Biologically synthesized silver nanoparticles as potent antibacterial effective against multidrug-resistant Pseudomonas aeruginosa.

Pseudomonas aeruginosa is one of the most worrisome infectious bacteria due to its intrinsic and acquired resistance against several antibiotics and the recalcitrance of its infections; hence, the development of novel antimicrobials effective against multidrug-resistant P. aeruginosa is mandatory. In this work, silver nanoparticles obtained by green synthesis using a leaf extract and fungi were tested against a battery of clinical strains from cystic fibrosis, pneumonia and burnt patients, some of them with multidrug resistance. Both nanoparticles showed a potent antibacterial effect, causing severe damage to the cell wall, membrane and DNA, and inducing the production of reactive oxygen species. Moreover, the nanoparticles derived from fungi showed synergistic antibacterial effects with the antibiotics meropenem and levofloxacin for some clinical strains and both kinds of nanoparticles were nontoxic for larvae of the moth Galleria mellonella, encouraging further research for their implementation in the treatment of P. aeruginosa infections.

Association between serum calcium levels and the presentation of postpartum endometritis in housed dairy cows.

The present work aims to identify the minimum threshold of serum calcium (SC) values in cows during the first week postpartum and evaluate their relationship with the presentation of endometritis in housed dairy cows. In this prospective longitudinal observational study, 467 cows from 3 farms in Lima-Peru were studied. Blood samples were collected from cows during the first week postpartum. Endometritis was diagnosed on day 35 ± 3 days postpartum by evaluation of vaginal discharge samples. The samples were obtained using the MetricheckTM device (Simcro, New Zealand). Two cut-off points were used to diagnose endometritis: a) endometritis metricheck score ≥ 3, and b) endometritis metricheck score ≥ 2. In the univariate model that considers a SC threshold of 5.25 to 8.75 mg/dL (1.31 to 2.18 mmol/L), a significant relationship (p < 0.05) was found for endometritis metricheck score ≥ 3, while no significant relationship was found (p = 0.12) with endometritis metricheck score ≥ 2. In both cases, the optimal SC threshold for the appearance of endometritis was determined to be a value ≥7.0 mg/dL (≥1.75 mmol/L). In the logistic regression models (parity, calving season, calcium level, and their interaction), only two variables were retained, parity and calcium level (p < 0.10). It was found that the probability of having endometritis metricheck score ≥ 3 was 1.9 (95% CI: 1.1 to 3.1), whereas the probability of having endometritis metricheck score ≥ 2 was 1.5 (95% CI: 1.0 to 2.5) in cows with calcium levels <7.0 mg/dL (<1.75 mmol/L). In conclusion, cows with calcium levels <7.0 mg/dL (<1.75 mmol/L) have a 1.9-fold greater risk of developing endometritis metricheck score ≥ 3 in the first week postpartum.

Influence of minimally invasive endodontic access cavities on root canal shaping and filling ability, pulp chamber cleaning and fracture resistance of extracted human mandibular incisors.

AIM: To evaluate the influence of the location and design of endodontic access cavities on root canal shaping and filling ability, pulp chamber cleaning and fracture resistance of extracted human mandibular incisors. METHODOLOGY: After pre-selection using periapical radiographs, forty extracted intact human mandibular incisors were scanned in a micro-computed tomographic device. The teeth were matched based on similar anatomical features of the canals and assigned to four experimental groups (n = 10) according to the endodontic access cavity and root canal preparation protocol: traditional/TRUShape (T/TRU); traditional/MTwo (T/MT); minimally invasive/TRUShape (MI/TRU); and minimally invasive/MTwo (MI/MT). The samples were scanned after root canal instrumentation and filling procedures. The parameters evaluated were as follows: volume and area of the root canal, noninstrumented canal areas, canal transportation and centring ratio, accumulated hard tissue debris, voids in root canal fillings and remnants of root canal filling materials in the pulp chamber. After root canal filling and cavity restoration procedures, the samples were submitted to a fracture resistance test. Data were statistically analysed using Shapiro-Wilk, one-way anova and Bonferroni tests with a significance level of 5% (α = 0.05). RESULTS: There was no difference regarding all parameters evaluated before and after root canal preparation (volume and area of the root canal, noninstrumented canal areas, canal transportation and centring ratio, and accumulated hard tissue debris) amongst the groups (P > 0.05). MI/TRU and MI/MT groups were associated with significantly more voids in root canal fillings when compared to the T/TRU and T/MT groups (P < 0.05). Percentage of root canal filling material remnants in the pulp chamber after cleaning procedures and mean fracture resistance values were not significantly different amongst the four experimental groups (P > 0.05). CONCLUSIONS: The location and design of the endodontic access cavity did not impact on root canal preparation nor resistance to fracture of extracted mandibular incisors, regardless of the instrument used. Minimally invasive access cavities were associated with significantly more voids in root canal fillings.

