[Andersen-Tawil Syndrome, a differential of bidirectional ventricular tachycardia: a case report]. / Síndrome de Andersen-Tawil, un diferencial de taquicardia ventricular bidireccional: reporte de un caso.

We present the case of a patient with Andersen-Tawil syndrome (ATS), a rare genetic disorder characterized by the presence of ventricular arrhythmias, skeletal dysmorphic features, and periodic muscle paralysis. The diagnosis was delayed due to the non-simultaneity of symptom presentation. The report highlights the importance of investigating neurological symptoms in the presence of ventricular arrhythmias of unclear origin or cardiac symptoms in patients with periodic paralysis. The diagnosis was confirmed by the identification of a mutation in the KCNJ2 gene (c.224C>T(p.Thr75Met)); this specific mutation has not been reported in the gnomAD database, suggesting a minor allele frequency (MAF) of less than 1%. The patient is currently managed pharmacologically with a beta-blocker and remains free of arrhythmias.

Pulmonary Alveolar Microlithiasis in a Young Man Undergoing Lung Transplantation: A Case Report.

Pulmonary alveolar microlithiasis is a rare disease characterized by the deposition of microliths in the alveoli, attributed to mutations in the solute carrier family 34 member 2 (SLC34A2) gene. Diagnosis is often incidental to chest imaging, most frequently occurring between the second and fourth decades of life. The disease follows a progressive course and manifests with a clinical-radiological dissociation. No effective treatment is known except for lung transplantation.We report on a 28-year-old Hispanic male patient with no relevant personal or family history, presenting with progressive exertional dyspnea and intermittent dry cough. He was referred for evaluation by pulmonology due to abnormal findings on chest x-ray. High-resolution computed tomography revealed diffuse lung opacities caused by multiple microcalcifications, suggesting pulmonary alveolar microlithiasis with additional signs of pulmonary hypertension. Throughout his clinical course, he experienced a decline in functional class with severe impairment in pulmonary function tests. He underwent transplant evaluation, and the procedure was performed, with reported complications including airway stenosis, which were managed. Despite these challenges, the patient eventually showed positive progress and maintained an adequate functional class.Pulmonary alveolar microlithiasis is a rare disease with a chronic clinical course and variable manifestations. Its progressive deterioration leads to chronic respiratory failure. A high index of suspicion is required when evaluating characteristic radiological findings and conducting relevant differential diagnoses. No specific treatment guidelines are available, and lung transplantation emerges as the only effective therapy, as illustrated in the described patient.

Exceptional T CD4+ Recovery Post-antiretroviral Is Linked to a Lower HIV Reservoir with a Specific Immune Differentiation Pattern.

We present a cohort of individuals who reached CD4+ T cell counts of greater than 1,000 cells/mm3 (Hypers) after starting antiretroviral treatment (ART) and compared them with those who reached between 350 and 999 CD4+ T cells/mm3 (Concordants). Demographic data, immune recovery kinetics, T CD4+ subset phenotypes, and integrated HIV DNA were analyzed. Data from individuals living with HIV on their first ART regimen and after 48 months of follow-up were obtained. Immune phenotype by Flow Cytometry analysis on whole blood was performed, cytokines were measured, and integrated HIV-1 DNA was measured by polymerase chain reaction. From a total of 424 individuals, 26 Hypers (6.1%), 314 Concordants (74.1%), and 84 (19.8%) discordants were identified. Hypers had a higher proportion of CD4+-naive (Nv) T cells (37.6 vs. 24.8, p < .05), and a low proportion of CD4+ effector memory T cells (27.9 vs. 39.4, p < .05), with similar results found in CD8+ T cells. Hypers demonstrated a higher percentage of CD4+CD45RA+CD31neg cells with a lower response to interleukin-2 stimulation and a lower integrated HIV-1 DNA/CD4 ratio (1.2 vs. 2.89, p < .05). In Hypers, T cell recovery occurs very early after initiation of ART. Following this initial recovery state, their CD4+ T cell level homeostasis seems to be driven by nonthymic-central-Nv cells. This exceptional recovery is associated with a lower HIV reservoir, which may be related to an increase in noninfected CD4+ T cells. These patients could then be eligible candidates for cure trials.

