Chitosan-coated manganese ferrite nanoparticles enhanced Rhodotorula toruloides carotenoid production.

The present study aims to analyze the interaction between Rhodotorula toruloides and magnetic nanoparticles and evaluate their effect on carotenoid production. The manganese ferrite nanoparticles were synthesized without chitosan (MnFe2O4) and chitosan coating (MnFe2O4-CS) by the co-precipitation method assisted by hydrothermal treatment. XRD (X-ray diffraction), Magnetometry, Dynamic Light Scattering (DLS) and FTIR (Fourier-Transform Infrared Spectroscopy), are used to characterize the magnetic nanoparticles. The crystallite size of MnFe2O4 was 16 nm for MnFe2O4 and 20 nm for MnFe2O4-CS. The magnetic saturation of MnFe2O4-CS was lower (39.6 ± 0.6 emu/g) than the same MnFe2O4 nanoparticles (42.7 ± 0.3 emu/g), which was attributed to the chitosan fraction presence. The MnFe2O4-CS FTIR spectra revealed the presence of the characteristic chitosan bands. DLS demonstrated that the average hydrodynamic diameters were 344 nm for MnFe2O4 and 167 nm for MnFe2O4-CS. A kinetic study of cell immobilization performed with their precipitation with a magnet demonstrated that interaction between magnetic nanoparticles and R. toruloides was characterized by an equilibrium time of 2 h. The adsorption isotherm models (Langmuir and Freundlich) were fitted to the experimental values. The trypan blue assay was used for cell viability assessment. The carotenoid production increased to 256.2 ± 6.1 µg/g dry mass at 2.0 mg/mL MnFe2O4-CS. The use of MnFe2O4-CS to stimulate carotenoid yeast production and the magnetic separation of biomass are promising nanobiotechnological alternatives. Magnetic cell immobilization is a perspective technique for obtaining cell metabolites.

ß-Carotene production from sugarcane molasses by a newly isolated Rhodotorula toruloides L/24-26-1.

Production of carotenoids by yeast fermentation is an advantaged technology due to its easy scaling and safety. Nevertheless, carotenoid production needs an economic culture medium and other efficient yeast stains. The study aims to isolate and identify a yeast strain capable of producing carotenoids using a cost-effective substrate. A new strain was identified as Rhodotorula toruloides L/24-26-1, which can produce carotenoids at different pretreated and unpretreated sugarcane molasses concentrations (40 and 80 g/L). The highest biomass concentration (18.6 ± 0.6 g/L) was reached in the culture using 80 g/L of hydrolyzed molasses. On the other hand, the carotenoid accumulation reached the maximum value using pretreated molasses at 40 g/L (715.4 ± 15.1 µg/g d.w). In this case, the ß-carotene was 1.5 times higher than that on the control medium. The yeast growth in molasses was not correlated with carotenoid production. The most outstanding production of The DPPH, ABTS, and FRAP tests demonstrated the antioxidant activity of the obtained carotenogenic extracts. This research demonstrated the R. toruloides L/24-26-1 strain biotechnological potential for carotenoid compounds. The yeast produces carotenoids with antioxidant activity in an inexpensive medium, such as sulfuric acid pretreated and unpretreated molasses.

Recovery and purification of Aspergillus niger phytase from crude extract using AOT / isooctane reversed micelles.

This work describes the successful extraction of Aspergillus niger phytase from a crude extract (CE) obtained from solid-state fermentation by reversed micelle system using anionic surfactant sodium bis (2-ethylhexyl) sulfosuccinate (AOT) in isooctane achieved in two simple steps: forward and backward extractions. The effects of potassium chloride (KCl) concentration, pH of the aqueous solution, and AOT concentration that affect the system were examined. The best result for the forward extraction was obtained with the CE solution at pH 4.0, 50 mM KCl, and 100 mM AOT, while for the backward extraction the best result was achieved with a stripping aqueous solution at pH 5.5 containing 200 mM KCl, achieving a purification factor of 4.03, 1.15 times higher than that reported for the conventional purification process. Phytase purity was demonstrated by SDS-PAGE (89 kDa) and its activity by zymogram, confirming the efficiency of the process with low time consumption (∼40 min).

Purification and biochemical characterization of an Aspergillus niger phytase produced by solid-state fermentation using triticale residues as substrate.

