Magnetic functionalization of ZnO nanoparticles surfaces via optically generated methyl radicals

The combination of nuclear and electron magnetic resonance techniques, in pulse and continuous wave regimes, is used to unravel the nature and features of the light-induced magnetic state arising at the surface of chemically prepared zinc oxide nanoparticles (NPs) occurring under 120 K when subjected to a sub-bandgap (405 nm) laser excitation. It is shown that the four-line structure observed around g ∼ 2.00 in the as-grown samples (beside the usual core-defect signal at g ∼ 1.96) arises from surface-located methyl radicals (•CH3), originating from the acetate capped ZnO molecules. By functionalizing the as-grown zinc oxide NPs with deuterated sodium acetate, the •CH3 electron paramagnetic resonance (EPR) signal is replaced by trideuteromethyl (•CD3). For •CH3, •CD3, and core-defect signals, an electron spin echo is detected below ∼100 K, allowing for the spin-lattice and spin-spin relaxation-time measurements for each of them. Advanced pulse-EPR techniques reveal the proton or deuteron spin-echo modulation for both radicals and give access to small unresolved superhyperfine couplings between adjacent •CH3. In addition, electron double resonance techniques show that some correlations exist between the different EPR transitions of •CH3. These correlations are discussed as possibly arising from cross-relaxation phenomena between different rotational states of radicals.

Nanostructured fibrin-based hydrogel membranes for use as an augmentation strategy in Achilles tendon surgical repair in rats

Hydrogels are polymeric biomaterials characterised by their promising biological and biomechanical properties, which make them potential alternatives for use in tendon repair. The aim of the present study was to generate in vitro, and determine the therapeutic efficacy in vivo, of novel nanostructured fibrin-based hydrogels to be used as an augmentation strategy for the surgical repair of rat Achilles tendon injuries. Fibrin, fibrin-agarose and fibrin-collagen nanostructured hydrogels (NFH, NFAH and NFCH, respectively) were generated and their biomechanical properties and cell-biomaterial interactions characterised ex vivo. Achilles tendon ruptures were created in 24 adult Wistar rats, which were next treated with direct repair (control group) or direct repair augmented with the generated biomaterials (6 rats/group). After 4 and 8 weeks, the animals were euthanised for macroscopical and histological analyses. Biomechanical characterisation showed optimal properties of the biomaterials for use in tendon repair. Moreover, biological analyses confirmed that tendon-derived fibroblasts were able to adhere to the surface of the generated biomaterials, with high levels of viability and functionality. In vivo studies demonstrated successful tendon repair in all groups. Lastly, histological analyses disclosed better tissue and extracellular matrix organisation and alignment with biomaterial-based augmentation strategies than direct repair, especially when NFAH and NFCH were used. The present study demonstrated that nanostructured fibrin-collagen hydrogels can be used to enhance the healing process in the surgical repair of tendon ruptures.

Quantitative proteomic analysis of marine biofilms formed by filamentous cyanobacterium

Cyanobacterial molecular biology can identify pathways that affect the adhesion and settlement of biofouling organisms and, consequently, obtain novel antifouling strategies for marine applications. Proteomic analyses can provide an essential understanding of how cyanobacteria adapt to different environmental settings. However, only a few qualitative studies have been performed in some cyanobacterial strains. Considering the limited knowledge about protein expression in cyanobacteria in different growing conditions, a quantitative proteomic analysis by LC-MS/MS of biofilm cells from a filamentous strain was performed. Biofilms were also analysed through standard methodologies for following cyanobacterial biofilm development. Biofilms were formed on glass and perspex at two relevant hydrodynamic conditions for marine environments (average shear rates of 4 s^-1 and 40 s^-1). Biofilm development was higher at 4 s^-1 and no significant differences were found between surfaces. Proteomic analysis identified 546 proteins and 41 were differentially expressed. Differences in protein expression were more noticeable between biofilms formed on glass and perspex at 4 s^-1. When comparing biofilms formed on different surfaces, results suggest that biofilm development may be related to the expression of several proteins like a beta-propeller domain-containing protein, chaperone DnaK, SLH domain-containing proteins, an OMF family outer membrane protein, and/or additional uncharacterized proteins. Regarding the hydrodynamic effect, biofilm development can be related to SOD enzyme expression, to proteins related to photosynthetic processes and to a set of uncharacterized proteins with calcium binding domains, disordered proteins, and others involved in electron transfer activity. Studies that combine distinct approaches are essential for finding new targets for antibiofilm agents. The characterisation performed in this work provides new insights into how shear rate and surface affect cyanobacterial biofilm development and how cyanobacteria adapt to these different environmental settings from a macroscopic standpoint to a proteomics context.

