Ghost Cells Research Articles

A high-order immersed boundary method with ghost cells and flux reconstruction for inviscid flows

We propose a high-order immersed boundary (IB) method for simulating inviscid flows using the flux reconstruction (FR) method, which offers the advantages of a compact stencil, high-order near-wall accuracy, and the ability to handle thin geometries and sharp corners. We utilize the FR method on a Cartesian grid to achieve a compact stencil, which enhances accuracy without requiring surrounding cell information, laying the foundation for future adaptive mesh refinement. Compared to the symmetry wall condition treatment, we combine the curvature corrected symmetry technique with the FR-based IB method to achieve a high-order accuracy near the wall boundary and utilize a third-order polynomial distribution to impose the boundary conditions. We extend the multi-valued ghost-cell method to the present approach to handle thin geometries and sharp corners in the ghost-cell-based IB method. The proposed method can be easily extended to three-dimensional cases. The numerical framework is validated through several two-dimensional simulations of inviscid flows. The approach is first demonstrated for a superposition of an isentropic vortex and a background flow problem with a Mach number of 0.2, which examines the order of accuracy without wall effects in the grid convergence study. Then, inviscid flow around a cylinder and flow through a channel with a bump are tested and compared to body-fitted simulations. Finally, flows around a National Advisory Committee for Aeronautics 0012 airfoil with zero and non-zero angles of attack are demonstrated to show the robustness for the thin geometry calculation. In particular, third-order accuracy is maintained in the near-wall region.

Observer reliability in counting erythrocyte ghost cells and impact of short-term storage of canine and feline blood samples.

The presence of erythrocyte ghost cells (EG) in blood smears indicates intravascular haemolysis or in-vitro haemolysis. However, observer reliability in detection of EG has not been documented. Immediate blood smear preparation is advised but may not always be practical. This study investigated the reliability of EG detection and the impact of delayed blood smear preparation. Forty blood smears from dogs and cats were evaluated twice by four observers. EG development was studied in 59 dogs and nine cats, with smears prepared at 0, 2, and 24 h post-collection. Intra- and inter-observer reliability, as assessed using Krippendorff's Alpha, ranged from 0.567 and 0.949, and 0.522 and 0.848, respectively, indicating moderate to substantial agreement. No significant increase in EG occurrence was noted between 0 and 2 h, but a significant increase was observed at 24 h. The findings suggest that EG can be reliably detected and that blood smears for the evaluation of EG can be prepared up to 2 h after blood collection without compromising detection of EG.

Comparative evaluation of calretinin immunohistochemical expression in calcifying odontogenic cyst and ameloblastoma

BackgroundCalretinin is a 29 kilodalton (KDa) calcium-binding protein that is expressed in normal and tumoral tissues. The expression of calretinin has been shown in the dental epithelium during odontogenesis and in different odontogenic cysts and tumors such as ameloblastoma. Since the epithelium of calcifying odontogenic cyst (COC) is similar to ameloblastoma and in both lesions, an arrangement of loose cells similar to stellate reticulum is seen, we aimed to investigate the comparative expression of calretinin in COC and ameloblastoma.MethodsIn this observational-analytical study, 11 paraffin blocks of each lesion were examined. The immunohistochemical expression of calretinin and its severity and distribution were evaluated. Data were evaluated using SPSS version 26 and P < 0.05 was considered the level of significance.ResultsOut of 11 ameloblastoma samples, calretinin staining was positive in 6 samples in the stellate reticulum-like cells and also in the lining of microcysts and macrocysts in some cases. Ameloblast like cells did not show staining. In COC samples, epithelial cells were not stained, but in 8 samples, staining was seen in the area of ghost cells. There was no significant difference in staining between ameloblastoma and COC (P = 0.33), but the difference in staining in the stellate reticulum of ameloblastoma and COC was significant. (P = 0.012).Conclusionsit is concluded that calretinin does not play a role in the pathogenesis and histogenesis of COC epithelium, but since ghost cells are caused by a degenerative process, the possibility of involving calretinin as an apoptotic factor in the formation of these cells is supported.

