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Samples of Apis mellifera mellifera venom from different hives in two regions of the Buenos Aires province and its pool were analyzed for their lethal potency, myotoxic, defibrinogenating, hemolytic and inflammatory-edematizing activity and for the histological alterations they produce in the heart, lungs, kidneys, skeletal muscle and liver of mice. In vitro studies focused on the venom's hemolytic activity in different systems and species (horse, man, sheep and rabbit), the cytotoxicity in cellular lines, and on the proteolytic and coagulant activity in plasma and fibrinogen. Hemolytic activity, either observed in vitro or in vivo, showed similar toxicity levels for all samples. Erythrocytes of different species varied in their sensitivity to the venom pool, equines being the most sensitive and sheep the most resistant to direct hemolytic action. Local and systemic myotoxicity was evidenced by either the elevation of serum creatine kinase and/or histopathological lesions, observed in different muscles. All samples caused significant pathological alterations; pulmonary, cardiac, renal and skeletal muscle lesions were substantive and can be related to the pathophysiological mechanisms of envenomation. The venoms from different apiaries and regions of the Buenos Aires province showed very similar toxicological characteristics. These results suggest that severity of envenomation in case of a swarming could therefore be more related to the number of bees than to the differential toxicity of the venom from different regions of the province. This is the first study on the toxicity and toxicological characteristics of Apis mellifera venom in Argentina.

Objectives The aim of the present study was to assess whether there is a relationship between serum lithium concentrations and the magnitude of kidney damage in a preclinical model. Methods Thirty Wistar male rats were randomized into three groups: control group fed ad libitum powered standard diet for 3 months; and experimental groups fed ad libitum the same diet supplemented with 30 or 60 mmol/kg diet for 3 months (LowLi and HighLi groups respectively). Laboratory parameters were assessed at months 1 and 3 and histopathological changes were evaluated after 3 months. Results Serum lithium levels in experimental rats were within therapeutic range used in humans throughout the entire experiment. After 3 months of treatment, lithium levels were statistically higher in HighLi group. Rats of the LowLi group showed dilation of cortical tubules although with similar clearance of creatinine. Rats from the HighLi group had greater histopathological damage in addition to lower creatinine clearance than the other two groups. Conclusions Our study suggests that during long-term treatments, even with serum lithium levels within the therapeutic range used in humans, the risk of kidney damage could increase proportionally to the serum lithium concentration.

Envenomation by scorpions of the genus Tityus is an important public health problem in Argentina, involving near 8000 stings and 2 deaths each year. Treatment for envenomation is the use of specific antivenom and intensive hospital care. Antivenom is produced by the Ministry of Health and freely distributed throughout the country. For antivenom production it is necessary to collect scorpion venom, which is a difficult task because although scorpions can be found in Argentina, they are less abundant than in warmer latitudes. For this reason venom collection constitutes a bottleneck for antivenom production. Although in Argentina several species of Tityus can be found, most of the accidents are caused by Tityus trivittatus, and the venom of this scorpion has historically been the venom used for antivenom production. We analyzed retrospectively 26 pools of telson homogenates (6964 telsons) and 37 pools of milked venom obtained by electrical stimulation (equivalent to 6841 milkings). Lethal potencies of samples from different provinces were very similar, although venom from scorpions of Buenos Aires city showed the lowest potency. The venom obtained by milking (median LD50 12.3 μg), provided batches containing LD50s more potent when compared with the venom obtained from telson homogenates (p < 0.0001). Many batches of telson homogenates (30%) showed lower potencies than acceptable for antivenom production and control. In addition to the study of the venom yield, the records of immunization of horses, the potency of the batches and the protein content of each batch of anti-scorpion antivenom produced were analyzed, comparing those produced using milked venom with those using telson homogenates as immunogens. Batches produced using milked venom required a shorter period of immunization (p < 0.0001), rendered higher neutralizing titers (p 0.0350) and possessed lower protein content (p 0.0092). Results clearly showed that the milking of scorpions is a more efficient tool to obtain venom for antivenom production in comparison to the use of telson homogenates.

Crotalus atrox is one of the species of venomous snakes most commonly found in herpetological collections around the world and it is usually commercialized in the black market. Several collections have specimens but lack of the specific antivenom. We tested the toxicity of venom of adults and young snakes (2 to 3 years old) specimens of C. atrox in captivity and the para-specific neutralization provided by the antivenoms most used in Argentina. The i.p. lethal potency of the venoms were 100(95-105) μg and 43(42-45) μg20g mouse and the indirect hemolytic activity was 7.9 (6.7-9.2) μg and 9.0(8.3-9.9) for adults and juvenile venoms. Despite the adult´s venoms lower lethal potency, these venoms were more difficult to neutralize, around 1.5 ml of antibothropic Antivenom (AB) were necessaries to neutralize 1 mg of venom in contrast to 0.54 ml required to neutralize young´s venoms. The neutralization by the Anticrotalic (AC) antivenom was despicable. The dose of AB required for the neutralization 5.0 LD50 of young snakes was in the range of those required for the neutralization of the specific venoms, nevertheless the dose required to neutralize venom from adults was 6 fold higher. The experiments using 2LD50 as challenge dose, showed similar results. The indirect hemolysis caused by both venoms was similarly neutralized by AB (p

The aim of this study was to evaluate renal damage in animals treated with lithium continuously versus intermittently. Rats were randomized into three groups: control group fed ad libitum powered standard diet for 3 months and two experimental groups, one of them fed ad libitum the same diet or the same diet supplemented with 60 mmol of lithium/kg diet every alternate week, for 3 months and the other fed ad libitum powered standard diet for one and a half month and the same diet supplemented with 60 mmol of lithium/kg diet for the last month and a half. Lithemias in experimental groups were within therapeutic range used in humans. At the end of the protocol, diuresis was higher in experimental groups compared to control group. There was no difference in serum creatinine and creatinine clearance. Both experimental groups showed hypertrophy, hyperplasia, and dilatation of cortical collecting tubules although dilatation was greater in continuous group. Longer studies are necessary to clarify the evolution of renal damage. Our preliminary study shows that histopathological damage associated with the use of lithium occurs during both continuous and intermittent treatment, but it seems to be somewhat greater in the continuous group.

