Characterization of polyphenols and carbohydrates exuded by Phaeodactylum tricornutum diatom grown under Cu stress

This study is focused on analysing polyphenols and carbohydrates released by Phaeodactylum tricornutum (P. tricornutum) diatoms cultured in natural seawater enriched with sublethal and lethal Cu doses. Cu concentrations of 0.31, 0.79 and 1.57 µM reduced cell densities by 37, 82 and 91%, respectively, compared to the control. The total sum of all identified polyphenols and total carbohydrates released by cells grown under lethal Cu levels increased up to 18.8 and 107.4 times, respectively, compared to data from a control experiment. Four different in vitro assays were used to estimate the antioxidant activities of the extracellular compounds: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition, cupric ion reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power and Cu complexing ability (CCA). The highest antioxidant activities were observed in the Cu lethal treatments, where the CCA assay exhibited a greater increase (up to 32.2 times higher than that found in the control experiment) to reduce the concentration of free Cu in the medium and its toxicity. The presence of Cu stimulated the release of polyphenols and carbohydrates to the medium as a detoxification mechanism to survive under lethal levels of Cu regulating its speciation.

Usefulness of NT-proBNP in dogs with heartworm: could this biomarker be useful to evaluate pulmonary hypertension?

BACKGROUND

In recent years, the usefulness of echocardiography and serum biomarkers in the diagnosis of pulmonary hypertension (PH) in dogs with heartworm disease has been studied. Previously, N-terminal pro B-type natriuretic peptide (NT-proBNP) has shown high concentrations in dogs with heart disease and/or PH as well as its usefulness as a prognostic indicator, but it has never been evaluated in the diagnosis and prognosis of PH in dogs with heartworm disease. The aim was to evaluate the serum concentrations of NT-proBNP in dogs infected by Dirofilaria immitis to determine its usefulness as a tool to detect precapillary PH.

METHODS

NT-proBNP was determined in 50 heartworm-infected dogs. Presence/absence of PH was determined echocardiographically, using the Right Pulmonary Artery Distensibility Index (RPAD Index) and the systolic flow of tricuspid regurgitation mainly, together with other echocardiographic measurements following the guidelines of the American College of Veterinary Internal Medicine (ACVIM) for the diagnosis of PH. Other epidemiological parameters (breed, age, sex, status: client-owned or shelter dogs) and clinical parameters (microfilaremia, parasite burden, presence of symptoms, body condition) were collected as well.

RESULTS

Moderate-severe PH was present in 40% of the dogs (RPAD Index < 29.5%), NT-proBNP concentrations being significantly higher compared with dogs that did not have PH. A cutoff for NT-proBNP of ≥ 1178.45 pmol/l showed a sensitivity of 64.3% and a specificity of 95.5% for the presence of moderate-severe PH. Older dogs and dogs from shelters showed significantly higher NT-proBNP concentrations. Dogs with symptoms and low body condition presented significantly higher NT-proBNP concentrations as well.

CONCLUSIONS

The determination of NT-pro-BNP concentration can be a useful tool in the diagnostic work-up of dogs with heartworm disease and associated PH and can help to identify animals in the more advanced stage of this disorder.

Is Zooplankton an Entry Point of Microplastics into the Marine Food Web?

Microplastics (MPs) overlap in size with phytoplankton and can be ingested by zooplankton, transferring them to higher trophic levels. Copepods are the most abundant metazoans among zooplankton and the main link between primary producers and higher trophic levels. Ingestion of MPs has been investigated in the laboratory, but we still know little about the ingestion of MPs by zooplankton in the natural environment. In this study, we determined the concentration and characteristics of MPs down to 10 μm in zooplankton samples, sorted calanoid copepods, and fecal pellets collected in the Kattegat/Skagerrak Sea (Denmark). We found a median concentration of 1.7 × 10-3 MPs ind-1 in the zooplankton samples, 2.9 × 10-3 MPs ind-1 in the sorted-copepods, and 3 × 10-3 MPs per fecal pellet. Most MPs in the zooplankton samples and fecal pellets were fragments smaller than 100 μm, whereas fibers dominated in the sorted copepods. Based on the collected data, we estimated a MP budget for the surface layer (0-18 m), where copepods contained only 3% of the MPs in the water, while 5% of the MPs were packed in fecal pellets. However, the number of MPs exported daily to the pycnocline via fecal pellets was estimated to be 1.4% of the total MPs in the surface layer. Our results indicate that zooplankton are an entry point of small MPs in the food web, but the number of MPs in zooplankton and their fecal pellets was low compared with the number of MPs found in the water column and the occurrence and/or ingestion of MPs reported for nekton. This suggests a low risk of MP transferring to higher trophic levels through zooplankton and a quantitatively low, but ecologically relevant, contribution of fecal pellets to the vertical exportation of MPs in the ocean.