Numerical Study on Hydrodynamic Performance and Vortex Dynamics of Multiple Cylinders Under Forced Vibration at Low Reynolds Number

Flow around clustered cylinders is widely encountered in engineering applications such as wind energy systems, pipeline transport, and marine engineering. To investigate the hydrodynamic performance and vortex dynamics of multiple cylinders under forced vibration at low Reynolds numbers, with a focus on understanding the interference characteristics in various configurations, this study is based on a self-developed radial basis function iso-surface ghost cell computing platform, which improves the implicit iso-surface interface representation method to track the moving boundaries of multiple cylinders, and employs a self-constructed CPU/GPU heterogeneous parallel acceleration technique for efficient numerical simulations. This study systematically investigates the interference characteristics of multiple cylinder configurations across various parameter domains, including spacing ratios, geometric arrangements, and oscillation modes. A quantitative analysis of key parameters, such as aerodynamic coefficients, dimensionless frequency characteristics, and vorticity field evolution, is performed. This study reveals that, for a dual-cylinder system, there exists a critical gap ratio between X/D = 2.5 and 3, which leads to an increase in the lift and drag coefficients of both cylinders, a reduction in the vortex shedding periodicity, and a disruption of the wake structure. For a three-cylinder system, the lift and drag coefficients of the two upstream cylinders decrease with increasing spacing. On the other hand, this increased spacing results in a rise in the drag of the downstream cylinder. In the case of a four-cylinder system, the drag coefficients of the cylinders located on either side of the flow direction are relatively high. A significant increase in the lift coefficient occurs when the spacing ratio is less than 2.0, while the drag coefficient of the downstream cylinder is minimized. The findings establish a comprehensive theoretical framework for the optimal configuration design and structural optimization of multicylinder systems, while also providing practical guidelines for engineering applications.

Preservation of cellular structure via immersion fixation in brain banking.

Immersing the brain in a solution containing formaldehyde is a commonly used method for preserving the structure of human brain tissue in brain banking. However, there are questions about the quality of preservation using this method, as formaldehyde takes a relatively long period of time to penetrate a large organ such as the human brain. As a result, there is a critical need to determine whether immersion fixation is an adequate initial preservation method. To address this, we present exploratory histologic findings from our brain bank following the immersion fixation of hemi-sectioned brain specimens under refrigeration. Using light microscopy, we found that there was no significant change in the size of pericellular or perivascular rarefaction areas based on the postmortem interval (PMI) or on the progression from the outer (frontal cortex) to the inner (striatum) brain regions. Additionally, we did not identify any significant number of ghost cells - a state of late-stage cellular necrosis - in the light micrographs analyzed. Using transmission electron microscopy of tissue from the frontal cortex, we found that synapses could still be visualized, but there was vacuolization and variable degrees of myelin disbanding identified. Using serial section transmission electron microscopy, we found that identified synapses could be traced from one section to the next. Using serial block face scanning electron microscopy, we also found that myelinated axons on 2D images can be traced with high fidelity from one image to the next, even at PMIs of up to 27 hours. Collectively, our data corroborate previous findings that immersion fixation is effective for prevention of cellular necrosis and for visualizing many ultrastructural features in at least the surface areas of the brain. However, how structural preservation quality should best be assessed in brain banking is an open question that depends on the intended research applications.

Malignant Pilomatricoma with Lung Metastases: A Case Report and Literature Review.

Malignant pilomatricoma, an extremely rare tumor arising from hair follicles, most commonly occurs on the head, neck, and back. This tumor exhibits several noteworthy characteristics. First, it frequently recurs if it is incompletely excised and can occasionally metastasize to the lungs, bones, and lymph nodes. Additionally, it possesses unique histological features that aid in differentiating it from its benign counterpart, including atypical cells, multiple mitoses with ghost cells, nuclear polymorphisms, and necrosis accompanied by serial desmoplasia. While no definitive criteria have been established for the surgical management of this malignant tumor, it is recommended to perform wide local excision with a safety margin of at least ≥5 mm. To the best of our knowledge, very few cases of malignant pilomatricoma with lung metastasis have been reported in Korea. Here we report the case of a patient diagnosed of malignant pilomatricoma with lung metastasis who underwent wide local excision for a lesion on the flank.