Ischemic postconditioning (PostC) reduces infarct size in healthy experimental models. However, if protective effects of PostC are abolished during early stages of atherosclerotic and if this is related with a disbalance in mitochondrial energetics and alterations in thioredoxin-1 (Trx1) is still unknown. The objectives were to generate a murine high-fat diet (HFD)-fed model that developed in a phenotype consistent with early stages of atherosclerosis to then evaluate whether HFD exposure increased oxidative stress and consequently abolished the cardioprotection conferred by PostC. We used C57/BL6 mice fed with control diet (CD) or HFD for 12 weeks. Isolated mice hearts were subjected to 30 min of ischemia and 120 min of reperfusion (I/R group). For PostC group, after ischemia, six cycles of reperfusion/ischemia were performed (10 s per cycle) at the onset of reperfusion. In CD group, the PostC reduced infarct size (CD-I/R: 52.14 ± 2.8 vs. CD-PostC: 36.58 ± 1.8, P < 0.05) and increased phosphorylation of GSK3β (CD-PostC: 2.341 ± 1.03 vs. CD-Baseline: 0.923 ± 0.41 AUOD, P < 0.05), and this cardioprotection was abolished in HFD-exposed mice. HFD increased hydrogen peroxide levels, produced a shift towards an oxidized intracellular environment (GSSG/GSH 2 ), and increased Trx1 expression with higher fractions of oxidized protein. State 3 mitochondrial oxygen consumption in basal conditions decreased 24% in HFD-exposed mice and PostC improved state 3 values only in CD mice. Cellular redox state and mitochondrial bioenergetics were altered in HFD-exposed mice. We demonstrated that alterations in redox state at early stages of atherosclerosis abolished cardioprotective mechanisms, such as those induced by PostC, even with increased Trx1 levels. Fil: Mazo, Tamara Magali. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina Fil: D'Anunzio, Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina Fil: Zaobornyj, Tamara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina Fil: Perez, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina Fil: Gomez, Anabella. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina Fil: Berg, Gabriela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Barchuk, Magalí. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ossani, Georgina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina Fil: Martinefski, Manuela Romina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina Fil: Tripodi, Valeria Paula. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Tecnología Farmacéutica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Lago, Néstor. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina Fil: Gelpi, Ricardo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad Medicina. Instituto de Bioquímica y Medicina Molecular; Argentina

Summary As global efforts accelerate to implement the Sustainable Development Goals and, in particular, universal health coverage, access to high-quality and timely pathology and laboratory medicine (PALM) services will be needed to support health-care systems that are tasked with achieving these goals. This access will be most challenging to achieve in low-income and middle-income countries (LMICs), which have a disproportionately large share of the global burden of disease but a disproportionately low share of global health-care resources, particularly PALM services. In this first in a Series of three papers on PALM in LMICs, we describe the crucial and central roles of PALM services in the accurate diagnosis and detection of disease, informing prognosis and guiding treatment, contributing to disease screening, public health surveillance and disease registries, and supporting medical-legal systems. We also describe how, even though data are sparse, these services are of both insufficient scope and inadequate quality to play their key role in health-care systems in LMICs. Lastly, we identify four key barriers to the provision of optimal PALM services in resource-limited settings: insufficient human resources or workforce capacity, inadequate education and training, inadequate infrastructure, and insufficient quality, standards, and accreditation.

Subtilase cytotoxin (SubAB) is a member of the AB 5 cytotoxin family and is produced by certain strains of Shiga toxigenic Escherichia coli . The toxin is known to be lethal to mice, but the pathological mechanisms that contribute to Uremic Hemolytic Syndrome (HUS) are poorly understood. In this study we show that intraperitoneal injection of a sublethal dose of SubAB in rats triggers a systemic response, with ascitic fluid accumulation, heart hypertrophy and damage to the liver, colon and kidney. SubAB treated rats presented microalbuminuria 20 days post inoculation. At this time we found disruption of the glomerular filtration barrier and alteration of the protein reabsorption mechanisms of the proximal tubule. In the kidney, SubAB also triggered an epithelial to mesenchymal transition (Wuyts et al., 1996). These findings indicate that apart from direct cytotoxic effects on renal tissues, SubAB causes significant damage to the other organs, with potential consequences for HUS pathogenesis. Importance Uremic Hemolytic Syndrome is an endemic disease in Argentina, with over 400 hundred new cases each year. We have previously described renal effects of Shiga Toxin and its ability to alter renal protein handling. Bearing in mind that Subtilase Cytotoxin is an emerging pathogenic factor, that it is not routinely searched for in patients with HUS, and that to the date its systemic effects have not been fully clarified we decided to study both its systemic effects, and its renal effects to assess whether SubAB could be contributing to pathology seen in children.

Long-term lithium treatment was associated with chronic kidney disease and renal failure although the underlying pathogenic mechanisms are not certainty known. The aim of this study was to evaluate changes in oxidative stress measures as well as renal functional and structural alterations associated with chronic use of lithium in rats. Forty Wistar male rats were randomized into four groups: control groups fed ad libitum powered standard diet for 1 and 3 months and experimental groups fed ad libitum the same diet supplemented with 60 mmol/kg diet for 1 and 3 months. Histopathological changes, laboratory parameters, and oxidative stress measurements were assessed at months 1 and 3. The experimental animals showed alteration of the cortical tubules from the first month of lithium-treatment and a decrease in the glomerular filtration rate and in the glomerular area at the third month. There was an increase in thiobarbituric acid reactive substances and carbonyls, as well as an increase in reduced glutathione, in the kidney of rats exposed to lithium. These changes were evident from the first month of treatment and remained throughout the experiment. Our results suggest that, oxidative stress could be one of the pathogenic mechanisms involved in the structural and functional alterations of the kidney associated with prolonged use of lithium. The study of the pathogenic mechanisms involved in lithium-induced nephropathy is a critical issue for the development of new strategies for prevention and/or early detection. Fil: Ossani, Georgina Paula. Hospital Aleman. Laboratorio de Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Uceda, Ana Margarita. Hospital Aleman. Laboratorio de Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología; Argentina Fil: Acosta, Juan M.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Lago, Néstor Rubén. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología; Argentina Fil: Repetto, Marisa Gabriela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Martino, Diego Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; Argentina Fil: Toblli, Jorge Eduardo. Hospital Aleman. Laboratorio de Medicina Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentina

Renal necrosis can be induced in weanling rats due to choline deficient diet. Menhaden oil has a protective effect against the development of renal necrosis in choline deficient weanling rats. The aim of this work was to determine the effects of menhaden oil in a model of acute kidney injury due to ischemia reperfusion. Wistar rats were divided into two groups and fed vegetable oils or menhaden oil as lipids. Unilateral renal ischemia was performed for 30 minutes and animals were sacrificed 48 hours later. Histopathological examination showed no significant differences between groups. Menhaden oil did not prevent histopathological lesions. Fil: Ossani, Georgina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Hospital Alemán. Laboratorio de Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina Fil: Marcotegui, Ariel R.. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina Fil: Uceda, Ana Margarita. Hospital Alemán. Laboratorio de Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina Fil: Monserrat, Alberto Juan. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina Fil: Lago, Néstor Rubén. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina Fil: Perazzo, Juan C.. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina

Hyaluronan (HA) is the major glycosaminoglycan present in the extracellular matrix. It is produced by some tumours and promotes proliferation, differentiation and migration among others cellular processes. Gestational trophoblastic disease (GTD) is composed by non-tumour entities, such as hydatidiform mole (HM), which is the most common type of GTD and also malignant entities such as choriocarcinoma (CC) and placental site trophoblastic tumour (PSTT), being CC the most aggressive tumour. Although there is a growing understanding of GTD biology, the role of HA in the pathogenesis of this group of diseases remains largely unknown. The aim of this work was to study the role of HA in the pathogenesis of GTD by defining the expression pattern of HA and its receptors CD44 and RHAMM, as well as to determine if HA can modulate proliferation, differentiation and migration of CC cells. Receptors and signalling pathways involved were also analyzed. We demonstrated that HA and RHAMM are differently expressed among GTD entities and even among trophoblast subtypes. We also showed that HA is able to enhance the expression of extravillous trophoblast markers and also to induce migration of JEG-3 cells, the latter mediated by RHAMM as well as PI3K and MAPK pathways. These findings indicate a novel regulatory mechanism for CC cell biology and also contribute to the understanding of GTD pathophysiology. Fil: Mascaró, Marilina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentina Fil: Pibuel, Matías Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentina Fil: Lompardía, Silvina Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentina Fil: Díaz, Mariángeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentina Fil: Zotta, Elsa. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; Argentina Fil: Bianconi, Maria I.. Hospital de Agudos “Carlos G. Durand”; Argentina Fil: Lago, Néstor. Universidad de Buenos Aires. Facultad de Medicina; Argentina Fil: Otero, Silvina. Hospital de Agudos “Carlos G. Durand”; Argentina Fil: Jankilevich, Gustavo. Hospital de Agudos “Carlos G. Durand”; Argentina Fil: Alvarez Carbonetto, Elida M. del C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentina Fil: Hajos, Silvia Elvira. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Estudios de la Inmunidad Humoral Prof. Ricardo A. Margni; Argentina

“Black widow” spiders belong to the genus Latrodectus and are one of the few spiders in the world whose bite can cause severe envenomation in humans and domestic animals. In Argentina, these spiders are distributed throughout the country and are responsible for the highest number of bites by spiders of toxicological sanitary interest. Here, we studied the toxicity and some biochemical and immunochemical characteristics of eighteen venom samples from Latrodectus spiders from eight different provinces of Argentina, and the neutralization of some of these samples by two therapeutic antivenoms used in the country for the treatment of envenomation and by a anti-Latrodectus antivenom prepared against the venom of Latrodectus mactans from Mexico. We observed important toxicity in all the samples studied and a variation in the toxicity of samples, even in those from the same region and province and even in the same Latrodectus species from the same region. The therapeutic antivenoms efficiently neutralized all the venoms studied. Fil: de Roodt, Adolfo Rafael. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina. Universidad de Buenos Aires. Facultad de Medicina; Argentina Fil: Lanari, Laura Cecilia. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina Fil: Laskowicz, Rodrigo Daniel. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina Fil: Costa de Oliveira, Vanessa. Universidad de Buenos Aires. Facultad de Medicina; Argentina Fil: Irazu, Lucia Elvira. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina Fil: Gonzalez, Alda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina Fil: Giambelluca, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina Fil: Nicolai, Néstor. Provincia de Buenos Aires. Ministerio de Salud. Dirección Laboratorio Central de Salud Pública; Argentina Fil: Barragán, Javier Hugo. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina Fil: Ramallo, Leticia. Provincia de Buenos Aires. Ministerio de Salud. Dirección Laboratorio Central de Salud Pública; Argentina Fil: López, Raúl Alfredo. Ministerio de Salud de la Provincia de Catamarca; Argentina Fil: Lopardo, Jorge. Secretaría Salud de la Provincia de Chubut; Argentina Fil: Jensen, Oscar. Secretaría Salud de la Provincia de Chubut; Argentina Fil: Larrieu, Edmundo Juan. Universidad Nacional de Río Negro; Argentina Fil: Calabró, Arnoldo. Ministerio de Salud de la Provincia de Rio Negro; Argentina Fil: Vurcharchuc, Miriam Guadalupe. Ministerio de Salud de la Provincia de Santiago del Estero; Argentina Fil: Lago, Néstor Rubén. Universidad de Buenos Aires. Facultad de Medicina; Argentina Fil: García, Susana Isabel. Ministerio de Salud de la Nación; Argentina Fil: de Titto, Ernesto Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Salud de la Nación; Argentina Fil: Damin, Carlos Fabian. Universidad de Buenos Aires. Facultad de Medicina; Argentina

A phospholipase enzyme was separated by chromatography from the venom of the snake Bothrops (Rhinocerophis) ammodytoides and characterized. The experimentally determined molecular weight was 13,853.65 Da, and the full primary structure was determined by Edman degradation and mass spectrometry analysis. The enzyme contains 122 amino acids residues closely stabilized by 7 disulfide bridges with an isoelectric point of 6.13. Sequence comparison with other known secretory PLA2 shows that the enzyme isolated belongs to the group II, presenting an aspartic acid residue at position 48 (numbered by convention as Asp49) of the active site, and accordingly displaying enzymatic activity. The enzyme corresponds to 3% of the total mass of the venom. The enzyme is mildly toxic to mice. The intravenous LD50 of this phospholipase in CD-1 mice was around 6 μg/g of mouse body weight (more exactly 117 μg/mouse of 20 g) and the minimal mortal dose (MMD) was estimated to be close to 10 μg/g. In contrast, the LD50 of the venom was circa 2 μg/g mouse body weight. Toxicological analyses of the purified enzyme were performed in vitro and in vivo using experimental animals (mice and rats). The enzyme at high doses caused pulmonary congestion, intraperitoneal bleeding, inhibition of clot retraction and muscle tissue alterations with increasing of creatine kinase levels.

Type 1 diabetes (T1D) originates from autoimmune β-cell destruction. IMT504 is an immunomodulatory oligonucleotide that increases mesenchymal stem cells cloning capacity and reverts toxic diabetes in rats. Here we evaluated long-term (20 doses) and short-term (2-6 doses) effects of IMT504 (20 mg/kg/day, sc) in an immunodependent diabetes model: multiple low dose streptozotocin-injected BALB/c mice (40 mg/kg/day, i.p. for 5 consecutive days). We determined blood glucose, glucose tolerance, serum insulin, islet morphology, islet infiltration, serum cytokines, progenitor cell markers, immunomodulatory proteins, proliferation, apoptosis, and islet gene expression. Long-term results: IMT504 reduced glycemia, induced β-cell recovery and impaired islet infiltration. Short-term analysis: IMT504 induced early blood glucose decrease, infiltration inhibition, increased β-cell proliferation and decreased apoptosis, increased islet indoleamine 2,3-dioxygenase (IDO) expression, increased serum tumor necrosis factor and interleukin-6 (IL-6). IMT504 affected islet gene expression: Preproinsulin-2, Proglucagon, Somatostatin, Nestin, Regenerating gene-1 and C-X-C motif ligand-1 cytokine (Cxcl1) increased in islets from diabetic mice and were decreased by IMT504. IMT504 downregulated Platelet endothelial cell adhesion molecule-1 (Pecam1) in islets from control and diabetic mice, whereas it increased Regenerating gene-2 (Reg2) in islets of diabetic mice. The IMT504-induced increase in IL-6 and islet IDO expression, and decreased islet Pecam1 and Cxcl1 mRNA expression could participate in keeping leukocyte infiltration at bay, whereas upregulation of Reg2 may mediate β-cell regeneration. We conclude that IMT504 effectively reversed immunodependent diabetes in mice. Corroboration of these effects in a model of autoimmune diabetes more similar to human T1D could provide promising results for the treatment of this disease. Fil: Bianchi, Maria Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina Fil: Bianchi, Stefania. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina Fil: Hernando Insua, Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. Cesar Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología ; Argentina Fil: Martinez, Leandro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina Fil: Lago, Néstor R.. Universidad de Buenos Aires. Facultad de Medicina; Argentina Fil: Libertun, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina Fil: Chasseing, Norma Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina Fil: Montaner, Alejandro Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. Cesar Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología ; Argentina Fil: Lux, Victoria Adela R.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina

Although the spiders of the genus Phoneutria cause envenomation and their presence has been described in several provinces of the north of Argentina, they are not as common as other spiders of sanitary importance. In the present work, we studied the toxicity of samples of venom of Phoneutria spiders from the provinces of Misiones (where severe envenomation and deaths by Phoneutria have been recorded) and Jujuy (where no deaths have been recorded and severe envenomations are not frequent). To this end, we assessed the lethal potency in mice and guinea pigs and the histopathological alterations caused by both venoms, as well as the neutralization by the commonly used therapeutic antivenom produced by the Butantan Institute in Brazil and by an experimental antivenom developed with venom of P. nigriventer from Misiones. There were no differences in the lethality of the venoms of spiders from both regions. Post mortem examination showed that the heart and lungs were the most affected organs, while important pulmonary edema was seen macroscopically. Histological analysis showed edema, atelectasis, emphysema and cardiac lesion in both experimental models. The antivenoms assayed showed good neutralization of the venoms in the two experimental models. Despite the different geographic origins, the venoms showed similar toxicity and both the experimental antivenom and therapeutic antivenmos were able to neutralize the venoms of Argentinean P. nigriventer.

Mn-Apo is a highly sensitive MRI contrast agent consisting of ca. 1000 manganese atoms entrapped in the inner cavity of apoferritin. Part of the metallic payload is in the form of Mn(2+) ions that endow the nano-sized system with a very high relaxivity that can be exploited to detect hepatocellular carcinoma in mice. Cellular studies showed that Mn-Apo is readily taken up by normal hepatocytes via the ferritin transporting route. Conversely, hepatoma cells (HTC) displayed a markedly reduced ability to entrap Mn-Apo from the culture medium. The i.v. administration of Mn-Apo into C57BL/6 J mice resulted in a marked liver tissue hyperintensity in T(1)-weighted MR image 20 min after injection. When injected into HBV-tg transgenic mice that spontaneously develop hepatocellular carcinoma (HCC), Mn-Apo allowed a clear delineation of healthy liver tissue and tumor lesions as hyperintense and hypointense T(1)-weighted MR images, respectively. Immunohistochemistry analysis correlated Mn-Apo cellular uptake to SCARA5 receptor expression. When the MRI contrast induced by Mn-Apo was compared with that induced by Gd-BOPTA (a commercial contrast agent known to enter mouse hepatocytes through organic anion transporters) it was found that only some of the lesions were detected by both agents while others could only be visualized by one of the two. These results suggest that Mn-Apo may be useful to detect otherwise invisible lesions and that the extent of its uptake directly reports the expression/regulation of SCARA5 receptors. Mn-Apo contrast-enhanced MR images may therefore contribute to improving HCC lesion detection and characterization.

Background We have shown that oligodeoxynucleotide IMT504 improved blood glucose and islet beta-cell content in streptozotocin (STZ)-induced diabetic rats, inducing early expression of progenitor markers. Here we determined the effect of IMT504 on islet infiltration and on immunomodulatory proteins indoleamine 2,3-dioxygenase (IDO) and TNF-α-stimulated gene/protein 6 (TSG-6) in islets of STZ-diabetic rats, at the time of progenitor markers expression. Methods Male rats were i.p. injected with STZ [60 mg/kg body weight (BW)] or citrate buffer (control) (day 1). Starting on day 4, STZ animals were daily treated with saline (STZ-saline) or IMT504 (20 mg/kg BW/day s.c., STZ-IMT504) and killed after two consecutive decreases in blood glucose. Islet area and insulin expression, CD3 (T lymphocytes), CD68 (macrophages), IDO and TSG-6 immunostainings were determined. Islet infiltration was also evaluated by haematoxylin staining. Results STZ-induced diabetes in rats, with an important decrease in islet area was reversed by IMT504. Diabetes development did not involve islet infiltration, determined by haematoxylin and by the absence of significant T lymphocyte and macrophage presence. IMT504 did not induce changes in these parameters. IDO was not expressed in controls; the percentages of IDO-positive islets were very low and similar in STZ-saline and STZ-IMT504. Scarce TSG-6 was expressed in all groups, without significant differences. Conclusions IMT504 improved insulin content but did not alter IDO or TSG-6 staining in islets of STZ-diabetic rats, suggesting that they do not participate in the IMT504-induced repair process. IMT504 did not per se modify leukocyte presence in islets of diabetic rats. Copyright © 2011 John Wiley & Sons, Ltd.

Mitochondrial DNA (mtDNA) copy number plays a key role in the pathophysiology of metabolic syndrome-related phenotypes, but its role in non-alcoholic fatty liver disease (NAFLD) is not well understood. We evaluated the molecular mechanisms that may be involved in the regulation of liver mtDNA content in a high-fat-induced rat model of NAFLD. In particular, we tested the hypothesis that liver mtDNA copy number is associated with liver expression of HIF-1α. Rats were given either standard chow diet (SCD, n= 10) or high-fat diet (HFD, n= 15) for 20 weeks. Subsequently, mtDNA quantification using nuclear DNA (nDNA) as a reference was carried out using real time quantitative PCR. HFD induced a significant increase in liver mtDNA/nDNA ratio, which significantly correlated with the liver triglyceride content (R: 0.29, P < 0.05). The liver mtDNA/nDNA ratio significantly correlated with the hepatic expression of HIF-1α mRNA (R: 0.37, P < 0.001); liver HIF-1α mRNA was significantly higher in the HFD group. In addition, liver cytochrome c oxidase subunit IV isoform 1 (COX4I1) mRNA expression was also positively correlated with liver mtDNA content. The hepatic expression of mRNA of transcriptional factors that regulate mitochondrial biogenesis, including peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and PGC-1β, nuclear respiratory factor-1 (NRF-1), peroxisome proliferator-activated receptor δ and Tfam, was not associated with the liver mtDNA content. Neither hepatocyte apoptosis nor oxidative stress was involved in the HIF-1α-mediated increase in mtDNA copy number. In conclusion, we found that HFD promotes an increase in liver mitochondrial biogenesis in response to hypoxia via HIF-1α, probably to enhance the mitochondrial function as well as to accommodate the metabolic load.

