Site Of Penetration Research Articles

Multi-targeted nanogel drug delivery system alleviates neuroinflammation and promotes spinal cord injury repair.

Multi-targeted nanogel drug delivery system alleviates neuroinflammation and promotes spinal cord injury repair.

Identification of INOSITOL PHOSPHORYLCERAMIDE SYNTHASE 2 (IPCS2) as a new rate-limiting component in Arabidopsis pathogen entry control.

INOSITOL PHOSPHORYLCERAMIDE SYNTHASE 2 (IPCS2) is involved in the biosynthesis of complex sphingolipids at the trans-Golgi network (TGN). Here, we demonstrate a role of IPCS2 in penetration resistance against non-adapted powdery mildew fungi. A novel ipcs2W205* mutant was recovered from a forward genetic screen for Arabidopsis plants with enhanced epidermal cell entry success of the non-adapted barley fungus Blumeria graminis f. sp. hordei (Bgh). A yeast complementation assay and a sphingolipidomic approach revealed that the ipcs2W205* mutant represents a knock-out and lacks IPCS2-specific enzymatic activity. Further mutant analyses suggested that IPCS2-derived glycosyl inositol phosphorylceramides (GIPCs) are required for cell entry control of non-adapted fungal intruders. Confocal laser scanning microscopy (CLSM) studies indicated that upon pathogen attack, IPCS2 remains at the TGN to produce GIPCs, while focal accumulation of the defense cargo PENETRATION 3 (PEN3) at Bgh penetration sites was reduced in the ipcs2W205* mutant background. Thus, we propose a model in which sorting events at the TGN are facilitated by complex sphingolipids, regulating polar secretion of PEN3 to host-pathogen contact sites to terminate fungal ingress.

Stylostome of Leptotrombidium myotis larvae (Ewing, 1929) (Acariformes, Trombiculidae) feeding on two different bat species (Vespertilionidae)

Larvae of Leptotrombidium myotis (Ewing, 1929) and their stylostome on the bats Plecotus ognevi Kishida, 1927 (Buryatia) and Myotis davidii (Peters, 1869) (Kazakhstan) were studied with scanning (SEM) and transmission (TEM) electron microscopy and histological methods. The stylostome of this trombiculid species in these two different host species was identically organized and is composed of the proximal eosinophilic cone, to which the larval chelicerae are cemented; the main hyaline-like, immunologically-inert unstained portion; and the distal azurophil region. The total length of the stylostome may reach 200 µm. Imaging by TEM shows that the stylostome is built of a homogeneous substance, which does not have any structurally different layers. The axial canal, around 10 µm in width, opens freely to the subjacent tissue and may contain different host cells and their debris. The skin inflammatory response to the parasites’ impact in these two host species appears to be different in its character and intensity. In P. ognevi, the epidermis is dissolved at the site of the larval penetration but peripherally, it undergoes hyperplasia. The inflammatory reaction is of moderate intensity with the presence of neutrophil leucocytes, macrophages and mast cells in the focus accompanied by dilation of the peripheral capillaries and edema. Conversely, in M. davidii, a strong reaction is observed with a total dissolution of the epidermis at the location of larval feeding, intensive hemorrhages in the dermis, and formation of a scab on the skin surface, formed of fused, necrotic inflammatory and epidermal cells that together contribute to the strong lesion in the skin. In this type of skin reaction, neutrophil leucocytes are predominant but mast cells are mostly lacking. Owing to this finding, it may be assumed that M. davidii from Kazakhstan has evolutionary evolved a strong resistance to feeding of this trombiculid species and may serve as a transitional agent of infecting pathogens.

Evaluating the Characteristics of the Totally Implantable Venous Access Device in Cancer Patients Using Fluorodeoxyglucose-PET/CT in the Absence of Suspected Catheter-Related Infections.

This study evaluated the fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) imaging features associated with the totally implantable venous access device (TIVAD) in cancer patients. We conducted a retrospective single-institution review of TIVAD placements between January 2016 and December 2020. Among these, we identified cases where FDG-PET/CT was performed to monitor malignant tumors after TIVAD placement. Increased accumulation was evaluated based on the site, TIVAD approach, and indwelling time. In total, 145 TIVAD placements were identified in 144 patients. The median number of FDG-PET/CT examinations was two (range: 1-14). Sites of increased accumulation were found in the vein of catheter penetration (8.3%) and port (1.4%). Increased accumulations were observed only with the subclavian approach. In patients with an indwelling time > 1 month, all accumulations were observed in the vein of catheter penetration (7.9%). Increased FDG accumulation associated with the TIVAD is not uncommon. A small thrombus with some reactive processes at the vein penetration site may be responsible for the increased accumulation.

