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MBio Apr 2024Intracellular infectious agents, like the malaria parasite, , face the daunting challenge of how to invade a host cell. This problem may be even harder when the host...
UNLABELLED
Intracellular infectious agents, like the malaria parasite, , face the daunting challenge of how to invade a host cell. This problem may be even harder when the host cell in question is the enucleated red blood cell, which lacks the host machinery co-opted by many pathogens for internalization. Evolution has provided and related single-celled parasites within the phylum Apicomplexa with a collection of organelles at their apical end that mediate invasion. This apical complex includes at least two sets of secretory organelles, micronemes and rhoptries, and several structural features like apical rings and a putative pore through which proteins may be introduced into the host cell during invasion. We perform cryogenic electron tomography (cryo-ET) equipped with Volta Phase Plate on isolated and vitrified merozoites to visualize the apical machinery. Through tomographic reconstruction of cellular compartments, we see new details of known structures like the rhoptry tip interacting directly with a rosette resembling the recently described rhoptry secretory apparatus (RSA) or with an apical vesicle docked beneath the RSA. Subtomogram averaging reveals that the apical rings have a fixed number of repeating units, each of which is similar in overall size and shape to the units in the apical rings of tachyzoites of . Comparison of these polar rings in and parasites also reveals them to have a structurally conserved assembly pattern. These results provide new insight into the essential and structurally conserved features of this remarkable machinery used by apicomplexan parasites to invade their respective host cells.
IMPORTANCE
Malaria is an infectious disease caused by parasites of the genus and is a leading cause of morbidity and mortality globally. Upon infection, parasites invade and replicate in red blood cells, where they are largely protected from the immune system. To enter host cells, the parasites employ a specialized apparatus at their anterior end. In this study, advanced imaging techniques like cryogenic electron tomography (cryo-ET) and Volta Phase Plate enable unprecedented visualization of whole merozoites, revealing previously unknown structural details of their invasion machinery. Key findings include new insights into the structural conservation of apical rings shared between and its apicomplexan cousin, . These discoveries shed light on the essential and conserved elements of the invasion machinery used by these pathogens. Moreover, the research provides a foundation for understanding the molecular mechanisms underlying parasite-host interactions, potentially informing strategies for combating diseases caused by apicomplexan parasites.
Topics: Animals; Plasmodium falciparum; Electron Microscope Tomography; Protozoan Proteins; Parasites; Plasmodium; Host-Parasite Interactions; Malaria; Toxoplasma
PubMed: 38456679
DOI: 10.1128/mbio.02864-23 -
Spine Deformity Sep 2023The current study aims to evaluate the effect of Boston brace treatment on apical vertebral derotation in adolescent idiopathic scoliosis (AIS) patients receiving...
PURPOSE
The current study aims to evaluate the effect of Boston brace treatment on apical vertebral derotation in adolescent idiopathic scoliosis (AIS) patients receiving conservative treatment.
METHODS
The study included 51 AIS patients, consisting of 8 males and 43 females, with Cobb angles between 25° and 45° and Risser's findings ranging from 0 to 4. The mean age of the participants was 12.20 ± 1.34 years. All patients were treated with the Boston brace for a minimum of 2 years and evaluated before the brace, during early brace use, and at the last follow-up. Radiographs were assessed to measure apical vertebral rotation (AVR) and vertebral translation (AVT). The SRS-22 questionnaire was used to evaluate patient outcomes.
RESULTS
The radiographs of patients were evaluated over a mean follow-up period of 32.42 ± 8.65 months. Before the brace, the mean AVR was 2.1 ± 0.6, while it was 1.1 ± 0.5 with the brace. At the last follow-up, the mean AVR was 1.3 ± 0.5 (p < 0.001). Before the brace, the mean AVT was 36.4 ± 9.6 mm, which decreased to 16.7 ± 7.3 mm with the brace (p < 0.001). At the last follow-up, the mean AVT was 19.8 ± 8.1 mm (p < 0.001). The use of the brace had a significant corrective effect on thoracolumbar and lumbar curvatures compared to before the brace (p < 0.001).
CONCLUSION
The findings of the current study suggest that the use of a Boston brace in the conservative treatment of AIS is effective in correcting the coronal and sagittal plane deformities, including thoracic, thoracolumbar, and lumbar curvatures, and in reducing apical vertebral rotation and translation.
