Partial prevention of hepatic lipid alterations in nude mice by neonatal thymulin gene therapy

During adult life athymic (nude) male mice display not only a severe T-cell-related immunodeficiency but also endocrine imbalances and a moderate hyperglycemia. We studied the impact of congential athymia on hepatic lipid composition and also assessed the ability of neonatal thymulin gene therapy to prevent the effects of athymia. We constructed a recombinant adenoviral vector, RAd-metFTS, expression a synthetic DNA sequence encoding met-FTS, an analog of the thymic peptide facteur thymique sérique (FTS), whose Zn-bound biologically active form is known as thymulin. On postnatal day 1–2 homozygous (nu/nu) nude and heterozygous (nu/+) mice were injected with 10⁸ pfu of RAd-metFTS or RAd-βgal (control vector) intramuscularly. The animals were processed at 52 d of age. Serum thymulin, glycemia, hepatic phospholipid FA compostion and free and esterified cholesterol were determined. Adult homozygous male nudes were significantly (P<0.01) hyperglycemic when compared with their heterozygous counterparts (2.04 vs. 1.40 g/L, respectively). The relative percentage of 16∶0, 18∶1n−9, and 18∶1n−7 FA was lower, whereas that of 18∶0, 20∶4n−6, and 22∶6n−3 FA was higher, in hepatic phospholipid (PL) of nu/nu animals as compared with their nu/+ counterparts. Some of these alterations, such as that in the relative content of 22∶6n−3 in liver PL and the unsaturation index, were completely or partially prevented by neonatal thymulin gene therapy. We conclude that the thymus influences lipid metabolism and that thymulin is involved in this modulatory activity.     

Synthetic ligands able to interact with the p53 tetramerization domain. Towards understanding a protein surface recognition event

The applied interaction of synthetic molecules with defined regions of protein surfaces is an emerging strategy for the modulation of protein activity and/or stability. In spite of recent advances, the design of these molecules is not trivial. Among the most challenging aspects in designing these compounds is that they must compete with water molecules for interaction with polar patches of protein surfaces. Herein is reported the preparation of an arginine-rich peptide that interacts in aqueous solution with a very hydrophilic patch at the surface of the tetramerization domain of the tumor suppressor protein p53. The interaction has been studied by several complementary techniques. By using this peptide as a template, a library of peptides has been prepared and evaluated in order to examine the different factors that contribute to the recognition event. The conclusions extracted from this work could be useful for the design of ligands directed at highly hydrophilic protein surface patches.     

Scanning electron microscopy of Anisakis larvae following different treatments

Ingestion of fish parasitized with Anisakis larvae can produce infestation and/or allergy in consumers. Technological and food processing treatments have been applied to parasitized fish in order to kill the larvae and avoid the infestation; however, their influence on allergenicity has not been studied. Four lots of hake (Merluccius merluccius) steaks artificially parasitized with Anisakis larvae were subjected to two storage chilling (5 degrees C +/- 1 degrees C) and freezing (-20 degrees C +/- 1 degrees C) treatments and two food processing treatments of heat (final temperature 86.3 degrees C) and microwave (final temperature 66.9 degrees C) and studied by scanning electron microscopy, environmental scanning electron microscopy (ESEM) (acid [pH = 2] and water preparations), and emission of fluorescence. Anisakis larvae were resistant to acid conditions, remaining alive after treatment. Larvae in the heat- and microwave-treated lots presented coagulated and disrupted zones in the cuticle with release of fluids. The cylindrical shape changed to a dehydrated appearance mainly observed by ESEM. Fluorescence was only noticeable in the frozen larvae. Larvae without apparent changes, together with dehydrated ones, were observed by ESEM in the frozen lot; nevertheless, no disruptions in the cuticle were perceptible. Further studies are needed in order to elucidate if the changes observed in the cuticle reduce the resistance of the parasites to the action of gastric enzymes in the gastrointestinal tract and to determine the release of allergens to the flesh by the live larvae during chilled storage of the fish.     

