Dengue virus identification by transmission electron microscopy and molecular methods in fatal dengue hemorrhagic fever.

Dengue virus is the most significant virus transmitted by arthropods worldwide and may cause a potentially fatal systemic disease named dengue hemorrhagic fever. In this work, dengue virus serotype 4 was detected in the tissues of one fatal dengue hemorrhagic fever case using electron immunomicroscopy and molecular methods. This is the first report of dengue virus polypeptides findings by electron immunomicroscopy in human samples. In addition, not-previously-documented virus-like particles visualized in spleen, hepatic, brain, and pulmonary tissues from a dengue case are discussed.

Effect of policosanol on lipofundin-induced atherosclerotic lesions in rats.

Policosanol is a mixture of higher aliphatic alcohols isolated from sugar cane wax, showing cholesterol-lowering effects and preventing the development of lipofundin-induced lesions in New Zealand rabbits. This study was conducted to determine whether policosanol orally administered to rats also protects against the development of lipofundin-induced atherosclerotic lesions. Fifty four male Wistar rats were randomly distributed amongst a negative control group, a positive control group intravenously injected with lipofundin for eight days, and four experimental groups also injected with lipofundin, but orally receiving policosanol at 0.5, 2.5, 5 and 25 mg kg-1, respectively. Policosanol treatment was orally administered once-a-day for eight days, while control groups similarly received equivalent amounts of vehicle. A significant reduction of the atherosclerotic lesions in the treated animals was observed. It is concluded that policosanol has a protective effect on lipofundin-induced aortic lesions in Wistar rats.

Effect of policosanol on foam-cell formation in carrageenan-induced granulomas in rats.

Policosanol is a new cholesterol-lowering drug isolated and purified from sugar-cane wax, which prevents the development of lipofundin-induced lesions and foam-cell formation in New Zealand rabbits and Wistar rats. This study was conducted to examine the effects of policosanol on foam-cell formation in carrageenan-induced granulomas in rats. Eighteen Wistar rats were randomly distributed in three experimental groups which received orally for 20 days Tween 20 H2O as vehicle (control group) or policosanol at 2.5 or 25 mg kg-1. At the 11th day, lipofundin was injected intraperitoneally for 8 days to induce formation of foam cells in the granuloma. At day 13, carrageenan was injected subcutaneously for granuloma induction and seven days later animals were killed. A significant reduction of the foam-cell formation in granulomas of policosanol-treated rats was observed. It is concluded that policosanol prevents the development of foam cells in carrageenan-induced granulomas (extravascular medium) in rats.

Ultrastructural and immunocytochemical evidences of core-particle formation in the methylotrophic Pichia pastoris yeast when expressing HCV structural proteins (core-E1).

Particulate antigens of the Hepatitis C virus (HCV) are reported for the first time by transmission electron microscopy in Pichia pastoris. The yeast was cloned to express the first 339 NH2-terminal amino acids of the HCV polyprotein (C-E1.339 polypeptide). The C-E1.339 polypeptide covers the putative 191 aa of the core protein (aa 1-191) and 148 aa of the E1 envelope antigen (aa 192-339). Virus-like particles (VLP) with diameters ranging from 20 nm to 30 nm were specifically observed in those cells expressing the HCV polyprotein. The VLP appeared along the membrane of the endoplasmic reticulum, but were fundamentally localized in vacuoles, either free or inside autophagic bodies. Clustered particles, chains of particles, high-density reticular structures, and crystalloid bodies were also detected, the last one being an orderly arrangement of particles with 20 nm diameters. The crystal-associated particles are well differentiated from the intracellular VLP because of their uniform size and shape. We argue that membrane components are retained in the architecture of the VLP, conferring to this particle certain heterogeneity. Both kinds of particles, the VLP formed after treatment with NP-40 and the crystal-associated particles, were core protein-positives. Whether they reflect mature HCV nucleocapsid or intermediary states in the viral nucleocapsid morphogenesis remains unknown. We conclude that, like mammalian cell lines, the P. pastoris yeast could be an appropriate host for the analysis of HCV polyprotein processing and, eventually, virus assembly.

