Tolerancia al plomo de aislamientos nativos de Pseudomonas spp. de aguas residuales del Valle de Aburrá / Tolerance lead of native pseudomonas spp. wastewater from Aburrá Valley

RESUMEN El plomo (Pb) es un metal pesado cuyas características físico-químicas lo convierten en un contaminante ambiental persistente, bioacumulable y de alta toxicidad. La biorremediación surge como una alternativa con múltiples ventajas en comparación con los tratamientos convencionales para remover contaminantes como metales pesados de aguas residuales, basándose en las capacidades de tolerancia y mecanismos de resistencia de los microorganismos. Con el fin de conocer la tolerancia de Pseudomonas spp. al plomo presente en aguas contaminadas, se obtuvieron cuatro aislados nativos, procedentes de aguas residuales colectadas en el río del Valle de Aburrá (zona norte), los cuales se caracterizaron bioquímicamente. Se realizaron bioensayos de tolerancia en diferentes concentraciones de plomo por difusión en agar, como prueba tamiz, y determinación de la concentración mínima inhibitoria, determinando la viabilidad del microorganismo en cada exposición. No se presentó diferencia significativa para la tolerancia al plomo entre los aislados, identificados bioquímicamente como Pseudomonas aeruginosa, ni entre las diferentes concentraciones de plomo a las cuales fueron expuestos los aislados. A partir de estos resultados, se discute a cerca de los mecanismos reportados por diferentes autores, mediante los cuales Pseudomonas spp. puede actuar en presencia de Plomo. De esta manera, se concluye que los aislados de Pseudomonas spp. presentan mecanismos de tolerancia y/o resistencia hasta concentraciones de 2500 mg/L en presencia de nitrato de plomo, como potenciales agentes que pueden integrarse en procesos que impulsan nuevas tecnologías de biorremediación.

ABSTRACT Lead (Pb) is a heavy metal whose physicochemical characteristics make it a persistent environmental pollutant, bioaccumulable and highly toxic. Bioremediation emerges as an alternative with multiple advantages compared to conventional treatments to remove contaminants such as heavy metals from wastewater, based on the tolerance capacities and/or resistance mechanisms of microorganisms. In order to know the tolerance of Pseudomonas spp. to the lead present in contaminated waters, four native isolates were obtained, coming from wastewater collected in the north from Aburrá Valley River, which were characterized biochemically. Tolerance bioassay was carried out in different concentrations of lead by agar diffusion, as a screening test, and determination of the minimum inhibitory concentration, determining the viability of the microorganism in each exposure. There was no significant difference for lead tolerance between the isolates, identified biochemically as Pseudomonas aeruginosa, nor between the different concentrations of lead to which the isolates were exposed. From these results, we discuss about the mechanisms reported by different authors, by means of which Pseudomonas spp. can act in the presence of lead. In this way, it is concluded that the isolates of Pseudomonas spp. they present tolerance and/or resistance mechanisms up to 2500 mg/L in the presence of lead nitrate, as potential agents that can be integrated into processes that promote new bioremediation technologies.

Relación entre actividades de tiempo libre y cognición en adultos mayores: una revisión de estudios argentinos e iberoamericanos / Relationship between leisure activities and cognition in elderly adults: a review of argentine and Iberoamerican studies

El envejecimiento poblacional implica un desafío para la salud pública por las patologías cuyos casos aumentan con la extensión de la vida. Se ha propuesto que ciertas actividades de la vida diaria (AVDs) avanzadas de tiempo libre poseen un efecto bené+co en la cognición de los adultos mayores. El objetivo de este trabajo fue relevar estudios empíricos presentando evidencia respecto a la relación entre dichas actividades y el funcionamiento cognitivo, para países iberoamericanos. Se incluyeron trabajos escritos en español, portugués e inglés, de enero de 2012 a mayo de 2017, involucrando a adultos de 60 y más años de edad no institucionalizados. Se hallaron 15 trabajos. Considerados en su conjunto, existiría evidencia de una relación entre las mencionadas actividades y el rendimiento cognitivo. Los trabajos de diseño prospectivo y los de intervención indicarían que la realización de dichas actividades avanzadas incide bene+ciosamente en el funcionamiento cognitivo.