A wearable antifouling electrochemical sensor integrated with an antimicrobial microneedle array for uric acid detection in interstitial fluid.

A wearable antifouling electrochemical sensor integrated with an antimicrobial microneedle array for uric acid detection in interstitial fluid.

Barley leaf cell-wall responses to the penetration by adapted and nonadapted powdery mildew fungi revealed with the thermal-source based Fourier transform infrared microspectroscopy and focal plane array

Infrared microspectroscopy allows for detailed characterization of functional groups at subcellular levels in plants. In this study, barley leaves were inoculated with Blumeria graminis f. sp. hordei (Bgh, adapted) and B. graminis f. sp. tritici (Bgt, nonadapted). Globar-based transmission Fourier transform infrared (gFTIR) microspectroscopy equipped with an upgraded high-resolution focal plane array (FPA) detector which enabled the rapid acquisition of high magnification imaging with a 3.3-μm × 3.3-μm capacity, was employed to quantitatively analyse the cell wall (CW) modification over individual leaf cells in response to attempted penetration at 24 hours post-inoculation. Univariate and multivariate analyses of gFTIR spectra revealed distinct changes in several CW functional groups upon attempted penetration by Bgt, with significant increases in the integrated areas of cellulose, hemicellulose, methyl-esterified pectins and lipid regions compared to cells without penetration. Notably, neither guaiacyl (G) nor syringyl (S) lignin increased significantly in CWs near Bgt penetration sites relative to nonpenetrating controls, though the G/S ratio was higher than in Bgh-penetrated sites. These findings suggest early and rapid CW modifications occur during the nonhost resistance to Bgt. This study also confirms previous results obtained using synchrotron-based FTIR (sFTIR), demonstrating that both gFTIR and sFTIR are valuable for studying plant CW apposition, with gFTIR being more accessible and rapid for imaging over large areas with compatible quality and resolution to sFTIR.

Clinical outcomes of modified left ventricular assist device driveline management.

Left ventricular assist devices (LVADs) are implanted in patients with heart failure to support cardiac circulation. However, no standardized methods have been established for LVAD driveline exit site management for the prevention of infections. Therefore, this study evaluated the efficacy of modified driveline management compared with that of conventional driveline management. We retrospectively assessed the outcomes of 262 patients who underwent continuous-flow LVAD implantation between January 2005 and March 2023 at Osaka University in Japan. In conventional driveline management, an LVAD driveline penetrates the skin along the body surface and is fixed near the penetration site (n = 224). In contrast, in our modified fixation method, the LVAD driveline vertically penetrates the skin to prevent ischemia at the driveline exit site and is fixed at a distant abdominal site to prevent the movement of the driveline exit site due to body movement (n = 38). The rates of freedom from LVAD driveline infection in patients with conventional driveline management were 86, 75, and 63% at 1, 2, and 3years after LVAD implantation, respectively. The rate of freedom from LVAD driveline infection in patients managed by the modified fixation method was 91% at 1, 2, as well as 3years after LVAD implantation. The freedom rates from LVAD driveline infection in the patients with modified fixation method was lower than in the patients with the conventional method (p = 0.04). Our study revealed that the modified fixation method may offer the possibility for preventing LVAD driveline infection.

Behavior of Fe-based alloys in a liquid lead-bismuth environment under simultaneous proton irradiation and corrosion

Behavior of Fe-based alloys in a liquid lead-bismuth environment under simultaneous proton irradiation and corrosion

Anatomical Ablation of the Atrioventricular Node.

Atrioventricular (AV) conduction ablation has been achieved by targeting the area of penetration of the conduction axis as defined by recording a His bundle potential. Ablation of the His bundle may reduce the possibility of a robust junctional escape rhythm. It was hypothesised that specific AV nodal ablation is feasible and safe. The anatomical position of the AV node in relation to the site of penetration of the conduction axis was identified as described in dissections and histological sections of human hearts. Radiofrequency (RF) ablation was accomplished based on the anatomical criteria. Specific anatomical ablation of the AV node was attempted in 72 patients. Successful AV nodal ablation was accomplished in 63 patients (87.5%), following 60 minutes (IQR 50-70 minutes) of procedure time, 3.4 minutes (IQR 2.4-5.5 minutes) of fluoroscopy time, and delivery of 4 (IQR 3-6) RF lesions. An escape rhythm was present in 45 patients (71%), and the QRS complex was similar to that before ablation in all 45 patients. Atropine was administered in six patients after the 10-min waiting period and did not result in restoration of conduction. In nine patients, AV conduction could not be interrupted, and AV block was achieved with ablation of the His after delivery of 12 (IQR 8-15) RF lesions. No cases of sudden death were encountered, and all patients had persistent AV block during a median 10.5 months (IQR 5-14 months) of follow-up. Anatomical ablation of the AV node is feasible and safe, and results in an escape rhythm similar to that before ablation.