[Validation of a nutritional screening tool for hospitalized pediatric patients]. / Validación de una herramienta de cribado nutricional para pacientes pediátricos hospitalizados.

BACKGROUND: Malnutrition among hospitalized patients has clinical implications, and interest has arisen to find screening tools able to identify subjects under risk. At present, there is no consensus about the most suitable nutrition screening tool for pediatric patients. AIM: To validate STAMP (Screening Tool for the Assessment of Malnutrition in Pediatrics) pediatric screening tool in Spain. METHODS: Descriptive cross-sectional study of patients admitted to a 3rd level children's hospital with both medical and surgical specialities. During the first 24 hours of admission, STAMP screening tool was applied. For its validation, results were compared with those obtained from a nutritional assessment performed by specialist staff, which included clinical, anthropometric and body composition data. RESULTS: A sample of 250 children was studied. Nutritional assessment identified 64 patients (25.6%) under risk, 40 of whom were malnourished (16%). STAMP classified 48.4% of the patients as being under nutritional risk. This tool showed 75% sensitivity and 60.8% specificity when identifying patients under risk according to nutritional assessment. It showed 90% sensitivity and 59.5% specificity when identifying malnourished patients. COMMENTS: Malnutrition was less frequent than that reported in other European countries, although diagnosis technique was different. STAMP is a simple and useful tool for nutritional screening, avoiding the need to assess all patients on admission in order to identify those under nutritional risk.

Resistance to the antimicrobial agents of bacteria isolated from non-sterile pharmaceuticals.

The in vitro antimicrobial resistance of 391 bacterial strains isolated from 389 samples of oral and topical medicaments was examined. The numbers of strains isolated (and percentage of samples that present them) were: 234 Bacillus (32.1%), 79 Staphylococcus (13.6%), 46 Micrococcus (11.3%), nine Pseudomonas (1.5%), eight Acinetobacter (1.5%), five Enterococcus (1.2%), three Alcaligenes (0.8%), two Escherichia and Enterobacter (0.5%), one each Providencia, Serratia and Streptococcus (0.2%). Gram-positive bacteria were isolated from topical and oral medicaments and Gram-negative rods were detected only in topical medicaments. The 97.4% of Bacillus strains were resistant to lincomycin and B. cereus was resistant to beta-lactam and trimethoprim-sulphamethoxazole. Staphylococcus spp. showed a high percentage of resistant strains to ampicillin (51.8%), tetracycline (40.5%) and trimethoprim-sulphamethoxazole (48.1%). Staphylococcus epidermidis had the highest number of multiresistant strains. The 23.9% of Micrococcus strains were resistant to colistin. Enterococcus and Streptococcus strains showed multiresistance to penicillin G, aminoglycosides and erythromycin. The 61.5% of Gram-negative rod strains showed multiresistance to beta-lactam antibiotics and erythromycin; Pseudomonas spp. were the most resistant.

Heterotrophic bacterial populations in the mineral waters of thermal springs in Spain.

The microbiological quality and heterotrophic bacterial populations of 26 thermal mineral water springs in Spain were studied. In most of the springs the number of viable aerobes was less than 10(3) cfu ml-1 and the number of sporulated bacteria less than 10(2) cfu ml-1. No significant differences were found in the counts obtained with Plate Count Agar (PCA) and PCA diluted 1:10 and incubated at 22 degrees, 37 degrees and 45 degrees C. Total coliforms were found in 14 springs, faecal streptococci in three, spores of sulphite-reducing Clostridium and Pseudomonas aeruginosa in seven. Neither Escherichia coli nor Staphylococcus aureus were found. A total of 665 strains were isolated and 85.4% of these identified; 329 were Gram-positive and 239 were Gram-negative. The genera most prevalent present in the springs were Pseudomonas (in 92.3%), Bacillus (65.4%), Enterobacter, Micrococcus and Staphylococcus (50%), Acinetobacter (42.3%), Arthrobacter (38.4%), Clostridium (27%) and Xanthomonas (23%). Gram-negative bacteria predominated in the mesothermal springs and Gram-positive bacteria in the hyper- and hypothermal springs. The most common Gram-negative rod species isolated were Ps. fluorescens, Ps. aeruginosa, Ps. putida, Ent. agglomerans, Ent. sakazakii, Ac. calcoaceticus and Ent. amnigenus.

