Profile of hMSH2 expression in breast tumors and lymph nodes: a preliminary study

OBJECTIVE

The mismatch repair (MMR) genes play a central role for the onset of cancer. One of these genes is hMSH2. A differential hMSH2 protein expression has been detected in the mononuclear fraction of peripheral blood of patients with breast cancer when compared to healthy women. This work aims to evaluate the expression of hMSH2 in patients diagnosed with breast cancer undergoing treatment at various stages of the disease to verify its potential use as a prognostic marker.

PATIENTS AND METHODS

Immunohistochemical expression of hMSH2 at different stages of breast cancer in 40 patients biopsy samples were analyzed.

RESULTS

hMSH2 has a considerable increased expression in all groups of patients with tumors, when compared to patients without tumors.

CONCLUSIONS

immunohistochemistry indeed can be a great tool for the diagnosis of breast cancer, as it is an easy and versatile technique.

The use of vancomycin with its therapeutic and adverse effects: a review

OBJECTIVE

Vancomycin (VCM) is a tricyclic glycopeptide antibiotic produced by Streptococcus orientalis. Widely used in hospitals, it is indicated to fight severe infections caused by Gram-positive bacteria, especially with the advent of MRSA (methicillin-resistant Staphylococcus aureus), penicillin-resistant pneumococci among others. Furthermore, it is indicated for the treatment of patients allergic to penicillins and cephalosporins. Dose recommendations, dilution rates and types of infusion are controversial and also result in toxic effects. Aim of this paper was to perform a literature review showing the therapeutic and adverse effects of vancomycin.

MATERIALS AND METHODS

This is a literature review of recent articles published on MEDLINE and SciELO databases in English, Portuguese and Spanish.

RESULTS

The main adverse effects of vancomycin are: hypotension, phlebitis, nephrotoxicity, ototoxicity, hypersensitivity reactions, red man syndrome, neutropenia, chills, fever, interstitial nephritis.

CONCLUSIONS

The use of vancomycin is still very common; however, inadequate doses and prolonged therapy pose a risk of increasing minimum inhibitory concentrations (MICs), resulting in subtherapeutic levels, treatment failures and toxicity. Therefore, further studies should be conducted to optimize the administration of vancomycin, monitoring treatments from the beginning in order to ensure a safe and effective use of the drug.

Survinin expression in patients with breast cancer during chemotherapy

Breast cancer (BC) is the second most common cancer worldwide and the first among women. If early diagnosed and treated, this disease has a good prognosis. However, it is believed that 90 % of all patients who have had cancer died due to metastatic disease, which highlights the need for a marker which allows the detection of latent cancer cells spread from the primary tumor. The objective of this study was to investigate the expression of survinin in peripheral blood of patients with breast cancer at diagnosis and during chemotherapy aiming correlation with minimal residual disease, clinical and pathological findings. The study included 40 patients with breast cancer and 12 healthy donors as a comparison group. Survinin expression was verified by real-time PCR. For diagnosis, survinin expression cutoff point was 1.05; considering this cutoff point, we obtained a test sensitivity of 85.3 %, specificity of 75.0 %, positive predictive value of 90.6 %, negative predictive value of 64.3 %, and accuracy of 82.6 %. There was statistical significance between groups (patients × control group), presenting to patients a significantly higher value than the control group (p < 0.001). Patients that presented at the diagnosis a survinin gene expression ≥ 1.05 are 17 times more likely to develop metastatic disease.

