RESUMEN
Cationic antimicrobial peptides (AMPs) have attracted a great interest as novel class of antibiotics that might help in the treatment of infectious diseases caused by pathogenic bacteria. However, some AMPs with high antimicrobial activities are also highly hemolytic and subject to proteolytic degradation from human and bacterial proteases that limit their pharmaceutical uses. In this work a D-diastereomer of Pandinin 2, D-Pin2, was constructed to observe if it maintained antimicrobial activity in the same range as the parental one, but with the purpose of reducing its hemolytic activity to human erythrocytes and improving its ability to resist proteolytic cleavage. Although, the hydrophobic and secondary structure characteristics of L- and D-Pin2 were to some extent similar, an important reduction in D-Pin2 hemolytic activity (30-40 %) was achieved compared to that of L-Pin2 over human erythrocytes. Furthermore, D-Pin2 had an antimicrobial activity with a MIC value of 12.5 µM towards Staphylococcus aureus, Escherichia coli, Streptococcus agalactiae and two strains of Pseudomonas aeruginosa in agar diffusion assays, but it was half less potent than that of L-Pin2. Nevertheless, the antimicrobial activity of D-Pin2 was equally effective as that of L-Pin2 in microdilution assays. Yet, when D- and L-Pin2 were incubated with trypsin, elastase and whole human serum, only D-Pin2 kept its antimicrobial activity towards all bacteria, but in diluted human serum, L- and D-Pin2 maintained similar peptide stability. Finally, when L- and D-Pin2 were incubated with proteases from P. aeruginosa DFU3 culture, a clinical isolated strain, D-Pin2 kept its antibiotic activity while L-Pin2 was not effective.
Asunto(s)
Antibacterianos/química , Péptidos Catiónicos Antimicrobianos/química , Péptidos/química , Secuencia de Aminoácidos , Antibacterianos/farmacología , Péptidos Catiónicos Antimicrobianos/farmacología , Bacterias/efectos de los fármacos , Estabilidad de Enzimas , Eritrocitos/efectos de los fármacos , Hemólisis , Humanos , Datos de Secuencia Molecular , Elastasa Pancreática/química , Péptidos/farmacología , Conformación Proteica , Estabilidad Proteica , Estereoisomerismo , Tripsina/químicaRESUMEN
This communication reviews most of the important findings related to venom components isolated from scorpions and spiders, mainly by means of gene cloning and expression. Rather than revising results obtained by classical biochemical studies that report structure and function of venom components, here the emphasis is placed on cloning and identification of genes present in the venomous glands of these arachnids. Aspects related to cDNA library construction, specific or random ESTs cloning, transcriptome analysis, high-throughput screening, heterologous expression and folding are briefly discussed, showing some numbers of species and components already identified, but also shortly mentioning limitations and perspectives of research for the future in this field.
Asunto(s)
Péptidos/metabolismo , Venenos de Escorpión/genética , Venenos de Araña/genética , Animales , Clonación Molecular , Etiquetas de Secuencia Expresada/química , Etiquetas de Secuencia Expresada/metabolismo , Perfilación de la Expresión Génica , Biblioteca de Genes , Ensayos Analíticos de Alto Rendimiento , Péptidos/genética , Proteómica , Venenos de Escorpión/química , Venenos de Araña/químicaRESUMEN
Determinar la epidemiología y patogenicidad de Blastocystis hominis. Del total de muestras fecales analizadas (1.420), en el Laboratorio Clínico de la Escuela de Bioanálisis (LUZ), en 349 (24,6 por ciento) se evidenció B.hominis, a través del examen parasitológico directo. Posteriormente fueron seleccionadas aleatoriamente 77 (22 por ciento) muestras de pacientes de cualquier edad y sexo, que además fueron sometidas a una evaluación minuciosa de las firmas evolutivas de B.hominis mediante el examen fresco (400X), un método de cuantificación para B.hominis, y coloración permanente de Kinyoun, para el descarte de coccidios intestinales. Adicionalmente, se llenó una encuesta epidemiológica. B.hominis alcanzó una prevalencia de 24,6 por ciento. No se demostró diferencia significativa entre las variables parasitosis y la edad; observándose un predominio del