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1.
Sol Phys ; 299(8): 120, 2024.
Article in English | MEDLINE | ID: mdl-39220341

ABSTRACT

The Solar eruptioN Integral Field Spectrograph (SNIFS) is a solar-gazing spectrograph scheduled to fly in the summer of 2025 on a NASA sounding rocket. Its goal is to view the solar chromosphere and transition region at a high cadence (1 s) both spatially ( 0.5 ″ ) and spectrally (33 mÅ) viewing wavelengths around Lyman alpha (1216 Å), Si iii (1206 Å), and O v (1218 Å) to observe spicules, nanoflares, and possibly a solar flare. This time cadence will provide yet-unobserved detail about fast-changing features of the Sun. The instrument is comprised of a Gregorian-style reflecting telescope combined with a spectrograph via a specialized mirrorlet array that focuses the light from each spatial location in the image so that it may be spectrally dispersed without overlap from neighboring locations. This paper discusses the driving science, detailed instrument and subsystem design, and preintegration testing of the SNIFS instrument.

2.
Parasitology ; 150(11): 1022-1030, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37705292

ABSTRACT

Nematode spicules play a vital role in the reproductive activity of species that possess them. Our primary objective was to compare the lengths of spicules of the laboratory mouse (Mus musculus) ­ maintained isolate H. bakeri ­ with those of H. polygyrus from naturally infected wood mice (Apodemus sylvaticus). On a more limited scale, we also included H. glareoli from bank voles (Myodes glareolus), a species reputed to possess longer spicules than either of the 2 former species. In total, we measured 1264 spicules (H. bakeri, n = 614; H. polygyrus n = 582; and H. glareoli, n = 68). There was a highly significant difference between the spicule lengths of the Nottingham-maintained H. bakeri (mean = 0.518 mm) and H. polygyrus (0.598 mm) from 11 different localities across the British Isles. A comparison of the spicules of H. bakeri maintained in 4 different laboratories in 3 continents revealed a range in the mean values from 0.518 to 0.540 mm, while those of worms from Australian wild house mice were shorter (0.480 mm). Mean values for H. polygyrus from wood mice from the British Isles ranged from 0.564 to 0.635 mm, although isolates of this species from Norway had longer spicules (0.670 mm). In agreement with the literature, the spicules of H. glareoli were considerably longer (1.098 mm). Since spicules play a vital role in the reproduction of nematode species that possess them, the difference in spicule lengths between H. bakeri and H. polygyrus adds to the growing evidence that these 2 are quite distinct species and likely reproductively isolated.


Subject(s)
Nematospiroides dubius , Animals , Mice , Australia , Murinae , Norway
3.
Exp Dermatol ; 31(9): 1402-1410, 2022 09.
Article in English | MEDLINE | ID: mdl-35587729

ABSTRACT

Chronic itch is a socioeconomic burden with limited management options. Non-histaminergic itch, involved in problematic pathological itch conditions, is transmitted by a subgroup of polymodal C-fibres. Cowhage is traditionally used for studying experimentally induced non-histaminergic itch in humans but encounters some limitations. The present study, therefore, aims to design a new human, experimental model of non-histaminergic itch based on the application of bovine adrenal medulla (BAM)8-22, an endogenous peptide that activates the MrgprX1 receptor. Twenty-two healthy subjects were recruited. Different concentrations (0.5, 1 and 2 mg/ml) of BAM8-22 solution and vehicle, applied by a single skin prick test (SPT), were tested in the first session. In the second session, the BAM8-22 solution (1 mg/ml) was applied by different number of SPTs (1, 5 and 25) and by heat-inactivated cowhage spicules coated with BAM8-22. Provoked itch and pain intensities were monitored for 9 min, followed by the measurement of superficial blood perfusion (SBP) and mechanical and thermal sensitivities. BAM8-22 induced itch at the concentration of 1, 2 mg/ml (p < 0.05) and with the significantly highest intensity when applied through BAM8-22 spicules (p < 0.001). No concomitant pain sensation or increased SBP was observed. SBP increased only in the 25 SPTs area probably due to microtrauma from the multiple skin penetrations. Mechanical and thermal sensitivities were not affected by any of the applications. BAM8-22 applied through heat-inactivated spicules was the most efficient method to induce itch (without pain or changes in SBP and mechanical and thermal sensitivities) suggesting BAM8-22 as a novel non-histaminergic, human, experimental itch model.