Tailoring the structure of MoS2 using ball-milled MoO3 powders: hexagonal, triangular, and fullerene-like shapes.

Single and few-layered MoS2 materials have attracted attention due to their outstanding physicochemical properties with potential applications in optoelectronics, catalysis, and energy storage. In the past, these materials have been produced using the chemical vapor deposition (CVD) method using MoO3 films and powders as Mo precursors. In this work, we demonstrate that the size and morphology of few-layered MoS2 nanostructures can be controlled, modifying the Mo precursor mechanically. We synthesized few-layered MoS2 materials using MoO3 powders previously exposed to a high-energy ball milling treatment by the salt-assisted CVD method. The MoO3 powders milled for 30, 120, and 300 min were used to synthesize sample MoS2-30, MoS2-120, and MoS2-300, respectively. We found morphologies mainly of hexagons (MoS2-30), triangles (MoS2-120), and fullerenes (MoS2-300). The MoS2 nanostructures and MoO3 powders were characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, x-ray diffraction, and thermogravimetric analysis. It was found that MoO3 milled powders exhibit oxygen loss and decrease in crystallite size as milling time increases. Oxygen deficiency in the Mo precursor prevents the growth of large MoS2 crystals and a large number of milled MoO3-x  + NaCl promote greater nucleation sites for the formation of MoS2, achieving a high density of nanoflakes in the 2H and 3R phases, with diameter sizes in the range of ∼30-600 nm with 1-12 layers. Photoluminescence characterization at room temperature revealed a direct bandgap and exciting trends for the different MoS2 samples. We envisage that our work provides a route for modifying the structure and optical properties for future device design via precursor engineering.

Persistent high levels of immune activation and their correlation with the HIV-1 proviral DNA and 2-LTR circles loads, in a cohort of Mexican individuals following long-term and fully suppressive treatment.

OBJECTIVES: The aim of this study was to investigate the correlation between the HIV-1 reservoir and the levels of immune activation in chronic patients under fully suppressive cART. METHODS: We quantified the HIV proviral DNA and 2-LTR circles loads from PBMCs, the levels of CD38+ and Ki-67+ T-cells, and the levels of IL-7 in a cohort of patients with more than 5 years of ART at enrollment and after 1 year. RESULTS: In 29 participants with a median of 8 years (IQR, 6.9-9.4) under suppressive cART we found higher levels of CD8+ CD38+ T-cells after 1-year (P = .000). There was a non-statistically significant poor correlation between the levels of immune activation and the proviral DNA of CD4+ and CD8+ T-cells. Ki-67+ T-cells declined without significant differences, and there was no significant correlation with the proportion of CD38+. IL-7 decreased at the follow-up observation (P = .094), but there was no correlation with the levels of CD38+ and Ki-67+ T-cells. CONCLUSIONS: We found a weak but non-statistically significant correlation of the levels of T-cell activation with the proviral DNA and 2-LTR circles. This suggests the likely occurrence of further mechanisms driving chronic versus early immune activation other than viral replication by itself in chronic patients.

HIV-1 acquired drug resistance to integrase inhibitors in a cohort of antiretroviral therapy multi-experienced Mexican patients failing to raltegravir: a cross-sectional study.

