Enteropathogenic Escherichia coli modulates the virulence and pathogenicity of Entamoeba dispar.

Amoebiasis is a disease caused by Entamoeba histolytica, affecting the large intestine of humans and occasionally leading to extra-intestinal lesions. Entamoeba dispar is another amoeba species considered commensal, although it has been identified in patients presenting with dysenteric and nondysenteric colitis, as well as amoebic liver abscess. Amoebic virulence factors are essential for the invasion and development of lesions. There is evidence showing that the association of enterobacteria with trophozoites contributes to increased gene expression of amoebic virulence factors. Enteropathogenic Escherichia coli is an important bacterium causing diarrhea, with high incidence rates in the world population, allowing it to interact with Entamoeba sp. in the same host. In this context, this study aims to evaluate the influence of enteropathogenic Escherichia coli on ACFN and ADO Entamoeba dispar strains by quantifying the gene expression of virulence factors, including galactose/N-acetyl-D-galactosamine-binding lectin, cysteine proteinase 2, and amoebapores A and C. Additionally, the study assesses the progression and morphological aspect of amoebic liver abscess and the profile of inflammatory cells. Our results demonstrated that the interaction between EPEC and ACFN Entamoeba dispar strains was able to increase the gene expression of virulence factors, as well as the lesion area and the activity of the inflammatory infiltrate. However, the association with the ADO strain did not influence the gene expression of virulence factors. Together, our findings indicate that the interaction between EPEC, ACFN, and ADO Entamoeba dispar strains resulted in differences in vitro and in vivo gene expression of Gal/GalNAc-binding lectin and CP2, in enzymatic activities of MPO, NAG, and EPO, and consequently, in the ability to cause lesions.

Co-infection by Salmonella enterica subsp. Enterica serovar typhimurium and Entamoeba dispar pathogenic strains enhances colitis and the expression of amoebic virulence factors.

Amebiasis is the most severe protozoan infection affecting the human intestine, and the second leading cause of death among parasitic diseases. The mechanisms of amoebic virulence factors acquisition are poorly understood, and there are few studies showing the interaction between Entamoeba dispar and bacteria. Salmonella enterica subsp. enterica serovar typhimurium is also a common cause of gastroenteritis in humans. Considering the high rates of amebiasis and salmonellosis, it is possible that these diseases may co-exist in the human intestine, leading to co-infection. Due to the scarcity of studies showing the influence of enteropathogenic bacteria on amoebic virulence, our research group proposed to evaluate the impact of S. typhimurium on E. dispar trophozoites. We assessed whether co-infection of S. typhimurium and E. dispar can change the progression of amoebic colitis, and the inflammatory response profile in the caecum mucosa, using a co-infection experimental model in rats. In vitro assays was used to investigate whether S. typhimurium induces changes in amoebic virulence phenotype. In the present work, we found that S. typhimurium co-infection exacerbates amoebic colitis and intestinal inflammation. The in vitro association of S. typhimurium and E. dispar trophozoites contributed to increase the expression of amoebic virulence factors. Also, we demonstrated, for the first time, the cysteine proteinase 5 expression in E. dispar MCR, VEJ and ADO strains, isolated in Brazil. Together, our results show that S. typhimurium and E. dispar co-infection worsens amoebic colitis, possibly by increasing the expression of amoebic virulence factors.

Chlorinated metronidazole as a promising alternative for treating trichomoniasis.

