Bacteria isolated from explosive contaminated environments transform pentaerythritol tetranitrate (PETN) under aerobic and anaerobic conditions.

Pentaerythritol tetranitrate (PETN) is a nitrate ester explosive that may be persistent with scarce reports on its environmental fate and impacts. Our main objective was to isolate and characterize bacteria that transform PETN under aerobic and anaerobic conditions. Biotransformation of PETN (100 mg L-1) was evaluated using mineral medium with (M + C) and without (M - C) additional carbon sources under aerobic conditions and with additional carbon sources under anaerobic conditions. Here, we report on the isolation of 12 PETN-transforming cultures (4 pure and 8 co-cultures) from environmental samples collected at an explosive manufacturing plant. The highest transformation of PETN was observed for cultures in M + C under aerobic conditions, reaching up to 91% ± 2% in 2 d. Under this condition, PETN biotransformation was observed in conjunction with the release of nitrites and bacterial growth. No substantial transformation of PETN (<45%) was observed during 21 d in M - C under aerobic conditions. Under anaerobic conditions, five cultures could transform PETN (up to 52% ± 13%) as the sole nitrogen source, concurrent with the formation of two unidentified metabolites. PETN-transforming cultures belonged to Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, and Actinobacteria. In conclusion, we isolated 12 PETN-transforming cultures belonging to diverse taxa, suggesting that PETN transformation is phylogenetically widespread.

Diagnostic performance of the culture and susceptibility of Helicobacter pylori in peruvian patients: results from a sentinel laboratory. / Rendimiento diagnóstico del cultivo y susceptibilidad de Helicobacter pylori en pacientes peruanos: resultados de un laboratorio centinela.

OBJECTIVE: To analyze the antimicrobial susceptibility of Helicobacter pylori to 5 reference antibiotics, in a population of 500 dyspeptic patients from the Gastroenterology Service of the Cayetano Heredia Hospital (n = 419) and the Cayetano Heredia Clinic (n = 81) in Lima, Peru. MATERIALS AND METHODS: Gastric biopsies were collected from 500 patients diagnosed with dyspepsia. From these biopsies, 273 H. pylori strains were isolated and cultured to confirm H. pylori infection by histological and culture diagnosis. Finally, antimicrobial susceptibility was analyzed using the broth microdilution method, and the resistance profiles of each antimicrobial and multi-resistance patterns were evaluated by statistical analysis. RESULTS: The diagnosis of H. pylori infection by culture, compared to histological testing, reported a sensitivity of 83.8%, a specificity of 89.9% and an area under the curve (AUC) of 0.87 (95% CI: 0.84 to 0.90). The frequency of infection in the gastroenterology services of the Cayetano Heredia Hospital and Clinic was 56.6% (237/419) and 44.4% (36/81), respectively. An increase in antimicrobial resistance to Amoxicillin (45.1% / 29.6%), Levofloxacin (71.8%/ 74.1%) and Metronidazole (69.8% / 63.0%) was found in the Hospital and the Clinic, respectively. Multiple resistance patterns showed that the most frequent resistance (double and triple) was to Levofloxacin, Metronidazole and Amoxicillin. CONCLUSIONS: The antimicrobial resistance of H. pylori has increased compared to that reported in previous years. Furthermore, H. pylori multiple resistance presents high frequencies in infected patients. The broth microdilution method could be implemented in different hospitals in Peru as a surveillance tool for H. pylori antimicrobial resistance.

OBJETIVO: Analizar la susceptibilidad antimicrobiana de Helicobacter pylori a 5 antibióticos de referencia, en pacientes dispépticos del Servicio de Gastroenterología del Hospital Cayetano Heredia y la Clínica Cayetano Heredia en Lima, Perú. MATERIALES Y MÉTODOS: Se colectaron biopsias gástricas de 500 pacientes diagnosticados con dispepsia. A partir de estas biopsias, se aislaron y cultivaron 273 cepas de H. pylori para confirmar la infección mediante el diagnóstico histológico y por cultivo. Finalmente, se analizó la susceptibilidad antimicrobiana mediante el método de microdilución en caldo y se evaluaron los perfiles de resistencia de cada antimicrobiano y los patrones de multirresistencia. RESULTADOS: El diagnóstico de H. pylori por cultivo, comparado con la prueba histológica, reportó una sensibilidad del 83,8%, una especificidad del 89,9% y un área bajo la curva de 0,87 (IC95%: 0,84 a 0,90). La frecuencia de la infección en los servicios de gastroenterología del Hospital y la Clínica Cayetano Heredia fueron del 56,6% (237/419) y 44,4% (36/81), respectivamente. Según el Hospital/Clínica, se determinó la resistencia para amoxicilina (45,1%/29,6%), levofloxacino (71,8%/74,1%) y metronidazol (69,8%/63,0%). Los patrones de resistencia a múltiples antimicrobianos demostraron que las resistencias (dobles y triples) más frecuentes fueron con levofloxacino, metronidazol y amoxicilina. CONCLUSIONES: La resistencia antimicrobiana de H. pylori ha aumentado con respecto a los años previos. Además, la resistencia múltiple de H. pylori presenta altas frecuencias en pacientes infectados. El método de microdilución en caldo podría ser implementado en los diferentes hospitales del Perú como una herramienta de vigilancia de la resistencia de H. pylori a los antimicrobianos.

