Antibody isotype epitope mapping of SARS-CoV-2 Spike RBD protein: Targets for COVID-19 symptomatology and disease control.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) still poses a challenge for biomedicine and public health. To advance the development of effective diagnostic, prognostic, and preventive interventions, our study focused on high-throughput antibody binding epitope mapping of the SARS-CoV-2 spike RBD protein by IgA, IgM and IgG antibodies in saliva and sera of different cohorts from healthy uninfected individuals to SARS-CoV-2-infected unvaccinated and vaccinated asymptomatic, recovered, nonsevere, and severe patients. Identified candidate diagnostic (455-LFRKSNLKPFERD-467), prognostic (395-VYADSFVIRGDEV-407-C-KLH, 332-ITNLCPFGEV-342-C-KLH, 352-AWNRKRI-358-C-KLH, 524-VCGPKKSTNLVKN-536-KLH), and protective (MKLLE-487-NCYFPLQSYGFQPTNGVG-504-GGGGS-446-GGNYNYLYRLFRKSNLKPFERD-467) epitopes were validated with sera from prevaccine and postvaccine cohorts. The results identified neutralizing epitopes and support that antibody recognition of linear B-cell epitopes in RBD protein is associated with antibody isotype and disease symptomatology. The findings in asymptomatic individuals suggest a role for anti-RBD antibodies in the protective response against SARS-CoV-2. The possibility of translating results into diagnostic interventions for the early diagnosis of asymptomatic individuals and prognosis of disease severity provides new tools for COVID-19 surveillance and evaluation of risks in hospitalized patients. These results, together with other approaches, may contribute to the development of new vaccines for the control of COVID-19 and other coronavirus-related diseases using a quantum vaccinomics approach through the combination of protective epitopes.

Secretome of bone marrow mesenchymal stromal cells cultured in a dynamic system induces neuroprotection and modulates microglial responsiveness in an α-synuclein overexpression rat model.

BACKGROUND AIMS: Parkinson's disease (PD) is the second most common neurodegenerative disorder. The etiology of the disease remains largely unknown, but evidence have suggested that the overexpression and aggregation of alpha-synuclein (α-syn) play key roles in the pathogenesis and progression of PD. Mesenchymal stromal cells (MSCs) have been earning attention in this field, mainly due to their paracrine capacity. The bioactive molecules secreted by MSCs, i.e. their secretome, have been associated with enhanced neuronal survival as well as a strong modulatory capacity of the microenvironments where the disease develops. The selection of the appropriate animal model is crucial in studies of efficacy assessment. Given the involvement of α-syn in the pathogenesis of PD, the evidence generated from the use of animal models that develop a pathologic phenotype due to the action of this protein is extremely valuable. Therefore, in this work, we established an animal model based on the viral vector-mediated overexpression of A53T α-syn and studied the impact of the secretome of bone marrow mesenchymal stromal cells MSC(M) as a therapeutic strategy. METHODS: Adult male rats were subjected to α-syn over expression in the nigrostriatal pathway to model dopaminergic neurodegeneration. The impact of locally administered secretome treatment from MSC(M) was studied. Motor impairments were assessed throughout the study coupled with whole-region (striatum and substantia nigra) confocal microscopy evaluation of histopathological changes associated with dopaminergic neurodegeneration and glial cell reactivity. RESULTS: Ten weeks after lesion induction, the animals received secretome injections in the substantia nigra pars compacta (SNpc) and striatum (STR). The secretome used was produced from bone marrow mesenchymal stromal cells MSC(M) expanded in a spinner flask (SP) system. Nine weeks later, animals that received the viral vector containing the gene for A53T α-syn and treated with vehicle (Neurobasal-A medium) presented dopaminergic cell loss in the SNpc and denervation in the STR. The treatment with secretome significantly reduced the levels of α-syn in the SNpc and protected the dopaminergic neurons (DAn) within the SNpc and STR. CONCLUSIONS: Our results are aligned with previous studies in both α-syn Caenorhabditis elegans models, as well as 6-OHDA rodent model, revealing that secretome exerted a neuroprotective effect. Moreover, these effects were associated with a modulation of microglial reactivity supporting an immunomodulatory role for the factors contained within the secretome. This further supports the development of new studies exploring the effects and the mechanism of action of secretome from MSC(M) against α-syn-induced neurotoxicity.