Trichomoniasis is the most common non-viral, sexually transmitted infection affecting humans worldwide. The main treatment for trichomoniasis is metronidazole (MTZ). However, adverse effects and reports of resistance have stimulated the development of therapeutic alternatives. The ease of manipulation of the side chains of MTZ coupled with its safety makes this molecule attractive for the development of new drugs. In this context, we evaluated the activity of the chlorinated MTZ derivative, MTZ-Cl, on sensitive and resistant strains of Trichomonas vaginalis. MTZ-Cl presented a remarkable activity against both sensitive and resistant strains. In vitro and in vivo toxicity assays indicated that the new molecule is safe for future clinical trials. Furthermore, we noticed different rates of free radical production between the sensitive and resistant strains. MTZ-Cl induced a higher release of nitric oxide (NO, ~ 9000 a.u.) by both sensitive and resistant strains. However, the sensitive strain produced a greater amount of H2O2 (~ 1,800,000 a.u.) and superoxide radicals (~ 350,000 a.u.) in the presence of MTZ. In the resistant strain, production of these radicals was more prominent when MTZ-Cl was used. Collectively, these results suggest that NO is an important molecule in the trichomonacidal activity against resistant and sensitive strains, suggesting an alternative pathway for MTZ-Cl activation. We highlight the high trichomonacidal potential of MTZ-Cl, improving the effectiveness of treatment and reducing side effects. In addition, MTZ-Cl is derived from a well-established drug on the world market that presents low toxicity to human cells, suggesting its safety to proceed with future clinical trials.

Human colostrum action against Giardia lamblia infection influenced by hormones and advanced maternal age.

Children are more susceptible to Giardia lamblia infection. Cells and hormones contained in human colostrum have an immunoprotective action against giardiasis, but the effects of advanced maternal age on these components are poorly understood. This study analyzed the colostrum of older women to determine melatonin and cortisol levels besides the participation of these hormones on the functional activity of phagocytes against G. lamblia. Colostrum samples were collected from younger (18 to 35 years old) and older (over 36 years old) lactating women. Colostrum samples were subjected to melatonin and cortisol determination, immunophenotyping, quantification of superoxide release, and assessment of phagocytic rate and microbicidal activity of phagocytes treated with hormones and in the presence of G. lamblia. Colostrum from mothers of advanced age contained higher melatonin and cortisol levels and a lower rate of cells expressing CD14+ and CD15+. In the colostru of these older mothers, melatonin increased superoxide release by phagocytes. In both groups, superoxide release by phagocytes treated with cortisol was higher in the presence of G. lamblia. In colostrum from mothers of advanced age, mononuclear (MN) phagocytes treated with melatonin showed higher phagocytosis of G. lamblia and higher microbicidal index. In younger mothers, MN and polymorphonuclear (PMN) colostrum phagocytes exhibited higher rates of G. lamblia elimination when treated with both melatonin and cortisol. In older mothers, cortisol and melatonin regulation for the functional activity of colostrum phagocytes against G. lamblia may represent an additional defense mechanism, relevant for the protection and treatment of parasitic infections in breastfed children.

Detection of IgG Anti-Giardia duodenalis Antibodies in Sera by Indirect Immunofluorescence and Western Blotting Assays.

INTRODUCTION: Serological assays are alternative laboratory tools for the diagnosis of parasitic infections. The aim of this work was to evaluate the performance of the indirect fluorescent antibody test (IFAT) and Western blotting (WB) for the detection of IgG anti-Giardia antibodies in human sera. METHODOLOGY: Sera from individuals infected with Giardia duodenalis, other parasites or non-parasitized were selected for serological assays. Ninety-seven sera were tested by IFAT at 1:20 and 1:40 dilutions and of these, 40 samples were also analyzed by WB. RESULTS: The sensitivity and specificity of the IFAT was 97% and 46.9% at 1:20 sera dilution, and 39.4% and 59.4% at 1:40 sera dilution. The low molecular weight polypeptides fractions of 25 kDa, 27-31 kDa and 45-55 kDa were the most frequently identified by the sera of individuals infected with G. duodenalis, along with low cross-reactivity, presenting an individual sensitivity of 42.8%, 50.0% and 57.1%, and specificity of 83.3%, 83.3% and 91.7%, respectively. The highest overall sensitivity of WB (85.7%) was based on the immunoreactivity of sera with at least one of those proteins. The concordance between the detection of G. duodenalis in feces by microscopy and the WB results was considered substantial (Kappa = 0.61). CONCLUSION: Constant exposure to Giardia infection throughout a lifetime can maintain high levels of specific antibodies in serum, even without active infection. Moreover, proteins found in intestinal amoebas may hinder the serological diagnosis of giardiasis in endemic areas due to cross-reactivity, which can be partially solved using Giardia low molecular weight proteins.

Effect of giardiasis combined with low-protein diet on intestinal absorption of glucose and electrolytes in gerbils.