BACKGROUND: In resource-limited settings, multi-experienced HIV infected patients are often prescribed raltegravir for salvage therapy. Patients failing raltegravir-containing regimens require other drugs including other integrase inhibitors. In this context, real-life data about the resistance and cross-resistance pathways between integrase inhibitors is limited. The aim of this study was to investigate integrase resistance pathways in a cohort of Mexican multi-experienced patients failing of a raltegravir-containing salvage regimen. METHODS: Twenty-five plasma samples from subjects failing antiretroviral regimens which included raltegravir were obtained from various healthcare centres from 2009 to 2017 in Mexico. Antiretroviral history and demographics were collected. Samples were processed for integrase resistance genotyping testing by sequencing. The viral sequences were analysed with the Stanford HIV drug resistance database algorithm. Data was analysed with SPSS Statistics software. RESULTS: We found a mean viral load of 4.17 log10 c/mL (SD 1.11) at the time of virologic failure. Forty-eight percent of the samples were raltegravir resistant. The Y143R/H/C substitutions were the most prevalent, followed by the N155H, and both Q148H/K and G140S/A in the same proportion. The Q148 + G140 combination was found in (12%) of the samples. Cross-resistance to elvitegravir was found in 83.3% and in 18.2% for both dolutegravir and bictegravir. Thirteen samples (52%) were susceptible to the four integrase strand-transfer inhibitors. CONCLUSIONS: Our findings suggest a high occurrence of resistance and cross-resistance to other integrase inhibitors among multi-experienced subjects failing raltegravir. We found a modestly lower proportion of cross-resistance to dolutegravir than data from clinical trials. Likely this drug could be used for salvage therapy. Explanations for the absence of mutations in half of the samples, other than reduced adherence, should be further investigated. Close surveillance is needed.

Understanding the electrochemistry of armchair graphene nanoribbons containing nitrogen and oxygen functional groups: DFT calculations.

The surface and edge chemistry are vital points to assess a specific application of graphene and other carbon nanomaterials. Based on first-principles density functional theory, we investigate twenty-four chemical functional groups containing oxygen and nitrogen atoms anchored to the edges of armchair graphene nanoribbons (AGNRs). Results for the band structures, formation energy, band gaps, electronic charge deficit, oxidation energy, reduction energy, and global hydrophilicity index are analyzed. Among the oxygen functional groups, carbonyl, anhydride, quinone, lactone, phenol, ethyl-ester, carboxyl, α-ester-methyl, and methoxy act as electron-withdrawing groups and, conversely, pyrane, pyrone, and ethoxy act as electron-donating groups. In the case of nitrogen-functional groups, amine, N-p-toluidine, ethylamine, pyridine-N-oxide, pyridone, lactam, and pyridinium transfer electrons to the AGNRs. Nitro, amide, and N-ethylamine act as electron-withdrawing groups. The carbonyl and pyridinium group-AGNRs show metallic behavior. The formation energy calculations revealed that AGNRs with pyridinium, amine, pyrane, carbonyl, and phenol are the most stable structures. In terms of the global hydrophilicity index, the quinone and N-ethylamine groups showed the most significant values, suggesting that they are highly efficient in accepting electrons from other chemical species. The oxidation and reduction energies as a function of the ribbon's width are discussed for AGNRs with quinone, hydroquinone, nitro, and nitro + 2H. Besides, we discuss the effect of nitrogen-doping in AGNRs on the oxidation and reduction energies for the quinone and hydroquinone functional groups.

Oral infection of mice and host cell invasion by Trypanosoma cruzi strains from Mexico.

Oral infection by Trypanosoma cruzi has been responsible for frequent outbreaks of acute Chagas disease in the north of South America and in the Amazon region, where T. cruzi genetic group TcI predominates. TcI strains from different geographical regions have been used in oral infection in mice, but there is no information about strains from Mexico where TcI is prevalent. Here, we analyzed four Mexican strains as concerns the course of oral infection, the ability to invade host cells in vitro, and the profile of metacyclic trypomastigote surface molecules gp82 and gp90 that are implicated in parasite internalization. Oral infection of mice with metacyclic forms of all strains resulted in reduced blood and tissue parasitism, and mild to moderate inflammatory process in the heart/skeletal muscle. They expressed pepsin-resistant gp82 and gp90 molecules at high levels and invaded host cells poorly in full nutrient medium and efficiently under nutrient-deprived condition. The properties exhibited by Mexican strains were similar to those displayed by TcI strains from other geographical regions, reinforcing the notion that these features are common to the genetic group TcI as a whole.

