Oncogenic and tumor suppressor pathways in subchronic aflatoxicosis in rats: Association with serum and urinary aflatoxin exposure biomarkers.

In this study, the changes in oncogenic and tumor suppressor signaling pathways in liver and their association with serum and urinary biomarkers of aflatoxin exposure were evaluated in Wistar rats fed diets containing aflatoxin B1 (AFB1) for 90 days. Rats were divided into four groups (n = 15 per group) and assigned to dietary treatments containing 0 (control), 50 (AFB50), 100 (AFB100) and 200 µg AFB1 kg-1 diet (AFB200). Multiple preneoplastic foci of hepatocytes marked with glutathione-S-transferase-placental form (GST-P) were identified in AFB100 and AFB200 groups. Hepatocellular damage induced by AFB1 resulted in overexpression of cyclin D1 and ß-catenin. The liver expression of retinoblastoma (Rb) and p27Kip1 decreased in AFB100 and AFB200 groups, confirming the favorable conditions for neoplastic progression to hepatocellular carcinoma. All samples from rats fed AFB1-contaminated diets had quantifiable AFB1-lysine in serum or urinary AFM1 and AFB1-N7-guanine, with mean levels of 20.42-50.34 ng mL-1, 5.31-37.68 and 39.15-126.37 ng mg-1 creatinine, respectively. Positive correlations were found between AFB1-lysine, AFM1 or AFB1-N7-guanine and GST-P+, ß-catenin+ and cyclin D1+ hepatocytes, while Rb + cells negatively correlated with those AFB1 exposure biomarkers. The pathways evaluated are critical molecular mechanisms of AFB1-induced hepatocarcinogenesis in rats.

PKM2 promotes Th17 cell differentiation and autoimmune inflammation by fine-tuning STAT3 activation.

Th17 cell differentiation and pathogenicity depend on metabolic reprogramming inducing shifts toward glycolysis. Here, we show that the pyruvate kinase M2 (PKM2), a glycolytic enzyme required for cancer cell proliferation and tumor progression, is a key factor mediating Th17 cell differentiation and autoimmune inflammation. We found that PKM2 is highly expressed throughout the differentiation of Th17 cells in vitro and during experimental autoimmune encephalomyelitis (EAE) development. Strikingly, PKM2 is not required for the metabolic reprogramming and proliferative capacity of Th17 cells. However, T cell-specific PKM2 deletion impairs Th17 cell differentiation and ameliorates symptoms of EAE by decreasing Th17 cell-mediated inflammation and demyelination. Mechanistically, PKM2 translocates into the nucleus and interacts with STAT3, enhancing its activation and thereby increasing Th17 cell differentiation. Thus, PKM2 acts as a critical nonmetabolic regulator that fine-tunes Th17 cell differentiation and function in autoimmune-mediated inflammation.

Thirty days after anterior cruciate ligament transection is sufficient to induce signs of knee osteoarthritis in rats: pain, functional impairment, and synovial inflammation.

OBJECTIVE: To compare the unilateral signs of knee osteoarthritis (KOA) 30 and 60 days after anterior cruciate ligament transection (ACLT). Pain, gait function, synovial fluid inflammation, and histopathological changes in the synovial membrane were analyzed, as well as the interaction between the variables. MATERIALS AND METHODS: Male Wistar rats (n = 32; 219.2 ± 18.6 g) were randomly distributed into four groups of eight animals each. Two groups were submitted to unilateral ACLT surgery to induce KOA and analyzed after 30 (KOA30) and 60 days (KOA60). Two control groups (without surgery) were also assessed after the same time periods (C30 and C60). All the groups were evaluated before ACLT from the least to most stressful tests (skin temperature, mechanical response threshold, gait test, thermal response threshold, and joint swelling), as well as 30 and 60 days after surgery. After euthanasia, the synovial fluid and synovial membrane were collected. RESULTS: Thirty days after ACLT, KOA30 showed decrease paw print area and mechanical response threshold, higher joint swelling, skin temperature, leukocyte count, cytokine levels, and synovitis score. No differences were found between KOA30 and KOA60. CONCLUSION: Our data showed that 30 days after ACLT is sufficient to induce signs of KOA in rats, such as pain, functional impairment, and synovial inflammation, suggesting that a shorter time period can be used as an experimental model.

