The hybrid protein BTH2 suppresses allergic airway inflammation in a murine model of HDM-specific immunotherapy.

BACKGROUND: Allergen-specific immunotherapy (AIT) is the only disease-modifying treatment approach to change disease-causing allergens. Hypoallergenic derivatives show promise as potential therapeutics, amongst which BTH2 was designed to induce tolerance against Blomia tropicalis allergy. Our aim was to investigate the hypoallergenicity and immunoregulatory activity of BTH2 in vitro and its therapeutic potential in a mouse model of AIT. METHODS: Recombinant Blo t 5 and Blo t 21 allergens and their hybrid derivatives (BTH1 and BTH2) were expressed and purified. IgE binding capacity was tested by ELISA using sera from Brazilian, Colombian, and Ecuadorian subjects. Secretion of cytokines in supernatants from human cell cultures was measured following stimulation with the four recombinants and controls. The capacity of BTH2 to ameliorate allergic airway inflammation induced by B. tropicalis extract was evaluated in a murine model of AIT. RESULTS: rBlo t 5 and rBlo t 21 were identified as major allergens in Latin American patients, and BTH2 had the lowest IgE binding. In vitro stimulation of human cells induced greater levels of IL-10 and IFN-γ and reduced the secretion of Th2 cytokines. BTH2 ameliorated allergic airway inflammation in B. tropicalis-challenged A/J mice, as evidenced by the histopathological and humoral biomarkers: decreased Th2 cytokines and cellular infiltration (especially eosinophils), lower activity of eosinophil peroxidase, an increase in IgG blocking antibodies and strong reduction of mucus production by goblet cells. CONCLUSIONS: Our study shows that BTH2 represents a promising candidate for the treatment of B. tropicalis allergy with hypoallergenic, immune regulatory and therapeutic properties. Further pre-clinical studies are required in murine models of chronic asthma to further address the efficacy and safety of BTH2 as a vaccine against B. tropicalis-induced allergy.

Hepatoportal sclerosis related to the use of herbals and nutritional supplements. Causality or coincidence?

 Introduction and aim. Non-cirrhotic idiopathic portal hypertension (NCIPH), also known as hepatoportal sclerosis (HPS) is a disease of uncertain etiology. However, various pathophysiological mechanisms has been postulated, including chronic or recurrent infections and exposure to drugs or toxins. In this context, it appears to be of multifactorial etiology or resulting from a portal vascular endothelium aggression. It is important to consider whether the use of dietary supplements and herbs can trigger or contribute to the occurance of HPS. We report a possible association of HPS with the consumption of herbals and / or dietary supplements. MATERIAL AND METHODS: We describe two cases of HPS in patients without known etiology causes associated with this disease. RESULTS: Both patients were females who were diagnosed with HPS following the consumption of Herbalife® products and putative anorexigenic agents in the form herbals infusions. Image-based analysis and the assessment of the histopathological alterations found in the livers confirmed the diagnosis. The histopatological analysis of liver samples from both patients showed portal tracts enlarged by fibrosis with disappearance or reduction in the diameter of the portal vein branches. In many portal tracts, portal veins branches were replaced by aberrant thin-walled fendiforme vessels. The bile ducts and branches of the hepatic artery show normal aspects. CONCLUSION: After the exclusion of other etiologic factors and a comprehensive analysis of clinical history, consumption of Herbalife® products and anorexigenic agents was pointed-out as a puttative predisposing factor for the development of the disease.

Disruption of Splenic Lymphoid Tissue and Plasmacytosis in Canine Visceral Leishmaniasis: Changes in Homing and Survival of Plasma Cells.