Predicting attachment in Portuguese infants born very or extremely preterm: Understanding the roles of infant regulatory behavior, maternal sensitivity, and risk factors.

A growing body of research shows that early attachment relationships are foundational for children's later developmental and psychosocial outcomes. However, findings are mixed regarding whether preterm birth predicts later attachment, but insecurity is generally more prevalent among infants at higher medical and/or social/familial risk. This longitudinal study aimed to identify specific relational, familial/demographic, and perinatal predictors of attachment in a sample of 63 Portuguese infants born very or extremely preterm (VEPT, <32 gestational weeks) and their mothers from diverse socioeconomic backgrounds. One-third of the mothers had social/family risk factors (e.g., single parent, immigrant, unemployed, low education, and/or low income). At 3 months (corrected age), dyads were observed during social interaction in the Face-to-Face Still-Face paradigm (FFSF) and during free play. At 12 months, mother-infant dyads were observed in Ainsworth's Strange Situation. Over half (58.7%) of the infants were classified as insecurely attached. Social-Positive Oriented regulatory behavior pattern, higher maternal sensitivity, higher infant cooperation during free play, number of siblings and an absence of social/family risk factors were associated with attachment security. Perinatal variables were unrelated to attachment. Findings indicate that both relational and social contextual factors contribute to attachment in this biologically vulnerable sample.

Un creciente cuerpo investigativo muestra que las relaciones afectivas tempranas son fundamentales para posteriores resultados de desarrollo y sicosociales de los niños. Sin embargo, los resultados son variados acerca de si el nacimiento prematuro predice la afectividad posterior, pero la inseguridad es generalmente más prevalente entre infantes bajo más alto riesgo médico y/o social/familiar. Este estudio longitudinal se propuso identificar factores específicos de predicción de la afectividad, relacionales, familiar/demográficos y perinatales en un grupo muestra de 63 infantes portugueses nacidos muy o extremadamente prematuros (VEPT, < 32 semanas gestacionales) y sus madres de diversos niveles socioeconómicos. Un tercio de las madres tenían factores de riesgo social/familiar (v.g. madre soltera, inmigrante, desempleada, de baja educación y/o de bajos recursos económicos). A los tres meses (edad corregida), se les observó a las díadas durante la interacción social en el paradigma de Cara a Cara y Rostro Inmutable (FFSF) y durante el juego libre. A los 12 meses, se les observó a las díadas madre-infante por medio de la Situación Extraña de Ainsworth. Se clasificó más de la mitad (58.7%) de los infantes como afectivamente inseguros. Entre los factores de predicción de la afectividad segura se incluyó un patrón de conducta regulatoria con orientación social positiva durante FFSF, una sensibilidad materna más alta y la cooperación del infante durante el juego libre, así como la ausencia de factores de riesgo sociales/familiares. Las variables perinatales no estuvieron relacionadas con la afectividad. Los resultados indican que los factores contextuales, tanto relacionales como sociales contribuyen a la afectividad en este grupo biológicamente vulnerable.

Cross-modal coherence and incoherence of early infant interactive behavior: links to attachment in infants born very preterm or full-term.

Infants exhibit flexibly organized configurations of facial, vocal, affective, and motor behavior during caregiver-infant interactions that convey convergent messages about their internal states and desires. Prior work documents that greater cross-modal discrepancy at 4 months predicts disorganized attachment. Here, we evaluated whether: very preterm (VPT) or full-term (FT) status predicts cross-modal coherence or incoherence in infants' behavior with the caregiver at 3 months; and, regardless of prematurity, whether cross-modal interactive coherence or incoherence predicts 12-month attachment. Participants included 155 infants (85 FT; 70 VPT), and their mothers followed from birth to 12 months (corrected age). Infants' cross-modal coherent and incoherent responses were scored microanalytically from videotaped en-face interactions. Infants' attachment security was evaluated during Ainsworth's Strange Situation. Infants born VPT exhibited more incoherent cross-modal responses and insecure attachment than infants born FT. Regardless of prematurity, infants' coherent and incoherent cross-modal interactive behaviors at 3 months predicted different attachment patterns at 12 months.

Differential Gene Expression of Malaria Parasite in Response to Red Blood Cell-Specific Glycolytic Intermediate 2,3-Diphosphoglycerate (2,3-DPG).