Subject(s)
Adrenal Medulla , Pruritus , Animals , Cattle , Humans , Pain/chemically induced , Peptide Fragments/adverse effects , Pruritus/chemically induced
4.
J Cutan Pathol ; 48(9): 1124-1132, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33675561

ABSTRACT

BACKGROUNDS: Follicular mycosis fungoides (FMFs) is a distinct form of T-cell lymphoma whose course is considered aggressive. METHODS: A retrospective study with long-term follow-up of 20 patients diagnosed with spiky/keratosis-pilaris-like FMF between 2008 and 2017 was conducted. RESULTS: Twelve males and eight females were identified, with a mean age at first diagnosis of 59 years (range 42-86). Hyperkeratotic follicular papules were the sole clinical finding in 16 of 20 patients. A diagnostic delay between first symptom development and initial diagnosis was frequent (mean 42 months). The head/neck region was concurrently affected only in two patients. Disease stage at diagnosis was IA in two patients (10%) and IB in 18 (90%). Five patients had almost complete lesion regression, whilst there was only a slight improvement, without regression in 14. Two patients developed infiltrated papules, comedones, and small cysts during follow-up. Only one patient progressed to tumor stage (IIB) five years after the first diagnosis. The mean follow-up was seven years (range: 12-180 months). None of them died of cutaneous lymphoma. CONCLUSIONS: FMF presenting with only spiky/keratosis-pilaris-like lesions have an excellent prognosis at medium-term follow-up. Early recognition of patients with this peculiar FMF presentation might lead to identifying prognostic factors.


Subject(s)
Abnormalities, Multiple/diagnosis , Darier Disease/diagnosis , Eyebrows/abnormalities , Mycosis Fungoides/diagnosis , Skin Neoplasms/pathology , Abnormalities, Multiple/pathology , Adult , Aged , Aged, 80 and over , Darier Disease/pathology , Delayed Diagnosis , Disease Progression , Eyebrows/pathology , Female , Follow-Up Studies , Humans , Lymphoma, T-Cell/pathology , Male , Middle Aged , Mycosis Fungoides/pathology , Neoplasm Staging/methods , Prognosis , Retrospective Studies
5.
Mar Drugs ; 19(12)2021 Nov 26.
Article in English | MEDLINE | ID: mdl-34940669

ABSTRACT

Toxic crabs of the family Xanthidae contain saxitoxins (STXs) and/or tetrodotoxin (TTX), but the toxin ratio differs depending on their habitat. In the present study, to clarify within reef variations in the toxin profile of xanthid crabs, we collected specimens of the toxic xanthid crab Zosimus aeneus and their sampling location within a single reef (Yoshihara reef) on Ishigaki Island, Okinawa Prefecture, Japan, in 2018 and 2019. The STXs/TTX content within the appendages and viscera or stomach contents of each specimen was determined by instrumental analyses. Our findings revealed the existence of three zones in Yoshihara reef; one in which many individuals accumulate extremely high concentrations of STXs (northwestern part of the reef; NW zone), another in which individuals generally have small amounts of TTX but little STXs (central part of the reef; CTR zone), and a third in which individuals generally exhibit intermediate characteristics (southeastern part of the reef; SE zone). Furthermore, light microscopic observations of the stomach contents of crab specimens collected from the NW and CTR zones revealed that ascidian spicules of the genus Lissoclinum were dominant in the NW zone, whereas those of the genus Trididemnum were dominant in the CTR zone. Although the toxicity of these ascidians is unknown, Lissoclinum ascidians are considered good candidate source organisms of STXs harbored by toxic xanthid crabs.