Toxicity assessment of synthetic chalcones with antileishmanial potential in BALB/c mice. / Evaluación de la toxicidad de chalconas sintéticas con potencial anti-Leishmania en ratones BALB/c.

OBJECTIVE: To evaluate the toxicity of three synthetic chalcones administered intraperitoneally to BALB/c mice. MATERIALS AND METHODS: The median lethal dose (LD50) was estimated by Dixon's Up-and-Down method. Subchronic toxicity of chalcones was evaluated at 20 and 40 mg/kg for 21 days. Behavioral, physiological, biochemical, and histological toxic effects were evaluated. RESULTS: Chalcone 43 produced mucus in feces, visceral damage (liver) and alterations in organ coefficient (kidney, p = 0.037 and brain, p = 0.008) when compared to the control group. In addition, histological analysis showed that this chalcone produced edema, inflammation and necrosis in the evaluated organs, although there was no significant difference with the control. None of the biochemical parameters differed significantly between the treatment groups at 40 mg/kg dose and the control. CONCLUSIONS: The LD50 for all three chalcones was greater than 550 mg/kg of body weight. Chalcones 40 and 42 were found to be relatively non-toxic. Both can be considered safe for intraperitoneal application in BALB/c mice and, consequently, are potential candidates for use in the treatment of leishmaniasis.

OBJETIVO: Evaluar la toxicidad de tres chalconas sintéticas administradas por vía intraperitoneal en ratones BALB/c. MATERIALES Y MÉTODOS: La dosis letal media (DL50) se estimó por el método Up-and-Down de Dixon. La toxicidad subcrónica de las chalconas se evaluó a 20 y 40   mg/kg por 21 días. Se evaluó el efecto tóxico a nivel de comportamiento, fisiológico, bioquímico e histológico. RESULTADOS: La chalcona 43 generó moco en las heces, daño visceral (hígado) y alteración en el coeficiente de órganos (riñón, p   =   0,037 y cerebro, p   =   0,008) en comparación con el grupo control. Además, en el análisis histológico se observó que esta chalcona produjo edema, inflamación y necrosis en los órganos evaluados, aunque no hubo diferencia significativa con el control. Todos los parámetros bioquímicos no difirieron significativamente entre los grupos de tratamiento a dosis de 40   mg/kg y el control. CONCLUSIONES: La DL50 para las tres chalconas fue superior a 550   mg/kg de peso corporal. Las chalconas 40 y 42 son relativamente no tóxicas. Ambas pueden considerarse seguras para la aplicación vía intraperitoneal en ratones BALB/c y, en consecuencia, son posibles candidatas para ser usadas en el tratamiento contra las leishmaniosis.

Rendimiento diagnóstico del cultivo y susceptibilidad de Helicobacter pylori en pacientes peruanos: resultados de un laboratorio centinela / Diagnostic performance of the culture and susceptibility of Helicobacter pylori in peruvian patients: results from a sentinel laboratory