Galectin-3 aggravates experimental polymicrobial sepsis by impairing neutrophil recruitment to the infectious focus.

Sepsis is an overwhelming systemic inflammation resulting from an uncontrolled infection that causes extensive tissue damage, organ dysfunction and eventually death. A growing body of evidence indicates that impaired neutrophil migration to the site of infection is associated with poor outcome in sepsis. Here we show that galectin-3 (Gal-3), an endogenous glycan-binding protein, plays a critical role in sepsis outcome. We found that serum Gal-3 concentration increased in patients with septic shock and mice undergoing sepsis induced by cecal ligation and puncture (CLP). Mice deficient in Gal-3 (Gal-3 KO) are more resistant to sepsis induced by CLP, showing lower levels of biochemical markers and neutrophil infiltration for organ injury/dysfunction than those observed in wild-type mice (WT). Furthermore, Gal-3 KO mice show an increased number of neutrophils in the primary focus of infection and reduced bacterial loads in the peritoneal cavity, blood, and lungs. Mechanistically, blood neutrophils from septic mice show higher levels of surface-bound Gal-3 than neutrophils from naive mice. The deficiency of Gal-3 was associated with increased rolling and adhesion of these cells in mesenteric venules. Our results indicate that Gal-3, secreted during sepsis, inhibits neutrophil migration into the infectious focus, which promotes the bacterial spread and worsens the outcome of sepsis.

Aflatoxin B1 residues in human livers and their relationship with markers of hepatic carcinogenesis in São Paulo, Brazil.

In this study, hepatic biopsies from autopsy cases in São Paulo, Brazil, showing hepatocellular carcinoma (HCC, n = 8), cirrhosis associated with viral hepatitis (VC, n = 20), cirrhosis associated with alcoholism (AC, n = 20), and normal livers (NL or controls, n = 10) were subjected to determination of aflatoxin B1 (AFB1) and its main metabolites, and of markers of hepatic carcinogenesis Only non-metabolized AFB1 was detected in 13 samples (27.1%, N = 48) of liver disorders (HCC, VC and AC), at levels between 10.0 and 418.0 pg/g (mean: 76.6 ± 107.7 pg/g). Immuno-labeling of p53, cyclin D1, p21, ß-catenin, and Prohibitin (PB) increased mainly in HCC patients, in relation to the controls. AFB1+ samples of HCC presented higher expressions of p53, cyclin D1, p21, and ß-catenin compared with AFB1-livers. In contrast, p27, p16, and Rb immuno-labeling decreased in HCC, VC, and AC samples, compared with NL, with lowest values in AFB1+ samples for all liver disorders. Compared with NL, gene expression of cyclin D1 and PB in AFB1+ samples of HCC and AC were also higher, along with higher gene expression of p21 in VC and AC AFB1+ livers. Results indicated that patients with liver disorders were exposed to dietary aflatoxins, and that residual AFB1 in liver negatively affected the p53 and protein Rb pathways in HCC. Moreover, the presence of AFB1 in cirrhotic livers warrants concern about the potential contribution of dietary aflatoxin to disease progression during VC and AC.

The Atypical Chemokine Receptor ACKR2 is Protective Against Sepsis.

Sepsis is a systemic inflammatory response as a result of uncontrolled infections. Neutrophils are the first cells to reach the primary sites of infection, and chemokines play a key role in recruiting neutrophils. However, in sepsis chemokines could also contribute to neutrophil infiltration to vital organs leading to multiple organ failure. ACKR2 is an atypical chemokine receptor, which can remove and degrade inflammatory CC chemokines. The role of ACK2 in sepsis is unknown. Using a model of cecal ligation and puncture (CLP), we demonstrate here that ACKR2 deficient () mice exhibited a significant reduction in the survival rate compared with similarly treated wild-type (WT) mice. However, neutrophil migration to the peritoneal cavity and bacterial load were similar between WT and ACKR2 mice during CLP. In contrast, ACKR2 mice showed increased neutrophil infiltration and elevated CC chemokine levels in the lung, kidney, and heart compared with the WT mice. In addition, ACKR2 mice also showed more severe lesions in the lung and kidney than those in the WT mice. Consistent with these results, WT mice under nonsevere sepsis (90% survival) had higher expression of ACKR2 in these organs than mice under severe sepsis (no survival). Finally, the lungs from septic patients showed increased number of ACKR2 cells compared with those of nonseptic patients. Our data indicate that ACKR2 may have a protective role during sepsis, and the absence of ACKR2 leads to exacerbated chemokine accumulation, neutrophil infiltration, and damage to vital organs.

