Active prokaryotic population dynamics exhibit high correlation to reactor performance during methane production from acid hydrolysates of Agave tequilana var. azul bagasse.

AIMS: The purpose of this study was to apply cDNA approach for the characterization of active prokaryotic community to understand microbial scenarios and performance of an AnSBR digester fed with acid hydrolysates of Agave tequilana var. azul bagasse (ATAB). METHODS AND RESULTS: The digester was implemented for methane production under organic loading rate (OLR) disturbances to correlate physicochemical variables with changes in abundance, diversity and population dynamics of active Bacteria and Archaea by principal components analysis (PCA). Results indicated that methane yield increased as well as active syntrophic relationships for interspecies hydrogen/formate (Anaerolinaceae-Methanobacterium beijingense) and acetate (Anaerolinaceae-Methanosaeta concilii) transfers at 8 g-COD l-1  day-1 . However, methane yield was negatively affected at 16 g-COD l-1  day-1 due to the competition for acetate by active Desulfovibrio marrakechensis and volatile fatty acids inhibition. CONCLUSIONS: Microbial scenarios obtained by PCA correlations indicated that methane production from acid hydrolysates of ATAB was feasible at 8 g-COD l-1  day-1 . The digester operation at higher OLR only favoured methanogenesis by the hydrogenotrophic pathway. SIGNIFICANCE AND IMPACT OF THE STUDY: Only cDNA analysis showed Archaea population dynamics, exhibiting high correlation with physicochemical variables towards the understanding of the methanogenic digester performance during OLR disturbances.

Comparison of two analytical methods validated for the determination of volatile compounds in virgin olive oil: GC-FID vs GC-MS.

The utility of volatile compounds to explain virgin olive oil aroma descriptors is fully accepted and demanded by the olive oil sector. However, the methodology, and particularly the kind of detector to be used, is a matter of discussion because the high number of volatiles and their different nature. The SPME-GC-MS method has recently been validated for the most relevant volatiles but SPME-GC-FID method still needs to be validated to evaluate its performance in this application. A comparison between these two GC methods in determining 26 volatiles has been carried out in terms of analytical quality parameters (repeatability, intermediate precision, calibration curves, limits of detection and quantification, linear working ranges, selectivity and sensitivity). Good selectivity, linearity and higher upper values of the working range are the main advantages of SPME-GC-FID versus low bottom values of working ranges, better sensitivity and lower limits of detection and quantification of SPME-GC-MS. The limit of blank associated to each individual volatile was also determined and it allowed perfecting the empirical limit of detection. This procedure was carried out for SPME-GC-FID, which resulted in 21 volatiles with empirical limits of detections lower than their odor thresholds, and hence they can be used as markers of virgin olive oil sensory descriptors. Finally, with all the analytical quality parameters checked, a practical example of the ability of the volatiles quantified by SPME-GC-FID to discriminate the different categories (extra-virgin, virgin and lampante) and their main aroma descriptors is also provided.

Validation of SPME-GCMS method for the analysis of virgin olive oil volatiles responsible for sensory defects.

Volatile compounds are responsible for the aroma of virgin olive oil and also for its quality. The high number and different nature of volatile compounds drive to the need of a reliable analytical method that allows their proper quantification to explain the standard method of panel test. Although there are some analytical solutions available, they have not been validated and the regulatory bodies are reluctant to adopt them since they can be subjected to unknown errors. In this regards, the European Union has encouraged the validation of these analytical tools through the research program Horizon2020, which involves gaining knowledge from the analytical properties of the chemical methods for sensory assessment. This work is focused on the analytical validation of the methodology used to determine the actual concentration of volatiles in virgin olive oils when applying SPME-GCMS. The validation process includes the calibration curves for 29 volatile compounds responsible for the most common sensory perceptions in virgin olive oils, the determination of their working ranges with linear response, the detection and quantification limits, the sensitivity, the accuracy estimated as trueness and precision and the selectivity. Sixty-seven percent of the compounds presented a relative standard deviation in repeatability lower than 10%, and this percentage rises to 95% in lampante virgin olive oils. The accuracy was established in 97% of the studied volatile compounds. Finally, an empirical example of the ability of the method to discriminate virgin olive oils of different categories (extra virgin, virgin, ordinary and lampante) by the quantification of their volatiles is provided.

