Using Cardiohelp, Quadrox, and Nautilus Extracorporeal Membrane Oxygenators as Vascular Access for Hemodialysis, Continuous Renal Replacement Therapy, and Plasmapheresis: A Brief Technical Report.

The use of intermittent hemodialysis (iHD), and continuous renal replacement therapy (CRRT), along with extracorporeal membrane oxygenation (ECMO) in patients with acute kidney injury (AKI) and end-stage renal disease (ESRD) is very common. In this technical report, we describe the methods to perform these dialytic therapies safely and effectively using the ECMO circuit in lieu of a separate dialysis catheter. Specifically, we describe in detail how to connect these kidney replacement therapy modalities to a Quadrox, Nautilus, and Cardiohelp HLS (combined oxygenator and pump) oxygenator. The dialysis (iHD or CRRT) inlet is attached to the post-oxygenators Luer-Lock, whereas the return is attached to the pre-oxygenator Luer-Lock, both with a dual lumen pigtail. We also discuss the technical aspects of performing plasmapheresis in conjunction with ECMO and iHD or CRRT. Finally, we highlight the fact that the reported technique does not require modifying the ECMO cannulas/tubing which helps maximize safety.

Isotope systematics of subfossil, historical, and modern Nautilus macromphalus from New Caledonia.

Cephalopod carbonate geochemistry underpins studies ranging from Phanerozoic, global-scale change to outcrop-scale paleoecological reconstructions. Interpreting these data hinges on assumed similarity to model organisms, such as Nautilus, and generalization from other molluscan biomineralization processes. Aquarium rearing and capture of wild Nautilus suggest shell carbonate precipitates quickly (35 µm/day) in oxygen isotope equilibrium with seawater. Other components of Nautilus shell chemistry are less well-studied but have potential to serve as proxies for paleobiology and paleoceanography. To calibrate the geochemical response of cephalopod δ15Norg, δ13Corg, δ13Ccarb, δ18Ocarb, and δ44/40Cacarb to modern anthropogenic environmental change, we analyzed modern, historical, and subfossil Nautilus macromphalus from New Caledonia. Samples span initial human habitation, colonialization, and industrial pCO2 increase. This sampling strategy is advantageous because it avoids the shock response that can affect geochemical change in aquarium experiments. Given the range of living depths and more complex ecology of Nautilus, however, some anthropogenic signals, such as ocean acidification, may not have propagated to their living depths. Our data suggest some environmental changes are more easily preserved than others given variability in cephalopod average living depth. Calculation of the percent respired carbon incorporated into the shell using δ13Corg, δ13Ccarb, and Suess-effect corrected δ13CDIC suggests an increase in the last 130 years that may have been caused by increasing carbon dioxide concentration or decreasing oxygen concentration at the depths these individuals inhabited. This pattern is consistent with increasing atmospheric CO2 and/or eutrophication offshore of New Caledonia. We find that δ44/40Ca remains stable across the last 130 years. The subfossil shell from a cenote may exhibit early δ44/40Ca diagenesis. Questions remain about the proportion of dietary vs ambient seawater calcium incorporation into the Nautilus shell. Values of δ15N do not indicate trophic level change in the last 130 years, and the subfossil shell may show diagenetic alteration of δ15N toward lower values. Future work using historical collections of Sepia and Spirula may provide additional calibration of fossil cephalopod geochemistry.

Isotopic evidence concerning the habitat of Nautilus macromphalus in New Caledonia.

