Search Results (15)

(1) Background: Cerebral magnetic resonance imaging has reported new cerebral ischemic lesions after left atrial appendage (LAA) closure in about one- third of patients. Stroke occurs predominantly periprocedurally. This study evaluated the characteristics of embolized debris captured by the SENTINEL^TM cerebral embolic protection system in patients undergoing LAA closure; (2) Methods: Sixty filters of 30 consecutive patients undergoing LAA closure with the WATCHMAN FLX^TM device were collected and captured debris was analyzed by histopathology and histomorphometry. Clinical outcome measures were disabling and non-disabling stroke within 72 h; (3) Results: In most filters, no material was captured. The predominant captured debris was acute or organized thrombi. The most common pattern was acute fibrin-rich thrombus, which was detected in 11/30 (33.3%) patients. Particles of heart tissue were seen in 6/30 (20%) patients, and foreign material was seen in one (3.3%) patient. The number of particles ranged from 0 to 52 per patient with a maximum of 31 in the distal and 21 in the proximal filter. Particle diameter ranged from 131 to 2614 µm. By logistic regression analysis, only protected time remained a multivariable predictor for larger particles (p = 0.039). There was no disabling or non-disabling stroke. Compared to transfemoral aortic valve replacement, the number of particles is only about 1.5%. (4) Conclusion: LAA occlusion with the WATCHMAN FLX^TM was associated with a very low number of embolized particles captured with the double-filter SENTINEL^TM embolic protection system and no periprocedural stroke. Full article

This study describes two new species of the subgenus Desmoscolex (Nematoda: Desmoscolecidae) from deep-sea habitats in the Ulleung Basin, the East Sea, Korea, located in the NorthWest Pacific Ocean. Both species exhibit cephalic setae with wing-like appendages—a rare trait documented in only a few species of this subgenus. Desmoscolex (Desmoscolex) globiceps sp. nov. is characterized by a rounded head covered with concretion particles, wing-like cephalic setae equipped with thin, flap-like membranes, and oval amphidial fovea that cover most of the head. The body is composed of 17 main rings, bearing slender somatic setae that taper to an open tip and a conical terminal ring that elongates to a short spinneret. Females of this species lack subventral setae on the 14th main ring. Desmoscolex (Desmoscolex) ovaliceps sp. nov. features an oval head covered with foreign particles, wing-like cephalic setae with thin, flap-like membranes, and oval amphids encompassing much of the head. This species also has a body with 17 main rings, with subdorsal setae gradually tapering toward the tip, which is slightly differentiated from the rest, and shorter subventral setae ending with an open distal tip. The terminal ring is conical, slightly tapered, and terminates in an uncovered spinneret. Detailed morphological descriptions of both species are provided, incorporating scanning electron microscopy (SEM) and differential interference contrast (DIC) images. A comparative analysis with previously described taxa is included, along with a pictorial key to assist in the identification of related species, contributing to a deeper understanding of morphological diversity within the subgenus Desmoscolex. Full article

The primary cilium is a microtubule-based sensory organelle that plays a critical role in signaling pathways and cell cycle progression. Defects in the structure and/or function of the primary cilium result in developmental diseases collectively known as ciliopathies. However, the constituents and regulatory mechanisms of the primary cilium are not fully understood. In recent years, the activity of the epigenetic modifier SMYD3 has been shown to play a key role in the regulation of cell cycle progression. However, whether SMYD3, a histone/lysine methyltransferase, contributes to the regulation of ciliogenesis remains unknown. Here, we report that SMYD3 drives ciliogenesis via the direct and indirect regulation of cilia-associated components. We show that SMYD3 is a novel component of the distal appendage and is required for centriolar appendage assembly. The loss of SMYD3 decreased the percentage of ciliated cells and resulted in the formation of stumpy cilia. We demonstrated that SMYD3 modulated the recruitment of centrosome proteins (Cep164, Fbf1, Ninein, Ttbk2 and Cp110) and the trafficking of intraflagellar transport proteins (Ift54 and Ift140) important for cilia formation and maintenance, respectively. In addition, we showed that SMYD3 regulated the transcription of cilia genes and bound to the promoter regions of C2cd3, Cep164, Ttbk2, Dync2h1 and Cp110. This study provides insights into the role of SMYD3 in cilia biology and suggests that SMYD3-mediated cilia formation/function may be relevant for cilia-dependent signaling in ciliopathies. Full article

