Tissue Reaction Research Articles

Neuroprotective effect of Naochuxue prescription on intracerebral hemorrhage: inhibition of autophagy downregulating high mobility group box-1.

To determine the molecular mechanisms underlying the neuroprotective effects of Naochuxue prescription (,NCXP) in rats with intracerebral hemorrhage (ICH). Sprague-Dawley rats were injected with collagenase to generate ICH models, which were then randomly divided into six groups, including control, sham, model, and three intervention groups. The intervention groups received different doses of NCXP (0.13, 0.26, and 0.52 g/kg) daily for 10 d. High-performance liquid chromatography (HPLC) was used to analyze the chemical characteristics of NCXP. The neurobehavioral outcomes of the rats were evaluated using neurological deficit scores (Zea Longa 5) and the corner turn test. Pathomorphological changes in perihematomal tissues after ICH were observed using hematoxylin and eosin staining. Immunohistochemistry (IHC) was used to detect the inflammation expression of interleukin 6 (IL-6) and toll-like receptor 4 (TLR4). High mobility group box-1 (HMGB1), Beclin1, microtubule-associated protein 1 light chain 3 beta (LC3), and sequestosome 1 (p62) were detected using real-time quantitative polymerase chain reaction and Western blotting in perihematomal tissues. HPLC showed that the NCXP had good stability. Rats with ICH had severe neurological function deficits compared to the control group. IHC results showed that NCXP significantly downregulated the expression of the inflammatory proteins IL-6 and TLR4. ICH rats treated with NCXP showed less neurological injury than the model group, accompanied by a significantly decreased expression of HMGB1, Beclin1, and LC3 and an increased expression of p62. The neuroprotective effect of NCXP alleviated inflammation and autophagy possibly by downregulating HMGB1 expression. However, further research on the signaling pathways is required to verify this hypothesis.

Unraveling the Function of Stress Kinase in the Progeny of Soybean Plants Grown from Low-Temperature Pretreated Seeds

The research work was carried out with the progeny of two soybean cultivars, Richy and Izidor, from the years 2019 and 2020. Plants were grown from seeds pretreated with low temperature (2–5 °C) before sowing for two periods of treatment: 12 days marked as “treated control” (tr. K) and 22 days marked as “treated” (tr.); and “non-treated” (K0) used as a control. Transcriptional profiles of the gene encoding a stress protein kinase were evaluated after the application of abiotic stresses caused by the following: 150 mM NaCl solution/salinity stress/for 24 h; 350 mM mannitol solution/drought stress/for 24 h; and low temperature (4 °C) for 72 h. Transcript levels were established by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) in leaf tissue collected from seedlings of the 2019 and 2020 progeny of “tr. K”, “tr.”, and “K0” samples. Analyses determining the quantity of malondialdehyde (MDA) and total antioxidant capacity (TAC) were performed. The expression of investigated stress kinase was highly upregulated after the application of abiotic stress caused by 150 mM solution of NaCl and to a lesser extent by 350 mM solution of mannitol. Detected transcript levels depend on the type of sample out of “tr. K”, “tr.”, and “K0”; the progeny; and the genotype.

Do Intra-articular Metal Ion Levels Predict Adverse Local Tissue Reaction in Revision Total Hip Arthroplasty for Mechanically Assisted Crevice Corrosion?