Trichoderma virens Gl006 and Bacillus velezensis Bs006: a compatible interaction controlling Fusarium wilt of cape gooseberry.

The combination of Trichoderma virens Gl006 and B. velezensis Bs006 as a consortium has high potential to control Fusarium wilt (FW) of cape gooseberry (Physalis peruviana) caused by Fusarium oxysporum f. sp. physali (Foph). However, the interactions between these two microorganisms that influence the biocontrol activity as a consortium have not been studied. Here, we studied the interactions between Gl006 and Bs006 that keep their compatibility under in vitro and greenhouse conditions. Antagonism tests between Gl006 and Bs006 inoculated both individually and in consortium against Foph strain Map5 was carried out on several solid media. The effect of supernatant of each selected microorganism on growth, conidia germination, biofilm formation and antagonistic activity on its partner was also studied. Biocontrol activity by different combinations of cells and supernatants from both microorganisms against Fusarium wilt was evaluated under greenhouse conditions. In vitro antagonism of the consortium against Foph showed a differential response among culture media and showed compatibility among BCA under nutritional conditions close to those of the rhizosphere. The supernatant of Bs006 did not affect the antagonistic activity of Gl006 and vice versa. However, the supernatant of Bs006 promoted the biocontrol activity of Gl006 in a synergistic way under greenhouse, reducing the disease severity by 71%. These results prove the compatibility between T. virens Gl006 and B. velezensis Bs006 as a potential tool to control Fusarium wilt of cape gooseberry.

Effects of several storage media on viability and proliferation capacity of periodontal ligament cells.

AIM: The purpose of this study was to investigate the effect of different storage media on viability and proliferation capacity of periodontal ligament cells. METHODS: Plates with periodontal ligament fibroblasts (PDLF) cells were incubated in skimmed and whole milk, recently prepared Hank's balanced salt solution (HBSS), Save-A-Tooth system's, coconut water, propylene glycol with 20% propolis, egg white, tap water (negative control) at 5 °C and 20 °C, for 24 h. In one of the plates of each temperature, cell viability was determined by MTT assay. In the remaining plates, the wells were filled and incubated with Minimum Essential Medium (MEM) at 37 °C for 24, 48, 72, 96, and 120 h. The proliferation capacity of PDFL cells was also evaluated by MTT assay. Data were statistically analyzed by Kruskal-Wallis, Scheffé and Mann-Whitney tests (α = 5%). RESULTS: At 5 °C, milk maintained more viable cells than other storage media immediately after exposure (0 h) and allowed greater proliferation capacity. At 20 °C, milk and HBSS had similar and allowed similar proliferation ability at 24 and 48 h. From 72 h onwards, capacity to maintain cell viability the proliferation rate of cells incubated in HBSS was superior than milk. At both temperature and experiments, Save-A-Tooth system was similar to tap water. CONCLUSION: Milk and HBSS were more effective in maintaining cellular viability and proliferation capacity than any other storage media. At 5 °C, the most viable alternative was milk. At 20 °C, HBSS had better results.

Cementum protein 1 transfection does not lead to ultrastructural changes in nucleolar organization of human gingival fibroblasts.

