Prick Test Research Articles

Improvement in bioactivity, hardness and friction resistance of 3 % manganese-doped hydroxyapatite coated on alumina using radio frequency magnetron sputtering

Hydroxyapatite (HAP) is a common hard tissue implant material known for its superior biocompatibility and osteoconductivity. However, its poor mechanical strength, brittleness and slow degradation limit the applications. This study explores the enhancement of HAP mechanical properties and bioactivity by coating 3 wt% manganese-doped HAP (Mn-HAP) on another inert biomaterial alumina (Mn-HAP/Al2O3) substrates using the RF magnetron sputtering technique. Characterization of these samples was performed using Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), Grazing Incidence X-ray Diffraction (GIXRD), Fourier Transform Infrared Spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) techniques. Mechanical property was assessed through Vicker's hardness and adhesion of the film was studied by scratch testing. Corrosion resistance was evaluated using Tafel plots in Ringer's solution by Electrochemical analyser (ECA), and dielectric properties were measured using Impedance analyser. Biocompatibility was examined by wettability tests, thrombogenicity, antioxidant test, antimicrobial investigation and MTT [3-(4, 5-dimethythiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay. The results show that Mn-HAP/Al2O3 coatings exhibit superior properties as compared to pure HAP, alumina, and HAP/Al2O3. Mn-HAP showed enhanced crystallinity and grain refinement, leading to improved hardness of 1198 HV for Mn-HAP/Al2O3 as compared to 39.84 HV for pure HAP and 1028 HV for HAP/Al2O3. The friction coefficient was found to be best in the Mn-HAP/Al2O3 sample. Corrosion rate significantly decreases in Mn-HAP/Al2O3 (1.63 ± 0.28) mmpy after coating on alumina. In vitro studies demonstrated enhanced cell attachment, proliferation, and differentiation after Mn-HAP coating on alumina. Antimicrobial tests revealed improved resistance against E. coli and S. aureus, with Mn-HAP/Al2O3 showing a larger zone of inhibition. The study concludes that 3 wt% Mn-HAP coatings deposited by RF magnetron sputtering hold great promise for enhancing the performance and longevity of hard tissue implants, paving the way for advanced biomedical applications.

Effects of BRCA1 overexpression via the NRF2 / HO1 / NQO1 pathway on oral cancer cells proliferation, migration, and apoptosis

ObjectiveHerein, we explored the influences of breast cancer susceptibility gene 1 (BRCA1) overexpression on oral cancer cells proliferation, migration, and apoptosis via evaluation of its interactions with nuclear factor erythroid 2-like 2 (NRF2). DesignCAL-27 and DOK cells were transfected with a BRCA1 overexpressing lentivirus. Next, we utilized Western blot and quantitative real-time polymerase chain reaction (qRT-PCR) analyses to evaluate BRCA1, NRF2, and their target gene expressions. Using cell counting kit-8 (CCK-8) assessment, we assessed cell proliferation and a scratch test detected CAL-27 cell migration. Additionally, flow cytometry was employed used to examine cell apoptosis, while an enzyme-linked immunosorbent assa (ELISA) was employed for evaluation of 8-hydroxy-2′- deoxyguanosine (8-OHdG) expression. An immunohistochemical analysis was employed to determine the NRF2 target genes and Ki-67 expressions. ResultsBRCA1 overexpression increased the NRF2 and its target gene transcript and protein expressions. CCK-8 and scratch test results showed that BRCA1 overexpression decreased cell proliferation and weakened CAL-27 cell migratory ability. Flow cytometry results showed that BRCA1 overexpression promoted cell apoptosis in a time-dependent manner, while enzyme-linked immunosorbent assay results showed that BRCA1 overexpression decreased 8-OHdG expression levels in CAL-27 and DOK cells. Immunohistochemical analysis results showed higher expression of NRF2 target genes and Ki-67 in oral squamous cell carcinoma cells. ConclusionsExperiments involving oral cancer cells confirmed that BRCA1 overexpression could up-regulate the NRF2 signalling pathway, reduce oxidative damage, and inhibit cell proliferation and other biological behaviours. The BRCA1 and NRF2 pathways might be associated with oral cancer occurrence and development.

Oleic Acid Inhibits SDC4 and Promotes Ferroptosis in Lung Cancer Through GPX4/ACSL4.