Congenital Zika Virus Infection Induces Severe Spinal Cord Injury.

We report 2 fatal cases of congenital Zika virus (ZIKV) infection. Brain anomalies, including atrophy of the cerebral cortex and brainstem, and cerebellar aplasia were observed. The spinal cord showed architectural distortion, severe neuronal loss, and microcalcifications. The ZIKV proteins and flavivirus-like particles were detected in cytoplasm of spinal neurons, and spinal cord samples were positive for ZIKV RNA.

Lapachol, a compound targeting pyrimidine metabolism, ameliorates experimental autoimmune arthritis.

BACKGROUND: The inhibition of pyrimidine biosynthesis by blocking the dihydroorotate dehydrogenase (DHODH) activity, the prime target of leflunomide (LEF), has been proven to be an effective strategy for rheumatoid arthritis (RA) treatment. However, a considerable proportion of RA patients are refractory to LEF. Here, we investigated lapachol (LAP), a natural naphthoquinone, as a potential DHODH inhibitor and addressed its immunosuppressive properties. METHODS: Molecular flexible docking studies and bioactivity assays were performed to determine the ability of LAP to interact and inhibit DHODH. In vitro studies were conducted to assess the antiproliferative effect of LAP using isolated lymphocytes. Finally, collagen-induced arthritis (CIA) and antigen-induced arthritis (AIA) models were employed to address the anti-arthritic effects of LAP. RESULTS: We found that LAP is a potent DHODH inhibitor which had a remarkable ability to inhibit both human and murine lymphocyte proliferation in vitro. Importantly, uridine supplementation abrogated the antiproliferative effect of LAP, supporting that the pyrimidine metabolic pathway is the target of LAP. In vivo, LAP treatment markedly reduced CIA and AIA progression as evidenced by the reduction in clinical score, articular tissue damage, and inflammation. CONCLUSIONS: Our findings propose a binding model of interaction and support the ability of LAP to inhibit DHODH, decreasing lymphocyte proliferation and attenuating the severity of experimental autoimmune arthritis. Therefore, LAP could be considered as a potential immunosuppressive lead candidate with potential therapeutic implications for RA.

Discrepancies Between Clinical Diagnoses and Autopsy Findings in Critically Ill Children: A Prospective Study.

OBJECTIVES: To evaluate the discrepancies between clinical and autopsy diagnoses in patients who died in the pediatric intensive care units (PICUs) of a tertiary care university hospital. METHODS: A prospective study of all consecutive autopsies discussed at monthly mortality conferences over 5 years. Discrepancies between premortem and autopsy diagnoses were classified according to modified Goldman et al criteria. RESULTS: From January 1, 2011, to December 31, 2015, a total of 2,679 children were admitted to the two PICUs of our hospital; 257 (9.6%) died, 150 (58.4%) underwent autopsy, and 123 were included. Complete concordance between clinical and postmortem diagnoses was observed in 86 (69.9%) patients; 20 (16.3%) had a class I discrepancy, and eight (6.5%) had a class II discrepancy. Comparing 2011 and 2015, the rate of major discrepancies decreased from 31.6% to 15%. CONCLUSIONS: Our results emphasize the importance of autopsy to clarify the cause of death and its potential contribution to improvement of team performance and quality of care.

Inhibition of Hepatocarcinogenesis by ArtinM via Anti-proliferative and Pro-apoptotic Mechanisms.