Leishmania infection in bats from a non-endemic region of Leishmaniasis in Brazil.

Leishmaniasis is a complex of zoonotic diseases caused by parasites of the genus Leishmania, which can develop in domestic as well as wild animals and humans throughout the world. Currently, this disease is spreading in rural and urban areas of non-endemic regions in Brazil. Recently, bats have gained epidemiological significance in leishmaniasis due to its close relationship with human settlements. In this study, we investigated the presence of Leishmania spp. DNA in blood samples from 448 bats belonging to four families representing 20 species that were captured in the Triangulo Mineiro and Alto Paranaiba areas of Minas Gerais State (non-endemic areas for leishmaniasis), Brazil. Leishmania spp. DNA was detected in 8·0% of the blood samples, 41·6% of which were Leishmania infantum, 38·9% Leishmania amazonensis and 19·4% Leishmania braziliensis. No positive correlation was found between Leishmania spp. and bat food source. The species with more infection rates were the insectivorous bats Eumops perotis; 22·2% (4/18) of which tested positive for Leishmania DNA. The presence of Leishmania in the bat blood samples, as observed in this study, represents epidemiological importance due to the absence of Leishmaniasis cases in the region.

The decrease in the population of Gluconacetobacter diazotrophicus in sugarcane after nitrogen fertilization is related to plant physiology in split root experiments.

It has been established that a decrease in the population of Gluconacetobacter diazotrophicus associated with sugarcane occurs after nitrogen fertilization. This fact could be due to a direct influence of NH(4)NO(3) on bacterial cells or to changes in plant physiology after fertilizer addition, affecting bacterial establishment. In this work, we observed that survival of G. diazotrophicus was directly influenced when 44.8mM of NH(4)NO(3) (640mgN/plant) was used for in vitro experiments. Furthermore, micropropagated sugarcane plantlets were inoculated with G. diazotrophicus and used for split root experiments, in which both ends of the system were fertilized with a basal level of NH(4)NO(3) (0.35mM; 10mgN/plant). Twenty days post inoculation (dpi) one half of the plants were fertilized with a high dose of NH(4)NO(3) (6.3mM; 180 mgN/plant) on one end of the system. This nitrogen level was lower than that directly affecting G. diazotrophicus cells; however, it caused a decrease in the bacterial population in comparison with control plants fertilized with basal nitrogen levels. The decrease in the population of G. diazotrophicus was higher in pots fertilized with a basal nitrogen level when compared with the corresponding end supplied with high levels of NH4NO3 (100dpi; 80 days post fertilization) of the same plant system. These observations suggest that the high nitrogen level added to the plants induce systemic physiological changes that affect the establishment of G. diazotrophicus.

La disminución de la población de Gluconacetobacter diazotrophicus en caña de azúcar, después de la fertilización nitrogenada, está relacionada con la fisiología de las plantas en experimentos de raíz dividida / The decrease in the population of Gluconacetobacter diazotrophicus in sugarcane after nitrogen fertilization is related to plant physiology in split root experiments

It has been established that a decrease in the population of Gluconacetobacter diazotrophicus associated with sugarcane occurs after nitrogen fertilization. This fact could be due to a direct influence of NH4NO3 on bacterial cells or to changes in plant physiology after fertilizer addition, affecting bacterial establishment. In this work, we observed that survival of G. diazotrophicus was directly influenced when 44.8 mM of NH4NO3 (640 mg N/plant) was used for in vitro experiments. Furthermore, micropropagated sugarcane plantlets were inoculated with G. diazotrophicus and used for split root experiments, in which both ends of the system were fertilized with a basal level of NH4NO3 (0.35 mM; 10 mg N/plant). Twenty days post inoculation (dpi) one half of the plants were fertilized with a high dose of NH4NO3 (6.3 mM; 180 mg N/plant) on one end of the system. This nitrogen level was lower than that directly affecting G. diazotrophicus cells; however, it caused a decrease in the bacterial population in comparison with control plants fertilized with basal nitrogen levels. The decrease in the population of G. diazotrophicus was higher in pots fertilized with a basal nitrogen level when compared with the corresponding end supplied with high levels of NH4NO3 (100 dpi; 80 days post fertilization) of the same plant system. These observations suggest that the high nitrogen level added to the plants induce systemic physiological changes that affect the establishment of G. diazotrophicus.