In this study, an extracellular phytase produced by Aspergillus niger 7A-1, was biochemically characterized for possible industrial application. The enzyme was purified from a crude extract obtained by solid-state fermentation (SSF) of triticale waste. The extract was obtained by microfiltration, ultrafiltration (300, 100 and 30 kDa) and DEAE-Sepharose column chromatography. The molecular weight of the purified enzyme was estimated to be 89 kDa by SDS-PAGE. The purified enzyme was most active at pH 5.3 and 56 °C, and retained 50% activity over a wide pH range of 4 to 7. The enzymatic thermostability assay showed that the enzyme retained more than 70% activity at 80 °C for 60 s, 40% activity for 120 s and 9% after 300 s. The phytase showed broad substrate specificity, a Km value of 220 µM and Vmax of 25 µM/min. The purified phytase retained 50% of its activity with phosphorylated compounds such as phenyl phosphate, 1-Naphthyl phosphate, 2-Naphthyl phosphate, p-Nitrophenyl phosphate and Glycerol-2-phosphate. The inhibition of phytase activity by metal ions was observed to be drastically inhibited (50%) by Ca++ and was slightly inhibited (10%) by Ni++, K+, and Na+, at 10 and 20 mM concentrations. A positive effect was obtained with Mg++, Mn++, Cu++, Cd++ and Ba++ at 25 and 35% with stimulatory effect on the phytase activity.

Improvement of L(+)-lactic acid production from cassava wastewater by Lactobacillus rhamnosus B 103.

BACKGROUND: L(+)-Lactic acid is used in the pharmaceutical, textile and food industries as well as in the synthesis of biodegradable plastics. The aim of this study was to investigate the effects of different medium components added in cassava wastewater for the production of L(+)-lactic acid by Lactobacillus rhamnosus B 103. RESULTS: The use of cassava wastewater (50 g L(-1) of reducing sugar) with Tween 80 and corn steep liquor, at concentrations (v/v) of 1.27 mL L(-1) and 65.4 mL L(-1) respectively led to a lactic acid concentration of 41.65 g L(-1) after 48 h of fermentation. The maximum lactic acid concentration produced in the reactor after 36 h of fermentation was 39.00 g L(-1) using the same medium, but the pH was controlled by addition of 10 mol L(-1) NaOH. CONCLUSION: The use of cassava wastewater for cultivation of L. rhamnosus is feasible, with a considerable production of lactic acid. Furthermore, it is an innovative proposal, as no references were found in the scientific literature on the use of this substrate for lactic acid production.

In vitro killing action of auranofin on Taenia crassiceps metacestode (cysticerci) and inactivation of thioredoxin-glutathione reductase (TGR).

Control of cellular redox homeostasis is a central issue for all living organisms. Glutathione and thioredoxin enzymatic redox systems are the usual mean used to achieve such a control. However, parasitic platyhelminths studied to date possess a nicotinamide adenine dinucleotide phosphate-dependent thioredoxin-glutathione reductase (TGR) as the sole redox control system. Thus, TGR is considered as a potential therapeutic target of parasitic platyhelminths, and based on this assumption, the gold compound auranofin is a potent inhibitor of TGR. The aim of this research was to investigate the effect of auranofin on metacestode (cysticerci) of Taenia crassiceps in culture. Accordingly, the time course for viability and respiration of cysticerci in culture was evaluated in the presence of this compound. After 4 h at 10 microM auranofin, 90% of cysticerci were alive, but respiration activity had declined by 50%. After 12 h, neither survivors nor respiration was detected; a LD(50) for auranofin of 3.8 microM was calculated. Interestingly, crude extracts of cysticerci pretreated with 3 microM auranofin nearly nil TGR activity (IC(50) = 0.6 microM). Zymography for TGR in polyacrylamide gel electrophoresis was conducted because the previously mentioned extracts clearly showed a dose-response inactivation of TGR toward auranofin. The killing of cysticerci by this gold compound is most likely related with TGR inactivation. Therefore, further research on the suitability of auranofin as a therapeutic tool in the treatment of cysticercosis in animals and humans is sustained.

An interphase fluorescence in situ hybridisation assay for the detection of 3q26.2/EVI1 rearrangements in myeloid malignancies.

