Head circumference at birth and postnatal growth trajectory in vulnerable groups from Argentina

OBJECTIVES

To investigate the association between the anthropometric status at birth and brain and bone growth during the first year of life. According to the brain-sparing hypothesis, we expect catch-up to be faster in head circumference (HC) than in body length.

METHODS

This is a longitudinal design that included Argentinian infants under 12 months of age with at least three anthropometric records. We classified study participants into four growth status categories according to z-scores for HC (HCZ) and length (LAZ) at birth, with z-score = -2 as a threshold. We used the Count model to describe growth trajectories in HC and length in the first year of life according to the growth status at birth. Recovery indicator for HC and length was taken as the time until the predicted growth trajectory surpassed the threshold curve predicted by z-score = -2 for age.

RESULTS

Growth models included 3399 infants. There were significant differences in the growth parameters between groups in all cases (p < 0.05). Within the group with a low HCZ and a low LAZ at birth, HC recovery was faster than length. In the case of a low z-score for only one of the variables, newborns with a low HCZ recovered faster than individuals born with a low LAZ.

CONCLUSIONS

The postnatal growth pattern in HC and length is associated with the growth status of HC and length at birth. As we hypothesized, the fastest postnatal recovery occurs for HC in cases of intrauterine delayed growth.

Environmental and socio-demographic individual, family and neighborhood factors associated with children intestinal parasitoses at Iguazú, in the subtropical northern border of Argentina

BACKGROUND

Intestinal parasitoses are a major concern for public health, especially in children from middle and low-income populations of tropical and subtropical areas. We examined the presence and co-infection of parasites in humans as well as parasitic environmental contamination in Puerto Iguazú, Argentina. We explored the environmental and socio-demographic characteristics of the persistence of parasites in children and their environment.

METHODOLOGY/PRINCIPAL FINDINGS

This cross-section survey was conducted among children population comprised into the area of the public health care centers of Iguazú during June 2013 to May 2016. Copro-parasitological status of 483 asymptomatic children was assessed. Simultaneously, a design-based sampling of 744 soil samples and 530 dog feces was used for characterize the environmental contamination. The 71.5% of these sites were contaminated. Sixteen genera were detected in the environment being hookworms (62.0%) the main pathogens group detected followed by Toxocara spp (16.3%), Trichuris spp (15.2%) and Giardia (6.5%). Total children prevalence raised 58.8%, detecting twelve genera of parasite with Giardia intestinalis as the most prevalent pathogen (29.0%) followed by Enterobius vermicularis (23.0%), Hymenolepis nana (12.4%) and hookworms (4.4%). Through questionnaires and census data, we characterized the socio-demographics conditions at an individual, family and neighborhood levels. A multi-level analysis including environmental contamination data showed that the ´presence of parasites´ was mostly determined by individual (e.g. age, playing habits, previous treatment) and household level (e.g. UBN, WASH, mother's literacy) determinants. Remarkably, to define the level of 'parasite co-infection', besides individual and household characteristics, environmental factors at a neighborhood level were important.

CONCLUSION/SIGNIFICANCE

Our work represents the major survey of intestinal parasites in human and environmental samples developed in the region. High prevalence was detected in the children population as well as in their environment. This work shows the importance of considering and promoting multi-level actions over the identified determinants to face this public health problem from integrative approaches.

Preclinical evaluation of anti-Helicobacter spp. activity of Hippocratea celastroides Kunth and its acute and sub-acute toxicity

Background

Hippocratea celastroides Kunth, commonly known as “cancerina”, is used in Mexican Traditional Medicine for the treatment of gastric and intestinal infections, systemic and skin inflammation, injuries and gastritis. The aim of this research was to assess the anti-Helicobacter pylori activities of hydro-ethanolic root-bark extracts from Hippocratea celastroides Kunth in naturally infected dogs, after testing their acute and subacute toxicities in mice.

Methods

To determine in vivo acute toxicity, a hydro-ethanolic extract was obtained and administered orally in female and male Balb-C mice, at doses ranging from 2000 to 5000 mg/kg. For the subacute study, a hydro-ethanolic extract was given to male and female Balb-C mice at doses ranging from 200 to 2000 mg/kg body weight. The animals were observed daily over a period of 42 days for signs of toxicity. In the pre-clinical anti-Helicobacter spp. assay, 60 dogs were included. Eighteen and 19 dogs for the experimental and control groups respectively, concluded the study. The experimental treatment consisted of H. celastroides hydro-ethanolic extract and the control treatment of amoxicillin-clarithromycin-omeprazole.