Modern nautilids (Nautilus and Allonautilus) have often been studied by paleontologists to better understand the anatomy and ecology of fossil relatives. Because direct observations of these animals are difficult, the analysis of light stable isotopes (C, O) preserved in their shells has been employed to reveal their habitat and life history. We aim to (1) reconstruct the habitat depth of Nautilus macromphalus and (2) decipher the fraction of metabolic carbon in its shell by analyzing oxygen and carbon isotopes (δ18O, δ13C) in the septa of two specimens in combination with analyses of water samples from the area. Additionally, we investigate whether morphological changes during ontogeny are reflected in the isotopic values of the shells. Results reveal that the patterns of change of δ18O and δ13C in the septa of N. macromphalus pre- and post-hatching are consistent with previous studies. Values of δ18Owater range from 0.7 to 1.4‰ (VSMOW), with a maximum value coincident with a salinity maximum at ~150 m. We use the temperature and δ18Owater profiles to calculate equilibrium values of δ18Oaragonite with depth. Comparing these values with the measured δ18O of the septa shows that the habitat depth of N. macromphalus is ~140 m pre-hatching and ~370 m post-hatching. Using δ13C of shell carbonate and published data on metabolic carbon, the fraction of metabolic carbon is reconstructed as ~21% and 14% pre- and post-hatching, respectively. The reconstructed depth pre-hatching is slightly shallower than in N. pompilius from the Philippines and Fiji, but the post-hatching depth is similar. However, it is important to emphasize that these estimates represent average over time and space because nautilus is a mobile animal. Lastly, the changes in morphological parameters and the changes in δ13C and δ18O during ontogeny do not coincide except at hatching and at the onset of maturity.

Intrasaccular neck-bridging: A technical note on Nautilus-assisted coiling of wide-necked cerebral aneurysms. Feasibility study, immediate and early angiographic results.

PURPOSE: Various adjunctive devices have been reported to be helpful during the endovascular coiling of complex, wide-necked cerebral aneurysms. This study aimed to describe the utilization of a recently introduced intrasaccular neck-bridging implant specifically designed to facilitate coil embolization. METHODS: We retrospectively reviewed eight consecutive patients who underwent treatment for intracranial aneurysms with the Nautilus intrasaccular bridging system between February 2022 to May 2022. We evaluated the angiographic appearances of treated aneurysms at the end of the procedure and early follow-up, the clinical status and complications. RESULTS: Eight patients with eight cerebral aneurysms (3 men and 5 women, mean age 52.8 years (range 39-66) were analyzed. Five of the treated aneurysms were managed in an acute case scenario. There were no technical difficulties while executing the technique. No other procedural adverse events were documented. Immediate complete occlusion of the aneurysm was seen in 6 patients, neck remnant in 1 and stable aneurysm reperfusion in one case. Early radiological follow-up was available in five patients, and the observed occlusion rates were - RR class I in all radiologically screened aneurysms. CONCLUSION: Nautilus-assisted coil embolization represents a rapid and safe solution for complex cerebral aneurysms. In our opinion this device symbolizes a significant step forward in treating intracranial aneurysms. We believe that the technique's actual value consists of the fact that the device is fully compatible with the modern low-profile microcatheter technology and does not involve the need for antiplatelet medications.

Functional Characterization, Antimicrobial Effects, and Potential Antibacterial Mechanisms of NpHM4, a Derived Peptide of Nautilus pompilius Hemocyanin.

Hemocyanins present in the hemolymph of invertebrates are multifunctional proteins that are responsible for oxygen transport and play crucial roles in the immune system. They have also been identified as a source of antimicrobial peptides during infection in mollusks. Hemocyanin has also been identified in the cephalopod ancestor Nautilus, but antimicrobial peptides derived from the hemocyanin of Nautilus pompilius have not been reported. Here, the bactericidal activity of six predicted peptides from N. pompilius hemocyanin and seven mutant peptides was analyzed. Among those peptides, a mutant peptide with 15 amino acids (1RVFAGFLRHGIKRSR15), NpHM4, showed relatively high antibacterial activity. NpHM4 was determined to have typical antimicrobial peptide characteristics, including a positive charge (+5.25) and a high hydrophobic residue ratio (40%), and it was predicted to form an alpha-helical structure. In addition, NpHM4 exhibited significant antibacterial activity against Gram-negative bacteria (MBC = 30 µM for Vibrio alginolyticus), with no cytotoxicity to mammalian cells even at a high concentration of 180 µM. Upon contact with V. alginolyticus cells, we confirmed that the bactericidal activity of NpHM4 was coupled with membrane permeabilization, which was further confirmed via ultrastructural images using a scanning electron microscope. Therefore, our study provides a rationalization for the development and optimization of antimicrobial peptide from the cephalopod ancestor Nautilus, paving the way for future novel AMP development with broad applications.

Nautilus-assisted coil embolization for a complex AcomA wide-necked aneurysm in the setting of acute subarachnoid hemorrhage.

