TypeTaxonScript: sugarifying and enhancing data structures in biological systematics and biodiversity research.

Object-oriented programming (OOP) embodies a software development paradigm grounded in representing real-world entities as objects, facilitating a more efficient and structured modelling approach. In this article, we explore the synergy between OOP principles and the TypeScript (TS) programming language to create a JSON-formatted database designed for storing arrays of biological features. This fusion of technologies fosters a controlled and modular code script, streamlining the integration, manipulation, expansion, and analysis of biological data, all while enhancing syntax for improved human readability, such as through the use of dot notation. We advocate for biologists to embrace Git technology, akin to the practices of programmers and coders, for initiating versioned and collaborative projects. Leveraging the widely accessible and acclaimed IDE, Visual Studio Code, provides an additional advantage. Not only does it support running a Node.js environment, which is essential for running TS, but it also efficiently manages GitHub versioning. We provide a use case involving taxonomic data structure, focusing on angiosperm legume plants. This method is characterized by its simplicity, as the tools employed are both fully accessible and free of charge, and it is widely adopted by communities of professional programmers. Moreover, we are dedicated to facilitating practical implementation and comprehension through a comprehensive tutorial, a readily available pre-built database at GitHub, and a new package at npm.

Unveiling breast cancer metastasis through an advanced X-ray imaging approach.

Breast cancer is a significant global health burden, causing a substantial number of deaths. Systemic metastatic tumour cell dissemination is a major cause of poor outcomes. Understanding the mechanisms underlying metastasis is crucial for effective interventions. Changes in the extracellular matrix play a pivotal role in breast cancer metastasis. In this work, we present an advanced multimodal X-ray computed tomography, by combining Small-angle X-ray Scattering Tensor Tomography (SAXS-TT) and X-ray Fluorescence Computed Tomography (XRF-CT). This approach likely brings out valuable information about the breast cancer metastasis cascade. Initial results from its application on a breast cancer specimen reveal the collective influence of key molecules in the metastatic mechanism, identifying a strong correlation between zinc accumulation (associated with matrix metalloproteinases MMPs) and highly oriented collagen. MMPs trigger collagen alignment, facilitating breast cancer cell intravasation, while iron accumulation, linked to angiogenesis and vascular endothelial growth factor VEGF, supports cell proliferation and metastasis. Therefore, these findings highlight the potential of the advanced multimodal X-ray computed tomography approach and pave the way for in-depth investigation of breast cancer metastasis, which may guide the development of novel therapeutic approaches and enable personalised treatment strategies, ultimately improving patient outcomes in breast cancer management.

Linking centennial scale anthropogenic changes and sedimentary records as lessons for urban coastal management.

Coastal eutrophication and urban flooding are increasingly important components of global change. Although increased seawater renewal by barrier openings and channelizing are common mitigation measures in coastal lagoons worldwide, their effects on these ecosystems are not fully understood. Here, we evaluated the relationships between human interventions in the watershed, artificial connections to the sea, and the sediment burial rates in an urban coastal lagoon (Maricá lagoon, Southeastern Brazil). Sediment accretion along with nutrient and carbon burial rates were determined in two sediment cores representing the past ∼120 years (210Pb dating) and associated with anthropogenic changes as indicated by historical records and geoinformation analyses. Lagoon infilling and eutrophication, expressed by the average sediment accretion, TP, TN, and OC burial rates, respectively, increased ∼9-18, 13-15, 11-14 and 11-12-fold from the earliest (<1950) to the most recent (2000-2017) period. These multi-proxy records confirm mechanistic links between deforestation, urbanization, and untreated sewage discharges. In addition, our findings reveal artificial connections to the sea may contribute to lagoonal eutrophication and infilling, particularly when not integrated with sewage treatment and forest conservation or reforestation in the watershed. Therefore, increased seawater renewal by physical interventions commonly considered as mitigation measures may in contrast cause severe degradation in coastal lagoons, causing harmful consequences that should be not neglected when implementing management practices.