Successful treatment of mandibular central dentinogenic ghost cell tumor with en bloc resection and dental rehabilitation: A case report

Successful treatment of mandibular central dentinogenic ghost cell tumor with en bloc resection and dental rehabilitation: A case report

Bone Tumors of the Jaw - the "Blind Spot" for Radiologists Experienced with Tumors? - Part II.

Primary bone tumours of the jaw are rare tumoral entities and do substantially differ from other bone tumours of the human body with respect of their frequently encountered unusual radiological appearances. The reason for that may be confined to the co-existence of two closely neighbored but different anatomical structures (i.e., tooth-forming apparatus and jaw bones with adjacent gingiva) and some tumour pathologies which are nearly excusively encountered in the jaw bones only (e.g., ameloblastoma, ossifying fibroma, ghost cell carcinoma).This paper would like to highlight some basic principles of the diagnostic approach and possibilities of radiological differentiation of such tumour-suspicious changes within the gnathic system are elucidated and discussed.The paper presented here is substantially based on the most recent classification of odontogenic and maxillofacial tumours (5th edition, 2022) which serves as a scaffold for the selection of typical tumour entities. Due to the educational character of this paper, only important jaw tumours worth mentioning and their characteristics are subject to be extracted from the literature and further discussed.The main focus was put onto both the description of radiological tumoral appearance and the rational selection of a radiological diagnostic work-up. In order to better visualize this difficult field of tumour entities, much attention has been paid on a comprehensive pictorial essay.For radiologists, it is their foremast task to detect, describe, and to classify bone tumours of the jaw when they are found intentionally or accidentally, resp. A close co-operation with their clinical partners is of upmost importance to gain information about patient´s history and clinical presentation. It is readily reasonable that radiologists are mostly able to provide only a suggestion of the presented tumour entity but this expert opinion would be very helpful to further narrow down the list of potential differential diagnoses (e.g., differentiation of a cyst vs. solid tumour osteolysis, identification of jaw osteomyelitis vs. tumoral infiltration, recognizing of secondary tumour involvement of the jaw). · primary bone tumours of the jaw are very rare, moreover difficult to differentiate radiologically, and do need therefore histological proof;. · profound knowledge about tumour characteristics (location within the jaw, relationship to the tooth, bony destructive pattern) may allow a rough orientation and classification;. · matrix-forming tumours and dysplasias of the jaw facilitates their radiological differentiation and classification;. · in contrary, osteolyses should be thoroughly scrutinized for the more frequent gnathic cysts in differentiation of rather rare solid primary tumours;. · an interdisciplinary round-table discussion amongst well-experienced maxillofacial surgeons and specialized radiologists may be appropriate to avoid severe misinterpretations.. · Grieser T, Hirsch E, Tödtmann N. Tumours of the jaw bones - Part II. Fortschr Röntgenstr 2024; DOI 10.1055/a-2416-1282.

Bone Tumors of the Jaw - the "Blind Spot" for Radiologists Experienced with Tumors? - Part I.