Innovative strategies to control malaria are urgently needed. Exploring the interplay between Plasmodium sp. parasites and host red blood cells (RBCs) offers opportunities for novel antimalarial interventions. Pyruvate kinase deficiency (PKD), characterized by heightened 2,3-diphosphoglycerate (2,3-DPG) concentration, has been associated with protection against malaria. Elevated levels of 2,3-DPG, a specific mammalian metabolite, may hinder glycolysis, prompting us to hypothesize its potential contribution to PKD-mediated protection. We investigated the impact of the extracellular supplementation of 2,3-DPG on the Plasmodium falciparum intraerythrocytic developmental cycle in vitro. The results showed an inhibition of parasite growth, resulting from significantly fewer progeny from 2,3-DPG-treated parasites. We analyzed differential gene expression and the transcriptomic profile of P. falciparum trophozoites, from in vitro cultures subjected or not subjected to the action of 2,3-DPG, using Nanopore Sequencing Technology. The presence of 2,3-DPG in the culture medium was associated with the significant differential expression of 71 genes, mostly associated with the GO terms nucleic acid binding, transcription or monoatomic anion channel. Further, several genes related to cell cycle control were downregulated in treated parasites. These findings suggest that the presence of this RBC-specific glycolytic metabolite impacts the expression of genes transcribed during the parasite trophozoite stage and the number of merozoites released from individual schizonts, which supports the potential role of 2,3-DPG in the mechanism of protection against malaria by PKD.

Unilateral Intrastriatal 6-Hydroxydopamine Lesion in Mice: A Closer Look into Non-Motor Phenotype and Glial Response.

Parkinson's disease (PD) is a prevalent movement disorder characterized by the progressive loss of dopaminergic neurons in substantia nigra pars compacta (SNpc). The 6-hydroxydopamine (6-OHDA) lesion is still one of the most widely used techniques for modeling Parkinson's disease (PD) in rodents. Despite commonly used in rats, it can be challenging to reproduce a similar lesion in mice. Moreover, there is a lack of characterization of the extent of behavioral deficits and of the neuronal loss/neurotransmitter system in unilateral lesion mouse models. In this study, we present an extensive behavioral and histological characterization of a unilateral intrastriatal 6-OHDA mouse model. Our results indicate significant alterations in balance and fine motor coordination, voluntary locomotion, and in the asymmetry's degree of forelimb use in 6-OHDA lesioned animals, accompanied by a decrease in self-care and motivational behavior, common features of depressive-like symptomatology. These results were accompanied by a decrease in tyrosine hydroxylase (TH)-labelling and dopamine levels within the nigrostriatal pathway. Additionally, we also identify a marked astrocytic reaction, as well as proliferative and reactive microglia in lesioned areas. These results confirm the use of unilateral intrastriatal 6-OHDA mice for the generation of a mild model of nigrostriatal degeneration and further evidences the recapitulation of key aspects of PD, thereby being suitable for future studies beholding new therapeutical interventions for this disease.

Maternal pre and perinatal experiences with their full-term, preterm and very preterm newborns.

BACKGROUND: Mothers' reports about pregnancy, maternity and their experiences during the perinatal period have been associated with infants' later quality of attachment and development. Yet, there has been little research with mothers of very preterm newborns. This study aimed to explore mothers' experiences related to pregnancy, premature birth, relationship with the newborn, and future perspectives, and to compare them in the context of distinct infants' at-birth-risk conditions. METHODS: A semi-structured interview was conducted with women after birth, within the first 72 h of the newborn's life. A total of 150 women participated and were divided in three groups: (1) 50 mothers of full-term newborns (Gestational Age (GA) ≥ 37 weeks; FT), (2) 50 mothers of preterm newborns (GA 32-36 weeks; PT) and (3) 50 mothers of very preterm newborns (GA < 32 weeks; VPT). RESULTS: Mothers of full-term infants responded more often that their children were calm and that they did not expect difficulties in taking care of and providing for the baby. Mothers of preterm newborns although having planned and accepted well the pregnancy (with no mixed or ambivalent feelings about it) and while being optimistic about their competence to take care of the baby, mentioned feeling frightened because of the unexpected occurrence of a premature birth and its associated risks. Mothers of very preterm newborns reported more negative and distressful feelings while showing more difficulties in anticipating the experience of caring for their babies. CONCLUSION: The results indicate that Health Care Systems and Neonatal Care Policy should provide differentiated psychological support and responses to mothers, babies and families, taking into account the newborns' GA and neonatal risk factors.