Visceral leishmaniasis (VL) is a disease caused by Leishmania infantum, which is transmitted by phlebotomine sandflies. Dogs are the main urban reservoir of this parasite and the disease presents similar characteristics in both humans and dogs. In this paper, we investigated the potential pathways involved in plasma cell replacement of normal cell populations in the spleen, with respect to disease severity in dogs from an endemic area for visceral leishmaniasis. To this end, canine spleen samples were grouped into three categories: TYPE1SC- (non-infected dogs or without active infection with organized white pulp), TYPE1SC+ (infected dogs with organized white pulp) or TYPE3SC+ (infected animals with disorganized white pulp). We analyzed the distribution of different plasma cell isotypes (IgA, IgG and IgM) in the spleen. The expression of cytokines and chemokines involved in plasma cell homing and survival were assessed by real time RT-PCR. Polyclonal B cell activation and hypergammaglobulinemia were also evaluated. The proportion of animals with moderate or intense plasmacytosis was higher in the TYPE3SC+ group than in the other groups (Fisher test, P<0.05). This was mainly due to a higher density of IgG+ plasma cells in the red pulp of this group. The albumin/globulin ratio was lower in the TYPE3SC+ animals than in the TYPE1SC- or TYPE1SC+ animals, which evidences VL-associated dysproteinemia. Interestingly, TYPE3SC+ animals showed increased expression of the BAFF and APRIL cytokines, as well as chemokine CXCL12. Aberrant expression of BAFF, APRIL and CXCL12, together with amplified extrafollicular B cell activation, lead to plasma cell homing and the extended survival of these cells in the splenic red pulp compartment. These changes in the distribution of immunocompetent cells in the spleen may contribute to the progression of VL, and impair the spleen's ability to protect against blood borne pathogens.

Assessment of the circumferential margins, extraprostatic extension and Gleason score in radical prostatectomy specimens: Comparison of a partial embedding method with supplemental total inclusion of peripheral tissues.

BACKGROUND: Recent data suggest that up to 21% of positive circumferential margins (PCM) and 47% of extraprostatic extension (EPE) samples may be missed when partial embedding methods are employed. Kim and colleagues (2009) suggested that total inclusion of the periphery (3mm rim) of the prostate prevented the failure to detect PCM and EPE. DESIGN: Radical prostatectomy specimen (n=148) slides were reviewed after adoption of a protocol that included a ∼3 mm rim of peripheral tissues. We evaluated whether the analysis of supplemental slides of prostate periphery changed margin status, presence of EPE, Gleason score and extent of PCM and EPE. RESULTS: Partial sampling resulted in missing 29% of PCM and 20% of EPE without using data from the supplemental slides of prostate periphery. Changes from focal to extensive disease were found in 11/21 (52%) cases of positive circumferential margins and in 5/13 (38%) cases of extraprostatic extension. Changes in the Gleason score were uncommon. CONCLUSIONS: These results indicate the importance of including all the prostate peripheral tissue for microscopic analysis when partial embedding methods are adopted.

Administration of granulocyte-colony stimulating factor accompanied with a balanced diet improves cardiac function alterations induced by high fat diet in mice.

BACKGROUND/OBJECTIVES: High fat diet (HFD) is a major contributor to the development of obesity and cardiovascular diseases due to the induction of cardiac structural and hemodynamic abnormalities. We used a model of diabetic cardiomyopathy in C57Bl/6 mice fed with a HFD to investigate the effects of granulocyte-colony stimulating factor (G-CSF), a cytokine known for its beneficial effects in the heart, on cardiac anatomical and functional abnormalities associated with obesity and type 2 diabetes. METHODS: Groups of C57Bl/6 mice were fed with standard diet (n = 8) or HFD (n = 16). After 36 weeks, HFD animals were divided into a group treated with G-CSF + standard diet (n = 8) and a vehicle control group + standard diet (n = 8). Cardiac structure and function were assessed by electrocardiography, echocardiography and treadmill tests, in addition to the evaluation of body weight, fasting glicemia, insulin and glucose tolerance at different time points. Histological analyses were performed in the heart tissue. RESULTS: HFD consumption induced metabolic alterations characteristic of type 2 diabetes and obesity, as well as cardiac fibrosis and reduced exercise capacity. Upon returning to a standard diet, obese mice body weight returned to non-obese levels. G-CSF administration accelerated the reduction in of body weight in obese mice. Additionally, G-CSF treatment reduced insulin levels, diminished heart fibrosis, increased exercise capacity and reversed cardiac alterations, including bradycardia, elevated QRS amplitude, augmented P amplitude, increased septal wall thickness, left ventricular posterior thickening and cardiac output reduction. CONCLUSION: Our results indicate that G-CSF administration caused beneficial effects on obesity-associated cardiac impairment.

Penile cancer: impact of age at diagnosis on morphology and prognosis.

