Muffin-Type Bakery Product Based on Mexican Mesquite (Prosopis spp.) Flour: Texture Profile, Acceptability, and Physicochemical Properties.

In this research, muffin-type bakery products were developed based on wheat flour (WF) and mesquite flour (MF) in the following proportions: WFMF 90:10, WFMF 75:25, and WFMF 50:50. The products were characterized based on various properties in which it was possible to observe that the water activity (aw) did not show a significant change with the increase in the concentration of MF. In addition, the increase in the concentration of MF modified the sensory properties (color, odor, flavor, texture, and acceptance), further decreasing the luminosity and increasing the values of the a* and b* coordinates. Moreover, in the texture profile analysis, it was found that the increase in the MF concentration increased hardness, fracturability, and gumminess and decreased adhesiveness and cohesiveness. All the previously mentioned changes were more evident in the WFMF50:50 and, to a lesser degree, in WFMF75:25. In general, in most evaluations realized, the WFMF90:10 treatment was the most similar to the control (without MF). However, WFMMF75:25 provided a higher protein and fiber content and a lower fat content. Finally, it is possible to use the flour obtained from the mesquite fruit to make bakery products since it is an important source of food due to the wide distribution of mesquite in the country.

Production and Characterization of Biocomposite Films of Bacterial Cellulose from Kombucha and Coated with Chitosan.

The purpose of this research is to produce and characterize bacterial cellulose (BC) films coated with chitosan (BC-CH). BC films were produced in a fermentation medium based on Camellia sinensis tea and dextrose (12 days at 25 °C) and subsequently treated with coating-forming solutions (CFSs) based on chitosan (BC-CH 0.5%, BC-CH 1.0%, and BC-CH 1.5%). As a result, the FTIR spectra of BC and BC-CH 1.5% showed the main characteristic bands of cellulose and chitosan. In the physicochemical characterization of the films, it was found that the incorporation of the chitosan coatings did not affect the thickness; however, it decreased the luminosity (L*) and increased redness (a*), yellowness (b*), and opacity (75.24%). Additionally, the light absorption properties in the UV-Vis range were improved. Furthermore, the application of the CFSs increased: the solubility (64.91%), the antimicrobial activity against S. aureus (6.55 mm) and E. coli (8.25 mm), as well as the antioxidant activity (57.71% and 24.57% free radical scavenging activity), and the content of total phenols (2.45 mg GAE/g). Finally, our results suggest that the BC-CH films developed in the present study show a potential application as active packaging material for food.

Retinal vasculitis associated with epstein-barr virus infection in a young immunocompetent patient. first colombian case report

RESUMEN Introducción. La infección por virus de Epstein-Barr (VEB) suele ser asintomática y persiste durante toda la vida. La afectación ocular es infrecuente, y aunque existen informes de casos, ninguno de ellos proviene de Colombia o Latinoamérica. Presentación del caso. Paciente masculino inmunocompetente con vasculitis retiniana unilateral generalizada, con vasos sin sangre temporales e inferonasales en la periferia, hemorragias intrarretinianas, vitritis intensa y desprendimiento de retina. La presencia de VEB se definió con una técnica de reacción en cadena de la poli-merasa en humor vítreo. El paciente recuperó la agudeza visual con el tratamiento oral antiviral convencional. Discusión. La afectación ocular asociada con el VEB se describe en pacientes inmunocomprometidos, en especial con infección por virus de inmunodeficiencia humana donde puede haber afectación retiniana. En este caso particular se discute la presencia de esta patología en pacientes inmunocompetentes. Conclusiones. La vasculitis retiniana es una entidad rara con mayor asociación a la inmuno-depresión. No existe un algoritmo de diagnóstico de esta enfermedad y la afectación ocular puede ser variable; tampoco existen líneas estándar de tratamiento. La evidencia reportada en el presente caso podría justificar estudios en pacientes seleccionados que muestran un compromiso de la agudeza visual sin una etiología establecida.

ABSTRACT Introduction: Epstein - Barr virus (EBV) infection is usually asymptomatic and persists throughout life. Eye involvement is rare, and even though there are some case reports, none of them comes from Colombia or Latin America. Case presentation: Immunocompetent young man with generalized unilateral retinal vasculitis, temporal and inferonasal bloodless vessels in the periphery, intraretinal hemorrhages, intense vitritis and retinal detachment. Epstein-Barr virus presence was determined using a polymerase chain reaction technique in vitreous humor. The patient recovered visual acuity with conventional antiviral oral treatment. Discussion: Eye involvement associated with Epstein-Barr virus is observed in immunocompromised patients, especially with HIV infection, where retinal involvement may occur. This case reports the presence of this pathology in an immunocompetent patient. Conclusions: Retinal vasculitis is a rare entity, frequently associated with immunocompromise. There is no diagnostic algorithm for this disease and eye involvement may be variable; there are no standard lines of treatment either. The evidence reported here explains the need for studies in selected patients showing visual acuity involvement without an established etiology.