Impact of Aging on the 6-OHDA-Induced Rat Model of Parkinson's Disease.

Parkinson's disease (PD) is the second most common age-related neurodegenerative disorder. The neurodegeneration leading to incapacitating motor abnormalities mainly occurs in the nigrostriatal pathway due to the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Several animal models have been developed not only to better understand the mechanisms underlying neurodegeneration but also to test the potential of emerging disease-modifying therapies. However, despite aging being the main risk factor for developing idiopathic PD, most of the studies do not use aged animals. Therefore, this study aimed at assessing the effect of aging in the unilateral 6-hydroxydopamine (6-OHDA)-induced animal model of PD. For this, female young adult and aged rats received a unilateral injection of 6-OHDA into the medial forebrain bundle. Subsequently, the impact of aging on 6-OHDA-induced effects on animal welfare, motor performance, and nigrostriatal integrity were assessed. The results showed that aging had a negative impact on animal welfare after surgery. Furthermore, 6-OHDA-induced impairments on skilled motor function were significantly higher in aged rats when compared with their younger counterparts. Nigrostriatal histological analysis further revealed an increased 6-OHDA-induced dopaminergic cell loss in the SNpc of aged animals when compared to young animals. Overall, our results demonstrate a higher susceptibility of aged animals to 6-OHDA toxic insult.

Visible light activated magnetic photocatalysts for water treatment.

Environmental concerns have been raised regarding the intense contamination of water resources. Currently, numerous contaminants that reach water bodies are not efficiently removed by conventional water treatment methods. Therefore, there arises the need for development and optimization of efficient treatment methods for the removal of such recalcitrant contaminants. Given the circumstances, the present study aims to use of advanced oxidative processes for dye degradation. For this purpose, copper and zinc doped cobalt ferrites were synthesized by coprecipitation, targeting the degradation of methylene blue dye. The photocatalysts were characterized by XRD, WD-XRF, FE-SEM, N2 physisorption isotherms, UV-Vis diffuse reflectance spectroscopy, molecular fluorescence spectroscopy and zeta potential. According to the investigation of the degradation mechanism, the holes and hydroxyl radicals were mainly responsible for the dye's degradation. The obtained photocatalysts displayed promising results with up to 99% of dye degradation, employing conventional visible LED lamps, making the practical use of the catalyst highly viable, as well as the economic matters. Additionally, the synthesized materials' magnetic properties allowed total and efficient separation of the catalyst for its reutilization up to 4 cycles, with no decrease in photocatalytic activity and with low leaching of iron ions to solution.

PCR detection of Ehrlichia ruminantium and Babesia bigemina in cattle from Kwara State, Nigeria: unexpected absence of infection.

Ticks and tick-borne diseases (TBDs) continue to pose an insidious and ever-present threat to livestock and livelihoods across the globe. Two of the most significant TBDs of cattle in Africa are heartwater and babesioisis, caused by Ehrlichia ruminantium and Babesia bigemina respectively. Both pathogens are endemic in Nigeria. However, to date, little data has been published regarding the number of cattle infected. In this study, blood samples were collected from cattle of the Kwara State, north-central Nigeria. Probe-based quantitative PCR (qPCR) and semi-nested PCR were used to investigate the presence of both pathogens, respectively. Our study found all samples (n = 157) to be surprisingly negative for both B. bigemina and E. ruminantium. These results contribute new information on the current burden of these two pathogens in Kwara State and may be helpful in informing more effective targeting of control strategies in Nigeria.

PCR screening of tick-borne agents in sensitive conservation areas, Southeast Portugal.

The Southeast region of Portugal, particularly the Guadiana valley, is currently the reintroduction territory of Lynx pardinus (Iberian lynx), one of the most endangered felids in the world that is only found in the Iberian Peninsula. Over the last century, populations have declined, placing L. pardinus at extremely high risk of extinction in the wild and relying on reintroduction projects. Among the aspects taken into account in the establishment of new populations is the sanitary status of the selected habitats, especially concerning infectious diseases, including tick-borne pathogens (TBPs). This study presents the results of TBPs survey on ticks collected at sensitive conservation areas of Southeast Portugal. From 2012 to 2014, 231 ticks obtained from vegetation, sympatric domestic and wild animals were submitted for analysis. The presence of Babesia spp., Cytauxzoon spp., Theileria spp., Hepatozoon spp., Anaplasma spp., Ehrlichia spp., Candidatus Neoehrlichia mikurensis, among other Anaplasmataceae, and Coxiella burnetii were investigated by PCR. Six tick species were recorded, Dermacentor marginatus (n = 13/5.6%), Hyalomma lusitanicum (n = 175/75.8%), Ixodes ricinus (n = 4/1.7%), Rhipicephalus bursa (n = 7/3.0%), R. pusillus (n = 21/9.1%) and R. sanguineus sensu lato (n = 11/4.8%). The molecular screening confirmed the presence of two tick-borne pathogens, C. burnetii (N = 34) and Anaplasma platys (N = 1), and one tick-endosymbiont, Candidatus Midichloria mitochondrii (N = 45). The results obtained provide new information on the circulation of ticks and TBPs with potential veterinary importance in Iberian lynx habitat.