Strong Dispersal Limitation of Microbial Communities at Shackleton Glacier, Antarctica.

Microbial communities can be structured by both deterministic and stochastic processes, but the relative importance of these processes remains unknown. The ambiguity partly arises from an inability to disentangle soil microbial processes from confounding factors, such as aboveground plant communities or anthropogenic disturbance. In this study, we characterized the relative contributions of determinism and stochasticity to assembly processes of soil bacterial communities across a large environmental gradient of undisturbed Antarctic soils. We hypothesized that harsh soils would impose a strong environmental selection on microbial communities, whereas communities in benign soils would be structured largely by dispersal. Contrary to our expectations, dispersal was the dominant assembly mechanism across the entire soil environmental gradient, including benign environments. The microbial community composition reflects slowly changing soil conditions and dispersal limitation of isolated sites. Thus, stochastic processes, as opposed to deterministic, are primary drivers of soil ecosystem assembly across space at our study site. This is especially surprising given the strong environmental constraints on soil microorganisms in one of the harshest environments on the planet, suggesting that dispersal could be a driving force in microbial community assembly in soils worldwide. IMPORTANCE Because of their diversity and ubiquity, microbes provide an excellent means to tease apart how natural communities are structured. In general, ecologists believe that stochastic assembly processes, like random drift and dispersal, should dominate in benign environments while deterministic processes, like environmental filtering, should be prevalent in harsh environments. To help resolve this debate, we analyzed microbial community composition in pristine Antarctic soils devoid of human influence or plant communities for eons. Our results demonstrate that dispersal limitation is a surprisingly potent force of community limitation throughout all soil conditions. Thus, dispersal appears to be a driving force of microbial community assembly, even in the harshest of conditions.

The butterflies (Lepidoptera, Papilionoidea) of the Parque Estadual Intervales and surroundings, São Paulo, Brazil / As borboletas (Lepidoptera, Papilionoidea) do Parque Estadual Intervales e arredores, São Paulo, Brasil

Abstract The Global South has witnessed increasing sampling of its immense biological diversity during the past century. However, the diversity of many regions remains unknown, even at pristine and highly threatened places, such as in the Atlantic Forest; and for bioindicator, umbrella, and flagship groups. The present study reports the first butterfly list of the Parque Estadual Intervales, São Paulo, Brazil and surroundings, a key protected area in the last massive continuous of the Atlantic Forest. We compiled data from museums and four years of field work, under three sampling methods. We also aimed at providing resources to support conservation efforts by analyzing 27 years of climatic data (detailed in the Supplementary Material, in English and in Portuguese), discussing our results also for non-academics, and producing scientific outreach and educational material. A companion article dealt with the experiences of science outreach and capacity development, and illustrated the butterfly catalogue of the species sampled in the park. We found 312 species that sum to 2,139 records. The museum had 229 species (432 records), and we sampled 142 species (1,682 individuals), in a total effort of 36,679 sampling hours (36,432 trap and 247 net and observation hours). The richest families were Nymphalidae (148 species) and Hesperiidae (100 species). Most species were sampled exclusively by active methods (79.8%), but other sources (passive sampling, citizen science, etc.) also found unique records. We found the highest diversity metrics from January to May, and we demonstrated that winter months had less richness and abundance. We illustrated the 20 species common to all regions, and listed those that were found more than seven months in the year, as well as the most abundant species in trap sampling, with forest dwellers as well as species common to open and fragmented areas. The dominant species in our trap datasets was the iridescent white morpho, Morpho epistrophus (Fabricius, 1796), and we suggest it to become the park butterfly mascot.

