ABSTRACT
Insulin regulates the l-arginine/nitric oxide (NO) pathway in human umbilical vein endothelial cells (HUVECs), increasing the plasma membrane expression of the l-arginine transporter hCAT-1 and inducing vasodilation in umbilical and placental veins. Placental vascular relaxation induced by insulin is dependent of large conductance calcium-activated potassium channels (BKCa), but the role of KCa channels on l-arginine transport and NO synthesis is still unknown. The aim of this study was to determine the contribution of KCa channels in both insulin-induced l-arginine transport and NO synthesis, and its relationship with placental vascular relaxation. HUVECs, human placental vein endothelial cells (HPVECs) and placental veins were freshly isolated from umbilical cords and placenta from normal pregnancies. Cells or tissue were incubated in absence or presence of insulin and/or tetraethylammonium, 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole, iberiotoxin or NG-nitro-l-arginine methyl ester. l-Arginine uptake, plasma membrane polarity, NO levels, hCAT-1 expression and placenta vascular reactivity were analyzed. The inhibition of intermediate-conductance KCa (IKCa) and BKCa increases l-arginine uptake, which was related with protein abundance of hCAT-1 in HUVECs. IKCa and BKCa activities contribute to NO-synthesis induced by insulin but are not directly involved in insulin-stimulated l-arginine uptake. Long term incubation (8 h) with insulin increases the plasma membrane hyperpolarization and hCAT-1 expression in HUVECs and HPVECs. Insulin-induced relaxation in placental vasculature was reversed by KCa inhibition. The results show that the activity of IKCa and BKCa channels are relevant for both physiological regulations of NO synthesis and vascular tone regulation in the human placenta, acting as a part of negative feedback mechanism for autoregulation of l-arginine transport in HUVECs.
Subject(s)
Intermediate-Conductance Calcium-Activated Potassium Channels/metabolism , Large-Conductance Calcium-Activated Potassium Channels/metabolism , Nitric Oxide/metabolism , Umbilical Veins/metabolism , Adult , Arginine/metabolism , Cationic Amino Acid Transporter 1/metabolism , Cell Membrane/drug effects , Cell Membrane/metabolism , Endothelium, Vascular/drug effects , Endothelium, Vascular/metabolism , Female , Human Umbilical Vein Endothelial Cells , Humans , Insulin/pharmacology , Intermediate-Conductance Calcium-Activated Potassium Channels/antagonists & inhibitors , Large-Conductance Calcium-Activated Potassium Channels/antagonists & inhibitors , Peptides/pharmacology , Placenta/drug effects , Placenta/metabolism , Potassium Channel Blockers/pharmacology , Pregnancy , Pyrazoles/pharmacology , Umbilical Veins/drug effects , Young AdultABSTRACT
Non-O1, non-O139 Vibrio cholerae (NOVC) strains are an uncommon cause of gastroenteritis. However, they have been recently associated with severe extraintestinal infections in immunocompromised hosts. Among them, bacteremia in cirrhotic patients is noteworthy. We present the case of a 58-year-old woman with cirrhosis that developed septic shock, multiple organ failure and died four days after admission. Blood cultures yielded Gram-negative rods identified as Vibrio cholerae. Further serogrouping by slide agglutination and a negative PCR for ctxA gen confirmed the strain to be NOVC. Antimicrobial susceptibility testing showed sensitivity to ampicillin, chloramphenicol, tetracycline and ciprofloxacin; and resistance to trimethoprim-sulfamethoxazole. To the best of our knowledge, this is first report in Peru, described in the Hospital Nacional Dos de Mayo, of NOVC bacteremia.