Molecular detection of pathogens in ticks infesting cattle in Nampula province, Mozambique.

Ticks are ectoparasites that can act as vectors of a large number of pathogens in wild and domestic animals, pets, and occasionally humans. The global threat of emerging or re-emerging tick-borne diseases supports the need for research focused in the zoonotic transmission, especially in countries like Mozambique where rural populations are in close contact with domestic animals. The present study aims to: (1) identify tick species infesting cattle from Monapo and Nacala Porto, districts of Nampula province, Mozambique; and (2) investigate the presence of pathogens in the collected ticks. A total of 646 ticks were collected from cattle and morphologically identified as Amblyomma variegatum, Rhipicephalus microplus, and R. evertsi evertsi. For convenience, 72 A. variegatum and 15 R. microplus from Monapo, and 30 A. variegatum from Nacala Porto were screened for the presence of the selected pathogens: Rickettsia spp. (A. variegatum), and Babesia/Theileria spp. and Anaplasma/Ehrlichia spp. (R. microplus). Rickettsia africae was detected in four of the 72 A. variegatum collected in Monapo (5.6%). Additionally, one R. microplus tick (6.7%) was positive for Theileria velifera, one positive for Colpodella spp., one positive for Candidatus Midichloria mitochondrii, and another one positive for Anaplasma ovis. Using the present approach, no microorganisms were detected in tick samples from Nacala Porto. These findings expand our knowledge about the repertoire of tick-borne microorganisms in ticks in Nampula province, Mozambique.

A new species of Domene Fauvel, 1873 (Coleoptera: Staphylinidae: Paederinae) from a granitic cavity in Serra da Estrela (Portugal).

A new species of the genus Domene Fauvel, 1873-D. viriatoi n. sp.-is described from a granitic natural cavity in Serra da Estrela, Portugal. This subterranean species is diagnosed and compared with closely related species from the Iberian endemic subgenus Lathromene Koch, 1938. The external morphology and male genitalia are illustrated and information on the species` ecology is presented. A dichotomic key to the Lathromene species based on the male genitalia is provided. The need to protect the habitat of this species from human disturbance is commented on.

Mosquito Akirin as a potential antigen for malaria control.

BACKGROUND: The control of vector-borne diseases is important to improve human and animal health worldwide. Malaria is one of the world's deadliest diseases and is caused by protozoan parasites of the genus Plasmodium, which are transmitted by Anopheles spp. mosquitoes. Recent evidences using Subolesin (SUB) and Akirin (AKR) vaccines showed a reduction in the survival and/or fertility of blood-sucking ectoparasite vectors and the infection with vector-borne pathogens. These experiments suggested the possibility of using AKR for malaria control. METHODS: The role of AKR on Plasmodium berghei infection and on the fitness and reproduction of the main malaria vector, Anopheles gambiae was characterized by evaluating the effect of akr gene knockdown or vaccination with recombinant mosquito AKR on parasite infection levels, fertility and mortality of female mosquitoes. RESULTS: Gene knockdown by RNA interference in mosquitoes suggested a role for akr in mosquito survival and fertility. Vaccination with recombinant Aedes albopictus AKR reduced parasite infection in mosquitoes fed on immunized mice when compared to controls. CONCLUSIONS: These results showed that recombinant AKR could be used to develop vaccines for malaria control. If effective, AKR-based vaccines could be used to immunize wildlife reservoir hosts and/or humans to reduce the risk of pathogen transmission. However, these vaccines need to be evaluated under field conditions to characterize their effect on vector populations and pathogen infection and transmission.