Safety and efficacy analysis of liposomal insulin-like growth factor-1 in a fluid gel formulation for hair-loss treatment in a hamster model

Insulin-like growth factor (IGF)-1 has shown some interesting results in studies examining its use as a hair-loss treatment. IGF-1 works by regulating cellular proliferation and migration during the development of hair follicles. Hepatotoxicity and myelotoxicity were evaluated in hamsters (Mesocricetus auratus) after topical application of the liquid gel vehicle (placebo), 1% IGF-1 or 3% IGF-1. No significant difference in the levels of aspartate aminotransferase or alanine aminotransferase was found between the control and treated groups. ELISA did not shown any increase in the plasma level of IGF-1. A haematopoietic niche was found, but it was not associated with myelotoxicity. Efficacy was determined by dermatoscopy analysis of hair density and microscopy analysis of hair diameter, with hair found to be thicker and with more rapid growth in the 3% group than in either the 1% group or the control group. These results strongly suggest that liposomal IGF-1 in a liquid gel formulation is a safe and efficient treatment for hair loss.

Integration of basic sciences in health's courses

Concepts from disciplines such as Biochemistry, Genetics, Cellular and Molecular Biology are essential to the understanding and treatment of an elevated number of illnesses, but often they are studied separately, with no integration between them. This article proposes a model for basic sciences integration based on problem-based learning (PBL) and compares failure rate, global final grade, approved student final grade, grade distribution and students' satisfaction with teacher conduction between integrated curriculum and traditional learning in health courses from Anhembi Morumbi University-a private institution from Brazil. Comparison between integrated and traditional curriculum was based on students' records obtained from first-year health sciences students. A total of 1,697 records from 2005 to 2007 (nonintegrated curriculum) and 785 records from 2008 (integrated curriculum) were selected for this study and they were necessary to get information about students' grades. Moreover, a questionnaire was applied in order to cover student's satisfaction with teacher conduction. The data presented in this study indicated that the integrated curriculum based on PBL was related to an improvement in student's grades and satisfaction compared with traditional teaching. We believe that the effectiveness in health education will be a combination of "classical" presentation of contents associated to actively involved students in the educational process and methodology based on problems in order to create the stimulus for the undergraduates continue to integrate basic and clinical investigation.

Content of liver and brain ubiquinol-9 and ubiquinol-10 after chronic ethanol intake in rats subjected to two levels of dietary alpha-tocopherol

To assess the effect of chronic ethanol ingestion in the content of the reduced forms of coenzymes Q9 (ubiquinol-9) and Q10 (ubiquinol-10) as a factor contributing to oxidative stress in liver and brain, male Wistar rats were fed ad libitum a basal diet containing either 10 or 2.5 mg alpha-tocopherol/100 g diet (controls), or the same basal diet plus a 32% ethanol-25% sucrose solution. After three months treatment, ethanol chronically-treated rats showed identical growth rates to the isocalorically pair-fed controls, irrespectively of alpha-tocopherol dietary level. Lowering dietary alpha-tocopherol led to a decreased content of this vitamin in the liver and brain of control rats, without changes in that of ubiquinol-9, and increased levels of hepatic ubiquinol-10 and total glutathione (tGSH), accompanied by a decrease in brain tGSH. At the two levels of dietary alpha-tocopherol, ethanol treatment significantly decreased the content of hepatic alpha-tocopherol and ubiquinols 9 and 10. This effect was significantly greater at 10 mg alpha-tocopherol/100 g diet than at 2.5, whereas those of tGSH were significantly elevated by 43% and 9%, respectively. Chronic ethanol intake did not alter the content of brain alpha-tocopherol and tGSH, whereas those of ubiquinol-9 were significantly lowered by 20% and 14% in rats subjected to 10 and 2.5 mg alpha-tocopherol/100 g diet, respectively. It is concluded that chronic ethanol intake at two levels of dietary alpha-tocopherol induces a depletion of hepatic alpha-tocopherol and ubiquinols 9 and 10, thus contributing to ethanol-induced oxidative stress in the liver tissue. This effect of ethanol is dependent upon the dietary level of alpha-tocopherol, involves a compensatory enhancement in hepatic tGSH availability, and is not observed in the brain tissue, probably due to its limited capacity for ethanol biotransformation and glutathione synthesis.