Mites, the second largest arthropod group, exhibit rich phenotypic diversity in the development of appendages (legs). For example, the fourth pair of legs (L4) does not form until the second postembryonic developmental stage, namely the protonymph stage. These leg developmental diversities drive body plan diversity in mites. However, little is known about the mechanisms of leg development in mites. Hox genes, homeotic genes, can regulate the development of appendages in arthropods. Three Hox genes, Sex combs reduced (Scr), Fushi tarazu (Ftz) and Antennapedia (Antp), have previously been shown to be expressed in the leg segments of mites. Here, the quantitative real-time reverse transcription PCR shows that three Hox genes are significantly increased in the first molt stage. RNA interference results in a set of abnormalities, including L3 curl and L4 loss. These results suggest that these Hox genes are required for normal leg development. Furthermore, the loss of single Hox genes results in downregulating the expression of the appendage marker Distal-less (Dll), suggesting that the three Hox genes can work together with Dll to maintain leg development in Tetranychus urticae. This study will be essential to understanding the diversity of leg development in mites and changes in Hox gene function. Full article

Agasicles hygrophila Selman and Vogt (Coleoptera: Chrysomelidae) is the key natural enemy of Alternanthera philoxeroides (Mart.) Griseb, an invasive weed worldwide. To understand the morphology of A. hygrophila and further explore the specific host localization mechanism, scanning electron microscopy was used to observe and study the morphological characteristics of sensilla on the head appendages, tarsi, and external genital segments of A. hygrophila. Twelve types and forty-six subtypes of sensilla were observed. These contain various types of head appendices, including sensilla chaetica, sensilla trichodea, sensilla basiconca, sensilla coeloconica, sensilla styloconica, Böhm bristles, sensilla campaniform, sensilla terminal, sensilla dome, sensilla digit-like, sensilla aperture, and many subtypes. A new type of sensor was reported for the first time, which may be related to host plant recognition. This sensor was located on the distal segment of the maxillary palps of A. hygrophila and was named as sensilla petal-shaped based on its morphological characteristics. Sensilla chaetica, sensilla trichodea, and sensilla basiconca are also found on the tarsi and external genital segments. In addition, sensilla basiconica 4, sensilla coeloconica 1 and 2, sensilla styloconica 2, Böhm bristles 2, and sensilla campaniform 1 were only found in females. On the contrary, sensilla styloconica 3, sensilla coeloconica 3, and sensilla dome were only found in males. Numbers and sizes of the sensilla were also different between males and females. The potential functions related to structure were discussed in comparison with previous investigations on beetles and other monophagous insects. Our results provide a microscopic morphological basis for further research on the localization and recognition mechanism of A. hygrophila and its obligate host. Full article

Radiodonta, an extinct stem-euarthropod group, has been considered as the largest predator of Cambrian marine ecosystems. As one of the radiodont-bearing Konservat-Lagerstätten, the Guanshan biota (South China, Cambrian Stage 4) has yielded a diverse assemblage of soft-bodied and biomineralized taxa that are exclusive to this exceptional deposit. “Anomalocaris” kunmingensis, the most abundant radiodont in the Guanshan biota, was originally assigned to Anomalocaris within the Anomalocarididae. Despite this taxon being formally assigned to the family Amplectobeluidae more recently, its generic assignment remains uncertain. Here, we present new materials of “Anomalocaris” kunmingensis from the Guanshan biota, and reveal that the frontal appendages possess two enlarged endites; all endites bear one posterior auxiliary spine and up to four anterior auxiliary spines; three robust dorsal spines and one terminal spine protrude from the distal part. These new observations, allied with anatomical features illustrated by previous studies, allow us to assign this taxon to a new genus, Guanshancaris gen. nov. Brachiopod shell bearing embayed injury and incomplete trilobites, associated with frontal appendages in our specimens, to some extent confirm Guanshancaris as a possible durophagous predator. The distribution of amplectobeluids demonstrates that this group is restricted to Cambrian Stage 3 to Drumian, and occurs across South China and Laurentia within the tropics/subtropics belt. Moreover, the amount and abundance of amplectobeluids evidently decreases after the Early–Middle Cambrian boundary, which indicates its possible preference for shallow water, referring to its paleoenvironmental distribution and may be influenced by geochemical, tectonic, and climatic variation. Full article