PURPOSE: In order to describe epidemiological and pathological features of penile cancer in a high-risk area of Brazil. METHODS: We reviewed the experience (378 patients from 1997 to 2007) of Hospital Aristides Maltez from Salvador, Bahia-the main institution in the state which provides oncologic treatment for penile cancer in the public health system. RESULTS: The present series showed a high rate (17 %) of patients less than 40 years at the time of diagnosis. Cancer-specific death rate in this age group was 19 % (in contrast to 11 and 13 % in the 41-60 and >60 age groups). Squamous cell carcinomas in younger patients were also more likely to exhibit infiltrative growth pattern, perineural invasion, and recurrence. CONCLUSION: Regardless of tumor subtypes, penile carcinoma in Northeastern Brazil had more aggressive features and behavior when presented at younger age. This observation should be confirmed in other large series from endemic areas of penile cancer.

A modified point count method as a practical approach to assess the tumor volume and the percent gland involvement by prostate carcinoma.

This study reports a modified point-count method for quantifying the extent of carcinoma in prostatectomy specimens (n=143), as adapted from Billis et al. (2003) [3]. The prostates were studied as follows: the basal/apical margins were sampled using the cone method. The remainder of the gland was divided into 12 quadrant-shaped regions that were sampled using two slices. Eight equidistant points were marked directly on the coverslip over each fragment. The points inside the tumoral areas were counted and expressed as both the percentage of prostate gland involvement by carcinoma (PGI) and the tumor volume (TV). A significant correlation between the preoperative PSA levels and each of the three quantitative estimations were observed, with improved correlations with the PGI and TV values obtained using the point-count method (viz. number of slices involved (NSI) (r=0.32), PGI (r=0.39) and TV (r=0.44)). With the data sets stratified into three categories, all three methods correlated with multiple parameters, including Gleason scores ≥7, primary Gleason scores ≥4, perineural/angiolymphatic invasion, extraprostatic extension, seminal vesicle invasion and positive margins. All three quantitative methods were associated with morphologic features of tumor progression. The results obtained using this modified point-count method correlate more strongly with preoperative PSA levels.

Activity of antimalarial drugs in vitro and in a murine model of cutaneous leishmaniasis.

The currently used treatments for leishmaniasis, a neglected parasitic disease, are associated with several side effects, high cost and resistance of the Leishmania parasites. Here we evaluated in vitro and in vivo the antileishmanial activity of five antimalarial drugs against Leishmania amazonensis. Mefloquine was effective against promastigotes in axenic cultures and showed an IC50 (concentration giving half-maximal inhibition) value of 8.4±0.7 µM. In addition, mefloquine, chloroquine and hydroxychloroquine were active against intracellular amastigotes in macrophage-infected cultures, presenting IC50 values of 1.56±0.19 µM, 0.78±0.08 µM and 0.67±0.12 µM, respectively. The ultrastructural analysis of chloroquine- or mefloquine-treated amastigotes showed an accumulation of multivesicular bodies in the cytoplasm of the parasite, suggesting endocytic pathway impairment, in addition to the formation of myelin-like figures and enlargement of the Golgi cisternae. CBA mice were infected with L. amazonensis in the ear dermis, and treated by oral and/or topical routes with chloroquine and mefloquine. Treatment of L. amazonensis-infected mice with chloroquine by the oral route reduced lesion size, which was associated with a decrease in the number of parasites in the ear, as well as the parasite burden in the draining lymph nodes. In contrast, mefloquine administration by both routes decreased the lesion size in infected mice without causing a reduction in parasite burden. Our results revealed a promising antileishmanial effect of chloroquine and suggest its use in cutaneous leishmaniasis treatment.

17-AAG kills intracellular Leishmania amazonensis while reducing inflammatory responses in infected macrophages.