Analysis of outcomes of emergency general and gastrointestinal surgery during the COVID-19 pandemic

BACKGROUND

Few surgical studies have provided adjusted comparative postoperative outcome data among contemporary patients with and without COVID-19 infection and patients treated before the pandemic. The aim of this study was to determine the impact of performing emergency surgery in patients with concomitant COVID-19 infection.

METHODS

Patients who underwent emergency general and gastrointestinal surgery from March to June 2020, and from March to June 2019 in 25 Spanish hospitals were included in a retrospective study (COVID-CIR). The main outcome was 30-day mortality. Secondary outcomes included postoperative complications and failure to rescue (mortality among patients who developed complications). Propensity score-matched comparisons were performed between patients who were positive and those who were negative for COVID-19; and between COVID-19-negative cohorts before and during the pandemic.

RESULTS

Some 5307 patients were included in the study (183 COVID-19-positive and 2132 COVID-19-negative during pandemic; 2992 treated before pandemic). During the pandemic, patients with COVID-19 infection had greater 30-day mortality than those without (12.6 versus 4.6 per cent), but this difference was not statistically significant after propensity score matching (odds ratio (OR) 1.58, 95 per cent c.i. 0.88 to 2.74). Those positive for COVID-19 had more complications (41.5 versus 23.9 per cent; OR 1.61, 1.11 to 2.33) and a higher likelihood of failure to rescue (30.3 versus 19.3 per cent; OR 1.10, 0.57 to 2.12). Patients who were negative for COVID-19 during the pandemic had similar rates of 30-day mortality (4.6 versus 3.2 per cent; OR 1.35, 0.98 to 1.86) and complications (23.9 versus 25.2 per cent; OR 0.89, 0.77 to 1.02), but a greater likelihood of failure to rescue (19.3 versus 12.9 per cent; OR 1.56, 95 per cent 1.10 to 2.19) than prepandemic controls.

CONCLUSION

Patients with COVID-19 infection undergoing emergency general and gastrointestinal surgery had worse postoperative outcomes than contemporary patients without COVID-19. COVID-19-negative patients operated on during the COVID-19 pandemic had a likelihood of greater failure-to-rescue than prepandemic controls.

Pediatric bipolar disorder: Preliminary results of a retrospective study using a nationwide administrative database

Introduction

Bipolar disorder (BD) is a severe and chronic illness characterized by episodic changes in mood. The average onset of BD symptoms is estimated between 18 and 22 years. However, many adults retrospectively report symptoms onset in childhood or adolescence. Over the last decades, pediatric bipolar disease (PBD) has been the focus of increased attention mainly due to controversies surrounding its prevalence, diagnosis and treatment in the pediatric population.

Objectives

To analyze pediatric hospitalizations related to BD held in mainland Portuguese public hospitals between 2000 and 2015.

Methods

This retrospective observational study analyzed all pediatric (<18 years old) inpatient episodes from 2000 to 2015 with a primary BD diagnosis, using an anonymized administrative database including all hospitalization from mainland Portuguese public hospitals. ICD-9-CM codes 296.x were used (excluding codes 296.2x; .3x and .9x). Age at admission, admission type and date, sex, charges and length of stay (LoS) were analyzed.