BACKGROUND AND OBJECTIVE: Transfection of cementum protein 1 (CEMP1) into human gingival fibroblasts (HGFs) notably increases cell metabolism and results in overexpression of molecules related to biomineralization at transcriptional and protein levels. Therefore, HGF-CEMP1 cells are considered as putative cementoblasts. This represents a significant advance in periodontal research because cementum neoformation is a key event in periodontal regeneration. In addition, it is well known that important changes in cell metabolism and protein expression are related to nucleolar structure and the function of this organelle, which is implicated in ribosome biogenesis. The aim of this study was to determine the effect of transfecting CEMP1 gene in human HGF on the ultrastructure of the nucleolus. MATERIAL AND METHODS: Cells were processed using the conventional technique for transmission electron microscopy, fixed with glutaraldehyde, postfixed with osmium tetraoxide, and embedded in epoxy resin. Semi-thin sections were stained with Toluidine blue and observed by light microscopy. Thin sections were stained with uranyl acetate and lead citrate. For ribonucleoprotein detection, the staining method based on the regressive effect of EDTA was used. In addition, the osmium ammine technique was used for specific staining of DNA. RESULTS: The results obtained in this study suggest that transfection of CEMP1 into HGFs does not produce changes in the general nucleolar ultrastructure because the different components of the organelle are present as fibrillary centers, and dense fibrillar and granular components compared with the control. CONCLUSION: The transfection of CEMP1 into HGFs allows these cells to perform cementoblast-like functions without alteration of the ultrastructure of the nucleolus, evaluated by the presence of the different compartments of this organelle involved in ribosomal biogenesis.

Additively manufactured MEMS multiplexed coaxial electrospray sources for high-throughput, uniform generation of core-shell microparticles.

This study reports the first MEMS multiplexed coaxial electrospray sources in the literature. Coaxial electrospraying is a microencapsulation technology based on electrohydrodynamic jetting of two immiscible liquids, which allows precise control with low size variation of the geometry of the core-shell particles it generates, which is of great importance in numerous biomedical and engineering applications, e.g., drug delivery and self-healing composites. By implementing monolithic planar arrays of miniaturized coaxial electrospray emitters that work uniformly in parallel, the throughput of the compound microdroplet source is greatly increased, making the microencapsulation technology compatible with low-cost commercial applications. Miniaturized core-shell particle generators with up to 25 coaxial electrospray emitters (25 emitters cm-2) were fabricated via stereolithography, which is an additive manufacturing process that can create complex microfluidic devices at a small fraction of the cost per device and fabrication time associated with silicon-based counterparts. The characterization of devices with the same emitter structure but different array sizes demonstrates uniform array operation. Moreover, the data demonstrate that the per-emitter current is approximately proportional to the square root of the flow rate of the driving liquid, and it is independent of the flow rate of the driven liquid, as predicted by the theory. The core/shell diameters and the size distribution of the generated compound microparticles can be modulated by controlling the flow rates fed to the emitters.

MANUAL PARA LA GESTIÓN DEL MANTENIMIENTO CORRECTIVO DE EQUIPOS BIOMÉDICOS EN LA FUNDACIÓN VALLE DEL LILI / MANUAL FOR THE MANAGEMENT OF CORRECTIVE MAINTENANCE OF BIOMEDICAL EQUIPMENT IN FUNDACIÓN VALLE DEL LILI / MANUAL DE GESTÃO DA MANUTENÇÃO CORRETIVA DE EQUIPAMENTOS BIOMÉDICOS NA FUNDAÇÃO VALLE DEL LILI

El mantenimiento correctivo está orientado a corregir los defectos observados en los equipamientos o instalaciones, localizando las averías y reparándolas. Los costos de reparación de un equipo suelen ser mucho mayores en la etapa correctiva que en la etapa preventiva, y la literatura existente está orientada más hacia la prevención que hacia la corrección. Sin embargo, es inevitable que en una institución hospitalaria, como en cualquier otra, se presenten frecuentemente problemas en los equipos que no pudieron ser previstos o evitados mediante el mantenimiento preventivo o correctivo. Por esta razón, se hace necesario contar con protocolos para el mantenimiento correctivo que contengan criterios y procesos claramente definidos para mejorar la eficiencia y la eficacia en la solución de los problemas y que permitan la máxima disponibilidad en la prestación de los servicios. En este trabajo se presenta, como caso de estudio, el desarrollo e implementación de un Manual para la Gestión del Mantenimiento Correctivo en una de las clínicas de más alto nivel en la ciudad de Cali: La Fundación Valle del Lili.

The corrective maintenance is aimed at correcting the shortcomings in the equipment or facilities, locating faults and repairing them. Repair costs of equipment are usually much higher in the corrective stage than in the preventive stage, and the existing literature is oriented more towards prevention than correction. However, it is inevitable that in a hospital, as elsewhere, problems are often present on computers that could not be foreseen or avoided through preventive or corrective maintenance. For this reason corrective maintenance protocols containing clearly defined criteria and processes to improve efficiency and effectiveness in solving problems and ensuring maximum availability in the provision of services, are needed. This paper presents a case study, development and implementation of a Management Manual for corrective maintenance of the highest level clinics in the city of Cali: The Fundación Valle del Lili.

