ABSTRACT
OBJECTIVE: Malaria parasites invade, grow and multiply inside erythrocytes and obtain nourishment from haemoglobin. Then, the released haem group is oxidized to haematin and inert dimeric haemozoin bio-crystals form, which provides the parasite a unique way to avoid the toxicity associated with the haem group. Therefore, antimalarial drugs are designed to inhibit dimer formation; however, recent electrochemical studies indicate that an inert dimer also promotes a toxic oxidizing environment. Therefore, this work explores drug reactivity in the presence of monomers and dimers to evaluate their contribution to redox activity. MATERIALS AND METHODS: Three medicines mixed with haemozoin or ß-haemozoin in carbon paste electrodes were tested using cyclic voltammetry. RESULTS: The data indicated again that the substances modify the natural redox state of haemozoin and ß-haemozoin. This effect could be attributed to the natural oxidation potential of the drugs. In addition, it was found that the oxidation potential decreased through quinine, lumefantrine and artemether with the same tendency in the presence of haemozoin but with less current density. Additionally, it was observed that the oxidation response between the monomer haemozoin and antimalarial drugs is carried out at more negative potentials. CONCLUSIONS: Together, the total results indicate that antimalarials per se can contribute to oxidation processes and that in combination with monomeric or dimeric haemozoin can increase or decrease the oxidizing power of the haemozoin forms. The various oxidizing environments suggest that the cell membranes can also be damaged by the unique presence of the antimalarial.
Subject(s)
Antimalarials/chemistry , Artemether/chemistry , Hemoglobins/chemistry , Lumefantrine/chemistry , Quinine/chemistry , Animals , Electrodes , Hemiptera/chemistry , Humans , Oxidation-Reduction , Particle Size , Surface PropertiesABSTRACT
Los quistes aracnoideos son lesiones benignas, de origen congénito, formadas por una membrana aracnoidea, que contienen líquido cefalorraquídeo en su interior. Presentamos el caso de un niño de cinco años con una asimetría craneal con abombamiento frontoparietotemporal derecho. Refería vómitos ocasionales de un año de evolución y cefalea que no le despertaba por la noche desde hacía dos años, acompañada algunas veces de sonofobia y fotofobia. En las pruebas de imagen se visualizaba un gran quiste aracnoideo en la fosa craneal media derecha con desplazamiento de la línea media y colapso de las astas ventriculares adyacentes. Dado el tamaño del quiste y la clínica, se decidió tratamiento con cistocisternostomía endoscópica comunicando el quiste aracnoideo con las cisternas basales (AU)
Arachnoid cysts are benign, congenital malformations formed by an arachnoid membrane containing cerebrospinal fluid inside. We report the case of a 5 year old child with cranial asymmetry with right fronto-parieto-temporal bulging. Occasional vomiting a year of evolution and sometimes headache are refered, which did not wake him at night, accompanied by sonophobia and photophobia for two years. The imaging displays large arachnoid cyst in right middle cranial fossa with midline shift and collapse of adjacent ventricular horns. Because of the size of the cyst and the clinic, endoscopic treatment was selected, communicating arachnoid cyst and basal cisterns (AU)
Subject(s)
Humans , Male , Child , Brain Neoplasms/surgery , Brain Neoplasms , Medulloblastoma/complications , Medulloblastoma/surgery , Medulloblastoma , Diagnosis, Differential , Tomography, Emission-Computed/methods , Neurosurgery/methods , Neurosurgery/trends , Endoscopy/methods , EndoscopyABSTRACT
El hematocolpos constituye una patología poco prevalente en nuestro medio, secundaria a alteraciones en la génesis del aparato genitourinario femenino, entre las cuales el himen imperforado es la malformación congénita más frecuente. La sintomatología suele ser variable e inespecífica, y el dolor abdominal es la forma de presentación clínica más frecuente. En este artículo se exponen dos casos clínicos de adolescentes afectas de esta patología. Ambas presentaron abdominalgia y síntomas miccionales. La realización de una historia clínica detallada junto con la inspección de los genitales, así como la visualización en la ecografía abdominal de una colección sanguínea localizada en la vagina, fueron fundamentales para llegar al diagnóstico. En este artículo se pretende destacar la importancia de la anamnesis y la exploración genital ante una sintomatología tan inespecífica como son el dolor abdominal y la clínica miccional, ya que puede orientarnos al diagnóstico de forma sencilla, evitando pruebas innecesarias, medidas terapéuticas erróneas y aparición de complicaciones (AU)
Hematocolpos constitutes an unusual pathology in our environment, secondary to alterations in the genesis of female genitourinary tract, being the imperforate hymen the most common congenital malformation. The symptomatology is usually variable and nonspecific with abdominal pain as the most frequent clinical presentation. In this paper we present the description of two cases of teenagers affected by this disease. Both presented abdominal pain and urinary symptoms. Besides a detailed medical history along with the inspection of the genitalia as well as the visualization in the abdominal echography of a blood collection located in the vagina, were fundamental in order to make a diagnosis. Throughout this article we intend to emphasize the relevance of the medical history and genital examination before symptoms as nonspecific as abdominal pain and urinary symptoms because of it can help us to guide the diagnosis in an easy way avoiding unnecessary tests, erroneous therapeutic measures and appearance of complications (AU)