RESUMEN Objetivo: Analizar la susceptibilidad antimicrobiana de Helicobacter pylori a 5 antibióticos de referencia, en pacientes dispépticos del Servicio de Gastroenterología del Hospital Cayetano Heredia y la Clínica Cayetano Heredia en Lima, Perú. Materiales y métodos: Se colectaron biopsias gástricas de 500 pacientes diagnosticados con dispepsia. A partir de estas biopsias, se aislaron y cultivaron 273 cepas de H. pylori para confirmar la infección mediante el diagnóstico histológico y por cultivo. Finalmente, se analizó la susceptibilidad antimicrobiana mediante el método de microdilución en caldo y se evaluaron los perfiles de resistencia de cada antimicrobiano y los patrones de multirresistencia. Resultados: El diagnóstico de H. pylori por cultivo, comparado con la prueba histológica, reportó una sensibilidad del 83,8%, una especificidad del 89,9% y un área bajo la curva de 0,87 (IC95%: 0,84 a 0,90). La frecuencia de la infección en los servicios de gastroenterología del Hospital y la Clínica Cayetano Heredia fueron del 56,6% (237/419) y 44,4% (36/81), respectivamente. Según el Hospital/Clínica, se determinó la resistencia para amoxicilina (45,1%/29,6%), levofloxacino (71,8%/74,1%) y metronidazol (69,8%/63,0%). Los patrones de resistencia a múltiples antimicrobianos demostraron que las resistencias (dobles y triples) más frecuentes fueron con levofloxacino, metronidazol y amoxicilina. Conclusiones: La resistencia antimicrobiana de H. pylori ha aumentado con respecto a los años previos. Además, la resistencia múltiple de H. pylori presenta altas frecuencias en pacientes infectados. El método de microdilución en caldo podría ser implementado en los diferentes hospitales del Perú como una herramienta de vigilancia de la resistencia de H. pylori a los antimicrobianos.

ABSTRACT Objective: To analyze the antimicrobial susceptibility of Helicobacter pylori to 5 reference antibiotics, in a population of 500 dyspeptic patients from the Gastroenterology Service of the Cayetano Heredia Hospital (n = 419) and the Cayetano Heredia Clinic (n = 81) in Lima, Peru. Materials and methods: Gastric biopsies were collected from 500 patients diagnosed with dyspepsia. From these biopsies, 273 H. pylori strains were isolated and cultured to confirm H. pylori infection by histological and culture diagnosis. Finally, antimicrobial susceptibility was analyzed using the broth microdilution method, and the resistance profiles of each antimicrobial and multi-resistance patterns were evaluated by statistical analysis. Results: The diagnosis of H. pylori infection by culture, compared to histological testing, reported a sensitivity of 83.8%, a specificity of 89.9% and an area under the curve (AUC) of 0.87 (95% CI: 0.84 to 0.90). The frequency of infection in the gastroenterology services of the Cayetano Heredia Hospital and Clinic was 56.6% (237/419) and 44.4% (36/81), respectively. An increase in antimicrobial resistance to Amoxicillin (45.1% / 29.6%), Levofloxacin (71.8%/ 74.1%) and Metronidazole (69.8% / 63.0%) was found in the Hospital and the Clinic, respectively. Multiple resistance patterns showed that the most frequent resistance (double and triple) was to Levofloxacin, Metronidazole and Amoxicillin. Conclusions: The antimicrobial resistance of H. pylori has increased compared to that reported in previous years. Furthermore, H. pylori multiple resistance presents high frequencies in infected patients. The broth microdilution method could be implemented in different hospitals in Peru as a surveillance tool for H. pylori antimicrobial resistance.

Evaluación de la toxicidad de chalconas sintéticas con potencial anti-Leishmania en ratones BALB/c / Toxicity assessment of synthetic chalcones with antileishmanial potential in BALB/c mice

RESUMEN Objetivo: Evaluar la toxicidad de tres chalconas sintéticas administradas por vía intraperitoneal en ratones BALB/c. Materiales y métodos: La dosis letal media (DL50) se estimó por el método Up-and-Down de Dixon. La toxicidad subcrónica de las chalconas se evaluó a 20 y 40 mg/kg por 21 días. Se evaluó el efecto tóxico a nivel de comportamiento, fisiológico, bioquímico e histológico. Resultados: La chalcona 43 generó moco en las heces, daño visceral (hígado) y alteración en el coeficiente de órganos (riñón, p = 0,037 y cerebro, p = 0,008) en comparación con el grupo control. Además, en el análisis histológico se observó que esta chalcona produjo edema, inflamación y necrosis en los órganos evaluados, aunque no hubo diferencia significativa con el control. Todos los parámetros bioquímicos no difirieron significativamente entre los grupos de tratamiento a dosis de 40 mg/kg y el control. Conclusiones: La DL50 para las tres chalconas fue superior a 550 mg/kg de peso corporal. Las chalconas 40 y 42 son relativamente no tóxicas. Ambas pueden considerarse seguras para la aplicación vía intraperitoneal en ratones BALB/c y, en consecuencia, son posibles candidatas para ser usadas en el tratamiento contra las leishmaniosis.

