Chronic low back pain: diagnostic approach for primary care

Antecedentes: El dolor lumbar es uno de los principales motivos de consulta en el primer nivel de atención, requiere múltiples intervenciones diagnósticas, así como la adopción de conductas terapéuticas, e incluso, conlleva discapacidad en los pacientes adultos. Objetivo: Brindar una aproximación clínica con orientación diagnóstica para el abordaje de los pacientes con un motivo de consulta frecuente en el primer nivel de atención. Resultados: Los autores proponen un algoritmo para el abordaje clínico del paciente con dolor lumbar crónico, orientando, además, hacia generalidades de los exámenes complementarios (química sanguínea, imágenes diagnósticas, entre otros), para evaluar en un primer nivel al paciente que acude por esta patología. Conclusiones: La propuesta presentada en este artículo permite guiar al personal médico de primer nivel de atención a través de una aproximación enfocada en las características semiológicas del dolor, así como poder correlacionar con los diagnósticos más frecuentes, a fin de remitir o dirigir al paciente de acuerdo con las necesidades particulares correspondientes.

Keywords: Background: Low back pain is one of the main complaints in primary care reported by-patients, requiring several diagnostic interventions, therapeutic approaches and even entailing disability in young adults. Objective: To provide a clinical approach, diagnostically oriented, for patients frequently consulting primary care. Results: Of the authors propose a clinical algorithm for the clinical assessment of the patient with chronic low back pain, also considering complementary tests (imaging, blood chemistry, etc.) for the evaluation in primary care of the patient with this pathology. Conclusions: The proposal provided in this article helps guide the primary care physician through an approach focusing on the semiological characteristics of pain, so that they can correlate with the most frequent diagnoses, in order to refer or direct the patient according to their particular needs.

Effect of the Concentration, pH, and Ca2+ Ions on the Rheological Properties of Concentrate Proteins from Quinoa, Lentil, and Black Bean.

Given consumer trends propelling a movement toward using plant protein in the food industry and searching for alternative protein ingredients by the industry, this study aimed to assess the influence of factors such as protein concentration, medium pH, and the presence of a divalent ion (Ca2+) upon the rheological properties such as viscosity change and gel formation of dispersion proteins extracted from quinoa, black beans, and lentils. A solution of each protein was prepared by varying its concentration (2.5%, 5.0%, and 10%), the pH (5.0, 7.0, and 9.0), and the incorporation of calcium chloride (0.0% and 1.0%). Each obtained solution was subjected to rheological tests to determine the parameters: consistency index (K), flow behavior (n), the storage (G') and loss (G'') modules, and the phase shift angle (δ). The results demonstrate that the incorporation of Ca2+, the shift in protein levels, and the decrease in pH modified the rheological behaviors of proteins, which were also influenced by the structural characteristics of each protein studied. However, thermal treatment and protein concentrations caused the most significant impact on proteins' rheological behavior, forming gels independently of other conditions. It was possible to study and interpret the studied proteins' rheological variations according to the environment's conditions.

Innovative Process Coupling Short Steam Blanching with Vacuum Flash-Expansion Produces in One Single Stage High-Quality Purple Passion Fruit Smoothies.

Short steam blanching coupled with flash-vacuum expansion (FVE) and de-pulping was used to obtain purée from purple passion fruits discarded from the export chain. Different steam blanching holding times (80, 95, 110 s) were tested at pressure of 130 kPa. After FVE and vacuum de-pulping, fibers, anthocyanins, carotenoids, rheological properties, and microbial reduction were evaluated in the purées. Fruit purées are obtained with a much higher content of cell-wall and bioactive compounds compared to the fresh arils since part of the fruit shell is incorporated into the purée (approximately 20%), which greatly increases the yield of production. Purées exhibited increasing shear-thinning flow behavior with blanching holding time, resulting in a smoothie-like beverage. A reduction greater than 5 log10 CFU/mL was obtained for molds, yeasts, aerobic mesophilic, and coliforms for all the treatments. The shelf life of smoothies based on nutritional and sensorial quality was extended up to 90 days at refrigeration temperature.

Kinetic model of Clostridium beijerinckii's Acetone-Butanol-Ethanol fermentation considering metabolically diverse cell types.

