Regulatory mechanisms of stem cell differentiation: Biotechnological applications for neurogenesis.

The world population's life expectancy is growing, and neurodegenerative disorders common in old age require more efficient therapies. In this context, neural stem cells (NSCs) are imperative for the development and maintenance of the functioning of the nervous system and have broad therapeutic applicability for neurodegenerative diseases. Therefore, knowing all the mechanisms that govern the self-renewal, differentiation, and cell signaling of NSC is necessary. This review will address some of these aspects, including the role of growth and transcription factors, epigenetic modulators, microRNAs, and extracellular matrix components. Furthermore, differentiation and transdifferentiation processes will be addressed as therapeutic strategies showing their significance for stem cell-based therapy.

Strategic use of organoids and organs-on-chip as biomimetic tools.

Organoid development and organ-on-a-chip are technologies based on differentiating stem cells, forming 3D multicellular structures resembling organs and tissues in vivo. Hence, both can be strategically used for disease modeling, drug screening, and host-pathogen studies. In this context, this review highlights the significant advancements in the area, providing technical approaches to organoids and organ-on-a-chip that best imitate in vivo physiology.

Organoids as a novel tool in modelling infectious diseases.

Infectious diseases worldwide affect human health and have important societal impacts. A better understanding of infectious diseases is urgently needed. In vitro and in vivo infection models have brought notable contributions to the current knowledge of these diseases. Organoids are multicellular culture systems resembling tissue architecture and function, recapitulating many characteristics of human disease and elucidating mechanisms of host-infectious agent interactions in the respiratory and gastrointestinal systems, the central nervous system and the skin. Here, we discuss the applicability of the organoid technology for modeling pathogenesis, host response and features, which can be explored for the development of preventive and therapeutic treatments.

Refractive Surgery for Older Children and Adults with Accommodative Esotropia: A Systematic Review.

INTRODUCTION: Accommodative esotropia (AET) is characterized by an esodeviation of the eyes due to uncorrected hyperopia, deficient fusional divergence, or high accommodative convergence. Decreasing hyperopia would reduce accommodative convergence and strabismus. We sought to review the existing evidence regarding the outcomes of refractive surgery in patients with AET. METHODS: A four-database search (Pubmed, ISI Web of Science, Cochrane, and Scopus) was performed from inception to March 2021 using the following MeSH terms: ("Refractive Surgical Procedures" OR "Keratomileusis, Laser In Situ" OR "Photorefractive Keratectomy" OR "Lens Implantation, Intraocular") AND ("Esotropia" OR "Accommodative Esotropia" OR "Refractive Esotropia" OR "Accommodative Strabismus"). No meta-analysis was performed due to studies' heterogeneity. RESULTS: Twenty-eight studies including 22 case series enrolling 378 patients and 6 case reports enrolling 8 patients were selected among 185 original abstracts. In the case series, a total of 378 patients (726 eyes) were recruited with an age range of 8-52 years. All studies reported mean follow-up periods of at least 12 months. Photorefractive keratectomy was performed in 7 studies, laser-assisted in situ keratomileusis in 9 studies, laser-assisted sub-epithelial keratectomy was reported in 1 study, and 3 studies implanted intraocular lenses, including iris-fixated and collamer. Considering the adult patients with a preoperative corrected esodeviation ≤10 prism diopters (PD) (n = 129), all but 5 (3.9%) presented orthophoria or ≤10PD after refractive surgery. All children but 4 (4.5%) ended up with an esodeviation ≤10PD after surgery with those exceptions being in the range of 11-15PD. Six case reports were included in this review, comprising a total of 8 patients (16 eyes) with an age range of 7-34 years and a follow-up range of 4-48 months. Six case reports were included in this review, comprising a total of 8 patients (16 eyes) with an age range of 7-34 years and a follow-up range of 4-48 months. CONCLUSION: Evidence produced so far points out that refractive surgery may be an alternative for spectacle correction for adults with AET ≤10PD. There is not enough evidence to recommend its use for patients under 18 years of age. The safety and predictability of these procedures for this purpose remains unclear as the selection criteria used for these patients are much different than the usual indications and there are no studies with long-term follow-up.