Results

A total of 348 hospitalizations were analyzed from 258 patients. Patients were mainly young girls (60.6%), with a mean age of 15.24±1.87 years. The majority of the admissions were urgent (81.0%), and the median LoS was 14 days (IQR: 7; 24). Mean hospitalization charges were 3503.1€ with a total sum of 1.2M€ for all the episodes.

Conclusions

PBD hospitalizations occur predominantly in female patients during adolescence. The majority of them are urgent admissions. Descriptive studies will help to describe and characterize sociodemographic and clinical trends in PBD in order to better prevent acute hospitalizations with inevitable social and economic implications.

Metals and low dose IR: Molecular effects of combined exposures using HepG2 cells as a biological model

Uranium mining sites produce residues rich in metals and radionuclides, that may contaminate all environmental matrices, exposing human and non-human biota to low doses of ionizing radiation (LDIR) and to the chemical toxicity of several metals. To date, experimental and radio-epidemiological studies do not provide conclusive evidence of LDIR induced cancer. However, co-exposures (LDIR plus other contaminants), may increase the risks. To determine the potential for genotoxic effects in human cells induced by the exposure to LDIR plus metals, HEPG2 cells were exposed to different concentrations of a uranium mine effluent for 96 h. DNA damage was evaluated using the comet assay and changes in the expression of tumor suppressor and oncogenes were determined using qPCR. Results show that effluent concentrations higher than 5%, induce significant DNA damage. Also, a significant under-expression of ATM and TP53 genes and a significant overexpression of GADD45a gene was observed. Results show that the exposure to complex mixtures cannot be disregarded, as effects were detected at very low doses. This study highlights the need for further studies to clarify the risks of exposure to LDIR along with other stressors, to fully review the IR exposure risk limits established for human and non-human biota.

Evaluation of myopic cornea lenticules. A histochemical and clinical correlation

In this work, we have analyzed the main clinical and corneal histological parameters that may be associated to the spherical equivalent (SE), age and gender of individuals with myopic refractive errors. For this purpose, 108 cornea stroma lenticules were obtained from patients subjected to ReLEx-SMILE myopia correction. Histological analyses were carried out and histochemistry and immunohistochemistry were used to quantify key histological components of the cornea stroma, including mature collagen fibers, reticular and elastic fibers, glycoproteins, proteoglycans, type-V collagen and several crystallins. Clinical and histological data were analyzed to determine their association with SE, age and gender. Results showed a significant correlation between the age range of the patients and the expression of crystallins CRY-α-A, CRY-λ1 and type-V collagen and between CRY-λ1 and corneal thickness, spherical diopters (D) and SE, although correlation between CRY-λ1 and SE was non-significant when age was controlled. Comparison of cases with low myopia and high/moderate myopia found statistical differences for D and lenticule thickness and diameter. The binary logistic regression analysis allowed us to construct a model using two clinical parameters (D and lenticule thickness). Parameters showing significant correlation with the age were the corneal radius, keratometry reading (K), OZ, CRY-α-A and type-V collagen, whereas SE, lenticule thickness, OZ, CRY-λ1 and type-V collagen showed statistically significant differences between the youngest and the oldest patients. A binary logistic regression analysis model was generated including 3 variables (D, cornea radius and OZ). No gender differences were found. The specific clinical and histological modifications found to be associated to the SE and age could be useful for a better understanding of the mechanisms involved in the genesis or progression of myopia and could establish the basement for future therapeutic options.

Is the bone tissue of the femoral neck demineralised in patients with hip fracture?