BACKGROUND: Leishmaniasis is a neglected endemic disease with a broad spectrum of clinical manifestations. Pentavalent antimonials have been the treatment of choice for the past 70 years and, due to the emergence of resistant cases, the efficacy of these drugs has come under scrutiny. Second-line drugs are less efficacious, cause a range of side effects and can be costly. The formulation of new generations of drugs, especially in developing countries, has become mandatory. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the anti-leishmanial effect of 17-(allylamino)-17-demethoxygeldanamycin (17-AAG), an HSP90 inhibitor, in vitro. This inhibitor is currently in clinical trials for cancer treatment; however, its effects against intracellular Leishmania remain untested. Macrophages infected with L. amazonensis were treated with 17-AAG (25-500 nM) and parasite load was quantified using optical microscopy. Parasite load declined in 17-AAG-treated macrophages in a dose- and time-dependent manner. Intracellular parasite death became irreversible after 4 h of treatment with 17-AAG, and occurred independent of nitric oxide (NO) and superoxide (O(2) (-)) production. Additionally, intracellular parasite viability was severely reduced after 48 h of treatment. Interestingly, treatment with 17-AAG reduced pro-inflammatory mediator production, including TNF-α, IL-6 and MCP-1, yet IL-12 remained unaffected. Electron microscopy revealed morphological alterations, such as double-membrane vacuoles and myelin figures at 24 and 48 h after 17-AAG treatment. CONCLUSIONS/SIGNIFICANCE: The HSP90 inhibitor, 17-AAG, possesses high potency under low dosage and reduces both pro-inflammatory and oxidative molecule production. Therefore, further studies are warranted to investigate this inhibitor's potential in the development of new generations of anti-leishmanials.

Transplantation of bone marrow cells decreases tumor necrosis factor-α production and blood-brain barrier permeability and improves survival in a mouse model of acetaminophen-induced acute liver disease.

BACKGROUND AIMS: Acute liver failure (ALF), although rare, remains a rapidly progressive and frequently fatal condition. Acetaminophen (APAP) poisoning induces a massive hepatic necrosis and often leads to death as a result of cerebral edema. Cell-based therapies are currently being investigated for liver injuries. We evaluated the therapeutic potential of transplantation of bone marrow mononuclear cells (BMC) in a mouse model of acute liver injury. METHODS: ALF was induced in C57Bl/6 mice submitted to an alcoholic diet followed by fasting and injection of APAP. Mice were transplanted with 10(7) BMC obtained from enhanced green fluorescent protein (GFP) transgenic mice. RESULTS: BMC transplantation caused a significant reduction in APAP-induced mortality. However, no significant differences in serum aminotransferase concentrations, extension of liver necrosis, number of inflammatory cells and levels of cytokines in the liver were found when BMC- and saline-injected groups were compared. Moreover, recruitment of transplanted cells to the liver was very low and no donor-derived hepatocytes were observed. Mice submitted to BMC therapy had some protection against disruption of the blood-brain barrier, despite their hyperammonemia, and serum metalloproteinase (MMP)-9 activity similar to the saline-injected group. Tumor necrosis factor (TNF)-α concentrations were decreased in the serum of BMC-treated mice. This reduction was associated with an early increase in interleukin (IL)-10 mRNA expression in the spleen and bone marrow after BMC treatment. CONCLUSIONS: BMC transplantation protects mice submitted to high doses of APAP and is a potential candidate for ALF treatment, probably via an immunomodulatory effect on TNF-α production.

Renal epithelioid angiomyolipoma with epithelial cysts: demonstration of Melan A and HMB45 positivity in the cystic epithelial lining.

Renal angiomyolipoma (AML) may present as rare variants such as epithelioid and AML with epithelial cysts posing difficulties for the diagnosis to the surgical pathologist. We report a case of a 46-year-old male patient presenting a 5-cm solid tumor in the lower pole of the left kidney, with cystic changes at cut surface. The tumor exhibited 95% of epithelioid cells with atypical nuclei. A small focus of typical AML was observed. The immunoprofile of tumor cells was classical of AML including expression of melanocytic markers such as HMB45 and Melan A. We report the immunohistochemical study of the cystic component in an epithelioid AML. In contrast to the immunoreactivity reported in typical AML, the present case shows obvious expression of melanocytic markers in the cystic epithelial lining. This is strong evidence that these cysts are neoplastic and derived from AML, rather than entrapped native collecting duct epithelium.

Reduction of galectin-3 expression and liver fibrosis after cell therapy in a mouse model of cirrhosis.