Synthetic oligodeoxynucleotides (ODNs) are currently being evaluated as vaccine adjuvants for inducing protective immunity. As maternal vaccination is becoming increasingly common, the potential risk of vaccine formulation using ODN adjuvants should be warranted. A recent study performed in mice suggests that exposure to CpG motifs during pregnancy could result (although at very high doses as compared to the ones proposed for human vaccination) in fetal loss and morphological defects. PyNTTTTGT ODNs are immunostimulatory ODNs not bearing CpG motifs, which are very efficient vaccine adjuvants. In this report, we analyzed the potential teratogenic effect of its prototype IMT504 in rats. This animal model was chosen because PyNTTTTGT ODNs are barely active in mice. Intraperitoneal injection of IMT504 at a dose of 20 mg/kg (more than 1000 times higher than the one proposed for a vaccine dose in humans) at day 6 of pregnancy did not produce a significant decrease in the mean number of implanted fetuses or in the number of live pups delivered. Neither the fetuses nor the offspring presented malformations. Fil: Hernando Insúa, Andrés. Immunotech; Argentina Fil: Rodriguez, Juan M.. Immunotech; Argentina Fil: Elías, Fernanda. Immunotech; Argentina Fil: Fló, Juan. Immunotech; Argentina Fil: López, Ricardo. Immunotech; Argentina Fil: Franco, Raul. Immunotech; Argentina Fil: Lago, Nestor. Gema Biotech; Argentina Fil: Zorzopulos, Jorge. Immunotech; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Montaner, Alejandro Daniel. Immunotech; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología ; Argentina

In Argentina the scorpions of medical importance belong to the genus Tityus (T.), particularly the species T. trivittatus, the only scorpion whose sting is recognized to be associated with severe human envenoming and death. This genus is distributed from the north of the Patagonian region to the center and some provinces in the north of the country. During the period 2003-2006 four children died following scorpion stings, of which one was certainly and three were probably by T. confluens. In 2006, in the province of Tucumán, a girl died by scorpion envenoming and the scorpion responsible for the death, found in her shoe, was T. confluens. We thus studied the toxicity of venom gland homogenates from T. confluens from the provinces of Jujuy and Catamarca, and of crude venom from specimens from Catamarca and the province of La Rioja. The lethal potencies of the telson homogenates were 7.0 and 18.6 μg/g for Jujuy and Catamarca, respectively, while the lethal potency of the crude venom was 0.7 μg/g. Injected mice showed generalized congestion and hepatic lesions. Pancreatic damage was observed in some animals. Lungs showed congestion and foci of hemorrhage and mild edema. The heart showed injury in the muscular fibers. The venom showed high reactivity against anti-T. trivittatus antivenom and against two anti-T. serrulatus antivenoms. The anti-T. trivittatus antivenom neutralized the lethal activity of T. confluens venom. In addition, the venom reacted very slightly against an anti-Centruroides antivenom. Therefore, the stings of this scorpion must be considered of risk for humans to the same degree as the stings of T. trivittatus Fil: de Roodt, Adolfo Rafael. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina Fil: Lago, Néstor Rubén. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología. Centro de Patología Experimental; Argentina Fil: Salomón, Oscar Daniel. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina. Ministerio de Salud. Instituto Nacional de Medicina Tropical; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina Fil: Laskowicz, Rodrigo Daniel. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina Fil: Neder, Lilia Estela. Universidad Nacional de Jujuy. Instituto de Biología de la Altura; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Jujuy. Universidad Nacional de Jujuy. Centro de Investigaciones y Transferencia de Jujuy; Argentina Fil: López, Raúl Alfredo. Provincia de Catamarca; Argentina Fil: Montero, Teresa Eleonor. Universidad Nacional de Jujuy. Instituto de Biología de la Altura; Argentina Fil: Vega, Valeria del Valle. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina

Portal hypertension is a major complication of human cirrhosis that frequently leads to central nervous system dysfunction. In our study, rats with prehepatic portal hypertension developed hippocampal mitochondrial dysfunction as indicated by decreased respiratory rates, respiratory control and mitochondrial nitric oxide synthase (mtNOS) activity in mitochondria isolated from the whole hippocampus. Succinate-dependent respiratory rates decreased by 29% in controlled state 4 and by 42% in active state 3, and respiratory control diminished by 20%. Portal hypertensive rats showed a decreased mtNOS activity of 46%. Hippocampal mitochondrial dysfunction was associated with ultrastructural damage in the mitochondria of hippocampal astrocytes and endothelial cells. Swollen mitochondria, loss of cristae and rupture of outer and inner membrane was observed in astrocytes and endothelial cells of the blood-brain barrier in parallel with the ammonia gradient. It is concluded that the moderate increase in plasma ammonia that followed portal hypertension was the potential primary cause of the observed alterations.

El IMTE 504 es un oligonucleotido de la linea no CgG, el cual estimula diferentes celulas del sistema inmune. El IMT 504 ha sido testeado en diferentes especies animales: raton, conejo, monos y su actividad fue efectiva en vacunas, leucemia cronico, diabetes, repareacion de tejidos y sepsis . Por lo tanto es de interes evaluar la toxicidad de este oligonucleotido. IMT504 is a non-CpG 24-mer oligodeoxynucleotide (ODN) with immunomodulatory as well as tissue repair activity. IMT504 has been previously proven to be effective in animal models of vaccine potency, chronic lymphocytic leukemia, tissue regeneration, and sepsis. Here, we assessed the safety, including pharmacokinetics and toxicity studies in rats and monkeys, of IMT504 in a single- or repeated-dose administration by the subcutaneous (SC) or intravenous (IV) routes. In rats, the maximum tolerated dose was determined to be 50 mg/ kg when administered SC. Adverse effects at 50 mg/kg were mild and reversible liver injury, revealed as lobular inflammation, focal necrosis, and small changes in the transaminase profile. Dose-dependent splenomegaly and lymphoid hyperplasia, most probably associated with immune stimulation, were commonly observed. Rats and monkeys were also IV injected with a single dose of 10 or 3.5 mg/kg, and no adverse effects were observed. Rats injected IV with 10 mg/kg showed a transient increase in spleen weight, together with a slight increase in the marginal zone of the white pulp and in leukocyte count 2 days post-administration. In monkeys, this dosage caused slight changes in total serum complement and leukocyte count on day 14. No adverse effects were observed at 3.5 mg/kg IV in rats or monkeys. Therefore, this dose was defined as the ‘‘no observed adverse effect level’’ for this route. Furthermore, repeated-dose toxicity studies were performed in these species using 3.5 or 0.35 mg/kg/day IV for 6 weeks. A transient increase in the spleen and liver weight was observed at 3.5 mg/kg/day only in female rats. No changes in clotting time and activation of the alternative complement pathway were observed. The toxicity profile of IMT504 herein reported suggests a dose range in which IMT504 can be used safely in clinical trials. Fil: Franco, Raul. Immunotech S.a.; Argentina Fil: Rodriguez, Juan Manuel. Fundación Pablo Cassara; Argentina Fil: Elias, Fernanda. Immunotech S.a.; Argentina Fil: Hernando Insúa, Andrés. Fundación Pablo Cassara; Argentina Fil: Fló, Juan. Immunotech S.a.; Argentina Fil: López, Ricardo. Immunotech S.a.; Argentina Fil: Nagle, Carlos Alberto. Centro de Educaciones Médicas e Investigación Clínica "Norberto Quirno"; Argentina Fil: Lago, Néstor Rubén. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología; Argentina Fil: Zorzopulos, Jorge. Immunotech S.a.; Argentina Fil: Horn, David. David Horn LlC; Estados Unidos Fil: Montaner, Alejandro Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ciencia y Tecnología "Dr. César Milstein". Fundación Pablo Cassará. Instituto de Ciencia y Tecnología "Dr. César Milstein"; Argentina