Subject(s)
Brachyura , Marine Toxins/chemistry , Animals , Aquatic Organisms , Demography , Japan , Pacific Ocean
6.
J Helminthol ; 95: e45, 2021 Aug 20.
Article in English | MEDLINE | ID: mdl-34412717

ABSTRACT

The spicules of male parasitic nematodes are key morphological features, which vary between species in shape and length and are used often for species identification. However, little is known about spicules and particularly if/how their length varies during growth. We first assessed the degree of variation in spicule length of male Heligmosomoides bakeri 21 days post infection (PI), and then in two follow-up experiments measured spicule lengths at half daily/daily intervals between days 6 and 14 PI. Mean spicule length in 21-day worms was 0.518 mm with a range of 94 µm, and variation between the two spicules of individual worms from 2 to 32 µm. Spicules were first detectable on day 6-6.5, after which their lengths increased until day 7 PI (mean = 0.61 and 0.59). This was followed by significant contraction, initially relatively quickly over the following 48 h and then more slowly over a longer period, stabilizing by days 10-14, with only minor further reduction in length. We conclude that the length of spicules varies significantly over the first few days after they have formed, and, consequently, the age of worms is an important factor for consideration when spicule lengths are measured for experimental/diagnostic or taxonomical purposes.


Subject(s)
Nematoda , Trichostrongyloidea , Animals , Male
7.
J Helminthol ; 95: e69, 2021 Nov 22.
Article in English | MEDLINE | ID: mdl-34802477

ABSTRACT

Nematode spicules vary in shape and size even between closely related species and, therefore, constitute key characters in nematode taxonomy for distinguishing between species. Spicules are seldom measured on fresh specimens, but rather at some time after extraction from culled hosts and after a period of preservation of the worms in chemical fixatives or by freezing. We carried out two experiments to assess the effects of freezing in Hanks' balanced salt solution, 70% or 80% ethanol and 10% formalin (both of the latter at room temperature and after storage at -80°C) on spicule length of Heligmosomoides bakeri at two time intervals after extraction from mice (Experiment 1, one and four weeks; Experiment 2, one and four months). In Experiment 1, no significant differences were detected, although there was some variation between treatments and over time. In Experiment 2, spicule length varied significantly between treatments and over time, the greatest shrinkage being in 80% ethanol and the least in 10% formalin. However, overall variation in spicule length was very limited, accounting for no more than 5.03% change in length over time and 4.95% between treatments at any of the periods of assessment. Therefore, while whole nematodes can shrivel and shrink in preservatives, making many measurements unreliable, our data indicated that spicule lengths are very little changed by preservation techniques over time, and so spicule length remains as a reliable taxonomic character.


Subject(s)
Heligmosomatoidea , Nematoda , Trichostrongyloidea , Animals , Mice
8.
Biotechnol Bioeng ; 117(6): 1789-1804, 2020 06.
Article in English | MEDLINE | ID: mdl-32068251

ABSTRACT

During evolution, sponges (Porifera) have honed the genetic toolbox and biosynthetic mechanisms for the fabrication of siliceous skeletal components (spicules). Spicules carry a protein scaffold embedded within biogenic silica (biosilica) and feature an amazing range of optical, structural, and mechanical properties. Thus, it is tempting to explore the low-energy synthetic pathways of spiculogenesis for the fabrication of innovative hybrid materials. In this synthetic biology approach, the uptake of multifunctional nonbiogenic nanoparticles (fluorescent, superparamagnetic) by spicule-forming cells of bioreactor-cultivated sponge primmorphs provides access to spiculogenesis. The ingested nanoparticles were detected within intracellular vesicles resembling silicasomes (silica-rich cellular compartments) and as cytosolic clusters where they lent primmorphs fluorescent/magnetic properties. During spiculogenesis, the nanoparticles initially formed an incomplete layer around juvenile, intracellular spicules. In the mature, extracellular spicules the nanoparticles were densely arranged as a surface layer that rendered the resulting composite fluorescent and magnetic. By branching off the conventional route of solid-state materials synthesis under harsh conditions, a new pathway has been opened to a versatile platform that allows adding functionalities to growing spicules as templates in living cells, using nonbiogenic nanoscale building blocks with multiple functionalities. The magnet-assisted alignment renders this composite with its fluorescent/magnetic properties potentially suitable for application in biooptoelectronics and microelectronics (e.g., microscale on-chip waveguides for applications of optical detection and sensing).