Numerous devices and sophisticated strategies have been developed to further increase the number of aneurysms amenable to endovascular treatment.1-4 Despite the superfluity of available neurovascular armamentarium, wide-necked bifurcation aneurysms can still pose a significant technical challenge to the treating clinician.5-7 Neck bridging is a conceptually new approach, which provides increased occlusion rates with lower recurrence and complications rates.8-10 The Nautilus (EndoStream Medical) is an intrasaccular bridging device intended to assist in coil embolization of wide-necked cerebral aneurysms. This CE-marked device, available in various sizes, consists of flexible-layers, and is a nitinol-based, detachable implant. The device is delivered through a standard microcatheter with a minimal 0.0165" inner diameter and is fully radiopaque and completely resheathable.Owing to its unique 'tornado' like shape the device entirely reconstructs the aneurysmal neck, which facilitates the following coil embolization. In this video 1, we demonstrate the use of Nautilus - assisted coil embolization for a complex anterior communicating artery (AcomA) wide-necked aneurysm in the setting of acute subarachnoid hemorrhage. neurintsurg;14/3/310/V1F1V1Video 1.

Genomic insights into the adaptation and evolution of the nautilus, an ancient but evolving "living fossil".

The nautilus, commonly known as a "living fossil," is endangered and may be at risk of extinction. The lack of genomic information hinders a thorough understanding of its biology and evolution, which can shed light on the conservation of this endangered species. Here, we report the first high-quality chromosome-level genome assembly of Nautilus pompilius. The assembled genome size comprised 785.15 Mb. Comparative genomic analyses indicated that transposable elements (TEs) and large-scale genome reorganizations may have driven lineage-specific evolution in the cephalopods. Remarkably, evolving conserved genes and recent TE insertion activities were identified in N. pompilius, and we speculate that these findings reflect the strong adaptability and long-term survival of the nautilus. We also identified gene families that are potentially responsible for specific adaptation and evolution events. Our study provides unprecedented insights into the specialized biology and evolution of N. pompilius, and the results serve as an important resource for future conservation genomics of the nautilus and closely related species.

Hydrophilic Shell Matrix Proteins of Nautilus pompilius and the Identification of a Core Set of Conchiferan Domains.

Despite being a member of the shelled mollusks (Conchiferans), most members of extant cephalopods have lost their external biomineralized shells, except for the basally diverging Nautilids. Here, we report the result of our study to identify major Shell Matrix Proteins and their domains in the Nautilid Nautilus pompilius, in order to gain a general insight into the evolution of Conchiferan Shell Matrix Proteins. In order to do so, we performed a multiomics study on the shell of N. pompilius, by conducting transcriptomics of its mantle tissue and proteomics of its shell matrix. Analyses of obtained data identified 61 distinct shell-specific sequences. Of the successfully annotated 27 sequences, protein domains were predicted in 19. Comparative analysis of Nautilus sequences with four Conchiferans for which Shell Matrix Protein data were available (the pacific oyster, the pearl oyster, the limpet and the Euhadra snail) revealed that three proteins and six protein domains were conserved in all Conchiferans. Interestingly, when the terrestrial Euhadra snail was excluded, another five proteins and six protein domains were found to be shared among the four marine Conchiferans. Phylogenetic analyses indicated that most of these proteins and domains were probably present in the ancestral Conchiferan, but employed in shell formation later and independently in most clades. Even though further studies utilizing deeper sequencing techniques to obtain genome and full-length sequences, and functional analyses, must be carried out in the future, our results here provide important pieces of information for the elucidation of the evolution of Conchiferan shells at the molecular level.

An Ingenious Microstructure Arrangement in Deep-Sea Nautilus Shell against the Harsh Environment.