Decoding epigenetic cell signaling in neuronal differentiation.

Neurogenesis is the process by which new neurons are generated in the brain. Neural stem cells (NSCs) are differentiated into neurons, which are integrated into the neural network. Nowadays, pluripotent stem cells, multipotent stem cells, and induced pluripotent stem cells can be artificially differentiated into neurons utilizing several techniques. Specific transcriptional profiles from NSCs during differentiation are frequently used to approach and observe phenotype alteration and functional determination of neurons. In this context, the role of non-coding RNA, transcription factors and epigenetic changes in neuronal development and differentiation has gained importance. Epigenetic elucidation has become a field of intense research due to distinct patterns of normal conditions and different neurodegenerative disorders, which can be explored to develop new diagnostic methods or gene therapies. In this review, we discuss the complexity of transcription factors, non-coding RNAs, and extracellular vesicles that are responsible for guiding and coordinating neural development.

The role of neurogenesis in neurorepair after ischemic stroke.

Stroke consists of an abrupt reduction of cerebral blood flow resulting in hypoxia that triggers an excitotoxicity, oxidative stress, and neuroinflammation. After the ischemic process, neural precursor cells present in the subventricular zone of the lateral ventricle and subgranular zone of the dentate gyrus proliferate and migrate towards the lesion, contributing to the brain repair. The neurogenesis is induced by signal transduction pathways, growth factors, attractive factors for neuroblasts, transcription factors, pro and anti-inflammatory mediators and specific neurotransmissions. However, this endogenous neurogenesis occurs slowly and does not allow a complete restoration of brain function. Despite that, understanding the mechanisms of neurogenesis could improve the therapeutic strategies for brain repair. This review presents the current knowledge about brain repair process after stroke and the perspectives regarding the development of promising therapies that aim to improve neurogenesis and its potential to form new neural networks.

OPTICAL COHERENCE TOMOGRAPHY AND OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY PARAMETERS IN PATIENTS WITH PHACOMATOSIS.

PURPOSE: To compare the retinal vasculature characteristics between eyes of patients with and without phacomatosis. METHODS: Case-control observational study with retinal vasculature evaluation by optical coherence tomography and optical coherence tomography angiography of the macula and disk. RESULTS: The study included 80 eyes. Neurofibromatosis Type 1 patients presented with a higher central macular thickness (P = 0.007), a lower optical disk nervous fiber layer (P = 0.006), a lower perimeter, area, and circularity of the foveal avascular zone (P < 0.05), a higher vascular density of macular avascular layer (AMVD) (P = 0.004), and a lower papillary vascular density of superficial capillary plexus (SPVD) (P = 0.048). Patients with tuberous sclerosis presented with an increase in central macular thickness (P = 0.024) and in vascular densities (P < 0.05) [except for macular vascular density of deep capillary plexus (PMVD), AMVD, and SPVD]. Patients with Sturge-Weber syndrome showed a decrease in optical disk nervous fiber layer (P < 0.001), subfoveal choroid thickness (P = 0.011), macular vascular density of superficial capillary plexus (SMVD) (P = 0.036), and SPVD (P < 0.001). CONCLUSION: Phacomatosis patients showed statistically significant differences of retinal vasculature characteristics, compared to eyes without pathology. Further studies are needed to determine when and if these parameters change with the course of the disease and if they can be used as biomarkers for disease severity or progression.

First detection of Gongylonema species in Geotrupes mutator in Europe.