Primary bone tumours of the jaw are rare tumoral entities and do substantially differ from other bone tumours of the human body with respect of their frequently encountered unusual radiological appearances. The reason for that may be confined to the co-existence of two closely neighbored but different anatomical structures (i.e., tooth-forming apparatus and jaw bones with adjacent gingiva) and some tumour pathologies which are nearly excusively encountered in the jaw bones only (e.g., ameloblastoma, ossifying fibroma, ghost cell carcinoma).This paper would like to highlight some basic principles of the diagnostic approach and possibilities of radiological differentiation of such tumour-suspicious changes within the gnathic system are elucidated and discussed.The paper presented here is substantially based on the most recent classification of odontogenic and maxillofacial tumours (5th edition, 2022) which serves as a scaffold for the selection of typical tumour entities. Due to the educational character of this paper, only important jaw tumours worth mentioning and their characteristics are subject to be extracted from the literature and further discussed.The main focus was put onto both the description of radiological tumoral appearance and the rational selection of a radiological diagnostic work-up. In order to better visualize this difficult field of tumour entities, much attention has been paid on a comprehensive pictorial essay.For radiologists, it is their foremast task to detect, describe, and to classify bone tumours of the jaw when they are found intentionally or accidentally, resp. A close co-operation with their clinical partners is of upmost importance to gain information about patient's history and clinical presentation. It is readily reasonable that radiologists are mostly able to provide only a suggestion of the presented tumour entity but this expert opinion would be very helpful to further narrow down the list of potential differential diagnoses (e.g., differentiation of a cyst vs. solid tumour osteolysis, identification of jaw osteomyelitis vs. tumoral infiltration, recognizing of secondary tumour involvement of the jaw). · primary bone tumours of the jaw are very rare, moreover difficult to differentiate radiologically, and do need therefore histological proof;. · profound knowledge about tumour characteristics (location within the jaw, relationship to the tooth, bony destructive pattern) may allow a rough orientation and classification;. · matrix-forming tumours and dysplasias of the jaw facilitates their radiological differentiation and classification;. · in contrary, osteolyses should be thoroughly scrutinized for the more frequent gnathic cysts in differentiation of rather rare solid primary tumours;. · an interdisciplinary round-table discussion amongst well-experienced maxillofacial surgeons and specialized radiologists may be appropriate to avoid severe misinterpretations.. · Grieser T, Hirsch E, Tödtmann N. Bone Tumors of the Jaw - the "Blind Spot" for Radiologists Experienced with Tumors? - Part I. Fortschr Röntgenstr 2024; DOI 10.1055/a-2415-8880.

Intermittent Bleeding from the Iridocorneal Angle and Subsequent Ghost Cell Glaucoma Following Gonioscopy-Assisted Transluminal Trabeculotomy: A Case Report.

This study aims to present a case involving intermittent bleeding from the iridocorneal angle following gonioscopy-assisted transluminal trabeculotomy (GATT) surgery, followed by the development of ghost cell glaucoma (GCG). A 25-year-old man with a history of post-traumatic angle recession glaucoma underwent uneventful 360° GATT surgery. Two weeks after the surgery, while the reason for the incomplete resolution of hyphema remained unclear, intermittent bleeding from the iridocorneal angle and hemorrhage in the inferior vitreous were observed during the patient's follow-up examination. Although bleeding was controlled with intravenous tranexamic acid therapy, the patient required pars plana vitrectomy due to the development of GCG. Despite medical treatment, the patient's intraocular pressure (IOP) remained elevated during follow-ups, leading to the decision to perform Ahmed Glaucoma Valve implantation surgery as a final intervention. At the latest evaluation, the patient's IOP was under control without medication. Following GATT surgery, the possibility of intermittent bleeding from the iridocorneal angle should be considered if the hyphema persists beyond the expected duration. Hospitalization and closer patient monitoring may be necessary to detect intermittent bleeding.

Hydrodynamics investigation of a three-dimensional fish swimming in oblique flows by a ghost cell method