Removal of chromium and lead by a sulfate-reducing consortium using peat moss as carbon source.

The effect of pre-treated peat moss on the ability of a sulfate-reducing microbial consortium to remove chromium and lead in solution was evaluated. The most active bacterial community (235.7 mmol H2S/g VSS) was selected from among eight consortia. The peat moss was pre-treated with different HCl concentrations and contact times. The best combination of treatments was 20% HCl for 10 min. The constant substrate affinity Ks was 740 mg COD/L and the ratio COD/SO4(2-) was 0.71. At pH 5, higher production of biogenic sulfide was observed. The up-flowpacked bed bioreactor operated at a flow of 8.3 mL/min for 180 h to obtain removal efficiency (by sulfate-reducing activity) of 90% lead and 65% chromium. It is important to consider that peat moss is a natural adsorbent that further influences the removal efficiency of metal ions.

Real-time monitoring of ligand-receptor interactions with fluorescence resonance energy transfer.

FRET is a process whereby energy is non-radiatively transferred from an excited donor molecule to a ground-state acceptor molecule through long-range dipole-dipole interactions. In the present sensing assay, we utilize an interesting property of PDA: blue-shift in the UV-Vis electronic absorption spectrum of PDA (Figure 1) after an analyte interacts with receptors attached to PDA. This shift in the PDA absorption spectrum provides changes in the spectral overlap (J) between PDA (acceptor) and rhodamine (donor) that leads to changes in the FRET efficiency. Thus, the interactions between analyte (ligand) and receptors are detected through FRET between donor fluorophores and PDA. In particular, we show the sensing of a model protein molecule streptavidin. We also demonstrate the covalent-binding of bovine serum albumin (BSA) to the liposome surface with FRET mechanism. These interactions between the bilayer liposomes and protein molecules can be sensed in real-time. The proposed method is a general method for sensing small chemical and large biochemical molecules. Since fluorescence is intrinsically more sensitive than colorimetry, the detection limit of the assay can be in sub-nanomolar range or lower. Further, PDA can act as a universal acceptor in FRET, which means that multiple sensors can be developed with PDA (acceptor) functionalized with donors and different receptors attached on the surface of PDA liposomes.

Differential utilization of T cell receptor TCR alpha/TCR delta locus variable region gene segments is mediated by accessibility.

T cell receptor (TCR) variable region exons are assembled from germline V, (D), and J gene segments, each of which is flanked by recombination signal (RS) sequences that are composed of a conserved heptamer, a spacer of 12 or 23 bp, and a characteristic nonamer. V(D)J recombination only occurs between V, D, and J segments flanked by RS sequences that contain, respectively, 12(12-RS)- and 23(23-RS)-bp spacers (12/23 rule). Additional mechanisms can restrict joining of 12/23 RS matched segments beyond the 12/23 rule (B12/23). The TCRdelta locus is contained within the TCRalpha locus; TCRalpha variable region exons are encoded by TRAV and TRAJ segments and those of TCRdelta by TRDV, TRDD, and TRDJ segments. On the basis of the 12/23 rule, both TRAV and TRDV gene segments are compatible to rearrange with TRDD gene segments; however, TRAV-to-TRDD joins are not observed in vivo. Absence of TRAV-to-TRDD rearrangement might be explained either by B12/23 restriction or by differential accessibility of the TRDV versus TRAV gene segments for rearrangement to TRDD. We used in vitro substrate analysis to reveal that both TRAV and TRDV 23-RSs mediate rearrangements to the 5'TRDD1 12-RS, demonstrating that B12/23 restriction does not explain these rearrangement biases. However, targeted replacement of TRDD1 and its 12-RSs with TRAJ38 and its 12-RS showed that TRDV gene segments rearrange with the ectopic TRAJ38, whereas TRAV segments do not. Our results demonstrate that sorting of TRAV and TRDV gene segments is determined by differential locus accessibility during T cell development.

Expression of cholera toxin epitopes inserted in flagellin by attenuated Salmonella strains

A novel antigen expression system has recently been developed by means of bacterial flagella, which are potent immunogens (Newton et al., Science 244:70-72,1989). Here we show the insertion of two epitopes from the cholera toxin B-subunit in Salmonella flagelin, CTP-1 (residues 8-20) and CTP-3 (residues 50-64) (Jacob et al., Proc. Natl Acad. Sci. USA 81: 7893-7896, 1984). First, we inserted CTP-1 for expression as a flagellar fusion; a hybrid flagellin expressing CTP-1 and CTP-3 in the hypervariable region of the flagellin gene was also constructed in an attempt to increase the cholera toxin neutralization potential, as well as to address some practical questions concerning the flagellar antigen expression system. The resulting constructs were non-motile although expression of chimeric flagellin was detected by immunoblotting and electron microscopy. One of the constructs (CTP-l + CTP-3) severely affected flagellin expression.