[Peculiarities of meningoencephalitis caused by Angiostrongylus cantonensis in America]. / Peculiaridades de la meningoencefalitis por Angiostrongylus cantonensis en América.

INTRODUCTION: 25 years ago was first reported in Cuba and in the western hemisphere an emergent disease: eosinophilic meningoencephalitis due to Angiostrongylus cantonensis larvae. AIM: To collect in a summary form the accumulated experience and the findings of the study of this parasitosis during the period in the Western hemisphere. DEVELOPMENT AND CONCLUSIONS: There have been collected the first evidences, the parasitological and malacological findings, the experimental and molecular studies on immunology and neuroimmunology, the clinic-pathological findings in children and adults with the particularities of this diseases in our environment with special emphasis in the never-before scientific findings reported. It has been documented the testimony, the main findings among the malacological studies, the role of the immunoglobulin E and the mechanism involved in the central nervous system, the intrathecal synthesis patterns of immunoglobulins and the clinical elements in children and adults.

Detection of the presence of refined hazelnut oil in refined olive oil by fluorescence spectroscopy.

The fluorescence spectroscopy technique has been tested as regards its ability to differentiate between refined hazelnut and olive oils. Classification of these oils based on their excitation-emission fluorescence spectra data (spectral range 300-500 nm of the excitation spectra at lambdaem=655 and spectral range 650-900 of the emission spectra at lambdaex=50 nm) was performed using principal component analysis and artificial neural networks. Both methods provided good discrimination between the refined hazelnut and olive oils. The results have also pointed out the possibilities of a spectrofluorimetric method joined to multivariate analysis, to differentiate refined oils, and even to detect the presence of refined hazelnut oils in refined olive oils at percentages higher than 9%.

Changes induced by UV radiation during virgin olive oil storage.

The effects of UV radiation on the chemical and sensory characteristics of virgin olive oils (cv. Arbequina and Picual) were assessed. Even small doses of UV radiation induced oxidation of the virgin olive oil samples. Total phenols and fatty acids contents decreased during the process as well as the intensity of the bitter and fruity sensory attributes, while the intensity of the rancid sensory attribute notably increased. Acetaldehyde, 2-butenal, 2-pentenal, octane, octanal, hexanal, nonanal, and 2-decenal were the volatile compounds most affected, showing an important increase during the irradiation process. Nonanal, hexanal, and pentanal showed high correlation with the rancid sensory attribute (90%, 86%, and 86%, respectively). 2-Decenal and nonanal concentrations allowed us to predict the alteration level of the samples by mean of multiple Ridge regression.

[Intrathecal synthesis pattern of immunoglobulins in meningoencephalitis epidemic due to echovirus 9]. / Patrones de síntesis intratecal de inmunoglobulinas en epidemia de meningoencefalitis por echovirus 9.

INTRODUCTION: Epidemics of meningoencephalitis due to echovirus 9 were commonly occurred when a children population become susceptible for the first time in front the virus. OBJECTIVE: To present the intrathecal synthesis pattern of immunoglobulins of the epidemic that affected Cuba in 1999 and to probe the usefulness of reibergram and antibody index in the diagnostic and characterization of the outbreak. PATIENTS AND METHODS: 23 pediatric patients suffering from viral meningoencephalitis due to echovirus 9 were studied in the income moment. Serum and cerebrospinal fluid IgA, IgM, IgG, albumin and glucose were quantified. Cerebrospinal fluid total protein content and lactate were quantified. Titles of antibodies against echo 9 and Coxsackie A9 and differential cell count were performed. RESULTS: A mean of 555 cells/10 6 L mainly lymphocytes were obtained. Glucose in cerebrospinal fluid was over 50%, serum glucose and lactate levels below 2.1 mmol/L. In the reibergram an absence of intrathecal synthesis was predominant (15/23), IgM synthesis (6/23) and IgM+IgA (2/23). Blood cerebrospinal fluid dysfunction was observed in 15 patients. The mean antibody index was 1,8 for echo 9 and 0,9 for Coxsackie A9. CONCLUSIONS: The intrathecal synthesis pattern of immunoglobulins was different from other enterovirus and from echovirus 9 in non epidemic situations before this epidemic, probably with alteration of viral genome.