Subject(s)
Fluorescent Dyes/chemistry , Magnets/chemistry , Porifera/chemistry , Porifera/growth & development , Silicon Dioxide/chemistry , Animals , Bioreactors , Fluorescent Dyes/metabolism , Magnetic Iron Oxide Nanoparticles/chemistry , Porifera/metabolism , Silicon Dioxide/metabolism , Synthetic Biology/methods
9.
Mol Phylogenet Evol ; 131: 245-253, 2019 02.
Article in English | MEDLINE | ID: mdl-30502904

ABSTRACT

The skeletons of sponges (Phylum Porifera) are comprised of collagen, often embedded with small siliceous structures (spicules) arranged in various forms to provide strength and flexibility. The main proteins responsible for the formation of the spicules in demosponges are the silicateins, which are related to the cathepsins L of other animals. While the silicatein active site, necessary for the formation of biosilica crystals, is characterized by the amino acids SHN, different variants of the silicatein genes have been found, some that retain SHN at the active site and some that don't. As part of an effort to further understand skeleton formation in marine sponges of the order Haplosclerida, a search for all silicatein variants were made in Irish species representing the main clades of this large sponge group. For this task, transcriptomes were sequenced and de novo assembled from Haliclona oculata, H. simulans and H. indistincta. Silicatein genes were identified from these and all available genomes and transcriptomes from Porifera. These were analysed along with all complete silicateins from GenBank. Silicateins were only found in species belonging to the class Demospongiae but excluding Keratosa and Verongimorpha and there was significant duplication and diversity of these genes. Silicateins showing SHN at the active site were polyphyletic. Indeed silicatein sequences were divided into six major clades (CHNI, CHNII, CHNIII, SHNI, SHNII and C/SQN). In those clades where haplosclerids were well represented the silicatein phylogeny reflected previous ribosomal and mitochondrial topologies. The most basal silicatein clade (CHNI) contained sequences only from marine haplosclerids and freshwater sponges while one silicatein from H. indistincta was more related to cathepsins L (outgroup) than to the overall silicatein clade indicating the presence of an old silicatein or an intermediary form. This data could suggest that marine haplosclerids were one of the first groups of extant demosponges to acquire silicatein genes. Furthermore, we suggest that the paucity of spicule types in this group may be due to their single copy of SHNI variants, and the lack of a silintaphin gene.


Subject(s)
Bone and Bones/anatomy & histology , Evolution, Molecular , Porifera/genetics , Animals , Base Sequence , Phylogeny , Transcriptome/genetics
10.
Dev Growth Differ ; 61(9): 485-500, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31820450

ABSTRACT

We previously revealed that the mechanism of demosponge skeleton construction is self-organization by multiple rounds of sequential mechanical reactions of player cells. In these reactions, "transport cells" dynamically carry fine skeletal elements (spicules) on epithelia surrounding the inner body space of sponges (basal epithelium (basopinacoderm) and the endodermal epithelium (ENCM)). Once spicules pierce ENCM and apical pinacoderm, subsequently they are cemented to the substratum under the sponge body, or connected to other skeleton-constructing spicules. Thus, the "pierce" step is the key to holding up spicules in the temporary periphery of growing sponges' bodies. Since sponges can regress as well as grow, here we asked how skeleton construction occurs during local regression of the body. We found that prior to local basopinacoderm retraction (and thus body regression), the body became thinner. Some spicules that were originally carried outward stagnated for a while, and were then carried inwards either on ENCM or basopinacoderm. Spicules that were carried inwards on ENCM pierced epithelia after a short transport, and thus became held up at relatively inward positions compared to spicules carried on outwardly extending basopinacoderm. The switch of epithelia on which transport cells migrate efficiently occurred in thinner body spaces where basopinacoderm and ENCM became close to each other. Thus, the mechanisms underlying this phenomenon are rather mechanical: the combination of sequential reactions of skeleton construction and the narrowed body space upon local retraction of basopinacoderm cause spicules to be held up at more-inward positions, which might strengthen the basopinacoderm's attachment to substratum.