The detection of three Gongylonema sp. infective larvae in two specimens of the dung beetle Geotrupes mutator (Marsham, 1802) from western Spain is reported here for the first time in Europe. Scanning electron microscopy confirmed that the analyzed specimens belong to the genus Gongylonema, but it was not possible to determine the species identity by the lack of morphological information in the literature and because many of the phenotypic characteristics had not yet fully developed at this juvenile stage. Nevertheless, a phylogenetic analysis using amplified cox1 nucleotide sequences has revealed that the studied larvae could be clearly discriminated (< 89% identity) from all the other Gongylonema cox1 sequences available in public genetic databases. While our results are limited by the scarcity of genetic information available for this genus, the possibility that the analyzed specimens might correspond to a new species should not be ruled out, and more studies are needed. The results provided in this report indicate that G. mutator is involved in the transmission cycle of Gongylonema sp. to vertebrates in Europe.

A survey of RNA viruses in mosquitoes from Mozambique reveals novel genetic lineages of flaviviruses and phenuiviruses, as well as frequent flavivirus-like viral DNA forms in Mansonia.

BACKGROUND: Mosquito-borne diseases involving arboviruses represent expanding threats to sub-Saharan Africa imposing as considerable burden to human and veterinary public health. In Mozambique over one hundred species of potential arbovirus mosquito vectors have been identified, although their precise role in maintaining such viruses in circulation in the country remains to be elucidated. The aim of this study was to screen for the presence of flaviviruses, alphaviruses and bunyaviruses in mosquitoes from different regions of Mozambique. RESULTS: Our survey analyzed 14,519 mosquitoes, and the results obtained revealed genetically distinct insect-specific flaviviruses, detected in multiple species of mosquitoes from different genera. In addition, smaller flavivirus-like NS5 sequences, frequently detected in Mansonia seemed to correspond to defective viral sequences, present as viral DNA forms. Furthermore, three lineages of putative members of the Phenuiviridae family were also detected, two of which apparently corresponding to novel viral genetic lineages. CONCLUSION: This study reports for the first-time novel insect-specific flaviviruses and novel phenuiviruses, as well as frequent flavivirus-like viral DNA forms in several widely known vector species. This unique work represents recent investigation of virus screening conducted in mosquitoes from Mozambique and an important contribution to inform the establishment of a vector control program for arbovirus in the country and in the region.

Decoding resistant hypertension signalling pathways.

Resistant hypertension (RH) is a clinical condition in which the hypertensive patient has become resistant to drug therapy and is often associated with increased cardiovascular morbidity and mortality. Several signalling pathways have been studied and related to the development and progression of RH: modulation of sympathetic activity by leptin and aldosterone, primary aldosteronism, arterial stiffness, endothelial dysfunction and variations in the renin-angiotensin-aldosterone system (RAAS). miRNAs comprise a family of small non-coding RNAs that participate in the regulation of gene expression at post-transcriptional level. miRNAs are involved in the development of both cardiovascular damage and hypertension. Little is known of the molecular mechanisms that lead to development and progression of this condition. This review aims to cover the potential roles of miRNAs in the mechanisms associated with the development and consequences of RH, and explore the current state of the art of diagnostic and therapeutic tools based on miRNA approaches.

First molecular detection of Leishmania tarentolae-like DNA in Sergentomyia minuta in Spain.

Phlebotomine sand flies (Diptera, Psychodidae) are vectors of multiple Leishmania species, among which Leishmania infantum stands out as a being frequently pathogenic to humans and dogs in Mediterranean countries. In this study, Sergentomyia minuta sand flies were collected using CDC miniature light traps in different 431 biotopes from Southwest Spain. A total of 114 females were tested for the presence of Leishmania DNA by targeting ITS-1 and cyt-B sequences by PCR. Leishmania DNA was detected in one S. minuta. Characterization of the obtained DNA sequences by phylogenetic analyses revealed close relatedness with Leishmania tarentolae Wenyon, 1921 as well as with both human and canine pathogenic strains of Asian origin (China), previously described as Leishmania sp. To our knowledge, this is the first report of phlebotomine sand flies naturally infected with L. tarentolae-like in Spain. The possible infection of sand flies with novel Leishmania species should be taken into consideration in epidemiological studies of vector species in areas where leishmaniosis is endemic.

Human adult stem cells from diverse origins: an overview from multiparametric immunophenotyping to clinical applications.