Clostridium beijerinckii population branches into metabolically diverse cell types in batch cultures. Here, we present a new kinetic model of C. beijerinckii's Acetone-Butanol-Ethanol fermentation that considers three cell types: producers of acids (acidogenic), consumer of acids and producers of solvents (solventogenic), and spores cells. The model accurately recapitulates batch culture data. Also, the model estimates cell type-specific kinetic parameters, which can be helpful to improve the operation of the ABE fermentation and give a framework to study acidogenic and solventogenic metabolic pathways. To exemplify the latter, we used a constraint-based model to study how the ABE pathways are used among acidogenic and solventogenic cell types. We found that among both cell types, glycolytic production of ATP and consumption of NAD+ varies widely during the fermentation, with their maximum production/consumption rates happening when acidogenic and solventogenic growth rates were at their highest. However, acidogenic cells use the ABE pathway to contribute with an extra 12.5% of the total production of ATP, whereas solventogenic cell types use the ABE pathway to supply more than 75% of the demand for NAD+, alternating between the production of lactate and butyrate, being both coupled to the production of NAD+.

Optimization of an Extraction Process to Obtain a Food-Grade Sulforaphane-Rich Extract from Broccoli (Brassica oleracea var. italica).

Sulforaphane (SFN) is a powerful health-promoting compound found in broccoli in the form of its inactive precursor, glucoraphanin (GFN). SFN formation occurs through the enzymatic hydrolysis of glucoraphanin by myrosinase under specific chemical conditions. Its incorporation in food formulations has been hindered by the thermal instability of SFN and low concentration in Brassicaceae. Then, extracting SFN from broccoli at a temperature below 40 °C appears as an option to recover and stabilize SFN, aiming at delivering it as a nutraceutical. We studied an eco-friendly extraction process to obtain an SFN-rich extract from broccoli. The effect of the broccoli mass/solvent ratio, ethanol concentration in the extractant solution, and extraction time on the recovery of SFN, GFN, phenolic compounds, and antioxidant activity were studied through a Box-Behnken design. The regression models explained more than 70% of the variability in the responses, adequately representing the system. The experimental factors differently affected the bioactive compound recovery and antioxidant activity of the extracts. The extraction conditions that allowed the highest recovery of bioactive compounds and antioxidant activity were identified and experimentally validated. The results may provide the basis for the design of a process to produce a sulforaphane-rich food supplement or nutraceutical by using a GRAS extractant.

Effect of Drum-Drying Conditions on the Content of Bioactive Compounds of Broccoli Pulp.

This work studied the effect of drum-rotation frequency, drum temperature, and water-to-pulp ratio in a double-drum drier on the content of sulforaphane, glucoraphanin, total phenolic compounds, ascorbic acid, and antioxidant activity of broccoli pulp through a multilevel factorial design with one replicate. Drum-drying conditions did not significantly affect sulforaphane content, unlike glucoraphanin, however the poor adherence of broccoli pulp resulted in a final product with undefined shape and heterogeneous color. On the other hand, antioxidant activity was unevenly affected by drying conditions; however, drum-rotation frequency affected it in the same way that phenolic compounds and ascorbic acid, showing a concordant behavior. The ascorbic acid content decreased significantly after drying, and it was highly dependent on the experimental factors, resulting in a regression model that explained 90% of its variability. Drum-rotation frequency of 5 Hz, drum temperature of 125 °C, and water-to-pulp ratio of 0.25 resulted in an apparent increase of sulforaphane and phenolic compounds content of 13.7% and 47.6%, respectively. Drum drying has great potential to fabricate dehydrated broccoli-based foods with functional properties. Besides, since drum drying has low investment and operation costs, it represents a very attractive option for the industrialization of broccoli derivatives.

Clostridium strain selection for co-culture with Bacillus subtilis for butanol production from agave hydrolysates.