BackgroundMechanically assisted crevice corrosion is a complication that may occur in vivo at modular metal interfaces following metal-on-polyethylene total hip arthroplasty (THA). Metal ions released in vivo may be associated with adverse local tissue reactions (ALTRs). While there is no definitive value, high serum ion levels are implicated as contributors to ALTR, and various screening levels have been recommended. The purpose of this investigation was to evaluate the relationship between synovial fluid (SF) cobalt and chromium ion levels and the risk of developing ALTR. MethodsThis was a retrospective cohort study of 552 patients who underwent 621 metal-on-polyethylene primary THAs. A total of 69 patients underwent revision THA due to symptomatic primary failure with elevated serum metal ions levels. There were 28 who had preoperative serum and intraoperative SF chromium and cobalt samples. Patient demographics, surgical, and laboratory data were collected. Descriptive statistics, Mann-Whitney U, analysis of variance tests, and linear regression analyses were performed. ResultsThere were 40.6% of revisions that had preoperative serum and intraoperative SF samples. The mean time to revision was 5.7 (range, 3.8 to 7.6) years. Mean SF cobalt and chromium levels were 870.9mcg/L (range, 1.1 to 8,300.0) and 573.5mcg/L (range, 1.3 to 10,000.0). Mean serum and SF cobalt-chromium ratios were 4.0 (range, 0.9 to 7.1) and 6.4 (range, 0 to 15.1), respectively. Elevated serum cobalt levels were predictive of ALTR (P = 0.002), SF levels were not. Analysis of preoperative serum to SF cobalt-chromium ratios showed poor correlation (R2 = 0.05). ConclusionsThere was no correlation between SF ion levels and ALTR. Also, serum and intra-articular ion levels did not correlate. The SF levels did not provide additional value over serum levels for diagnosis or prognosis of mechanically assisted crevice corrosion. Further studies are needed to better understand the relationship between serum and SF ion levels and its relationship to ALTR.

Spectrum of orbital fat necrosis in rhino-orbital-cerebral mucormycosis in post-COVID-19 patients.

Rhino-orbital-cerebral mucormycosis (ROCM) is the most common presentation of mucormycosis. Sinonasal-orbital debridement with exenteration is a life-saving procedure in ROCM patients in view of severe involvement of sinuses and the eyeball. Following the second wave of coronavirus disease 2019 (COVID-19), there was a massive surge in mucormycosis cases in India in post-COVID-19 patients. Of over 300 cases of mucormycosis admitted in our hospital, many underwent exenteration and these specimens were evaluated histopathologically, where fat necrosis was found to be a prominent finding. The spectrum of fat necrosis in ROCM in orbital fat has not been described in literature. Hence, we sought to evaluate the significance and spectrum of orbital fat necrosis in ROCM. This 3-month retrospective study included 15 cases of ROCM which underwent exenteration. Clinical data, radiologic details, and histopathologic findings were tabulated. Sections were also subjected to Periodic acid Schiff (PAS) and Gomori's methenamine silver (GMS) stains for confirming the fungus. All 15 cases showed fat stranding on computed tomography (CT) scan. On histopathologic examination, various tissue reaction patterns observed included acute/chronic inflammatory infiltrate, suppurative granulomas with giant cells, coagulative and fat necrosis, broad aseptate fungal hyphae with or without angioinvasion, and neural invasion. Fungal hyphae were confirmed with PAS and GMS stains. The spectrum of fat necrosis observed in all the cases included 1) acute necrotizing fat necrosis, 2) ghost adipocytes with or without saponification, and 3) crystalline/gouty fat necrosis. Fat necrosis is a significant finding in ROCM, both on CT scan and histopathology. All three patterns of fat necrosis may be observed simultaneously in a case of ROCM.

Assessment of Optical and Scanning Electron Microscopies for the Identification and Quantification of Asbestos Fibers and Typical Asbestos Bodies in Human Colorectal Cancer Tissues