Stem cells are known for their capacity to self-renew and differentiate into at least one specialized cell type. Mesenchymal stem cells (MSCs) were isolated initially from bone marrow but are now known to exist in all vascularized organ or tissue in adults. MSCs are particularly relevant for therapy due to their simplicity of isolation and cultivation. The International Society for Cellular Therapy (ISCT) has proposed a set of standards to define hMSCs for laboratory investigations and preclinical studies: adherence to plastic in standard culture conditions; in vitro differentiation into osteoblasts, adipocytes, and chondroblasts; specific surface antigen expression in which ≥95% of the cells express the antigens recognized by CD105, CD73, and CD90, with the same cells lacking (≤2% positive) the antigens CD45, CD34, CD14 or CD11b, CD79a or CD19, and HLA-DR. In this review we will take an historical overview of how umbilical cord blood, bone marrow, adipose-derived, placental and amniotic fluid, and menstrual blood stem cells, the major sources of human MSC, can be obtained, identified and how they are being used in clinical trials to cure and treat a very broad range of conditions, including heart, hepatic, and neurodegenerative diseases. An overview of protocols for differentiation into hepatocytes, cardiomyocytes, neuronal, adipose, chondrocytes, and osteoblast cells are highlighted. We also discuss a new source of stem cells, induced pluripotent stem cells (iPS cells) and some pathways, which are common to MSCs in maintaining their pluripotent state.

The Visual Impairment of Inherited Retinal Diseases in Portugal as per the National Table of Disabilities.

Purpose: To evaluate the visual impairment of patients with inherited retinal diseases (IRDs), as per the national table of disabilities (TNI). Design: Retrospective, single-center cohort study. Participants: Patients with a clinical diagnosis of IRD were recruited at a referral center in Portugal. Methods: Demographics and clinical data were collected from each individual patient file. The estimated visual disability coefficient was calculated through the evaluation of 7 graduated categories: orbital or eyelid deformities, low vision, visual field change, loss of bi-foveolar fixation, oculomotor palsy, photophobia, and chronic conjunctivitis. The TNI provides minimum and maximum disability values for numerous conditions within each category, which were summed to calculate an overall summary disability coefficient for each patient. Main Outcome Measures: Demographic/clinical and estimated minimum and maximum visual disability coefficient according to the TNI for each patient. Results: This study included 253 patients from 214 families, aged 3 to 80 years, with a mean age of 39.8 ± 20.0 years. The mean estimated minimum and maximum visual disability coefficients as per the TNI were 0.6 ± 0.4 and 0.7 ± 0.4, respectively. The low vision was the single most frequent contributor category (21.7%) present in the calculation of visual impairment. Low vision and visual field changes were the most frequent double combination (18.2%), and the addition of loss of bi-foveolar fixation was the most frequent triple combination (8.3%). Conclusions: This study found that IRD patients had a significant visual disability, with the majority having a disability coefficient ≥0.6, which would qualify them for a "multipurpose disability medical certificate." Financial Disclosures: The authors have no proprietary or commercial interest in any materials discussed in this article.

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.

Description of New Morphological Variation of Culex (Culex) coronator Dyar and Knab, 1906 and First Report of Culex (Carrollia) bonnei Dyar, 1921 Found in the Central Region of Peru.

Mosquitoes (Diptera: Culicidae) pose a significant threat to public health worldwide, especially in tropical and subtropical regions, where they act as primary vectors in transmission of infectious agents. In Peru, 182 culicid species have been identified and several species of the genus Culex are known to transmit arboviruses. However, knowledge of mosquito diversity and distribution remains limited, with many studies focusing on specific regions only. Here, we describe a new morphological variation of Cx. (Culex) coronator Dyar and Knab, 1906, and report the presence of Culex (Carrollia) bonnei Dyar, 1921 in the central region of Peru, Huanuco. Specimens were obtained through larvae collections and identified through morphologic characterization, including dissection of male genitalia, and molecular analyses. In total, 17 mosquitoes were analyzed, and the genitalia of the male specimens allowed the identification of Cx. coronator and Cx. bonnei. Partial sequences of the CoxI gene corresponding to these two species were obtained (N = 10). Phylogenetic analysis revealed that the sequences of Cx. coronator grouped in a monophyletic clade with sequences ascribed to other species corresponding to the subgenus Carrollia, while Cx. bonnei specimens formed a monophyletic clade with homologous sequences from GenBank. This study underscores the importance of continued efforts to study the diversity and distribution of mosquitoes in Peru, including their potential role as vectors of human pathogens, to underpin effective disease control and prevention strategies, highlighting the importance of a complemented morphological and molecular analysis.