Characterization of PLA Sheets Prepared by Stretching under Different Conditions: Influence of Reprocessing and Establishing Optimal Conditions

Polylactide (PLA) is one of the most commonly used biomaterials nowadays, with many recognized benefits, particularly in the packaging and single-use products industries. However, little research has been conducted on its stretching behavior. This work investigates the optimal conditions of biaxial stretching of injection-molded PLA samples produced under different processing conditions (pressure, drying, and pre-processing by extrusion, to simulate a recycling step). The injection-molded samples were characterized to determine their mechanical, thermal and thermo-mechanical behavior, water absorption, thermal behavior, and crystallization kinetics. The extruded samples showed reduced thermal stability, lower viscosity, decreased mechanical properties, and higher crystallization rates due to thermal degradation. However, the stretched samples provided similar properties regardless of the materials pre-processing. Regarding the assessment of the biaxial stretching process, processing at lower temperatures provides the films with a higher yield and breaking strength, while the time and strain rates have little influence on such properties. It was then determined that 82 °C is the optimal temperature for stretching the PLA samples. An increase in the stretch ratio provided a higher elastic modulus and higher values of opacity due to an increased crystallinity induced by stress during the process. Films as thin as 50 μm can be obtained by biaxially stretching injection-molded preforms, producing a deformation over 150% and acquiring good mechanical properties: about 90 MPa for the yield and a breaking strength and elastic modulus of 4000 MPa.

Feline heartworm disease and environmental allergens hypersensitivity: is there a link?

BACKGROUND

Cats can be infected by Dirofilaria immitis, the causative agent of heartworm disease, characterized by respiratory signs, airway hyperreactivity, remodelling and inflammation. Allergy is a multifactorial pathology, and the role of a number of helminth parasites in the development of allergies in humans and other species has been demonstrated in many studies. The aim of the present study was to verify whether cats seropositive for D. immitis present hypersensitivity to some environmental allergens.

METHODS

Blood samples were collected from 120 cats and tested for the presence of specific immunoglobulin G antibodies against D. immitis and for hypersensitivity to 20 allergens, using commercial allergen test kits.

RESULTS

Of the 120 cats tested, 72 (60.0%) were seropositive for anti-D. immitis IgG and 55 (45.8%) showed clinical signs of heartworm disease of a respiratory nature. The results of testing with the allergen kits showed that 50.8% of cats were seropositive for ≥ 1 allergens, with the most common allergens being Dermatophagoides farinae (25.8%), Dermatophagoides pteronyssinus (20.0%), Malassezia (17.5%) and Ctenocephalides felis (14.2%). The prevalence of allergies was significantly higher-by almost threefold-in cats seropositive for D. immitis (68.1% vs. 25%). There were no significant differences between the prevalence of allergic cats and presence/absence of symptoms, and the results confirmed that symptoms were not a decisive factor for the presence of allergies. The risk for developing allergies was 6.3-fold higher in cats seropositive for D. immitis than in cats that were seronegative, confirming that seropositivity for D. immitis is a risk factor.

CONCLUSIONS

Cats with confirmed heartworm can develop serious respiratory signs, potentially leading to progression to permanent lung injury and predisposing cats to hyperresponsive airway disease. Previous studies have shown that seropositivity for D. immitis and Wolbachia is related to the presence of bronchoconstriction and bronchospasm in the affected cat. The results support the suspicion that contact with D. immitis may be a risk factor for the presence of allergies.