Lignin accumulation in cell wall plays a role in clubroot resistance.

Clubroot, caused by Plasmodiophora brassicae, is a significant disease affecting brassica crops worldwide and poses a threat to canola (Brassica napus) production in western Canada. Management of this disease heavily relies on the use of resistant cultivars, but resistance erosion is a serious concern due to the highly diverse pathogen populations. Understanding resistance mechanisms may aid in better deployment/rotation of clubroot resistance (CR) genes and improve resistance resilience. In this study, we conducted a comparative analysis using resistant canola varieties carrying either a single (Rcr1) or double CR genes (Rcr1+Crr1rutb ) to decipher the resistance modes associated with these genes. Cell wall (CW) biopolymeric compounds in different root layers were mapped and quantified using Fourier-transform mid-infrared microspectroscopy for changes in CW elements associated with clubroot resistance. Transmission electron and confocal microscopy were used to assess root infection details and relative transcript abundance was analyzed to determine the activation of the lignin-related pathway in relation to resistance. Neither resistant variety affected the primary infection of root hairs/epidermal cells compared to the susceptible "Westar", but both exhibited strong inhibition of cortical infection, effectively 'trapping' the pathogen in the exodermis. The most prominent change observed was increased lignin accumulation associated with resistance. In Westar, the pathogen was able to degrade CW lignin, facilitating access to the root cortex by secondary plasmodia of P. brassicae. In contrast, resistant varieties showed clear lignin accumulation around the penetration site on the exodermis, accompanied by elevated expression of genes involved in the phenylpropanoid pathway. These results suggest that induced lignin accumulation plays a role in clubroot resistance mediated by the CR genes Rcr1 and Crr1rutb in canola, providing cellular and structural evidence that supports the data from earlier transcriptomic studies.

Preparation of polyethylene based composite nanofiltration membrane and its application in removal of heavy metals for water purification

Preparation of polyethylene based composite nanofiltration membrane and its application in removal of heavy metals for water purification

The cysteine-rich virulence factor NipA of Arthrobotrys flagrans interferes with cuticle integrity of Caenorhabditis elegans

Animals protect themself from microbial attacks by robust skins or a cuticle as in Caenorhabditis elegans. Nematode-trapping fungi, like Arthrobotrys flagrans, overcome the cuticle barrier and colonize the nematode body. While lytic enzymes are important for infection, small-secreted proteins (SSPs) without enzymatic activity, emerge as crucial virulence factors. Here, we characterized NipA (nematode induced protein) which A. flagrans secretes at the penetration site. In the absence of NipA, A. flagrans required more time to penetrate C. elegans. Heterologous expression of the fungal protein in the epidermis of C. elegans led to blister formation. NipA contains 13 cysteines, 12 of which are likely to form disulfide bridges, and the remaining cysteine was crucial for blister formation. We hypothesize that NipA interferes with cuticle integrity to facilitate fungal entry. Genome-wide expression analyses of C. elegans expressing NipA revealed mis-regulation of genes associated with extracellular matrix (ECM) maintenance and innate immunity.

Infection of Alfalfa Cotyledons by an Incompatible but Not a Compatible Species of Colletotrichum Induces Formation of Paramural Bodies and Secretion of EVs.

Hemibiotrophic fungi in the genus Colletotrichum employ a biotrophic phase to invade host epidermal cells followed by a necrotrophic phase to spread through neighboring mesophyll and epidermal cells. We used serial block face-scanning electron microscopy (SBF-SEM) to compare subcellular changes that occur in Medicago sativa (alfalfa) cotyledons during infection by Colletotrichum destructivum (compatible on M. sativa) and C. higginsianum (incompatible on M. sativa). Three-dimensional reconstruction of serial images revealed that alfalfa epidermal cells infected with C. destructivum undergo massive cytological changes during the first 60 h following inoculation to accommodate extensive intracellular hyphal growth. Conversely, inoculation with the incompatible species C. higginsianum resulted in no successful penetration events and frequent formation of papilla-like structures and cytoplasmic aggregates beneath attempted fungal penetration sites. Further analysis of the incompatible interaction using focused ion beam-scanning electron microscopy (FIB-SEM) revealed the formation of large multivesicular body-like structures that appeared spherical and were not visible in compatible interactions. These structures often fused with the host plasma membrane, giving rise to paramural bodies that appeared to be releasing extracellular vesicles (EVs). Isolation of EVs from the apoplastic space of alfalfa leaves at 60 h postinoculation showed significantly more vesicles secreted from alfalfa infected with incompatible fungus compared with compatible fungus, which in turn was more than produced by noninfected plants. Thus, the increased frequency of paramural bodies during incompatible interactions correlated with an increase in EV quantity in apoplastic wash fluids. Together, these results suggest that EVs and paramural bodies contribute to immunity during pathogen attack in alfalfa. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