ArtinM is a d-mannose-binding lectin found in the seeds of Artocarpus heterophyllus (jackfruit) that interacts with N-glycans, that is associated with receptors on the surface of phagocytic cells and induces the production of inflammatory mediators. Some of them are especially important because they may be required for antitumor immune response. This study aimed to evaluate the effect of ArtinM on hepatocellular preneoplastic foci. Wistar rats received 50 mg/kg of diethyl-nitrosamine (DEN) intraperitoneal weekly for 12 weeks. From the 14th week, the treated animals received 50 µg/kg of ArtinM subcutaneous every 2 weeks until the 18th week, whereas control animals were injected with vehicle alone. Preneoplastic-related factors were estimated using histological, western blotting and RT-PCR analysis. In comparison to the groups exposed to DEN, the ArtinM-treated rats showed diminution of preneoplastic foci, decreased expression of proliferating cell nuclear antigen (PCNA), increased number of nuclear p21 and p27 stained cells, augmented number of apoptotic cells, increased expression of p53, p42/44 MAPK and p21 proteins, reduced cyclin D1 (CCND1) protein levels and increased expression of TNFα and IFNγ genes. No difference was observed in interleukin 12 (IL12) protein levels. These findings indicate that ArtinM may provide protection against hepatocarcinogenesis as a result of the induction of cell-cycle blockage and pro-apoptotic mechanisms.

Unraveling the expression of the oncogene YAP1, a Wnt/beta-catenin target, in adrenocortical tumors and its association with poor outcome in pediatric patients.

BACKGROUND: Overexpression of the oncogene yes-associated-protein-1 (YAP1) is associated with increased cell proliferation in human cancers. YAP1 is a potential target of the Wnt/beta-catenin pathway, which plays an important role in adrenocortical tumors (ACT). The role of YAP1 in adrenocortical tumorigenesis has not been assessed. AIMS: To evaluate YAP1 expression in normal adrenals and pediatric ACT and its association with disease outcome. To investigate the interaction between YAP1 and the Wnt/beta-catenin pathway in adrenocortical cells. RESULTS: Strong YAP1 staining was present in fetal adrenals and pediatric ACT but weak in postnatal adrenals. In pediatric ACT, YAP1 mRNA overexpression was associated with death, recurrent/metastatic disease and lower overall survival. The inhibition of the Wnt/beta-catenin pathway increased YAP1 mRNA expression. siYAP1 increased CTNNB1/beta-catenin expression and nuclear staining regardless of DLV2, moreover, it decreased cell growth and impaired cell migration. MATERIALS AND METHODS: We assessed in 42 pediatric ACT samples the YAP1 protein expression by immunohistochemistry and mRNA expression by RT-qPCR and analyzed their association with outcome. As controls, we resort 32 fetal and postnatal normal adrenals for IHC and 10 normal adrenal cortices for RT-qPCR. The interaction between YAP1 and the Wnt/beta-catenin pathway was assessed in NCI-H295 adrenocortical cells by inhibiting the TCF/beta-catenin complex and by knocking down YAP1. CONCLUSION: YAP1 overexpression is a marker of poor prognosis for pediatric patients with ACT. In adrenocortical cells, there is a close crosstalk between YAP1 and Wnt/beta-catenin. These data open the possibility of future molecular therapies targeting Hippo/YAP1 signaling to treat advanced ACT.

Bradykinin Impairs and HOE 140 does not Protect Rat Hindlimb Skeletal Muscle Against Tourniquet-induced Reperfusion Injury.

BACKGROUND: Bradykinin (BK) is used in different tissues. Dose-dependent studies have demonstrated that low doses protect against ischemia/reperfusion (I/R) injury while higher doses lead to adverse effects. Although the beneficial effects of BK infusion were observed in myocardium, its role on the I/R impact in skeletal muscle (SM) has not been fully clarified. OBJECTIVE: This study was carried out to evaluate the effects of BK, administered in the hindlimbs of rats subjected to I/R. METHODS: The study design included three experimental groups: Group 1 control (saline), Group 2 (bradykinin), and Group 3 (HOE 140, a BK2 receptor blocker). In all three groups, rats were subjected to hindlimb ischemia for a total of 2 h followed by continuous 4 h of reperfusion with pharmacological interventions. The methods include analysis of enzymes (lactate dehydrogenase-LDH and creatinine phosphokinase-CPK), cell membrane marker of injury (malondialdeyde-MDA), recruitment of neutrophils (myeloperoxidase-MPO), and apoptosis index (immunohistochemistry TUNEL in situ peroxidase dead end). RESULTS: Except for the apoptotic index, all parameters studied were shown to be elevated in the reperfusion group intervened with BK. The blocking of BK2 receptors by HOE 140 did not affect the I/R injury. CONCLUSION: After 2 h of total ischemia, infusion of bradykinin during 4 h of reperfusion, worsened the I/R injury in the hindlimb skeletal muscle.