[Neuroimmune epidemiological value of reibergram in the first echovirus 16 meningoencephalitis outbreak in Cuba]. / Valor neuroinmunoepidemiologico del reibergrama en la primera epidemia de meningoencefalitis por echovirus 16 en Cuba.

INTRODUCTION: During the third quarter of 2000, an outbreak of echovirus 16 meningoencephalitis was firstly occurred in Cuba and produced vomiting, headache, fever and exanthem that differentiate it from other enterovirus epidemies. OBJECTIVE: To describe the intrathecal immunoglobulin synthesis pattern of the epidemie from the reibergram. PATIENTS AND METHODS: Diagnostic serum and cerebrospinal fluid from 18 children during the acute phase by nephelometrie assay, besides cytochemical and virological study. RESULTS: A predominant absence of intrathecal immunoglobulin synthesis and two patients with IgA and IgM synthesis was produced. 66% of cerebrospinal blood barrier dysfunction, 6.26 10 3 mean albumin ratio, lactate below 2.1 mmol/L and glucose concentration in cerebrospinal fluid was 50% over glucose blood content and 168 cells 10 6 L mainly lymphocytes were observed. CONCLUSIONS: The intratecal immunoglobulin synthesis pattern differs from other enterovirus outbreaks that have affected this population and it seems the one found for the diagnostic period in adults. This finding alerts the possibility of genetic changes in echovirus 16 strain, interesting from the neuroimmunoepidemiological point of view.

[Patterns of immunoglobulin synthesis in pediatric patients with Coxsackie A9 meningoencephalitis during the neuropathy epidemic in Cuba]. / Patrones de síntesis de inmunoglobulinas en pacientes pediátricos con meningoencefalitis por Coxsackie A9 durante la epidemia de neuropatía en Cuba.

INTRODUCTION: Simultaneously with the origin and development of the Cuban epidemic neuropathy, cases of viral meningoencephalitis with particular characteristics due to Coxsackie were found. This virus and Inoue-Melnick virus were found too in patients suffering from Cuban epidemic neuropathy. PATIENTS AND METHODS: 31 pediatric patients suffering from viral meningoencephalitis were studied. Albumin, IgA, IgM and IgG were quantified in serum and cerebrospinal fluid by nephelometry. Cytochemical studies and reibergrams were performed. RESULTS: There was a lymphocyte predominance in cerebrospinal fluid. A dysfunction of blood-cerebrospinal fluid barrier was shown in 10 patients. Twenty patients have no immunoglobulins intrathecal synthesis. The synthesis patterns were: five patients with local IgM synthesis, two patients with local IgG synthesis and IgA + IgM. IgA + IgG and IgA + IgM pattern was synthesized in one patient respectively. Two patients with low IgG synthesis percentage or IgG intrathecal fractions were reported. CONCLUSIONS: The absence of immunoglobulins intrathecal synthesis and the immunoglobulins synthesis patterns differ from other pediatric patients with enterovirus meningoencephalitis. These patterns may have relationship with modified antigenic characteristics of the virus, also found in Cuban epidemic neuropathy.

IgG2 immunodeficiency: association to pediatric patients with bacterial meningoencephalitis.

An IgG subclass deficiency is often associated with bacterial infections. We studied four pediatric patients suffering from meningoencephalitis, two of them due to Streptococcus pneumoniae and two due to Haemophilus influenzae type b. Simultaneous diagnostic serum and cerebrospinal fluid samples were taken during income. The four subclasses of IgG and albumin were quantified in both biologic fluids by radial immunodiffusion. Very low levels of seric IgG2 with non detectable cerebrospinal fluid IgG2 were found in the patients. No intrathecal IgG subclass synthesis was found in two patients. One patient with S. pneumoniae had IgG3 intrathecal synthesis. Intrathecal IgG1, IgG3 and IgG4 synthesis was found in one patient suffering from H. influenzae according with reibergrams. Substitutive therapy with intravenous gammaglobulin was given to the patients as part of the treatment.

Detection of rancid defect in virgin olive oil by the electronic nose.