Enterotoxigenicity of Staphylococcus strains isolated from Spanish dry-cured hams.

The ability of 135 Staphylococcus strains isolated from Spanish dry-cured hams to produce enterotoxins in culture was investigated by the reversed passive latex agglutination method. A high percentage of enterotoxigenic Staphylococcus aureus strains (85.9%) was recorded, and 54.3% of these produced enterotoxin A. One of the two Staphylococcus epidermidis strains produced enterotoxin C. The reversed passive latex agglutination method yielded satisfactory results.

Microbiological quality of pharmaceutical raw materials.

A total of 115 samples of pharmaceutical raw materials (excipients) were analysed: 36 lactose, 27 talc, 19 corn starch, 18 arabic gum, 8 gelatin, 3 gelatinized starch, 3 cellulose and one tragacanth gum. 69.9% of the samples showed less than 10(2) bacteria/g (mean = 23.2 cfu/g) and 95.2% less than 10(2) fungi/g (mean = 4.92 cfu/g). Arabic and tragacanth gum were the most contaminated products by bacteria and fungi, respectively. Pregelatinized starch, cellulose and lactose were the least contaminated excipients. In none of the samples Escherichia coli or Salmonella-Shigella were detected; however, strains of Enterobacter, Serratia and Proteus were isolated from 10 samples of 5 different excipients. Only 5 samples did not comply with the microbiological standards as established by the European Pharmacopoeia and USP.

Numerical taxonomy of Bacillus isolated from orally administered drugs.

Numerical taxonomy procedures were used to study 118 strains of Bacillus isolated from non-sterile drugs prepared for oral administration. Similarities between pairs of strains were calculated by the simple matching coefficient of Sokal and Michener (SSM). Each strain was tested for 60 unit characters and three clusters were defined. The strains in each cluster presented a similarity level of at least 60%. Cluster A comprised the strains identified as Bacillus cereus (SSM = 93.13%), cluster B contained three subgroups corresponding to the species B. pumilus, B. subtilis and B. licheniformis (SSM = 84.35%) and cluster C also included three subgroups that belonged to the species B. firmus, B. lentus and B. badius (SSM = 80.14%). The most discriminating tests were selected to differentiate the clusters from the subgroups. The feature with the highest discriminating power between clusters A and B was the lack of acid production from arabinose and mannitol. The Voges-Proskauer, methyl red tests and sensitivity to polymyxin B clearly distinguished cluster A from C. The Voges-Proskauer test and acid production from arabinose were the best to differentiate between B and C. Bacillus pumilus and B. subtilis differed in starch hydrolysis and B. licheniformis in growing anaerobically. To discriminate B. firmus from B. lentus the most important tests were the acid production from glucose and sucrose; intermediate strains were found. Bacillus badius was differentiated from B. firmus by 10 tests, and from B. lentus by the production of urease.

Characterization of Bacillus cereus strains isolated from drugs and evaluation of their toxins.

The microbial contamination of 68 samples of topical and 324 samples of oral medicaments has been studied. The most common group of contaminants was members of the genus Bacillus (34.4%). Because of the pathogenic significance of B. cereus, 39 strains were characterized by morphology and biochemical properties. All except three showed most of the characteristics of the type strain. They were highly resistant to lincomycin, polymyxin B and penicillin G-cephalosporin and were susceptible to streptomycin, erythromycin and chloramphenicol. Enterotoxin, phospholipase C and haemolysin production were also studied: 33 strains gave a positive vascular permeability reaction, four of them causing necrosis, and 24 showed positive mouse lethal tests. All the strains had phospholipase activity. The majority also exhibited differing degrees of haemolysis. Permeability factor was related to mouse lethality and haemolytic activity. Phospholipase C was not related to any of the above activities.

Characterization of a virus isolated from the cerebrospinal fluid of patients with epidemic neuropathy.