Rats with pre-hepatic portal hypertension because of partial portal vein ligation develop minimal hepatic encephalopathy (MHE) with hyperammonemia, impaired blood–brain barrier, mild brain edema, and severe mitochondrial changes in the hippocampus. The aim of this study was to evaluate changes of different neural cells in the cerebral cortex and the hippocampus. Animals were divided into two groups, MHE and sham. Astrocytes were studied by immunostaining with glial fibrillary acidic protein and S100β protein; neurons were immunostained with neuronal nuclear marker, microtubule associated protein-2, and NF-200 and capillaries with Nestin. The hypoxia-inducible factor 1α (HIF-1α) and its downstream proteins, P-glycoprotein (P-gp) and erythropoietin receptor (Epo-R), were also evaluated. Astrocytes were increased in area and number only in the hippocampus, while S100β increased in both brain areas in MHE animals. Microtubule associated protein-2 and NF-200 immunoreactivities (-ir) were significantly reduced in both areas. Hippocampal Nestin-ir was increased in MHE animals. These cellular changes were similar to those described in ischemic conditions, thus HIF-1α, P-gp, and Epo-R were also evaluated. A high expression of HIF-1α in cortical neurons was observed in the MHE group. It is likely that this hypoxia-like state is triggered via ammonia occupying the binding domain of HIF-1α and thereby preventing its degradation and inducing its stabilization, leading to the over-expression of P-gp and the Epo-R. Rats with pre-hepatic portal hypertension because of partial portal vein ligation afford a model of minimal hepatic encephalopathy that developed hyperammonemia. The cellular changes found here were similar to those described in ischemic conditions. Besides, a high expression of HIF-1α in cortical neurons was observed. It is likely that a hypoxia-like state is triggered via ammonia occupying the binding domain of HIF-1α and thereby preventing its degradation and inducing its stabilization, leading to the over-expression of P-gp and the Epo-R.

1. The effect of paracetamol overdoses on its disposition was investigated in cholestatic rats. 2. Paracetamol plasma concentration and hepatic accumulation decrease about 70-80% in cholestatic rats. 3. Cholestatic rats intoxicated with paracetamol showed less hepatic damage as concluded from biochemical and histological findings. These data are correlated with liver and plasmatic paracetamol. 4. These results indicate a decrease in paracetamol toxicity related to stagnant bile.

Objectives: We review the current status of pathology services in low- and middle-income countries and propose an “essential pathology package” along with estimated costs. The purpose is to provide guidance to policy makers as countries move toward universal health care systems. Methods: Five key themes were reviewed using existing literature (role of leadership; education, training, and continuing professional development; technology; accreditation, management, and quality standards; and reimbursement systems). A tiered system is described, building on existing proposals. The economic analysis draws on the very limited published studies, combined with expert opinion. Results: Countries have underinvested in pathology services, with detrimental effects on health care. The equipment needs for a tier 1 laboratory in a primary health facility are modest ($2-$5,000), compared with $150,000 to $200,000 in a district hospital, and higher in a referral hospital (depending on tests undertaken). Access to a national (or regional) specialized laboratory undertaking disease surveillance and registry is important. Recurrent costs of appropriate laboratories in district and referral hospitals are around 6% of the hospital budget in midsized hospitals and likely decline in the largest hospitals. Primary health facilities rely largely on single-use tests. Conclusions: Pathology is an essential component of good universal health care.

Weanling rats fed a methyl-deficient diet develop renal necrosis with acute renal failure. The aim of this experiment was to explore further the role of coconut oil in this experimental model. Weanling Wistar male rats were fed methyl-deficient and their controls were fed methyl-supplemented diets. Coconut oil was fed at 14% and 20%, the latter concentration with and without 1% safflower oil (rich in linoleic acid); other groups received similar diets but instead of coconut oil, a mixture of hydrogenated vegetable oil and corn oil (rich in unsaturated fatty acids) was employed. Coconut oil fed at a 14% concentration did not evidence any protective outcome in relation to the renal lesions. Coconut oil at a 20% concentration showed a protective effect, mainly when the diet included safflower oil. The renal protective effect was evidenced by less or no mortality and increased survival time in the methyl-deficient rats receiving coconut oil, as well as by a reduced incidence (%) and severity of the renal lesions as evaluated by renal weight, and type (tubular and cortical necrosis or repair) and extent (grade) of the renal damage. The lack of a protective outcome when coconut oil was fed at 14%, along with the fact that in those rats receiving coconut oil at 20% the protection was greater when the diet was supplemented with 1% safflower oil, indicates that the protective effect should be attributed to the type of fatty acids coconut oil has and not to their shortage of essential fatty acids.

Background After skin cancer, breast cancer is the most common malignancy in women. Tumors of unknown origin account for 5-15% of malignant neoplasms, with 1.5% being breast cancer. An immunohistochemical panel with conventional and newer markers, such as mammaglobin, was selected for the detection of neoplastic cells of breast origin. The specific objectives are: 1) to determine the sensitivity and specificity of the panel, with a special emphasis on the inclusion of the mammaglobin marker, and 2) to compare immunohistochemistry performed on whole tissue sections and on Tissue Micro-Array. Methods Twenty-nine metastatic breast tumors were included and assumed as tumors of unknown origin. Other 48 biopsies of diverse tissues were selected and assumed as negative controls. Tissue Micro-Array was performed. Immunohistochemistry for mammaglobin, gross cystic disease fluid protein-15, estrogen receptor, progesterone receptor and cytokeratin 7 was done. Results Mammaglobin positive staining was observed in 10/29 cases, in 13/29 cases for gross cystic disease fluid protein-15, in 20/29 cases for estrogen receptor, in 9/29 cases for progesterone receptor, and in 25/29 cases for cytokeratin 7. Among the negative controls, mammaglobin was positive in 2/48, and gross cystic disease fluid protein-15 in 4/48. Conclusions The inclusion of MAG antibody in the immunohistochemical panel for the detection of tumors of unknown origin contributed to the detection of metastasis of breast cancer. The diagnostic strategy with the highest positive predictive value (88%) included hormone receptors and mammaglobin in serial manner. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1366310812718988

The association between nephrotic syndrome and juvenile idiopathic arthritis have rarely been described in pediatric patients. We report a child with steroid-responsive nephrotic syndrome, with frequent relapses, who presented with a new relapse of nephrotic syndrome associated with arthritis and uveitis at 21 months in remission after treatment with chlorambucil. Juvenile idiopathic arthritis was diagnosed and kidney biopsy examination showed mesangial glomerulonephritis with immunoglobulin M deposits. To our knowledge, only 2 cases of nephrotic syndrome preceding juvenile idiopathic arthritis have been reported, one without histopathology assessment and the other with minimal change disease. Although mesangial glomerulonephritis with nephrotic syndrome and juvenile idiopathic arthritis could have been coincidental, the immune pathogenic mechanism accepted for both diseases suggests they could be related.