ABSTRACT Objective: To evaluate the toxicity of three synthetic chalcones administered intraperitoneally to BALB/c mice. Materials and methods: The median lethal dose (LD50) was estimated by Dixon's Up-and-Down method. Subchronic toxicity of chalcones was evaluated at 20 and 40 mg/kg for 21 days. Behavioral, physiological, biochemical, and histological toxic effects were evaluated. Results: Chalcone 43 produced mucus in feces, visceral damage (liver) and alterations in organ coefficient (kidney, p = 0.037 and brain, p = 0.008) when compared to the control group. In addition, histological analysis showed that this chalcone produced edema, inflammation and necrosis in the evaluated organs, although there was no significant difference with the control. None of the biochemical parameters differed significantly between the treatment groups at 40 mg/kg dose and the control. Conclusions: The LD50 for all three chalcones was greater than 550 mg/kg of body weight. Chalcones 40 and 42 were found to be relatively non-toxic. Both can be considered safe for intraperitoneal application in BALB/c mice and, consequently, are potential candidates for use in the treatment of leishmaniasis.

Structural Characterization and Anti-infective Activity of 9,10-Seco-29-norcycloartane Glycosides Isolated from the Flowers of the Peruvian Medicinal Plant Cordia lutea.

Six new secocycloartane glycosides (1-6) were isolated from the ethanol extract of the flowers of Cordia lutea Lam. on the basis of bioassay-guided fractionation. Their structures were determined by the application of NMR and MS data analyses together with X-ray crystallographic analyses for compounds 1 and 2. Compounds 1-6 represent the first examples of 9,10-seco-29-norcycloartane glycosides. These compounds showed significant in vitro anti-Helicobacter pylori activity, and no activity against either Escherichia coli or Pseudomonas aeruginosa. Significant activity was observed for 5 and 6 against Staphylococcus aureus. All compounds displayed weak cytotoxicity against RAW 264.7 cells. The in vitro antileishmanial and antiplasmodial activities of 1-6 were also evaluated.

Prospecting Peptides Isolated From Black Soldier Fly (Diptera: Stratiomyidae) With Antimicrobial Activity Against Helicobacter pylori (Campylobacterales: Helicobacteraceae).

Helicobacter pylori (Marshall & Goodwin) is a widespread human pathogen that is acquiring resistance to the antibiotics used to treat it. This increasing resistance necessitates a continued search for new antibiotics. An antibiotic source that shows promise is animals whose immune systems must adapt to living in bacteria-laden conditions by producing antibacterial peptides or small molecules. Among these animals is the black soldier fly (BSF; Hermetia illucens Linnaeus), a Diptera that colonizes decomposing organic matter. In order to find anti-H. pylori peptides in BSF, larvae were challenged with Escherichia coli (Enterobacteriales: Enterobacteriaceae). Small peptides were extracted from hemolymph and purified using solid-phase extraction, molecular weight cutoff filtration and two rounds of preparative high performance liquid chromatography (HPLC). The anti-H. pylori fraction was followed through the purification process using the inhibition zone assay in brain-heart infusion agar, while peptides from uninoculated larvae had no activity. The inhibition halo of the active sample was comparable to the action of metronidazole in the inhibition zone assay. The purified sample contained four peptides with average masses of approximately 4.2 kDa that eluted together when analyzed by HPLC-mass spectrometry. The peptides likely have similar sequences, activity, and properties. Therefore, BSF produces inducible antibacterial peptides that have in vitro activity against H. pylori, which highlights BSF's position as an important target for further bioprospecting.

Identification and characterization of compounds from Chrysosporium multifidum, a fungus with moderate antimicrobial activity isolated from Hermetia illucens gut microbiota.

The gut microbiota of insects is composed of a wide range of microorganisms which produce bioactive compounds that protect their host from pathogenic attack. In the present study, we isolate and identify the fungus Chrysosporium multifidum from the gut of Hermetia illucens larvae. Extract from C. multifidum culture broth supernatant showed moderate activity against a strain of methicillin-resistant Staphylococcus aureus (MRSA). Bioguided isolation of the extract resulted in the characterization of six α-pyrone derivatives (1-6) and one diketopiperazine (7). Of these compounds, 5,6-dihydro-4-methoxy-6-(1-oxopentyl)-2H-pyran-2-one (4) showed the greatest activity (IC50 = 11.4 ± 0.7 µg/mL and MIC = 62.5 µg/mL) against MRSA.