Topics: Female; Male; Humans; Adolescent; Child; Scoliosis; Spine; Kyphosis; Braces; Orthotic Devices
PubMed: 37221316
DOI: 10.1007/s43390-023-00703-z -
Journal of Nuclear Cardiology :... Oct 2023
Topics: Humans; Apical Hypertrophic Cardiomyopathy; Cardiomyopathy, Hypertrophic; Heart Transplantation; Electrocardiography
PubMed: 36575283
DOI: 10.1007/s12350-022-03167-2 -
Journal of Clinical and Experimental... Nov 2023The success of endodontic treatment can be influenced by the type of endodontic sealer used, as certain sealers may be prone to apical microleakage, leading to treatment...
BACKGROUND
The success of endodontic treatment can be influenced by the type of endodontic sealer used, as certain sealers may be prone to apical microleakage, leading to treatment failure. The limitations of currently available sealers necessitate the development of new materials to improve the success rate of endodontic treatment. Therefore, the objective of this study was to assess the apical microleakage of newly developed hydroxyapatite-based endodontic sealers, including one derived from eggshells, and compare them with other commercially available sealers.
MATERIAL AND METHODS
Eighty-five extracted human upper anterior teeth were selected for this study. The teeth were divided into 5 experimental groups and 2 control groups. The experimental groups were designated as follows: (1) HPSINT - obturated with gutta-percha cone and synthetic hydroxyapatite-based sealer, (2) BIOC - obturated with gutta-percha cone and Bio C-Sealer sealer, (3) AHPLUS-BC - obturated with gutta-percha cone and AHPLUS Bioceramic sealer, (4) AHP - obturated with gutta-percha cone and AHPLUS sealer, and (5) HPO - obturated with gutta-percha cone and sealer based on hydroxyapatite extracted from eggshells. Additionally, there were positive and negative control groups consisting of instrumented teeth filled with gutta-percha cones without any sealer and instrumented teeth without any filling, respectively. Methylene blue dye penetration was used to assess apical microleakage. Descriptive statistical analysis and Shapiro-Wilk normality test were applied to the observed results. As the samples followed a normal distribution, the ANOVA test was applied.
RESULTS
The control groups confirmed the validity of the experimental method, while the experimental groups showed varying degrees of dye penetration. The group obturated with Bio C-Sealer exhibited the highest mean apical microleakage, while AHPLUS Bioceramic sealer demonstrated lower mean than AHPLUS sealer and sealer based on hydroxyapatite extracted from eggshells (<0.05). Finally, there was no difference between the synthetic hydroxyapatite-based sealer and AHPLUS Bioceramic sealer, AHPLUS sealer and sealer based on hydroxyapatite extracted from eggshells (>0.05). No significant difference was observed between the hydroxyapatite-based sealers and the AHPLUS-BC sealer.
CONCLUSIONS
The results of this study suggest that the newly developed hydroxyapatite-based endodontic sealers, including the one derived from eggshells, may have a lower risk of apical microleakage compared to other commercially available sealers. These findings highlight the potential of hydroxyapatite-based sealers to improve the success rate of endodontic treatment. Further research and clinical studies are warranted to validate these results and explore the long-term effects of these novel sealers. Endodontic treatment, apical microleakage, endodontic sealer, hydroxyapatite, eggshell-derived sealer.
PubMed: 38074171
DOI: 10.4317/jced.60743 -
Effects of Rheumatoid Arthritis on the Progression of Pulpitis and Apical Periodontitis in SKG Mice.Journal of Endodontics Nov 2023Rheumatoid arthritis (RA) is an autoimmune disease that involves joint inflammation. Although periodontal disease reportedly contributes to RA onset, the associations of...
INTRODUCTION
Rheumatoid arthritis (RA) is an autoimmune disease that involves joint inflammation. Although periodontal disease reportedly contributes to RA onset, the associations of RA with pulpitis and apical periodontitis have not been described. The purpose of this study was to examine the effects of immune response disruption of RA for pulpitis and apical periodontitis with SKG mice.
METHODS
SKG and BALB/c (control) mice were used to establish models of pulp infection. Histologic studies of pulp and apical periodontal tissue were performed at 3, 5, 7, 14, and 28 days; odontoblast dynamics were analyzed by antinestin staining, and apoptotic cells were examined by TdT-mediated digoxygenin (biotin)-dUTP nick end labeling staining.
RESULTS
Inflammatory cell infiltration into the exposed pulp was observed at 3 days in the SKG and control group groups; the infiltration extended to the apical pulp area at 14 days after surgery. Inflammatory cell infiltration and bone resorption in the apical pulp area were observed from 14-28 days in the SKG and control groups; there were significant increases in inflammatory cell infiltration and bone resorption in the control group at 28 days. The numbers of apoptotic cells in pulp and apical periodontal tissue were higher in the SKG group than in the control group at 14 and 28 days. The number of odontoblasts decreased in the SKG and control groups until 14 days and then disappeared in the SKG and control groups at 28 days.
