Capacidad antioxidante y mecanismo de acción de pigmentos en organismos marinos / Antioxidant capacity and mechanism of action of pigments in marine organisms

Resumen Los organismos marinos poseen maravillosos colores que los hacen muy atractivos. Las características únicas de los compuestos sintetizados por especies de origen marino van más allá de su apariencia. Los pigmentos responsables de esos colores son capaces también de generar diversas actividades biológicas, como la capacidad antioxidante, la cual puede ocurrir a través de diversos mecanismos. Esto ha propiciado un aumento de su investigación, debido a su amplia aplicación en la biotecnología, farmacéutica, cosmética y alimentación de organismos vivos, expandiendo los estudios tanto in vitro como en ensayos in vivo. El objetivo de este trabajo fue compilar y describir diversos estudios recientes, enfocados en demostrar y elucidar los mecanismos de acción de los diferentes compuestos bioquímicos con actividad antioxidante, provenientes de algunos organismos marinos. Para ello, se utilizaron las bases de datos Scopus®, Web of Science™ y Microsoft Academic. Los pigmentos provenientes de organismos marinos representan una alternativa promisoria frente a los antioxidantes y aditivos sintéticos utilizados en la actualidad. El establecimiento y comprensión de los mecanismos de acción de los componentes pigmentados bioactivos, aislados de los organismos marinos, permitirá determinar con mayor precisión su posible aplicación en la industria.

Abstract Marine organisms have wonderful colors that make them very attractive. The unique characteristics of the compounds synthesized by species of marine origin go beyond their appearance. The pigments responsible for these colors are also capable of exerting biological activities, including the antioxidant capacity, which can be performed by different mechanisms. This has led to an increase in research attention due to their potential application in the pharmaceutical, cosmetics and food industries, and has expanded from in vitro studies to in vivo tests. The objective of this review is to compile and describe the studies aimed at establishing and elucidating the mechanisms of action of different biochemical compounds with antioxidant activities from marine species. In order to achieve that objective, the Scopus®, Web of Science™ and Microsoft Academic databases were used. Marine pigments represent a promising alternative to the antioxidants and synthetic additives used today. By establishing and understanding the mechanisms of action of the bioactive pigmented compounds isolated from marine organisms, it is possible to determine with greater precision their possible application in the industry.

Evaluation of Dosidicus gigas Skin Extract as An Antioxidant and Preservative in Tuna Pâté.

A strategy for food preservation, based on a methanol-HCl squid skin extract (Dosidicus gigas) (JSSE), was evaluated at two concentrations in yellowfin tuna fish pâtés, which were stored at 4 and 8 °C for 20 day. The JSSE was characterized by determining its antioxidant and mutagenic activities. A yellowfin tuna pâté was elaborated, with and without the addition of the JSSE. An affective sensory analysis was performed to establish consumers' preferences. During a 20-day storage period, the water activity (aw), pH, color difference (ΔE*ab), microbiological analysis, lipid oxidation and sensory quality attributes were evaluated, and the results were compared with the results of the butylated hydroxyanisole (BHA) and control treatments. The JSSE showed antioxidant activity against the 2,2-diphenyl-1-picrylhydrazyl (DPPH●+) and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS●) radicals and did not induce mutation, according to the Ames' Salmonella test, nor chromosomal abnormalities, according to the onion root-tip cell assay. The consumer analysis demonstrated a higher preference for the pâté with the added JSSE in seven out of the eight evaluated attributes. During storage, the JSSE neither had an impact on aw nor pH, maintained lower ΔE*ab values, inhibited the microbial activity and lipid oxidation (unlike the control pâté), and preserved the sensory quality attributes, unlike the BHA and control treatments. This study showed that the JSSE has biologically active pigments that can act as antioxidants and antimicrobials in yellowfin tuna fish pâtés.

Diagnosis of acute leukemia in cerebrospinal fluid (CSF-acute leukemia).

Cerebrospinal fluid-acute leukemia (CSF-acute leukemia) is a frequent and serious complication in patients with acute leukemia. One of the major problems of this complication is the diagnosis process itself. CSF cytology is currently considered the gold standard for establishing the diagnosis, a technique which presents various processing limitations, seriously impacting the predictive values. In the last 11 years, studies of CSF flow cytometry analysis done in patients with acute leukemia have demonstrated superiority in comparison with CSF cytology. Although comparative studies between these two techniques have been reported since 2001, no new consensus or formal changes to the gold standard have been established for the CSF acute leukemia diagnosis. The evidence suggests that positive flow cytometry cases, considered as indeterminate cases, will behave like disease in the central nervous system (CNS). Nevertheless, we think there are some variables and considerations that must be first evaluated under research protocols before CNS relapse can be established with only one positive flow cytometry analysis in the setting of indeterminate CSF samples. This paper proposes a diagnostic algorithm and complementary strategies.