An incremental energy stimulation test to predict success in left bundle branch capture

Abstract Introduction Left bundle branch (LBB) stimulation is guided by fluoroscopic projections and electrocardiographic criteria limited by positional variations. Purpose To evaluate an incremental energy stimulation test (IEST) to optimize success. Methods Prospective, non-randomized experimental study for proof-of-concept analysis (N=23), consisting on: (i) stimulation at three locations at the high, middle and low right mid-ventricular septum (right oblique 30o); and (ii) continuous unipolar stimulation (lumenless fixed helix electrode) at each location with increasing outputs (2 volt x 0.5 ms up to 10 vol x 1.5 ms). The final position for lead penetration was made by the operator blinded to the results of the IEST. Results IEST shortened the S-LVAT (δ-S-LVAT) up to 6.4±5 ms (range 0 to 18 ms), 8±8 ms (range 0 to 36 ms) and 5.5±5 ms (range 0 to 20 ms) respectively for high, mid, and low sites (Figure, panel A and B). There was not observed any paired correlation between the magnitude of the δ-S-LVAT at the three different positions (Pearson 0.36, 0.12 and 0.22; p= 0.1, 0.6 and 0.4 respectively), suggesting that the δ-S-LVAT is site specific. The final position for lead penetration was medium in 17 cases vs low in 6 cases. The low-output S-LVAT interval at the final position before lead penetration was positively correlated with the final S-LVAT achieved after lead penetration (Pearson 0.44; p=0.04), but the magnitude of the correlation increased with the high-output S-LVAT interval (Pearson 0.57; p=0.006) suggesting a better prediction performance (Figure, panel C). A complex relationship was observed where higher δ-S-LVAT values were associated with shorter S-LVAT after penetration and final position of the lead. In fact, for cases with low-output S-LVAT interval > 100 ms, the δ-S-LVAT significantly correlated with S-LVAT after penetration and final position of the lead (Pearson -0.61; p=0.026). Conclusions IEST lead to a site-specific shortening of the S-LVAT, pointing to optimized positions for LBB pacing. The technique provides with additional diagnostic criteria to determine the better site for lead penetration.

Sodium Tetraborate Induces Systemic Resistance in Watermelon against Stagonosporopsis cucurbitacearum

Imbibing watermelon seeds in 1 mM sodium tetraborate (Na2B4O7) for 24 h systemically protected plants against foliar infection by Stagonosporopsis cucurbitacearum in detached leaves and under greenhouse conditions. The treatment resulted in both a reduction in the overall percentage of leaf infection as well as in the size of lesions. Studies of the mechanisms by which Na2B4O7 protected watermelon showed that there was no direct effect on the S. cucurbitacearum mycelium growth in vitro. On the other hand, plants raised from seeds primed with Na2B4O7 showed a higher frequency of fluorescent epidermal cells compared to the plants treated with water. This indicates that a higher number of cells expressed the hypersensitive response after Na2B4O7 priming. In addition, there was an increase in peroxidase activity and an enhanced accumulation of a 45 kDa acidic peroxidase isoform during the early stages of infection in plants treated with Na2B4O7 compared to plants treated with water and this was positively correlated to the reduction of leaf infection caused by the pathogen. These results indicate that Na2B4O7 is able to induce systemic resistance in watermelon against S. cucurbitacearum by activating the hypersensitive reaction at penetration sites, increasing peroxidase activity and altering the peroxidase isozyme profile. Although each individual response may only have had a minor effect, their combined effects had a reducing effect on the disease.