La población de Gluconacetobacter diazotrophicus asociada a la caña de azúcar disminuye después de la fertilización nitrogenada, lo cual podría ocurrir por la influencia directa del NH4NO3 sobre la supervivencia bacteriana, o por cambios en la fisiología de las plantas, que impiden el establecimiento bacteriano. En el presente trabajo se observó que en experimentos in vitro la supervivencia de G. diazotrophicus fue influenciada por 44,8 mM de NH4NO3 (640 mg N/plant). Además, G. diazotrophicus fue inoculado en plántulas micropropagadas de caña de azúcar, que fueron usadas para realizar experimentos de raíz dividida, en las que ambos extremos de los sistemas se fertilizaron con un nivel basal de NH4NO3 (0,35 mM; 10 mg N/planta). A los 20 días posteriores a la inoculación (dpi), la mitad de plantas fueron fertilizadas en uno de sus extremos con una dosis elevada de NH4NO3 (6,3 mM; 180 mg of N/plant). Este nivel fue menor al que afectó directamente a las células de G. diazotrophicus; sin embargo, provocó una disminución de la población bacteriana en comparación con plantas testigo fertilizadas con niveles basales de nitrógeno. La disminución de la población fue mayor para raíces fertilizadas con un nivel basal de nitrógeno en comparación con las raíces fertilizadas con altos niveles del mismo sistema de plantas (100 dpi; 80 días posfertilización). Estas observaciones indican que el alto nivel de nitrógeno añadido a las plantas inducen cambios fisiológicos sistémicos que afectan el establecimiento de G. diazotrophicus.

Arteria trigeminal persistente: reporte de tres casos / Persistent trigeminal artery: three case reports

La persistencia de la arteria trigeminal es una alteración vascular infrecuente y representa la permanencia, después del nacimiento, de la comunicación entre el sistema carotideo y el sistema vertebro-basilar. Esta persistencia se ha asociado a la existencia de otras alteraciones de la morfología vascular cerebral y a condiciones clínicas variadas. Reportamos tres casos de persistencia de la arteria trigeminal, dos como hallazgo incidental en pacientes con sintomatología transitoria y uno en un cuadro de hemorragia subaracnoidea, identificados mediante reconstrucción tridimensional de imágenes obtenidas por angiotomografía.

Persistent trigeminal artery is a rare vascular disorder and represents the permanence of the communication between the carotid system and vertebrobasilar system after birth. This persistence has been associated with the existence of other alterations of brain vascular morphology and different clinical conditions. We report three cases of persistent trigeminal artery, two incidental findings in patients with transient symptoms and one in a patient with subarachnoid hemorrhage, identified by three-dimensional reconstruction of images obtained by angiotomography.

The successful application of a national peer advisory committee for physicians who provide salvage regimens to heavily antiretroviral-experienced patients in mexican human immunodeficiency virus clinics.