A previously unknown disease, termed epidemic neuropathy (EN), occurred in Cuba between 1991 and 1993. When samples of cerebrospinal fluid (CSF) from 45 patients with EN and 11 controls were inoculated into cultures of VERO cells, almost all (93%) of the samples from the cases of EN but only one (9%) of the control samples produced a slowly progressing cytopathological effect (CPE). Although the results of other studies indicated the presence of a picornavirus-like virus in CSF samples from EN cases, the CPE and other physico-chemical characteristics observed were not those expected of picorn-viruses. Several aetiological factors may have contributed to EN but at least one virus could have played a major role.

Characterization of the HCV core virus-like particles produced in the methylotrophic yeast Pichia pastoris.

Little is known about the mechanism of hepatitis C virion assembly. So the capacity of the entire Hepatitis C virus core protein (HCcAg) produced in Pichia pastoris to form particles either in its native soluble state or after detergent treatment of HCcAg associated to cell debris were studied. Size exclusion chromatography suggested that HCcAg assembled into high molecular weight structures. HCcAg was also specifically recognized by a serum from a chronic HCV carrier patient. This antigen migrated with buoyant density values similar to those obtained for native nucleocapsid particles from infected patients when analyzed using sucrose density gradient centrifugation. The analysis by electron microscopy of purified HCcAg showed aggregates resembling virus-like particles (VLPs) with an average diameter of 30 nm. These results indicated that the HCcAg obtained from P. pastoris assembled into VLPs resembling HCV nucleocapsid particles in a mature stage. Such HCcAg aggregates characterized here could be a valuable tool to elucidate the mechanisms of HCV nucleocapsid assembly.

Assembly of truncated HCV core antigen into virus-like particles in Escherichia coli.

Core protein is one of the most conserved and immunogenic of the hepatitis C virus proteins. Several pieces of experimental evidence suggest its ability for formation of virus like particles alone or in association with other viral proteins in mammalian or yeast cells with great similarity to those detected in patient sera and liver extract. In this work we report an Escherichia coli-derived truncated hepatitis C core protein that is able to aggregate. SDS-PAGE and size exclusion chromatography patterns bring to mind the aggregation of monomers of recombinant protein Co.120. The Co.120 protein migrated with buoyant density of 1.28 g/cm(3) when analyzed using CsCl density gradient centrifugation. Spherical structures with an average diameter of 30 nm were observed using electron microscopy. We report here that VLPs are generated when the first 120 aa of HCV core protein are expressed in E. coli.

Fórmulas de nutrición enteral pediátrica. ¿Cómo elegir la adecuada? / Formulas of pediatric enteral nutrition. How to chose the right one?

La elección de la fórmula es la fase más importante al instaurarla nutrición enteral. Puesto que los requerimientos nutricionales y energéticos del niño no son los mismos que en el adulto, existen diferentes preparados adaptados a la etapa pediátrica y, dentro de ésta, a los distintos grupos de edad. Además, en los últimos años se han comercializado nuevos tipos de fórmulas, como dietas específicas para las enfermedades en la edad pediátrica o dietas poliméricas para lactantes. Esta variedad de preparados nos permite ahora, más que nunca, individualizar la nutrición de nuestros pacientes. El objetivo de este artículo es revisar, clasificar y establecer las indicaciones para las distintas fórmulas existentes actualmente en el mercado español(AU)

The choice of the correct nutritional formula is the most important phase when establishing enteral nutrition. Given that children´s energy and protein requirements are not the same as those in adults, there are different formulations adapted to the pediatric stage and within this, to different age groups. Furthermore, in recent years new types of formulas have been commercialized, as special foods or polymeric formulas for infants. This variety of formulas has allowed us to individualize nutritional support in pediatric patients. The aim of this article is to review, classify and establish the indications for the different formulas available at this time in the Spanish market(AU)

Consideraciones prácticas sobre la nutrición enteral en el recién nacido prematuro / Practical considerations about enteral nutrition in the premature newborn