Subject(s)
Epithelium/metabolism , Porifera , Skin/metabolism , Animals
11.
J Cutan Pathol ; 46(11): 844-851, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31161673

ABSTRACT

Herein, we describe a patient with immunoglobulin G (IgG)-lambda smoldering multiple myeloma with translocation t(4:14) who developed widespread ulcerative horny-like spicules, heralding rapid progression to overt myeloma requiring aggressive chemotherapy and autologous stem cell transplantation. The serum abnormal immunoglobulin in the blood was cryoglobulin, which typically precipitates in the tissues at low temperatures causing inflammation and tissue damage. Histopathological changes, observed in lesions at different evolutionary stages, evidenced columns of horny-like eosinophilic homogeneous material, immunoreactive for IgG lambda, protruding from the dilated and/or distorted follicular openings or acrosyringia and small vessel thrombotic vasculopathy and vasculitis in concert with an inflammatory neutrophilic and lymphocytic reaction. Biochemical investigations on material from a spicule and ulcero-necrotic lesion revealed cryoprecipitates containing IgG-lambda with electrophoretic characteristics identical to those of the serum dysprotein. Our findings suggest that the formation of spicules and development of ulcerative lesions are a part of the same clinical spectrum where the cold-dependent precipitation of the immunogenic dysprotein, both in the skin vessels and hair follicle infundibula, play a major pathogenetic role. Whether this highly characteristic paraneoplastic dermatosis can identify patients with high-risk cytogenetic abnormalities and be incorporated into prognostic models, applicable early on in the course of myeloma, warrants further investigation.


Subject(s)
Chromosomes, Human, Pair 14/genetics , Chromosomes, Human, Pair 4/genetics , Multiple Myeloma , Skin Neoplasms , Smoldering Multiple Myeloma , Translocation, Genetic , Autografts , Hair Follicle/metabolism , Hair Follicle/pathology , Hematopoietic Stem Cell Transplantation , Humans , Male , Middle Aged , Multiple Myeloma/genetics , Multiple Myeloma/metabolism , Multiple Myeloma/pathology , Multiple Myeloma/therapy , Skin Neoplasms/genetics , Skin Neoplasms/metabolism , Skin Neoplasms/pathology , Skin Neoplasms/therapy , Smoldering Multiple Myeloma/genetics , Smoldering Multiple Myeloma/metabolism , Smoldering Multiple Myeloma/pathology , Smoldering Multiple Myeloma/therapy , Transplantation, Autologous
12.
Mol Pharm ; 14(9): 3188-3200, 2017 09 05.
Article in English | MEDLINE | ID: mdl-28763230

ABSTRACT

We report the development of sponge Haliclona sp. spicules, referred to as SHS, and its topical application in skin delivery of hydrophilic biomacromolecules, a series of fluorescein isothiocyanate-dextrans (FDs). SHS are silicious oxeas which are sharp-edged and rod-shaped (∼120 µm in length and ∼7 µm in diameter). SHS can physically disrupt skin in a dose-dependent manner and retain within the skin over at least 72 h, which allows sustained skin penetration of hydrophilic biomacromolecules. The magnitude of enhancement of FD delivery into skin induced by SHS treatment was dependent on its molecular weight. Specifically, SHS topical application enhanced FD-10 (MW: 10 kDa) penetration into porcine skin in vitro by 33.09 ± 7.16-fold compared to control group (p < 0.01). SHS dramatically increased the accumulation of FD-10 into and across the dermis by 62.32 ± 13.48-fold compared to the control group (p < 0.01). In vivo experiments performed using BALB/c mice also confirmed the effectiveness of SHS topical application; the skin absorption of FD-10 with SHS topical application was 72.14 ± 48.75-fold (p < 0.05) and 15.39 ± 9.91-fold (p < 0.05) higher than those from the PBS and Dermaroller microneedling, respectively. Further, skin irritation study and transepidermal water loss (TEWL) measurement using guinea pig skin in vivo indicated that skin disruption induced by SHS treatment is self-limited and can be recovered with time and efficiently. SHS can offer a safe, effective, and sustained skin delivery of hydrophilic biomacromolecules and presents a promising platform technology for a wide range of cosmetic and medical applications.