Asbestos research, identification, and quantification have been performed over the years, and the relationship between fiber inhalation and lung disease development is well defined. The same cannot be said for the gastroenteric system: the International Agency for Research on Cancer (IARC) believes that colorectal cancer (CRC) could be associated with asbestos exposure, but research has not demonstrated a casual nexus between exposure and CRC, despite highlighting an association tendency. The combination of scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) is the most applied technique in asbestos fiber identification in tissues and intestinal mucosa. In this study, SEM/EDS was applied to evaluate the presence of asbestos fibers and bodies (ABs) inside the tissue of eleven patients affected by CRC who had undergone environmental exposure due to living in an asbestos-polluted area where an Eternit plant had been active in the past. This technique was coupled with optical microscopy (OM) to verify whether the latter could be applied to evaluate the presence of these mineral phases, with the goal of understanding its suitability for identifying fibers and ABs in colon tissues. In addition to verifying the presence of fibers, this study allowed us to identify the deposition site of said fibers within the sample and possibly detect associated tissue reactions using OM, over a shorter time and at lower costs. Despite being a preliminary and descriptive work, the obtained results allowed us to propose a method involving first-sample OM observation to identify regulated (fibers with a length ≥ 5 μm, a thickness ≤ 3 μm, and a length/thickness ratio > 3) asbestos phases and ABs in the extra-respiratory system. In fact, OM and SEM/EDS provided similar information: no asbestiform morphology or ABs were found, but phyllosilicates and other inorganic materials were identified. This research needs to be continued using higher-resolution techniques to definitively rule out the presence of these fibers inside tissues whilst also increasing the number of patients involved.

Dynamics of perifocal reactions to the application of antimicrobial gel in one-stage hip replacement under conditions of staphylococcal infection in the experiment

Background. Local antibacterial therapy in the treatment of osteomyelitis significantly increases the effectiveness of surgical debridement.The aim of the work. To assess in an in vivo experiment the dynamics of perifocal tissue reactions to the application of an original polyvinylpyrrolidone-based antimicrobial gel in a one-stage treatment of implant-associated infection in the hip joint in rabbits.Methods. Implant-associated infection was modeled by inserting Staphylococcus aureus-infected wires into the medullary canal of the femur of rabbits (n = 12). On the day 14, we removed the wire and performed radical surgical treatment of the suppurative focus and hip replacement. The animals were divided into two groups: experimental group – with application of the original antimicrobial gel at the stage of hip replacement (n = 6); comparison group – without gel application (n = 6). For morphological studies, animals were sacrificed on the days 10, 45 and 90 after hip replacement, changes in soft tissues and the bone marrow canal were assessed, and cell populations were counted with statistical data processing.Results. The application of the original antimicrobial gel causes statistically significant decrease in the number of neutrophils in the soft tissues surrounding the implant in the comparison group at all stages. Moreover, in the experimental group, at early stages the number of lymphocytes, plasmacytes and macrophages was statistically significantly higher; on the day 45, a statistically significantly larger number of lymphocytes was registered, and on the day 90 – a statistically significantly larger number of multinucleated and epithelioid cells.Conclusion. The experiment histologically confirmed the effectiveness of application of the original antimicrobial gel to stop infectious inflammation in soft tissues and the bone marrow canal during surgical debridement of an osteomyelitic lesion followed by hip replacement. A pronounced giant cell reaction aimed at removing the polyvinylpyrrolidone-based gel requires further research in terms of its outcomes.

Magnetic resonance imaging signal changes at the intramuscular injection site in dogs: Comparison of medetomidine and saline.

Intramuscular administration is a commonly used method for delivering sedatives and anesthetics in veterinary medicine. Previous studies have reported inflammation at the intramuscular injection site in laboratory animals and observed signal changes on MRI following intramuscular injections in humans. We hypothesized that following intramuscular injection, the site would exhibit T2 hyperintensity and contrast enhancement on MRI. To investigate this, this prospective study evaluated the pattern of signal changes and grade of T2 signal intensity and contrast enhancement over time after the intramuscular injection of medetomidine at a premedication dosage, comparing it to saline. MRI scans were performed immediately postinjection into the biceps femoris and quadriceps femoris muscles, as well as at 2, 8, 24, and 72h, and 7 days postinjection. A semiquantitative scale was utilized to grade signal intensity and contrast enhancement. Both medetomidine and saline injections showed T2 hyperintensity immediately after injection and contrast enhancement from 2h postinjection, manifesting as flame-shaped. These signal changes decreased up to 24h postinjection (p<.05). The signal changes induced by medetomidine showed higher T2 hyperintense change and stronger contrast enhancement compared with saline at most time points, with the signal changes persisting for a longer duration (p<.05). These findings suggest that intramuscular administration of medetomidine induces a more severe tissue reaction compared with saline, and the results are expected to aid in the differentiation of various muscle diseases that present with similar MRI findings.

