective role in the transcription of genes involved in cellular detoxification and prevention of cell death processes, such as ferroptosis. However, the relation between NRF2 and iron-dependent cell death in glioma is still poorly understood. Therefore, in this study, we analyzed the role of NRF2 in ferroptosis modulation in glioblastoma cells. Two human glioblastoma cell lines (U251MG and T98G) were examined after treatment with TMZ, ferroptosis inducers (Erastin, RSL3), and ferroptosis inhibitor (Ferrostatin-1). Our results demonstrated that T98G was more resistant to chemotherapy compared to U251MG and showed elevated levels of NRF2 expression. Interestingly, T98G revealed higher sensitivity to ferroptosis, and significant GSH depletion upon system xc- blockage. NRF2 silencing in T98G cells (T98G-shNRF2) significantly reduced the viability upon TMZ treatment. On the other hand, T98G-shNRF2 was resistant to ferroptosis and reverted intracellular GSH levels, indicating that NRF2 plays a key role in ferroptosis induction through GSH modulation. Moreover, silencing of ABCC1, a well-known NRF2 target that diminishes GSH levels, has demonstrated a similar collateral sensitivity. T98G-siABCC1 cells were more sensitive to TMZ and resistant to Erastin. Furthermore, we found that NRF2 positively correlates with ABCC1 expression in tumor tissues of glioma patients, which can be associated with tumor aggressiveness, drug resistance, and poor overall survival. Altogether, our data indicate that high levels of NRF2 result in collateral sensitivity on glioblastoma via the expression of its pro-ferroptotic target ABCC1, which contributes to GSH depletion when the system xc- is blocked by Erastin. Thus, ferroptosis induction could be an important therapeutic strategy to reverse drug resistance in gliomas with high NRF2 and ABCC1 expression.

Estrogen receptor alpha gene ( ESR1) polymorphism can contribute to clinical findings in systemic lupus erythematosus patients.

Background Estrogens have a modulatory effect on several immune responses, many of which are correlated to autoimmune diseases. Estrogens act through binding to their receptors, and an overexpression of these receptors has been identified in patients with different autoimmune diseases. Here we analyzed the association of a putative functional genetic variant in the main estrogen receptor (ERα) gene ( ESR1), and the susceptibility to clinical findings and severity of SLE. Methods A total of 426 individuals (266 healthy controls and 160 SLE patients) were genotyped for the polymorphism rs2234693 in the ESR1 gene. Allele and genotype frequencies were calculated and analyzed between cases and controls using Unphased software. Results The SNP rs2234693 was not associated with SLE per se but the minor allele rs2234693-C was correlated with the presence of nephritis and discoid skin rash. On the other hand, the rs2234693-CC genotype was correlated with the absence of arthritis as well as anti-ANA and anti-RNP autoantibodies. The comprehensive clinical analysis of these patients revealed a more severe status of the disease, characterized by a younger age of onset and higher number of organs involved when compared to European populations. Conclusions Minor allele rs2234693-C was associated with renal and cutaneous involvement, as well as the absence of arthritis, anti-ANA and anti-RNP autoantibodies.

Functional polymorphisms of interleukin-18 gene and risk of breast cancer in a Brazilian population.

Interleukin-18 (IL-18) is a key cytokine responsible for immune response and involved in the process of cancer development. In this case-control study, we tested whether IL-18 promoter polymorphism contributes to breast cancer susceptibility in Brazilian patients. The two groups studied were 154 patients with breast cancer and 118 healthy individuals. The frequency of IL-18 promoter single nucleotide polymorphisms (SNPs) at positions -607 (C/A) (rs1946518) and -137 (G/C) (rs187238) was determined by polymerase chain reaction analyses. The polymorphisms genotyped in this study showed a significant association with breast cancer under different genetic models. Both SNPs showed a positive association. For the IL18-607 polymorphism the best model was the codominant genetic model [CC vs AA, P = 0.004, odds ratio (OR) = 2.782, 95% confidence interval (CI) 1.385-5.589]. For IL18-137 statistical significance was found using the recessive genetic model (P = 0.008, OR = 3.896, 95% CI 1.427-10.639). The association between the haplotypes of the IL18 gene and breast cancer was further confirmed. Our results suggest that IL18-607 and IL18-137 polymorphism contributes to increase the breast cancer risk. To our knowledge, this is the first report regarding Brazilian breast cancer patients and IL18 promoter polymorphisms.