Subject(s)
Haliclona/metabolism , Skin/metabolism , Animals , Epidermis/metabolism , Female , Guinea Pigs , Hydrophobic and Hydrophilic Interactions , Mice, Inbred BALB C , Microscopy, Confocal , Microscopy, Electron, Scanning , Molecular Weight , Skin Absorption , Water/metabolism
13.
J Struct Biol ; 193(1): 67-74, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26672719

ABSTRACT

Marine sponge spicules are silicate fibers with an unusual combination of fracture toughness and optical light propagation properties due to their micro- and nano-scale hierarchical structure. We present optical measurements of the elastic properties of Tethya aurantia and Euplectella aspergillum marine sponge spicules using non-invasive Brillouin and Raman laser light scattering, thus probing the hierarchical structure on two very different scales. On the scale of single bonds, as probed by Raman scattering, the spicules resemble a combination of pure silica and mixed organic content. On the mesoscopic scale probed by Brillouin scattering, we show that while some properties (Young's moduli, shear moduli, one of the anisotropic Poisson ratios and refractive index) are nearly the same as those of artificial optical fiber, other properties (uniaxial moduli, bulk modulus and a distinctive anisotropic Poisson ratio) are significantly smaller. Thus this natural composite of largely isotropic materials yields anisotropic elastic properties on the mesoscale. We show that the spicules' optical waveguide properties lead to pronounced spontaneous Brillouin backscattering, a process related to the stimulated Brillouin backscattering process well known in artificial glass fibers. These measurements provide a clearer picture of the interplay of flexibility, strength, and material microstructure for future functional biomimicry.


Subject(s)
Porifera/chemistry , Silicon Dioxide/chemistry , Animals , Elastic Modulus , Elasticity , Refractometry
14.
J Cutan Pathol ; 42(3): 164-172, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25355400

ABSTRACT

BACKGROUND: The early stages of follicular mycosis fungoides (FMF) have not been described previously in the literature. OBJECTIVE: Our goal was to better categorize the clinicopathologic features of early stages of FMF. METHODS: The clinical notes of patients with a diagnosis of FMF seen during the previous 5 years were reviewed to identify any cases that at presentation had only hyperkeratotic follicular lesions. RESULTS: Eight patients (five male, three female) with a mean age of 55.4 years were enrolled. Noteworthy, FMF was not a clinical consideration in any of these patients initially. Patients presented with disseminated, slightly erythematous, hyperkeratotic, spiky follicular papules which, histopathologically, showed hyperkeratotic columns protruding from follicular plugging in concert with selective infiltration of the infundibular epithelium by atypical, mostly CD4+, lymphocytes. T-cell clonality was demonstrated in four of eight cases. The mean duration of the lesions before diagnosis was 17.1 months. The course was indolent in most of the cases (median follow up: 18 months), whilst progression to overt FMF was noted in two patients. LIMITATIONS: The number of cases is small and follow up relatively short. CONCLUSIONS: Spiky FMF is a deceptive clinicopathologic presentation of FMF that has been poorly described and that can mimic numerous follicular disorders.


Subject(s)
Mycosis Fungoides/pathology , Skin Neoplasms/pathology , Abnormalities, Multiple/pathology , Aged , Biopsy , Darier Disease/pathology , Diagnosis, Differential , Disease Progression , Eyebrows/abnormalities , Eyebrows/pathology , Female , Humans , Immunophenotyping , Male , Middle Aged , Mycosis Fungoides/genetics , Mycosis Fungoides/immunology , Skin Neoplasms/genetics , Skin Neoplasms/immunology , T-Lymphocytes/pathology
15.
Chemistry ; 20(17): 4956-65, 2014 Apr 22.
Article in English | MEDLINE | ID: mdl-24633700

ABSTRACT

Organisms of the phylum Porifera, that is, sponges, utilize enzymatic hydrolysis to concatenate bioavailable inorganic silicon to produce lightweight, strong, and often flexible skeletal elements called spicules. In their optical transparency, these remarkable biomaterials resemble fused silica, despite having been formed under ambient marine biological conditions. Although previous studies have elucidated the chemical mechanisms of spicule formation and revealed the extensive hydration of these glasses, their precise composition and local and medium-range structures had not been determined. We have employed a combination of compositional analysis, (1) H and (29) Si solid-state nuclear magnetic resonance spectroscopy, and synchrotron X-ray total scattering to characterize spicule-derived silica produced by the demosponge Tethya aurantia. These studies indicate that the materials are highly hydrated, but in an inhomogeneous manner. The spicule-derived silica is, on average, perfectly dense for the given extent of hydration and regions of fully condensed and unstrained SiO networks persist throughout each monolithic spicule. To accommodate chemical strain and defects, the extensive hydration is concentrated in distinct regions that give rise to mesostructural features. The chemistry responsible for producing spicule silica resembles hydrolytic sol-gel processing, which offers exceptional control over the precise local atomic arrangement of materials. However, the specific processing involved in forming the sponge spicule silica further results in regions of fully condensed silica coexisting with regions of incomplete condensation. This mesostructure suggests a mechanism for atomistic defect tolerance and strain relief that may account for the unusual mechanical properties of the biogenic spicules.


