Retrograde delivery of photosensitizer (TPPp-O-beta-GluOH)3 selectively potentiates its photodynamic activity

Photodynamic therapy involves administration of a photosensitizing drug and its subsequent activation by visible light of the appropriate wavelength. Several approaches to increasing the specificity of photosensitizers for cancerous tissues and, in particular, through their conjugation to ligands that are directed against tumor-associated antigens have been investigated. Here, we have studied the delivery of the photocytotoxic porphyrin compound TPP(p-O-beta-D-GluOH)3 into tumor cells that overexpress the glycosphingolipid Gb3, using the Gb3-binding nontoxic B-subunit of Shiga toxin (STxB) as a vector. To allow for site-directed chemical coupling, an STxB variant carrying a free sulfhydryl moiety at its C-terminal end has been used. Binding affinity, cellular uptake, singlet oxygen quantum yield, and phototoxicity of the conjugate have been examined. Despite some effect of coupling on both the photophysical properties of TPP(p-O-beta-D-GluOH)3 and the affinity of STxB for its receptor, the conjugate exhibited a higher photocytotoxic activity than the photosensitizer alone and was exquisitely selective for Gb3-expressing tumor cells. Furthermore, our data strongly suggest that STxB-mediated retrograde delivery of the photosensitizer to the biosynthetic/secretory pathway is critical for optimal cytotoxic activity. In conclusion, a strong rationale for using retrograde delivery tools such as STxB in combination with photosensitizing agents for the photodynamic therapy of tumors is presented.     

Mitochondria, endoplasmic reticulum and actin filament behavior after PDT with chloroaluminum phthalocyanine liposomal in HeLa cells

Photodynamic therapy (PDT) for cancer is a therapeutic modality in the treatment of tumors in which visible light is used to activate a photosensitizer. Cell membranes have been identified as an important intracellular target for singlet oxygen produced during the photochemical pathway. This study analyzed the cytotoxicity in specific cellular targets of a photosensitizer used in PDT in vitro. The photosensitizing effects of chloroaluminum phthalocyanine liposomal were studied on the mitochondria, cytoskeleton and endoplasmic reticulum of HeLa cells. Cells were irradiated with a diode laser working at 670 nm, energy density of 4.5 J/cm2 and power density of 45 mW/cm2. Fluorescence microscopic analysis of the mitochondria showed changes in membrane potential. After PDT treatment, the cytoskeleton and endoplasmic reticulum presented basic alterations in distribution. The combined effect of AlPHCl liposomal and red light in the HeLa cell line induced photodamage to the mitochondria, endoplasmic reticulum and actin filaments in the cytoskeleton.     

Pro-oxidant effects of extremely low frequency electromagnetic fields in the land snail Helix aspersa

Pro-oxidant effects of extremely low frequency (ELF) 50-Hz magnetic fields were investigated in the land snail Helix aspersa exposed both in short-term laboratory treatments and under field conditions by maintaining the organisms in the proximity of a power line for up to 2 months. Oxidative perturbations were investigated as individual antioxidants (catalase, glutathione reductase, glutathione S-transferases, and total glutathione) and total scavenging capacity toward peroxyl radicals and hydroxyl radicals. Accumulation of lipid peroxidation products, destabilization of lysosomal membranes, and loss of DNA integrity were also evaluated as markers of cell damage. The overall results indicated an oxidative challenge caused by ELF magnetic fields with particularly prompt and sensitive responses for catalase, glutathione reductase, and the overall capability to neutralize peroxyl radicals. Cell injuries occurred to different extents according to duration and intensity of electromagnetic exposure and confirmed complex cause–effect relationships between pro-oxidant factors, efficiency of antioxidant defenses, and the onset of oxidative toxicity. This study highlights the importance of a multimarker approach for detecting a wide panel of biological responses, the necessity of investigating the long-term effects of early oxidative responses, and the role of ELF in enhancing susceptibility to other forms of pathologies or diseases.     

Effect of entomopathogens on Africanized Apis mellifera L. (Hymenoptera: Apidae)

This study aimed to evaluate the effect of commercially used entomopathogens on Africanized Apis mellifera L. (Hymenoptera: Apidae). Four bioassays were performed: 1) pulverized entomopathogens on A. mellifera; 2) entomopathogens sprayed on a smooth surface; 3) entomopathogens sprayed on soy leaves; and 4) entomopathogens mixed with candy paste (sugar syrup). Five treatments were prepared: sterile distilled water (control), distilled water sterilized with Tween^® 80 (0.01%), and the commercial entomopathogens Metarhizium anisopliae E9 (1.0 × 10⁹ conidia mL^?1), Beauveria bassiana PL63 (1.0 × 10⁸ conidia mL^?1) and Bacillus thuringiensis var. kurstaki HD-1 (3.0 × 10⁸ spores mL^?1). Each treatment consisted of five repetitions, with 20 workers per repetition, which were stored in a plastic box and, later, in a biological oxygen demand (B.O.D.) incubator (27 ± 2 °C, RH of 60% ± 10%, 12-h photophase). The mortality of the workers was evaluated from 1 h to 240 h, and the data were analyzed using Bayesian inference. The workers killed by the ingestion of candy paste contaminated with the pathogens (products) were randomly separated and selected for the removal of the midgut. Each midgut was fixed in Bouin's solution and prepared for histology. B. bassiana was verified to reduce the survival of A. mellifera workers in all bioassays. Moreover, M. anisopliae reduced the survival of A. mellifera workers directly sprayed, on a smooth surface and mixed with candy. B. thuringiensis reduced A. mellifera survival on a smooth surface and mixed with candy paste. However, its effects were lower than that observed by B. bassiana. The treatments with the biological products did not induce morphometric alterations in the midgut of A. mellifera.     