The aim of this study is to establish the falsifiability of the "osteoporotic hypothesis" for hip fracture, according to which the bone density and mineral composition of bone tissue in patients with hip fracture is poorer than when no such fracture is present, and that this circumstance is relevant to the occurrence of a fracture. The study population consisted of forty patients treated with arthroplasty. Twenty patients with femoral neck fracture and another twenty with hip osteoarthritis received the same diagnostic protocol and the same antibiotic, anaesthetic, surgical and antithrombotic prophylaxis. Levels of calcium (Ca), phosphorus (P) and vitamin D in blood, amongst other values, were determined, and five samples of bone tissue from the proximal femoral metaphysis were obtained and characterised by optical microscopy and microanalytical analysis. No statistically significant differences were observed between the two groups with respect to the trabecular number, area or thickness, or inter-trabecular distance. However, there were differences in the length of the trabeculae, which was greater in the patients with hip osteoarthritis (p = 0.002), but not when the groups were compared by gender. When compared by age, a greater inter-trabecular distance was observed in the patients aged over 75 years (p = 0.036) but there were no differences in the remaining parameters. Serum levels of Ca (p = 0.03), P (p < 0.01) and vitamin D (p < 0.01) were lower in the fracture group. In the quantitative microanalytical analysis, no significant differences were observed in bone levels of Ca or P or in the Ca/P index, nor was there any correlation between serum and levels of bone Ca or P (Ca-0.197:p = 0.314;P-0.274:p = 0.158).Multiple linear regression revealed no correlation between the diagnoses, vitamin D and bone levels of Ca or P. Despite the reduced serum levels of Ca and P in the patients with hip fracture, no correlation was observed with bone levels of Ca and P,which were similar in both groups. There were differences in the organic bone structure, in terms of length and inter-trabecular distance. For patients with osteoporosis, treatment should be aimed at increasing the synthesis of bone trabeculae to reinforce their structure. Nevertheless, no such treatment can prevent falls, and therefore no reduction in hip fractures amongst this population can be assured.

Effects of gold nanoparticles in gilthead seabream-A proteomic approach

Despite the widespread use of nanoparticles (NPs), there are still major gaps of knowledge regarding the impact of nanomaterials in the environment and aquatic animals. The present work aimed to study the effects of 7 and 40 nm gold nanoparticles (AuNPs) - citrate and polyvinylpyrrolidone (PVP) coated - on the liver proteome of the estuarine/marine fish gilthead seabream (Sparus aurata). After 96 h, exposure to AuNP elicited alterations on the abundance of 26 proteins, when compared to the control group. AuNPs differentially affected several metabolic pathways in S. aurata liver cells. Among the affected proteins were those related to cytoskeleton and cell structure, gluconeogenesis, amino acids metabolism and several processes related to protein activity (protein synthesis, catabolism, folding and transport). The increased abundance of proteins associated with energy metabolism (ATP synthase subunit beta), stress response (94 kDa glucose-regulated protein) and cytoskeleton structure (actins and tubulins) may represent the first signs of cellular oxidative stress induced by AuNPs. Although higher gold accumulation was found in the liver of S. aurata exposed to 7 nm PVP-AuNPs, the 7 nm cAuNPs were more bioactive, inducing more effects in liver proteome. Gold accumulated more in the spleen than in the other assessed tissues of S. aurata exposed to AuNPs, highlighting its potential role on the elimination of these NPs.

Cosmological Constraints from Multiple Probes in the Dark Energy Survey

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

Characterization of the human ridged and non-ridged skin: a comprehensive histological, histochemical and immunohistochemical analysis

The structure of the human skin is directly dependent on its location and the mechanical forces to which it is subjected. In the present work, we have performed a comprehensive analysis of the human ridged and non-ridged skin to identify the differences and similarities between both skin types. For this purpose, human skin samples were obtained from dorsal hand skin (DHS), palmar hand skin (PHS), dorsal foot skin (DFS) and plantar foot skin (PFS) from the same cadaveric donors. Histological, histochemical and semiquantitative and quantitative immunohistochemical analyses were carried out to evaluate the epidermis, dermis and basement membrane. Results show that the epithelial layer of ridged skin had larger cell number and size than non-ridged skin for most strata. Melanocytes and Langerhans cells were more abundant in non-ridged skin, whereas Merkel cells were preferentially found in ridged skin. The expression pattern of CK5/6 was slightly differed between non-ridged and ridged skin. Involucrin expression was slightly more intense in non-ridged skin than in ridged skin. Collagen was more abundant in foot skin dermis than in hand skin, and in ridged skin as compared to non-ridged skin. Elastic fibers were more abundant in DHS. Biglycan was more abundant in foot skin than in hand skin. No differences were found for blood and lymphatic vessels. The basement membrane laminin was preferentially found in foot skin. These results revealed important differences at the epithelial, dermal and basement membrane levels that could contribute to a better knowledge of the human skin histology.