Studies have shown that symptomatic infection by Giardia lamblia causes acute or chronic diarrhea, dehydration, abdominal pain and malabsorption, leading to undernutrition and weight loss. The aim of the present study was to evaluate the effects of giardiasis and its combination with a low-protein diet on the intestinal absorption of glucose and electrolytes in gerbils. The intestinal absorption of glucose, sodium and potassium was investigated in male gerbils weighing 46-64 g (n≥5). A Tyrode solution containing twice the glucose, sodium and potassium concentration (pH 7.4) was infused through the intestinal loops for 40 min. Glucose absorption was not significantly affected by diet and infection. However, there was a significant increase in sodium absorption in the Giardia-infected group (57.2±6.1, p<0.05) in comparison to the control, low-protein diet and low-protein diet+Giardia-infected groups (8.9±6.5, 2.8±11.1 and 0.8±7.9, respectively; p<0.05). Moreover, potassium was absorbed in the Giardia-infected group (0.45±0.30), while the other groups exhibited potassium secretion. A low-protein diet and Giardia infection had no influence over glucose absorption. However, Giardia infection increased sodium and potassium uptake, suggesting a compensatory mechanism for maintaining homeostasis after likely hypernatremia and hypokalemia caused by the diarrhea that accompanies giardiasis.

Evaluation of Toxicity and Oxidative Stress of 2-Acetylpyridine-N(4)-orthochlorophenyl Thiosemicarbazone.

Thiosemicarbazones are well known for their broad spectrum of action, including antitumoral and antiparasitic activities. Thiosemicarbazones work as chelating binders, reacting with metal ions. The objective of this work was to investigate the in silico, in vitro, and in vivo toxicity and oxidative stress of 2-acetylpyridine-N(4)-orthochlorophenyl thiosemicarbazone (TSC01). The in silico prediction showed good absorption by biological membranes and no theoretical toxicity. Also, the compound did not show cytotoxicity against Hep-G2 and HT-29 cells. In the acute nonclinical toxicological test, the animals treated with TSC01 showed behavioral changes of stimulus of the central nervous system (CNS) at 300 mg/kg. One hour after administration, a dose of 2000 mg/kg caused depressive signs. All changes disappeared after 24 h, with no deaths, which suggest an estimated LD50 of 5000 mg/kg and GSH 5. The group treated with 2000 mg/kg had an increase of water consumption and weight gain in the second week. The biochemical parameters presented no toxicity relevance, and the analysis of oxidative stress in the liver found an increase of lipid peroxidation and nitric oxide. However, histopathological analysis showed organ integrity was maintained without any changes. In conclusion, the results show the low toxicological potential of thiosemicarbazone derivative, indicating future safe use.

Effects of Cytokines IFN-γ and TGF-ß on the Functional Activity of Blood Mononuclear Cells against Giardia lamblia.

BACKGROUND: This study aimed to analyze cultures of mononuclear (MN) cells with Giardia lamblia to determine the levels of the cytokines IFN-γ and TGF-ß and the functional activity of MN cells after incubation with cytokines. METHODS: This study was conducted in 2018 in Barra do Garças, Mato Grosso State, Brazil. Blood samples were collected from 60 healthy volunteer donors to obtain leukocytes. The levels of IFN-γ and TGF-ß were quantified in trophozoite cell culture supernatants. Superoxide release, phagocytosis, microbicidal activity, apoptosis and intracellular calcium release were analyzed. RESULTS: The cytokines evaluated were detected in the culture supernatant of MN cells and G. lamblia. Regardless of the type of cytokine, MN cells increased superoxide release in the presence of G. lamblia. Phagocytosis, microbicidal activity and apoptosis were higher when MN phagocytes were treated with cytokines. The highest microbicidal activity and apoptosis rates were observed in MN cells cultured with TGF-ß. IFN-γ increased the release of intracellular calcium by MN phagocytes. CONCLUSION: Cytokines play a beneficial role in the host by activating MN cells against G. lamblia. In addition, phagocytosis causes G. lamblia death and that the modulation of the functional activity of blood MN phagocytes by cytokines is an alternative mechanism for eliminating G. lamblia.