CONCLUSIONS
This study suggested that immune response disruption in RA is involved in prolonging the inflammatory state of pulpitis and apical periodontitis.
Topics: Animals; Periapical Periodontitis; Pulpitis; Arthritis, Rheumatoid; Mice; Mice, Inbred BALB C; Disease Progression; Disease Models, Animal; Apoptosis; Odontoblasts; Dental Pulp; Male
PubMed: 37595682
DOI: 10.1016/j.joen.2023.08.003 -
Ultrasound in Medicine & Biology Sep 2023Automated detection of foreshortening, a common challenge in routine 2-D echocardiography, has the potential to improve quality of acquisitions and reduce the...
OBJECTIVE
Automated detection of foreshortening, a common challenge in routine 2-D echocardiography, has the potential to improve quality of acquisitions and reduce the variability of left ventricular measurements. Acquiring and labelling the required training data is challenging due to the time-intensive and highly subjective nature of foreshortened apical views. We aimed to develop an automatic pipeline for the detection of foreshortening. To this end, we propose a method to generate synthetic apical-four-chamber (A4C) views with matching ground truth foreshortening labels.
METHODS
A statistical shape model of the four chambers of the heart was used to synthesise idealised A4C views with varying degrees of foreshortening. Contours of the left ventricular endocardium were segmented in the images, and a partial least squares (PLS) model was trained to learn the morphological traits of foreshortening. The predictive capability of the learned synthetic features was evaluated on an independent set of manually labelled and automatically curated real echocardiographic A4C images.
RESULTS
Acceptable classification accuracy for identification of foreshortened views in the testing set was achieved using logistic regression based on 11 PLS shape modes, with a sensitivity, specificity and area under the receiver operating characteristic curve of 0.84, 0.82 and 0.84, respectively. Both synthetic and real cohorts showed interpretable traits of foreshortening within the first two PLS shape modes, reflected as a shortening in the long-axis length and apical rounding.
CONCLUSION
A contour shape model trained only on synthesized A4C views allowed accurate prediction of foreshortening in real echocardiographic images.
Topics: Echocardiography; Heart; Heart Ventricles; Endocardium; Models, Statistical
PubMed: 37328385
DOI: 10.1016/j.ultrasmedbio.2023.05.003 -
The Journal of Obstetrics and... Jun 2024Laparoscopic lateral suspension is a novel approach for repairing anterior and apical pelvic organ prolapse (POP). According to integral theory, urinary symptoms and...
AIM
Laparoscopic lateral suspension is a novel approach for repairing anterior and apical pelvic organ prolapse (POP). According to integral theory, urinary symptoms and pelvic pain are believed to originate from suspensory ligaments. We aimed to investigate the objective and subjective outcomes of adding sacroterine plication to apical prolapse surgery.
METHODS
Sixty patients with Grade 2 or higher symptomatic apical POP were included in the study. The study sample was categorized into two groups: Group 1 underwent lateral suspension and Group 2 underwent lateral suspension and sacroterine plication. Anatomical cure was defined separately for the apical and anterior compartments as POP-Q scores for sites C and Ba of less than -1 cm for each compartment. A subjective cure was defined as the absence of bulge symptoms. Patient satisfaction, sexual function, prolapse-related quality of life, voiding dysfunction, nocturia, and constipation were assessed.
RESULTS
In Group 1, anatomical cure rates for apical and anterior prolapse were 100% and 70%, respectively (p <0.001). In Group 2, these rates were 100% for apical prolapse and 73.3% for anterior prolapse (p <0.001). The subjective cure was 96.6% in both groups. Furthermore, improvement in sexual and urinary symptoms was more significant in the group that underwent sacroterine plication (p <0.001).
CONCLUSIONS
The additional sacroterine plication (shortening) procedure with lateral suspension proved to be an effective and successful surgical approach for apical prolapse. Its routine addition to existing lateral suspension surgery can contribute significantly to the improvement of urinary and prolapse symptoms.
Topics: Humans; Female; Middle Aged; Pelvic Organ Prolapse; Prospective Studies; Aged; Gynecologic Surgical Procedures; Laparoscopy; Adult; Treatment Outcome; Patient Satisfaction
PubMed: 38627198
DOI: 10.1111/jog.15941 -
Australian Endodontic Journal : the... Sep 2023This study evaluated the accuracy of the Wirele-X (Forum Tec, Ashkelon, Israel), a novel Bluetooth-enabled wireless electronic apex locator. Thirty-one extracted teeth...