Results

Oral LD₅₀ (lethal dose 50) values for hydro-ethanolic extract were indeterminable at the highest tested doses. Under the subacute administration, neither mortality nor any sign of toxicity were observed when the hydro-ethanolic extract was administered. There were no significant alterations in biochemical parameters. The prevalence of Helicobacter spp. infection in dogs was 97.1 % for the experimental group and 100 % for the control group. Effectiveness was of 33.3 and 55 % in the experimental and control group respectively. The oral administration of H. celastroides was well-tolerated and safe.

Conclusion

The root-bark of H. celastroides produced no signs of toxicity, and manifested pharmacological activity that indicated the possibility of an alternative treatment for H. pylori infection. Effectiveness is still low so it is necessary to continue research.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1412-6) contains supplementary material, which is available to authorized users.

Detection of "Candidatus Rickettsia sp. strain Argentina"and Rickettsia bellii in Amblyomma ticks (Acari: Ixodidae) from Northern Argentina

Ixodid ticks were collected from vegetation and from humans, wild and domestic mammals in a rural area in the semi-arid Argentine Chaco in late spring 2006 to evaluate their potential role as vectors of Spotted Fever Group (SFG) rickettsiae. A total of 233 adult ticks, identified as Amblyomma parvum, Amblyomma tigrinum and Amblyomma pseudoconcolor, was examined for Rickettsia spp. We identified an SFG rickettsia of unknown pathogenicity, "Candidatus Rickettsia sp. strain Argentina", in A. parvum and A. pseudoconcolor by PCR assays targeting gltA, ompA, ompB and 17-kDa outer membrane antigen rickettsial genes. Rickettsia bellii was detected in a host-seeking male of A. tigrinum. Amblyomma parvum is widespread in the study area and is a potential threat to human health.

Flow cytometry to evaluate Anaplasma marginale parasitemia using a fluorescent nucleic acid stain

In this work we describe a flow cytometry-based method using SYTO16 (a DNA intercalating agent) to quantify Anaplasma marginale-infected erythrocytes in blood from bovine animals. The linearity and reproducibility of the results obtained with SYTO16 labeling followed by flow cytometry analysis make it a suitable approach for measurement of parasitemia in A. marginale infections.

[Role of the Shiga toxin in the hemolytic uremic syndrome]

In the last years, infection associated with Shiga toxin-producing Escherichia coli (STEC) and subsequent Hemolitic-Uremic Syndrome (HUS) became relevant as a public health since it was considered as one of the most important emergent patogen present in the food contaminated by cattle feces. STEC infection may be asymptomatic or begins with a watery diarrhea that may or may not progress to bloody diarrhea (hemorrhagic colitis) and HUS. In Argentina, HUS is the most common pediatric cause of acute renal insufficiency and the second cause of chronic renal failure. Up to now, STEC infection lacks of known effective treatment strategies that diminish risk of progression to HUS. The mechanisms by which Shiga toxin (Stx) induce HUS may help to find strategies to prevent or ameliorate HUS. In this article, recent progress that has contributed to understanding the disease pathogenesis of STEC is reviewed. New strategies to prevent further uptake of Shiga from the gut, either during the diarrheal phase or once HUS has developed are discussed.

[Cytotoxic effect of Shiga toxin type 2 and its B subunit on human renal tubular epithelial cell cultures]

Shiga toxin (Stx)-producing E. coli causing watery diarrhea, hemorrhagic colitis and hemolytic-uremic syndrome (HUS). In Argentina, HUS is the most common cause of acute renal failure in children. The purpose of the present study was to examine the cytotoxicity of Stx type 2 (Stx2) and its B subunit (Stx2B) on human renal tubular epithelial cells (HRTEC), in the presence and absence of inflammatory factors. Cytotoxic effects were assessed in terms of functionality of the epithelium, histological damage, cell viability, protein synthesis and cellular apoptosis. Results show that Stx2 regulates the passage of water through the HRTEC within an incubation period of 1h. Within longer periods, up to 72 hours, the study of morphology, viability, protein synthesis and apoptosis shows that HRTEC were sensitive to the cytotoxic action of Stx2 and Stx2B in a dose- and time-dependent manner. These effects were potentiated by lipopolysaccharides (LPS), IL-1beta, and butirate.