Mollusk shells generally consist of several macro-layers with different microstructures. To explore the specific role that different macro-layers play in the overall mechanical properties of shells, the microstructures, hardness distribution, and three-point bending behavior in the deep-sea Nautilus shell were investigated. It is found that the shell presents a hierarchical structure comprising three layers in thickness, that is, the outer, middle, and inner layers, which exhibit homogeneous, prismatic, and nacreous structures, respectively. Among them, the homogeneous structure in the outer layer is harder, which is beneficial for the shell to enhance resistance to wear and perforation. Furthermore, both the bending strength and fracture energy for group Up (loading from outer to inner surfaces) are far higher than those for group Down (loading from inner to outer surfaces), indicating that the inner nacreous layer is not only stronger but also tougher. Cracks tend to deflect at the interfaces in nacreous structure, and nacreous structure is thereby more resistant to breakage. Hence, the nacreous structure in the inner layer could protect the shell from breaking catastrophically in the deep sea with high pressure. In brief, the combination of a harder outside layer and a tougher inside layer provides an effective protective structure for the deep-sea shell, and the excellent environment adaptability of Nautilus shell can thus be interpreted in terms of its ingenious microstructure arrangement.

Significance of the suture line in cephalopod taxonomy revealed by 3D morphometrics in the modern nautilids Nautilus and Allonautilus.

Assessing the taxonomic importance of the suture line in shelled cephalopods is a key to better understanding the diversity of this group in Earth history. Because fossils are subject to taphonomic artifacts, an in-depth knowledge of well-preserved modern organisms is needed as an important reference. Here, we examine the suture line morphology of all known species of the modern cephalopods Nautilus and Allonautilus. We applied computed tomography and geometric morphometrics to quantify the suture line morphology as well as the conch geometry and septal spacing. Results reveal that the suture line and conch geometry are useful in distinguishing species, while septal spacing is less useful. We also constructed cluster trees to illustrate the similarity among species. The tree based on conch geometry in middle ontogeny is nearly congruent with those previously reconstructed based on molecular data. In addition, different geographical populations of the same species of Nautilus separate out in this tree. This suggests that genetically distinct (i.e., geographically isolated) populations of Nautilus can also be distinguished using conch geometry. Our results are applicable to closely related fossil cephalopods (nautilids), but may not apply to more distantly related forms (ammonoids).

Nautilus-Assisted Coiling of an Unruptured Wide-Necked Aneurysm of the Posterior Communicating Artery.

A variety of recently introduced devices have allowed more complex aneurysms to be rendered for endovascular embolization. Tiny and sophisticated implants are nowadays designed to provide further either temporary or permanent remodeling of the wide-necked aneurysms and improve coil occlusion rates.1-4 Such improvements in the technical armamentarium include the Woven EndoBridge (Sequent Medical, California, USA), the Medina Embolic Device (Medtronic, Irvine, California, USA), The Contour Neurovascular System (Cerus Endovascular, Fremont, California, USA), and pCONUS 2 HPC (Phenox, GmbH, Bohum, Germany).5-7 Intrasaccular neck bridging is a conceptually new technique descending from the theoretical combination of intrasaccular flow diversion and temporary-stent assisted coiling.8 The Nautilus (EndoStream Medical, Tel Aviv, Israel) is an intrasaccular bridging device that offers complete neck reconstruction in coil embolization of wide-neck cerebral aneurysms. It has been granted a CE mark by the European Union. The detachable intrasaccular implant comprises flexible and "tornado-like"-shaped Nitinol-based layers. The device is compatible with a standard microcatheter with minimal 0.0165″ inner diameter and is fully radiopaque and fully resheathable. The device's intrasaccular nature and the fact that it does not harbor any intraluminal satellite parts suggest that the implant can be safely used in both unruptured and ruptured case scenarios without the need for dual antiplatelet therapy. This is what we consider a great advantage of the proposed technique over the alternative options of intrasaccular and intraluminal flow diversion. This technical video (Video 1) demonstrates the successful obliteration of a complex posterior communicating artery aneurysm with Nautilus-assisted endovascular coiling. To our knowledge, this is the first technical video demonstrating an in-vivo and step-by-step implementation of this novel device.

The genome of Nautilus pompilius illuminates eye evolution and biomineralization.