[Antimicrobial susceptibility and mutations in the 23S rRNA gen of Helicobacter pylori in dyspeptic patients]. / Susceptibilidad antimicrobiana y mutaciones en el gen ARNr 23S de Helicobacter pylori en pacientes dispépticos.

In order to evaluate antimicrobial susceptibility and detect specific mutations in the 23S rRNA gene in Helicobacter pylori strains, a cross-sectional study was performed on 95 patients with dyspepsia treated in a private clinic in Lima. Antrum biopsies were collected by endoscopy for isolation and evaluation of antimicrobial susceptibility using the broth microdilution method. The detection of specific mutations was developed by PCR-RFLP. The percentage of infection by Helicobacter pylori was 46.3%. Resistance values of 52.3% to clarithromycin, 29.6% to metronidazole, 45.5% to levofloxacin, and 4.6% to amoxicillin were observed. The percentage of specific A2142G and A2143G mutations associated with clarithromycin resistance was 43.5%. In conclusion, we found that antimicrobial resistance rates and the percentage of Helicobacter pylori strains circulating in a private clinic in Lima were high.

Con el objetivo de evaluar la susceptibilidad antimicrobiana y detectar mutaciones puntuales en el gen ARNr 23S en cepas de Helicobacter pylori se realizó un estudio transversal que incluyó a 95 pacientes con dispepsia atendidos en una clínica privada de Lima. Mediante endoscopía se colectaron biopsias de antro para el aislamiento de cepas de Helicobacter pylori para la evaluación de la susceptibilidad antimicrobiana empleando la técnica de microdilución en caldo. La detección de mutaciones puntuales se desarrolló mediante PCR-RFLP. El porcentaje de infección por Helicobacter pylori fue de 46,3%, se observaron valores de resistencia de 52,3% a claritromicina, 29,6% a metronidazol, 45,5% a levofloxacino y 4,6% a amoxicilina. El porcentaje de mutaciones puntuales A2142G y A2143G asociados a resistencia a claritromicina fue 43,5%. En conclusión, encontramos que las tasas de resistencia antimicrobiana y el porcentaje de cepas de Helicobacter pylori circulantes en una clínica privada de Lima fueron elevadas.

Susceptibilidad antimicrobiana y mutaciones en el gen ARNr 23S de Helicobacter pylori en pacientes dispépticos / Antimicrobial susceptibility and mutations in the 23S rRNA gen of Helicobacter pylori in dyspeptic patients

RESUMEN Con el objetivo de evaluar la susceptibilidad antimicrobiana y detectar mutaciones puntuales en el gen ARNr 23S en cepas de Helicobacter pylori se realizó un estudio transversal que incluyó a 95 pacientes con dispepsia atendidos en una clínica privada de Lima. Mediante endoscopía se colectaron biopsias de antro para el aislamiento de cepas de Helicobacter pylori para la evaluación de la susceptibilidad antimicrobiana empleando la técnica de microdilución en caldo. La detección de mutaciones puntuales se desarrolló mediante PCR-RFLP. El porcentaje de infección por Helicobacter pylori fue de 46,3%, se observaron valores de resistencia de 52,3% a claritromicina, 29,6% a metronidazol, 45,5% a levofloxacino y 4,6% a amoxicilina. El porcentaje de mutaciones puntuales A2142G y A2143G asociados a resistencia a claritromicina fue 43,5%. En conclusión, encontramos que las tasas de resistencia antimicrobiana y el porcentaje de cepas de Helicobacter pylori circulantes en una clínica privada de Lima fueron elevadas.

ABSTRACT In order to evaluate antimicrobial susceptibility and detect specific mutations in the 23S rRNA gene in Helicobacter pylori strains, a cross-sectional study was performed on 95 patients with dyspepsia treated in a private clinic in Lima. Antrum biopsies were collected by endoscopy for isolation and evaluation of antimicrobial susceptibility using the broth microdilution method. The detection of specific mutations was developed by PCR-RFLP. The percentage of infection by Helicobacter pylori was 46.3%. Resistance values of 52.3% to clarithromycin, 29.6% to metronidazole, 45.5% to levofloxacin, and 4.6% to amoxicillin were observed. The percentage of specific A2142G and A2143G mutations associated with clarithromycin resistance was 43.5%. In conclusion, we found that antimicrobial resistance rates and the percentage of Helicobacter pylori strains circulating in a private clinic in Lima were high.