Floral symmetry studies often focus on the development of monosymmetric and polysymmetric flowers, whereas asymmetric flowers and their position and function within the inflorescence structure are largely neglected. Cannaceae is one of the few families that possesses truly asymmetric flowers, serving as a model to study the characters and mechanisms involved in the development of floral asymmetry and its context within the developing and mature inflorescence. In this study, inflorescence structure and floral morphology of normal asymmetric flowers and 16 aberrant flower collections from Canna indica L. and C. glauca L. were photographed, analyzed, and compared with attention to stamen petaloidy, floral symmetry, and inflorescence branching patterns anterior and posterior to the aberrant flower. In comparison with normal flowers, the aberrant flowers are arranged into abnormal partial florescences, and vary in floral symmetry, orientation, and degree of androecial petaloidy. The appendage of the fertile stamen is universally located distal from the higher order bract, indicating an underlying influence of inflorescence architecture. A synthetic model is proposed to explain the relationship between floral symmetry and inflorescence structure. Data from the observation of aberrant phenotypes strongly support the hypothesis that irregular petaloidy of the stamens is correlated with an asymmetric morphogenetic field within the inflorescence that contributes to the overall floral asymmetry in Canna flowers. Full article

The primary cilium is found in most mammalian cells and plays a functional role in tissue homeostasis and organ development by modulating key signaling pathways. Ciliopathies are a group of genetically heterogeneous disorders resulting from defects in cilia development and function. Patients with ciliopathic disorders exhibit a range of phenotypes that include nephronophthisis (NPHP), a progressive tubulointerstitial kidney disease that commonly results in end-stage renal disease (ESRD). In recent years, distal appendages (DAPs), which radially project from the distal end of the mother centriole, have been shown to play a vital role in primary ciliary vesicle docking and the initiation of ciliogenesis. Mutations in the genes encoding these proteins can result in either a complete loss of the primary cilium, abnormal ciliary formation, or defective ciliary signaling. DAPs deficiency in humans or mice commonly results in NPHP. In this review, we outline recent advances in our understanding of the molecular functions of DAPs and how they participate in nephronophthisis development. Full article

Hand injuries often result in significant functional impairments and are rarely completely restored. The spontaneous regeneration of injured appendages, which occurs in salamanders and newts, for example, has been reported in human fingertips after distal amputation, but this type of regeneration is rare in mammals and is incompletely understood. Here, we study fingertip regeneration by amputating murine digit tips, either distally to initiate regeneration, or proximally, causing fibrosis. Using an unbiased microarray analysis, we found that digit tip regeneration is significantly associated with hair follicle differentiation, Wnt, and sonic hedgehog (SHH) signaling pathways. Viral over-expression and genetic knockouts showed the functional significance of these pathways during regeneration. Using transgenic reporter mice, we demonstrated that, while both canonical Wnt and HH signaling were limited to epidermal tissues, downstream hedgehog signaling (through Gli) occurred in mesenchymal tissues. These findings reveal a mechanism for epidermal/mesenchyme interactions, governed by canonical hedgehog signaling, during digit regeneration. Further research into these pathways could lead to improved therapeutic outcomes after hand injuries in humans. Full article

