Time course of hydrogen peroxide-thioredoxin balance and its influence on the intracellular signalling in myocardial infarction

We investigated the myocardial thioredoxin-1 and hydrogen peroxide concentrations and their association with some prosurvival and pro-apoptotic proteins, during the transition from myocardial infarction (MI) to heart failure in rats. Male Wistar rats were divided into the following six groups: three sham-operated groups and three MI groups, each at at 2, 7 and 28 days postsurgery. Cardiac function was analysed by echocardiography; the concentration of H(2)O(2) and the ratio of reduced to oxidized glutathione were measured spectrophotometrically, while the myocardial immunocontent of thioredoxin-1, angiotensin II, angiotensin II type 1 and type 2 receptors, p-JNK/JNK, p-ERK/ERK, p-Akt/Akt, p-mTOR/mTOR and p-GSK3β/GSK3β was evaluated by Western blot. Our results show that thioredoxin-1 appears to make an important contribution to the reduced H(2)O(2) concentration. It was associated with lower JNK expression in the early period post-MI (2 days). However, thioredoxin-1 decreased, while renin-angiotensin system markers and levels of H(2)O(2) increased, over 28 days post-MI, in parallel with some signalling proteins involved in maladaptative cardiac remodelling and ventricular dysfunction. These findings provide insight into the time course profile of endogenous antioxidant adaptation to ischaemic injury, which may be useful for the design of therapeutical strategies targeting oxidative stress post-MI.     

Annexin A1 modulates natural and glucocorticoid-induced resolution of inflammation by enhancing neutrophil apoptosis

This study aimed at assessing whether AnxA1, a downstream mediator for the anti-inflammatory effects of GCs, could affect the fate of immune cells in tissue exudates, using LPS-induced pleurisy in BALB/c mice. AnxA1 protein expression in exudates was increased during natural resolution, as seen at 48-72 h post-LPS, an effect augmented by treatment with GC and associated with marked presence of apoptotic neutrophils in the pleural exudates. The functional relevance of AnxA1 was determined using a neutralizing antibody or a nonspecific antagonist at FPR/ALXRs: either treatment inhibited both spontaneous and GC-induced resolution of inflammation. Injection of Ac2-26 (100 μg, given 4 h into the LPS response), an AnxA1-active N-terminal peptide, promoted active resolution and augmented the extent of neutrophil apoptosis. Such an effect was prevented by the pan-caspase inhibitor zVAD-fmk. Mechanistically, resolution of neutrophilic inflammation was linked to cell apoptosis with activation of Bax and caspase-3 and inhibition of survival pathways Mcl-1, ERK1/2, and NF-κB. These novel in vivo data, using a dynamic model of acute inflammation, provide evidence that AnxA1 is a mediator of natural and GC-induced resolution of inflammation with profound effects on neutrophil apoptosis.     

Ursolic acid and oleanolic acid suppress preneoplastic lesions induced by 1,2-dimethylhydrazine in rat colon

Ursolic acid (UA) and oleanolic acid (OA) are pentacyclic triterpenoid compounds found in plants used in the human diet and in medicinal herbs, in the form of aglycones or as the free acid. These compounds are known for their hepatoprotective, anti-inflammatory, antimicrobial, hypoglycemic, antimutagenic, antioxidant, and antifertility activities. In the present study, we evaluated the effects of UA and OA on the formation of 1,2-dimethyl-hydrazine (DMH)-induced aberrant crypt foci (ACF) in the colon of the male Wistar rat. The animals received subcutaneous (sc) injections of DMH (40 mg/kg body weight) twice a week for two weeks to induce ACF. UA, OA and a mixture of UA and OA were administered to the rats five times a week for four weeks by gavage at doses of 25 mg/kg body weight/day each, during and after DMH treatment. All animals were sacrificed in week 5 for the evaluation of ACF. The results showed a significant reduction in the frequency of ACF in the group treated with the triterpenoid compounds plus DMH when compared to those treated with DMH alone, suggesting that UA and OA suppress the formation of ACF and have a protective effect against colon carcinogenesis.     

MSI-L gastric carcinomas share the hMLH1 methylation status of MSI-H carcinomas but not their clinicopathological profile

Sporadic gastric carcinomas (SGC) with microsatellite instability (MSI) exhibit mutations in target genes and display a particular clinicopathological profile. In SGC the MSI phenotype has been associated with hMLH1 promoter hypermethylation. Fifty-seven SGC, classified as high-frequency MSI (MSI-H), low-frequency MSI (MSI-L), and microsatellite stable (MSS), were analyzed for hMLH1 promoter methylation status and clinicopathological features. hMLH1 mutations and hMLH1 expression, as well as target gene mutations, were also evaluated. Our aims were to characterize the molecular and clinicopathological features of SGC, with and without hMLH1 promoter hypermethylation, and to compare the molecular and clinicopathological features of MSI-L, MSI-H, and MSS tumors in an attempt to clarify the place of MSI-L tumors in the mismatch repair (MMR) pathway. Hypermethylation of hMLH1 promoter occurred in 27 of 57 SGC (47.3%) and was significantly associated with MSI status, target gene mutations, and expansive pattern of growth of the tumors. Seventy-five percent of the MSI-H and 50% of MSI-L carcinomas showed hypermethylation (Met+) of hMLH1 in contrast to 0% in MSS carcinomas. No hMLH1 expression was observed in MSI-L/Met+ and MSI-H/Met+ cases. MSS and MSI-L tumors share the same clinicopathological profile regardless of the methylation status of the latter and are distinct from MSI-H tumors. We conclude that mutations in target genes, more than hypermethylation or absence of expression of hMLH1, are the link between MSI status and most of the clinicopathological features of SGC.     