South American Entamoeba dispar strains produce amoebic liver abscesses with different pathogenicities and evolutionary kinetics.

Amoebiasis is a protozoan disease caused by Entamoeba histolytica, and presents a geographic distribution of worldwide amplitude, high incidence, sometimes accompanied by severe clinical manifestations such as amoebic colitis and Amoebic Liver Abscess (ALA), remaining as a public health problem in developing countries. Entamoeba dispar is another species of amoeba that infects approximately 12% of the world's population, and it has previously been classified as noninvasive. However, E. dispar has already been isolated from patients with symptomatic non-dysenteric colitis, as well as its DNA sequences were detected and genotyped in samples from patients with dysenteric colitis, and patients with ALA, suggesting that this species could also be involved in the development of lesions in the large intestine and liver of human beings. In this context, this study aims to evaluate the ability of isolated strains of Entamoeba dispar in South America to cause liver damage, and to better characterize histopathological findings in 3, 8, 12 and 16 days after infection (DAI). Firstly, we assessed whether trophozoites from MCR, ACFN, ICS, ADO and VEJ E. dispar strains, and EGG Entamoeba histolytica strain differed in their in vitro phagocytosis ability, being related to greater ability to phagocyte with greater virulence. Then, we investigate and characterize histopathological changes present in the liver of mice induced by different strains of E. dispar. Our results demonstrated that trophozoites from E. dispar strains are capable of phagocyting human erythrocytes, but in lower amounts than Entamoeba histolytica. In addition, we described and characterized the lesions in different periods after infection by different E. dispar strains, and identified ACFN as the most pathogenic strain, followed by MCR. The large areas of necrosis produced by the ACFN strain as the eighth DAI, which also show high parasitism, led to 100% mortality. On the other hand, the ICS, ADO and VEJ strains did not produce mortality, and this was correlated with the presence of well-developed chronic granulomatous inflammation, necrosis absorption throughout the infection, and regeneration of the liver parenchyma. The greater pathogenicity of the ACFN strain strongly suggests that this strain could be producing higher levels of virulence factors. As the experimental infection, the heterogeneity of biological behavior of different Entamoeba dispar strains could be involved in the development of undiagnosed human clinical conditions.

Angiostatic activity of human plasminogen fragments is highly dependent on glycosylation.

To assess the importance of carbohydrate moieties to the anti-angiogenic activity of plasminogen fragments, we cloned the fragment corresponding to amino acids Val(79) to Thr(346) (Kint3-4) that presents the three glycosylation sites. The activity of glycosylated and unglycosylated Kint3-4 was tested in murine sponge implant model. We observed a significant decrease in the neovascularization on the sponge after treatment with Kint3-4 by histological examination and determination of the hemoglobin levels. The effects were more intense with the glycosylated than the unglycosylated protein. (99m)Technecium-labeled red blood cells confirmed the inhibition of cell infiltration in the implanted sponge. Studies using melanoma B16F1 implanted in a mouse demonstrated that treatment with glycosylated Kint3-4 (0.15 nmol/48 h) during 14 days suppresses tumor growth by 80%. The vascular endothelial growth factor mRNA levels on the tumor were reduced after treatment. Kint3-4 is a potent plasminogen fragment that has been found to inhibit tumor growth.

Specific IgG and IgA Antibody Reactivities in Sera of Children by Enzyme-Linked Immunoassay and Comparison With Giardia duodenalis Diagnosis in Feces.