A sensor array of 32 conducting polymer sensors has been used to detect the rancid defect in virgin olive oils. A training set, composed of admixtures of a Portuguese virgin olive oil with different percentages (0-100%) of a rancid standard oil, was used for the selection of the best sensors classifying correctly the samples. Information on volatile compounds responsible for rancidity and the sensory evaluation of samples by assessors were used for explaining the mathematical selection of sensors. A tentative calibration, using unsupervised procedures (PCA and MDS) and a nonlinear regression, was carried out, with the training set, and later confirmed with a test set with which rancid commercial samples of different varieties were used to spike a Greek extra virgin olive oil at low levels of rancidity (0.5-6%).

Mammary gland sympathetic innervation is a major component in type 1 deiodinase regulation.

Recent observations have shown that in lactating rats previously deprived of suckling, either suckling stimulus or ip injection of norepinephrine was capable of increasing mammary deiodinase type 1 (M-D1) mRNA content and enzyme activity. In the present work, we show that intact efferent sympathetic mammary innervation is required to restore both mammary D1 mRNA content and enzyme activity, whereas suckling-induced secretion of catecholamines from the adrenal glands does not seem to participate in M-D1 enzyme regulation. The data also indicate that the sympathetic reflex activation in response to suckling involves two complementary autonomic components: (1) activation, presumably through mammary segmental arrangement affecting neighboring mammary glands; and (2) an individual reflex regulatory mechanism capable of maintaining M-D1 activity within each mammary gland. In addition to these findings, we show that the suckling-induced sympathetic activation of M-D1 activity could be blocked by prior activation of ductal mechanoreceptors. This set of regulatory and counterregulatory mechanisms seems to ensure the optimal control of mammary energetic expenditure according to litter size.

[Beta trace protein in the cerebrospinal fluid and serum in meningoencephalitis]. / Proteína beta traza en líquido cefalorraquídeo y suero en meningoencefalitis.

INTRODUCTION: beta-trace protein or D2 prostaglandin synthase is a dual functional protein. Its role and clinical value in cerebrospinal fluid is under study. MATERIAL AND METHODS: Seventy four pediatric patients suffering from viral meningoencephalitis and 7 with bacterial meningoencephalitis were studied. Sera and cerebrospinal fluid samples were taken. Albumin and beta-trace protein were quantified by immunodiffusion and nephelometry respectively. RESULTS: Increased cerebrospinal fluid beta-trace protein levels in comparison with normal value were observed. Nevertheless such expected increment was no possible seen in bacterial meningoencephalitis. CONCLUSIONS: beta-trace protein may contribute with the etiological diagnosis in meningoencephalitis.

Effects of centrally administered prolactin upon mammary contractility in anesthetized lactating rats.

The possibility was investigated that centrally administered rat prolactin (PRL), i.e., intracerebroventricularly (ICV) or intrathecally (IT), may influence mammary contractility in urethane-anesthetized lactating rats. In addition to the monomer (23 kD PRL), the 16- and 7-kD PRL fragments were also tested and their effects were determined on isometrically recorded intramammary pressure (IMP) responses to exogenous oxytocin (OXY). ICV injection of 23 kD PRL provoked increased IMP responses; similar, but inconsistent effects were obtained after 16 kD PRL, and no effect occurred after either saline or the 7 kD PRL fragment. The 23 kD PRL effect had a latency of about 5 min, reached plateau at 10-15 min and its magnitude was dose-dependent. Also, a stronger dose-related effect was shown by 23 kD PRL after IT than after ICV administration, which suggests that lower threshold for the PRL actions exist at the spinal level. On the other hand, ICV or IT injections of antiserum to PRL, but not of normal rabbit serum, fully prevented the respective facilitatory effects of 23 kD PRL on mammary contractility. Further experiments into the mechanisms involved showed that neither adrenalectomy nor hypophysectomy prevented the PRL effect whereas complete blockage occurred after either spinal cord transection, ventral root section (T8-T10 level), or i.v. or ICV administration of the adrenergic beta-blocker propranolol. These results indicate that central effects of PRL upon mammary contractility were neurally mediated and may have resulted from depressed beta-adrenergic control of ductal tone.

Central effects of catecholamines upon mammary contractility in rats are neurally mediated.