Resumo O Sul Global testemunhou crescente amostragem de sua imensa diversidade biológica durante o século passado. Entretanto, a diversidade de muitas regiões permanece desconhecida, mesmo em locais pristinos e altamente ameaçados, como na Mata Atlântica; e para grupos bioindicadores, guarda-chuva e emblemáticos. O presente estudo reporta a primeira lista de borboletas do Parque Estadual Intervales, São Paulo, Brasil e arredores, uma unidade de conservação chave no último maciço contínuo de Mata Atlântica. Compilamos dados de museus e quatro anos de campo, sob três métodos de amostragem. Também visamos oferecer recursos para apoiar os esforços de conservação, analisando 27 anos de dados climáticos (detalhados no Material Suplementar, em inglês e em português), discutindo nossos resultados numa linguagem também para não acadêmicos, e produzindo material de divulgação científica e educativos. Um artigo irmão tratou das experiências de divulgação científica e capacitação, e ilustrou o catálogo de borboletas das espécies amostradas no parque. Encontramos 312 espécies em 2.139 registros. O museu tinha 229 espécies (432 registros), e amostramos 142 espécies (1.682 indivíduos), em um esforço total de 36.679 horas de amostragem (36.432 armadilhas e 247 horas de rede e observação). As famílias mais ricas foram Nymphalidae (148 espécies) e Hesperiidae (100 espécies). A maioria das espécies foi amostrada exclusivamente por métodos ativos (79,8%), mas outras fontes (passiva, ciência cidadã, etc.) também encontraram registros únicos. Encontramos as maiores métricas de diversidade de janeiro a maio, e demonstramos que os meses de inverno tiveram menos riqueza e abundância. Ilustramos as 20 espécies comuns a todas as regiões, e listamos aquelas que foram encontradas em mais de sete meses no ano, bem como as espécies mais abundantes em armadilhas, com espécies florestais e também comuns em áreas abertas e fragmentadas. A espécie dominante em nossas armadilhas foi a morfo branca iridescente, Morpho epistrophus (Fabricius, 1796), e sugerimos que se torne a borboleta mascote do parque.

Emotional Stability and Anxiety Symptoms Differentiates People Leaving the Home Usually During the Covid-19 Pandemic.

Objective: The population's adhesion to measures to ensure social distancing represents a great management challenge in a pandemic context. Despite of evidence shown that social distancing is effective, lack of adherence still persists in many countries. Therefore, it is challenging to separate the effectiveness of government measures, from social distancing driven by personal initiatives. Theory: It is possible that the output of protective behaviors, such as adherence to protective measures and staying in social isolation, is influenced by individual characteristics, such as personality traits or symptoms of mental distress of anxiogenic nature. We hypothesized that individuals with more expressive symptoms of fear or anxiety would have a more protective behavioral tendency in terms of risk exposure, leaving less home during the pandemic. In contrast, individuals with greater emotional stability, as they feel more secure and with a lower perception of risk, could go out more often. Method: A total of 2709 individuals from all regions of Brazil participated in the study (mean age = 42 years; 2134 women). Correlation analysis was performed to investigate the relationships between personality traits according to the big five model and Psychopathological Symptoms (BSI). Then, correlation analysis was performed to investigate how people that go out often differ from people that stay at home, in both symptoms and personality traits. Finally, to investigate the predictors for going out usually, we use multiple regression analysis, using gender, marital status, level of education, and personality traits. Results: During the second wave of COVID-19 in Brazil, individuals with higher emotional stability tended to leave home more than those with more expressive levels of anxiogenic dysregulation. These results reinforce the role of both personality traits and psychopathological symptoms in prophylactic behavior during COVID-19 pandemics. Conclusions: Individuals with greater emotional stability were more likely to leave home during the second wave of COVID-19 than those with higher levels of anxiogenic dysregulation.

Response of Antarctic soil fauna to climate-driven changes since the Last Glacial Maximum.