Wharton's jelly-derived mesenchymal cells as a new source for the generation of microtissues for tissue engineering applications

Microtissues (MT) are currently considered as a promising alternative for the fabrication of natural, 3D biomimetic functional units for the construction of bio-artificial substitutes by tissue engineering (TE). The aim of this study was to evaluate the possibility of generating mesenchymal cell-based MT using human umbilical cord Wharton's jelly stromal cells (WJSC-MT). MT were generated using agarose microchips and evaluated ex vivo during 28 days. Fibroblasts MT (FIB-MT) were used as control. Morphometry, cell viability and metabolism, MT-formation process and ECM synthesis were assessed by phase-contrast microscopy, functional biochemical assays, and histological analyses. Morphometry revealed a time-course compaction process in both MT, but WJSC-MT resulted to be larger than FIB-MT in all days analyzed. Cell viability and functionality evaluation demonstrated that both MT were composed by viable and metabolically active cells, especially the WJSC during 4-21 days ex vivo. Histology showed that WJSC acquired a peripheral pattern and synthesized an extracellular matrix-rich core over the time, what differed from the homogeneous pattern observed in FIB-MT. This study demonstrates the possibility of using WJSC to create MT containing viable and functional cells and abundant extracellular matrix. We hypothesize that WJSC-MT could be a promising alternative in TE protocols. However, future cell differentiation and in vivo studies are still needed to demonstrate the potential usefulness of WJSC-MT in regenerative medicine.

Tissue engineering strategies for the treatment of tendon injuries: a systematic review and meta-analysis of animal models

OBJECTIVES

Recently, the field of tissue engineering has made numerous advances towards achieving artificial tendon substitutes with excellent mechanical and histological properties, and has had some promising experimental results. The purpose of this systematic review is to assess the efficacy of tissue engineering in the treatment of tendon injuries.

METHODS

We searched MEDLINE, Embase, and the Cochrane Library for the time period 1999 to 2016 for trials investigating tissue engineering used to improve tendon healing in animal models. The studies were screened for inclusion based on randomization, controls, and reported measurable outcomes. The RevMan software package was used for the meta-analysis.

RESULTS

A total of 388 references were retrieved and 35 studies were included in this systematic review. The different biomaterials developed were analyzed and we found that they improve the biomechanical and histological characteristics of the repaired tendon. At meta-analysis, despite a high heterogeneity, it revealed a statistically significant effect in favour of the maximum load, the maximum stress, and the Young's modulus between experimental and control groups. In the forest plot, the diamond was on the right side of the vertical line and did not intersect with the line, favouring experimental groups.

CONCLUSIONS

This review of the literature demonstrates the heterogeneity in the tendon tissue engineering literature. Several biomaterials have been developed and have been shown to enhance tendon healing and regeneration with improved outcomes.Cite this article: D. González-Quevedo, I. Martínez-Medina, A. Campos, F. Campos, V. Carriel. Tissue engineering strategies for the treatment of tendon injuries: a systematic review and meta-analysis of animal models. Bone Joint Res 2018;7:318-324. DOI: 10.1302/2046-3758.74.BJR-2017-0326.