Absence of oxidative stress following paradoxical sleep deprivation in rats

Paradoxical sleep deprivation was performed on rats using platform technique to investigate the oxidative process associated with it. Levels of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), total glutathione (GSH) and malondialdehyde production were measured in brain of rats under control conditions (C) and those on single large platforms (SLP), multiple large platforms (MLP), single small platforms (SSP) and multiple small platforms (MSP) groups. SOD, CAT and GPx brain activity and malondialdehyde production were not modified by any of the procedures. Brain GSH, however, was significantly reduced in both SSP and SLP groups. These results suggest that paradoxical sleep deprivation per se is not associated with oxidative damage. The observed alterations could be attributed to factors such as immobilization and social isolation present in the single platform techniques.

In situ rat brain and liver spontaneous chemiluminescence after acute ethanol intake

The influence of acute ethanol administration on the oxidative stress status of rat brain and liver was assessed by in situ spontaneous organ chemiluminescence (CL). Brain and liver CL was significantly increased after acute ethanol administration to fed rats, a response that is time-dependent and evidenced at doses higher than 1 g/kg. Ethanol-induced CL development is faster in liver compared with brain probably due to the greater ethanol metabolic capacity of the liver, whereas the net enhancement in brain light emission at 3 h after ethanol treatment is higher than that of the liver, which could reflect the greater susceptibility of brain to oxidative stress. The effect of ethanol on brain and liver CL seems to be mediated by acetaldehyde, due to its abolishment by the alcohol dehydrogenase inhibitor 4-methylpyrazole and exacerbation by the aldehyde dehydrogenase inhibitor disulfiram. In brain, these findings were observed in the absence of changes in the activity of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glucose-6-phosphate dehydrogenase. However, the content of brain glutathione was significantly decreased by 31%, by ethanol, thus establishing an enhanced oxidative stress in this tissue.

Regression of morphological alterations and oxidative stress-related parameters after acute lindane-induced hepatotoxicity in rats

Changes in rat liver oxidative stress-related parameters, morphological alterations, as well as circulating and tissue levels of lindane were studied 1-7 days after the administration of a single dose of 60 mg of lindane/kg. One day after lindane treatment, a significant enhancement in the oxidative stress status of the liver was observed, characterized by an increase in thiobarbituric acid reactants production and in the microsomal generation of superoxide radical (O.-2) coupled to cytochrome P450 induction, and a decrement in the activity of superoxide dismutase (SOD) and catalase. Consequently, the O.-2 production/SOD activity ratio was enhanced two-fold. In this condition, light microscopy studies revealed the incidence of liver lesions in periportal areas, together with significant changes at the mitochondrial level observed by electron microscopy, which coincide with the maximal levels of lindane in the liver, adipose tissue, plasma and whole blood. Changes in oxidative stress-related parameters observed after 1 day of lindane treatment regressed to normal from the third day and thereafter, together with the decrement in circulating and tissue levels of the insecticide. It is concluded that morphological and oxidative stress-related changes induced in the liver by acute lindane intoxication are readily reversible, depend on the hepatic content of the insecticide, and seem to be conditioned by the changes in O.-2 generation.

Chronic fenfluramine treatment of rats with different ages: effects on brain oxidative stress-related parameters

Fenfluramine is an anorectic drug widely used for the regulation of food intake that presents some adverse effects at the central and peripheral levels. d-Fenfluramine, an isomer of dl-fenfluramine, is postulated to be more effective and to induce less side effects than the racemic compound. These drugs act preferentially on the serotonergic system. Some authors have suggested that fenfluramine causes a degeneration of serotonergic neurons. Alterations of the serotonergic system are also observed during the aging process, and in this case, a relationship with reactive oxygen species has been already established. In view of these data, the present study was conducted to investigate the relationship between fenfluramine and brain antioxidant defense system in mature and aged animals. Rats aged 4 and 17 months were chronically treated with dl-fenfluramine, d-fenfluramine, or saline. Brain activity of superoxide dismutase and glutathione peroxidase was significantly affected by aging. Catalase activity was altered by the treatment. Total glutathione content and chemiluminescence in the brains were also altered by aging. Glutathione levels were altered as a function of the interaction between age and treatment. These findings suggest that treatment with d- or dl-fenfluramine results in alteration of the anti-oxidant system that could be exacerbated when associated with the aging process.