Profiling of Hura crepitans L. latex by ultra-high-performance liquid chromatography/atmospheric pressure chemical ionisation linear ion trap Orbitrap mass spectrometry.

INTRODUCTION: The phytochemistry of the latex of Hura crepitans L. (Euphorbiaceae), a widespread tree in the Amazonian forest having many uses, is little known. Only huratoxin, a daphnane diterpene orthoester, has been described despite the high pharmacological potential of this kind of compounds. Glucosphingolipids (cerebrosides) are also known to be distributed in Euphorbiaceae latexes. OBJECTIVE: To tentatively identify daphnanes diterpenes and cerebrosides in the latex of H. crepitans. METHODS: An ethanolic extract of the lyophilised latex of H. crepitans was analysed by ultra-high-performance liquid chromatography (UHPLC) coupled with positive and negative atmospheric pressure chemical ionisation high-resolution mass spectrometry (APCI-HRMS) method using a quadrupole/linear ion trap/Orbitrap (LTQ-Orbitrap). Tandem mass spectrometry (MS/MS) spectra were recorded by two different fragmentation modes: collision induced dissociation (CID) and higher-energy collisional dissociation (HCD). RESULTS: The analysis of CID- and HCD-MS/MS spectra allowed to propose fragmentation patterns for daphnane esters and cerebrosides and highlight diagnostic ions in positive and negative ion modes. A total of 34 compounds including 24 daphnane esters and 10 cerebrosides have been tentatively annotated. Among them, 17 daphnane diterpenes bearing one or two acyl chains are new compounds and the cerebrosides are described in the genus Hura for the first time. CONCLUSION: This study revealed the chemical constituents of the latex of H. crepitans and particularly its richness and chemical diversity in daphnane diterpenes, more frequently encountered in the species of Thymelaeaceae.

Anti-Helicobacter pylori Properties of the Ant-Venom Peptide Bicarinalin.

The venom peptide bicarinalin, previously isolated from the ant Tetramorium bicarinatum, is an antimicrobial agent with a broad spectrum of activity. In this study, we investigate the potential of bicarinalin as a novel agent against Helicobacter pylori, which causes several gastric diseases. First, the effects of synthetic bicarinalin have been tested against Helicobacter pylori: one ATCC strain, and forty-four isolated from stomach ulcer biopsies of Peruvian patients. Then the cytoxicity of bicarinalin on human gastric cells and murine peritoneal macrophages was measured using XTT and MTT assays, respectively. Finally, the preventive effect of bicarinalin was evaluated by scanning electron microscopy using an adherence assay of H. pylori on human gastric cells treated with bicarinalin. This peptide has a potent antibacterial activity at the same magnitude as four antibiotics currently used in therapies against H. pylori. Bicarinalin also inhibited adherence of H. pylori to gastric cells with an IC50 of 0.12 µg·mL-1 and had low toxicity for human cells. Scanning electron microscopy confirmed that bicarinalin can significantly decrease the density of H. pylori on gastric cells. We conclude that Bicarinalin is a promising compound for the development of a novel and effective anti-H. pylori agent for both curative and preventive use.

Macromolecular biosynthetic parameters and metabolic profile in different life stages of Leishmania braziliensis: Amastigotes as a functionally less active stage.

It was recently hypothesized that Leishmania amastigotes could constitute a semi-quiescent stage characterized by low replication and reduced metabolic activity. This concept developed with Leishmania (Leishmania) mexicana and Leishmania (Leishmania) major models might explain numerous clinical and sub-clinical features of Leishmania (Viannia) braziliensis infections, like reactivation of the disease, non-response to chemotherapy or asymptomatic infections. We compared here in vitro the proliferative capability of L. (V.) braziliensis amastigotes and promastigotes, assessed the expression of key molecular parameters and performed metabolomic analysis. We found that contrary to the highly proliferative promastigotes, amastigotes (axenic and intracellular) do not show evidence of extensive proliferation. In parallel, amastigotes showed a significant decrease of (i) the kDNA mini-circle abundance, (ii) the intracellular ATP level, (iii) the ribosomal components: rRNA subunits 18S and 28S α and ribosomal proteins RPS15 and RPL19, (iv) total RNA and protein levels. An untargeted metabolomic study identified clear differences between the different life stages: in comparison to logarithmic promastigotes, axenic amastigotes showed (a) a strong decrease of 14 essential and non-essential amino acids and eight metabolites involved in polyamine synthesis, (b) extensive changes in the phospholipids composition and (c) increased levels of several endogenous and exogenous sterols. Altogether, our results show that L. (V.) braziliensis amastigotes can show a phenotype with negligible rate of proliferation, a lower capacity of biosynthesis, a reduced bio-energetic level and a strongly altered metabolism. Our results pave the way for further exploration of quiescence among amastigotes of this species.