Fish in nature can encounter various flow environments. This paper numerically simulated a 3D (three-dimensional) carangiform fish swimming in oblique flow. The numerical model adopts a robust ghost cell method with graphics processing unit acceleration. The dynamic performance and the 3D wake evolutions are discussed under different Strouhal numbers and attack angles. It is found that the thrust along the swimming direction would get enhanced with more energy consumption as the Strouhal number (St) rises. The attack angle can get the similar but less significant effect. Also, the stall angle of θ = 40° is approximately determined, which is independent of the Strouhal number. However, the flexible deformation can reduce the adverse effects of the stall. In terms of the wake structures, they are transitioned from the two rows of vortex streets at St = 0.2 to the three rows at St = 0.6, and even to the four rows at St = 1. The connected oblique vortex ring rows induced by the undulating caudal fin contributes to the thrust and lateral forces dominantly. As the St rises, the vortex ring rows is transformed from the typical von Karman vortex streets to the reverse one, indicating the generation of thrust. The slender, parallel vortex contrails are caused by the detachment of leading-edge vortices (LEVs), and they induce the high-order harmonic components in force coefficients. The oblique angle of the vortex rings grows with the Strouhal number, while it is hardly affected by the attack angle. As the attack angle grows, the wake is turned from the disconnected hairpin vortices to the intertwined vortex rings and losses the spanwise symmetry. Moreover, the reattachment of the LEV is not observed after the stall angle.

Genotoxic and Cytotoxic Activities of Cornhusk Extract of Zea mays and Leaf Extract of Sacharum officinarum

Zea mays husk and Saccharum officinarum have been used for years in ethnomedicine for their antimalarial, anti-inflammatory, antipyretic, antidiabetic, and antiphlogistic activities. The cytotoxic and genotoxic effects of Zea mays husk and Saccharum officinarum leaf extracts on the root meristem cells of Allium cepa were investigated. Onion bulbs were exposed to 2.5 mg/ml, 5mg/ml, and 10 mg/ml concentrations of the extracts for macroscopic and microscopic analysis. Tap water was used as a negative control and Methotrexate (0.1 mg/ml) was used as a positive control. There was statistically significant (p &lt; 0.05) inhibition of root growth depending on concentration by the extracts when compared with the negative control group. All the tested extracts were observed to have cytotoxic effects on cell division in A. cepa. The extract induced chromosomal aberrations and micronuclei (MNC) formations in A. cepa root tip cells were significant (p&lt;0.05) when compared with the control group. The extracts treatment further induced cell death, ghost cells, cells membrane damage, and binucleated cells. The Zea mays husk extract was found to exhibit higher cytotoxic and genotoxic potential than Saccharum officinarum leaf extract. These results suggest that Zea mays husk and Saccharum officinarum leaf extracts possess cytotoxic and genotoxic effects on A. cepa.

PERITONEAL KERATIN GRANULOMAS MIMICKING PERITONEAL CARCINOMATOSIS: A POTENTIAL DIAGNOSTIC PITFALL

Abstract Introduction/Objective Keratin granulomas from a primary uterine cancer can present as peritoneal tumor nodules, mimicking peritoneal carcinomatosis. Endometrial adenocarcinomas with viable peritoneal tumor implants and/or involvement of bladder or bowel mucosa are categorized as stage IV disease. We present a rare case of endometrial adenocarcinoma of the uterus with squamous differentiation and multiple peritoneal nodules of keratin granulomas, masquerading as peritoneal carcinomatosis. Methods/Case Report A 68-year-old female with insignificant past medical history presented with complaints of postmenopausal bleeding for the past four months. Physical examination was unremarkable. Transvaginal ultrasound showed a 4.9 cm echogenic mass in the uterus. The endometrial biopsy showed squamous debris with atypical cells suspicious of malignancy. Endometrial curettings revealed endometrial adenocarcinoma, endometrioid type with squamous differentiation, FIGO Grade 1. Subsequently, she underwent hysterectomy with bilateral salpingo- oophorectomy. Intraoperatively, multiple suspicious nodules on the sigmoid colon and in the pelvis were identified, of which excisional biopsies and pelvic peritoneal washing were taken. Microscopic examination of the resection confirmed endometrial adenocarcinoma, FIGO Grade 1, nuclear grade 1, with extensive foreign body giant cell reaction to dead squamous cells (ghost cells). Cytologic examination of the peritoneal washing was unremarkable and excisions of the sigmoid serosal and peritoneal nodules showed pink eosinophilic laminated nodules surrounded by inflammatory cells including plasma cells, lymphocytes and multinucleated giant cells without any viable tumor cells. Results (if a Case Study enter NA) NA Conclusion Keratin granulomas are a foreign body reaction to keratin deposition from the squamous component of endometrioid adenocarcinoma. The pathogenesis of this foreign body response to keratin is considered to be a trans- tubal spread of keratin through retrograde shedding from the fallopian tubes. In the absence of viable tumor cells, it appears to have no negative prognostic significance. Careful microscopic examination of peritoneal keratin granulomas is imperative to avoid erroneous upstaging of the tumor and the subsequent advanced treatment.