BACKGROUND: Giardia duodenalis is conventionally diagnosed in fecal samples using parasitological methods. However, sensitivity is poor when only a single sample is analyzed, due to intermittent excretion of cysts in feces. Alternatively, the serum antibodies to G. duodenalis can be used for parasite diagnosis and epidemiological studies to determine previous exposure. We compared the rate of G. duodenalis infection between serum anti-Giardia IgG and IgA antibodies and fecal examination in Brazilian children. METHODS: Fecal and serum samples were tested from 287 children at a clinical laboratory and from 187 children at daycare centers. Fecal samples were processed using conventional parasitological methods and coproantigen detection for Giardia diagnosis. Serum samples were tested using an in-house ELISA for detection of anti-Giardia IgG and IgA. RESULTS: G. duodenalis was found in 8.2% (N=39) of the 474 children analyzed. The sensitivity and specificity of ELISA were 80.0% and 90.0% for IgG and 80.0% and 83.3% for IgA, respectively. The total positivity rate of anti-Giardia IgG and IgA in the sera was 13.9% (N=66) and 23.6% (N=112). The agreement between the positivity of specific antibodies and the detection of G. duodenalis in feces was moderate for ELISA-IgG, kappa index (95% CI)=0.543 (0.422-0.664), and mild for ELISA-IgA, kappa index (95% CI)=0.283 (0.162-0.404). Among the children infected with other enteroparasites, 11.6% (N=10) and 24.4% (N=21) showed reactivity to anti-Giardia IgG and to IgA, respectively. This cross-reactivity was more frequent in samples from children infected with Endolimax nana and Entamoeba coli. CONCLUSIONS: The higher frequency of specific antibody reactivity compared with G. duodenalis diagnosis in feces could reflect continuous exposure of children to G. duodenalis infection, resulting in long-lasting immunological memory and/or cross-reactivity with other intestinal amoebas.

HQSAR and random forest-based QSAR models for anti-T. vaginalis activities of nitroimidazoles derivatives.

Trichomonas vaginalis is the causative agent of trichomoniasis, a highly prevalent sexually transmitted infection worldwide. Nitroimidazole drugs, such as metronidazole and tinidazole, are the only recommended treatment, but cases of resistance represent at least 5%. In case of resistance or therapeutic failure, posology with higher doses is used, culminating in the increase of the toxic effects of the treatment. In this context, the development of new drugs becomes an eminent necessity. Hologram quantitative structure-activity relationship (HQSAR) models using nitroimidazole derivatives were generated to discover the relationship between the different chemical structures and the activity against cells and the selectivity against susceptible and resistant strains. One model of each strain was chosen for interpretation, both showed good internal coefficient (q2LOO values: 0.607 for susceptible strain and 0.646 for resistant strain subsets) and great values in other internal and external validations metrics. From the contribution of fragments to HQSAR models, several differences between the most and least potent compounds were found: 5-nitroimidazole contributes positively while 4-nitroimidazole negatively. QSAR models employing random forest (RF-QSAR) machine learning technique were also built and a robust model was obtained from resistant strain activity prediction (q2LOO equals to 0.618). The constructed HQSAR and RF-QSAR models were employed to predict the activity of three newly planned nitroimidazole derivatives in the design of new drugs candidates against T. vaginalis strains.

Prevalence of Entamoeba histolytica and other enteral parasitic diseases in the metropolitan region of Belo Horizonte, Brazil. A cross-sectional study.

BACKGROUND: Enteral parasitic diseases are a public health problem in nations with low economic development and in settings with poor sanitation. Amebiasis is the second most frequent form of parasitosis, with a high burden of disease. Knowledge of the prevalence of enteroparasitoses in a given region is useful for planning clinical decision-making. Thus, the aim of this study was to estimate the prevalence of enteral parasitic diseases, especially amebiasis, through analysis on stool samples from public and private laboratories in a metropolitan area in southeastern Brazil. DESIGN AND SETTING: Cross-sectional study conducted in the metropolitan region of Belo Horizonte, Brazil. METHODS: We evaluated 6,289 fecal samples from one private and one public laboratory. The samples were concentrated by means of spontaneous sedimentation, and those that were positive for Entamoeba histolytica or Entamoeba dispar in optical microscopy analyses were processed to obtain deoxyribonucleic acid, with subsequent identification through the polymerase chain reaction. RESULTS: Among the stool samples, 942 (15.0%) had parasitic infections; 73 (1.2%) of these were helminthic infections and 847 (13.5%) were protozoan infections, caused mainly by Escherichia coli (6.0%), Endolimax nana (5.2%) and Giardia lamblia (1.2%). Infections due to Entamoeba histolytica or Entamoeba dispar occurred in 36 samples (0.6%) and the polymerase chain reaction revealed five (13.9%) as Entamoeba histolytica. CONCLUSION: The prevalence of enteral parasitic diseases is high in the metropolitan region of Belo Horizonte, although amebiasis may not be a problem.