monoparasitismo (59,7 por ciento). Se detectó asociación de afinidad entre B.hominis y Endolimax nana. Predominó la forma vacuolar (96,1 por ciento). El 84,4 por ciento de las muestras presentaron menos de cinco microorganismos por campo (400X). B.hominis se observó en individuos sintomáticos y asintomáticos; y las manifestaciones clínicas más comunes fueron: dolor abdominal, flatulencia, diarrea y náuseas. La mayoría de los pacientes refirieron consumir agua hervida y/o filtrada. Se observó una elevada prevalencia de B.hominis en la población investigada. No huvo asociación entre las variables parasitosis, edad y sintomatología. No se demostró asociación entre la presencia de cinco o más microorganismos por campo (400X) y los síntomas gastrointestinales
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Blastocystis hominis/patogenicidad , Epidemiología , Medicina Tropical , VenezuelaRESUMEN
Correlacionar las cargas parasitarias con el estado nutricional y manifestaciones clínicas en individuos infestados por Ascaris lumbricoides. Se analizó una muestra fecal de 128 individuos de ambos sexos, en edades comprendidas entre 4 y 12 años, pertenecientes a una comunidad marginal del municipio Maracaibo. Las muestras fueron procesadas mediante examen al fresco, concentración por formol-éter y recuento de huevos por Stoll y Kato-Katz; practicándoles conteo de vermes de Ascaris lubricoides postratamiento. Así mismo, se registró en una historia clínica todos los datos pertinentes al estudio. El mayor porcentaje de prevalencia para Ascaris lumbricoides fue 29,7 por ciento al utilizar en conjunto las técnicas coproscópicas con la recolecta de ejemplares adultos. El 84 por ciento de los individuos infestados, albergó pocas cargas del parásito. La intensidad promedio estimada a través de Kato-Katz, resultó severa, y moderada según número de vermes expulsados. Al confrontar las cargas parasitarias con estado nutricional y manifestaciones clínicas, no se observaron diferencias significativas. No hubo correlación directamente proporcional entre la severidad de las manifestaciones clínicas y la intensidad de la infestación, aún cuando el dolor abdominal predominó. Se observó una asociación de afinidad entre Ascaris lumbricoides y Trichuris trichiura
Asunto(s)
Humanos , Masculino , Femenino , Ascariasis , Parasitosis Intestinales , Enfermedades Pulmonares Parasitarias , Estado Nutricional , Medicina Tropical , VenezuelaRESUMEN
A medical occupational study was performed in 40 workers belonging to productive units in telecommunication works, 22 to car radiator mechanics and 11 to battery repairs. A practical medical and occupational study was applied to the group and also were determined their blood lead and air lead exposure levels. Seventy-three individuals, without risk of laboral exposure to lead, without familiar, pathological and occupational antecedents, and healthy at the time of the test, to whom the blood lead levels were determined served as control group. The mean values of plumbemia in exposure workers to inorganic lead exceed the level threshold of the COVENIN 2277-85 norm (30 micrograms/dl) (Telecommunication work, 40.10 micrograms/dl, radiators mechanics, 37.40 micrograms/dl and battery repairs, 45.77 micrograms/dl), values that were significantly higher (p < 0.0001) compared with the ones obtained in the non-exposed population. The factors that can influence the variability of the results were analyzed and it was established a correlation between the plumbemia of the radiator mechanics and battery repairmen and the length of occupational period and air lead levels (p < 0.0001). The inherent factors to the climatic, occupational and personal conditions of technicians in telecommunications, are presented as elements able to explain the lack of correlation between blood lead levels and length of occupational period and air lead. The clinical findings in exposed workers were unspecific. The workers do not practice or follow the basic sanitary regulations, personal protection and industrial security. This work will contribute to establish a basic description, to further and more complex observational prospective studies in order to determine the occurrence of alterations that are derived from occupational lead exposure.
Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Industria Química , Plomo/análisis , Metalurgia , Enfermedades Profesionales/inducido químicamente , Exposición Profesional , Telecomunicaciones , Adolescente , Adulto , Anemia/sangre , Anemia/inducido químicamente , Anemia/epidemiología , Artralgia/sangre , Artralgia/inducido químicamente , Artralgia/etiología , Humanos , Plomo/sangre , Persona de Mediana Edad , Enfermedades del Sistema Nervioso/sangre , Enfermedades del Sistema Nervioso/inducido químicamente , Enfermedades del Sistema Nervioso/epidemiología , Enfermedades Profesionales/sangre , Enfermedades Profesionales/epidemiología , Salud Laboral , Factores de Tiempo , Venezuela/epidemiologíaRESUMEN
In order to determine both clinical and spirometric changes due to high environmental concentrations of wheat dust at a wheat processing plant mill, 48 exposed men and 48 age and antroprometrically-matched, non-exposed apparently healthy men were studied. In both groups a medical and occupational history were taken, and spirometric measurements were carried out, that included Forced Vital Capacity (FVC), Forced Expiratory Volume at the first second (FEV1), Peak Flow Rate (PFR), Forced Percentual Expiratory Volume (FEV%), Forced Percentual Vital Capacity (FVC%), Forced Expiratory Flow at 25% (FEV25%), at 50% (FEV50%) and at 75% (FEV75%) of their Forced Vital Capacity, which were analyzed through Corzo's predictive equations and the lung deterioration's criteria by USA's Thoracic Association. The environmental wheat dust was determined by gravimetry and its concentration was higher than the legally admitted (3/5, 60%). There was a decrease in the PFR, FEV%, FEV25% and FEV75%. (p < 0.05). In addition, 4 restrictive and 1 obstructive syndrome were detected in the exposed workers and none in the control group. The spirometric values diminished in a positive correlation with the time of exposure and smoking habits. There was no correlation between the clinical findings and the dust concentration but it did exist with the spirometric values. It is concluded that in this plant, the wheat dust exposed workers have a diminished spirometric values.
Asunto(s)
Contaminantes Ocupacionales del Aire/efectos adversos , Polvo/efectos adversos , Harina/efectos adversos , Manipulación de Alimentos , Enfermedades Profesionales/diagnóstico , Neumoconiosis/diagnóstico , Hipersensibilidad Respiratoria/diagnóstico , Espirometría , Triticum , Adulto , Comorbilidad , Humanos , Mediciones del Volumen Pulmonar , Masculino , Enfermedades Profesionales/epidemiología , Enfermedades Profesionales/fisiopatología , Neumoconiosis/epidemiología , Neumoconiosis/fisiopatología , Pruebas de Función Respiratoria , Hipersensibilidad Respiratoria/epidemiología , Hipersensibilidad Respiratoria/fisiopatología , Fumar/epidemiología , Venezuela/epidemiologíaRESUMEN
In order to evaluate the respiratory health status in workers exposed to antigenic substances (chicken feathers, serum and dropping), typical of usual practice in the avian slaughter-house, pulmonary function was studied on 49 exposed workers, and in a sample of 49 people with similar anthropometric characteristics, non exposed to these substances, by means of occupational-medical history, spirometric tests, hematologic and biochemical tests, and postero-anterior chest x-rays. The values for the spirometric parameters varied with sex, age, weight, size, smoking habits, length of employment and exposure time, and there were no significant differences between exposed and control groups as a whole; showing significant differences with decreasing values for CVF, VEF1, PFE, FEF-25% and FEF-50% in the intermediate zone workers, and in subjects with short exposure time (< 1 year). Prevalence of clinical findings in the exposed population was significantly higher than the non exposed group (p < 0.001). Laboratory tests showed reduction of monocytes cells in the exposed group (p < 0.05) in addition, in the exposed women there was an increase of the eosinophiles, total proteins and globulines (p < 0.05). The frequency of radiographic findings was significantly higher in the exposed group (p < 0.006), and they were no specific. The lack of association between clinical findings, laboratory and radiographic findings, with the spirometric results, could be explained by the short period of exposure, individual and collectives hygienic conditions and size of the sample.