Subject(s)
Bacteremia/microbiology , Cholera/microbiology , Liver Cirrhosis/complications , Vibrio cholerae O139/isolation & purification , Vibrio cholerae non-O1/isolation & purification , Bacteremia/epidemiology , Cholera/complications , Cholera/epidemiology , Disease Susceptibility , Drug Resistance, Multiple, Bacterial , Fatal Outcome , Female , Humans , Middle Aged , Multiple Organ Failure/etiology , Peptic Ulcer Hemorrhage/complications , Peru/epidemiology , Serotyping , Shock, Septic/etiologyABSTRACT
Vibrio cholerae serogrupo NO-O1/NO-O139 (VCNO) es causa infrecuente de gastroenteritis. Sin embargo, se le asocia a infección extra-intestinal severa en huéspedes inmunocomprometidos, y entre ellas, la bacteremia en pacientes con cirrosis hepática es digna de mención. A continuación, presentamos el caso de una mujer de 58 años, con el diagnóstico de cirrosis hepática de fondo, que desarrolló progresivamente choque séptico, disfunción orgánica múltiple y desenlace fatal al cuarto día de su admisión. Los resultados obtenidos post mortem, de los hemocultivos previamente tomados, aislaron bacilos gram negativos compatibles con Vibrio cholerae. Posteriormente, se identificó el serogrupo NO-O1/NO-O139, a través de aglutinación en placa y PCR negativo para el gen ctxA. El antibiograma mostró susceptibilidad conservada a ampicilina, cloranfenicol, tetraciclina y ciprofloxacino, con resistencia al trimetoprim-sulfametoxazol. El presente caso, descrito en el Hospital Nacional Dos de Mayo, es hasta la fecha, el primer reporte de bacteremia VCNO en el Perú.
Non-O1, non-O139 Vibrio cholerae (NOVC) strains are an uncommon cause of gastroenteritis. However, they have been recently associated with severe extraintestinal infections in immunocompromised hosts. Among them, bacteremia in cirrhotic patients is noteworthy. We present the case of a 58-year-old woman with cirrhosis that developed septic shock, multiple organ failure and died four days after admission. Blood cultures yielded Gram-negative rods identified as Vibrio cholerae. Further serogrouping by slide agglutination and a negative PCR for ctxA gen confirmed the strain to be NOVC. Antimicrobial susceptibility testing showed sensitivity to ampicillin, chloramphenicol, tetracycline and ciprofloxacin; and resistance to trimethoprim-sulfamethoxazole. To the best of our knowledge, this is first report in Peru, described in the Hospital Nacional Dos de Mayo, of NOVC bacteremia.
Subject(s)
Female , Humans , Middle Aged , Cholera/microbiology , Bacteremia/microbiology , Vibrio cholerae O139/isolation & purification , Vibrio cholerae non-O1/isolation & purification , Liver Cirrhosis/complications , Peru/epidemiology , Shock, Septic/etiology , Serotyping , Peptic Ulcer Hemorrhage/complications , Cholera/complications , Cholera/epidemiology , Bacteremia/epidemiology , Fatal Outcome , Drug Resistance, Multiple, Bacterial , Disease Susceptibility , Multiple Organ Failure/etiologyABSTRACT
The emergence of Enterobacteria producing carbapenemases of type New Delhi Metalo beta-lactamases (NDM), >represent, today, a real problem of world public health. The presence of this resistance mechanism limits or nullifies the therapeutic options to combat these bacteria. In Latin America, the figures are getting higher, as they are reported in Guatemala, Colombia, Chile, Argentina, among others. Peru has not, to date, described the presence of this resistance pattern; however for several years it has been presumed to exist. Nine cases of Klebsiella pneumoniae NDM are described, as infectious or colonizing agents, in critically ill patients, mostly with neurosurgical pathology, of Hospital Nacional Dos de Mayo in Lima - Peru. The patients in the series described below represent the first reports of Klebsiella pneumoniae NDM in Peru.