Neonatal morphine administration leads to changes in hippocampal BDNF levels and antioxidant enzyme activity in the adult life of rats.

It is know that repeated exposure to opiates impairs spatial learning and memory and that the hippocampus has important neuromodulatory effects after drug exposure and withdrawal symptoms. Thus, the aim of this investigation was to assess hippocampal levels of BDNF, oxidative stress markers associated with cell viability, and TNF-α in the short, medium and long term after repeated morphine treatment in early life. Newborn male Wistar rats received subcutaneous injections of morphine (morphine group) or saline (control group), 5 µg in the mid-scapular area, starting on postnatal day 8 (P8), once daily for 7 days, and neurochemical parameters were assessed in the hippocampus on postnatal days 16 (P16), 30 (P30), and 60 (P60). For the first time, we observed that morphine treatment in early life modulates BDNF levels in the medium and long term and also modulates superoxide dismutase activity in the long term. In addition, it was observed effect of treatment and age in TNF-α levels, and no effects in lactate dehydrogenase levels, or cell viability. These findings show that repeated morphine treatment in the neonatal period can lead to long-lasting neurochemical changes in the hippocampus of male rats, and indicate the importance of cellular and intracellular adaptations in the hippocampus after early-life opioid exposure to tolerance, withdrawal and addiction.

Ectophosphatase activity in Candida albicans influences fungal adhesion: study between HIV-positive and HIV-negative isolates.

OBJECTIVE: This study describes the expression of acidic ectophosphatase activity on twenty isolates of C. albicans from oral cavities of HIV-infected children (HIV+) and compares them with fifteen isolates from HIV-negative children (HIV-), as well as the fungal adhesion to epithelial cells and medical records. METHODS: The activities were measured in intact cells grown in BHI medium for 48 h at 37 degrees C. Phosphatase activity was assayed at pH 5.5 using 4-methylumbelliferyl phosphate. Yeast adhesion was measured using the MA 104 epithelial cell line. RESULTS: Mean values of ectophosphatase activity were 610.27 +/- 166.36 and 241.25 +/- 78.96 picomoles 4-methylumbelliferone/h/10(7) cells for HIV+ and HIV- group, respectively (P = 0.049). No correlation between C. albicans enzyme activity from HIV children with viral load and CD4 percentual was observed. Yeasts with high enzyme activity, isolated from HIV+ children showed greater adherence than yeasts with basal levels of ectophosphatases from HIV- (Spearman correlation, r = 0.8). Surface phosphatase activity was apparently involved in the adhesion to host cells, as the enhanced attachment of C. albicans to host epithelial cells was reversed by pretreatment of yeast with sodium orthovanadate (1 mM), an acid phosphatase inhibitor. CONCLUSION: These results show that C. albicans from HIV+ has an ectophosphatase activity significantly higher than the other isolates. Yeasts expressing higher levels of surface phosphatase activity showed greater adhesion to epithelial cells. So, the activity of acidic surface phosphatases on these cells may contribute to the early mechanisms required for disease establishment.

Synthesis and antitumour activity of the Primin (2-methoxy-6-n-pentyl-1,4-benzoquinone) and analogues.