Population aging implies a challenge to public health for the pathologies whose cases increase with the extension of life. It has been proposed that certain leisure advanced activities of daily living (ATLs) have a bene+cial effect on the cognition of the elderly. The objective of this work was to relieve empirical studies presenting evidence regarding the relationship between these activities and cognitive functioning, for Iberoamerican countries. Works written in Spanish, Portuguese and English were included from January 2012 to May 2017, involving non-institutionalized adults aged 60 and over. Fifteen papers were found. Considered as a whole, there would be evidence of a relationship between these activities and cognitive performance. Prospective design and interventional studies would indicate that such advanced activities has a bene+cial impact on cognitive functioning.

Salud Colectiva y Psicoanálisis: entrecruzando conceptos en busca de políticas públicas potentes / Collective Health and Psichoanalisis: intermingling concepts in search of strong public policies

Este artículo presenta una reflexión sobre la posible utilización de categorías oriundas de la salud colectiva y del psicoanálisis para enfrentar los nuevos dilemas de las prácticas de salud, en la periferia de las grandes ciudades, en el mundo contemporáneo. Valiéndose de la recomendación gadameriana de volver al pasado y revisar las tradiciones, el texto recurre y rediscute algunos conceptos ya clásicos en sus propios campos disciplinares pero que se reactualizan y ganan otra relevancia colocados en contraste, siendo, por lo tanto, reinterpretados. Finalmente se apuntan algunos ejemplos de aplicación de los mismos en busca de la superación de algunos obstáculos identificados en la implementación de políticas públicas de salud: vulnerabilidad, búsqueda activa, ampliación de la clínica, significaciones imaginarias y subjetividad del equipo.

This article presents a reflexion about the possible use of categories belonging to collective health and psichoanalisis to face the new dilemmas of the health practices nowadays in the suburbs of big cities in the contemporary world. Taking into account the gadamerian recommendation of coming back to the past and reviewing the traditions, this paper reformulates some classical concepts within their disciplinary fields which are herein updated acquiring relevance at being reinterpreted. Finally, some examples are given regarding the application of these concepts to overcome some of the obstacles identified in the implementation of health public policies: vulnerability, active search, clinical spread and imaginary significations and team subjectivity.

How to distinguish normal liver from chronic hepatitis in anti-HCV positive individuals with normal alanine aminotranferase levels

The aim of this study was to characterize the biochemical, virological and histological profile of patients with HCV infection and persistently normal alanine aminotransferase levels (PNALT) in order to discriminate between normal liver and chronic hepatitis. Twenty eight anti-HCV positive patients with PNALT were studied. Twelve (42.9) patients showed normal liver while 16 (57.1) had chronic hepatitis. In patients with normal liver, the mean of ALT level differed from patients with chronic hepatitis (16.3 IU/L versus 25.6 IU/L, p 0.000089). By considering different ALT values as upper normal limit, sensitivity, specificity, positive and negative predictive values were calculated and the value of 18 IU/l showed 88, 90, 94 and 82, respectively, in predicting chronic hepatitis. In conclusion, patients with normal liver had lower ALT levels than those with chronic hepatitis and by establishing 18 IU/L as a new upper limit of normal ALT value, it was possible to differentiate normal liver from chronic hepatitis in HCV patients with PNALT (AU)#S

Relationship between diversity of hepatitis C quasispecies and histological severity of liver disease

The aim of this work to assess in the diversity of hepatitis C virus (HCV) quasispecies is related to histological severity and duration of infection in a cohort of untreated patients with an estimated onset of the disease. A total of 27 patients with diagnosis of chronic liver disease and history of blood transfusion (n = 16) or intravenous drug use (IDU) (n = 11) were included. All were anti-HCV positive and had detectable serum drug injection. Patients who consumed drugs for more than 2 years, or were coinfected with HBV or HIV were excluded. History of alcohol intake (> 80 g/day), ALT level and age at infection were recorded. Histological assessment of grading and staging was performed according to knodell score. The quasispecies diversity was investigated by single strand conformation polymorphism (SSCP) target to HVR-E2 region and SSCP pattern was evaluated as a single or multiple bands. The number of quasispecies did not correlate with estimated duration of the disease. Patients who acquired hepatitis C by blood transfusion did not differ in number of bands from patients who were IDU. There was no correlation between the heterogeneity of HCV quasispecies and age, serum ALT, Knodell score, HAI and fibrosis. In clonclusion the quasiespecies diversity of E2 had no correlation with grade and stage of chronic HCV infection and the presence of quasispecies was independent of the duration of the disease.