In this work, three Clostridium strains were tested for butanol production from Agave lechuguilla hydrolysates to select one for co-culturing. The agave hydrolysates medium was supplemented with nutrients and reducing agents to promote anaerobiosis. Clostridium acetobutylicum ATCC 824 had the highest butanol production (6.04 g/L) and was selected for further analyses. In the co-culture process, Bacillus subtilis CDBB 555 was used to deplete oxygen and achieve anaerobic conditions required for butanol production. The co-culture was prepared with C. acetobutylicum and B. subtilis without anaerobic pretreatment. Butanol production in co-culture from agave hydrolysates was compared with experiments using synthetic medium with glucose and a pure culture of C. acetobutylicum. The maximum butanol concentration obtained was 8.28 g/L in the co-cultured hydrolysate medium. Results obtained in the present work demonstrated that agave hydrolysates have the potential for butanol production using a co-culture of B. subtilis and C. acetobutylicum without anaerobic pretreatment.

Optimization of silver nanoparticle synthesis by chemical reduction and evaluation of its antimicrobial and toxic activity.

BACKGROUND: Chemical reduction has become an accessible and useful alternative to obtain silver nanoparticles (AgNPs). However, its toxicity capacity depends on multiple variables that generate differences in the ability to inhibit the growth of microorganisms. Thus, optimazing parameters for the synthesis of AgNPs can increase its antimicrobial capacity by improving its physical-chemical properties. METHODS: In this study a Face Centered Central Composite Design (FCCCD) was carried out with four parameters: A g N O 3 concentration, sodium citrate (TSC) concentration, N a B H 4 concentration and the pH of the reaction with the objective of inhibit the growth of microorganisms. The response variables were the average size of AgNPs, the peak with the greatest intensity in the size distribution, the polydispersity of the nanoparticle size and the yield of the process. AgNPs obtained from the optimization were characterized physically and chemically. The antimicrobial activity of optimized AgNPs was evaluated against Staphylococcus aureus, Escherichia coli, Escherichia coli AmpC resistant, and Candida albicans and compared with AgNPs before optimization. In addition, the cytotoxicity of the optimized AgNPs was evaluated by the colorimetric assay MTT (3- (4,5- Dimethylthiazol- 2- yl)- 2, 5 - Diphenyltetrazolium Bromide). RESULTS: It was found that the four factors studied were significant for the response variables, and a significant model (p < 0.05) was obtained for each variable. The optimal conditions were 8 for pH and 0.01 M, 0.0 6M, 0.01 M for the concentration of TSC, A g N O 3, and N a B H 4, respectively. Optimized AgNPs spherical and hemispherical were obtained, and 67.66% of it had a diameter less than 10.30 nm. A minimum bactericidal concentration (MBC) and minimum fungicidal Concentration (MFC) of optimized AgNPs was found against Staphylococcus aureus, Escherichia coli, Escherichia coli AmpC resistant, and Candida albicans at 19.89, 9.94, 9.94, 2.08 µg/mL, respectively. Furthermore, the lethal concentration 50 (L C 50) of optimized AgNPs was found on 19.11 µg/mL and 19.60 µg/mL to Vero and NiH3T3 cells, respectively. CONCLUSIONS: It was found that the factors studied were significant for the variable responses and the optimization process used was effective to improve the antimicrobial activity of the AgNPs.

Estrategias no farmacológicas en el paciente clínicamente enfermo, ¿qué nos dice la literatura? / Non-pharmacological Strategies in the Clinically Ill Patient, What does the Literature Tell Us?

En el paciente médicamente enfermo, las intervenciones farmacológicas o psicoterapéuticas habituales caen en desuso por particularidades propias de la hospitalización y la comorbilidad física; por ello se hace necesario identificar diferentes estrategias que permitan incidir benéficamente en la calidad de vida de este grupo de pacientes. Objetivo: Realizar una revisión narrativa de la literatura que permita identificar estrategias terapéuticas que hayan demostrado efectividad en el proceso de este grupo de pacientes. Metodología: Revisión narrativa de literatura. Resultados: Se identificaron 10 comentes terapéuticas no farmacológicas que han demostrado mejoría en indicadores como percepción de dolor, mejoría en calidad de vida, regulación de alteraciones del patrón de sueño, fatiga, en el contexto de pacientes con enfermedad crónica, que puede encontrarse en entornos tan diversos como son los pacientes de oncología o de las unidades de dolor crónico. Conclusiones: Las intervenciones no farmacológicas han demostrado efectividad en el control de síntomas físicos y emocionales en pacientes con enfermedad crónica y son herramientas con las que debe contar el profesional en salud mental.