Nautilus is the sole surviving externally shelled cephalopod from the Palaeozoic. It is unique within cephalopod genealogy and critical to understanding the evolutionary novelties of cephalopods. Here, we present a complete Nautilus pompilius genome as a fundamental genomic reference on cephalopod innovations, such as the pinhole eye and biomineralization. Nautilus shows a compact, minimalist genome with few encoding genes and slow evolutionary rates in both non-coding and coding regions among known cephalopods. Importantly, multiple genomic innovations including gene losses, independent contraction and expansion of specific gene families and their associated regulatory networks likely moulded the evolution of the nautilus pinhole eye. The conserved molluscan biomineralization toolkit and lineage-specific repetitive low-complexity domains are essential to the construction of the nautilus shell. The nautilus genome constitutes a valuable resource for reconstructing the evolutionary scenarios and genomic innovations that shape the extant cephalopods.

A Nautilus kidney.

We report a 71-year-old woman who presented with unilateral flank pain and sepsis. A computed tomographic (CT) scan demonstrated left-sided hydronephrosis. Subsequent percutaneous nephrotomy drainage showed pus-like material, confirming the diagnosis of pyonephrosis. The ureteral stricture was caused by previous radiation injury for cervical cancer in this ESRD patient who was on chronic dialysis for years. In our case, the grade IVB hydronephrosis is a result of an extremely atrophic kidney, pyonephrosis, and ureteral stricture. The CT section of pyonephrosis in an extremely atrophic kidney resembles a sagittal section of a Nautilus shell, as the shell corresponds to the diffusely thinned renal cortex.

Chirostyloidean squat lobsters (Crustacea: Decapoda: Anomura) from the Galapagos Islands.

Seven species of chirostyloidean squat lobsters are reported from the Galapagos Rift zone and Galapagos platform: Eumunida subsolanus n. sp. (Eumunididae), Heteroptychus galapagos n. sp., H. nautilus n. sp. (Chirostylidae), Uroptychus bellus Faxon, 1893, U. compressus n. sp., U. occidentalis Faxon, 1893 (Chirostylidae), and Sternostylus defensus (Benedict, 1902) (Sternostylidae). All new species are described and illustrated, and the two species previously known from the Galapagos Islands, Uroptychus bellus and U. occidentalis, are re-illustrated from respective lectotypes, herein designated, since both original descriptions were only brief. Both the species of Heteroptychus and Eumunida subsolanus are the first representatives of their respective genera in the eastern Pacific and the latter is also the first record for the family Eumunididae in the region.

The utility of micro-computed tomography for the non-destructive study of eye microstructure in snails.

Molluscan eyes exhibit an enormous range of morphological variation, ranging from tiny pigment-cup eyes in limpets, compound eyes in ark clams and pinhole eyes in Nautilus, through to concave mirror eyes in scallops and the large camera-type eyes of the more derived cephalopods. Here we assess the potential of non-destructive micro-computed tomography (µ-CT) for investigating the anatomy of molluscan eyes in three species of the family Solariellidae, a group of small, deep-sea gastropods. We compare our results directly with those from traditional histological methods applied to the same specimens, and show not only that eye microstructure can be visualised in sufficient detail for meaningful comparison even in very small animals, but also that µ-CT can provide additional insight into gross neuroanatomy without damaging rare and precious specimens. Data from µ-CT scans also show that neurological innervation of eyes is reduced in dark-adapted snails when compared with the innervation of cephalic tentacles, which are involved in mechanoreception and possibly chemoreception. Molecular tests also show that the use of µ-CT and phosphotungstic acid stain do not prevent successful downstream DNA extraction, PCR amplification or sequencing. The use of µ-CT methods is therefore highly recommended for the investigation of difficult-to-collect or unique specimens.

Deep-water cirripedes colonizing dead shells of the cephalopod Nautilus macromphalus from New Caledonian waters.