Ecological meltdown in predator-free forest fragments

The manner in which terrestrial ecosystems are regulated is controversial. The "top-down" school holds that predators limit herbivores and thereby prevent them from overexploiting vegetation. "Bottom-up" proponents stress the role of plant chemical defenses in limiting plant depredation by herbivores. A set of predator-free islands created by a hydroelectric impoundment in Venezuela allows a test of these competing world views. Limited area restricts the fauna of small (0.25 to 0.9 hectare) islands to predators of invertebrates (birds, lizards, anurans, and spiders), seed predators (rodents), and herbivores (howler monkeys, iguanas, and leaf-cutter ants). Predators of vertebrates are absent, and densities of rodents, howler monkeys, iguanas, and leaf-cutter ants are 10 to 100 times greater than on the nearby mainland, suggesting that predators normally limit their populations. The densities of seedlings and saplings of canopy trees are severely reduced on herbivore-affected islands, providing evidence of a trophic cascade unleashed in the absence of top-down regulation.

[Cardiac insufficiency and B-blockers]

This article summarise our experience with the Beta-Blocker in the management of congestive heart failure, which did not respond to the usual medical treatment.

[Cardiac amyloidosis secondary to multiple myeloma detected by echocardiography]

The authors present the clinical history of a 70-year-old male with arterial hypertension who sought medical advice because of dyspnea on exertion, orthopnea and episodes of paroxysmal nocturnal dyspnea. The electrocardiogram showed left arterial hemiblock and abnormalities of ventricular repolarization compatible with a left lateral endocardiac lesion. Echocardiography revealed a hypertrophied left ventricle with a small ventricular cavity, compatible with an infiltrative-restrictive myopathy. Blood chemistry showed creatinine 4.9 mg/dl, BUN 133 mg/dl and alkaline phosphatase 204 i.v. The patient expired because of intractable heart failure. The histopathological examination of a piece of myocardium (authorized by the family) stained with Congo red confirmed the presence of abundant, diffuse deposits of amyloid, as had been suspected because of the echocardiographic findings.

A tau fragment containing a repetitive sequence induces bundling of actin filaments

Much indirect evidence suggests that the interconnections of actin microfilaments with the microtubule system are mediated by microtubule-associated proteins (MAPs). In this study we provide new data to support the interaction of a specific tubulin-binding domain on tau with actin in vitro. In actin polymerization assays, the synthetic peptide VRSKIGSTENLKHQPGGG, corresponding to the first repetitive sequence of tau protein, increased turbidity at 320 nm in a dose-dependent fashion. A salient feature of the tau peptide-induced assembly process is the formation of a large amount of actin filament bundles, as revealed by electron microscopic analysis. An increase in the tau peptide concentration resulted in a proportional increase in the bundling of actin filaments. It is interesting that a gradual decrease of pH within the range 7.6-4.7 resulted in a higher effect of tau peptide in promoting bundles of actin filaments. A similar pH-dependent effect was observed for tau protein-induced bundling. An analysis of the mechanisms that operate in the peptide induction of actin filament bundles suggests the involvement of electrostatic forces, because the neutralization of epsilon-aminolysyl residues by selective carbamoylation resulted in a complete loss of the peptide induction of actin bundles. The data suggest that a tau repetitive sequence (also found in MAP-2 and MAP-4) containing a common tubulin binding motif may constitute a functional domain on tau for the dynamics of the interconnections between actin filaments and microtubules.

Cerebral sparganosis caused by Spirometra mansonoides. Case report

Cerebral sparganosis is an uncommon parasitic zoonosis caused by the migrating larva of the genus Spirometra mansonoides. The clinical and computerized tomography presentation, as well as the operative and histopathological findings, of the first known case in Mexico are detailed. The dead larva elicited intense acute inflammation resulting in focal encephalitis. Surgical removal of the larva yielded excellent results.