Pilomatrix-like breast carcinoma: A mammary analog of pilomatrix-like high-grade endometrioid carcinoma (PiMHEC).

To describe what is, to our knowledge, the first recognized case of a triple-negative breast carcinoma (TNBC) with a PiMHEC-like phenotype.Pilomatrix-like high-grade endometrioid carcinoma (PiMHEC) is a high-grade carcinoma with divergent differentiation resembling cutaneous pilomatrix carcinoma that was recently described in the endometrium and ovary. For reference, pertinent features of PiMHEC include (1)high-grade basaloid to squamoidmorphology withthe presence of ghost cells; (2) only focal p63 and/or p40 expression despite a squamoid appearance; (3) CTNNB1 mutation, accompanied by diffusely aberrant β-catenin expression and LEF1 and/or CDX2 expression; and (4) loss of site-specific markers (ie, PAX8, ER). Here we report the histologic, immunophenotypic and molecular genetic features ofa case of a triple-negative breast carcinoma (TNBC) with a PiMHEC-like phenotype. The tumor developed immediately adjacent to a HER2+, androgen receptor (AR)+, GATA3+ conventional grade 3 invasive ductal carcinoma (IDC) with only membranous β-catenin expression. The PiMHEC-like component had all of the above-noted morphologic and immunophenotypic features of endometrial PiMHEC but with loss of GATA3 and AR rather than PAX8 and ER.Molecular analysis performed on both tumor components demonstrated a shared TP53 point mutation and an exon 3 CTNNB1 mutation restricted to the PiMHEC-like component, implying a clonal relationship with secondary acquisition of CTNNB1. Following neoadjuvant chemotherapy, the HER2+ conventional component had completely resolved, but the PiMHEC-like component had very little response. This case demonstrates that a PiMHEC-like phenotype may be seen as a form of TNBC that can develop from conventional IDC, with loss of site-specific biomarkers, acquisition of CTNNB1 mutation, and resistance to conventional chemotherapy.

Clinical and Histopathological Perspectives of Pilomatrixoma: A Case Report.

Pilomatrixoma is a rare, benign tumor arising from hair follicle matrix cells, commonly seen in children and young adults. This case report discusses an 8-year-old male with a progressively enlarging posterior neck swelling over three months. Clinical examination revealed a mobile, subcutaneous mass. Fine-needle aspiration cytology (FNAC) suggested an adnexal tumor, characterized by cohesive clusters of basaloid cells, nucleated and anucleated squamous cells, and ghost cells. The patient underwent surgical excision of the mass, and histopathological examination confirmed a diagnosis of pilomatrixoma. Postoperative recovery was uneventful, with no signs of recurrence at the three-month follow-up. This case highlights the importance of combining clinical, cytological, and histopathological findings to accurately diagnose and manage pilomatrixoma, emphasizing the role of complete surgical excision in achieving favourable outcomes. The report adds valuable insights to the literature, aiding clinicians in recognizing and differentiating this rare tumour in paediatric patients.