Fossil cephalopods are frequently encrusted by epibionts; however, determining whether encrustation occurred prior to or post-mortem to the host, and whether the final environment of deposition corresponds to the habitat of encrustation is complex. The present paper describes cirripede epibionts, their calcareous bases and their attachment scars on 6 post-mortem shells of Nautilus macromphalus, collected from deep water off New Caledonia. The cirripedes have left both cemented calcareous bases of Hexelasma and scars associated with bioerosion and discoloration produced by verrucomorph barnacles. Live cirripedes included a Metaverruca recta, with articulated opercular plates and organic tissue (on a shell that had been exposed on the sea floor for at least 150 years), and specimens of Hexelasma velutinum, one of which was partly attached to an internal surface of a shell. The disposition of verrucomorphs indicates that most Nautilus shells were colonized post-mortem rather than during a floating stage. However, as cirripedes are known to have colonized living Nautilus, some Hexelasma, preserved only as calcareous eroded bases, may represent specimens that settled on a living Nautilus. The degree of bioerosion and discoloration induced by verrucomorph barnacles varies according to the surface preservation of Nautilus shells, with deeper and discolored traces preserved on old and degraded shells. Traces made by verrucomorphs described here are ellipsoidal and a new ichnotaxon, Anellusichnus ellipticus, is proposed to accommodate them. Importantly, verrucomorphs and other cirripede taxa with membranous bases that were attached to pristine shells may not leave any substantial scars, and, thus, will be difficult to detect in the fossil record.

Antibiotic Treatment of Mucodegeneration and Positive Buoyancy in a Chambered Nautilus Nautilus pompilius.

The correct diagnosis and treatment of disease in chambered nautiluses Nautilus pompilius are difficult. The basic morphology and natural behaviors of the species tend to mask the initial onset of a disease or infection, and by the time it is observable, mortality usually occurs. A single specimen of chambered nautilus at the Museum of Nature South Tyrol, Italy, exhibited symptoms of an infection, including mucus production, abnormal buoyancy, irregular hood appearance, and inconsistent tentacle movement. Soon after, tetracycline hydrochloride was administered in bath form at 25 mg/L in seawater daily for 30 min over six consecutive days. The specimen regained normal buoyancy after the fifth day. After the 6-d treatment, the specimen regained all normal behaviors and appearance within 2 weeks. More than 1 year after treatment, the specimen was exhibiting normal behaviors with no adverse reactions. When administered soon after symptoms of an infection were observed, tetracycline was effective at halting the progression of symptoms and led to the full recovery of the chambered nautilus.

Genomic signatures of evolution in Nautilus-An endangered living fossil.

Living fossils are survivors of previously more diverse lineages that originated millions of years ago and persisted with little morphological change. Therefore, living fossils are model organisms to study both long-term and ongoing adaptation and speciation processes. However, many aspects of living fossil evolution and their persistence in the modern world remain unclear. Here, we investigate three major aspects of the evolutionary history of living fossils: cryptic speciation, population genetics and effective population sizes, using members of the genera Nautilus and Allonautilus as classic examples of true living fossils. For this, we analysed genomewide ddRAD-Seq data for all six currently recognized nautiloid species throughout their distribution range. Our analyses identified three major allopatric Nautilus clades: a South Pacific clade, subdivided into three subclades with no signs of admixture between them; a Coral Sea clade, consisting of two genetically distinct populations with significant admixture; and a widespread Indo-Pacific clade, devoid of significant genetic substructure. Within these major clades, we detected five Nautilus groups, which likely correspond to five distinct species. With the exception of Nautilus macromphalus, all previously described species are at odds with genomewide data, testifying to the prevalence of cryptic species among living fossils. Detailed FST analyses further revealed significant genome-wide and locus-specific signatures of selection between species and differentiated populations, which is demonstrated here for the first time in a living fossil. Finally, approximate Bayesian computation (ABC) simulations suggest large effective population sizes, which may explain the low levels of population differentiation commonly observed in living fossils.

Spiral Form of the Human Cochlea Results from Spatial Constraints.

The human inner ear has an intricate spiral shape often compared to shells of mollusks, particularly to the nautilus shell. It has inspired many functional hearing theories. The reasons for this complex geometry remain unresolved. We digitized 138 human cochleae at microscopic resolution and observed an astonishing interindividual variability in the shape. A 3D analytical cochlear model was developed that fits the analyzed data with high precision. The cochlear geometry neither matched a proposed function, namely sound focusing similar to a whispering gallery, nor did it have the form of a nautilus. Instead, the innate cochlear blueprint and its actual ontogenetic variants were determined by spatial constraints and resulted from an efficient packing of the cochlear duct within the petrous bone. The analytical model predicts well the individual 3D cochlear geometry from few clinical measures and represents a clinical tool for an individualized approach to neurosensory restoration with cochlear implants.