For the treatment of the dinically ill patient the usual pharmacological interventíons have limited the use of non'pharmacological approach, due to particular factors such as hospitalization itself, physical comorbidities or reduced strategies for the therapeutic team; it ¿s necessary to identify therapeutical strategies that allow a positiva effect in the quality of life of this group of patients. Objective: lo realice a narrative review of literatura that allows us to identify therapeutically strategies that have proven dectivity in the dinically ill patient. Methods: Narrative review of literature. Results: There have been identined 10 non pharmacological therapeutic options that have demonstrated a positive effect in domains such as pain perception, quality of life perception, ¿nsomnia, fatigue, in the context of chronic and dinically ill patients in Services such as oncology or chronic pain. Condusions: Non-pharmacological interventíons have proven effectivity in ameliorate physical and emotional symptoms in patients with chronic diseases, and are useful tools for the mental health specialist.

In silico analysis of Clostridium acetobutylicum ATCC 824 metabolic response to an external electron supply.

The biological production of butanol has become an important research field and thanks to genome sequencing and annotation; genome-scale metabolic reconstructions have been developed for several Clostridium species. This work makes use of the iCAC490 model of Clostridium acetobutylicum ATCC 824 to analyze its metabolic capabilities and response to an external electron supply through a constraint-based approach using the Constraint-Based Reconstruction Analysis Toolbox. Several analyses were conducted, which included sensitivity, production envelope, and phenotypic phase planes. The model showed that the use of an external electron supply, which acts as co-reducing agent along with glucose-derived reducing power (electrofermentation), results in an increase in the butanol-specific productivity. However, a proportional increase in the butyrate uptake flux is required. Besides, the uptake of external butyrate leads to the coupling of butanol production and growth, which coincides with results reported in literature. Phenotypic phase planes showed that the reducing capacity becomes more limiting for growth at high butyrate uptake fluxes. An electron uptake flux allows the metabolism to reach the growth optimality line. Although the maximum butanol flux does not coincide with the growth optimality line, a butyrate uptake combined with an electron uptake flux would result in an increased butanol volumetric productivity, being a potential strategy to optimize the production of butanol by C. acetobutylicum ATCC 824.

Techno-economic analysis of bioethanol production from lignocellulosic residues in Colombia: a process simulation approach.

In this study a techno-economic analysis of the production of bioethanol from four lignocellusic (Sugarcane bagasse, Coffee cut-stems, Rice Husk, and Empty Fruit Bunches) residues is presented for the Colombian case. The ethanol production was evaluated using Aspen Plus and Aspen Process Economic Analyzer carrying out the simulation and the economic evaluation, respectively. Simulations included the composition of lignocellulosic residues, which was determined experimentally. It was found that empty fruit bunches presents the highest ethanol yield from a dry basis point of view (313.83 L/t), while rice husk produced less ethanol (250.56 L/t). The ethanol production cost was assessed for the standalone ethanol plant and the ethanol plant coupled with a cogeneration system. Moreover, ethanol production cost using EFB was the lowest with (0.49 US$/L) and without (0.58 US$/L) cogeneration scheme.

Process design and sustainability in the production of bioethanol from lignocellulosic materials

Background: Bioethanol is produced mainly from sugar cane and corn. In the last years it has been subject of debate due to the effects in food prices and land use change. The use of lignocellulosic materials for bioethanol production, such as agroindustry, forestry and municipal residues, wood or dendroenergetic species, has been proposed as a sustainable way for producing this biofuel. The design of a sustainable process for producing bioethanol requires a methodological approach whereby economical, environmental and social criteria are systematically integrated from the early stages of process design. Results: Until now a methodology for guiding the design of a sustainable process for bioethanol production is not available, and there are just a few studies on this subject. Moreover, with the recent global concerns on climate change, developed technologies have been confronted with additional requirements to validate their sustainability. In this sense, the inclusion of sustainability criteria on process design becomes necessary for defining a systematic methodology to select the most appropriate operations in the process stages to achieve a sustainable bioethanol production. Conclusions: A description of the stages for the production of bioethanol from lignocellulosic materials is provided in this review and the main findings in relation to the more important sustainability indicators are presented.