Cancer is a serious worldwide health threat, killing almost seven million people per year. Quinones are an important class of antitumour agents that are activated by tumour hypoxia. Primin (2-methoxy-6-n-pentyl-1,4-benzo-quinone), a naturally-occurring product obtained from Primula obconica (Primulaceae) has shown antimicrobial and antitumour properties. The synthesis of the Primin to obtain 3-, 5- or 6-alkyl substituted derivatives has been previously attempted seeking antitumour activity. The intermediate reaction products, 2-methoxy-hydroquinone-di-(2'-tetrahydro-pyranyl) ether and 2-methoxy-6-n-pentyl-hydroquinone-di-(2'-tetrahydropyranyl) ether were obtained and evaluated against sarcoma 180 (S-180) and Ehrlich carcinoma, as well as toxicity tests were performed. The antitumour activity tests showed that these intermediate compounds were able to inhibit S-180 sarcoma and Ehrlich carcinoma growth in mice. These results indicated that the tetrahydropyranyl protect group conserved the antitumour activity in comparison with quinone group, however, it exhibited a less toxic effect, with no characteristic of quinones. These results can suggest that compound 2-methoxy-6-n-pentyl-hydroquinone-di-(2'-tetrahydropyranyl) ether may act as a prodrug with some advantages in comparison with the Primin.

Oral manifestations related to immunosuppression degree in HIV-positive children.

Oral manifestations often found in HIV-infected children are frequently the first clinical sign of the infection. This article aims to report the prevalence of oral manifestations in soft tissues and their relationship with the degree of immunosuppression in 80 HIV-infected patients (average age 6.30 +/- 3.32 years old) at the IPPMG-UFRJ. Thirty children (38%) presented some type of oral lesion and the percentage of CD4 was lower than that found in lesion-free children (p < 0.05); 22.5% presented candidiasis, 17.5% gingivitis, 8.8% enlargement of parotids, 1.3% herpes simplex and 1.3% hairy leukoplakia. Of the 30 children with lesions, 70% showed severe immunosuppression, 23.3% moderate immunosuppression and in only 6.7% was immunosuppression absent. Oral manifestations were directly related to the degree of immunosuppression and such lesions can be considered as indicators of the progression of the HIV infection in children.

Influence of temperature and humidity on laser in situ keratomileusis outcomes.

PURPOSE: The influence of ambient factors on the results of refractive surgery is not well-known. This study evaluated the influence of temperature and humidity on laser in situ keratomileusis (LASIK) outcomes. METHODS: Two hundred thirty-seven patients who underwent LASIK at the Clivan Instituto de Oftalmologia in Salvador--Bahia--Brazil, between May 1999 and March 2000, were evaluated. A total of 156 (65.8%) patients were female. Mean age was 30.3 +/- 7.6 years. Refractive errors: 197 patients (83.12%) had compound myopic astigmatism, 17 patients (7.17%) had myopia, 11 patients (4.64%) had compound hyperopic astigmatism, and 12 patients (5.07%) had other. Results at 15 and 60 days after LASIK were compared according to different levels of temperature and humidity in the operating room during the procedure. RESULTS: Patients whose spherical equivalent refraction varied between -0.50 to +0.50 D at 15 days after LASIK had surgery performed when the temperature was 25.1 +/- 1.4 degrees C and humidity was 45.1 +/- 4.2%; for the others, temperature was 24.7 +/- 1.5 degrees C (P = .12) and humidity was 43.0 +/- 4.0% (P = .002). The linear regression coefficient showed that lower temperature levels were associated with lower spherical equivalent refractions at 60 days after LASIK (r2 = .14; P = .03) but not at 15 days after LASIK (P = .98). The evaluation of humidity indicated an influence at 15 days after LASIK (r2 = .44; P = .04), as well as at 60 days (r2 = .45; P = .0002). CONCLUSION: Operating room environment may influence LASIK outcomes; humidity may be more significant than temperature.

Craniometaphyseal dysplasia: case report.

Craniometaphyseal dysplasia is a rare genetic bone remodeling disorder characterized by undertubulation of the long bones, especially in the lower extremities, causing deformities of the metaphyses of the long bones, and sclerosis of the skull base or cranial bone hyperostosis. The authors report a case of craniometaphyseal dysplasia in an 8-year-old Brazilian child, emphasizing the importance of precocious diagnosis of this rare genetic disorder.

[Intra-operative identification of the ostium of Wirsung's pancreatic duct after papillosphincterotomy]. / Identificação trans-operatória do óstio do Wirsung após a papilo-esfincterotomia.