La emergencia de enterobacterias productoras de carbapenemasas de tipo Nueva Delhi Metalo beta-lactamasas (NDM), representan, hoy en día, un verdadero problema de salud pública mundial. La presencia de este mecanismo de resistencia limita o anula las opciones terapéuticas para combatir a estas bacterias. En Latinoamérica, las cifras son cada vez más elevadas, pues se reportan en Guatemala, Colombia, Chile, Argentina, entre otros. Perú no ha descrito, hasta la fecha, la presencia de este patrón de resistencia; sin embargo, desde hace varios años se presume de su existencia. Se describen nueve casos de Klebsiella pneumoniae NDM, como agentes infecciosos o colonizantes, en pacientes críticamente enfermos, en su mayoría con patología neuroquirúrgica, del Hospital Nacional Dos de Mayo, en Lima - Perú. Los pacientes de la serie descrita a continuación, representan los primeros reportes de Klebsiella pneumoniae NDM en el Perú.
Subject(s)
Bacterial Proteins/biosynthesis , Klebsiella pneumoniae/classification , Klebsiella pneumoniae/enzymology , beta-Lactamases/biosynthesis , Adult , Aged , Aged, 80 and over , Female , Hospitals , Humans , Male , Microbial Sensitivity Tests , Middle Aged , PeruABSTRACT
RESUMEN La emergencia de enterobacterias productoras de carbapenemasas de tipo Nueva Delhi Metalo beta-lactamasas (NDM), representan, hoy en día, un verdadero problema de salud pública mundial. La presencia de este mecanismo de resistencia limita o anula las opciones terapéuticas para combatir a estas bacterias. En Latinoamérica, las cifras son cada vez más elevadas, pues se reportan en Guatemala, Colombia, Chile, Argentina, entre otros. Perú no ha descrito, hasta la fecha, la presencia de este patrón de resistencia; sin embargo, desde hace varios años se presume de su existencia. Se describen nueve casos de Klebsiella pneumoniae NDM, como agentes infecciosos o colonizantes, en pacientes críticamente enfermos, en su mayoría con patología neuroquirúrgica, del Hospital Nacional Dos de Mayo, en Lima - Perú. Los pacientes de la serie descrita a continuación, representan los primeros reportes de Klebsiella pneumoniae NDM en el Perú.
ABSTRACT The emergence of Enterobacteria producing carbapenemases of type New Delhi Metalo beta-lactamases (NDM), >represent, today, a real problem of world public health. The presence of this resistance mechanism limits or nullifies the therapeutic options to combat these bacteria. In Latin America, the figures are getting higher, as they are reported in Guatemala, Colombia, Chile, Argentina, among others. Peru has not, to date, described the presence of this resistance pattern; however for several years it has been presumed to exist. Nine cases of Klebsiella pneumoniae NDM are described, as infectious or colonizing agents, in critically ill patients, mostly with neurosurgical pathology, of Hospital Nacional Dos de Mayo in Lima - Peru. The patients in the series described below represent the first reports of Klebsiella pneumoniae NDM in Peru.
Subject(s)
Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Bacterial Proteins/biosynthesis , beta-Lactamases/biosynthesis , Klebsiella pneumoniae/classification , Klebsiella pneumoniae/enzymology , Peru , Microbial Sensitivity Tests , HospitalsABSTRACT
Solamente durante el presente año, en el mundo, cinco millones de personas se infectaron por el VIH y tres millones fallecen por esta causa.
Subject(s)
Humans , HIV Infections , Acquired Immunodeficiency SyndromeABSTRACT
Los procedimientos clásicos de aislamientos e identificación del agente etiológico de una enfermedad infecciosa seguirá vigentes, especialmente en nuestro medio, más allá del año 2000. El aislamiento del agente microbiano facilita ampliar su estudio, lo que incluye pruebas de susceptibilidad antimicrobiana, detección de toxinas, etc., que son no sólo de gran utilidad inmediata para el paciente sino también útil para la vigilancia epidemiológica de los microorganismos en una población y tiempo determinados
Subject(s)
Humans , Diagnosis , Microbiology , Communicable DiseasesABSTRACT
Este estudio de revisión bibliográfico sobre el género mycobacterium, puntualiza avances en la identificación en los aspectos básicos del comportamiento microbiológico, epidemiológico y las características clínico-patológicas principalmente de las especies de mycobacterias potencialmente patógenas de interés médico.
