The Transantral Endoscopic Approach: A Portal for Masses of the Inferior Orbit-Improving Surgeons' Experience Through Virtual Endoscopy and Augmented Reality

In the past years, endoscopic techniques have raised an increasing interest to perform minimally invasive accesses to the orbit, resulting in excellent clinical outcomes with inferior morbidities and complication rates. Among endoscopic approaches, the transantral endoscopic approach allows us to create a portal to the orbital floor, representing the most straightforward access to lesions located in the inferior orbital space. However, if endoscopic surgery provides enhanced magnified vision of the anatomy in a bloodless field, then it has several impairments compared with classic open surgery, owing to restricted operative spaces. Virtual surgical planning and anatomical computer-generated models have proved to be of great importance to plan endoscopic surgical approaches, and their role can be widened with the integration of surgical navigation, virtual endoscopy simulation, and augmented reality (AR). This study focuses on the strict conjugation between the technologies that allow the virtualization of surgery in an entirely digital environment, which can be transferred to the patient using intraoperative navigation or to a printed model using AR for pre-surgical analysis. Therefore, the interaction between different software packages and platforms offers a highly predictive preview of the surgical scenario, contributing to increasing orientation, awareness, and effectiveness of maneuvers performed under endoscopic guidance, which can be checked at any time using surgical navigation. In this paper, the authors explore the transantral approach for the excision of masses of the inferior orbital compartment through modern technology. The authors apply this technique for masses located in the inferior orbit and share their clinical results, describing why technological innovation, and, in particular, computer planning, virtual endoscopy, navigation, and AR can contribute to empowering minimally invasive orbital surgery, at the same time offering a valuable and indispensable tool for pre-surgical analysis and training

A divergent cyclin/cyclin-dependent kinase complex controls the atypical replication of a malaria parasite during gametogony and transmission

Cell cycle transitions are generally triggered by variation in the activity of cyclin-dependent kinases (CDKs) bound to cyclins. Malaria-causing parasites have a life cycle with unique cell-division cycles, and a repertoire of divergent CDKs and cyclins of poorly understood function and interdependency. We show that Plasmodium berghei CDK-related kinase 5 (CRK5), is a critical regulator of atypical mitosis in the gametogony and is required for mosquito transmission. It phosphorylates canonical CDK motifs of components in the pre-replicative complex and is essential for DNA replication. During a replicative cycle, CRK5 stably interacts with a single Plasmodium-specific cyclin (SOC2), although we obtained no evidence of SOC2 cycling by transcription, translation or degradation. Our results provide evidence that during Plasmodium male gametogony, this divergent cyclin/CDK pair fills the functional space of other eukaryotic cell-cycle kinases controlling DNA replication

Ca2+ signals critical for egress and gametogenesis in malaria parasites depend on a multipass membrane protein that interacts with PKG.

Calcium signaling regulated by the cGMP-dependent protein kinase (PKG) controls key life cycle transitions in the malaria parasite. However, how calcium is mobilized from intracellular stores in the absence of canonical calcium channels in Plasmodium is unknown. Here, we identify a multipass membrane protein, ICM1, with homology to transporters and calcium channels that is tightly associated with PKG in both asexual blood stages and transmission stages. Phosphoproteomic analyses reveal multiple ICM1 phosphorylation events dependent on PKG activity. Stage-specific depletion of Plasmodium berghei ICM1 prevents gametogenesis due to a block in intracellular calcium mobilization, while conditional loss of Plasmodium falciparum ICM1 is detrimental for the parasite resulting in severely reduced calcium mobilization, defective egress, and lack of invasion. Our findings suggest that ICM1 is a key missing link in transducing PKG-dependent signals and provide previously unknown insights into atypical calcium homeostasis in malaria parasites essential for pathology and disease transmission

The hypoxia pathway and its key action in promoting chondrogenesis and inhibiting hypertrophy in a micromass cell culture model