The socioeconomic epidemiology of inherited retinal diseases in Portugal.

BACKGROUND: Inherited retinal diseases (IRDs) are a group of rare degenerative disorders of the retina that can lead to blindness from birth to late middle age. Knowing the target population and its resources is essential to better plan support measures. The aim of this study was to evaluate the socioeconomic characteristics of regions in Portugal where IRD patients reside to inform the planning of vision aid and rehabilitation intervention measures. RESULTS: This study included 1082 patients from 973 families, aged 3 to 92 years, with a mean age of 44.8 ± 18.1 years. Patients living with an IRD were identified in 190 of the 308 municipalities. According to this study, the estimated IRD prevalence in Portugal was 10.4 per 100,000 inhabitants, and by municipalities, it ranged from 0 to 131.2 per 100,000 inhabitants. Overall, regions with a higher prevalence of IRD have a lower population density (r=-0.371, p < 0.001), a higher illiteracy rate (r = 0.404, p < 0.001) and an overall older population (r = 0.475, p < 0.001). Additionally, there is a lower proportion of doctor per capita (r = 0.350, p < 0.001), higher social security pensions beneficiaries (r = 0.439, p < 0.001), worse water quality for human consumption (r=-0.194, p = 0.008), fewer audiences at the cinema (r=-0.315, p < 0.001) and lower proportion of foreign guests in tourist accommodations (r=-0.287, p < 0.001). CONCLUSION: The number of identified patients with IRD varied between regions. Using data from national statistics (PORDATA), we observed differences in socioeconomic characteristics between regions. Multiple targeted aid strategies can be developed to ensure that all IRD patients are granted full clinical and socioeconomic support.

Characterization of an insect-specific flavivirus (OCFVPT) co-isolated from Ochlerotatus caspius collected in southern Portugal along with a putative new Negev-like virus.

We describe the isolation and characterization of an insect-specific flavivirus (ISF) from Ochlerotatus caspius (Pallas, 1771) mosquitoes collected in southern Portugal. The RNA genome of this virus, tentatively designated OCFVPT, for O. caspius flavivirus from Portugal, encodes a polyprotein showing all the features expected for a flavivirus. As frequently observed for ISF, the viral genomes seems to encode a putative Fairly Interesting Flavivirus ORF (FIFO)-like product, the synthesis of which would occur as a result of a -1 translation frameshift event. OCFVPT was isolated in the C6/36 Stegomyia albopicta (= Aedes albopictus) cell line where it replicates rapidly, but failed to replicate in Vero cells in common with other ISFs. Unlike some of the latter, however, the OCFVPT genome does not seem to be integrated in the mosquito cells we tested. Phylogenetic analyses based on partial ISF NS5 nucleotide sequences placed OCFVPT among recently published viral strains documented from mosquitoes collected in the Iberian Peninsula, while analyses of ORF/E/NS3/or NS5 amino acid sequences cluster OCFVPT with HANKV (Hanko virus), an ISF recently isolated from O. caspius mosquitoes collected in Finland. Taking into account the genetic relatedness with this virus, OCFVPT is not expected to be overtly cytopathic to C6/36 cells. The cytopathic effects associated with its presence in culture supernatants are postulated to be the result of the replication of a co-isolated putative new Negev-like virus.

Photoscreening for amblyopia risk factors assessment in young children: A systematic review with meta-analysis.