Subject(s)
Porifera/chemistry , Silicon Dioxide/chemistry , Animals , Magnetic Resonance Spectroscopy , Porifera/ultrastructure
16.
Front Zool ; 11(1): 65, 2014.
Article in English | MEDLINE | ID: mdl-25642279

ABSTRACT

INTRODUCTION: The calcareous shells of brachiopods offer a wealth of informative characters for taxonomic and phylogenetic investigations. In particular scanning electron microscopy (SEM) has been used for decades to visualise internal structures of the shell. However, to produce informative SEM data, brachiopod shells need to be opened after chemical removal of the soft tissue. This preparation occasionally damages the shell. Additionally, skeletal elements of taxonomic/systematic interest such as calcareous spicules which are loosely embedded in the lophophore and mantle connective tissue become disintegrated during the preparation process. RESULTS: Using a nondestructive micro-computed tomography (µCT) approach, the entire fragile endoskeleton of brachiopods is documented for the first time. New insights on the structure and position of tissue-bound skeletal elements (spicules) are given as add ons to existing descriptions of brachiopod shell anatomy, thereby enhancing the quality and quantity of informative characters needed for both taxonomic and phylogenetic studies. Here, we present five modern, articulated brachiopods (Rectocalathis schemmgregoryi n. gen., n. sp., Eucalathis sp., Gryphus vitreus, Liothyrella neozelanica and Terebratulina retusa) that were X-rayed using a Phoenix Nanotom XS 180 NF. We provide links to download 3D models of these species, and additional five species with spicules can be accessed in the Supplemental Material. In total, 17 brachiopod genera covering all modern articulated subgroups and 2 inarticulated genera were X-rayed for morphological analysis. Rectocalathis schemmgregoryi n. gen., n. sp. is fully described. CONCLUSION: Micro-CT is an excellent non-destructive tool for investigating calcified structures in the exo- and endoskeletons of brachiopods. With high quality images and interactive 3D models, this study provides a comprehensive description of the profound differences in shell anatomy, facilitates the detection of new delicate morphological characters of the endoskeleton and gives new insights into the body plan of modern brachiopods.

17.
J Nematol ; 46(2): 125-9, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24987164

ABSTRACT

A new species, Goffartia phalacra n. sp. is described and illustrated. The body is thin and slender with L = 511 to 646 µm; a = 37.1 to 47.4; b = 4.8 to 6; c = 2.6 to 4.8; c' = 13.6 to 32.8; V = 40% to 49% in females. Males are smaller but similar to females and the posterior region is strongly curved. The species is characterized by a tubular stoma, a smooth round lip region, anterior pharynx much smaller than posterior pharynx, two pairs of unicellular glands associated with the vagina, and males with a broad keel-shaped gubernaculum. G. phalacra n. sp. can be differentiated from all other species of the genus by its lip region and the structure of the gubernaculum. This is the first instance of a species of Goffartia occurring in a terrestrial habitat and the first report of a species from India.

