Radiation metabolomics. 4. UPLC-ESI-QTOFMS-Based metabolomics for urinary biomarker discovery in gamma-irradiated rats

Radiation metabolomics has aided in the identification of a number of biomarkers in cells and mice by ultra-performance liquid chromatography-coupled time-of-flight mass spectrometry (UPLC-ESI-QTOFMS) and in rats by gas chromatography-coupled mass spectrometry (GCMS). These markers have been shown to be both dose- and time-dependent. Here UPLC-ESI-QTOFMS was used to analyze rat urine samples taken from 12 rats over 7 days; they were either sham-irradiated or γ-irradiated with 3 Gy after 4 days of metabolic cage acclimatization. Using multivariate data analysis, nine urinary biomarkers of γ radiation in rats were identified, including a novel mammalian metabolite, N-acetyltaurine. These upregulated urinary biomarkers were confirmed through tandem mass spectrometry and comparisons with authentic standards. They include thymidine, 2'-deoxyuridine, 2'deoxyxanthosine, N(1)-acetylspermidine, N-acetylglucosamine/galactosamine-6-sulfate, N-acetyltaurine, N-hexanoylglycine, taurine and, tentatively, isethionic acid. Of these metabolites, 2'-deoxyuridine and thymidine were previously identified in the rat by GCMS (observed as uridine and thymine) and in the mouse by UPLC-ESI-QTOFMS. 2'Deoxyxanthosine, taurine and N-hexanoylglycine were also seen in the mouse by UPLC-ESI-QTOFMS. These are now unequivocal cross-species biomarkers for ionizing radiation exposure. Downregulated biomarkers were shown to be related to food deprivation and starvation mechanisms. The UPLC-ESI-QTOFMS approach has aided in the advance for finding common biomarkers of ionizing radiation exposure.     

The behavior of normal peripheral nerve in Tissue culture

Summary A phase contrast and time lapse cinematographic study of normal mouse sciatic nerve cultured in vitro was made. The Rose chamber and chicken plasma clot methods were employed. The growth was characterized by three basic cell types: a spindle-shaped cell with a bulging nucleus, a racket-shaped cell with a short wide fan-shaped process and an opposite filiform process, and a kite-shaped cell with abundant ectoplasm. The spindle-shaped cells exhibited a pulsatile rhythmic activity. The rhythm of contraction varied from two to eighteen minutes. No contractile activity was observed in the case of the racket-shaped cells nor in the kite-shaped cells. The spindle-shaped cells were thought to be Schwann cells, the kite-shaped cells were considered of a fibroblastic nature, whereas no source could be found for the racket-shaped cells, although the perineurium was considered as a possible origin. The cultures were maintained up to 80 days, but at no time were phagocytes, observed. With the methods employed no transformation of cells from one type to another took place, and the Schwann cells did not transform themselves into phagocytes.This work was supported in part by grant P-405A from the American Cancer Society and by NIH grant NB-06391-02.     

Behavioral characterization of striatal‐enriched protein tyrosine phosphatase (STEP) knockout mice

Striatal‐enriched protein tyrosine phosphatase (STEP) has been described as a regulator of multiple kinases and glutamate receptor subunits critical for synaptic plasticity. Published behavioral and biochemical characterization from the founder line of STEP knockout (KO) mice revealed superior cognitive performance, with enhanced phosphorylation of substrates such as ERK, Fyn and GluN2B; suggesting that inhibitors of STEP may have potential as therapeutic agents for the treatment of neuropsychiatric disorders. The objectives of this work aimed to replicate and extend the previously reported behavioral consequences of STEP knockout. Consistent with previous reported data, STEP KO mice demonstrated exploratory activity levels and similar motor coordination relative to WT littermate controls as well as intact memory in a Y‐maze spatial novelty test. Interestingly, KO mice demonstrated deficits in pre‐pulse inhibition as well as reduced seizure threshold relative to WT controls. Immunohistochemical staining of brains revealed the expected gene‐dependent reduction in STEP protein confirming knockout in the mice. The present data confirm expression and localization of STEP and the absence in KO mice, and describe functional downstream implications of reducing STEP levels in vivo.     

Caloric restriction increases free radicals and inducible nitric oxide synthase expression in mice infected with Salmonella Typhimurium

It is well known that CR (caloric restriction) reduces oxidative damage to proteins, lipids and DNA, although the underlying mechanism is unclear. However, information concerning the effect of CR on the host response to infection is sparse. In this study, 6-month-old mice that were fed AL (ad libitum) or with a CR diet were infected with Salmonella serovar Typhimurium. EPR (electron paramagnetic resonance; also known as ESR (electron spin resonance)) was used to identify FRs (free radicals). These results were subsequently correlated with SOD (superoxide dismutase) catalytic activity, iNOS [inducible NOS (nitric oxide synthase) or NOSII] expression and NO (nitric oxide) content. EPR analysis of liver samples demonstrated that there was a higher quantity of FRs and iron-nitrosyl complex in infected mice provided with a CR diet as compared with those on an AL diet, indicating that CR was beneficial by increasing the host response to Salmonella Typhimurium. Furthermore, in infected mice on the CR diet, NOSII expression was higher, NO content was greater and spleen colonization was lower, compared with mice on the AL diet. No changes in SOD activity were detected, indicating that the NO produced participated more in the formation of iron-nitrosyl complexes than peroxynitrite. These results suggest that CR exerts a protective effect against Salmonella Typhimurium infection by increasing NO production.     

Substrate specificity of the phenolic acid decarboxylase from Lactobacillus plantarum and related bacteria analyzed by molecular dynamics and docking

Journal of Plant Biochemistry and Biotechnology - The phenolic acid decarboxylase (PAD) is a 44 kDa homodimeric, thermolabile and acid-resistant enzyme that some bacteria have developed as...     