Chromosome rearrangements involving band 3q26.2 are associated with myeloid malignancies, aberrant expression of the human ecotropic virus integration site-1 (EVI1) gene, an unfavourable prognosis and an aggressive clinical course. The 3q26.2 rearrangements are characteristically heterogeneous and typically difficult to detect in poor quality metaphases. To develop a dual-colour fluorescence in situ hybridisation (FISH) assay for the detection of 3q26.2/EVI1 aberrations, a series of 10 BAC clones corresponding to the EVI1 gene region were systematically evaluated and narrowed down to two probe sets; one probe set encompassed the EVI1 gene extending centromeric, while the second probe set covered the EVI1 gene and extends telomeric. Both probe sets were evaluated on 35 patient samples with cytogenetically defined 3q26.2 rearrangements collected at various treatment time points, the inv(3)(q21q26.2) Kasumi-4 cell line, and 10 known negative samples. The two-probe set strategy identified all samples, despite the vast breakpoint heterogeneity observed. In samples from acute myeloid leukaemia and myelodysplastic syndrome cases, the majority of inversion breakpoints were 3' to EVI1 whereas 3q26.2 translocation breakpoints frequently mapped 5' to EVI1. However, two 3q26.2 translocation samples had breakpoints 3' to EVI1. Most inv(3q) chronic myeloid leukaemia samples showed breakpoints within the EVI1 gene. This study demonstrated that, despite the extensive breakpoint heterogeneity observed with 3q26.2 aberrations, this FISH strategy is effective for the detection of 3q26.2 abnormalities in myeloid malignancies.

Differential O-glycosylation in cortical and medullary thymocytes.

Differentiation of T lymphocytes is characterized by variable expression of CD8/CD4 co-receptor molecules and changes in the glycosylation pattern. In this work, O-glycosylation was analyzed in microsomes from murine thymocytes purified with the PNA and Amaranthus leucocarpus (ALL) lectins, specific for the T antigen (Gal beta1,3GalNAc1,0 Ser/Thr) in cortical and medullary thymocytes, respectively. Three peptides were used as acceptors for UDP-N-acetylgalactosamine: polypeptide N-acetylgalactosaminyl-transferase (GalNAc transferase); the peptide motif TTSAPTTS was the best glycosylated one. Cortical ALL-PNA+ thymocytes showed two-fold higher GalNAc transferase activity than ALL+PNA- thymocytes; however, capillary electrophoresis showed a higher proportion of di- versus mono-glycosylated peptides for ALL+PNA- than for ALL-PNA+. We compared the GalNAc transferase activity of thymocytes from dexamethasone-treated mice versus control mice. GalNAc transferase activity was six-fold higher in thymocytes from control mice than from dexamethasone-treated mice; the rate of di-glycosylated peptides for dexamethosone-resistant ALL+ was two-fold higher than for ALL- thymocytes. Our results confirm an upregulated biosynthesis of O-glycosidically linked glycans on T cell surface glycoproteins, and suggest that the modification of GalNAc transferase activity plays a relevant role during the maturation process of thymic cells.

Consistencia interna y estructura factorial del Cuestionario de Influencia de los Modelos Estéticos Corporales (CIMEC), en población mexicana / Internal consistency and factorial structure of the questionaire of Socioculatural Influences on the Aesthetic body shape model in the Mexican population

Los modelos socioculturales generalmente brindan un importante apoyo teórico para explicar los altos niveles-que prevalecen en la mayoría de los países-de trastornos de la imagen corporal y el incremento de trastornos alimentarios entre las mujeres. Estos modelos sostienen que el actual estándar de belleza enfatiza desmesuradamente la conveniencia de la delgadez. No obstante que se conoce la importancia del factor cultural en el desarrollo y mantenimiento de los trastornos de la imagen corporal, las investigaciones empiricas han tenido dificultades por carecer de un instrumento diseñado para evaluar dicha influencia.El Cuestionario de Influencias del Modelo Estético Corporal (CIMEC) (21) fue diseñado para intentar medir la influencia de los agentes y situaciones que transmiten el modelo estético actual. La validez se llevó a cabo en 118 jóvenes españolas: 59 anoréxicas y 59 controles igualadas en cuanto a edad y clase social. El cuestionario mostró una adecuada consistencia interna, así como una apropiada sensibilidad y especificidad, por lo que podría servir como un instrumento de criba o tamizaje debido a su relación con la anorexia nerviosa y las influencias socioculturales.El presente trabajo tuvo como objetivo evaluar el estatus psicométrico de la escala CIMEC en la población mexicana. Este cuestionario se aplicó a una población de 1001 mujeres que estudiaban el bachillerato y la carrera universitaria en instituciones públicas y privadas, con un rango de edad de 14 a 33 años.El coeficiente de validez alpha fue 0.94, lo que confirma que el cuestionario CIMEC tiene una satisfactoria consistencia interna. El análisis factorial y la rotación varimax proporcionaron seis factores. Posteriormente, a partir de un análisis confirmatorio, éstos fueron agrupados en cuatro factores que explicaron 45.3 por ciento de la varianza total.El factor 1 mostró ser significativamente el más importante (a = 0.92). Está compuesto por 14 preguntas que pueden ser identificadas como Influencia de la Publicidad. El factor 2 contiene 10 preguntas que evalúan la ansiedad ante situaciones que cuestionan la autopercepción corporal, y fue llamado Malestar por la Imagen Corporal y Conductas para Reducir de Peso (a = 0.86). El factor 3 contiene seis preguntas relacionadas con la Influencia de los Modelos Sociales (a = 0.75).