Bio-nanocomposites by assembling of gelatin and layered perovskite mixed oxides

A new class of bio-nanocomposites based on hybrid gelatin-perovskite hydrogels was prepared by mixing exfoliated perovskite-tetraalkylammonium species in aqueous suspensions with gelatin solutions. Colloidal nanosheets derived from the CsCa2Nb3O10 layered perovskite re-stacked in the gelatin solutions give bio-nanocomposite materials with different content in the inorganic moiety. These films can be easily processed as homogeneous self-supported films. The partial exfoliation of the pristine mixed oxide is produced from alkylammonium exchanged phases, being the tetraalkylammonium ions (tetraethylammonium, TEA+) an efficient intermediate to give the colloid phase constituted by well exfoliated materials useful to generate homogeneous films. The nanosheets are highly oriented in the bio-nanocomposite films in agreement with the XRD patterns and the FTIR dichroism. This orientation could be considered as a characteristic of this type of hybrid materials leading to new potential applications. In this way, we have observed that the assembling of perovskite to gelatin produces a greater increase of the dielectric permittivity than the dielectric loss in the studied samples.     

Diffuse light propagation in a turbid medium with varying refractive index: Monte Carlo modeling in a spherically symmetrical geometry

We report on the development of Monte Carlo software that can model media with spatially varying scattering coefficient, absorption, and refractive index. The varying refractive index is implemented by calculating curved photon paths in the medium. The results of the numerical simulations are compared with analytical solutions obtained using the diffusion approximation. The model under investigation is a scattering medium that contains a spherically symmetrical inclusion (inhomogeneity) created by variation in optical properties and having no sharp boundaries. The following steady-state cases are considered: (a) a nonabsorbing medium with a spherically symmetrical varying refractive index, (b) an inclusion with varying absorption and scattering coefficients and constant refractive index, and (c) an inclusion with varying absorption, scattering, and refractive index. In the latter case it is shown that the interplay between the absorption coefficient and the refractive index may create the effect of a hidden inclusion.     

Mass Transfer Modelling During Osmotic Dehydration of Jumbo Squid (Dosidicus gigas): Influence of Temperature on Diffusion Coefficients and Kinetic Parameters

Mathematical modelling was used to study the effect of process temperature on moisture and salt mass transfer during osmotic dehydration (OD) of jumbo squid with 6% (w v ⁻¹) NaCl at 75, 85 and 95 °C. The diffusion coefficients for moisture and salt increased with temperature. Based on an Arrhenius-type equation, activation energy values of 62.45 kJ mol⁻¹ and 52.14 kJ mol⁻¹ for moisture and salt, respectively, were estimated. Simulations of mass transfer for both components were performed according to Newton, Henderson and Pabis, Page, Weibull and logarithmic mathematical expressions. The influence of drying temperature on the kinetic parameters was also studied. Based on statistical tests, the Weibull and logarithmic models were the most suitable to describe the mass transfer phenomena during OD of jumbo squid.     

Effect of high pressure treatments on smoked cod quality during refrigerated storage

The effect of high pressure (HP) treatments on microbiological, chemical, textural and sensory characteristics of vacuum-packaged cold-smoked cod refrigerated at 5 °C for 60 d was evaluated. HP at 400, 500 and 600 MPa for 5 and 10 min reduced microbial counts of smoked cod and delayed microbial growth during refrigerated storage. No differences in lipid oxidation estimated as thiobarbituric acid reactive substances (TBARS) were observed after pressurization and during refrigeration. Only tryptamine and spermine at very low levels were detected among biogenic amines in smoked cod. High pressure treatments induced a brighter appearance of smoked cod, with higher values of L∗ and b∗, whereas a∗ values decreased with pressurization. HP affected hardness and shear strength of smoked cod, with higher values after treatment, but differences with untreated smoked cod were attenuated during the storage period. No differences in overall appearance and odor of smoked cod were reported after sensory evaluation. The results obtained in the present work point to the usefulness of pressurization of smoked cod at 400 MPa for 10 min or 500 MPa for 5 min to obtain an acceptable product with extended shelf-life. HP might increase the safety and protect the product against possible pathogen contamination during processing.     