Infection Biology of Stagonosporopsis cucurbitacearum in Watermelon and Defence Responses in the Host

Infection biology and defence responses of watermelon attacked by Stagonosporopsis cucurbitacearum (syn. Didymella bryoniae) were studied in two genotypes, accessions PI189225 (moderately resistant) and 232-0125/B (susceptible). On intact leaf surfaces, spores started to germinate 14 h after inoculation (hai) with one to three germ tubes, which subsequently developed and formed appressoria. Invasion of the host tissue started at 20 hai by direct penetration from appressoria or occasionally indirectly through stomata. In the susceptible accession, a significantly higher number of direct penetrations were observed than in the moderately resistant. After invasion, hyphal colonisation was restricted in the intercellular spaces in the moderately resistant accession, whereas they developed extensively, causing tissue decay, in the susceptible accession. Macroscopic symptoms were seen in leaves of the moderately resistant accession as small and dry lesions, whereas big, water-soaked lesions developed on the susceptible accession within 48 hai. Investigations of the defence responses of the two accessions showed accumulation of H2O2 at penetration sites beneath appressoria in the moderately resistant, but to a lesser extent in the susceptible accession. Such H2O2 accumulation correlated with a reduction in penetration frequency and a lower level of hyphal growth after infection in the moderately resistant accession. There was a rapid and early increase in total peroxidase as well as β-1,3-glucanase activity in the moderately resistant compared to the susceptible accession. These results indicate that fungal penetration and development in watermelon are inhibited by a consorted action of different responses including accumulation of H2O2, peroxidase and β-1,3-glucanase.

Fast, Easy, and Comprehensive Techniques for Microscopic Observations of Fungal and Oomycete Organisms Inside the Roots of Herbaceous and Woody Plants.

The roots of herbaceous and woody plants growing in soil are complex structures that are affected by both natural and artificial fungal colonization to various extents. To obtain comprehensive information about the overall distribution of fungi or oomycetes inside a plant root system, rapid, effective, and reliable screening methods are required. To observe both fine roots, i.e., a common site for penetration of fungi and oomycetes, and mature roots, different techniques are required to overcome visual barriers, such as root browning or tissue thickening. In our protocol, we propose using fast, cost-effective, and non-harmful methods to localize fungal or oomycete structures inside plant roots. Root staining with a fluorescent dye provides a quick initial indication of the presence of fungal structures on the root surfaces. The protocol is followed by clearing and staining steps, resulting in a deeper insight into the root tissue positioning, abundance, and characteristic morphological/reproductive features of fungal or oomycete organisms. If required, the stained samples can be prepared by using freeze-drying for further observations, including advanced microscopic techniques. Key features • The protocol enhances tissue-clearing techniques employing KOH or NaOH and is applicable to a broad range of roots from different plant species. • Hydroxides are mixed with hydrogen peroxide to obtain an efficient bleaching solution, which effectively clears roots without causing significant tissue damage. • The protocol could also be used for staining of fungi or oomycetes localized both on the root surface or inside the root tissues. • Simple combination of non-fluorescent methyl blue and fluorescent solophenyl flavine dyes allows the observation of fungal organisms in both brightfield and fluorescence microscopy.

Structural analysis of the mylohyoid muscle as a septum dividing the floor of the oral cavity for the purposes of dental implant surgery: variety of muscle attachment positions and ranges of distribution

ObjectivesThe objective was to investigate the details of the attachments of the mylohyoid muscle to the mandible anterior to the hyoid and mylohyoid lines to understand the positional relationship between the sublingual space and the mylohyoid, knowledge that is essential for dental implant surgery in the incisal region, as well as the routes of communication between the sublingual space and other spaces.MethodsWhile evaluating the presence or absence of an anterior mylohyoid muscle fiber attachment to the mandible, sublingual gland herniation, spaces between muscle fascicles were also recorded as sites of penetration. The mean muscle thickness in each of these areas was also calculated.ResultsIn all specimens, the mylohyoid originated not only from the mylohyoid line but also from the lingual surface of the center of the mandibular body (the mandibular symphysis) below the mental spines. The mylohyoid muscle fascicles were thickest in the posterior region, and further anterior to this, they tended to become thinner. Sublingual gland herniations passing through the mylohyoid were noted in the anterior and central regions, but not in the posterior region. Penetration between the muscle fascicles was most common in the central region, and no such penetration was evident in the posterior region.ConclusionsThese results suggest that the mylohyoid functions only incompletely as a septum, and that routes of communication from the sublingual space to the submandibular space may be present in both the anterior and central muscle fascicles of the mylohyoid. Therefore, bleeding complications during dental implant placement in the anterior mandible can be serious issues. There is a potential for sublingual hematoma that could compromise the airway by pressing the tongue against the soft palate into the pharynx.

A GH81-type β-glucan-binding protein enhances colonization by mutualistic fungi in barley

A GH81-type β-glucan-binding protein enhances colonization by mutualistic fungi in barley

High-performance flexible energy storage: Decorating wrinkled MXene with in situ grown Cu2O nanoparticles

High-performance flexible energy storage: Decorating wrinkled MXene with in situ grown Cu2O nanoparticles