Hematological profile in natural progression of giardiasis: kinetics of experimental infection in gerbils.

INTRODUCTION: The clinical manifestations of giardiasis and its impact are harmful to children, and may cause deficits in their physical and cognitive development. The pathogenic mechanisms are usually unknown and the available reports can be controversial. METHODOLOGY: The present study aimed to know, for the first time, the evolution of the hematological profile of the gerbils, experimentally infected with Giardia lamblia, up to the infection's resolution. Hematological variables have been tested. RESULTS: White blood cells have not presented meaningful alterations during the course of the infection. A significant reduction in the number of red blood cells (p = 0.021), in the concentration of hemoglobin (p = 0.029) and in the value of the hematocrit (p = 0.016) has been observed, starting from the second week of infection, ratifying an anemia related to giardiasis. Reduction in the level of serum iron starting from the third week of infection, despite not being significant, could suggest the participation of iron in the anemia. However, the weight of the animals was kept and the hematimetric parameters started to return to the basic values after the parasitological cure without iron reposition. CONCLUSIONS: The outcomes found suggest the idea that not only malabsorption but also other mechanisms such as chronic inflammation may be implicated in iron deficiency anemia in giardiasis and may explain how asymptomatic patients may have anemia without malabsorption. In this context, considering the highlighting character of the anemia in our study, we believe that anemia should be investigated in children with giardiasis. And in the cases of anemia without a definite etiology, giardiasis should also be investigated.

Photodynamic therapy as a new approach to Trichomonas vaginalis inactivation.

The emergence of nitroimidazole resistant isolates has been an aggravating factor in the treatment of trichomoniasis, the most common non-viral sexually transmitted disease in the world. This highlights the importance of new technologies that are safe, effective, and have minor side effects or resistance. Hence, we evaluated the effectiveness of photodynamic therapy on the inactivation of Trichomonas vaginalis in vitro. We used methylene blue as a photosensitizing substance, and a light-emitting diode (LED) for irradiation of metronidazole sensitive and resistant strains. Our results showed that only the presence of light did not interfere with parasite growth; however, methylene blue isolated or associated with light inhibited 31.78% ±â€¯7.18 and 80.21% ±â€¯7.11 of the sensitive strain, respectively, and 31.17% ±â€¯4.23 and 91.13% ±â€¯2.31 of the resistant strain, respectively. The high trichomonicidal activity of the photodynamic therapy, associated with low cost and ease of application, signalize its great therapeutic potential not only when conventional treatment fails, but also routinely in women with trichomoniasis.

Estado nutricional e segurança alimentar de famílias em vulnerabilidade social no município de Contagem, Minas Gerais, 2014 / Nutritional status and food security of socially vulnerable families in the municipality of Contagem, Minas Gerais, 2014

Este é um estudo transversal avaliando estado nutricional e insegurança alimentar em uma comunidade vulnerável de Contagem, região metropolitana de Belo Horizonte. Um total de 273 indivíduos de 67 famílias foram avaliados. Para a avaliação antropométrica, determinou-se o peso, a estatura, o índice de massa corporal, a circunferência da cintura e a razão cintura-estatura. A insegurança alimentar foi analisada por meio da Escala Brasileira de Insegurança Alimentar. As concentrações de colesterol total, triglicerídeos, glicose e albumina sérica também foram determinadas. Das 67 famílias avaliadas, 51% (n = 34) apresentaram insegurança alimentar, sendo 79,4% leve, 17,7% moderada e 2,9% grave. Em crianças e adolescentes, sobrepeso e obesidade foram diagnosticados em 9,3% (n = 4) e 19,5% (n=16), respectivamente. Entre os adultos, 34,1% (n = 42) foram classificados com sobrepeso, 27,6% (n = 34) com obesidade grau I e 59,3% (n = 73) apresentaram risco aumentado de doenças cardiovasculares. Nos idosos, o excesso de peso foi diagnosticado em 44,0% (n = 11) e 80,0% (n = 20) apresentaram risco aumentado para doenças cardiovasculares. Hiperglicemia, hipercolesterolemia e hipertrigliceridemia foram diagnosticadas em 17, 45 e 72% da população, respectivamente. Houve correlação positiva entre os parâmetros antropométricos e bioquímicos, com exceção da albumina e glicose, que apresentaram correlação negativa em crianças e adultos. Nosso estudo confirma o impacto da vulnerabilidade social na ocorrência de elevadas proporções de insegurança alimentar, ocasionando alta prevalência de sobrepeso e obesidade e risco aumentado para desordens cardiovasculares. Além disso, nossos achados endossam o uso de concentrações séricas de albumina como indicador de alterações no metabolismo da glicose.