BACKGROUND: Designing optimal antiretroviral (ARV) salvage regimens for multiclass drug-resistant, human immunodeficiency virus (HIV)-infected patients demands specific clinical skills. Our aim was to assess the virologic and immunologic effects of the treatment recommendations drafted by a peer advisory board to physicians caring for heavily ARV-experienced patients. METHODS: We conducted a nationwide, HIV clinic-based, cohort study in Mexico. Adults infected with HIV were assessed for a median of 33 months (interquartile range [IQR] = 22-43 months). These patients had experienced the virologic failure of at least 2 prior ARV regimens and had detectable viremia while currently being treated; their physicians had received therapeutic advice, by a panel of experts, regarding the ARV salvage regimen. The primary endpoint was the incidence of loss of virologic response (plasma HIV-RNA levels of <200 copies per mL, followed by levels above this threshold) during the follow-up assessment using an observed-failure competing risks regression analysis. RESULTS: A total of 611 patients were observed (median ARV therapy exposure = 10.5 years; median prior regimens = 4). The probabilities of virologic failure were 11.9%, 14.4%, 16.9%, and 19.4% at the 12-, 24-, 36-, and 48-month follow-up assessments, respectively. Of the 531 patients who achieved a confirmed plasma HIV-RNA level below 200 copies per mL, the median increase in blood CD4(+) T-cell count was 162 cells per mL (IQR = 45-304 cells per mL). CONCLUSIONS: In routine practice, a high rate of patients with extensive ARV experience, who received an optimized salvage regimen recommended by a peer advisory committee, achieved a long-term sustained virologic response and immune reconstitution.

Gene identification and comparative molecular modeling of a Trypanosoma rangeli major surface protease.

Trypanosoma rangeli is a hemoflagellate parasite which is able to infect humans. Distinct from Trypanosoma cruzi, the causative agent of Chagas disease, T. rangeli is non-pathogenic to the vertebrate host. The manner by which the T. rangeli interacts with the host is still unknown, but it certainly depends on the surface molecules. Major surface proteins (MSP) are GPI-anchored, zinc-dependent metalloproteases present in the surface of all trypanosomatids studied so far, which are implicated as virulence factors in pathogenic trypanosomatids, such as Leishmania spp and T. cruzi. The aims of this work were to generate the complete sequence of a T. rangeli MSP (TrMSP) gene and to determine the 3D-structure of the predicted protein by homology modeling. The plasmid bearing a complete copy of a TrMSP gene was completely sequenced and the predicted protein was modeled using Modeller software. Results indicate that TrMSP open reading frame (ORF) codes for a predicted 588 amino acid protein and shows all elements required for its posttranslational processing. Multiple sequence alignment of TrMSP with other trypanosomatids' MSPs showed an extensive conservation of the N-terminal and central regions and a more divergent C-terminal region. Leishmania major MSP (LmMSP), which had its crystal structure previously determined, has an overall 35% identity with TrMSP. This identity allowed the comparative molecular modeling of TrMSP, which demonstrated a high degree of structural conservation between MSPs from other trypanosomatids (TrypMSPs). All modeled MSPs have a conserved folding pattern, apart from structural divergences in the C-domain and discrete differences of charge and topology in the catalytic cleft, and present the same geometry of the canonical HEXXH zinc-binding motif. The determination of surface charges of the molecules revealed that TrMSP is a predominantly positive protein, whereas LmMSP and Trypanosoma cruzi MSP (TcMSP) are negative proteins, suggesting that substrates recognized by TcMSP and LmMSP could not interact with TrMSP. Moreover, the comparison between TrMSP and TcMSP protein sequences has revealed 45 non-neutral amino acid substitutions, which can be further assessed through protein engineering. The characteristics of TrMSP could explain, at least in part, the lack of pathogenicity of T. rangeli to humans and point to the necessity of identifying the biological targets of this enzyme.

Transmitted HIV drug resistance among drug-naive subjects recently infected with HIV in Mexico City: a World Health Organization survey to classify resistance and to field test two alternative patient enrollment methods.

In 2004, the World Health Organization performed a survey to assess transmitted drug resistance in Mexico City among drug-naive persons with newly diagnosed human immunodeficiency virus (HIV) infection and likely to be recently infected who were attending 3 voluntary counseling and testing sites. A parallel study comparing 2 alternative methods of enrolling survey participant was conducted in 9 voluntary counseling and testing sites in central Mexico. In study arm 1, subject information, consent and blood specimens were obtained during the HIV diagnostic testing visit. In study arm 2, consent and blood specimens were obtained at the return visit, only from those who were HIV infected. This survey classified nonnucleoside reverse-transcriptase inhibitor and nucleoside reverse-transcriptase inhibitor transmitted drug resistance as <5% and 5%-15%, respectively. Arm 2 yielded major advantages in cost and workload, with no evidence of increased sampling bias.