Effect of preeclampsia on human milk cytokine levels

Introduction: Preeclampsia (PE) is a systemic inflammatory disease, and its effect on human milk immune components is poorly understood.

Objective: To investigate whether PE affects human milk cytokine levels.

Methods: This was a prospective observational study involving mothers diagnosed with PE and with singleton pregnancy with no fetal malformation. The following cases were excluded: diabetes, chorioamnionitis, use of illicit drugs and alcohol, mastitis and congenital infection. In total, 228 mothers were studied and divided into two groups matched by gestational age: PE (n?=?114) and normotensive (control, n?=?114). Colostrum was collected from 24–72?hours postpartum, and mature milk was collected at the end of the first month. Cytokines (IL-1β, IL-6, IL-8, IL-10, IL-12, and TNF-α) were measured using flow cytometry. A generalized linear model with a gamma distribution was used to analyze the differences between groups versus time interaction.

Results: The mean gestational age was 36 weeks. Increased IL-1 and IL-6 levels and reduced IL-12 levels in the colostrum were detected in PE, while in the mature milk, the IL-6 and IL-8 levels were lower than those of the control group.

Conclusions: PE is associated with increased levels of inflammatory cytokines in colostrum and decreased levels in mature milk.     

Leishmania major-Like Antigen for Specific and Sensitive Serodiagnosis of Human and Canine Visceral Leishmaniasis

An antigen (LMS) prepared from Leishmania major-like promastigotes was used in an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of human and dog visceral leishmaniasis. The results were compared with those from the indirect immunofluorescent antibody test (IFAT). A total of 1,822 canine sera were tested, including sera from dogs with visceral leishmaniasis, transmissible venereal tumors, ehrlichiosis, rickettsiosis, or Chagas' disease and sera from healthy dogs. The antigen was also tested with 227 samples of human sera, including sera from patients with visceral, cutaneous, or diffuse cutaneous leishmaniasis and from noninfected individuals, as well as sera from patients with Chagas' disease, toxoplasmosis, rickettsiosis, hepatitis B, schistosomiasis, ascaridiasis, malaria, rheumatoid factor, leprosy and rheumatoid factor, tuberculosis, or leprosy. All dogs and all human patients had a clinical and/or serological and/or parasitological diagnosis. For detecting antibodies in sera from dogs with leishmaniasis, the antigen showed a sensitivity of 98%, specificity of 95%, and concordance of 93% and when used for detecting antibodies in human sera presented a sensitivity of 92%, specificity of 100%, and concordance of 92%. Comparison between ELISA and IFAT demonstrated that ELISA using the LMS antigen yielded more reliable results than IFAT. The LMS antigen displayed no cross-reactivity with sera from patients or dogs that had any of the other diseases tested.     

Transplantation of Hematopoietic Stem Cells for Primary Immunodeficiencies in Brazil: Challenges in Treating Rare Diseases in Developing Countries

The results of hematopoietic stem cell transplant (HSCT) for primary immunodeficiency diseases (PID) have been improving over time. Unfortunately, developing countries do not experience the same results. This first report of Brazilian experience of HSCT for PID describes the development and results in the field. We included data from transplants in 221 patients, performed at 11 centers which participated in the Brazilian collaborative group, from July 1990 to December 2015. The majority of transplants were concentrated in one center (n?=?123). The median age at HSCT was 22 months, and the most common diseases were severe combined immunodeficiency (SCID) (n?=?67) and Wiskott-Aldrich syndrome (WAS) (n?=?67). Only 15 patients received unconditioned transplants. Cumulative incidence of GVHD grades II to IV was 23%, and GVHD grades III to IV was 10%. The 5-year overall survival was 71.6%. WAS patients had better survival compared to other diseases. Most deaths (n?=?53) occurred in the first year after transplantation mainly due to infection (55%) and GVHD (13%). Although transplant for PID patients in Brazil has evolved since its beginning, we still face some challenges like delayed diagnosis and referral, severe infections before transplant, a limited number of transplant centers with expertise, and resources for more advanced techniques. Measures like newborn screening for SCID may hasten the diagnosis and ameliorate patients’ conditions at the moment of transplant.     

Creatine supplementation prevents acute strength loss induced by concurrent exercise

Purpose

To investigate the effect of creatine (CR) supplementation on the acute interference induced by aerobic exercise on subsequent maximum dynamic strength (1RM) and strength endurance (SE, total number of repetitions) performance.

Methods

Thirty-two recreationally strength-trained men were submitted to a graded exercise test to determine maximal oxygen consumption (VO_2max: 41.56 ± 5.24 ml kg^?1 min^?1), anaerobic threshold velocity (AT_v: 8.3 ± 1.18 km h^?1), and baseline performance (control) on the 1RM and SE (4 × 80 % 1RM to failure) tests. After the control tests, participants were randomly assigned to either a CR (20 g day^?1 for 7 days followed by 5 g day^?1 throughout the study) or a placebo (PL-dextrose) group, and then completed 4 experimental sessions, consisting of a 5-km run on a treadmill either continuously (90 % AT_v) or intermittently (1:1 min at vVO_2max) followed by either a leg- or bench-press SE/1RM test.

Results

CR was able to maintain the leg-press SE performance after the intermittent aerobic exercise when compared with C (p > 0.05). On the other hand, the PL group showed a significant decrease in leg-press SE (p ≤ 0.05). CR supplementation significantly increased bench-press SE after both aerobic exercise modes, while the bench-press SE was not affected by either mode of aerobic exercise in the PL group. Although small increases in 1RM were observed after either continuous (bench press and leg press) or intermittent (bench press) aerobic exercise in the CR group, they were within the range of variability of the measurement. The PL group only maintained their 1RM.

Conclusions

In conclusion, the acute interference effect on strength performance observed in concurrent exercise may be counteracted by CR supplementation.