Ganho de peso, consumo de ração e histologia de órgãos de leitões alimentados com rações contendo baixos níveis de fumonisina B1 / Weight gain, feed consumption and histology of organs from piglets fed rations containing low levels of fumonisin B1

A fumonisina B1 (FB1) é um metabólito secundário produzido principalmente por Fusarium verticilioides em diversos tipos de alimentos, principalmente o milho, o qual constitui a base para composição de rações para várias espécies de animais domésticos. A FB1é particularmente tóxica para suínos, cujas manifestações clínicas são evidentes em animais expostos a altas concentrações de FB1 na ração (em geral, acima de 30mg/kg). No entanto, são escassos os estudos sobre os efeitos da FB1em suínos alimentados com rações contendo baixas concentrações de fumonisinas, as quais são mais prováveis de serem encontradas em condições de campo. O objetivo do estudo foi avaliar os efeitos da exposição de leitões a baixos níveis de FB1 na ração, durante 28 dias, sobre o ganho de peso, consumo de ração, peso relativo de órgãos e aspectos histológicos do baço, fígado, pulmões, rins e coração. Vinte e quatro leitões foram distribuídos em 4 grupos experimentais e alimentados com rações contendo 0mg (controle), 3,0mg, 6,0mg ou 9,0mg FB1/kg de ração. As diferentes dietas não afetaram (P>0,05) o ganho de peso e nem o peso relativo dos órgãos analisados. Não foram constatadas lesões macroscópicas ou histopatológicas no baço, fígado, rins e coração. No entanto, foram observadas lesões histopatológicas nos pulmões de todos os suínos alimentados com rações contaminadas com fumonisinas, indicando que nenhum dos níveis de FB1 usados no experimento poderia ser considerado como seguro para suínos. São necessários novos estudos sobre os mecanismos de ação tóxica da FB1 em suínos, sobretudo em condições de exposição prolongada a baixos níveis de contaminação na ração.

Fumonisin B1 (FB1) is a secondary metabolite produced mainly by Fusarium verticilioides in several types of foods, particularly corn, which is the basis for composition of feed for several domestic animals. FB1 is particularly toxic to pigs, being the clinical manifestations evident in animals exposed to high concentrations of FB1 in the diet (generally above 30mg/kg). However, there are few studies on the effects of FB1 on pigs fed rations containing low concentrations of fumonisin, which are most probably found under field conditions. The aim of the study was to evaluate the effects of a 28-day exposure of piglets to low levels of FB1 in the feed on the weight gain, feed consumption, organ weights and histological aspects of the spleen, liver, lungs, kidneys and heart. Twenty-four pigs were assigned into 4 experimental groups and fed diets containing 0mg (control), 3.0mg, 6.0mg or 9.0mg FB1/kg diet. The different diets did not affect (P>0.05) the weight gain or the weight of organs examined. There were no macroscopic or histological lesions in the spleen, liver, kidneys and heart. However, histological lesions were found in the lungs from all animals fed rations containing fumonisin, hence indicating that none of the FB1 levels used in the experiment could be considered as safe for piglets. Further studies on the mechanisms of toxic action of FB1 in pigs are needed, particularly under conditions of prolonged exposure to low contamination levels in the diet.

Interleukin-6 and C-reactive protein are overexpressed in the liver of perinatal deaths diagnosed with fetal inflammatory response syndrome.