Understanding how terrestrial biotic communities have responded to glacial recession since the Last Glacial Maximum (LGM) can inform present and future responses of biota to climate change. In Antarctica, the Transantarctic Mountains (TAM) have experienced massive environmental changes associated with glacial retreat since the LGM, yet we have few clues as to how its soil invertebrate-dominated animal communities have responded. Here, we surveyed soil invertebrate fauna from above and below proposed LGM elevations along transects located at 12 features across the Shackleton Glacier region. Our transects captured gradients of surface ages possibly up to 4.5 million years and the soils have been free from human disturbance for their entire history. Our data support the hypothesis that soils exposed during the LGM are now less suitable habitats for invertebrates than those that have been exposed by deglaciation following the LGM. Our results show that faunal abundance, community composition, and diversity were all strongly affected by climate-driven changes since the LGM. Soils more recently exposed by the glacial recession (as indicated by distances from present ice surfaces) had higher faunal abundances and species richness than older exposed soils. Higher abundances of the dominant nematode Scottnema were found in older exposed soils, while Eudorylaimus, Plectus, tardigrades, and rotifers preferentially occurred in more recently exposed soils. Approximately 30% of the soils from which invertebrates could be extracted had only Scottnema, and these single-taxon communities occurred more frequently in soils exposed for longer periods of time. Our structural equation modeling of abiotic drivers highlighted soil salinity as a key mediator of Scottnema responses to soil exposure age. These changes in soil habitat suitability and biotic communities since the LGM indicate that Antarctic terrestrial biodiversity throughout the TAM will be highly altered by climate warming.

Precipitation effects on nematode diversity and carbon footprint across grasslands.

Free-living nematodes are one of the most diverse metazoan taxa in terrestrial ecosystems and are critical to the global soil carbon (C) cycling through their role in organic matter decomposition. They are highly dependent on water availability for movement, feeding, and reproduction. Projected changes in precipitation across temporal and spatial scales will affect free-living nematodes and their contribution to C cycling with unforeseen consequences. We experimentally reduced and increased growing season precipitation for 2 years in 120 field plots at arid, semiarid, and mesic grasslands and assessed precipitation controls on nematode genus diversity, community structure, and C footprint. Increasing annual precipitation reduced nematode diversity and evenness over time at all sites, but the mechanism behind these temporal responses differed for dry and moist grasslands. In arid and semiarid sites, there was a loss of drought-adapted rare taxa with increasing precipitation, whereas in mesic conditions increases in the population of predaceous taxa with increasing precipitation may have caused the observed reductions in dominant colonizer taxa and yielded the negative precipitation-diversity relationship. The effects of temporal changes in precipitation on all aspects of the nematode C footprint (respiration, production, and biomass C) were all dependent on the site (significant spatial × temporal precipitation interaction) and consistent with diversity responses at mesic, but not at arid and semiarid, grasslands. These results suggest that free-living nematode biodiversity and their C footprint will respond to climate change-driven shifts in water availability and that more frequent extreme wet years may accelerate decomposition and C turnover in semiarid and arid grasslands.

The genomic prehistory of the Indigenous peoples of Uruguay.

The prehistory of the people of Uruguay is greatly complicated by the dramatic and severe effects of European contact, as with most of the Americas. After the series of military campaigns that exterminated the last remnants of nomadic peoples, Uruguayan official history masked and diluted the former Indigenous ethnic diversity into the narrative of a singular people that all but died out. Here, we present the first whole genome sequences of the Indigenous people of the region before the arrival of Europeans, from an archaeological site in eastern Uruguay that dates from 2,000 years before present. We find a surprising connection to ancient individuals from Panama and eastern Brazil, but not to modern Amazonians. This result may be indicative of a migration route into South America that may have occurred along the Atlantic coast. We also find a distinct ancestry previously undetected in South America. Though this work begins to piece together some of the demographic nuance of the region, the sequencing of ancient individuals from across Uruguay is needed to better understand the ancient prehistory and genetic diversity that existed before European contact, thereby helping to rebuild the history of the Indigenous population of what is now Uruguay.