We injected, i.e., intracerebroventricularly (ICV) or systematically, small amounts of adrenaline (ADR), noradrenaline (NA), isoproterenol (ISOP) and dopamine (DA) in urethane-anesthetized lactating rats, and determined the effects on isometrically recorded intramammary pressure (IMP) responses to exogenous oxytocin (OXY). While centrally administered ADR, NA and DA provoked increased IMP responses to OXY, the beta-adrenergic agonist ISOP induced the opposite effect. These effects were reversible, dose related and also occurred in hypophysectomized rats. However, when injected systematically, all adrenergic agonists but DA depressed IMP responses to OXY. Further experiments showed that central effects of catecholamines were exerted by regulating ductal tone, through the direct innervation of the mammary glands. Thus, whereas complete blockage of these effects occurred after selective denervation of the mammary glands, increased ductal tone resulted from ICV administration of ISOP. Finally, evidence was also obtained that antagonistic alpha- and beta-adrenergic mechanisms may interact with each other to regulate milk ejection, and with afferent signals from the mammary glands. Thus, beta-adrenergic inhibition upon IMP was counteracted by either NA administration or by activation of ductal mechanoreceptors. Together, these results suggest that regulation of milk ejection may involve neurally mediated influences on mammary contractility. Such actions would interact closely with afferents from the mammary gland influencing ductal tone.

Changes in molecular variants during in vitro transformation and release of prolactin by the pituitary gland of the lactating rat.

PRL transformation involves a dopamine (DA)-controlled, thiol-mediated decrease in pituitary PRL detectability that precedes and may determine increased PRL release. The present studies were designed to determine 1) whether structural changes occur to adenohypophyseal (AP) PRL during in vitro transformation and may account for decreased PRL detectability; 2) whether such changes occur within AP PRL granules; 3) the type and proportion of secreted PRL variants; and 4) the influence of DA and/or thiol reducing agents upon AP PRL molecular changes. Quartered APs of 8 h nonsuckled lactating rats, injected or not with [3H]leucine (5 mCi/g body wt, 8 h before death) were incubated for 30-240 min. The effects of DA (50 microM) with or without reduced glutathione (10 mM), and the alkylant N-ethylmaleimide (1 mM) were compared to the changes in PRL molecular variants occurring in control incubated AP fragments. Polyacrylamide gel electrophoresis (PAGE) under native conditions and sodium dodecyl sulfate (SDS)-PAGE under reducing (R) or nonreducing (NR) conditions were used to resolve molecular variants of PRL and [3H]PRL, followed by Western blotting and densitometric/liquid scintillation techniques, respectively. Up to 5 and 10 major forms of immunoreactive PRL were resolved by PAGE and SDS-PAGE, respectively. The spontaneous transformation after 30 min incubation was correlated with a decrease of 23K PRL and 23K [3H]PRL bands and an increase in high mol wt (80 to greater than 100K) PRL forms. These changes were reversible upon reduction of the proteins before electrophoresis or after extraction of preparative gels. DA and N-ethylmaleimide prevented, whereas reduced glutathione induced these changes. Similar changes were observed in isolated granules from nonincubated and incubated pituitary fragments. Secreted PRL was also polymorphic, with a high predominance of 23K PRL and 23K [3H]PRL. In addition, a polymeric PRL variant, which in reducing gels showed an apparent mol wt of 27K, was secreted in high proportion, similar to that of 23K PRL. The nature of this polymeric variant of PRL is unclear at present. Altogether, these results suggest that a dynamic interconversion of PRL molecular variants occur during transformation. The decreased detectability associated with PRL transformation appears to involve the association of 23K PRL molecules into a 80 to greater than 100K disulfide-linked oligomer. This association is reversible upon reduction and takes place within secretory granules. DA appears to inhibit PRL transformation by preventing thiol-disulfide interchange.

Spectrophotometric determination of bismuth in pharmaceutical preparations using 1-[di(2-pyridyl)--methylene]-5-salicylidene-thiocarbonohydrazide.

A simple and fast spectrophotometric method for the determination of bismuth in pharmaceutical preparations is described. The used chromatic reactive is 1-[di(2-pyridyl)methylene]-5-salicilydene-thiocarbonohydrazide+ ++ forming a yellow complex with bismuth. In a solution containing 40% v/v of dimethylformamide molar absorption is 5.7 x 10(4) l.mol-1.cm-1 at 421 nm and at pH 4.3. The optimal conditions for the color development and the possible interferences are studied.