BACKGROUND AIMS: Cirrhosis, end-stage liver disease, is caused by different mechanisms of injury, associated with persistent inflammation. Galectin-3 is an important regulator of fibrosis that links chronic inflammation to fibrogenesis. We investigated the role of bone marrow cell (BMC) transplantation in chronic inflammation and hepatic fibrosis. METHODS: Liver cirrhosis was induced by administration of carbon tetrachloride and ethanol to wild-type C57BL/6 or bone marrow chimeric mice. Bone marrow chimeras were generated by lethal irradiation and transplantation with BMC obtained from green fluorescent protein (GFP(+) )donors. Wild-type cirrhotic mice were transplanted with BMC without irradiation. Livers from chimeras and cirrhotic transplanted mice were obtained for evaluation of inflammation, fibrosis and regulatory factors [galectin-3, matrix metallopeptidase (MMP)-9, tissue inhibitor of metalloproteinase (TIMP)-1 and transforming growth factor (TGF)-ß]. RESULTS: The development of cirrhosis was associated with increased expression of galectin-3 by F4/80(+) cells and intense migration of BMC to the liver. Furthermore, when transplanted after the establishment of cirrhosis, BMC also migrated to the liver and localized within the fibrous septa. Two months after BMC therapy, cirrhotic mice had a significant reduction in liver fibrosis and expression of type I collagen. We did not find any difference in levels of TGF-ß, TIMP-1 and MMP-9 between saline and BMC groups. However, the numbers of inflammatory cells, phagocytes and galectin-3(+) cells were markedly lower in the livers of cirrhotic mice treated with BMC. CONCLUSIONS: Our results demonstrate an important role for BMC in the regulation of liver fibrosis and that transplantation of BMC can accelerate fibrosis regression through modulatory mechanisms.

Chemokines and chemokine receptors coordinate the inflammatory immune response in human cutaneous leishmaniasis.

Cutaneous leishmaniasis (CL) includes different clinical manifestations displaying diverse intensities of dermal inflammatory infiltrate. Diffuse CL (DCL) cases are hyporesponsive, and lesions show very few lymphocytes and a predominance of macrophages. In contrast, localized CL (LCL) cases are responsive to leishmanial antigen, and lesions exhibit granulocytes and mononuclear cell infiltration in the early phases, changing to a pattern with numerous lymphocytes and macrophages later in the lesion. Therefore, different chemokines may affect the predominance of cell infiltration in distinct clinical manifestations. In lesions from LCL patients, we examined by flow cytometry the presence of different chemokines and their receptors in T cells, and we verified a higher expression of CXCR3 in the early stages of LCL (less than 30 days of infection) and a higher expression of CCR4 in the late stages of disease (more than 60 days of infection). We also observed a higher frequency of T cells producing IL-10 in the late stage of LCL. Using immunohistochemistry, we observed a higher expression of CCL7, CCL17 in lesions from late LCL, as well as CCR4 suggesting a preferential recruitment of regulatory T cells in the late LCL. Comparing lesions from LCL and DCL patients, we observed a higher frequency of CCL7 in DCL lesions. These results point out the importance of the chemokines, defining the different types of cells recruited to the site of the infection, which could be related to the outcome of infection as well as the clinical form observed.

Nonalcoholic fatty liver disease associated with obstructive sleep apnea: just a coincidence?

BACKGROUND: Obesity is associated with obstructive sleep apnea (OSA) and nonalcoholic fatty liver disease (NAFLD). It has been shown that OSA could be an independent risk factor for NAFLD. OSA could cause not only insulin resistance but worse NAFLD through nocturnal hypoxemia. This study aimed to evaluate the frequency of OSA and NAFLD in obese patients and the relationship between OSA, insulin resistance, and severity of steatohepatitis (nonalcoholic steatohepatitis (NASH)). METHODS: Forty obese patients submitted to bariatric surgery were evaluated. Sleep studies, fasting blood glucose, serum insulin, homeostasis model assessment (HOMA-IR), and liver enzymes were measured. Liver biopsies were evaluated for features of NAFLD including degrees of steatosis, inflammation, cellular ballooning, and fibrosis. NASH was diagnosed in those with steatosis + ballooning or steatosis + fibrosis. The diagnosis of OSA was based on an apnea/hypopnea index (AHI) ≥ 5 events/hours. RESULTS: OSA was present in 32 (80.0%), NAFLD in 33 (82.5%), and NASH in 32 (80.0%) patients. Patients with AHI ≥ 15 ev/h had higher serum insulin levels (30.0 ± 12.8 vs. 22.6 ± 17.3 µU/ml; p = 0.015) and HOMA-IR (7.5 ± 4.0 vs. 5.4 ± 4.1; p = 0.016) when compared with those with AHI < 15 ev/h, but no association was found between AHI and NASH (81.0% vs. 78.9%; p = 1.000) or oxihemoglobin desaturation <84% and NASH (81.2% vs. 70.8%; p = 0.709) when these groups were compared. CONCLUSIONS: Obese patients had elevated OSA and NAFLD frequencies. OSA was associated with insulin resistance but not with the severity of NASH.

