Reproducibilidad de la densidad vascular peripapilar, cabeza del nervio óptico y área macular por OCT-A de acuerdo con la severidad del glaucoma / Reproducibility of peripapillary, optic nerve head and macular vessel density by OCT-A according to glaucoma severity staging

Objetivo Evaluar la reproducibilidad de la densidad vascular (DV) peripapilar, cabeza del nervio óptico (ONH-PP) y área macular mediante angiografía por tomografía de coherencia óptica de dominio espectral (SD OCT-A) en pacientes con glaucoma y en sujetos sanos. Métodos Estudio transversal que evaluó 63 ojos de 63 sujetos, incluyendo 33 pacientes con glaucoma y 30 sujetos sanos. El glaucoma se clasificó en leve, moderado o avanzado. Dos exploraciones consecutivas fueron adquiridas por Spectralis Module OCT-A (Heidelberg, Alemania) y proporcionaron imágenes del complejo vascular superficial (SVC), del plexo vascular de la capa de fibra nerviosa (NFLVP) y del plexo vascular superficial (SVP); del complejo vascular profundo (DVC), del plexo capilar intermedio (ICP) y del plexo capilar profundo (DCP). La DV (%) fue calculada mediante AngioTool. Se calcularon los coeficientes de correlación intraclase (ICC) y los coeficientes de variación (CV). Resultados Respecto a la DV de ONH-PP, el mejor ICC lo presentó el glaucoma avanzado (0,86-0,96) y moderado (0,83-0,97) en comparación con el glaucoma leve (0,64-0,86). Para la DV macular, los resultados de ICC para las capas retinianas superficiales fueron mejores para el glaucoma leve (0,94-0,96), seguido por el glaucoma moderado (0,88-0,93) y por el avanzado (0,85-0,91), y para las capas retinianas más profundas el ICC fue más alto para el glaucoma moderado (0,95-0,96), seguido por el glaucoma avanzado (0,80-0,86) y por el leve (0,74-0,91). Los CV oscilaron entre el 2,2% y el 10,94%. Entre los sujetos sanos, los ICC para las mediciones de DV ONH-PP (0,91-0,99) y para las mediciones de la DV macular (0,93-0,97) fueron excelentes en todas las capas, con CV del 1,65% al 10,33% (AU)

Objective To assess the reproducibility of peripapillary, optic nerve head (ONH-PP) and macular vessel density (VD) by spectral domain optical coherence tomography angiography (SD OCT-A) in glaucoma patients and healthy subjects. Methods Cross-sectional study assessing 63 eyes of 63 subjects, including 33 glaucoma patients and 30 healthy subjects. Glaucoma was classified in mild, moderate, or advanced. Two consecutive scans were acquired by spectralis module OCT-A (Heidelberg, Germany), and provided images of the superficial vascular complex (SVC), nerve fiber layer vascular plexus (NFLVP), superficial vascular plexus (SVP), deep vascular complex (DVC), intermediate capillary plexus (ICP) and deep capillary plexus (DCP). VD (%) was calculated by AngioTool. Intraclass correlation coefficients (ICCs) and coefficients of variation (CV) were calculated. Results Among ONH-PP VD, better ICC presented advanced (0.86-0.96) and moderate glaucoma (0.83-0.97) compared with mild glaucoma (0.64-0.86). For the macular VD reproducibility, ICC results for superficial retinal layers were better for mild glaucoma (0.94-0.96) followed by moderated (0.88-0.93) and advanced glaucoma (0.85-0.91), and for deeper retinal layers ICC was better for moderate glaucoma (0,95-0,96) followed by advanced (0.80-0.86) and mild glaucoma (0.74-0.91). CVs ranged from 2.2%% to 10.94%. Among healthy subjects, ICCs for the ONH-PP VD measurements (0.91-0.99) and for the macular VD measurements (0.93-0.97) were excellent in all layers, with CVs from 1.65% to 10.33%. Conclusions SD OCT-A used to quantify macular and ONH-PP VD showed excellent and good reproducibility in most layers of the retina, both in healthy subjects and in glaucoma patients regardless of the severity of the disease (AU)

Reproducibility of peripapillary, optic nerve head and macular vessel density by OCT-A according to glaucoma severity staging.