La utilización de esteroides y psicofármacos en pacientes con retinosis pigmentaria / The use of steroids and psychotropic drugs in patients with retinitis pigmentosa

Se realiza un estudio de 800 pacientes con el diagnóstico de retinosis pigmentaria tratados en la Clínica Cira García en el período de enero 1991 enero 1992. Se revisaron las encuestas e historias clínicas realizadas al ingreso con el objetivo de conocer la administración de tratamientos anteriores con esteroides, psicofármacos y automedicación. Se obtuvo un predominio de la terapéutica con derivados de las benzodiazepinas y la clorpromacina en un 46 % y 31 % respectivamente, seguidos del uso de esteroides en un 23 %. Más del 90 % de estos enfermos se encontraban en el estadio final de la enfermedad

Algunas actividades de promoción de salud en los trabajadores de la salud

Con el propósito de conocer en que medida los trabajadores de la salud posen un grupo de condiciones personales que les permitan ser abanderados en el trabajo de promocón de salud entre la población. Se realizó un estudio exploratorio mediante la aplicación de un cuestionario sencillo que solicitaba información sobre los hábitos y conductas. Que en torno a factores de incidencia en la salud, practican un grupo de trabajadores del sector. Dicho cuestionario se aplicó en 3 hospitales de diferentes provincias del país a un total de 132 trabajadores y a partir de las respuestas ofrecidas por ellos, se obtuvo una interesante y valiosa información relacionada con el tema en cuestión (AU)

Mortalidad por diabetes mellitus en Cuba: estudio histórico / Diabetes ellitus mortality in Cuba: a historical study

Se realiza una breve reseña sobre la importancia de la diabetes mellitus como problema de salud actual y la importancia del conocimiento de los cambios históricos en lo relativo a la mortalidad por diabetes en nuestra población como indicador, antes de la iniciación de un programa con vistas a que dichas tasas sean semejantes a la de la población general. Se utilizó toda la información existente en el Deparatamento Nacional de Estadísticas del MINSAP y datos del Comité Estatal de Estadística sobre población en el período comprendido entre 1910 y 1983. Se señalan las tasas de mortalidad según sexo, grupos de edades y provincias. Se concluye que nuestra tasa de mortalidad es intermedia entre las que informan los países altamente desarrollados y otros países subdesarrollados de América Latina

Mortalidad por diabetes mellitus en Cuba: estudio histórico / Diabetes mellitus mortality in Cuba: a historical study

Se realiza una breve reseña sobre la importancia de la diabetes mellitus como problema de salud actual y la importancia del conocimiento de los cambios históricos en lo relativo a la mortalidad por diabetes en nuestra población como indicador, antes de la iniciación de un programa con vistas a que dichas tasas sean semejantes a la de la población general. Se utilizó toda la información existente en el Deparatamento Nacional de Estadísticas del MINSAP y datos del Comité Estatal de Estadística sobre población en el período comprendido entre 1910 y 1983. Se señalan las tasas de mortalidad según sexo, grupos de edades y provincias. Se concluye que nuestra tasa de mortalidad es intermedia entre las que informan los países altamente desarrollados y otros países subdesarrollados de América Latina

Mortalidad por diabetes mellitus en Cuba: estudio histórico / Diabetes mellitus mortality in Cuba: a historical study

Se realiza una breve reseña sobre la importancia de la diabetes mellitus como problema de salud actual y la importancia del conocimiento de los cambios históricos en lo relativo a la mortalidad por diabetes en nuestra población como indicador, antes de la iniciación de un programa con vistas a que dichas tasas sean semejantes a la de la población general. Se utilizó toda la información existente en el Deparatamento Nacional de Estadísticas del MINSAP y datos del Comité Estatal de Estadística sobre población en el período comprendido entre 1910 y 1983. Se señalan las tasas de mortalidad según sexo, grupos de edades y provincias. Se concluye que nuestra tasa de mortalidad es intermedia entre las que informan los países altamente desarrollados y otros países subdesarrollados de América Latina