Copper toxicity leads to accumulation of free amino acids and polyphenols in Phaeodactylum tricornutum diatoms

This work is focused on the effect of lethal and sub-lethal copper (Cu) concentrations on the free amino acid and polyphenol production by the marine diatom Phaeodactylum tricornutum (P. tricornutum) after 12, 18, and 21 days of exposure. The concentrations of 10 amino acids (arginine, aspartic acid, glutamic acid, histidine, lysine, methionine, proline, valine, isoleucine, and phenylalanine) and 10 polyphenols (gallic acid, protocatechuic acid, p-coumaric acid, ferulic acid, catechin, vanillic acid, epicatechin syringic acid, rutin, and gentisic acid) were measured by RP-HPLC. Under lethal doses of Cu, free amino acids reached levels significantly higher than those in the control cells (up to 21.9 times higher), where histidine and methionine showed the highest increases (up to 37.4 and 65.8 times higher, respectively). The total phenolic content also increased up to 11.3 and 5.59 times higher compared to the reference cells, showing gallic acid the highest increase (45.8 times greater). The antioxidant activities of cells exposed to Cu were also enhanced with increasing doses of Cu(II). They were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging ability (RSA), cupric ion reducing antioxidant capacity (CUPRAC), and ferric reducing antioxidant power (FRAP) assays. Malonaldehyde (MDA) exhibited the same tendency: cells grown at the highest lethal Cu concentration yielded the highest MDA level. These findings reflect the involvement of amino acids and polyphenols in protective mechanisms to overcome the toxicity of copper in marine microalgae.

Data mining methodology for obtaining epidemiological data in the context of road transport systems

Millions of people use public transport systems daily, hence their interest for the epidemiology of respiratory infectious diseases, both from a scientific and a health control point of view. This article presents a methodology for obtaining epidemiological information on these types of diseases in the context of a public road transport system. This epidemiological information is based on an estimation of interactions with risk of infection between users of the public transport system. The methodology is novel in its aim since, to the best of our knowledge, there is no previous study in the context of epidemiology and public transport systems that addresses this challenge. The information is obtained by mining the data generated from trips made by transport users who use contactless cards as a means of payment. Data mining therefore underpins the methodology. One achievement of the methodology is that it is a comprehensive approach, since, starting from a formalisation of the problem based on epidemiological concepts and the transport activity itself, all the necessary steps to obtain the required epidemiological knowledge are described and implemented. This includes the estimation of data that are generally unknown in the context of public transport systems, but that are required to generate the desired results. The outcome is useful epidemiological data based on a complete and reliable description of all estimated potentially infectious interactions between users of the transport system. The methodology can be implemented using a variety of initial specifications: epidemiological, temporal, geographic, inter alia. Another feature of the methodology is that with the information it provides, epidemiological studies can be carried out involving a large number of people, producing large samples of interactions obtained over long periods of time, thereby making it possible to carry out comparative studies. Moreover, a real use case is described, in which the methodology is applied to a road transport system that annually moves around 20 million passengers, in a period that predates the COVID-19 pandemic. The results have made it possible to identify the group of users most exposed to infection, although they are not the largest group. Finally, it is estimated that the application of a seat allocation strategy that minimises the risk of infection reduces the risk by 50%.

Seroprevalence of Feline Heartworm in Spain: Completing the Epidemiological Puzzle of a Neglected Disease in the Cat

Feline heartworm is a vector-borne zoonotic disease caused by Dirofilaria immitis. It is a cosmopolitan disease that is continuously expanding. Spain is considered an endemic country; however, although there are many published studies in dogs, feline heartworm has been poorly studied in this country. Thus, the objective was to analyze the exposure to D. immitis throughout Spain to complete the epidemiological map in the feline species. For this, 6,588 feline serum samples were analyzed for the presence of D. immitis antigens and antibodies against D. immitis and Wolbachia. The results were analyzed according to sex, age, breed, habitat, origin (owned or shelter cats), presence of clinical signs, use of preventive, location and climatology. The results showed a prevalence of 0.5% and a seroprevalence of 9.4%. The highest antibody seroprevalences were reported in the Canary Islands and the Balearic Islands (19.2 and 16%, respectively), as well as in the autonomous communities located on the Mediterranean coast (9.2–11.2%). Seropositive cats were found in both indoor and outdoor cats, and from 6 months of age. Furthermore, only 5.8% of cats received regular prophylactic treatment. The results show that feline dirofilariasis is widely distributed throughout the national territory and corroborate that, where infected dogs are present, there are cats exposed to the parasite. It is necessary to implement efficient awareness and prophylaxis measures to control the incidence and expansion of feline heartworm in Spain.