OBJECTIVE: To assess the reproducibility of peripapillary, optic nerve head (PP-ONH) and macular vessel density (VD) by Spectral Domain optical coherence tomography angiography (SD OCT-A) in glaucoma patients and healthy subjects. METHODS: Cross-sectional study assessing 63 eyes of 63 subjects, including 33 glaucoma patients and 30 healthy subjects. Glaucoma was classified in mild, moderate, or advanced. Two consecutive scans were acquired by Spectralis Module OCT-A (Heidelberg, Germany), and provided images of the superficial vascular complex (SVC), nerve fiber layer vascular plexus (NFLVP), superficial vascular plexus (SVP); deep vascular complex (DVC), intermediate capillary plexus (ICP) and deep capillary plexus (DCP). VD (%) was calculated by AngioTool. Intraclass correlation coefficients (ICCs) and coefficients of variation (CV) were calculated. RESULTS: Among PP-ONH VD, better ICC presented advanced (ICC 0.86-0.96) and moderate glaucoma (ICC 0.83-0.97) compared with mild glaucoma (0.64-0.86). For the macular VD reproducibility, ICC results for superficial retinal layers were better for mild glaucoma (0.94-0.96) followed by moderated (0.88-0.93) and advanced glaucoma (0.85-0.91), and for deeper retinal layers ICC was better for moderate glaucoma (0.95-0.96) followed by advanced (0.80-0.86) and mild glaucoma (0.74-0.91). CVs ranged from 2.2% to 10.94%. Among healthy subjects, ICCs for the PP-ONH VD measurements (0.91-0.99) and for the macular VD measurements (0.93-0.97) were excellent in all layers, with CVs from 1.65% to 10.33%. CONCLUSIONS: SD OCT-A used to quantify macular and PP-ONH VD showed excellent and good reproducibility in most layers of the retina, both in healthy subjects and in glaucoma patients regardless of the severity of the disease.

Salud ocupacional en agricultura: necesidad de implementar programas ergonómicos en el Perú / Occupational health in agriculture: The need to implement ergonomic programs in Peru

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Chromatographic removal combined with heat, acid and chaotropic inactivation of four model viruses.

The virus removal of protein A affinity chromatography, inactivation capacity, acid pH and a combination of high temperature with a chaotropic agent was determined in this work. The model viruses studied were sendaivirus, human immunodeficency virus (HIV-IIIb), human poliovirus type-II, human herpesvirus I and canine parvovirus. The protein A affinity chromatography showed a maximum reduction factor of 8 logs in the case of viruses larger than 120 nm size, while for small viruses (18-30 nm) the maximum reduction factor was about 5 logs. Non viral inactivation was observed during the monoclonal antibody elution step. Low pH treatment showed a maximum inactivation factor of 7.1 logs for enveloped viruses. However, a weak inactivation factor (3.4 logs) was obtained for DNA nonenveloped viruses. The combination of high temperature with 3 M KSCN showed a high inactivation factor for all of the viruses studied. The total clearance factor was 23.1, 15.1, 13.6, 20.0 and 16.0 logs for sendaivirus, HIV-IIIb, human poliovirus type-II, human herpesvirus I and canine parvovirus, respectively.

[A chromatographic analysis of the Mycobacterium tuberculosis strains isolated from an outbreak in HIV patients in Cuba]. / Análisis cromatográfico de cepas de Mycobacterium tuberculosis aisladas de un brote en pacientes VIH en Cuba.

A group of strains of Mycobacterium tuberculosis isolated from an outbreak in HIV-infected patients was studied by chromatographic techniques. A group of strains of M. Tuberculosis from symptomatic respiratory patients (SR+ 14) and patterns strains from the laboratory collection were used as a reference aimed at making a qualitative comparison of the chromatographic patterns described by the strains isolated from patients. The chromatographic profiles of the strains isolated from patients (SR+) and fro HIV+ were obtained and compared by thin layer chromatography (TLC). Each of the present fatty acids was identified by using the gas chromatography technique (GC) coupled to mass spectrum analysis. All the studied strains were classified as Mycobacterium tuberculosis. According to the results attained, the usefulness of the chromatographic techniques as alternative techniques for the mycobacterial diagnosis is demonstrated.

Adsorption-desorption of recombinant hepatitis B surface antigen (r-HBsAg) from P. pastoris on a diatomaceous earth matrix: Optimization of parameters for purification.

Recombinant hepatitis B surface antigen (r-HBsAg) produced in yeast is adsorbed on a diatomaceous earth matrix for purification purposes. A pH dependence in the adsorption-elution behavior was found. The capacity of celite (Hyflo Super Cei) for adsorbing r-HBsAg increased with decreasing pH. Nonspecific proteins were also adsorbed, but a low pH dependence was found. Elution from the matrix was performed using a basic pH buffer, in which r-HBsAg is more specifically adsorbed/desorbed than contaminant proteins, permitting the purification of the r-HBsAg. A pH of 4.0 was used for adsorption and pH 8.2 was used for desorption. The described protocol allows a purification factor between three- and fivefold with respect to contaminant proteins and sixfold with respect to contaminant DNA. Finally, the adsorption step was successfully scaled-up for production purposes.