Prediction of radiotherapy toxicity: 20 years of COPERNIC radiosensitivity diagnosis procedure

PurposeSince 2004, in the frame of the care pathway, our Research Unit has replied to the demand of expertise of radiation oncologists about the individual radiosensitivity of some of their patients. This procedure, called COPERNIC, is based on a skin biopsy and the radiation-induced nucleoshuttling of the ATM protein (the RIANS model), a major actor of DNA break repair and signaling. In 2016, with the first 117COPERNIC fibroblast lines, we obtained a significant correlation between the maximum number of the nuclear ATM foci, pATMmax, and the CTCAE severity grade of the post-radiotherapy tissue reactions. In this study, we propose to verify the validity of our previous findings with a new COPERNIC data subset obtained in the 2014–2024 period. Materials and methodsWe applied a standard immunofluorescence technique to quiescent COPERNIC fibroblasts to assess, after 2Gy, the level of micronuclei, γH2AX and pATM foci. The 117 COPERNIC data published in 2016 were considered as the reference data subset. A new COPERNIC data subset composed of 133fibroblast cell lines was considered as the validating data subset. ResultsOur data showed that spontaneous or residual micronuclei levels, and residual γH2AX foci levels cannot predict CTCAE grades. Conversely, the linear formula linking the maximal number of pATM foci and the corresponding CTCAE grade and obtained in 2016 from the reference data subset fitted well the validating data. ConclusionsThe maximal number of pATM foci appears to be one of the most reliable biomarkers for predicting post-radiotherapy radiotoxicity.

Space radiation measurements during the Artemis I lunar mission

Space radiation is a notable hazard for long-duration human spaceflight1. Associated risks include cancer, cataracts, degenerative diseases2 and tissue reactions from large, acute exposures3. Space radiation originates from diverse sources, including galactic cosmic rays4, trapped-particle (Van Allen) belts5 and solar-particle events6. Previous radiation data are from the International Space Station and the Space Shuttle in low-Earth orbit protected by heavy shielding and Earth’s magnetic field7,8 and lightly shielded interplanetary robotic probes such as Mars Science Laboratory and Lunar Reconnaissance Orbiter9,10. Limited data from the Apollo missions11–13 and ground measurements with substantial caveats are also available14. Here we report radiation measurements from the heavily shielded Orion spacecraft on the uncrewed Artemis I lunar mission. At differing shielding locations inside the vehicle, a fourfold difference in dose rates was observed during proton-belt passes that are similar to large, reference solar-particle events. Interplanetary cosmic-ray dose equivalent rates in Orion were as much as 60% lower than previous observations9. Furthermore, a change in orientation of the spacecraft during the proton-belt transit resulted in a reduction of radiation dose rates of around 50%. These measurements validate the Orion for future crewed exploration and inform future human spaceflight mission design.

Evaluation of biocompatibility and osseointegration of multi-component TiAl6V4 titanium alloy implants.