Effects of progesterone on the content of CCR5 and CXCR4 coreceptors in PBMCs of seropositive and exposed but uninfected Mexican women to HIV-1.

CCR5 and CXCR4 play an important role in the establishment of HIV infection and disease progression. Caucasian people exposed to HIV but uninfected (EU) present a deletion of 32bp in CCR5 that has not been reported in EU Hispanics from Latin America. Therefore, other factors besides mutations should be involved in this phenomenon. Studies in healthy women have shown that sex hormones such as progesterone (P) can modulate CCR5/CXCR4 expression through an unknown mechanism. The aim of this paper was to determine the role of P in the regulation of CCR5 and CXCR4 in peripheral blood mononuclear cells (PBMCs) of HIV-1 infected and EU women. We analyzed HIV-1-infected women with stable highly active antiretroviral therapy (HAART) with CD4+ cell counts <400/mm(3) or diminution of 20%, EU and HIV-1 seronegative healthy controls. 5×10(6) PBMCs, from HIV-1 infected women, EU women and HIV-1 seronegative healthy controls were cultured and incubated with P (10 or 100 nM), RU486 (P antagonist, 1 µM) or P (100 nM)+RU486 (1 µM). CCR5/CXCR4 content was determined by Western blot. Densitometry data were analyzed using Mann-Whitney test. We found that CCR5 content was reduced by P in all groups. In contrast, CXCR4 content was increased by P in healthy controls and in HIV-1 infected women. Interestingly, CXCR4 content was reduced by P in EU. RU486 did not block P effects in any group. These findings suggest that P should participate in the acquisition and progression of HIV-1 infection by modulating CCR5 and CXCR4 expression. P could contribute to the resistance acquisition of HIV by EU through the down-regulation of both coreceptors.

Growth response of maize plantlets inoculated with Enterobacter spp., as a model for alternative agriculture / Respuesta de plántulas de maíz inoculadas con Enterobacter spp. como un modelo de agricultura alternativa

A maize rhizosphere isolate was phenotypically and genotypically characterized and identifed as Enterobacter spp. bacterium. Germinated seeds were inoculated, the plantlets were sown in vermiculite and in soil and grown under laboratory and feld conditions, respectively. The adherence, colonization and plant growth promotion capability of Enterobacter sp. UAPS03001 was evaluated in "Rojo-Criollo" maize under laboratory conditions. Twenty days after inoculation, the treated plantlets showed larger biomass than non-inoculated ones. In feld grown plants, the kernel biomass was also greater in inoculated than in non-inoculated plants. The inoculation of maize sprouts with plant growth- promoting bacteria before their sowing in the feld would be an alternative practice for achieving successful yield in temporal agriculture.

En este trabajo se aisló una bacteria de la rizósfera de maíz, que fue caracterizada mediante métodos fenotípicos y genotípicos e identifcada como Enterobacter sp. UAPS03001. La bacteria fue inoculada en semillas de maíz "Rojo-Criollo" germinadas en forma axénica. Las semillas germinadas e inoculadas se plantaron en vermiculita y posteriormente las plántulas fueron cultivadas en vermiculita o en suelo, para evaluar el efecto promotor del crecimiento vegetal de dicha bacteria, bajo condiciones de laboratorio y de campo. Bajo condiciones de laboratorio, también se evaluó la capacidad de esta cepa para adherirse a las plantas de maíz y colonizarlas. Veinte días después de la inoculación, las plántulas inoculadas mostraron una biomasa mayor con referencia a las no inoculadas. En campo, la biomasa de la mazorca fue también mayor en las plantas inoculadas respecto de las plantas no inoculadas. La inoculación de germinados de maíz con una bacteria promotora del crecimiento vegetal y su posterior transferencia a campo podría ser una práctica alternativa para llevar a cabo una producción exitosa en agricultura de temporal.