Neurocysticercosis: radiologic-pathologic correlation.

Neurocysticercosis is a neurologic parasitic disease caused by the encysted larva of the tapeworm Taenia solium and is the most important parasitic disease of the human central nervous system. It is the most common cause of acquired epilepsy in endemic settings and constitutes a public health challenge for most of the developing world. Nowadays, however, as a result of globalization, neurocysticercosis is being seen more frequently in developed countries as well. Neurocysticercosis is acquired through fecal-oral contamination, and the disease course is complex, with two intermediate hosts (ie, pigs and humans) and a definitive host (humans). Traditionally, it has been classified into active and nonactive forms according to disease location. Radiologists must be aware of its imaging appearance, which is quite variable, as is the differential diagnosis. Imaging findings depend on several factors, including the stage of the life cycle of T solium at presentation; the number and location (ie, subarachnoid, cisternal, or intraventricular) of parasites; and associated complications such as vascular involvement (ie, arteritis with or without infarction), inflammatory response (ie, edema, gliosis, or arachnoiditis), and, in ventricular forms, degree of obstruction. Thus, the diagnostic approach, management, and prognosis for neurocysticercosis differ widely depending on the type of infection.

Predictive factors for intracerebral hemorrhage in patients with cavernous angiomas.

OBJECTIVES: Prediction of intracerebral hemorrhage (ICH) in patients with cavernous angiomas is not totally elucidated. The aims of our study were to determine the rate of cerebral hemorrhage, its associated factors, and the clinical outcome in patients with cavernous angiomas in a Hispanic population. METHODS: We studied 133 patients with cavernous angiomas. The patients were classified into two groups depending on whether they presented an ICH. A comparative analysis of demographics and clinical data, neuroimaging characteristics, and prognosis was carried out in patients with and without hemorrhage. The hemorrhage rate (expressed as the percentage per patient per year) was also estimated. RESULTS: Seventy-eight patients (59%) had hemorrhage. Non-lobar location of angiomas was associated with hemorrhage [OR 4.82 (CI 95% 2.17-10.73; p=<0.001)]. In contrast, factors associated with a decreased risk of hemorrhage were a family history of epilepsy [OR 0.30 (CI 95% 0.10-0.79; p=0.016)] and lobar location of the angiomas [OR 0.21 (CI 95% 0.09-0.46; p=<0.001)]. The hemorrhagic rate of 1.71% per patient per year was influenced by the location. It was only 1.22% per patient per year in lobar angiomas and 2.33, 2.39, and 2.82% per patient per year for brainstem, cerebellum, and deep hemispheric angiomas, respectively. CONCLUSIONS: The non-lobar location of cavernous angiomas gives a higher risk of hemorrhage in our Mexican mestizo population, without the hemorrhage being related to either age or sex.

Prospective study of single and multiple lacunar infarcts using magnetic resonance imaging: risk factors, recurrence, and outcome in 175 consecutive cases.

BACKGROUND AND PURPOSE: We investigated whether lacunar infarct (LI) patients with >1 lacune have different vascular risk factors, a different prognosis, and poorer functional outcome than those with a single lacune. METHODS: The study included 175 first-ever LI patients. The group was divided according to the presence of multiple (n=136) or single (n=39) LI. The association of single or multiple LI with the principal vascular risk factors, leukoaraiosis, outcome, and recurrence was investigated with logistic regression models that included age, sex, and cardiac disease. RESULTS: No significant differences were found between single and multiple LI with respect to age, hypertension, hyperlipidemia, smoking, and heavy alcohol drinking. Diabetes mellitus (odds ratio [OR], 2.43; 95% CI, 1.09 to 5.4), high levels of hematocrit (>0.47) (OR, 1.09; 95% CI, 1.04 to 1.21), and leukoaraiosis (OR, 3.58; 95% CI, 1.77 to 7.51) were significantly related to multiple but not to single LI. Stroke recurrence rate was 7.7% in patients with single LI and 24.3% in the multiple LI group (OR, 3.84; 95% CI, 1.1 to 13.3). During a median follow-up of 12 months (range, 6 to 156 months), 94% of the single LI patients and 77.2% of the multiple LI patients had favorable outcomes (Rankin Scale score 0 to 2) (OR, 5.4; 95% CI, 1.25 to 23.9). CONCLUSIONS: Diabetes mellitus, leukoaraiosis, and high levels of hematocrit are important risk factors in patients with >1 LI. The presence of multiple LI may be an important prognostic indicator not only for functional recovery but also for a higher rate of recurrence.