Early-diverging fungal phyla: taxonomy, species concept, ecology, distribution, anthropogenic impact, and novel phylogenetic proposals.

The increasing number of new fungal species described from all over the world along with the use of genetics to define taxa, has dramatically changed the classification system of early-diverging fungi over the past several decades. The number of phyla established for non-Dikarya fungi has increased from 2 to 17. However, to date, both the classification and phylogeny of the basal fungi are still unresolved. In this article, we review the recent taxonomy of the basal fungi and re-evaluate the relationships among early-diverging lineages of fungal phyla. We also provide information on the ecology and distribution in Mucoromycota and highlight the impact of chytrids on amphibian populations. Species concepts in Chytridiomycota, Aphelidiomycota, Rozellomycota, Neocallimastigomycota are discussed in this paper. To preserve the current application of the genus Nephridiophaga (Chytridiomycota: Nephridiophagales), a new type species, Nephridiophaga blattellae, is proposed.

X-ray-Based Techniques to Study the Nano-Bio Interface.

X-ray-based analytics are routinely applied in many fields, including physics, chemistry, materials science, and engineering. The full potential of such techniques in the life sciences and medicine, however, has not yet been fully exploited. We highlight current and upcoming advances in this direction. We describe different X-ray-based methodologies (including those performed at synchrotron light sources and X-ray free-electron lasers) and their potentials for application to investigate the nano-bio interface. The discussion is predominantly guided by asking how such methods could better help to understand and to improve nanoparticle-based drug delivery, though the concepts also apply to nano-bio interactions in general. We discuss current limitations and how they might be overcome, particularly for future use in vivo.

Effects of dietary fibre intake in chemotherapy-induced mucositis in murine model.

Mucositis is an inflammation of the gastrointestinal mucosa resulting from high doses of radio/chemotherapy treatment and may lead to interruption of antineoplasic therapy. Soluble fibres, like pectin, increase SCFA production, which play a role in gut homoeostasis and inflammation suppression. Due to the properties of pectin, the aim of the present study was to evaluate the effect of a high-fibre (HF) diet on chemotherapy-induced mucositis in a murine model. C57/BL6 mice received control (AIN93M), HF, low/zero fibre (LF) diets for 10 d prior to mucositis challenging with irinotecan (75 mg/kg), or they were treated with acetate added to drinking water 5 d prior to and during the mucositis induction. Mice that received the HF diet showed decreased immune cells influx and improved histopathological parameters in the intestine, compared with mice that received the normal diet. Furthermore, the HF diet decreased intestinal permeability induced in the mucositis model when compared with the control group. This effect was not observed for acetate alone, which did not improve gut permeability. For instance, mice that received the LF diet had worsened gut permeability, compared with mice that received the normal diet and mucositis. The effects of the HF and LF diets were shown to modulate the intestinal microbiota, in which the LF diet increased the levels of Enterobacteriaceae, a group associated with gut inflammation, whereas the HF diet decreased this group and increased Lactobacillus and Bifidobacterium (SCFA producers) levels. In conclusion, the results demonstrated the importance of dietary fibre intake in the modulation of gut microbiota composition and homoeostasis maintenance during mucositis in this model.

Ecto- and endoparasitic nematodes respond differently across sites to changes in precipitation.