This study aimed to investigate the biocompatibility and osseointegration of novel titanium (Ti) implants with a perforated part with high surface roughness (Ra >4 μm) and a smooth solid part (test group), as compared to smooth solid Ti implants (control group; Ra < 0.8 μm). Test and control implants were implanted in rabbit femurs. After 4 and 15 weeks, host tissue reaction and quality of tissue formed were evaluated with histopathology, while micro-CT scans were used to quantitatively assess bone-implant contact (BIC), surrounding bone formation, and bone ingrowth. After 4 and 15 weeks, minimal host reaction was found in the test group. Histopathological analysis showed new bone formation around the implants in both the test and control groups after 4 weeks. Furthermore, additional bone growth was often observed within the holes of the test implants. After 15 weeks, the test implants showed high bone ingrowth and the presence of mature bone in direct contact with the implant surface, whereas, bone ingrowth was poorer for the control group with 30% of the control implants, showing larger gaps at the bone-implant interface. Quantitative micro-CT analysis revealed comparable BIC and bone formation in both groups at 4 weeks, but higher BIC and more bone formation in the test group than in the control group after 15 weeks. No significant differences were observed in any of the analyses. In conclusion, partially perforated, high-roughness Ti implants showed excellent osseointegration and minimal host reaction, indicating their potential for orthopedic applications in bone repair and regeneration.

Multivariate analysis of oral mucosal ulcers during orthodontic treatment.

Orthodontic treatment can easily cause local soft tissue reactions in the oral cavity of patients under mechanical stress, leading to oral mucosal ulcers and affecting their quality of life. At present, only limited literature has explored the factors leading to oral ulcers in orthodontic treatment, and these research results are still controversial. To investigate the current status and related factors of oral mucosal ulcers during orthodontic treatment, aiming to provide a valuable reference for preventing this disease in clinical practice. A total of 587 patients who underwent orthodontic treatment at the Peking University School of Stomatology and Hospital of Stomatology between 2020 and 2022 were selected and allocated to an observation or control group according to the incidence of oral mucosal ulcers during orthodontic therapy. A questionnaire survey was constructed to collect patient data, including basic information, lifestyle and eating habits, treatment details, mental factors, and trace element levels, and a comparative analysis of this data was performed between the two groups. A logistic regression model with oral ulcers as the dependent variable was established. The regression results showed that age (≥ 60 years: odds ratio [OR]: 6.820; 95% confidence interval [CI]: 2.226-20.893), smoking history (smoking: OR: 4.434; 95%CI: 2.527-7.782), toothbrush hardness (hard: OR: 2.804; 95%CI: 1.746-4.505), dietary temperature (hot diet: OR: 1.399; 95%CI: 1.220-1.722), treatment course (> 1 year: OR: 3.830; 95%CI: 2.203-6.659), and tooth brushing frequency (> 1 time per day: OR: 0.228; 95%CI: 0.138-0.377) were independent factors for oral mucosal ulcers (P < 0.05). Furthermore, Zn level (OR: 0.945; 95%CI: 0.927-0.964) was a protective factor against oral ulcers, while the SAS (OR: 1.284; 95%CI: 1.197-1.378) and SDS (OR: 1.322; 95%CI: 1.231-1.419) scores were risk factors. Age ≥ 60 years, smoking history, hard toothbrush, hot diet, treatment course for > 1 year, tooth brushing frequency of ≤ 1 time per day, and mental anxiety are independent risk factors for oral mucosal ulcers. Therefore, these factors should receive clinical attention and be incorporated into the development and optimization of preventive strategies for reducing oral ulcer incidence.

Mapping Staphylococcus aureus at Early and Late Stages of Infection in a Clinically Representative Hip Prosthetic Joint Infection Rat Model.

Prosthetic joint infection (PJI) continues to be a devastating complication following total joint replacement surgeries where Staphylococcus aureus is the main offending organism. To improve our understanding of the disease pathogenesis, a histological analysis of infected peri-implant tissue in a hip PJI rat model was utilized to assess S. aureus spread and tissue reaction at early and late stages of infection. Sprague-Dawley rats were used and received a left cemented hip hemiarthroplasty using a 3D-printed titanium femoral stem. The rats received an intra-articular injection of S. aureus Xen36. These infected rats were sacrificed either at 3 days post-infection (early-stage infection) or at 13-days post-infection (late-stage infection). The femoral and acetabular tissues of all animals were harvested at euthanasia. Histological analysis for the harvested tissue was performed using immunohistochemistry, hematoxylin and eosin, as well as Masson's trichrome stains. Histological examination revealed significant quantitative and qualitative differences in peri-implant tissue response to infection at early and late stages. This hip PJI rat model identified clear histologic differences between early and late stages of S. aureus infection and how quickly bacterial infiltration could occur. These findings can provide insight into why certain surgical strategies like debridement and antibiotics may be associated with high failure rates.