Predicting Positive Citizenship from Adolescence to Young Adulthood: The Effects of a Civic Context

Researchers have theorized that programs to promote positive citizenship should begin with an opportunity for adolescents to participate in civic activities, such as community service or political volunteering. In this article we extend the theory by arguing that a more systemic approach is needed, in which a civic context is developed to promote citizenship. We hypothesize that living within a consistent civic context leads to civic engagement in late adolescence and into young adulthood. We use a diverse, longitudinal dataset to test this hypothesis. We find that social interactions with peers, parent modeling of civic behaviors, and cultural factors, such as ethnicity-specific practices, cumulatively result in a higher level of civic activities among youth and that a continued context that includes these factors results in a higher level of civic activities into adulthood. The implications of our findings are discussed with regard to program and policy development.     

Mortality Predictors in Renal Transplant Recipients with Severe Sepsis and Septic Shock

Introduction

The growing number of renal transplant recipients in a sustained immunosuppressive state is a factor that can contribute to increased incidence of sepsis. However, relatively little is known about sepsis in this population. The aim of this single-center study was to evaluate the factors associated with hospital mortality in renal transplant patients admitted to the intensive care unit (ICU) with severe sepsis and septic shock.

Methods

Patient demographics and transplant-related and ICU stay data were retrospectively collected. Multiple logistic regression was conducted to identify the independent risk factors associated with hospital mortality.

Results

A total of 190 patients were enrolled, 64.2% of whom received kidneys from deceased donors. The mean patient age was 51±13 years (males, 115 [60.5%]), and the median APACHE II was 20 (16–23). The majority of patients developed sepsis late after the renal transplantation (2.1 [0.6–2.3] years). The lung was the most common infection site (59.5%). Upon ICU admission, 16.4% of the patients had ≤1 systemic inflammatory response syndrome criteria. Among the patients, 61.5% presented with ≥2 organ failures at admission, and 27.9% experienced septic shock within the first 24 hours of ICU admission. The overall hospital mortality rate was 38.4%. In the multivariate analysis, the independent determinants of hospital mortality were male gender (OR = 5.9; 95% CI, 1.7–19.6; p = 0.004), delta SOFA 24 h (OR = 1.7; 95% CI, 1.2–2.3; p = 0.001), mechanical ventilation (OR = 30; 95% CI, 8.8–102.2; p<0.0001), hematologic dysfunction (OR = 6.8; 95% CI, 2.0–22.6; p = 0.002), admission from the ward (OR = 3.4; 95% CI, 1.2–9.7; p = 0.02) and acute kidney injury stage 3 (OR = 5.7; 95% CI,1.9–16.6; p = 0.002).

Conclusions

Hospital mortality in renal transplant patients with severe sepsis and septic shock was associated with male gender, admission from the wards, worse SOFA scores on the first day and the presence of hematologic dysfunction, mechanical ventilation or advanced graft dysfunction.     

Transplantation of Induced Pluripotent Stem Cell-derived Mesoangioblast-like Myogenic Progenitors in Mouse Models of Muscle Regeneration

Patient-derived iPSCs could be an invaluable source of cells for future autologous cell therapy protocols. iPSC-derived myogenic stem/progenitor cells similar to pericyte-derived mesoangioblasts (iPSC-derived mesoangioblast-like stem/progenitor cells: IDEMs) can be established from iPSCs generated from patients affected by different forms of muscular dystrophy. Patient-specific IDEMs can be genetically corrected with different strategies (e.g. lentiviral vectors, human artificial chromosomes) and enhanced in their myogenic differentiation potential upon overexpression of the myogenesis regulator MyoD. This myogenic potential is then assessed in vitro with specific differentiation assays and analyzed by immunofluorescence. The regenerative potential of IDEMs is further evaluated in vivo, upon intramuscular and intra-arterial transplantation in two representative mouse models displaying acute and chronic muscle regeneration. The contribution of IDEMs to the host skeletal muscle is then confirmed by different functional tests in transplanted mice. In particular, the amelioration of the motor capacity of the animals is studied with treadmill tests. Cell engraftment and differentiation are then assessed by a number of histological and immunofluorescence assays on transplanted muscles. Overall, this paper describes the assays and tools currently utilized to evaluate the differentiation capacity of IDEMs, focusing on the transplantation methods and subsequent outcome measures to analyze the efficacy of cell transplantation.     

Scale of population synchrony confirms macroecological estimates of minimum viable range size

Global ecosystems are facing a deepening biodiversity crisis, necessitating robust approaches to quantifying species extinction risk. The lower limit of the macroecological relationship between species range and body size has long been hypothesized as an estimate of the relationship between the minimum viable range size (MVRS) needed for species persistence and the organismal traits that affect space and resource requirements. Here, we perform the first explicit test of this assumption by confronting the MVRS predicted by the range-body size relationship with an independent estimate based on the scale of synchrony in abundance among spatially separated populations of riverine fish. We provide clear evidence of a positive relationship between the scale of synchrony and species body size, and strong support for the MVRS set by the lower limit of the range-body size macroecological relationship. This MVRS may help prioritize first evaluations for unassessed or data-deficient taxa in global conservation assessments.