Modulation of hepatic glutathione transferases isoenzymes in three bivalve species exposed to purified microcystin-LR and Microcystis extracts

This study compares the role of hepatic cytosolic glutathione transferases (cGST) isoforms of three different bivalve species to a Microcystis aeruginosa extract and purified MC-LR exposure (both at 150 μg MC-LR L^-1) for 24 h. Characterization and alterations of the cytosolic GST activities in Mytilus galloprovincialis, Ruditapes philippinarum and Corbicula fluminea were measured using four class-specific substrates and changes in individual GST isoforms expression were achieved by a subsequent two-dimensional electrophoresis analysis. Evaluation of cGST activity basal levels using the four class-specific substrates denoted quantitative differences between the three bivalves. Purified MC-LR did not induce any significant response from bivalves. On the other hand, cell extracts caused significant alterations according to bivalves and substrates. Among the three bivalves, only R. philippinarum showed a significant induction of cGST activity using generic 1-chloro-2,4-dinitrobenzene (CDNB) substrate. However, no significant alterations were detected in these clams by cell extracts using the other specific substrates. In contrast, C. fluminea revealed significant induction of cGST activity when using 3,4-dichloronitrobenzene (DCNB) and ethacrynic acid (EA). In M. galloprovincialis, cell extracts promoted a significant decrease of cGST activity when using EA substrate. Altered protein expression was quantitatively detected upon exposure to cell extracts for one spot in R. philippinarum and another for C. fluminea, both upregulated (2.0 and 8.5-fold, respectively) and identified as a sigma1-class GST in the case of the first. The results showed that the three bivalves presented specific adaptive biotransformation responses to MCs and other cyanobacteria compounds supported by the modulation of distinct cGST classes.

Membranes derived from human umbilical cord Wharton's jelly stem cells as novel bioengineered tissue-like constructs

Cell-derived matrices were recently described as novel biomaterials generated by human cells allowed to grow and synthetize their own extracellular matrix in culture. In the present work, we generated and evaluated a novel tissue-like substitute (WDM) consisting of a membrane derived from cultured human Wharton's jelly stem cells. WDM were evaluated ex vivo and in vivo by histochemistry and immunohistochemistry for several mesenchymal cell markers and fibrillar and non-fibrillar extracellular matrix components. Results show that WDM were heterogeneous and consisted of dense cell-poor areas surrounded by cell-rich zones with abundant HWJSC. Histological analyses demonstrated that cell-poor areas were very rich in fibrillar and non-fibrillar extracellular matrix components such as collagen and proteoglycans, and cells in the WDM were highly viable and mostly PCNA-positive. HWJSC in the WDM expressed all markers of this cell type, including CD90, CD105, pan cytokeratin and CK8. In vivo analysis showed that the WDM was highly biocompatible and grafting this membrane in the muscle of laboratory rats was not associated to increased inflammation, necrosis, tumorigenesis or other side effects, while cells properly integrated at the damage site and showed high proliferation index. These results suggest that the structure and composition of the extracellular matrix of these novel WDM could reproduce the situation of native human tissues and that WDM implanted in vivo are highly biocompatible and rapidly integrate in the host tissues. For these reasons, we hypothesize that WDM could be used in regenerative medicine protocols.

Effects of microcystin-LR and cylindrospermopsin on plant-soil systems: A review of their relevance for agricultural plant quality and public health

Toxic cyanobacterial blooms are recognized as an emerging environmental threat worldwide. Although microcystin-LR is the most frequently documented cyanotoxin, studies on cylindrospermopsin have been increasing due to the invasive nature of cylindrospermopsin-producing cyanobacteria. The number of studies regarding the effects of cyanotoxins on agricultural plants has increased in recent years, and it has been suggested that the presence of microcystin-LR and cylindrospermopsin in irrigation water may cause toxic effects in edible plants. The uptake of these cyanotoxins by agricultural plants has been shown to induce morphological and physiological changes that lead to a potential loss of productivity. There is also evidence that edible terrestrial plants can bioaccumulate cyanotoxins in their tissues in a concentration dependent-manner. Moreover, the number of consecutive cycles of watering and planting in addition to the potential persistence of microcystin-LR and cylindrospermopsin in the environment are likely to result in groundwater contamination. The use of cyanotoxin-contaminated water for agricultural purposes may therefore represent a threat to both food security and food safety. However, the deleterious effects of cyanotoxins on agricultural plants and public health seem to be dependent on the concentrations studied, which in most cases are non-environmentally relevant. Interestingly, at ecologically relevant concentrations, the productivity and nutritional quality of some agricultural plants seem not to be impaired and may even be enhanced. However, studies assessing if the potential tolerance of agricultural plants to these concentrations can result in cyanotoxin and allergen accumulation in the edible tissues are lacking. This review combines the most current information available regarding this topic with a realistic assessment of the impact of cyanobacterial toxins on agricultural plants, groundwater quality and public health.