Correlating Ultrastructural Changes in the Invasion Area of Colorectal Cancer with CT and MRI Imaging.

The cancer invasion of the large intestine, a destructive process that begins within the mucous membrane, causes cancer cells to gradually erode specific layers of the intestinal wall. The normal tissues of the intestine are progressively replaced by a tumour mass, leading to the impairment of the large intestine's proper morphology and function. At the ultrastructural level, the disintegration of the extracellular matrix (ECM) by cancer cells triggers the activation of inflammatory cells (macrophages) and connective tissue cells (myofibroblasts) in this area. This accumulation and the functional interactions between these cells form the tumour microenvironment (TM). The constant modulation of cancer cells and cancer-associated fibroblasts (CAFs) creates a specific milieu akin to non-healing wounds, which induces colon cancer cell proliferation and promotes their survival. This review focuses on the processes occurring at the "front of cancer invasion", with a particular focus on the role of the desmoplastic reaction in neoplasm development. It then correlates the findings from the microscopic observation of the cancer's ultrastructure with the potential of modern radiological imaging, such as computer tomography (CT) and magnetic resonance imaging (MRI), which visualizes the tumour, its boundaries, and the tissue reactions in the large intestine.

MRI-based radiomic analysis of soft tissue reactions near total hip arthroplasty.

This study applied radiomics to MRI data for automated classification of soft tissue abnormalities near total hip arthroplasty (THA). A total of 126 subjects with 1.5 T MRI of symptomatic THA were included in the analysis. Peri-prosthetic soft tissue regions of interest were manually segmented and classified by an expert radiologist. An established radiomics library was used to extract 96 features from 2D image patches across segmented regions. Logistic regression was employed as the primary radiomic classifier, achieving an average area under curve (AUC) of 0.71 in differentiating tissue classifications spanning normal, infected, and several inflammatory, noninfectious categories. Notably, infection cases were identified with the highest accuracy, attaining an AUC of 0.79. Statement of Clinical Significance: This study demonstrates that radiomics applied to MRI data can effectively automate the classification of soft tissue abnormalities in symptomatic total hip arthroplasty, particularly in differentiating periprosthetic infections.

Comparative Evaluation of Soft Tissue Reaction to Titanium and Polyetheretherketone Customized Healing Abutments: a Split-Mouth Randomised Clinical Trial

Aim. This study aimed to evaluate the peri-implant soft tissue response to customized healing abutments (CHAs) made of titanium and polyetheretherketone (PEEK). Methods. Titanium and PEEK CHAs were mounted on bone-level dental implants in bilateral edentulous patients in a randomized split-mouth study design. After a three-week healing period, the clinical parameters of the peri-implant soft tissues were assessed. The value of marginal bone resorption was measured by cone-beam computed tomography. In addition, peri-implant crevicular fluid samples were obtained to identify periodontal pathogenic bacteria, cytokine levels, and active neutrophil collagenase (aMMP-8) concentration. Microcirculation and oxygenation parameters were assessed using laser Doppler flowmetry and optical tissue oximetry. In addition, wavelet analysis was conducted to study blood flow control mechanisms. Results. Out of the 23 participants initially recruited, 20 were assessed after titanium and PEEK CHA installation due to losses to follow-up. The peri-implant soft tissue around 27 titanium and 25 PEEK CHAs was evaluated during follow-ups. No differences were found in the values of marginal bone resorption, cytokine levels, or total bacterial load (p&gt;0.05). PEEK CHAs demonstrated lower bleeding on probing values, less plaque accumulation, and faster relief of ischemia and hypoxia. Although aMMP-8 concentration was higher in the PEEK group, the values were within normal limits. Conclusions. The results of this comparative study showed a positive soft tissue response to PEEK CHAs. However, further studies comparing the effectiveness of different materials for CHAs should be carried out, considering their specific physical properties and processing protocols.