PURPOSE: The aim of this study is to suggest a feasible method to find the ostium of the Wirsung's duct during sphincteroplasty of the Vater's papilla, in order to avoid post-operative complications such as acute pancreatitis. PATIENTS AND METHODS: A total of 27 patients were submitted to sphincteroplasty for choledocolithiasis with or without Odditis. After therapeutic papillotomy and sphincterotomy through the duodenun, the location of the ostium of the Wirsung's duct was determined and studied. After papillotomy, the Vater's papilla becomes an isosceles triangle and its measurements were made with a compass. Thereby the ostium of Wirsung's duct was easily detected and a catheter was inserted before the suture of the mucosa of the papilla. RESULTS: The ostium was generally found medially, on the left side of the triangle, 0.19 cm to 0.25 cm on average above its base whether there was inflammation or not, respectively. CONCLUSION: The transoperative determination of the dimensions as proposed in this study, allows a safety detection and cannulation of the Wirsung's duct with or without inflammation of the Oddi's sphincter.

NMDA receptor blockade attenuates the haloperidol induction of Fos protein in the dorsal but not the ventral striatum.

Neuroleptic blockade of dopamine receptors is known to produce an increase in the expression of Fos. This increase may be related to elevations in glutamate transmission which in turn activates N-methyl-D-aspartate (NMDA) receptors. In the present study, we examine the role of these receptors in the haloperidol-induced augmentation of Fos in the caudate-putamen and nucleus accumbens of Wistar rats. Animals were divided into four groups for each experiment and each was injected either with saline; a noncompetitive NMDA antagonist, dizocilpine maleate (MK801, 5 mg/kg); haloperidol (0.5 mg/kg); or MK801 followed by an injection of haloperidol. Fos-immunoreactive cells appear in large numbers in all parts of the striatum 3 h after the administration of haloperidol. Pretreatment with MK801 attenuates the haloperidol-induced increase in Fos in the caudate-putamen. However, antagonism of the NMDA receptor does not significantly reduce the density of Fos-immunoreactive cells in any territory of nucleus accumbens, i.e., shell, core, or rostral pole. These data suggest that haloperidol acts in an NMDA-dependent manner in the caudate-putamen, but independently in parts of nucleus accumbens traditionally considered to be targets of antipsychotic drugs.

[Utility of gamma rays in prophylaxis of transmissible malaria by blood transfusion]. / Estudo sobre a eventual utilidade de raios gama na profilaxia da malária transmissível por transfusão de sangue.

This study was carried out to evaluate the fortuitons advantage of using gamma irradiation in the prophylaxis of transmissible malaria by blood transfusion, with mice as the experimental model. In the first step, when the infected blood with Plasmodium berghei was submitted to 2,500 rad and 5,000 rad, with or without metronidazol, there was no success, because the animals presented parasitaemia and died after inoculation of irradiated blood. However, there was partial success in the second step, when the infected blood received 10,000 and 15,000 rad, and was inoculated in mice, which showed infection, and presented a survival rate of 20% and 40%, respectively, with later negativation of blood infected by P. berghei.

Automated determination of tin and nickel in brass by on-line anodic electrodissolution and electrothermal atomic absorption spectrometry.

The application of an on-line metallic alloy dissolution system using anodic electrodissolution in a flow injection system for the determination of tin and nickel in copper alloys is described. After the electrolyzed material was collected in the autosampler cup, determination was carried out using electrothermal atomic absorption spectrometry (ETAAS). Using specific software developed in Turbo Pascal 7.0, it is possible to control electrolysis time, intensity of the applied current, and triggering of the three-way solenoid valves that push the fluids. Through manipulation of these variables, it is possible to adjust the analytical signal to within the working range of the spectrometer. Calibration of the spectrometer was accomplished by processing reference material. For tin, relative standard deviations for a series of measurements (n=5) performed on the same point and on different points of the sample was smaller than 2 and 4%, respectively; for nickel, 2 and 5%, respectively. The results for tin and nickel were in good agreement with those obtained through application of the classical methodology, as well as with data obtained by optical emission spectrometry. The detection limit for tin was 0.001% (w/w), whereas for nickel it was 0.003% (w/w). The analytical throughput is 30 samples h(-1).