A Manutenção corretiva visa corrigir as deficiências do equipamento ou instalações, localizando falhas e reparálas. Os Custos de reparação de equipamento são geralmente muito maior na fase corretiva que na fase preventiva, e a literatura existente é mais orientada para a prevenção que para a correção. No entanto, é inevitável que em um hospital, como em outros lugares, muitas vezes se apresentam problemas nos equipamentos que não podiam ser previstos ou evitados através da manutenção preventiva ou corretiva. Por esta razão, é necessário ter protocolos de manutenção corretiva que contenham critérios e processos claramente definidos para melhorar a eficiência e eficácia na resolução de problemas e para assegurar a máxima disponibilidade na prestação de serviços. Este trabalho se apresenta como um caso de estudo, o desenvolvimento e a implementação de um Manual de Gestão para manutenção corretiva das clínicas de maior nível na cidade de Cali: a Fundação Valle del Lili.

Note: Limitations of the optoelectronic control for carbon nanoparticles synthesis via arc-discharge in solution.

Submerged electric arc discharge in liquids has shown to be a promising method for synthesizing a wide variety of nanomaterials. However, it requires an accurate current stability control to ensure the desired purity and structure of the products. The discharge stability control through light emission has been previously studied, but still requires further investigation to clarify the influence of some parameters. The present work has studied the solution's transmittance variation over time, the correlation between the arc light emission and the arc current, and the feasibility of controlling the arc current by using a specific wavelength of the arc light spectrum. Several limitations of the optoelectronic control were found at low currents (I < 50 A).

Crohn's disease susceptibility variants in Colombian tuberculosis patients.

BACKGROUND: The molecular basis of genetic predisposition to pulmonary tuberculosis (PTB) in adults remains largely elusive. A chronic granulomatous inflammatory reaction is one of the main characteristics of the immune response to TB; however, a similar reaction is observed in other diseases, such as Crohn's disease. OBJECTIVE: To assess the association of genetic polymorphisms previously associated with Crohn's disease and PTB in a Colombian population of PTB patients and controls. DESIGN: A case-control study was performed among 500 newly diagnosed PTB patients and 320 healthy control subjects. Thirty-one single nucleotide polymorphisms (SNPs) identified in a previous meta-analysis of genome-wide association studies of Crohn's disease were used for genotyping using MassARRAY technology. RESULTS: In this study, we identified an association with borderline significance (P = 0.0009433 and P = 0.029 after multiple testing by Bonferroni's correction) of SNP rs10995271 with PTB. SNP rs10995271 is in linkage disequilibrium with SNPs belonging to the zinc finger protein (ZNF365) gene. CONCLUSIONS: Our results suggest that human PTB shares a genetic basis with Crohn's disease, and that SNPs in the ZNF365 gene would have a role in the occurrence of chronic granulomatous inflammatory reaction in TB as well as Crohn's disease.

Evaluation of Toll-like receptor and adaptor molecule polymorphisms for susceptibility to tuberculosis in a Colombian population.

Immunological studies have supported the idea that innate immunity is critical for the control of Mycobacterium tuberculosis (Mtb) infection in humans. Despite the overwhelming evidence showing the critical role of Toll-like receptors (TLRs) in the in vitro recognition of Mtb, the in vivo significance of individual TLRs has been more difficult to demonstrate consistently. We were interested in examining the role of genes of TLRs and molecules involved in their signalling cascades, and a case-control study was designed to test the association of polymorphisms of these innate immune genes with pulmonary tuberculosis (TB) in a Colombian population. In this study, we did not find an association with TLR2, TLR4, TLR9, MyD88 or MAL/TIRAP polymorphic variants. These findings suggest that those genes are not involved as risk factors for pulmonary TB in our population.