The Biocompatibility and the Effect of Titanium and PEKK on the Osseointegration of Customized Facial Implants.

The purpose of this study was to investigate the optimization of computer-aided design/computer-aided manufacturing (CAD/CAM) patient-specific implants for mandibular facial bone defects and compare the biocompatibility and osseointegration of machined titanium (Ma), Sandblasted/Large-grit/Acid-etched (SLA) titanium, and polyetherketoneketone (PEKK) facial implants. We hypothesized that the facial implants made of SLA titanium had superior osseointegration when applied to the gonial angle defect and prevented the senile atrophy of the bone. Histologic findings of the soft-tissue reaction, hard-tissue reaction, and bone-implant contact (BIC (%) of 24 Ma, SLA, and PEKK facial implants at 8 and 12 weeks were investigated. There was no statistical difference in the soft tissue reaction. Bone was formed below the periosteum in all facial implants at 12 weeks and the BIC values were significantly different at both 8 and 12 weeks (p < 0.05). Ma, SLA, and PEKK facial implants are biocompatible with osseointegration properties. SLA can enhance osseointegration and provoke minimal soft tissue reactions, making them the most suitable choice. They provide an excellent environment for bone regeneration and, over the long term, may prevent atrophy caused by an aging mandible. The bone formation between the lateral surface of the facial implant and periosteum may assist in osseointegration and stabilization.

Impact of cyclophosphamide on the morphological and histological changes in polyglycolic acid spacers.

In radiotherapy for pediatric abdominal tumors, determining the effect of concurrent chemotherapy on polyglycolic acid (PGA) spacers is crucial; yet this effect has not been validated. Therefore, we aimed to evaluate the impact of cyclophosphamide (CPA) chemotherapy on the PGA spacer using a rat model. Twenty-four rats were implanted with the spacer, and morphological changes in the spacer were assessed on CT for both the CPA-dosed group (40mg/kg) and the control group. The size and volume of the spacer were quantified using CT, while the degree of adhesion and microscopic examination of the tissue were determined using pathology specimens. Morphologically, the size of the spacer decreased over time in both the CPA-dosed and control groups, with no significant differences observed between groups. No significant differences in adhesion were observed between the two groups. Macrophages were observed around the PGA fibers, suggesting their involvement in the degradation of the PGA spacer. These results suggest that CPA does not cause significant clinically problematic degradation or adverse tissue reactions to the PGA spacer. This study reinforced the benefits of PGA spacers; however, future research focusing on in vivo longitudinal monitoring of individual rats, as well as on humans, is required.

Low potential of fish as a source of infection with Angiostrongylus cantonensis

Abstract Objectives Fish are hypothesized to act as paratenic hosts for the zoonotic nematode Angiostrongylus cantonensis, cause of human eosinophilic meningitis. There is a lack of data confirming the relevance of fish in A. cantonensis life cycle and their contribution to human infection. Materials and methods We conducted a series of experiments to investigate survival and infectivity of A. cantonensis larvae in Clarias gariepinus (catfish; n=30) and Oreochromis niloticus (tilapia; n=24). Each fish was inoculated with 10,000 third-stage larvae (L3). Larval survival was assessed through artificial digestion of fish tissues one, two, and three weeks post-infection. To investigate early stages of infection, four catfish were inoculated with 10,000 L3 each and sacrificed 3 days post-infection. qPCR and histopathological examinations were performed to evaluate larval distribution and tissue reactions. Two infected catfish, sacrificed one week post-infection, were used to feed Wistar rats. Results After 45 days, the rats were not shedding L1, indicating the absence of infection. One week post-infection, dead larvae were present in digested tissues of both fish species, and the same was observed two and three weeks after exposure. qPCR analysis revealed that intestine was the most heavily infected organ. Histopathology identified dead larvae within granulomas in intestines and liver. Early-stage infection experiment showed that fish sacrificed three days post-inoculation contained viable L3 which were infective to Wistar rats. Conclusions While A. cantonensis L3 can survive and remain infective in fish for a short period, they typically die within first few days post-infection. This suggests that fish may not be significant long-term paratenic hosts for A. cantonensis but may play a temporary role in its transmission to mammals (including humans) and birds. These results are consistent with previous studies on freshwater shrimps and highlight the importance of understanding aquatic host interactions in the epidemiology of this zoonotic food-borne pathogen.