Antioxidant defense in rat brain after chronic treatment with anorectic drugs

Mazindol (5-hydroxy-5-p-chlorophenyl-2,3-dihydro-5H-imidazo-2,1-a-isoindole) although not chemically related to the phenylethylamine group, shows a pharmacological profile similar to that of amphetamines. In rats these anorectic drugs enhance dopamine (DA) turnover, which is the mechanism that causes anorexia. It has been hypothesized that amphetamine causes a long-lasting depletion of DA, a decrease of dopaminergic transport pumps and nerve terminal degeneration increasing. These actions provide a cellular environment encouraging the autoxidation of DA that may lead to lipid peroxidation and neuronal damage. Considering that both drugs may cause neuronal damage by oxidative mechanisms, this study was conducted to investigate the action of mazindol and methamphetamine on brain cell antioxidant defense system and to investigate whether animal age is important in the antioxidant response to chronic anorectic administration. The activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), as well as the total glutathione (GSH) content in brains of rats, were measured. The animals (2 groups with 5 and 18 months old) were treated for 5 months (i.p.) with mazindol (10 mg/kg body weight/day), methamphetamine (2.5 mg/kg body weight/day) or saline. The results obtained showed no differences between SOD, CAT, GPx activities and GSH content in the brain of animals treated with saline compared with both drugs, either in 10-month or 23-month groups. On the other hand, brain total GSH content of old animals was found to be lower than that from young ones, independent of the treatment. SOD activity was found to be increased, CAT unchanged and GPx decreased, in the brain of old animals, treated with both drugs or saline. These findings led us to conclude that the chronic administration of mazindol and methamphetamine have no effects on the antioxidant systems studied either in young (10 months) or in old (23 months) rats.

Prooxidant and antioxidant hepatic factors in rats chronically fed an ethanol regimen and treated with an acute dose of lindane

While acute lindane treatment and chronic ethanol feeding to rats have been associated with hepatic oxidative stress, the possible roles of these stresses in the pathogenesis of hepatic lesions reported in acute lindane intoxication and in those observed in some models of chronic alcoholism have not been established. Our previous studies in rats chronically fed ethanol regimens and then treated with a single intraperitoneal (i.p.) dose of lindane (20 mg/kg) showed that while lindane per se was invariably associated with hepatic oxidative stress, chronic ethanol feeding only produced this stress when the dietary level of vitamin E was relatively low. Chronic ethanol pretreatment did not significantly affect the lindane-associated oxidative stress, and neither chronic ethanol feeding nor acute lindane, single or in combination, produced any histologic and biochemical evidence of liver damage. In the present experiment, the acute dose of lindane was increased to 40 mg/kg, and we have studied a larger number of prooxidant and antioxidant hepatic factors. Male Wistar rats (115.5 +/- 5.4 g) were fed ad lib for 11 weeks a calorically well-balanced and nutritionally adequate basal diet, or the same basal diet plus a 32% ethanol/25% sucrose solution, also ad lib, and were then injected i.p. with a single dose of lindane or with equivalent amounts of corn oil. The results indicated that acute lindane treatment to naive rats increased practically all the prooxidant hepatic factors examined (cytochromes P450 and b5, NADPH cytochrome c reductase, NADPH oxidase), as well as the generation of microsomal superoxide radical and thiobarbituric acid reactive substances of liver homogenates, but did not modify any of the antioxidant hepatic factors studied. Conversely, the chronic administration of ethanol alone did not significantly affect the prooxidant hepatic factors but reduced some of the antioxidants (i.e., the activities of GSH-Px and the contents of alpha-tocopherol and ubiquinols 9 and 10). Although chronic ethanol pretreatment further increased the superoxide generation induced by lindane per se, it did not increase but generally reduced the effects of lindane per se on the other prooxidant factors studied. Furthermore, although acute lindane administration to ethanol-pretreated rats was associated with decreases in GSH and catalase (not affected by ethanol or lindane treatment alone), it did not substantially modify the reducing effects of ethanol feeding per se on GSH-Px, alpha-tocopherol, and ubiquinols. Once again, neither chronic ethanol feeding nor lindane treatment, single or in combination, was associated with any evidence of liver damage.