In this study, we describe the presence of apoptosis, associated with a mitochondrial dysfunction in the hippocampus of animals in an experimental model defined as minimal hepatic encephalopathy (MHE). This experimental model was studied after 10 days of induced portal vein calibrated stricture, leading to portal hypertension and to a moderate hyperammonemia, without the presence of other evident central nervous system changes. The molecular mechanisms here proposed indicate the presence of apoptotic intrinsic pathways that point to hippocampal mitochondria as an important mediator of apoptosis in this experimental model. In this model of MHE, the presence of DNA fragmentation is documented by 2.3-times increased number of TUNEL-positive cells. These findings together with a higher ratio of the Bcl-2 family members Bax/Bcl-xL in the outer mitochondrial membrane of the MHE animals together with 11% of cytochrome c release indicate the presence of apoptosis in this experimental model. A detailed analysis of the hippocampal mitochondrial physiology was performed after mitochondrial isolation. The determination of the respiratory rate in the presence of malate plus glutamate and ADP showed a 45% decrease in respiratory control in MHE animals as compared with the sham group. A marked decrease of cytochrome oxidase (complex IV of the electron transport chain) was also observed, showing 46% less activity in hippocampal mitochondria from MHE animals. In addition, mitochondria from these animals showed less ability to maintain membrane potential (ΔΨm) which was 13% lower than the sham group. Light scattering experiments showed that mitochondria from MHE animals were more sensitive to swell in the presence of increased calcium concentrations as compared with the sham group. In addition, in vitro studies performed in mitochondria from sham animals showed that mitochondrial permeability transition (MPT) could be a mitochondrial mediator of the apoptotic signaling in the presence of NH4+ and calcium. Fil: Bustamante, J.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Lores Arnaiz, Silvia. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Tallis, S.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Roselló, D. M.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Lago, N.. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patologia; Argentina Fil: Lemberg, A.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina Fil: Boveris, Alberto Antonio. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Perazzo, J. C.. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina

Objectives: To elucidate the relationship of hCG administration to glycemia, Non Esterified Fatty Acids (NEFA), leptin and adiponectin levels on experimental animals previously submitted to a cafeteria diet, and then to a Low Calorie Diet (LCD). Design: Forty-one rats were selected (21 females, 20 males) and divided into seven (0-6) groups. Animals from groups 1 to 6 were fed a "cafeteria diet" with a mean energy content of 10% protein, 30% carbohydrate and 60% fat. Animals from group 0 were fed the standard laboratory diet. After the fattening period, animals from groups 1 to 6 were submitted to a restricted diet consisting of one-third the average daily intake for rats. hCG was administered for five weeks according to a specific protocol. The effects of hCG treatment were evaluated using analysis of variance (ANOVA). Results: These assessments were compared: (1) glycemia, adiponectins, leptins and non-esterified fatty acids (NEFA); (2) weight; (3) formulation effect; and (4) dose effect. Differences in leptins were observed between the Control group and Injectable A (p=0.026), Intrarectal Suspension A (p=0.20), Intrarectal Suspension B (p Conclusions: Results show the activity of hCG (both urinary and recombinant) on glycemia and leptins levels in experimental animals in different formulations.hCG administration significantly decreased blood sugar and leptin levels, whereas adiponectins were only relatively sensitive to hCG.

Background/Aims: In Argentina, hemolytic uremic syndrome (HUS) constitutes the most frequent cause of acute renal failure in children. The aim of our study was to analyze the early tubular response under the effect of Shiga toxin type 2 (Stx2) in a rat experimental model of HUS. Methods: Adult male Sprague-Dawley rats were injected intraperitoneally with culture supernatant from recombinant Escherichia coli expressing Stx2. Functional, histological, immunohistochemical and Western blot studies were performed at 48 h postinoculation. Results: Renal tubules showed the loss of the epithelial markers E-cadherin and β-catenin, and an increase in transforming growth factor-β1 expression. We detected the expression of α-smooth muscle actin in the interstitium and fibrosis in the periglomerular areas. Conclusion: Our results indicate that the early tubular response to the effects of Stx2 is related to an immunophenotype change of tubular cells and the presence of mild fibrosis in the interstitium.

Tityus trivittatus is the Argentinean scorpion reported to cause the majority of human fatalities in the country, however no systematic studies have been conducted with the venom of this species. This communication describes a general biochemical and immunological characterization of the venom obtained from T. trivittatus scorpions collected in the city of Buenos Aires and various provinces of Argentina: Catamarca, Cordoba, Entre Rios, La Rioja, Santa Fe and Santiago del Estero. These are places where human accidents were reported to occur due to this scorpion. For comparative purposes two types of samples were assayed: whole soluble venom obtained by electrical stimulation and supernatant from homogenized venomous glands. Two strains of mice (NIH and CF-1) were used for LD50 determinations by two distinct routes of administration (intravenously and intraperitoneally). Important variations were found that goes from 0.5 to 12 mg/kg mouse body weight. Samples of soluble venom were always more potent than Telson homogenates. More complex pattern was observed in homogenates compared to soluble venom, as expected. This was supported by gel electrophoretic analysis and high performance liquid chromatographic (HPLC) separations. Additionally, the HPLC profile was enriched in proteins resolved at similar elution times as other known toxins from scorpion venoms studied. Immune enzymatic assays were also conducted comparatively, using four different anti-venoms commercially available for treatment of scorpion stings (Argentinean antidote from INPB, two anti-venoms from Butantan Institute of Brazil and Alacramyn from the Mexican Bioclon Institute). Cross-reactivities were observed and are reported among the various venoms and anti-venoms used. Lung, heart, liver and pancreas pathological modifications were observed on tissues of intoxicated mice. It seems that there are important variations on the venom compositions of the various samples studied and reported here, depending on the geographical area where the scorpions were captured. The results reported here are important for the clinical outcome of human accidents. Fil: de Roodt, Adolfo Rafael. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina Fil: Coronas, Fredy I.V.. Universidad Nacional Autónoma de México. Instituto de Biotecnología; México Fil: Lago, Néstor Rubén. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Patología; Argentina Fil: González, María E.. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina Fil: Laskowicz, Rodrigo D.. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina Fil: Beltramino, Juan C.. Provincia de Santa Fe. Ministerio de Salud. Hospital de Niños “Orlando Alassia”; Argentina Fil: Saavedra, Silvina. Provincia de Entre Ríos. Ministerio de Salud. Dirección de Zoonosis; Argentina Fil: López, Raúl A.. Provincia de Catamarca. Ministerio de Salud. Departamento de Zoonosis; Argentina Fil: Reati, Gustavo J.. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Zoología Aplicada; Argentina Fil: Vucharchuk, Miriam G.. Provincia de Santiago del Estero. Ministerio de Salud. Instituto de Animales Venenosos “Jorge W. Abalos"; Argentina Fil: Bazán, Eduardo. Provincia de La Rioja. Ministerio de Salud. Dirección de Epidemiología; Argentina Fil: Varni, Liliana. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina Fil: Salomón, Oscar Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C. G. Malbrán”; Argentina Fil: Possani, Lourival D.. Universidad Nacional Autónoma de México. Instituto de Biotecnología; México