Current status of stem cell therapy for liver diseases.

Liver failure is one of the main causes of death worldwide and is a growing health problem. Since the discovery of stem cell populations capable of differentiating into specialized cell types, including hepatocytes, the possibility of their utilization in the regeneration of the damaged liver has been a focus of intense investigation. A variety of cell types were tested both in vitro and in vivo, but the definition of a more suitable cell preparation for therapeutic use in each type of liver lesions is yet to be determined. Here we review the protocols described for differentiation of stem cells into hepatocytes, the results of cell therapy in animal models of liver diseases, as well as the available data of the clinical trials in patients with advanced chronic liver disease.

Intramitochondrial crystalline inclusions in nonalcoholic steatohepatitis.

UNLABELLED: Mitochondrial dysfunction is an important element in the pathogenesis of nonalcoholic steatohepatitis (NASH). Intramitochondrial crystals (IMCs) are a well-documented morphological abnormality seen on transmission electron microscopy in this disease. It has been suggested that IMCs consist of phospholipids, but their exact composition remain uncertain many years after their discovery. Micellar phase transitions of phospholipid bilayers is a well-known but little-studied phenomenon in living systems. Its presence in the mitochondria of NASH would offer significant insight into the disease with possible therapeutic implications. We postulated that intramitochondrial disturbances in NASH are sufficient to produce such transitions and that their detection in fresh biopsies would therefore be a dynamic process. To test this, we performed a blinded, prospective analysis of fresh liver biopsy samples immediately fixed under different conditions. Quantitative transmission electron microscopy morphometry, performed by systematically counting total mitochondria and IMCs within areas of uniform dimension, showed a stepwise decline in IMCs with cooler fixation temperature in each subject studied. Randomization testing (Monte Carlo resampling) confirmed that the detection of IMCs was strongly dependent on fixation temperature (P < 0.0001). CONCLUSION: These results indicate that the intramitochondrial crystals characteristic of NASH are highly dynamic and unstable structures. The findings offer the strongest support yet for their origin in micellar phase transitions. We speculate that such transitions result from microenvironmental changes within the mitochondria and carry therapeutic implications, especially in regard to dietary manipulations of mitochondrial lipid composition.

Nonalcoholic fatty liver disease in severely obese individuals: the influence of bariatric surgery.

BACKGROUND: Obesity is the most frequent risk factor associated with NAFLD, and bariatric surgery (BAS) is traditionally indicated for the treatment of severely obese individuals. Here, we discuss the behavior and prognosis of this liver disease following post-surgical weight loss. AIM: To evaluate the influence of the BAS on the clinical and biochemical parameters of NAFLD in severely obese patients. METHODOLOGY: An intervention study included obese individuals (BMI > or = 35kg/m2), who had been submitted to liver biopsy during BAS and had NAFLD. HAIR (hypertension, ALT and insulin resistance and BAAT (BMI, ALT, age and triglycerides) scores and FLI (Fatty Liver Index) were used to compare the patients at the time of surgery, and 12-30 months following weight loss. RESULTS: From October 2004 to September 2007, 122 patients were diagnosed with NAFLD, 40 of whom agreed to participate in the study. The mean age was 37.7 +/- 12.5 years, 60% were women and 80% had steatohepatitis (NASH) with fibrosis upon analysis of the liver biopsy performed during BAS. Mean weight loss was 46.0 +/- 2.0 kg. After 21 +/- 5.8 months of follow-up, a significant improvement was found in all the variables analyzed (79.3% according to the HAIR scores, 95.2% as measured by the BAAT score and 72.5% by the FLI. CONCLUSION: The results suggest that treatment of obesity by bariatric surgery may influence the prognosis of NAFLD. In addition to weight loss, we observed improvement in the clinical and biochemical parameters related to NAFLD, such as anthropometrics index, hypertension, aminotransferases, triglycerides and insulin resistance.

Fatty liver disease in severe obese patients: diagnostic value of abdominal ultrasound.