El recién nacido prematuro presenta características nutricionales y funcionales diferenciales que, según el peso al nacimiento y la edad gestacional, serán la base para llevar a cabo su soporte nutricional. Una nutrición precoz y eficaz mejora el pronóstico. El mantenimiento de un crecimiento extrauterino adecuado, el aporte óptimo de energía y el descenso de la morbilidad precoz serán los tres objetivos fundamentales de la nutrición artificial. En este artículo se exponen los requerimientos de energía, líquidos, proteínas, hidratos de carbono y lípidos en este tipo de pacientes. Además de aportar sustrato energético, la nutrición enteral también estimula la mucosa intestinal, influye en la adquisición apropiada de una microbiota y ayuda a conseguir un buen vínculo madre-hijo, así como una adecuada maduración psicomotora. Se revisan los diferentes procedimientos de alimentación, así como la progresión a nutrición enteral total, la intolerancia digestiva en estos pacientes y el tipo de alimentación al alta(AU)

Premature newborns have especial functional and nutritional characteristics that, depending on their birth weight and their gestational age, are the basis to carry out their nutritional support. They need an effective and precocious nutrition in order to improve their outcome. The maintenance of an adequate extra uterine growth, anoptimum energy intake, and a decrease of early morbidity are the main objectives of artificial nutrition. Energy, fluid, proteins, carbohydrates and lipids requirements of this kind of patients are shown in the present article. As well as energetic substrate, the enteral nutrition also stimulates the intestinal mucosa, influencing the acquisition of an appropriate microbiota, and it helps to create an appropriate bond between mother and baby and a suitable psychomotor maturation. The different feeding procedures for these patients are reviewed as well as the progression way to complete enteral feeding, the digestive intolerance and the selection of a diet before hospital discharge(AU)

Cálculo de los requerimientos energético-proteicos para el soporte nutricional en la práctica clínica / Estimation of energy and protein requirements to design nutritional support in clinical practice

La estimación precisa de los requerimientos de energía es muy importante cuando se programa un soporte nutricional; un adecuado aporte nutritivo contribuirá a un mejor manejo clínico. Además, los pacientes pediátricos necesitan tener un adecuado aporte de proteínas, que cubra los requerimientos necesarios para el crecimiento. La última meta del soporte nutricional en los lactantes y niños es lograr una retención nitrogenada y un balance de energía neutro. El gasto energético basal (GEB) es el parámetro más representativo del metabolismo y el principal componente del gasto energético total diario. Cuando las técnicas de calorimetría no están disponibles, existen ecuaciones predictivas que pueden aplicarse para determinar su valor. Para estimar el gasto de energía diario, el GEB debe multiplicarse por el factor de nivel de actividad física, que incluye el gasto de energía debido a la actividad física, crecimiento y respuesta metabólica a los alimentos. En caso de enfermedad, existen posibles cambios en el GEB y el nivel de actividad física, así como una inusual pérdida de energía, que deben tenerse en cuenta cuando se tratad e encontrar los requerimientos de energía. Entre las necesidades adicionales en el caso de pacientes malnutridos se incluye la energía necesaria para la recuperación nutricional. En este trabajo se comentan distintos aspectos relacionados con los requerimientos de energía y proteínas estimados en la lactancia y la niñez (AU)

Accurate estimation of energy requirements is important when programming nutritional support, as adequate nutrient intake will contribute to a better clinical course. In addition, pediatric patients need to maintain a proper protein intake, necessary to meet their growth requirements. The ultimate aim of nutritional support in infants and children is to achieve nitrogen retention and neutral energy balance. Basal metabolic rate (BMR) is the most representative parameter of metabolism and represents the major component of energy expenditure. When calorimetry techniques are not available, predictive equations can be applied to determine its value. To estimate daily total energy expenditure, BMR can be multiplied by the physical activity level factor, which includes the energy expenditure derived from physical activity, growth and metabolic response to food. In case of illness, possible changes in BMR and physical activity level, as well as unusual energy losses, must be taken into account when estimating energy requirements. Additional needs of malnourished patients include the necessary energy for nutritional recovering. Different aspects concerning the estimation of energy and protein requirements in infants and children are discussed in this issue (AU)