Pump-underway ship intake: An unexploited opportunity for Marine Strategy Framework Directive (MSFD) microplastic monitoring needs on coastal and oceanic waters

Broad scale sampling methods for microplastic monitoring in the open ocean waters remain a challenge in oceanography. A large number of samples is required to understand the distribution, abundance and fate of microplastic particles in the environment. Despite more than a decade of widespread study, there is currently no established time series of microplastic measurements and the research community is yet to establish a standardised set of methods that will allow data to be collected in a quick, affordable and interoperable way. We present a sampling technique involving the connection of a custom-built microplastic sampling device to the pump-underway ship intake system of a research vessel (RV) as an unexploited opportunity for oceanic monitoring needs concerning microplastic abundance and distribution. The method is cost effective, highly versatile and accurate, and is able to sample particles down to 50μm from opportunity platforms, thus contributing to an emerging area of study, and in particular helping to increase the monitoring reporting of data, and thereby serving as a valuable aid for the implementation of the Marine Strategy Framework Directive (MSFD). Sampling was performed during three consecutive oceanographic cruises in the subtropical NE Atlantic over a year, sampling subsurface waters (4 m depth) during navigation and while on coastal and oceanic stations. Microplastic particles were found in all stations and transects sampled. Fibres (64.42%) were predominant over fragments (35.58%), with the concentration values falling within the ranges of data reported for other areas of the Atlantic.

Should MASP-2 Deficiency Be Considered a Primary Immunodeficiency? Relevance of the Lectin Pathway

Mannose-binding lectin (MBL)-associated serine protease-2 (MASP-2) is an indispensable enzyme for the activation of the lectin pathway of complement. Its deficiency is classified as a primary immunodeficiency associated to pyogenic bacterial infections, inflammatory lung disease, and autoimmunity. In Europeans, MASP-2 deficiency, due to homozygosity for c.359A > G (p.D120G), occurs in 7 to 14/10,000 individuals. We analyzed the presence of the p.D120G mutation in adults (increasing the sample size of our previous studies) and children. Different groups of patients (1495 adults hospitalized with community-acquired pneumonia, 186 adults with systemic lupus erythematosus, 103 pediatric patients with invasive pneumococcal disease) and control individuals (1119 healthy adult volunteers, 520 adult patients without history of relevant infectious diseases, and a pediatric control group of 311 individuals) were studied. Besides our previously reported MASP-2-deficient healthy adults, we found a new p.D120G homozygous individual from the pediatric control group. We also reviewed p.D120G homozygous individuals reported so far: a total of eleven patients with a highly heterogeneous range of disorders and nine healthy controls (including our four MASP-2-deficient individuals) have been identified by chance in association studies. Individuals with complete deficiencies of several pattern recognition molecules of the lectin pathway (MBL, collectin-10 and collectin-11, and ficolin-3) as well as of MASP-1 and MASP-3 have also been reviewed. Cumulative evidence suggests that MASP-2, and even other components of the LP, are largely redundant in human defenses and that individuals with MASP-2 deficiency do not seem to be particularly prone to infectious or autoimmune diseases.

Use of Hyperspectral/Multispectral Imaging in Gastroenterology. Shedding Some⁻Different⁻Light into the Dark

Hyperspectral/Multispectral imaging (HSI/MSI) technologies are able to sample from tens to hundreds of spectral channels within the electromagnetic spectrum, exceeding the capabilities of human vision. These spectral techniques are based on the principle that every material has a different response (reflection and absorption) to different wavelengths. Thereby, this technology facilitates the discrimination between different materials. HSI has demonstrated good discrimination capabilities for materials in fields, for instance, remote sensing, pollution monitoring, field surveillance, food quality, agriculture, astronomy, geological mapping, and currently, also in medicine. HSI technology allows tissue observation beyond the limitations of the human eye. Moreover, many researchers are using HSI as a new diagnosis tool to analyze optical properties of tissue. Recently, HSI has shown good performance in identifying human diseases in a non-invasive manner. In this paper, we show the potential use of these technologies in the medical domain, with emphasis in the current advances in gastroenterology. The main aim of this review is to provide an overview of contemporary concepts regarding HSI technology together with state-of-art systems and applications in gastroenterology. Finally, we discuss the current limitations and upcoming trends of HSI in gastroenterology.