We analyzed clinical experience with percutaneous closure of instances of left atrial appendage with thrombus (LAAT) irresponsive to antithrombotic therapy in patients treated in three high-volume cardiology centers. Clinical and procedural data regarding consecutive patients who underwent percutaneous left atrial appendage closure (PLAAC) due to LAAT were retrospectively analyzed. The study population consisted of 17 patients (11 men; 68 ± 14 years; CHA₂DS₂VASC 4.7 ± 1.9; HASBLED 3 (0–5)) with LAAT confirmed by transesophageal echocardiography, and included 5 patients with mechanical heart valves. Most of the patients (94.1%) received anticoagulation therapy before PLAAC. All LAATs were located in distal portions of the appendage and occupied less than 30% of its volume. Occluding-device implantation was successful in 17 patients; in one, a residual leak was disclosed. Appropriate positioning of occluders required more than 1 attempt in 6 individuals (35.3%); in 3 others (17.6%), the subjects’ devices had contact with thrombi. No procedural complications were noted. Midterm follow-up (median: 10 months) revealed no procedure-related complications or clinically diagnosed thromboembolism. Transesophageal echocardiography (TEE) performed after six months revealed device-related thrombus in one patient. We concluded that LAAT irresponsive to antithrombotic therapy might be effectively treated with PLAAC, even in patients with mechanical-valve prostheses. Full article

Palaeoannelida Weigert and Bleidorn, 2016 is an old clade branching off at the base of the Annelida radiation. It includes two morphologically and ecological divergent groups of sedentary burrowers and tube-dwellers: Magelonidae Cunningham and Ramage, 1888, and Oweniidae Rioja, 1917. Magelonids are characterised by a flattened, shovel-shaped prostomium and a pair of ventral papillated palps. Oweniids have simplified bodies lacking parapodia or appendages and are easily distinguished by the presence of oval patches of packed uncini, each with two distal curved teeth. The present review aims to summarise available information about the diversity of forms and life strategies displayed in the group, providing some guidelines for species identification and the techniques commonly used for their study. In addition, the assumed geographic distributions of some taxa are critically discussed. A brief introduction about the evolutionary relationships, systematics, and taxonomic history is given for both Magelonidae and Oweniidae. The motivation of this review is to highlight the main knowledge gaps from a taxonomic, methodological, and geographic perspective, aiming at stimulating further research into members of this clade. Full article

The regeneration of paired appendages in certain fish and amphibian lineages is a well established and extensively studied regenerative phenomenon. The teleost fin is comprised of a proximal endoskeletal part (considered homologous to the Tetrapod limb) and a distal exoskeletal one, and these two parts form their bony elements through different ossification processes. In the past decade, a significant body of literature has been generated about the biology of exoskeletal regeneration in zebrafish. However, it is still not clear if this knowledge can be applied to the regeneration of endoskeletal parts. To address this question, we decided to compare endo- and exoskeletal regenerative capacity in zebrafish (Danio rerio) and mudskippers (Periophthalmus barbarous). In contrast to the reduced endoskeleton of zebrafish, Periophthalmus has well developed pectoral fins with a large and easily accessible endoskeleton. We performed exo- and endoskeletal amputations in both species and followed the regenerative processes. Unlike the almost flawless exoskeletal regeneration observed in zebrafish, regeneration following endoskeletal amputation is often impaired in this species. This difference is even more pronounced in Periophthalmus where we could observe no regeneration in endoskeletal structures. Therefore, regeneration is regulated differentially in the exo- and endoskeleton of teleost species. Full article

Cilia and flagella are evolutionarily conserved, membrane-bound, microtubule-based organelles on the surface of most eukaryotic cells. They play important roles in coordinating a variety of signaling pathways during growth, development, cell mobility, and tissue homeostasis. Defects in ciliary structure or function are associated with multiple human disorders called ciliopathies. These diseases affect diverse tissues, including, but not limited to the eyes, kidneys, brain, and lungs. Many processes must be coordinated simultaneously in order to initiate ciliogenesis. These include cell cycle, vesicular trafficking, and axonemal extension. Centrioles play a central role in both cell cycle progression and ciliogenesis, making the transition between basal bodies and mitotic spindle organizers integral to both processes. The maturation of centrioles involves a functional shift from cell division toward cilium nucleation which takes place concurrently with its migration and fusion to the plasma membrane. Several proteinaceous structures of the distal appendages in mother centrioles are required for this docking process. Ciliary assembly and maintenance requires a precise balance between two indispensable processes; so called assembly and disassembly. The interplay between them determines the length of the resulting cilia. These processes require a highly conserved transport system to provide the necessary substances at the tips of the cilia and to recycle ciliary turnover products to the base using a based microtubule intraflagellar transport (IFT) system. In this review; we discuss the stages of ciliogenesis as well as mechanisms controlling the lengths of assembled cilia. Full article