A new phthalide derivative from Peperomia nivalis.

One new phthalide (1) was isolated from aerial parts of Peperomia nivalis, along with known compounds (2 and 3), reported in this species for the first time. The structure of the new compound was characterised on the basis of 1D (1H and 13C NMR), 2D (COSY, HMQC, HMBC and NOESY) NMR and high-resolution mass spectral (HRMS) data. Compound 2 was isolated from a natural source for the first time but previously synthesised. Compounds 1-3 were evaluated for their anti-Helicobacter pylori and anti-Plasmodium falciparum activities. Compound 1 showed moderate activities against H. pylori (MIC 47.5 µM) and the F32-Tanzania strain of P. falciparum (IC50 8.5 µM). Compounds 2 and 3 exhibited weak anti-H. pylori activity (MIC 241.3 and 237.6 µM, respectively) and were inactive against P. falciparum.

La captación de yodo I-131 como herramienta útil en el estudio de la función tiroidea / The uptake of iodine I-131 as a useful tool in the study of thyroid function

Se realizó un estudio en el Departamento de Medicina Nuclear del Hospital General Docente Dr Agostinho Neto de Guantánamo durante el año 2013 con el objetivo de valorar en el menor tiempo posible el resultado de la captación de yodo radioactivo (I-131), encontrando que esta prueba es eficaz en el diagnóstico temprano de la función tiroidea y tiene como ventaja un diagnóstico temprano que permite imponer el tratamiento en el menor tiempo posible contribuyendo a elevar la calidad de vida de estos pacientes. Se emiten conclusiones y recomendaciones(AU)

A study was performed at the Department of Nuclear Medicine at the General Teaching Hospital Dr Agostinho Neto Guantanamo in 2013 with the aim of assessing in the shortest time possible results of the up taking of radioactive iodine (I-131), finding that, this test is effective in the early diagnosis of thyroid function and its advantage early diagnosis allows impose treatment in the shortest possible time helping to raise the quality of life of these patients. Conclusions and recommendations are issued(AU)

Leishmanicidal compounds and potent PPARγ activators from Renealmia thyrsoidea (Ruiz & Pav.) Poepp. & Endl.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves and rhizomes of Renealmia thyrsoidea (Ruiz & Pav.) Poepp. & Endl. traditionally used in the Yanesha pharmacopoeia to treat skin infections such as leishmaniasis ulcers, or to reduce fever were chemically investigated to identify leishmanicidal compounds, as well as PPARγ activators. METHODS: Compounds were isolated through a bioassay-guided fractionation and their structures were determined via detailed spectral analysis. The viability of Leishmania amazonensis axenic amastigotes was assessed by the reduction of tetrazolium salt (MTT), the cytotoxicity on macrophage was evaluated using trypan blue dye exclusion method, while the percentage of infected macrophages was determined microscopically in the intracellular macrophage-infected assay. The CD36, mannose receptor (MR) and dectin-1 mRNA expression on human monocytes-derived macrophages was evaluated by quantitative real-time PCR. RESULTS: Six sesquiterpenes (1-6), one dihydrobenzofuranone (7) and four flavonoids (8-11) were isolated from the leaves. Alongside, two flavonoids (12-13) and five diarylheptanoids (14-18) were identified in the rhizomes. Leishmanicidal activity against Leishmania amazonensis axenic amastigotes was evaluated for all compounds. Compounds 6, 7, and 11, isolated from the leaves, showed to be the most active derivatives. Diarylheptanoids 14-18 were also screened for their ability to activate PPARγ nuclear receptor in macrophages. Compounds 17 and 18 bearing a Michael acceptor moiety strongly increased the expression of PPARγ target genes such as CD36, Dectin-1 and mannose receptor (MR), thus revealing interesting immunomodulatory properties. CONCLUSIONS: Phytochemical investigation of Renealmia thyrsoidea has led to the isolation of leishmanicidal compounds from the leaves and potent PPARγ activators from the rhizomes. These results are in agreement with the traditional uses of the different parts of Renealmia thyrsoidea.