Niveles de producción de interferón alfa-2 recombinante por células de Saccharomyces cerevisiae libres e inmovilizadas / Production levels of recombinant alpha-2 interferon by free and immovibilized Saccharomyces cerevisiae cells

En este trabajo se emplean células de Saccharomyces cerevisiae, portando dos construcciones genéticas para la secreción de interferón *-2. Se estudian los cultivos de las células libres (en reactores convencionales) e inmovilizadas en alginato de sodio. Se alcanzan niveles de interferón *-2. Se estudian los cultivos de las células libres (en reactores convencionales) e inmovilizadas en alginato de sodio. Se alcanzan niveles de interferón *-2 extracelular de 4-8 X 10e6 UI/ml, y productividades de hasta 15 mg de interferón por litro de volumen útil de reactor y por hora cuando se emplea una concentración celular de 0,05 g de biomasa húmeda por mililitro de gel en la inmovilización

Niveles de producción de interferón alfa-2 recombinante por células de Saccharomyces cerevisiae libres e inmovilizadas / Production levels of recombinant alpha-2 interferon by free and immovibilized Saccharomyces cerevisiae cells

En este trabajo se emplean células de Saccharomyces cerevisiae, portando dos construcciones genéticas para la secreción de interferón *-2. Se estudian los cultivos de las células libres (en reactores convencionales) e inmovilizadas en alginato de sodio. Se alcanzan niveles de interferón *-2. Se estudian los cultivos de las células libres (en reactores convencionales) e inmovilizadas en alginato de sodio. Se alcanzan niveles de interferón *-2 extracelular de 4-8 X 10e6 UI/ml, y productividades de hasta 15 mg de interferón por litro de volumen útil de reactor y por hora cuando se emplea una concentración celular de 0,05 g de biomasa húmeda por mililitro de gel en la inmovilización (AU)

Expresión del gen de la quimosina en E. coli / Expression of the chymosin gene in E. coli

En este trabajo se describe la clonación y la expresión en E. coli del gen de la quimosina, enzima de importancia industrial para la producción de quesos. Los clones se identificaron analizando una genoteca de ADN complementario al ARN poli (A) proveniente del estómago de ternero, utilizando como sonda dos oligonucléotidos sintéticos. La región del gen, codificante a la proquimosina, fue expresada bajo el control del promotor triptófano. Se alcanzó una expresión equivalente al 10 % de la proteína total. La proteína fue detectada insoluble y formando cuerpos de inclusión. La enzima producida demostró tener propiedades semejantes a la natural.

Expresión del gen de la quimosina en E. coli / Expression of the chymosin gene in E. coli

En este trabajo se describe la clonación y la expresión en E. coli del gen de la quimosina, enzima de importancia industrial para la producción de quesos. Los clones se identificaron analizando una genoteca de ADN complementario al ARN poli (A) proveniente del estómago de ternero, utilizando como sonda dos oligonucléotidos sintéticos. La región del gen, codificante a la proquimosina, fue expresada bajo el control del promotor triptófano. Se alcanzó una expresión equivalente al 10

de la proteína total. La proteína fue detectada insoluble y formando cuerpos de inclusión. La enzima producida demostró tener propiedades semejantes a la natural.

Biologicals production by recombinant DNA technology in Cuba.

During 1981 we started an intensive programme for the development of biotechnology in Cuba. The first project was related to the production of leucocyte interferon and the cloning an expression of these genes in prokaryotic and yeast cells. These products are currently obtained in large amounts and their physical and chemical characterization are presented. The use of mammalian cells in culture for the production of recombinant proteins has also been carried out. The results obtained with the expression and amplification of the hepatitis B surface antigen (HBsAg) in CHO cells are discussed and compared with that obtained in yeast. The construction of a recombinant vaccinia virus carrying the HBsAg was also achieved. The specific transcripts were characterized and the Ab levels tested in animals. The results presented here indicate that the host system is a very important aspect to be taken into consideration and in some cases mammalian cells appear to be the best choice.

Altos niveles de expresión del gen del interferón *-2 humano bajo el control del promotor derecho del fago Lambda en E. coli / High expression levels of human *-2 interferón gene under the control of Lambda right promoter in E. coli

El gen del interferón *-2 humano (IFN-2) fue expresado en E. coli bajo el control del promotor derecho del bacteriófago Lambda (PR). La expresión de la actividad de IFN-2 en células que contenían este plásmido fue termoinducible. Se lograron niveles de expresión de hasta 5 x 108 UI/I

Altos niveles de expresión del gen del interferón *-2 humano bajo el control del promotor derecho del fago Lambda en E. coli / High expression levels of human *-2 interferón gene under the control of Lambda right promoter in E. coli

El gen del interferón *-2 humano (IFN-2) fue expresado en E. coli bajo el control del promotor derecho del bacteriófago Lambda (PR). La expresión de la actividad de IFN-2 en células que contenían este plásmido fue termoinducible. Se lograron niveles de expresión de hasta 5 x 108 UI/I