PURPOSE: Amblyopia is a leading cause of preventable and treatable vision loss in the pediatric population. Instrument-based screening of amblyopia-risk factors is being widely adopted but the audit of its results is still lacking. We sought to review the existing evidence regarding the outcomes of photoscreening applied to children under the age of three years. METHODS: A three-database search (Pubmed, ISI Web of Science, and Scopus) was performed from inception to March 2021. A meta-analysis of proportions was conducted to summarize the referral rate, untestable rate and positive predictive value (PPV). RESULTS: Thirteen studies were selected among 705 original abstracts. The quantitative analysis included twelve studies enrolling 64,041 children. Of these, 13% (95%CI: 7-19%) were referred for further confirmation of the screening result. Astigmatism was the most common diagnosis both after screening and after ophthalmologic assessment of referred children. The pooled untestable rate and PPV were 8% (95%CI: 3-15%) and 56% (95%CI: 40-71%), respectively. CONCLUSION: There is no global consensus on the optimal age, frequency or what magnitude of refractive error must be considered an amblyopia-risk factor. Optimization of referral criteria is therefore warranted.

Shedding light on the controversial taxonomic status of Culicoides jamaicensis and Culicoides paolae (Diptera: Ceratopogonidae): an overseas trip among continents.

Culicoides biting midges (Diptera: Ceratopogonidae) are small bloodsucking flies that act as vectors for various pathogens of medical and veterinary importance. This study aimed to examine, using a comprehensive approach, the controversial taxonomic status of 2 Culicoides species that are currently distributed in the Neotropical (Culicoides jamaicensis Edwards) and Palearctic (Culicoides paolae Boorman) areas and possess unique and distinctive features. Previous investigations based on morphological analysis have suggested that these 2 species may be synonyms. Our work updated the current geographical distribution of both species and analyzed new specimens from different geographic origins, together with publicly available sequences. We used 2 universal genetic markers (COI and 28S) to test this hypothesis. Our study reveals evidence that C. paolae and C. jamaicensis belong to the same species due to the following statements: (i) similar morphological features; (ii) low interspecific genetic variation; (iii) association with a single genetic cluster; (iv) inclusion within the subgenus Drymodesmyia, which has only been recorded in the New World; and (v) occurrence in habitats with moderate temperatures. We recommend that European and African specimens of C. paolae be considered from now on as C. jamaicensis. Our comprehensive approach shed new light on the taxonomic status of these 2 Culicoides species and has implications for future studies on their biology and ecology.

The Impact of Early Photoscreening on Medium-term Visual Acuity: A Population-Based Study.

PURPOSE: To analyze the outcomes of an early ophthalmological intervention in children included in the pilot project of the "Rastreio de Saúde Visual Infantil" (RSVI) visual screening program in Portugal. METHODS: This was a retrospective analysis of the medical records of all children included in the RSVI from April 1, 2016 to December 31, 2016, and who were referred to an ophthalmology appointment. Data of refractive errors, anisometropia, amblyopia, instituted treatments, and visual acuity at the end of the ophthalmological intervention were collected. RESULTS: Two hundred sixty-seven (18.2%) 2-year-old children from the Centro Hospitalar Universitário do Porto reference area had a positive screening result and were subsequently referred to an ophthalmology appointment. Glasses were prescribed to 31.1% of the patients who attended. Presumed amblyopia was diagnosed in 2.5% and occlusion was prescribed. At the end of a median follow-up of 3 years, of those who wore glasses without occlusion, 94.3% had a visual acuity of 20/25 or better in both eyes with an asymmetry of two lines or less between eyes. Of the 4 children who wore glasses with occlusion, 3 of them had a visual acuity of 20/25 or better in both eyes with an asymmetry of two lines or less between eyes. CONCLUSIONS: This study demonstrates the effectiveness of an early intervention in the prevention and treatment of amblyopia, because after a median follow-up of 3 years after treatment none of the referred children met criteria for amblyopia and 94.3% of the referred children who had an intervention had a normal visual acuity. [J Pediatr Ophthalmol Strabismus. 2023;60(3):178-183.].