Analysis of the use of microcystin-contaminated water in the growth and nutritional quality of the root-vegetable, Daucus carota

Toxic cyanobacterial blooms are often observed in freshwaters and may reflect the increased eutrophication of these environments and alterations in climate. Cyanotoxins, such as microcystins (MCs), are an effective threat to many life forms, ranging from plants to humans. Despite the research conducted to date on cyanotoxins, the risks associated to the use of contaminated water in agriculture require further elucidation. To tackle this aim, a research was conducted with the root-vegetable Daucus carota. The specific aims of this work were the following: (i) to evaluate the effects of MC-LR on the plant growth and photosynthesis; (ii) to evaluate the nutritional quality of carrot roots; and (iii) to measure bioaccumulation. To this purpose, young carrots were grown in soil during 1 month in natural conditions and exposed to Mycrocystis aeruginosa aqueous extracts containing environmentally realistic concentrations of MC-LR (10 and 50 MC-LR μg/L). The results showed that MC-LR may decrease root growth after 28 days of exposure to 50 μg/L and increase photosynthetic efficiency. We also observed changes in mineral and vitamin content in carrots as a result of the exposure to contaminated water. Moreover, MC-LR was detected in carrot roots by ELISA at very low concentration 5.23 ± 0.47 ng MC eq./g FW. The soil retained 52.7 % of the toxin potentially available for plants. This result could be attributed to MC-LR adsorption by soil particles or due to microbial degradation of the toxin. We conclude that the prolonged use of MC-LR-contaminated water may affect crop growth, alter the nutritional value of vegetable products, and potentiate contamination.

A cytosolic carbonic anhydrase molecular switch occurs in the gills of metamorphic sea lamprey

Carbonic anhydrase plays a key role in CO2 transport, acid-base and ion regulation and metabolic processes in vertebrates. While several carbonic anhydrase isoforms have been identified in numerous vertebrate species, basal lineages such as the cyclostomes have remained largely unexamined. Here we investigate the repertoire of cytoplasmic carbonic anhydrases in the sea lamprey (Petromyzon marinus), that has a complex life history marked by a dramatic metamorphosis from a benthic filter-feeding ammocoete larvae into a parasitic juvenile which migrates from freshwater to seawater. We have identified a novel carbonic anhydrase gene (ca19) beyond the single carbonic anhydrase gene (ca18) that was known previously. Phylogenetic analysis and synteny studies suggest that both carbonic anhydrase genes form one or two independent gene lineages and are most likely duplicates retained uniquely in cyclostomes. Quantitative PCR of ca19 and ca18 and protein expression in gill across metamorphosis show that the ca19 levels are highest in ammocoetes and decrease during metamorphosis while ca18 shows the opposite pattern with the highest levels in post-metamorphic juveniles. We propose that a unique molecular switch occurs during lamprey metamorphosis resulting in distinct gill carbonic anhydrases reflecting the contrasting life modes and habitats of these life-history stages.