Ticks and Tick-Borne Pathogens Circulating in Peri-Domestic Areas in Mainland Portugal.

Over the years, tick-borne pathogens (TBPs) have garnered significant interest due to their medical, veterinary and economic importance. Additionally, TBPs have drawn attention to how these microorganisms interact with their own vectors, increasing the risk to human and animal infection of emerging and reemerging zoonoses. In this sense, ticks, which are obligate hematophagous ectoparasites, have a key role in maintaining and transmitting TBPs among humans and animals. The aim of this study was to assess the prevalence of neglected TBPs in mainland Portugal, namely Anaplasma spp., Babesia spp., Ehrlichia spp. and Neoehrlichia mikurensis. DNA fragments were detected in questing ticks collected from five different ecological areas under investigation. To the best of the authors' knowledge, this study reports new worldwide findings, including B. bigemina infecting Ixodes frontalis, Ixodes ricinus and Rhipicephalus sanguineus sensu lato. Additionally, it presents new findings in Portugal of N. mikurensis infecting I. ricinus and of presumably Wolbachia endosymbionts being detected in I. ricinus. Overall, there were 208 tick samples that were negative for all screened TBPs. The results herein obtained raise concerns about the circulation of neglected TBPs in mainland Portugal, especially in anthropophilic ticks, highlighting the importance of adopting a One Health perspective.

A small proportion of Zebu genetic background in crossbred calves may not be enough to improve resistance against natural bovine Babesia spp. infections.

The main objective of cattle breeders in tropical and subtropical regions is to acquire animals with taurine-productive traits adapted to the broad weather range of these regions. However, one of the main challenges on using taurine genetics in these areas is the high susceptibility of these animals to tick-borne diseases. Consequently, the present study evaluated from 10 November 2021-19 April 2022, the over 13 assessments, the Babesia bovis and Babesia bigemina DNA loads and the IgG anti-B. bovis and anti-B. bigemina levels in Angus (n = 17, 100% Taurine) and Ultrablack (n = 14, ∼82% taurine and 18% Zebu) calves. Data were analyzed using a multivariate mixed model with repeated measures of the same animal including the fixed effects of evaluation, genetic group, sex, Babesia spp., and their interactions. The repeatability values were estimated from the (co)variances matrix and expressed for each species. The correlations between the DNA loads (CNlog) and IgG titers (S/P) values for the two species were also estimated using the same model. Regarding the specific IgG antibody titers for both Babesia spp., no significant differences were observed between the two genetic groups. However, for B. bovis and B. bigemina DNA loads, Ultrablack calves presented significantly higher values than Angus calves. Under the conditions evaluated in this study, our findings suggest that the low percentage of Zebu genetic in the Ultrablack breed was insufficient to improve resistance against babesiosis. Further studies must demonstrate if the low percentages of Zebu genetics in Taurine breeds can modify the susceptibility to babesiosis infections.

In vitro neuronal and glial response to magnetically stimulated piezoelectric poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV)/cobalt ferrite (CFO) microspheres.

Polymer biomaterials are being considered for tissue regeneration due to the possibility of resembling different extracellular matrix characteristics. However, most current scaffolds cannot respond to physical-chemical modifications of the cell microenvironment. Stimuli-responsive materials, such as electroactive smart polymers, are increasingly gaining attention once they can produce electrical potentials without external power supplies. The presence of piezoelectricity in human tissues like cartilage and bone highlights the importance of electrical stimulation in physiological conditions. Although poly(vinylidene fluoride) (PVDF) is one of the piezoelectric polymers with the highest piezoelectric response, it is not biodegradable. Poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) is a promising copolymer of poly(hydroxybutyrate) (PHB) for tissue engineering and regeneration applications. It offers biodegradability, piezoelectric properties, biocompatibility, and bioactivity, making it a superior option to PVDF for biomedical purposes requiring biodegradability. Magnetoelectric polymer composites can be made by combining magnetostrictive particles and piezoelectric polymers to further tune their properties for tissue regeneration. These composites convert magnetic stimuli into electrical stimuli, generating local electrical potentials for various applications. Cobalt ferrites (CFO) and piezoelectric polymers have been combined and processed into different morphologies, maintaining biocompatibility for tissue engineering. The present work studied how PHBV/CFO microspheres affected neural and glial response in spinal cord cultures. It is expected that the electrical signals generated by these microspheres due to their magnetoelectric nature could aid in tissue regeneration and repair. PHBV/CFO microspheres were not cytotoxic and were able to impact neurite outgrowth and promote neuronal differentiation. Furthermore, PHBV/CFO microspheres led to microglia activation and induced the release of several bioactive molecules. Importantly, magnetically stimulated microspheres ameliorated cell viability after an in vitro ROS-induced lesion of spinal cord cultures, which suggests a beneficial effect on tissue regeneration and repair.