18.
J Proteomics ; 296: 105126, 2024 03 30.
Article in English | MEDLINE | ID: mdl-38364902

ABSTRACT

The hard shells of mollusks are products of biomineralization, a distinctive feature of the Cambrian explosion. Despite our understanding of shell structure and mechanical properties, their origin remains mysterious. In addition to their shell plates, most chitons have calcium deposits on their girdles. However, the similarity of these two mineralized structures still needs to be determined, limiting our comprehension of their origins. In our study, we analyzed the matrix proteins in the spicules of chiton (Acanthopleura loochooana) and compared them with the matrix proteins in the shells of the same species. Proteomics identified 96 unique matrix proteins in spicules. Comparison of biomineralization-related matrix proteins in shell plates and spicules revealed shared proteins, including carbonic anhydrases, tyrosinase-hemocyanin, von Willebrand factor type A, cadherin, and glycine-rich unknown proteins. Based on similarities in key matrix proteins, we propose that spicules and shell plates originated from a common mineralization system in their ancestral lineage, suggesting the existence of a common core or toolkit of matrix proteins among calcifying organisms. SIGNIFICANCE: In this study, we try to understand the types and diversity of matrix proteins in the biomineralization of chiton shell plates and spicules. Through a comparative analysis, we seek insights into the core biomineralization toolkit of ancestral mollusks. To achieve this, we conducted LC-MS/MS and RT-qPCR analyses to identify the types and relative expression levels of matrix proteins in both shell plates and spicules. The analysis revealed 96 matrix proteins in the spicules. A comparison of biomineralization-related matrix proteins in shell plates and spicules from the same species revealed shared proteins including many unknown proteins unique to chitons. Blast searching reveals a universal conservation of these proteins among other chitons. Hence, we propose that spicules and shell plates originated from a common mineralization system in their ancestral lineage. Our work provides a molecular basis for studying biomineralization in polyplacophoran mollusks and understanding biomineralization evolution. In addition, it identifies potential matrix proteins that could be applied to control crystal growth.


Subject(s)
Biomineralization , Polyplacophora , Animals , Chromatography, Liquid , Tandem Mass Spectrometry , Proteins/analysis
19.
Int J Paleopathol ; 46: 16-23, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38865933

ABSTRACT

OBJECTIVES: To determine which types of bone lesion (spicules, lobules, porous bone) in the maxillary sinus indicate sinusitis METHODS: Subadjacent dental disease is a cause of maxillary sinusitis; if a lesion type indicates sinusitis it should be more common above diseased posterior maxillary teeth than a lesion type that is not indicative of sinusitis. The study sample is a British Mediaeval human skeletal collection. RESULTS: Porous bone lesions (chiefly new bone deposits) in maxillary sinuses are associated with subadjacent dental disease; spicules/lobules of bone in the sinus are not. CONCLUSIONS: The results support the idea that porous lesions indicate sinusitis but the spicules/lobules may not. Spicules, lobules and porous lesions within the maxillary sinus should be analysed separately in biocultural studies; it would be prudent to regard only the porous lesions as indicative of sinusitis. SIGNIFICANCE: Maxillary sinusitis is commonly used as a health indicator in palaeopathology, and spicular deposits are generally the most common type of alterations. By assuming that they are indicative of sinusitis we may have been greatly overestimating the prevalence of bony sinusitis in the past. LIMITATIONS: These conclusions are provisional. Further work on larger, more diverse samples, together with more detailed anatomical studies on lesion location and structure is ongoing.


Subject(s)
Maxillary Sinus , Maxillary Sinusitis , Humans , Maxillary Sinus/pathology , Maxillary Sinus/diagnostic imaging , Maxillary Sinusitis/pathology , Maxillary Sinusitis/diagnostic imaging , Chronic Disease , History, Medieval , Paleopathology
20.
Biomimetics (Basel) ; 9(7)2024 Jun 27.
Article in English | MEDLINE | ID: mdl-39056834

ABSTRACT

Sponges (phylum Porifera) were among the first metazoans on Earth, and represent a unique global source of highly structured and diverse biosilica that has been formed and tested over more than 800 million years of evolution. Poriferans are recognized as a unique archive of siliceous multiscaled skeletal constructs with superficial micro-ornamentation patterned by biopolymers. In the present study, spicules and skeletal frameworks of selected representatives of sponges in such classes as Demospongiae, Homoscleromorpha, and Hexactinellida were desilicified using 10% HF with the aim of isolating axial filaments, which resemble the shape and size of the original structures. These filaments were unambiguously identified in all specimens under study as F-actin, using the highly specific indicators iFluor™ 594-Phalloidin, iFluor™ 488-Phalloidin, and iFluor™ 350-Phalloidin. The identification of this kind of F-actins, termed for the first time as silactins, as specific pattern drivers in skeletal constructs of sponges opens the way to the fundamental understanding of their skeletogenesis. Examples illustrating the biomimetic potential of sophisticated poriferan biosilica patterned by silactins are presented and discussed.

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