Generation of empty cell envelopes of Streptococcus pyogenes using biosurfactants

BackgroundBacterial ghost cells (BGCs) are cell envelopes that devoid of cytoplasmic and genetic contents in purpose of variable applications, including their great potential as vaccine candidates and their effectiveness as delivery systems for drugs and proteins. To our knowledge, this is the first study to produce Gram-positive BGCs by treating Streptococcus pyogenes (S. pyogenes) ATCC 19615 with Tween80 (TW80) or TritonX-100 (TX100), followed by preliminary testing of their antigenicity and safety in NIH/Ola-Hsd mice. The produced BGCs were confirmed by the presence of intact cells under a light microscope, the absence of growth signs upon re-cultivation. The transmembrane tunnels were visualized using a scanning electron microscope, and subsequently, considerable quantities of released DNA and protein were detected in the culture supernatant of the BGCs. The antigenicity of the produced BGCs was tested through three intra-nasal immunization doses followed by infection. Afterward, the opsonic activity and the IgG levels were measured, followed by a comprehensive histopathological examination for selected tissues and organs.ResultsThe sera of immunized mice exhibited a significant rise in both opsonic activity (TW80 produced BGC = 68% and TX100 produced BGC = 75%) and IgG levels (TW80 produced BGC = a threefold increase and TX100 produced BGC = a fourfold increase) when compared to the positive control group "non-immunized challenged with ATCC 19615." Histopathological analysis revealed that the BGCs produced by TW80 are relatively safer and have a less severe impact than those produced by TX100.ConclusionThe study's findings suggest that Sp-BGC/TW80 is initially effective and safe in vivo. However, further pre-clinical studies are necessary to confirm its effectiveness and ensure complete safety, specifically in terms of the absence of autoimmunity and antibody cross-reactivity with myosin proteins in human cardiac tissues.

Ghost cells: Wilder Penfield and the characterization of glia and glial pathology, 1924–1932

ABSTRACT Wilder Penfield is known for his contributions to the structure–function relationship of the brain and for the surgical treatment of focal epilepsy. Less well known are his contributions to the study of glial cells and his investigation of their role in human neuropathology. Penfield learned the gold and silver methods for staining neurons, glial cells, and their projections from Charles Sherrington and Pío del Río-Hortega. He and his colleague William Cone established a laboratory for the study of glial cells and human neuropathology using metallic stains, initially at the Presbyterian Hospital in New York City in 1925, and then at the Montreal Neurological Institute in 1928. Penfield, Cone, and their research fellows, building on the findings of Río-Hortega, confirmed the existence of oligodendrocytes and their relationship with myelin, and investigated the putative mesodermal origin of microglia. They discovered the reaction of oligodendrocytes to pathological stressors, and the phagocytic activity of microglia in human gliomas. In this article, we argue that Penfield’s studies of astrocytes, oligodendrocytes, and microglia, and their responses to craniocerebral trauma, epilepsy, malignant brain tumors, and other pathologies of the central nervous system inaugurated a new era in clinical neurocytology and neuropathology.

Malignant Recurrence of Benign Odontogenic Tumors (A Single Center Cross-Sectional Study)

BackgroundDespite their rarity, malignant odontogenic tumors (MOT) represent an important group of oral lesions characterized by their variable clinical presentations and sometimes unexpected biological behavior.ObjectivesThe purpose of this retrospective cross-sectional study was to evaluate the number, types, and frequency of MOT and to investigate the relative rate of malignant transformation in recurrent odontogenic tumors (OT).MethodologyThe records of patients diagnosed with OT in the hospital of the Faculty of Dentistry, Cairo University, were reviewed over 10 years (2013-2022). The OT were investigated for frequency, age, gender, site, and recurrence. The data were recorded and then analyzed using SPSS software version 25.ResultsAmong 5543 oral excisions, 357 cases of them were OT, including 336 benign (94.1%) and 21 malignant neoplasms (5.9%). Among the odontogenic malignancies, 18 lesions (85.7%) appeared de novo, and 3 lesions (14.3%) developed as recurrent of previously classified benign tumors. A high incidence was observed in the middle and old age groups (90.4%) with a median age being 42. Slight male predilection (1.3:1) was noticed. The mandible was the highly affected site but all recurrent cases were diagnosed in the maxilla as ghost cell odontogenic carcinoma (n = 2, 66.6%) and primary intraosseous carcinoma (n = 1, 33.3%).ConclusionRetrospective analysis of the relative frequency of MOT and the documentation of the unusual recurrence of benign OT as a malignancy enhances our understanding of OT behavior and the need for appropriate therapy and clinical follow-up.