In vitro and in vivo activity of benzo[c]phenanthridines against Leishmania amazonensis.

Seven benzo[c]phenanthridines, synthetic or isolated from Zanthoxylum rhoifolium root bark, were evaluated against Leishmania amazonensis axenic amastigotes. Five of them were considered leishmanicidal, with IC50 values ranging from 0.03 to 0.54 µM, and were evaluated on intramacrophagic amastigotes of L. amazonensis. Chelerythrine displayed the best activity (IC50=0.5 µM), which was in the same range as the reference compound amphotericin B (IC50=0.4 µM). In vivo studies with chelerythrine, avicine, and fagaridine on a model of mice cutaneous leishmaniasis resulted in the identification of fagaridine as the most active compound. Fagaridine decreased the parasitic burden more than 50% at the 3rd and 6th weeks after the end of treatment.

Dihydrochalcones and benzoic acid derivatives from Piper dennisii.

Two new dihydrochalcones (1, 2), as well as eight known compounds, piperaduncin C (3), 2',6'-dihydroxy-4'-methoxydihydrochalcone (4), 4,2',6'-trihydroxy-4'-methoxydihydrochalcone (5), 4-hydroxy-3,5-bis(3-methyl-2-butenyl)-benzoic acid (6), 3,5-bis(3-methyl-2-butenyl)-4-methoxybenzoic acid (7), 4-hydroxy-3-(3-methyl-2-butenoyl)-5-(3-methyl-2-butenyl)-benzoic acid (8), 2,2-dimethyl-8-(3-methyl-2-butenyl)-2H-1-chromene-6-carboxylic acid (9), and 3-(3',7'-dimethyl-2',6'-octadienyl)-4-methoxybenzoic acid (10) were isolated from the leaves of Piper dennisii Trelease (Piperaceae), using a bioassay-guided fractionation to determine their antileishmanial potential. Among them, compound 10 exhibited the best antileishmanial activity (IC50 = 20.8 µM) against axenic amastigote forms of Leishmania amazonensis, with low cytotoxicity on murine macrophages. In the intracellular macrophage-infected model, compound 10 proved to be more active (IC50 = 4.2 µM). The chemical structures of compounds 1-10 were established based on the analysis of the spectroscopic data.

New salicylamide and sulfonamide derivatives of quinoxaline 1,4-di-N-oxide with antileishmanial and antimalarial activities.

Continuing with our efforts to identify new active compounds against malaria and leishmaniasis, 14 new 3-amino-1,4-di-N-oxide quinoxaline-2-carbonitrile derivatives were synthesized and evaluated for their in vitro antimalarial and antileishmanial activity against Plasmodium falciparum Colombian FCR-3 strain and Leishmania amazonensis strain MHOM/BR/76/LTB-012A. Further computational studies were carried out in order to analyze graphic SAR and ADME properties. The results obtained indicate that compounds with one halogenous group substituted in position 6 and 7 provide an efficient approach for further development of antimalarial and antileishmanial agents. In addition, interesting ADME properties were found.

Comparative gene expression analysis throughout the life cycle of Leishmania braziliensis: diversity of expression profiles among clinical isolates.

BACKGROUND: Most of the Leishmania genome is reported to be constitutively expressed during the life cycle of the parasite, with a few regulated genes. Inter-species comparative transcriptomics evidenced a low number of species-specific differences related to differentially distributed genes or the differential regulation of conserved genes. It is of uppermost importance to ensure that the observed differences are indeed species-specific and not simply specific of the strains selected for representing the species. The relevance of this concern is illustrated by current study. METHODOLOGY/PRINCIPAL FINDINGS: We selected 5 clinical isolates of L. braziliensis characterized by their diversity of clinical and in vitro phenotypes. Real-time quantitative PCR was performed on promastigote and amastigote life stages to assess gene expression profiles at seven time points covering the whole life cycle. We tested 12 genes encoding proteins with roles in transport, thiol-based redox metabolism, cellular reduction, RNA poly(A)-tail metabolism, cytoskeleton function and ribosomal function. The general trend of expression profiles showed that regulation of gene expression essentially occurs around the stationary phase of promastigotes. However, the genes involved in this phenomenon appeared to vary significantly among the isolates considered. CONCLUSION/SIGNIFICANCE: Our results clearly illustrate the unique character of each isolate in terms of gene expression dynamics. Results obtained on an individual strain are not necessarily representative of a given species. Therefore, extreme care should be taken when comparing the profiles of different species and extrapolating functional differences between them.