Escherichia coli strains producing Shiga toxins (Stxs) colonize the lower gastrointestinal tract and cause watery diarrhea, hemorrhagic colitis, and hemolytic-uremic syndrome (HUS). HUS is characterized by hemolytic anemia, thrombocytopenia, and acute renal failure. Oliguria associated with acute tubular necrosis and microangiopathic thrombosis has been reported as the most common cause of renal failure in Argentinean children. Our study was undertaken to obtain a model of HUS in rats that was similar to the clinical and renal histopathology findings described in humans. Rats were intraperitoneally inoculated with culture supernatant from recombinant E. coli expressing Stx2. Glomerular filtrate volume evaluated from clearance of creatinine resulted in a progressive reduction (from 53% at 24 h to 90% at 48 h). Urine volume increased significantly at 24 h but returned to normal levels at 48 h. Evidence of thrombocytopenia, anemia and leukocytosis was documented. Macroscopic analysis revealed a hyperemic peritoneal face with intestinal water accumulation. The kidneys were friable and congestive. Histopathological analysis showed glomerular and tubular necrosis as well as microangiopathic thrombosis. Our findings indicated vascular damage and kidney lesions similar to those described in humans with HUS.

To examine the cytoprotective effect of melatonin or recombinant human growth hormone (hGH) on the early phase of a running myocardial infarction in rats by using the Feulgen staining.Rats were subjected to surgical ligature of the left coronary artery or its sham-operation and were studied 1.5 3 h later. Melatonin was administered in the drinking water (100 microg/ml water) for 7 days before surgery. Recombinant hGH (2 IU/kg) was given ip at the time of surgery. Feulgen-stained histological cardiac sections were examined by light microscopy and image analysis.Infarcted rats receiving vehicle exhibited large, diffuse cardiac lesions with a marked positivity for Feulgen reaction. About 18 20% of the total area recorded became injured 1.5 or 3 h after infarction, respectively. Infarcted rats treated with melatonin or hGH, or the combination of both, and killed 3 h after surgery, showed cardiac sections with scattered lesions and only a few isolated injured muscle fibers. A similar effectiveness of melatonin and hGH, alone or in combination, to decrease injured area by 86 87% and the number of cardiac lesions by 75 80% was observed.A significant cytoprotective effect of melatonin or hGH is demonstrable in an early phase of myocardial infarction in rats.

Few cases of Kawasaki disease with acute renal failure have been described and only three articles report histological findings. We present an 8-year-old boy with typical Kawasaki disease and acute renal failure who did not require dialysis and had a complete recovery. Pathological findings in percutaneous biopsy included tubulointerstitial nephropathy with mild mesangial expansion, without vessel involvement or deposits in basal membrane. These findings were similar to those previously reported. We also detected apoptotic bodies in tubules.

Corrigendum to “Intraspecific differences in the immunochemical reactivity and neutralization of venom from Argentinean Bothrops (Rhinocerophis) alternatus by specific experimental antivenoms” [Toxicon 85 (2014) 31e45] Laura Cecilia Lanari , Alejandro Olvera , Vanessa Costa de Oliveira , Rodrigo Daniel Laskowicz , Leslie Boyer , N estor Rub en Lago , Alejandro Alag on , Adolfo Rafael de Roodt a, c, * a National Institute for Production of Biologicals, Ministry of Health, Buenos Aires, Argentina b Institute of Biotechnology, National Autonomous University of Mexico, Cuernavaca, Morelos, Mexico c Laboratory of Toxinopathology, Center of Experimental and Applied Pathology, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina d VIPER Institute, University of Arizona, Tucson, AZ, USA

We report the case of a young white man with Charcot-Marie-Tooth disease type 1 that began at 4 years. At 15 years, he developed proteinuria, arterial hypertension, and renal insufficiency. Renal biopsy specimens studied by electron microscopy showed deposition of nonamyloidotic microfibrils. This is the first report of fibrillary glomerulopathy associated with this neurological disorder. (Am J Kidney Dis 1998 Nov;32(5):E3)

Federico Ochoa1, Gisela Oltra1, Elizabeth Gerhardt1, Ricardo Hermes2, Lilian Cohen2, Alicia E Damiano3, Cristina Ibarra1, Nestor R Lago4, Elsa Zotta11Departamento de Fisiologia, Facultad de Medicina UBA, 2Laboratorio Análisis Clínicos, Hospital Juan A Fernández, 3Departamento de Ciencias Biológicas, Facultad de Farmacia y Bioquímica, UBA, Buenos Aires, Argentina; 4Departamento de Patología, Facultad de Medicina UBA, Buenos Aires, ArgentinaAbstract: In Argentina, hemolytic uremic syndrome (HUS) constitutes the most frequent cause of acute renal failure in children. Approximately 2%–4% of patients die during the acute phase, and one-third of the 96% who survive are at risk of chronic renal sequelae. Little information is available about the direct effect of Shiga toxin type 2 (Stx2) on the onset of proteinuria and the evolution of toxin-mediated glomerular or tubular injury. In this work, rats were injected intraperitoneally with recombinant Escherichia coli culture supernatant containing Stx2 (sStx2; 20 µg/kg body weight) to induce HUS. Functional, immunoblotting, and immunohistochemistry studies were carried out to determine alterations in slit diaphragm proteins and the proximal tubule endocytic system at 48 hours post-inoculation. We detected a significant increase in microalbuminuria, without changes in the proteinuria values compared to the control rats. In immunoperoxidase studies, the renal tubules and glomerular mesangium showed an increased expression of transforming growth factor ß1(TGF-ß1). The expression of megalin was decreased by immunoperoxidase and the cytoplasm showed a granular pattern of megalin expression by immunofluorescence techniques. Western blot analysis performed in the renal cortex from sStx2-treated and control rats using anti-nephrin and anti-podocalyxin antibodies showed a decreased expression of these proteins. We suggest that the alterations in slit diaphragm proteins and megalin expression could be related to the development of microalbuminuria in response to lethal doses of Stx2.Keywords: microalbuminuria, nephrin, podocytes, podocalyxin, megalin, acute renal injury