Investigating the pro-inflammatory differentiation of macrophages with bacterial ghosts in potential infection control.

In the complex realm of bacterial infections, particularly those caused by Staphylococcus aureus (S. aureus), macrophages play a pivotal role in orchestrating the immune response. During the initial stages of infection, the monocytes give rise to macrophages with a pro-inflammatory (M1 type) behaviour, engulfing and neutralizing the invading pathogens. However, under the sustained influence of S. aureus infection, monocytes can undergo a transition into an anti-inflammatory M2 state (pro-infection) rather than the M1 state (anti-infection), thereby compromising effective infection control. Therefore, it is necessary to develop a strategy that would preserve the pro-inflammatory functions of macrophages, in a safe and controlled manner. For this, we focused on harnessing the potential of S. aureus-derived ghost cells (GCs) which are non-live empty envelopes of bacterial cells, but with the antigenic determinants intact. Through a unique Lugol's-iodine treatment, we generated GCs and characterization of these GCs using gel electrophoresis, FTIR, flow cytometry, TEM, and SEM confirmed their structural integrity. Following this, we assessed the extend of cellular association of the GCs with RAW267.4 macrophages, and observed an immediate interaction between the two, as evident from the flowcytometry and microscopy studies. We then performed macrophage polarisation on a human monocyte-macrophage model cell line, THP-1. Our findings revealed that GCs effectively activated macrophages, and promoted a pro-inflammatory polarisation with the expression of M1 differentiation markers (CD86, TNFα, IL-1β, IL-6, IL-12) evaluated through both qPCR and ELISA. Interestingly an intermediary expression of M2 markers viz., CD206 and IL-10 was also observed, but was overruled by the enhanced expression of M1 markers at a later time point. Overall, our study introduces a novel approach utilizing GCs to guide naïve macrophages towards M1 subtypes, thereby potentiating immune responses during microbial infections. This innovative strategy can modulate macrophage function, ultimately improving outcomes in S. aureus infections and beyond.

An improved dynamic bidirectional coupled hydrologic–hydrodynamic model for efficient flood inundation prediction

Abstract. To improve computational efficiency while maintaining numerical accuracy, coupled hydrologic–hydrodynamic models based on non-uniform grids are used for flood inundation prediction. In these models, a hydrodynamic model using a fine grid can be applied to flood-prone areas, and a hydrologic model using a coarse grid can be used for the remaining areas. However, it is challenging to deal with the separation and interface between the two types of areas because the boundaries of the flood-prone areas are time dependent. We present an improved Multigrid Dynamical Bidirectional Coupled hydrologic–hydrodynamic Model (IM-DBCM) with two major improvements: (1) automated non-uniform mesh generation based on the D-infinity algorithm was implemented to identify the flood-prone areas where high-resolution inundation conditions are needed and (2) ghost cells and bilinear interpolation were implemented to improve numerical accuracy in interpolating variables between the coarse and fine grids. A hydrologic model, the 2D nonlinear reservoir model, was bidirectionally coupled with a 2D hydrodynamic model that solves the shallow-water equations. Three cases were considered to demonstrate the effectiveness of the improvements. In all cases, the mesh generation algorithm was shown to efficiently and successfully generate high-resolution grids in those flood-prone areas. Compared to the original M-DBCM (OM-DBCM), the new model had lower root-mean square errors (RMSEs) and higher Nash–Sutcliffe efficiencies (NSEs), indicating that the proposed mesh generation and interpolation were reliable and stable. It can be adequately adapted to the real-life flood evolution process in watersheds and provide practical and reliable solutions for rapid flood prediction.