Oocyte structure and ultrastructure in the Mexican silverside fish Chirostoma humboldtianum (Atheriniforme: Atherinopsidae)

The structural and ultrastructural features of gonads from endemic Mexican fish have received scarce attention. This study describes the histological and ultrastructural characteristics of oocyte from Chirostoma humboldtianum. The ovary is asynchronic, and as such, most phases of oocyte development are found in the same ovary. The complete process of oogenesis was divided in five stages: oogonium and folliculogenesis, primary growth, cortical alveoli and lipid inclusions, vitellogenesis, and maturation. The presence of big filaments, which appear at the end of primary growth, induces some common follicular adaptation. During primary growth, abundant ribosomes, the rough endoplasmic reticulum, and mitochondria are grouped in the cytoplasm. At the end of this stage, the Z1 layer of the chorion is developed, while microvilli start to be evident. In the cortical alveoli and lipid droplets phase, intense PAS positive vesicles, some of them containing nucleoid material, are observed in the peripheral cytoplasm and the lipid droplets take a more central position. In vitellogenesis, the proteic yolk accumulates in a centripetal way while the chorion is completely formed. During maturation, the germinal vesicle migrates to the animal pole, meiosis is restored, and there is nuclear breakdown. The oocyte increases its size and holds some oil droplets and a big fluid mass of yolk. On the outside, filaments completely surround the oocyte. Rev. Biol. Trop. 56 (3): 1371-1380. Epub 2008 September 30.

Human spleen contains different subsets of dendritic cells and regulatory T lymphocytes.

Most knowledge about dendritic cells (DCs) and regulatory T cells in humans has been gathered from circulating cells but little is known about their frequency and distribution in lymphoid organs. This report shows the frequency, phenotype and location of DCs and regulatory T cells in deceased organ donors' spleens. As determined by flow cytometry, conventional/myeloid DCs (cDCs) CD11c(high)HLA-DR(+)CD123(-/low) were 2.3 +/- 0.9% and LIN(-) HLA-DR(+)CD11c(high) 2.1 +/- 0.3% of total spleen cells. Mature CD11c(high)HLA-DR(+)CD83(+) were 1.5 +/- 0.8% and 1.0 +/- 1.6% immature CD11c(high)HLA-DR(+)CD83(-) cDC. There were 0.3 +/- 0.3% plasmacytoid DCs (pDC) CD11c(-/low)HLA-DR(+)CD123(high) and 0.3 +/- 0.1% LIN(-)HLA-DR(+)CD123(high). Cells expressing cDCs markers, BDCA-1 and BDCA-3, and pDCs markers BDCA-2 and BDCA-4 were observed in higher frequencies than DCs with other phenotypes evaluated. CD11c(+), CD123(+) and CD83(+) cells were located in subcapsular zone, T cells areas and B-cell follicles. CD4(+)CD25(high) Tregs were 0.2 +/- 0.2% and CD8(+)CD28(-) comprised 11.5 +/- 8.1% of spleen lymphocytes. FOXP3(+) cells were found in T- and B-cell areas. The improvement in cell separation, manipulation and expansion techniques, will facilitate the manipulation of donor spleen cells as a part of protocols for induction and maintenance of allograft tolerance or treatment of autoimmune diseases.

Oocyte structure and ultrastructure in the Mexican silverside fish Chirostoma humboldtianum (Atheriniforme: Atherinopsidae).

The structural and ultrastructural features of gonads from endemic Mexican fish have received scarce attention. This study describes the histological and ultrastructural characteristics of oocyte from Chirostoma humboldtianum. The ovary is asynchronic, and as such, most phases of oocyte development are found in the same ovary. The complete process of oogenesis was divided in five stages: oogonium and folliculogenesis, primary growth, cortical alveoli and lipid inclusions, vitellogenesis, and maturation. The presence of big filaments, which appear at the end of primary growth, induces some common follicular adaptation. During primary growth, abundant ribosomes, the rough endoplasmic reticulum, and mitochondria are grouped in the cytoplasm. At the end of this stage, the Z1 layer of the chorion is developed, while microvilli start to be evident. In the cortical alveoli and lipid droplets phase, intense PAS positive vesicles, some of them containing nucleoid material, are observed in the peripheral cytoplasm and the lipid droplets take a more central position. In vitellogenesis, the proteic yolk accumulates in a centripetal way while the chorion is completely formed. During maturation, the germinal vesicle migrates to the animal pole, meiosis is restored, and there is nuclear breakdown. The oocyte increases its size and holds some oil droplets and a big fluid mass of yolk. On the outside, filaments completely surround the oocyte.