AIM: To evaluate the sensitivity and specificity of abdominal ultrasound (US) for the diagnosis of hepatic steatosis in severe obese subjects and its relation to histological grade of steatosis. METHODS: A consecutive series of obese patients, who underwent bariatric surgery from October 2004 to May 2005, was selected. Ultrasonography was performed in all patients as part of routine preoperative time and an intraoperative wedge biopsy was obtained at the beginning of the bariatric surgery. The US and histological findings of steatosis were compared, considering histology as the gold standard. RESULTS: The study included 105 patients. The mean age was 37.2+/-10.6 years and 75.2% were female. The histological prevalence of steatosis was 89.5%. The sensitivity and specificity of US in the diagnosis of hepatic steatosis were, respectively, 64.9% (95% CI: 54.9-74.3) and 90.9% (95% CI: 57.1-99.5). The positive predictive value and negative predictive value were, respectively, 98.4% (95% CI: 90.2-99.9) and 23.3% (95% CI: 12.3-39.0). The presence of steatosis on US was associated to advanced grades of steatosis on histology (P=0.016). CONCLUSION: Preoperative abdominal US in our series has not shown to be an accurate method for the diagnosis of hepatic steatosis in severe obese patients. Until another non-invasive method demonstrates better sensitivity and specificity values, histological evaluation may be recommended to these patients undergoing bariatric surgery.

Virological and histological re-evaluation of Labrea hepatitis.

BACKGROUND: a peculiar form of fulminant hepatitis known as Labrea hepatitis, probably related to hepatitis B and D, has been reported in Brazilian Amazon as early as the 1930s. METHODS: we reviewed the postmortem liver biopsies of 9 patients with Labrea Hepatitis. Immunostaining for HBV and HDV antigens were performed. RESULTS: we found several important characteristics in the liver tissues: 1) moderate hepatocellular necro-inflammation, 2) hepatocellular ballooning, 3) ballooned hepatocytes with fat droplets surrounding the nucleus (morula-like cells or spongiocytes), 4) mild to moderate necrosis and/or mild portoseptal fibrosis. Hepatitis B surface antigen (HBsAg) was identified in 7 of the 9 cases and was concentrated in the Morula-like cells. Hepatitis B core antigen (HBcAg) was present in 5 cases, mostly in the hepatocyte's nucleous. The hepatitis D virus antigen (HDV Ag) was present in 5 cases, mostly in the cytoplasm and concentrated in the Morula-like cells. CONCLUSION: labrea hepatitis is a fatal disease mostly affecting isolated communities in the Amazon. Evidence implicates HBV and HDV in the etiology of this disease, but this hypothesis needs to be confirmed with genotyping and sequencing research on HBV DNA and HDV RNA extracted from the liver and sera of these patients.

Peripheral blood mononuclear cell supernatants from asymptomatic dogs immunized and experimentally challenged with Leishmania chagasi can stimulate canine macrophages to reduce infection in vitro.

Leishmania chagasi is the causative agent of visceral leishmaniasis in both humans and dogs in the New World. The dog is the main domestic reservoir and its infection displays different clinical presentations, from asymptomatic to severe disease. Macrophages play an important role in the control of Leishmania infection. Although it is not an area of intense study, some data suggest a role for canine macrophages in parasite killing by a NO-dependent mechanism. It has been proposed that control of human disease could be possible with the development of an effective vaccine against canine visceral leishmaniasis. Development of a rapid in vitro test to predict animal responses to Leishmania infection or vaccination should be helpful. In this study, an in vitro model was established to test whether peripheral blood mononuclear cell (PBMC) supernatants from dogs immunized with promastigote lysates and infected with L. chagasi promastigotes could stimulate macrophages from healthy dogs in order to control parasite infection. PBMC from a majority of the immunized and experimentally infected dogs expressed IFN-gamma mRNA and secreted IFN-gamma when stimulated with soluble L. chagasi antigen (SLA) in vitro. Additionally, the supernatants from stimulated PBMC were able to reduce the percentage of infected donor macrophages. The results also indicate that parasite killing in this system is dependent on NO, since aminoguanidine (AMG) reversed this effect. This in vitro test appears to be useful for screening animal responses to parasite inoculation as well as studying the lymphocyte effector mechanisms involved in pathogen killing by canine macrophages.