This is a cross-sectional study evaluating nutritional status and food insecurity in a vulnerable community in Contagem, in the metropolitan region of Belo Horizonte. A total of 273 individuals from 67 families were evaluated. For the anthropometric assessment, weight, height, body mass index, waist circumference, and waist-to-height ratio were determined. Food insecurity was analyzed using the Brazilian Food Insecurity Scale. Total cholesterol, triglycerides, glucose, and serum albumin concentrations were also determined. Of the 67 families evaluated, 51% (n = 34) had food insecurity, of which 79.4% were mild, 17.7% were moderate, and 2.9% were severe. In children and adolescents, overweight and obesity were diagnosed in 9.3% (n = 4) and 19.5% (n = 16), respectively. Among adults, 34.1% (n = 42) were classified as overweight, 27.6% (n = 34) had grade I obesity, and 59.3% (n = 73) had an increased risk of cardiovascular disease. In the elderly, overweight was diagnosed in 44.0% (n = 11), and 80.0% (n = 20) had an increased risk for cardiovascular diseases. Hyperglycemia, hypercholesterolemia, and hypertriglyceridemia were diagnosed in 17, 45, and 72% of the population, respectively. There was a positive correlation between anthropometric and biochemical parameters, with the exception of albumin and glucose, which showed a negative correlation in children and adults. Our study confirms the impact of social vulnerability on the occurrence of high proportions of food insecurity, leading to a high prevalence of overweight and obesity and an increased risk for cardiovascular disorders. Furthermore, our findings support the use of serum albumin concentrations as an indicator of changes in glucose metabolism.

Evaluation of diagnostic methods for the detection of intestinal schistosomiasis in endemic areas with low parasite loads: Saline gradient, Helmintex, Kato-Katz and rapid urine test.

BACKGROUND: In some tropical countries, such as Brazil, schistosomiasis control programs have led to a significant reduction in the prevalence and parasite burden of endemic populations. In this setting, the Kato-Katz technique, as the standard diagnostic method for the diagnosis of Schistosoma mansoni infections, which involves the analysis of two slides from one fecal sample, loses its sensitivity. As a result, a significant number of infected individuals are not detected. The objective of this study was to perform extensive parasitological testing of up to three fecal samples and include a rapid urine test (POC-CCA) in a moderate prevalence area in Northern Minas Gerais, Brazil, and evaluate the performance of each test separately and in combination. METHODS AND FINDINGS: A total of 254 individuals were examined with variants of the standard Kato-Katz technique (up to18 Kato-Katz slides prepared from three fecal samples), a modified Helmintex (30 g of feces), the saline gradient (500 mg of feces), and the POC-CCA methods. We established a reference standard taking into consideration all the positive results in any of the parasitological exams. Evaluation of the parasite burden by two Kato-Katz slides confirmed that most of the individuals harbored a light infection. When additional slides and different parasitological methods were included, the estimated prevalence rose 2.3 times, from 20.4% to 45.9%. The best sensitivity was obtained with the Helmintex method (84%). All parasitological methods readily detected a high or moderate intensity of infection; however, all lost their high sensitivity in the case of low or very low intensity infections. The overall sensitivity of POC-CCA (64.9%) was similar to the six Kato-Katz slides from three fecal samples. However, POC-CCA showed low concordance (κ = 0.34) when compared with the reference standard. CONCLUSIONS: The recommended Kato-Katz method largely underestimated the prevalence of S. mansoni infection. Because the best performance was achieved with a modified Helmintex method, this technique might serve as a more precise reference standard. An extended number of Kato-Katz slides in combination with other parasitological methods or with POC-CCA was able to detect more than 80% of egg-positive individuals; however, the rapid urine test (POC-CCA) produced a considerable percentage of false positive results.