Acute lindane intoxication: a study on lindane tissue concentration and oxidative stress-related parameters in liver and erythrocytes

Treatment of rats with daily doses of 20 mg of lindane/kg for 3 consecutive days led to the accumulation of the insecticide in several tissues, including erythrocytes and liver. Lindane did not alter the hematocrit and hemoglobin concentration but reduced methemoglobin levels by 17%. Red blood cells from controls and lindane-treated rats, exposed to t-butyl hydroperoxide, exhibited comparable rates of oxygen uptake and visible chemiluminescence, whereas the induction period that precedes oxygen uptake was significantly enhanced in the latter group. Lindane treatment did not modify the activity of erythrocyte glutathione peroxidase, glucose-6-phosphate dehydrogenase, catalase, and methemoglobin reductase, being the total content of glutathione and superoxide dismutase activity significantly increased. The liver from lindane-treated rats showed an enhanced microsomal pro-oxidant activity, evidenced by higher cytochrome P450 content and NADPH-cytochrome c reductase and NADPH oxidase activities. The higher enzyme activities led to an increased superoxide anion generation (adrenochrome formation) and lipid peroxidation (measured either by the production of thiobarbituric acid reactants and spontaneous visible chemiluminescence). Concomitantly, liver glutathione content and the activity of glutathione peroxidase-glutathione reductase couple were augmented by lindane treatment, without any change in superoxide dismutase activity, together with a reduction in that of catalase. Results suggest that lindane does not alter the prooxidant/antioxidant status of the erythrocyte in conditions of a significant cellular accumulation of the insecticide, which might exert direct action on enzymatic systems leading to enhanced superoxide dismutase activity and glutathione content.(ABSTRACT TRUNCATED AT 250 WORDS)

Dose-dependent study of liver lipid peroxidation related parameters in rats treated with pp'-DDT

Rats treated with increasing doses of pp'-DDT (60, 100 and 180 mg/kg body wt.) i.p., for 24 h, showed a dose-independent increase in liver cytochrome P450 levels, together with an increase in lipid peroxidation, measured as production of thiobarbituric acid reactants. This oxidant condition elicited in the liver by DDT was not accompanied by any change in the activity of NADPH-cytochrome c reductase or in the rate of superoxide anion generation by liver microsomal fraction. The activities of superoxide dismutase and glutathione peroxidase were found to be increased in the higher dose DDT-treated rats, without any change in those from catalase and glutathione reductase. The results presented showed an oxidant condition in the liver elicited by DDT treatment of rats, without any adequate hypothesis proposed to explain these data.

Differential effects of short-term lindane administration on parameters related to oxidative stress in rat liver and erythrocytes

Parameters related to oxidative stress in rat liver and erythrocytes were studied after short-term administration (60 and 90 days) of 1000 ppm of lindane in the diet. Lindane induced an oxidative stress condition in the liver, which is related to an enhancement in microsomal NADPH-cytochrome c reductase and NADPH oxidase activities, superoxide radical formation and cytochrome P450 content, produced independently of the time of treatment. Also, decreased activities of glutathione peroxidase and catalase were concomitantly observed. Although these changes were paralleled by an increase in lipid peroxidation indices, such as production of thiobarbituric acid reactants and spontaneous chemiluminescence, no evidence of liver injury was obtained. Lindane treatment did not exert quantitatively important changes in the pro-oxidant/anti-oxidant status of the erythrocyte, with reduction in the red blood cell mass possibly reflecting actions of the insecticide on the erythropoietic process.