Toward the discovery of inhibitors of babesipain-1, a Babesia bigemina cysteine protease: in vitro evaluation, homology modeling and molecular docking studies.

Babesia bigemina is a protozoan parasite that causes babesiosis, a disease with a world-wide distribution in mammals, principally affecting cattle and man. The unveiling of the genome of B. bigemina is a project in active progress that has already revealed a number of new targets with potential interest for the design of anti-babesiosis drugs. In this context, babesipain-1 has been identified as a proteolytically active enzyme whose three-dimensional structure has not been resolved yet, but which is known to be inhibited by cysteine proteases inhibitors such as E64, ALLN, leupeptin, and vinyl sulfones. In this work, we introduce (1) a homology model of babesipain-1; (2) a comparison between babesipain-1 and falcipain-2, a cysteine protease of the malaria parasite Plasmodium falciparum; (3) in vitro data for babesipain-1 inhibition by HEDICINs and HECINs, previously reported as modest inhibitors of falcipain-2; and (4) the docked binding conformations of HEDICINs and HECINs in the model of babesipain-1. HEDICINs presented similar preferred binding conformations for both babesipain-1 and falcipain-2. However, in vitro bioassay shows that HEDICINs and HECINs are better inhibitors of babesipain-1 than of falcipain-2, which could be explained by observed differences between the active pockets of these proteins in silico. Results presented herein provide a valuable contribution to future computer-aided molecular design of new babesipain-1 inhibitors.

Generation of an antibody that recognizes Plasmodium chabaudi cysteine protease (chabaupain-1) in both sexual and asexual parasite life cycle and evaluation of chabaupain-1 vaccine potential.

Malaria cysteine proteases have been shown to be immunogenic and are being exploited as serodiagnostic markers, drug and vaccine targets. Several Plasmodium spp. cysteine proteases have been described and the best characterized of these are the falcipains, a family of papain-family enzymes. Falcipain-2 and falcipain-3 act in concert with other proteases to hydrolyze host erythrocyte hemoglobin in the parasite food vacuole. Falcipain-1 has less similarity to the other falcipains and its physiological role in parasite asexual blood stage still remains uncertain. Immunolocalization studies using an antibody developed against the Plasmodium chabaudi recombinant chabaupain-1, the falcipain-1 ortholog, were performed confirming its cellular localization in both erythrocyte and mosquito ookinete stage. Immunostaining of chabaupain-1 preferentially in apical portion of parasite ookinete suggests that this protease may be related with parasite egression from mosquito midgut. Immune responses to chabaupain-1 were evaluated using two different adjuvants, chitosan nanoparticles and hydroxide aluminum. Mice immunized with the recombinant protein alone or in association with nanoparticles were challenged with P. chabaudi showing that immunization with the recombinant protein confers partial protection to blood stage infection in BALB/c animal model.

Hidden haemosporidian infections in Ruffs (Philomachus pugnax) staging in Northwest Europe en route from Africa to Arctic Europe.

In their African freshwater wintering habitats, shorebirds show a high prevalence of blood parasites, whereas no parasites are detected elsewhere along the migration route. We looked at two genera of haemosporidian parasites, Haemoproteus and Plasmodium, in the long-distance migrating Ruff (Philomachus pugnax) along a geographical/seasonal gradient to verify the infection pattern and examine possible hidden organ infections at European staging areas. We amplified parasite DNA from blood of 53 healthy birds wintering in Mali, 53 samples of seven organ tissues (spleen, liver, kidneys, heart, lungs, brain, and pectoral muscle) from healthy individuals caught during spring migration, and 18 weak birds found sick in summer in The Netherlands. We confirm that Ruffs wintering in Africa carried blood infections and that some infections developed into hidden organ infections during spring migration. Moreover, sick birds either had new infections (in one juvenile) or relapses (in an adult harboring an African lineage). Our results suggest that some parasites develop latency. This strategy may be beneficial for the parasite as it may take control over reappearance in the blood to help further transmission.