Historical Analysis of the Brazilian Cervical Cancer Screening Program from 2006 to 2013: A Time for Reflection

Background

The Cervical Cancer Database of the Brazilian National Health Service (SISCOLO) contains information regarding all cervical cytological tests and, if properly explored, can be used as a tool for monitoring and managing the cervical cancer screening program. The aim of this study was to perform a historical analysis of the cervical cancer screening program in Brazil from 2006 to 2013.

Material and Methods

The data necessary to calculate quality indicators were obtained from the SISCOLO, a Brazilian health system tool. Joinpoint analysis was used to calculate the annual percentage change.

Results

We observed important trends showing decreased rates of low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL) and an increased rate of rejected exams from 2009 to 2013. The index of positivity was maintained at levels below those indicated by international standards; very low frequencies of unsatisfactory cases were observed over the study period, which partially contradicts the low rate of positive cases. The number of positive cytological diagnoses was below that expected, considering that developed countries with low frequencies of cervical cancer detect more lesions annually.

Conclusions

The evolution of indicators from 2006 to 2013 suggests that actions must be taken to improve the effectiveness of cervical cancer control in Brazil.     

Membrane-initiated steroid signaling (MISS): genomic steroid action starts at the plasma membrane

Plasma membrane (PM) steroid recognition sites are thought to be responsible only for rapid, non-genomic responses without any link to the nuclear receptor-mediated genomic effects of steroids. We focused on a PM "glucocorticoid-importer" (GC-importer) that imports GC into rat liver cells. This site interacts also with particular gestagens (progesterone, P; medroxyprogesterone, MP; ethynodiol, Ethy) and estrogens (ethinylestradiol, EE(2); mestranol), which do not bind to the nuclear GC receptor (GR). To elucidate the role of the GC-importer, we transfected a rat wild-type hepatocyte (CC-1) and a hepatoma cell line, unable to import GC (MH 3924), with a GC<-->GR-responsive luciferase (luc)-reporter gene. Selected steroids were tested for their ability to induce or inhibit luc expression. Corticosterone (B) and dexamethasone (Dex), but also the GC-antagonists cortexolone (Cortex), P and MP, induced luc. Even the PM-impermeable BSA-derivatives of B, Dex and Cortex did so to almost the same extent as the free steroids. MH 3924 cells respond stronger than CC-1 to luc inducing steroids. Luc expression was inhibited by RU 38 486, but also by EE(2) and Ethy. The thiol reactive mesylate-derivatives of B, Dex and Cortex induced to a considerably lesser extent than the free or BSA-steroids. The thiol reagent mersalyl blocks cellular entry of GC and inhibits luc induction in CC-1 cells. Incubation with EE(2) and B of PM-vesicles, isolated from liver cells, resulted in a decrease of the density of two 75 and 52kDa G-proteins reflecting a diminished exchange of GDP by GTP. CONCLUSION: the PM-residing GC-importer, now renamed "Steroid Hormone Recognition and Effector Complex" (SHREC) is an interdependent part of the complete GC signal propagation in which G-proteins are involved. Free SH-groups of SHREC are a prerequisite for genomic GC activity. Specific interactions between SHREC and GC-agonist/-antagonist trigger steroid-dependent signaling. However, import of the ligand into the cell terminates it. Thus, the PM-related non-genomic steroid responses are clearly linked to the GR-related genomic effects.     

Comparative incidence of cancer in HIV-AIDS patients and transplant recipients

BackgroundStudies have found a relationship between decreased immunity and increased incidence of cancer.MethodsA systematic review of observational studies evaluating the incidence of cancer in both organ recipients and people with HIV/AIDS compared with the general population. Eligible studies were searched up to March 2011 in the following databases: Pubmed, Embase, Scielo, Cancerlit and Google scholar. In this study, the standardized incidence ratios (SIR) of cancer in people with HIV/AIDS and of organ transplant recipients were compared with those found among the general population.ResultsTwenty-five studies of transplant and HIV-associated cancer risk, involving 866 776 people with HIV/AIDS or organ recipients and 21 260 new cases of cancer, were included. The risk for the development of new cancer cases was higher among people with HIV/AIDS (SIR = 4, IC95% 3.78–4.24) and who received organs (SIR = 3.28, IC95% 3.06–3.52) when compared with the general population.ConclusionSimilar SIR in both immunocompromised populations suggests that the weakened immune system is responsible for the increased risk of new cases of cancer among these groups. Research investments are needed to develop effective cancer prevention strategies in these populations.     

Evaluation of Pathological Effects in Broilers During Fumonisins and Clays Exposure

This study was conducted to evaluate the possible protector effect of bentonite and zeolite in Bovans chicks fed a diet containing 59 mg kg(-1) of fumonisin B1 (FB1) during 3 weeks. A total of 200 one-day-old male chicks were treated varying the amount of bentonite and zeolite. Chick weight was registered weekly. At the end of the experiment, all the chicks were killed, and the livers were analyzed for gross examination and histopathological changes. Plasmatic activity of alanine amino transferase and aspartate amino transferase (AST) were also determined. Sphinganine and the sphinganine-to-sphingosine ratio in serum were evaluated. Both, bentonite and zeolite showed a protector effect against FB1 adsorption in the digestive tract of chicks. Chicks fed with FB1-contaminated feed, amended either with zeolite or bentonite, were heavier, and no macroscopic lesions were observed in the livers. AST activity might be considered as an indicator for FB1 exposition because AST levels were affected when only FB1 was present in the basal diet. These results indicate that both, zeolite and bentonite can be added into feed to diminish the effects of FB1.