Plant parasitic nematodes are among the greatest consumers of primary production in terrestrial ecosystems. Their feeding strategies can be divided into endoparasites and ectoparasites that differ substantially, not only in their damage potential to host tissue and primary production, but also in their susceptibility to environmental changes. Climate change is predicted to increase variability of precipitation in many systems, yet the effects on belowground biodiversity and associated impacts on primary productivity remain poorly understood. To examine the impact of altered precipitation on endo- and ectoparasitic soil nematodes, we conducted a 2-year precipitation manipulation study across an arid, a semiarid, and a mesic grassland. Plant parasite feeding type abundance, functional guilds, and herbivory index in response to precipitation were evaluated. Responses of endo- and ectoparasites to increased precipitation varied by grassland type. There was little response of ectoparasites to increased precipitation although their population declined at the mesic site with increased precipitation. The abundance of endoparasites remained unchanged with increasing precipitation at the arid site, increased at the semiarid, and decreased at the mesic site. The herbivory index followed closely the trends seen in the endoparasites response by stagnating at the arid site, increasing at the semiarid, and decreasing at the mesic site. Our findings suggest that altered precipitation has differing effects on plant parasite feeding strategies as well as functional guilds. This may have important implications for grassland productivity, as plant parasite pressure may exacerbate the effects of climate change on host plants.

A new species of the Neotropical loricariid Hypostomus cochliodon group (Hypostominae) from the lower Rio Tapajós basin, Brazilian Amazon.

A new species of Hypostomus with spoon-shaped teeth is described from the Rio Cupari basin, a right margin affluent of the lower Rio Tapajós, Pará State, Brazil. The new species inhabits rocky bottom areas in the main channel of Rio Cupari and its tributaries. The new species can be distinguished from all its congeners, except from the Hypostomus cochliodon group, by having six to eight spoon-shaped teeth, dentaries angled at less than 80° and the absence of a notch between the hyomandibular and the metapterygoid. The new species is distinguished from all species of the H. cochliodon group by its unique colour pattern, containing dark vermiculations on head and anterior portion of the trunk, and by the absence of medial buccal papillae.

Novel Mucoralean Fungus From a Repugnant Substrate: Mucor merdophylus sp. nov., Isolated From Dog Excrement.

The repeated observation of dog dung covered by abundant white cottony mycelium in a private garden in the city of Rio de Janeiro, state of Rio de Janeiro (Brazil) prompted an investigation to clarify the identity of the fungus involved. Three different species of mucoralean fungi (together with some ascomycete asexual morphs) were present. Two were identified as belonging to Mycotypha sp. and Thamnostylum sp., and the third belonged to Mucor sp. This publication deals with the full taxonomic elucidation of the latter. Based on morphological, physiological, and molecular data (ITS and LSU rDNA regions), it was recognized that this Mucor differed from all other species. It produces strongly sympodially circinate branched sporangiophores (some with up to four septa) with numerous swellings resembling abortive sporangia. It also has cylindrical, obovoid, pyriform, or ovoid columellae and its sporangiospores are mostly ellipsoid, although some are subglobose and others are irregular. Based on the evidence of the analyzed datasets, the new species Mucor merdophylus is hereby proposed.

Pharmacokinetic Parameters of HIV-1 Protease Inhibitors.

Since the beginning of the HIV epidemic, research has been carried out to control the virus. Understanding the mechanisms of replication has given access to the various classes of drugs that over time have transformed AIDS into a manageable chronic disease. The class of protease inhibitors (PIs) gained notice in anti-retroviral therapy, once it was found that peptidomimetic molecules act by blocking the active catalytic center of the aspartic protease, which is directly related to HIV maturation. However, mutations in enzymatic internal residues are the biggest issue for these drugs, because a small change in biochemical interaction can generate resistance. Low plasma concentrations of PIs favor viral natural selection; high concentrations can inhibit even partially resistant enzymes. Food-drug/drug-drug interactions can decrease the bioavailability of PIs and are related to many side effects. Therefore, this review summarizes the pharmacokinetic properties of current PIs, the changes when pharmacological boosters are used and also lists the major mutations to help understanding of how long the continuous treatment can ensure a low viral load in patients.

A database of freshwater fish species of the Amazon Basin.