In vivo down regulation of HIV replication after hepatitis C superinfection

There are increasing molecular and clinical evidences that the effects of human immunodeficiency virus (HIV) infection can be modified by coinfection with other viruses. The objective was to investigate the viral interaction between HIV and hepatitis C virus (HCV) after HCV superinfection. A 16 year-old pregnant woman was evaluated because of icteric acute hepatitis. Admission laboratory tests showed the following results: ALT 877 IU/L; AST 1822 1822 IU/L; bilirubin 6.79 mg/dl. Diagnosis of acute HCV was based on detection of serum HCV RNA by PCR and anti-HCV seroconversion. ELISA for anti HIV testing was positive and confirmed by western blot. Serum markers for other viruses were negative. The patient was followed during 19 months; serum samples were taken monthly during this period for detection of plasma HIV and HCV RNA. Levels of plasma HIV-RNA were positive in all samples ttested before and after the onset of acute hepatitis C. Six months later and a for two month period, and 13 months later for a period of one month HIV viremia was undetectable; then HIV-RNA in plasma was detectable again. In conclusion, HCV superinfection may have temporarily interfered with HIV replication in our patient. The following observations support our hypothesis: it has been demonstrated that HIV-1 replication is suppressed by HCV core protein which has transcriptional regulation properties of several viral and cellular promoters. Clinical implications of this event are not generally known and the interaction between these two viruses in dual infections is worth considering.

Genomic and phylogenetic analysis of hapatitis C virus strains from Argentina

HCV genomic characterization was performed by nucleotide sequence analysis (n=50) combined with restriction fragment length polymorphism (RFLP) of the 5'UTR region in 82 isolates coresponding to different Argentine groups. Genotype 1 was detected in 70.7 percent of the samples (58 out of 82), genotype 2 in 21.9 percent (18 of 82) and genotypes 3 in the remaining 6 sera (7.3 percent). HCV ib subtype contributed with 35.3 percent to the whole population studied (29 of 82) and was detected in 6 out of 21 sporadic cases. Besides their epidemiological significance, these results should be taken into account when future vaccines are considered on the basis of geographical HCV genotypic prevalence.

Problematica de la infeccion por el virus de la hepatitis C en donantes de sangre: evaluacion clinico-epidemiologica, virologica e histologica / The problem of hepatitis C virus infection in blood donors: clinico-epidemiological, virological and histological evaluation

El objetivo fue establecer prospectivamente el significado clínico de la infección por el virus de la hepatitis C (HCV) en donantes voluntarios de sangre. Fueron evaluados 248 donantes de acuerdo al resultado definitivo del anti-HCV, analizándose los factores de riesgo, niveles de transaminasas (ALT), ARN del virus C por PCR y biopsia hepática. De los 248 donantes 132 (53,22 por ciento) resultaron verdaderos anti-HCV+ y 116 (46,77 por ciento) anti-HCV(-), 198 eran hombres y 50 mujeres, edad promedio 33,4 años. Factores de riesgo en el grupo anti-HCV+: drogadición intravenosa (22 por cento vs 1,72 por ciento) (p 0,0000), cirugía mayor (20,4 por ciento vs 12 por ciento), tatuajes (12,1 por ciento vs 4,3 por ciento), consumo de drogas no endovenosas (17,4 vs 4,3 por ciento) ( p 0,001) y promiscuidad sexual o enfermedades de transmisión sexual (25,7 por ciento vs 11,2) (p 0,003). En el grupo anti-HCV+ se encontró por lo menos un factor de riesgo en el 76,5 por ciento de los casos vs un 34,4 por ciento en el grupo anti-HCV(-) (p 0,000). Aceptaron biopsia hepática 71 donantes HCV(+) y el 69 por ciento (49 pts) presentó ALT elevadas. El 85,9 por ciento (61) de los pts. presentó hepatitis crónica, el 11,2 por ciento (8) hallazgos mínimos incaracterísticos 11,2 por ciento (8) y el 2,8 por ciento (2) hepatitis aguda. El 76 por ciento (54) de los pts. fueron PCR-HCV(+). El promedio del score de Knodell fue 6,75 (DS 3,51). En conclusión, en el 76,5 por ciento de los donantes (HCV(+) se encontró por lo menos un factor de riesgo (22 por ciento de antecedentes de DIV); el 85,9 por ciento presentó lesiones crónicas en la biopsia independientemente de los niveles de transaminasas y la presencia de ALT normal no excluyó lesión hepática.