Anatomopathologic studies have failed to define the fetal inflammatory response syndrome (FIRS) as a cause of fetal death. Here, liver fragments of perinatal autopsies were collected at a university hospital from 1990 to 2009 and classified according to the cause of death, perinatal stress, and gestational age (GA) of the fetus. IL-6, TNF-α, and C-reactive protein (CRP) expression were immunostained, respectively, with primary antibody. Cases with congenital malformation, ascending infection, and perinatal anoxia showed increased IL-6, CRP, and TNF-α, respectively. Prematures presented higher expression of IL-6 whereas term births showed higher expression of CRP. Cases classified as acute stress presented higher expression of IL-6 and TNF-α and cases with chronic stress presented higher expression of CRP. GA correlated negatively with IL-6 and positively with CRP and TNF-α. Body weight correlated negatively with IL-6 and positively with CRP and TNF-α. Despite the diagnosis of FIRS being clinical and based on serum parameters, the findings in the current study allow the inference of FIRS diagnosis in the autopsied infants, based on an in situ liver analysis of these markers.

The effects of glucose and lipids in steatotic and non-steatotic livers in conditions of partial hepatectomy under ischaemia-reperfusion.

BACKGROUND: Steatosis is a risk factor in partial hepatectomy (PH) under ischaemia-reperfusion (I/R), which is commonly applied in clinical practice to reduce bleeding. Nutritional support strategies, as well as the role of peripheral adipose tissue as energy source for liver regeneration, remain poorly investigated. AIMS: To investigate whether the administration of either glucose or a lipid emulsion could protect steatotic and non-steatotic livers against damage and regenerative failure in an experimental model of PH under I/R. The relevance of peripheral adipose tissue in liver regeneration following surgery is studied. METHODS: Steatotic and non-steatotic rat livers were subjected to surgery and the effects of either glucose or lipid treatment on damage and regeneration, and part of the underlying mechanisms, were investigated. RESULTS: In non-steatotic livers, treatment with lipids or glucose provided the same protection against damage, regeneration failure and ATP drop. Adipose tissue was not required to regenerate non-steatotic livers. In the presence of hepatic steatosis, lipid treatment, but not glucose, protected against damage and regenerative failure by induction of cell cycle, maintenance of ATP levels and elevation of sphingosine-1-phosphate/ceramide ratio and phospholipid levels. Peripheral adipose tissue was required for regenerating the steatotic liver but it was not used as an energy source. CONCLUSION: Lipid treatment in non-steatotic livers provides the same protection as that afforded by glucose in conditions of PH under I/R, whereas the treatment with lipids is preferable to reduce the injurious effects of liver surgery in the presence of steatosis.

Evidence of Renal Infection in Fatal Cases of 2009 Pandemic Influenza A (H1N1).

The 2009 pandemic influenza A (H1N1) caused significant morbidity and mortality. Acute lung injury is the hallmark of the disease, but multiple organ system dysfunction can develop and lead to death. Therefore, we sought to investigate whether there was postmortem evidence of H1N1 presence and virus-induced organ injury in autopsy specimens. Five cases in which patients died of influenza A (H1N1) virus infection were studied. The lungs of all patients showed macroscopic and microscopic findings already described for H1N1 (consolidation, edema, hemorrhage, alveolar damage, hyaline membrane, and inflammation), and H1N1 viruses were present in alveolar cells in immunochemical studies. Acute tubular necrosis was present in all cases, but there was no evidence of direct virus-induced kidney injury. Nevertheless, H1N1 viruses were found in the cytoplasm of glomerular macrophages in the kidneys of 4 patients. Therefore, our data provide strong evidence that H1N1 presence is not restricted to the lungs.

Relationship between plasma cells and hepatic stellate cells in autoimmune hepatitis.

Autoimmune hepatitis is an inflammatory chronic disease of the liver, which frequently results in cirrhosis. The present study aimed to verify the relationship between plasma cells and stellate cells in autoimmune hepatitis. Thirty-three pre-treatment, 11 post-treatment, and 10 normal liver biopsies were reviewed. Sirius Red staining (for semi-quantitative analysis of hepatic fibrosis) and immunohistochemistry were carried out: double staining for smooth muscle α-actin and plasma cell marker (for detection and localization of activated hepatic stellate cells and plasma cells, respectively); and single staining for glial fibrillary acid protein (for detection of hepatic stellate cells). We found an increase in the stellate cell population, mainly with an activated phenotype in autoimmune hepatitis, compared to the control group (liver specimens with no histological evidence of liver disease, obtained from patients undergoing hepatic resection for benign liver mass). A positive significant correlation was observed between stellate cells and scores of fibrosis (measured by Sirius Red) and the number of plasma cells. Additionally, there was a co-localization of plasma cells and activated stellate cells. We also observed a reduction in the number of plasma cells, hepatic stellate cells, and fibrosis in patients who had successfully been treated and had a second liver biopsy post-treatment. Our findings support that the number of plasma cells can be a surrogate marker for the severity of liver disease, reflecting the number of hepatic stellate cells and the amount of fibrosis. It remains to be seen if this is a result of a direct interaction between the plasma cells and hepatic stellate cells or the response to the same stimulus that affects both cellular types.