Adverse tissue reactions to ORISE gel during endoscopic mucosal resection and dissection

BackgroundSubmucosal injection of lifting agents (LAs) is frequently used to facilitate endoscopic mucosal resection or endoscopic submucosal dissection. ORISE (Boston Scientific Corporation) gel, approved in 2018 by the United States Food and Drug Administration, has been commonly used until recently. Its use proliferated because of its practical prefilled syringe, prolonged lift effect, and ideal coloration. However, it has been noted to cause unexpected tissue reactions, described as “giant cell reaction” (GCR), which can obscure macroscopic and microscopic views, potentially interfering with pathologic evaluation. This study aimed to describe the adverse effects of ORISE gel. MethodsThis retrospective study analyzed pathologic specimens from all consecutive patients who received ORISE injections for attempted polyp removal and subsequently underwent segmental colon resection at our center between 2019 and 2022. A descriptive analysis was performed. ResultsA total of 45 patients were included, of whom 17 (38.0%) were female and the median age was 66 years. The indications for surgery included adenocarcinoma in 14 patients (31%), suspected malignancy in 3 patients (7%) who had benign GCR-induced masses, and other indications in 28 patients, such as large polyps or recurrent polyps after initial endoscopic treatment. Surgical procedures included right hemicolectomy (44%), low anterior resection (13%), left colectomy (11%), sigmoidectomy (7%), and abdominoperineal resection (4%). Histologic evidence of previous LA injection was seen in 31 patients (69%), with 24 patients exhibiting GCR. At final pathology, no residual neoplasm was found in 9 patients (18%); however, 14 patients (31%) had adenocarcinoma (T1 [7], T2 [3], T3 [3], and T4 [1]). ConclusionORISE gel interacts with various tissue layers of the colon, frequently resulting in GCR. This reaction and the potential subsequent mass effect formation can affect decision-making regarding the management of complex colorectal lesions. Further study into the causes and consequences of LA tissue reactions is warranted.

Comparison of radiation-shielding curtains for endoscopic retrograde cholangiopancreatography staff

Occupational radiation exposure to the eye lens of medical staff during endoscopic retrograde cholangiopancreatography (ERCP) should be kept low so as not to exceed annual dose limits. Dose should be low to avoid tissue reactions and minimizing stochastic effects. It is known that the head and neck of the staff are exposed to more scattered radiation in an over-couch tube system than in a C-arm system (under-couch tube). However, this is only true when radiation-shielding curtains are not used. This study aimed to compare the protection radiation to the occupationally exposed worker between a lead curtain mounted on a C-arm system and an ERCP-specific lead curtain mounted on an over-couch tube system. A phantom study simulating a typical setting for ERCP procedures was conducted, and the scattered radiation dose at four staff positions were measured. It was found that scattered radiation doses were higher in the C-arm with a lead curtain than in the over-couch tube with an ERCP-specific lead curtain at all positions measured in this study. It was concluded that the over-couch tube system with an ERCP-specific lead curtain would reduce the staff eye dose by less than one-third compared to the C-arm system with a lead curtain. For the C-arm system, it is necessary to consider more effective radiation protection measures for the upper body of the staff, such as a ceiling-suspended lead screen or another novel shielding that do not interfere with procedures.