Growth response of maize plantlets inoculated with Enterobacter spp., as a model for alternative agriculture.

A maize rhizosphere isolate was phenotypically and genotypically characterized and identified as Enterobacter spp. bacterium. Germinated seeds were inoculated, the plantlets were sown in vermiculite and in soil and grown under laboratory and field conditions, respectively. The adherence, colonization and plant growth promotion capability of Enterobacter sp. UAPS03001 was evaluated in "Rojo-Criollo" maize under laboratory conditions. Twenty days after inoculation, the treated plantlets showed larger biomass than non-inoculated ones. In field grown plants, the kernel biomass was also greater in inoculated than in non-inoculated plants. The inoculation of maize sprouts with plant growth- promoting bacteria before their sowing in the field would be an alternative practice for achieving successful yield in temporal agriculture.

Genome survey sequence analysis and identification of homologs of major surface protease (gp63) genes in Trypanosoma rangeli.

In this study, 222 genome survey sequences were generated for Trypanosoma rangeli strain P07 isolated from an opossum (Didelphis albiventris) in Minas Gerais State, Brazil. T. rangeli sequences were compared by BLASTX (Basic Local Alignment Search Tool X) analysis with the assembled contigs of Leishmania braziliensis, Leishmania infantum, Leishmania major, Trypanosoma brucei, and Trypanosoma cruzi. Results revealed that 82% (182/222) of the sequences were associated with predicted proteins described, whereas 18% (40/222) of the sequences did not show significant identity with sequences deposited in databases, suggesting that they may represent T. rangeli-specific sequences. Among the 182 predicted sequences, 179 (80.6%) had the highest similarity with T. cruzi, 2 (0.9%) with T. brucei, and 1 (0.5%) with L. braziliensis. Computer analysis permitted the identification of members of various gene families described for trypanosomatids in the genome of T. rangeli, such as trans-sialidases, mucin-associated surface proteins, and major surface proteases (MSP or gp63). This is the first report identifying sequences of the MSP family in T. rangeli. Multiple sequence alignments showed that the predicted MSP of T. rangeli presented the typical characteristics of metalloproteases, such as the presence of the HEXXH motif, which corresponds to a region previously associated with the catalytic site of the enzyme, and various cysteine and proline residues, which are conserved among MSPs of different trypanosomatid species. Reverse transcriptase-polymerase chain reaction analysis revealed the presence of MSP transcripts in epimastigote forms of T. rangeli.

HIV Drug Resistance-Associated Mutations in Antiretroviral Naïve HIV-1-Infected Latin American Children.

Our goal was to describe the presence of HIV drug resistance among HIV-1-infected, antiretroviral (ARV) naïve children and adolescents in Latin America and to examine resistance in these children in relation to drug exposure in the mother. Genotyping was performed on plasma samples obtained at baseline from HIV-1-infected participants in a prospective cohort study in Brazil, Argentina, and Mexico (NISDI Pediatric Study). Of 713 HIV-infected children enrolled, 69 were ARV naïve and eligible for the analysis. At enrollment, mean age was 7.3 years; 81.2% were infected with HIV perinatally. Drug resistance mutations (DRMs) were detected in 6 (8.7%; 95% confidence interval 3.1-18.2%) ARV-naïve subjects; none of the mothers of these 6 received ARVs during their pregnancies and none of the children received ARV prophylaxis. Reverse transcriptase mutations K70R and K70E were detected in 3 and 2 subjects, respectively; protease mutation I50 V was detected in 1 subject. Three of the 6 children with DRMs initiated ARV therapy during followup, with a good response in 2. The overall rate of primary drug resistance in this pediatric HIV-infected population was low, and no subjects had more than 1 DRM. Mutations associated with resistance to nucleoside reverse transcriptase inhibitors were the most prevalent.