Injured and diseased joint cartilage stands as the leading cause of disability, affecting approxi- mately 33% of the adult population. State-of-the-art treatments of destroyed joint cartilage are seriously limited. Tissue engineering, up to this point, has struggled to regenerate high-quality cartilage, encountering significant challenges such as dedifferentiation, hypertrophy, and degen- eration. BMP4, a potent inducer of chondrogenesis in mesenchymal cells, serves as a cornerstone in our approach. Additionally, we harness the power of hypoxia and its pivotal transcription factor, HIF1, responsible for cellular adaptation to hypoxic conditions, to foster chondrogenesis and curtail hypertrophic terminal differentiation and degeneration in vitro. Hypoxia stabilizes both HIF1 and HIF2, and current hypoxia mimetics, such as Roxadustat, act as HIF stabilizers. Within the framework of this thesis, we embarked on the exploration of a hypothesis positing that the sustained collaboration of BMP4 and HIF signaling serves as a driving force for robust chondrogenic differentiation in mesenchymal stem cells. This combined action simultaneously serves as a potent countermeasure against chondrocyte hypertrophy and degeneration. To repli- cate a physiologically relevant context, we adopted a micromass culture as our in vitro model, closely mimicking the mechanical microenvironment observed in vivo. Our investigation in- volved assessing the impact of Roxadustat and BMP4 on critical markers including Collagen I, II, X, and Sox 9, shedding light on their roles in stimulating chondrogenesis while effectively curbing hypertrophy in cartilage derived from embryonic limb mesenchymal stem cells. Our ongoing efforts in this project are geared towards addressing the formidable challenges presented by cartilage injuries, often characterized by irregular shapes. To facilitate ease of filling and minimally invasive procedures, our team has already devised an innovative approach. This entails the creation of biodegradable nanofibrous hollow microspheres through the self-assembly of a star-shaped poly(L-lactic acid), serving as a groundbreaking injectable carrier for chondro- cytes. These microspheres, once injected in an animal model, will enable the sustained release of BMP4 and Roxadustat, building upon the valuable insights gained from the experiments con- ducted in this thesis

Oxidative phosphorylation in bone cells

The role of energy metabolism in bone cells is an active field of investigation. Bone cells are metabolically very active and require high levels of energy in the form of adenosine triphosphate (ATP) to support their function. ATP is generated in the cytosol via glycolysis coupled with lactic acid fermentation and in the mitochondria via oxidative phosphorylation (OXPHOS). OXPHOS is the final convergent metabolic pathway for all oxidative steps of dietary nutrients catabolism. The formation of ATP is driven by an electrochemical gradient that forms across the mitochondrial inner membrane through to the activity of the electron transport chain (ETC) complexes and requires the presence of oxygen as the final electron acceptor. The current literature supports a model in which glycolysis is the main source of energy in undifferentiated mesenchymal progenitors and terminally differentiated osteoblasts, whereas OXPHOS appears relevant in an intermediate stage of differentiation of those cells. Conversely, osteoclasts progressively increase OXPHOS during differentiation until they become multinucleated and mitochondrial-rich terminal differentiated cells. Despite the abundance of mitochondria, mature osteoclasts are considered ATP-depleted, and the availability of ATP is a critical factor that regulates the low survival capacity of these cells, which rapidly undergo death by apoptosis. In addition to ATP, bioenergetic metabolism generates reactive oxygen species (ROS) and intermediate metabolites that regulate a variety of cellular functions, including epigenetics changes of genomic DNA and histones. This review will briefly discuss the role of OXPHOS and the cross-talks OXPHOS-glycolysis in the differentiation process of bone cells

Optimizing efficiency in the creation of patient-specific plates through field-driven generative design in maxillofacial surgery

Abstract Field driven design is a novel approach that allows to define through equations geometrical entities known as implicit bodies. This technology does not rely upon conventional geometry subunits, such as polygons or edges, rather it represents spatial shapes through mathematical functions within a geometrical field. The advantages in terms of computational speed and automation are conspicuous, and well acknowledged in engineering, especially for lattice structures. Moreover, field-driven design amplifies the possibilities for generative design, facilitating the creation of shapes generated by the software on the basis of user-defined constraints. Given such potential, this paper suggests the possibility to use the software nTopology, which is currently the only software for field-driven generative design, in the context of patient-specific implant creation for maxillofacial surgery. Clinical scenarios of applicability, including trauma and orthognathic surgery, are discussed, as well as the integration of this new technology with current workflows of virtual surgical planning. This paper represents the first application of field-driven design in maxillofacial surgery and, although its results are very preliminary as it is limited in considering only the distance field elaborated from specific points of reconstructed anatomy, it introduces the importance of this new technology for the future of personalized implant design in surgery

A divergent cyclin/cyclin-dependent kinase complex controls the atypical replication of a malaria parasite during gametogony and transmission

Cell cycle transitions are generally triggered by variation in the activity of cyclin-dependent kinases (CDKs) bound to cyclins. Malaria-causing parasites have a life cycle with unique cell-division cycles, and a repertoire of divergent CDKs and cyclins of poorly understood function and interdependency. We show that Plasmodium berghei CDK-related kinase 5 (CRK5), is a critical regulator of atypical mitosis in the gametogony and is required for mosquito transmission. It phosphorylates canonical CDK motifs of components in the pre-replicative complex and is essential for DNA replication. During a replicative cycle, CRK5 stably interacts with a single Plasmodium-specific cyclin (SOC2), although we obtained no evidence of SOC2 cycling by transcription, translation or degradation. Our results provide evidence that during Plasmodium male gametogony, this divergent cyclin/CDK pair fills the functional space of other eukaryotic cell-cycle kinases controlling DNA replication