The Amazon Basin is an unquestionable biodiversity hotspot, containing the highest freshwater biodiversity on earth and facing off a recent increase in anthropogenic threats. The current knowledge on the spatial distribution of the freshwater fish species is greatly deficient in this basin, preventing a comprehensive understanding of this hyper-diverse ecosystem as a whole. Filling this gap was the priority of a transnational collaborative project, i.e. the AmazonFish project - https://www.amazon-fish.com/. Relying on the outputs of this project, we provide the most complete fish species distribution records covering the whole Amazon drainage. The database, including 2,406 validated freshwater native fish species, 232,936 georeferenced records, results from an extensive survey of species distribution including 590 different sources (e.g. published articles, grey literature, online biodiversity databases and scientific collections from museums and universities worldwide) and field expeditions conducted during the project. This database, delivered at both georeferenced localities (21,500 localities) and sub-drainages grains (144 units), represents a highly valuable source of information for further studies on freshwater fish biodiversity, biogeography and conservation.

Mapping Atlantic rainforest degradation and regeneration history with indicator species using convolutional network.

The Atlantic rainforest of Brazil is one of the global terrestrial hotspots of biodiversity. Despite having undergone large scale deforestation, forest cover has shown signs of increases in the last decades. Here, to understand the degradation and regeneration history of Atlantic rainforest remnants near São Paulo, we combine a unique dataset of very high resolution images from Worldview-2 and Worldview-3 (0.5 and 0.3m spatial resolution, respectively), georeferenced aerial photographs from 1962 and use a deep learning method called U-net to map (i) the forest cover and changes and (ii) two pioneer tree species, Cecropia hololeuca and Tibouchina pulchra. For Tibouchina pulchra, all the individuals were mapped in February, when the trees undergo mass-flowering with purple and pink blossoms. Additionally, elevation data at 30m spatial resolution from NASA Shuttle Radar Topography Mission (SRTM) and annual mean climate variables (Terraclimate datasets at ∼ 4km of spatial resolution) were used to analyse the forest and species distributions. We found that natural forests are currently more frequently found on south-facing slopes, likely because of geomorphology and past land use, and that Tibouchina is restricted to the wetter part of the region (southern part), which annually receives at least 1600 mm of precipitation. Tibouchina pulchra was found to clearly indicate forest regeneration as almost all individuals were found within or adjacent to forests regrown after 1962. By contrast, Cecropia hololeuca was found to indicate older disturbed forests, with all individuals almost exclusively found in forest fragments already present in 1962. At the regional scale, using the dominance maps of both species, we show that at least 4.3% of the current region's natural forests have regrown after 1962 (Tibouchina dominated, ∼ 4757 ha) and that ∼ 9% of the old natural forests have experienced significant disturbance (Cecropia dominated).

Microsurgical Resection of a Middle Cerebellar Peduncle Cavernous Malformation: 3-Dimensional Operative Video.

Brainstem cavernous malformations are frequently surrounded by vital structures, which often makes surgical treatment a challenging task even to the most skilled surgeon. Accordingly, microsurgical excision is preferably offered to symptomatic patients and superficial lesions.1-3 We present the case of a 41-yr-old male presenting with progressive dizziness and diplopia. Neurological examination showed horizontal nystagmus, dysmetria, and unbalance. Preoperative magnetic resonance imaging (MRI) suggested a cavernous malformation in the right middle cerebellar peduncle. A telovelar approach was employed with the guidance of intraoperative neurophysiological monitoring. An exophytic lesion was identified in the right middle cerebellar peduncle and a clear cleavage plane was obtained allowing circumferential dissection around the capsule. The lesion was removed en bloc. Postoperative MRI confirmed a complete excision of the malformation. The patient presented an improvement in his initial symptoms, with no new neurological deficit. Cavernous malformations related with the fourth ventricle can be successfully resected through a telovelar approach in select cases, especially when exophytic, where the surgeon might take advantage of the path created by the lesion. Informed consent was obtained from the patient for the procedure and publication of this operative video. Anatomic images were a courtesy of the Rhoton Collection, American Association of Neurological Surgeons (AANS)/Neurosurgical Research and Education Foundation (NREF).