Slight activation of nuclear factor kappa-B is associated with increased hepatic stellate cell apoptosis in human schistosomal fibrosis.

To investigate the relationship between NF-kappaB activation and hepatic stellate cell (HSC) apoptosis in hepatosplenic schistosomiasis, hepatic biopsies from patients with Schistosoma mansoni-induced periportal fibrosis, hepatitis C virus-induced cirrhosis, and normal liver were submitted to alpha-smooth muscle actin (alpha-SMA) and NF-kappaB p65 immunohistochemistry, as well as to NF-kappaB Southwestern histochemistry and TUNEL assay. The numbers of alpha-SMA-positive cells and NF-kappaB- and NF-kappaB p65-positive HSC nuclei were reduced in schistosomal fibrosis relative to liver cirrhosis. In addition, increased HSC NF-kappaB p65 and TUNEL labeling was observed in schistosomiasis when compared to cirrhosis.These results suggest a possible relationship between the slight activation of the NF-kappaB complex and the increase of apoptotic HSC number in schistosome-induced fibrosis, taking place to a reduced HSC number in schistosomiasis in relation to liver cirrhosis. Therefore, the NF-kappaB pathway may constitute an important down-regulatory mechanism in the pathogenesis of human schistosomiasis mansoni, although further studies are needed to refine the understanding of this process.

Can eccentric arterial plaques alone cause flow stagnation points and favour thrombus incorporation?

We have used an experimental model of aorta stenosis, with a Plexiglas plug, simulating a stable atheromatous plaque that promotes local turbulence and thrombosis. With animal survival of more than 24 h, we followed the partial fibrinolysis of the thrombus as well as its posterior organization and incorporation to the arterial wall as a neointima for up to 30 days. The mushroom plug form permitted the development of recirculation and stasis areas around it, favouring this evolution. Despite noted limitations, this study demonstrates that thrombus incorporation can contribute to plaque extension, as it can promote recirculation and stasis areas.

The lectin KM+ induces corneal epithelial wound healing in rabbits.

Neutrophil influx is essential for corneal regeneration (Gan et al. 1999). KM+, a lectin from Artocarpus integrifolia, induces neutrophil migration (Santos-de-Oliveira et al. 1994). This study aims at investigating a possible effect of KM+ on corneal regeneration in rabbits. A 6.0-mm diameter area of debridement was created on the cornea of both eyes by mechanical scraping. The experimental eyes received drops of KM+ (2.5 microg/ml) every 2 h. The control eyes received buffer. The epithelial wounded areas of the lectin-treated and untreated eyes were stained with fluorescein, photographed and measured. The animals were killed 12 h (group 1, n = 5), 24 h (group 2, n = 10) and 48 h (group 3, n = 5) after the scraping. The corneas were analysed histologically (haematoxylin and eosin and immunostaining for proliferation cell nuclear antigen, p63, vascular endothelial growth factor, c-Met and laminin). No significant differences were found at the epithelial gap between treated and control eyes in the group 1. However, the number of neutrophils in the wounded area was significantly higher in treated eyes in this group. Three control and seven treated eyes were healed completely and only rare neutrophils persisted in the corneal stroma in group 2. No morphological distinction was observed between treated and control eyes in group 3. In treated corneas of group 2, there was an increase in immunostaining of factors involved in corneal healing compared to controls. Thus, topical application of KM+ may facilitate corneal epithelial wound healing in rabbits by means of a mechanism that involves increased influx of neutrophils into the wounded area induced by the lectin.