Turnover of hepatic glutathione after acute lindane intoxication

The administration of lindane (60 mg/kg) to fed rats diminished the content of hepatic glutathione (GSH) 4 h after treatment, which was recovered at 24 h. At these experimental times, the activities of glutathione peroxidase, glutathione reductase, glutathione-S-transferases and gamma-glutamyltransferase in the liver of lindane-treated rats and control animals were comparable. Liver GSH turnover, measured after a pulse of [35S]cysteine, was enhanced by 69% (P < 0.05) in lindane-treated rats 24 h after intoxication compared to controls, with a 63% (P < 0.05) increase in the estimated rate of GSH synthesis. It is concluded that lindane enhances GSH synthesis in rat liver 24 h after treatment as a consequence of the decrement in its content observed at early times of intoxication (4 h), thus allowing the recovery of the normal level of hepatic GSH.

Effect of phenobarbital and 3-methylcholanthrene on the early oxidative stress component induced by lindane in rat liver

1. Lindane administered to untreated rats or rats pretreated with phenobarbital (PB) or 3-methylcholanthrene (MC) increased liver lipid peroxidation, of the same magnitude in all groups. 2. PB pretreatment produced a 50% increase in lipid peroxidation (TBAR) by liver homogenates and microsomes, an effect accompanied by increases in cytochrome P-450, NADPH-cytochrome P-450 reductase, NADPH oxidase and microsomal superoxide anion production, MC pretreatment resulted in increases in liver cytochrome P-450 and NADPH oxidase only. 3. Pretreatment of rats with PB, but not MC or lindane, gave increases in glutathione peroxidase and reductase. 4. Pretreatment with PB, but not MC, increased liver GSH. Lindane decreased liver GSH to the same extent as PB plus lindane. 5. Biliary GSH, GSSG and bile flow were decreased by lindane to similar extents in all groups. 6. Lindane induced periportal necrosis with haemorrhagic foci in all groups. 7. Data presented indicate that the early lipid peroxidative response of liver to lindane was unchanged by PB- or MC-stimulated hepatic microsomal enzyme induction.

Effects of hyperthyroidism on rat liver glutathione metabolism: related enzymes' activities, efflux, and turnover

The effect of hyperthyroidism on liver glutathione (GSH) metabolism was studied in fed rats after the administration of 0.1 mg T3/kg body wt, for 1-3 consecutive days. T3-calorigenesis resulted in elevated rates of O2 consumption by the liver, together with higher lipid peroxidative processes and GSH depletion, compared to the euthyroid state. The study of the enzymes related to GSH metabolism revealed no significant changes in the activity of glutathione peroxidase and glutathione reductase, with decreases (27-41%) in the activity of glutathione-S-transferases and marked elevation (133%) in that of gamma-glutamyl transferase, 3 days after T3 treatment. At this experimental time, the activity of the NADPH generating enzyme glucose-6-phosphate dehydrogenase was enhanced by 84% in the liver of T3-treated rats, compared to that in the controls. In these conditions, the canalicular efflux of GSH was not altered by T3, whereas net and fractional rates of sinusoidal GSH efflux were enhanced by 86% and 288%, respectively. The latter effect of hyperthyroidism was found in parallel with an enhancement in sinusoidal lactate dehydrogenase and protein release, suggesting that loss of GSH might be related to a permeabilization of the hepatocyte plasma membrane. Liver GSH turnover assessed after a pulse of [35S]cysteine resulted in a 209% increase in the fractional turnover rate in hyperthyroid rats over controls, under steady state conditions for both hepatic GSH pools, leading to a 62% enhancement in the respective turnover flux. Data suggest that the elevation in the sinusoidal GSH efflux from the liver and in the hepatic capacity to degrade the tripeptide are major mechanisms leading to GSH depletion in the liver of T3-treated rats. As the increased GSH use is not balanced by the elevation in GSH synthesis, a lower steady state level of GSH is attained in the liver.