Pulmonary arterial hypertension (PAH; MIM 600799) is frequently associated with concomitant diseases, including congenital heart disease. 6% of patients with PAH show a family history of the disease [hereditary PAH (HPAH)], with the major genetic determinants of HPAH being heterozygous germline mutations in the bone morphogenetic protein type II receptor (BMPR2). We present the case of a 38-year-old woman of Indian descent; initially admitted with progressive dyspnea [New York Heart Association (NYHA) class III]. The results of the proband’s clinical assessments are presented here. Cardiac catheterization confirmed idiopathic PAH with severe right ventricular hypertrophy associated with pulmonary arteriopathy. Initial treatment comprised the dual endothelin receptor antagonist, bosentan, furosemide, warfarin and intravenous infusion of prostaglandin I2 (PGI2) for 3 days. Despite this, the patient died of pulmonary hemorrhagic edema and cardiogenic shock after 6 days of intensive care. After relatives’ consent, post mortem assessments confirmed a diagnosis of PAH; the heart displayed significant right ventricular hypertrophy and it was particularly noted that the right atrial appendage had undergone extreme dilation. Pulmonary arteriopathy was characterized by medial hypertrophy, arterialization of muscular arteries and muscularization of non-muscularized distal arteries. Molecular genetic analyses revealed the presence of cis-mutations in the BMPR2 gene (p.Cys123Arg and p.Arg332X). Cosegregation studies were not available. Our findings suggest that mutations of the BMPR2 gene gave rise to the onset of PAH in this patient and that the severity of the onset and progression could be attributed to the presence of multiple mutations in a genedosage manner. Full article

This paper reports two cases of acrometastasis to the hands. The first case involved a 78-year-old woman with a permeative osteolytic lesion in her proximal second metacarpal. A biopsy of this lesion suggested a diagnosis of non-small-cell lung carcinoma with secondary osseous metastasis. This was the first presentation of the woman’s primary diagnosis. A single 8-Gy fraction of palliative radiotherapy was delivered to the patient’s left hand. The treatment proved successful: the woman soon experienced pain relief and regained the use of her hand. The second case involved a 69- year-old woman with extensive lytic destruction involving the proximal two thirds of her third metacarpal. This patient had been diagnosed with carcinoma of the breast in 1990. She also received a single 8-Gy fraction of radiation, which improved both her pain and her hand mobility. An extensive review of the literature uncovered 257 previously reported cases of acrometastasis. Articles were analyzed based on age and sex of the patient, site of the primary carcinoma, metastatic locations within the hand and affected appendage or appendages, the treatment given, and the patient’s length of survival. Men were almost twice as likely to experience acrometastasis as women, and the median age of the patients overall was 58 years (range: 18 months–91 years). Lung, kidney, and breast carcinoma were the three most prevalent primary diagnoses reported in the literature. Cancers of the colon, stomach, liver, prostate, and rectum affected the remainder of the population. Overall, the right hand was more often host to the metastatic lesions. In addition, almost 10% of the patients experienced lesions in both hands. The third finger was the digit most affected by osseous metastases reported in the literature. Lesions of the thumb, fourth finger, second finger, and fifth finger were less commonly reported. The region of the digit most often affected within the patient population was the distal phalanx. The metacarpal bones, proximal phalanges, and middle phalanges comprised the remainder of the four most frequent acrometastatic sites. In the literature, single lesions were more prevalent than multiple bony lesions. Based on the reported cases, amputation appeared to be the preferred method of treatment. Radiation, excision, and systemic therapy were the next most frequently used treatments. Patient survival was not well documented within the literature. However, the median survival of patients in the reported cases was 6 months. Thus, our review suggested that a diagnosis of hand metastasis is an indication of poor prognosis. This report serves to emphasize the importance of properly diagnosing acrometastases. Identifying and effectively treating these metastases in a timely manner can lead to a dramatic improvement in a patient’s quality of life. Full article