Kinin B1 receptor participates in the control of cardiac function in mice.

The kinins have an important role in control of the cardiovascular system. They have been associated with protective effects in the heart tissue. Kinins act through stimulation of two 7-transmembrane G protein-coupled receptors, denoted B(1) and B(2) receptors. However, the physiological relevance of B(1) receptor in the heart has not been clearly established. Using B(1) kinin receptor gene knock-out mice we tested the hypothesis that the B(1) receptor plays an important role in the control of baseline cardiac function. We examined the functional aspects of the intact heart and also in the isolated cardiomyocytes to study intracellular Ca(2+) cycling by using confocal microscopy and whole-cell voltage clamp techniques. We measured heart rate, diastolic and systolic tension, contraction and relaxation rates and, coronary perfusion pressure. Whole-cell voltage clamp was performed to measure L-type Ca(2+) current (I(Ca,L)). The hearts from B(1)(-/-) mice showed smaller systolic tension. The average values for WT and B(1)(-/-) mice were 2.6+/-0.04 g vs. 1.6+/-0.08 g, respectively. This result can be explained, at least in part, by the decrease in the Ca(2+) transient (3.1+/-0.06 vs. 3.4+/-0.09 for B(1)(-/-) and WT, respectively). There was an increase in I(Ca,L) at depolarized membrane potentials. Interestingly, the inactivation kinetics of I(Ca,L) was statistically different between the groups. The coronary perfusion pressure was higher in the hearts from B(1)(-/-) mice indicating an increase in coronary resistance. This result can be explained by the significant reduction of eNOS (NOS-3) expression in the aorta of B(1)(-/-) mice. Collectively, our results demonstrate that B(1) receptor exerts a fundamental role in the mammalian cardiac function.

Immunocytochemistry Improving the Diagnosis of Trichomonas vaginalis Infections.

The aim of this study was to evaluate the immunocytochemistry (ICC) to diagnose trichomoniasis, particularly asymptomatic infections. By culture serial dilutions, ICC was able to detect 1 trophozoite/mL, while the culture was positive up to 100 trophozoites/mL. The ICC in vivo detection capability was assessed in vaginal secretions of mice experimentally infected and in vaginal swabs from asymptomatic HIV-positive pregnant women compared with culture. All vaginal secretion samples from mice were positive according to both methods. Swabs from fifty-five asymptomatic women were positive in four (7.27%) of them by culture. Beyond these four, another ten (25.45%) women were positive by immunocytochemistry, proving their higher sensitivity (p = 0.002), noticing 3.5 times more positives. ICC had better performance in both successive dilutions as in asymptomatic women, showing higher sensitivity and specificity. In this way, its facility of execution and cost-effectiveness support its practicality, as a routine procedure to diagnose trichomoniasis not only when the parasite load is lower but probably in all clinical scenarios.

Pathogenicity of Entamoeba dispar under xenic and monoxenic cultivation compared to a virulent E. histolytica.

Two xenic isolates and cloned cultures of Entamoeba dispar were submitted to monoxenization using Crithidia fasciculata as the associated organism. Growth in monoxenic cultivation and ability of xenic and monoxenic trophozoites to destroy VERO cells and produce lesions in hamster livers were compared to those of a virulent E. histolytica. Parental and cloned E. dispar under monoxenic cultivation showed a remarkable lower growth than the monoxenic E. histolytica and were avirulent in both in vivo and in vitro tests. When xenically cultured, trophozoites of E. dispar showed a moderate lytic activity against VERO cells (1.5 to 41.8% of destruction) but caused severe hepatic lesions in hamsters as those caused by the virulent E. histolytica (29 to 100% in prevalence and 0.86 to 4.00 in lesion degree). Although E. dispar has not been associated with invasive disease in men, the ability of xenic trophozoites to produce prominent tissue damage in experimental conditions has indicated that some strains have a considerable pathogenic potential when in presence of bacteria.