Cell Therapy for Colorectal Cancer: The Promise of Chimeric Antigen Receptor (CAR)-T Cells

Colorectal cancer (CRC) is a global public health problem as it is the third most prevalent and the second most lethal cancer worldwide. Major efforts are underway to understand its molecular pathways as well as to define the tumour-associated antigens (TAAs) and tumour-specific antigens (TSAs) or neoantigens, in order to develop an effective treatment. Cell therapies are currently gaining importance, and more specifically chimeric antigen receptor (CAR)-T cell therapy, in which genetically modified T cells are redirected against the tumour antigen of interest. This immunotherapy has emerged as one of the most promising advances in cancer treatment, having successfully demonstrated its efficacy in haematological malignancies. However, in solid tumours, such as colon cancer, it is proving difficult to achieve the same results due to the shortage of TSAs, on-target off-tumour effects, low CAR-T cell infiltration and the immunosuppressive microenvironment. To address these challenges in CRC, new approaches are proposed, including combined therapies, the regional administration of CAR-T cells and more complex CAR structures, among others. This review comprehensively summarises the current landscape of CAR-T cell therapy in CRC from the potential tumour targets to the preclinical studies and clinical trials, as well as the limitations and future perspectives of this novel antitumour strategy.     

Preparation and release profiles of cyclophosphamide from segmented polyurethanes

Supermolecular structure of drug delivery system on the basis of segmented polyurethane (SPU) has been determined to control the release of anticancer drug, cyclophosphamide (CPh). It has been established that the phase separation in SPU is essentially intensified by means of both the increase of molecular weight for SPU's soft segments and CPh incorporation in the monolithic systems of polyethylene glycol‐based polyurethane. Infrared and proton NMR data indicate that CPh is hydrogenicly associated with a urethane group of hard segments. It has been determined that the drug‐concentrated domains of hard segments are microheterogeneously dispersed in the amorphous soft segments. These results indicate that a supermolecular structure design of SPU allows for control of the CPh release from the polymer matrix. Medical‐biological tests of the prepared polyurethane device have shown reduced toxic action of the cytostatic drug compared with injections. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 35–43, 2000     

PSD-95: An Effective Target for Stroke Therapy Using Neuroprotective Peptides

Therapies for stroke have remained elusive in the past despite the great relevance of this pathology. However, recent results have provided strong evidence that postsynaptic density protein-95 (PSD-95) can be exploited as an efficient target for stroke neuroprotection by strategies able to counteract excitotoxicity, a major mechanism of neuronal death after ischemic stroke. This scaffold protein is key to the maintenance of a complex framework of protein interactions established at the postsynaptic density (PSD) of excitatory neurons, relevant to neuronal function and survival. Using cell penetrating peptides (CPPs) as therapeutic tools, two different approaches have been devised and advanced to different levels of clinical development. First, nerinetide (Phase 3) and AVLX-144 (Phase 1) were designed to interfere with the coupling of the ternary complex formed by PSD-95 with GluN2B subunits of the N-methyl-D-aspartate type of glutamate receptors (NMDARs) and neuronal nitric oxide synthase (nNOS). These peptides reduced neurotoxicity derived from NMDAR overactivation, decreased infarct volume and improved neurobehavioral results in different models of ischemic stroke. However, an important caveat to this approach was PSD-95 processing by calpain, a pathological mechanism specifically induced by excitotoxicity that results in a profound alteration of survival signaling. Thus, a third peptide (TP95₄₁₄) has been recently developed to interfere with PSD-95 cleavage and reduce neuronal death, which also improves neurological outcome in a preclinical mouse model of permanent ischemia. Here, we review recent advancements in the development and characterization of PSD-95-targeted CPPs and propose the combination of these two approaches to improve treatment of stroke and other excitotoxicity-associated disorders.