An immunohistochemical study of cytokeratins distribution of the human adult male and female urethra

Surgical treatment of diseases affecting long urethral areas represents a challenge in urology. Recent developments of tissue-engineered urethral substitutes represent a hope for patients. However finding an ideal tissue source for urethral reconstruction first requires proper understanding of the native human urethra physiology and a deep knowledge of the histological and molecular features of the native human urethra. Here we present a comprehensive characterization of male and female urethra by histological, histochemical and immunohistochemical methods with a panel of 15 antibodies. The results demonstrated that the histology of the male and female urethra depend on the area where the sample is taken along its length. Proximal areas of male and female urethra have differential expression of the epithelial basal and suprabasal layer markers CK14 and CK10 which distinguished the prostatic/membranous and proximal female urethra from the bulbar/penile and distal female areas of the urethra. The distal male (penile) and female may be further divided by the distinct expression pattern of CK19. On the other hand, the expression of CK5/6 and CK19 also make a distinction of the proximal and distal female urethra. These results should facilitate a more informed selection of donor graft tissues for urethral replacement. Besides, novel bioengineered urethral tissue approaches should take into account the characterization of the different areas of the urethra presented in this work.

Ex vivo and in vivo modulatory effects of umbilical cord Wharton's jelly stem cells on human oral mucosa stroma substitutes

Novel oral mucosa substitutes have been developed in the laboratory using human umbilical cord Wharton's jelly stem cells -HWJSC- as an alternative cell source. In the present work, we have generated human oral mucosa substitutes with oral mucosa keratinocytes and HWJSC to determine the influence of these cell sources on stromal differentiation. First, acellular and cellular stroma substitutes and bilayered oral mucosa substitutes with an epithelial layer consisting of oral mucosa keratinocytes -OM samples- or HWJSC -hOM- were generated. Then, tissues were analyzed by light and electron microscopy, histochemistry and immunohistochemistry to quantify all major extracellular matrix components after 1, 2 and 3 weeks of ex vivo development, and OM and hOM were also analyzed after in vivo grafting. The results showed that bioengineered oral mucosa stromas displayed an adequate fibrillar mesh. Synthesis of abundant collagen fibers was detected in OM and hOM after 3 weeks, and in vivo grafting resulted in an increased collagen synthesis. No elastic or reticular fibers were found. Glycoprotein synthesis was found at the epithelial-stromal layer when samples were grafted in vivo. Finally, proteoglycans, decorin, versican and aggrecan were strongly dependent on the in vivo environment and the presence of a well-structured epithelium on top. The use of HWJSC was associated to an increased synthesis of versican. These results confirm the usefulness of fibrin-agarose biomaterials for the generation of an efficient human oral mucosa stroma substitute and the importance of the in vivo environment and the epithelial-mesenchymal interaction for the adequate differentiation of the bioengineered stroma.

Effects of the naturally-occurring contaminant microcystins on the Azolla filiculoides-Anabaena azollae symbiosis

Harmful algal blooms (HABs) contaminate aquatic ecosystems and are responsible for animal poisoning worldwide. We conducted a toxicity test with the aquatic fern and the biofertilizer, Azolla filiculoides. The sporophytes were exposed to three concentrations (0.01, 0.1 and 1μgmL(-1)) of a microcystin (MC) cyanobacterial crude extract and purified MC-LR. The growth of A. filiculoides decreased only at 1μgmL(-1) crude extract concentration while with MC-LR it decreased at all the tested concentrations, indicating that the presence of other compounds in the crude extract altered toxicity and stimulated the fern growth at lower concentrations (0.01 and 0.1μgmL(-1)). Both phycoerythrocyanin and allophycocyanin levels decreased in all the concentrations of crude extract and MC-LR. The phycocyanin had a marked increase at 0.1μgmL(-1) crude extract concentration and a marked decrease at 1μgmL(-1) MC-LR concentration. These changes in the phycobiliprotein content indicate a shift in the antenna pigments of the cyanobionts of A. filiculoides. The changes in two oxidative stress enzymes, glutathione reductase for the crude extract assay and glutathione peroxidase for MC-LR assay, points towards the induction of stress defense responses. The low bioconcentration factor in both crude extract and MC-LR treatments can suggest the low uptake of microcystins, and indicates that the aquatic fern can be used as a biofertilizer and as animal feed but is not suitable for MC phytoremediation.