This study evaluated the accuracy of the Wirele-X (Forum Tec, Ashkelon, Israel), a novel Bluetooth-enabled wireless electronic apex locator. Thirty-one extracted teeth with mature apices were used. Under 10X magnification, the actual canal lengths were determined. The teeth were embedded in alginate and electronic canal lengths were obtained using the Root ZX II and Wirele-X electronic apex locators. The actual canal lengths and electronic canal lengths were compared with Student's t-test. The average distance from the file tip to the actual canal length was -0.11 mm (±0.16) for the Root ZX II, and - 0.07 mm (±0.21) for the Wirele-X. There were no statistically significant differences between the two electronic apex locators in their ability to determine the actual canal length (p > 0.05). The wireless apex locator (Wirele-X) and the wired apex locator (Root ZX II) were found to be equally accurate.
Topics: Humans; Tooth Apex; Dental Pulp Cavity; Odontometry; Tooth Root; Electronics; Root Canal Preparation
PubMed: 36106697
DOI: 10.1111/aej.12688 -
Cells Aug 2023Club Cell Secretory Protein (CC16) plays many protective roles within the lung; however, the complete biological functions, especially regarding the pulmonary epithelium...
Club Cell Secretory Protein (CC16) plays many protective roles within the lung; however, the complete biological functions, especially regarding the pulmonary epithelium during infection, remain undefined. We have previously shown that CC16-deficient (CC16) mouse tracheal epithelial cells (MTECs) have enhanced Mp burden compared to CC16-sufficient (WT) MTECs; therefore, in this study, we wanted to further define how the pulmonary epithelium responds to infection in the context of CC16 deficiency. Using mass spectrometry and quantitative proteomics to analyze proteins secreted apically from MTECs grown at an air-liquid interface, we investigated the protective effects that CC16 elicits within the pulmonary epithelium during (Mp) infection. When challenged with Mp, WT MTECs have an overall reduction in apical protein secretion, whereas CC16 MTECs have increased apical protein secretion compared to their unchallenged controls. Following Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) assessment, many of the proteins upregulated from CC16 MTECS (unchallenged and during Mp infection) were related to airway remodeling, which were not observed by WT MTECs. These findings suggest that CC16 may be important in providing protection within the pulmonary epithelium during respiratory infection with Mp, which is the major causative agent of community-acquired pneumoniae.
Topics: Animals; Mice; Epithelial Cells; Epithelium; Lung; Pneumonia, Mycoplasma; Proteins; Uteroglobin; Mice, Knockout
PubMed: 37566063
DOI: 10.3390/cells12151984 -
Protoplasma Jan 2024Colleters are secretory structures characteristic of the apices of more than 60 botanical families. In the Myrtaceae, three types of colleters were previously described:...
Colleters are secretory structures characteristic of the apices of more than 60 botanical families. In the Myrtaceae, three types of colleters were previously described: petaloid, conical, and euriform. In Argentina, most species of the Myrtaceae family grow in subtropical regions and a few in the temperate-cold zones of Patagonia. We evaluated the vegetative buds of five species of the subfamily Myrtoideae, tribe Myrtea: Amomyrtus luma, Luma apiculata, and Myrceugenia exsucca, native to the temperate rainforests of Patagonia and Myrcianthes pungens and Eugenia moraviana from the riparian forest of northwestern Corrientes, in order to analyze the presence and morphological types and main secretion products of colleters. Optical and scanning electron microscopy was used to identify the presence of colleters in vegetative organs. Histochemical tests were performed to identify the main secretion products in these structures. The colleters are on the inner side of the leaf primordia and cataphylls and on the edge of the petiole, where they replace the stipules. They are classified as homogeneous because they consist of epidermis and internal parenchyma, both formed by cells with similar characteristics. They lack vascularization and originate from the protodermis. The colleters are of the conical type in L. apiculata, M. pungens, and E. moraviana and of the euriform type in A. luma and M. exsucca, the latter being identified by its dorsiventrally flattened shape. Histochemical tests showed the presence of lipids, mucilage, phenolic compounds, and proteins. This is the first time that colleters have been described in the analyzed species; the taxonomical and phylogenetic importance of this structures is discussed in relation to the Myrtaceae family.
Topics: Humans; Myrtaceae; Phylogeny; Microscopy, Electron, Scanning; Plant Leaves; Polysaccharides
PubMed: 37418157
DOI: 10.1007/s00709-023-01876-0