As a common malignancy, lung cancer has a relatively poor prognosis and a low survival rate. In recent years, ferroptosis, as an emerging filed, has great promise in the potential treatment of cancer. Brucea javanica oil (BJO) is often used to treat various cancers. Oleic acid (OA) is the main ingredient of BJO. In this study, we investigated the role and molecular mechanism of OA in lung cancer treatment by promoting ferroptosis. In this study, A549 cells and H1299 cells were used for invitro experiments, and a CCK-8 test, scratch test, and MTT experiment were carried out. We examined reactive oxygen species (ROS), the JC-1 probe, glutathione (GSH) expression, lipid peroxidation, SDC4 mRNA levels, and ACSL4, SLC7A11, GPX4, and SDC4 protein levels. The results showed that OA could inhibit the proliferation and migration of A549 cells and H1299 cells, SDC4 was a potential therapeutic target of OA against lung cancer, and OA treatment significantly inhibited the expression of SDC4 in A549 cells and H1299 cells. OA induces ferroptosis in A549 cells and H1299 cells, decreases GSH levels, increases lipid peroxidation levels, and decreases SDC4 mRNA expression; in addition, OA upregulates ACSL4 expression and decreases SLC7A11, GPX4, and SDC4 expression. This study confirmed that OA could inhibit SDC4 expression and promote the occurrence of ferroptosis in A549 cells and H1299 cells through the GPX4/ACSL4 pathway, providing an effective basis for the use of drugs targeting ferroptosis in lung cancer treatment.

Integrated miRNA sequencing and experimental validation Unveil that low-level laser enhances vascular endothelial cell proliferation, migration, and lumen formation via miR-90/VEGFA

The hydroxyapatite orbital implantation is widely used to treat orbital malformation, but delayed postoperative angiogenesis can hinder conjunctival wound healing, potentially leading to implant exposure and prolapse. Low-intensity laser therapy (LLLT) is recognized for its ability to promote tissue regeneration, reduce inflammation, and alleviate pain. This study aims to explore the specific mechanism of miRNAs-VEGFA pathway regulation in early vascularization after orbital implant placement induced by LLLT. A hydroxyapatite orbital implant model was established and treated with LLLT. Vascular tissues surrounding the ocular prosthesis were extracted for high-throughput sequencing to identify differentially expressed miRNAs. miRNAs predicted to bind with VEGFA were selected for validation. GO and KEGG analyses were performed to reveal the functional enrichment of target genes regulated by these miRNAs. Dual luciferase assay, qRT-PCR, and Western blotting were used to verify the targeting relationship between miR-90 and VEGFA. The effects of miR-90 on rabbit microvascular endothelial cell function were assessed through CCK-8 assay, scratch test, and tube formation assay. High-throughput sequencing revealed 32 differentially expressed miRNAs, with 8 upregulated and 24 downregulated. miR-90 was predicted to have a high binding score and expression abundance with VEGFA and was confirmed to regulate VEGFA expression. In vitro functional tests showed that miR-90 inhibited rabbit microvascular endothelial cell proliferation, migration, and tube formation. This study is the first to demonstrate that LLLT regulates ocular prosthesis angiogenesis via the miR-90/VEGFA pathway, providing a new target for treating vascular-dependent diseases.

Novel anti-oxidation coating prepared by polymer-derived ceramic for harsh environments up to 1200 °C

Environmental barrier coatings (EBCs) are protective barriers that could prevent internal materials from oxygen and harmful agents. However, the combination between EBCs and polymer-derived ceramics (PDCs) is relatively hard but essential. In this work, an anti-oxidation coating based on PDCs is fabricated on target SiBCN ceramics by spraying. The coating reveals a uniform and continuous structure with an approximate thickness of 11.7 μm. Experiments and characterization such as oxidation, thermal shock, scratch, and electrical resistance tests were carried out to investigate the performance of coating. The results show that during the high-temperature oxidation process, the coating surface undergoes a molten phase transformation that effectively seals pores and cracks, preventing oxygen diffusion into the ceramic interior. Moreover, the coating can withstand 20 thermal shocks without failure, and firmly adheres to the substrate even after prolonged oxidation and repeated thermal cycling. Comparative analysis of temperature-resistance results demonstrates the efficacy of the coatings in protecting against oxidation up to 1200 °C. The developed PDC-EBCs here exhibit remarkable resistance to oxidation and thermal shock, along with high insulation resistivity. This strategy offers a straightforward and efficient solution for protecting electronic materials in harsh environments.

Associations of physical activity, sedentary time, and fitness with cardiovascular risk and atherosclerosis over 3 years in women with systemic lupus erythematosus

IntroductionCardiovascular (CV) diseases are among the main causes of death in systemic lupus erythematosus (SLE). Physical activity (PA) and fitness are potential protective factors against the progression of CV risk factors and atherosclerosis. AimTo analyze trends over time in PA, sedentary time (ST) and physical fitness and their associations of with traditional and novel markers of CV risk and subclinical atherosclerosis in women with SLE over a 3-year follow-up period. MethodsIn this exploratory study, 77 White Hispanic women with SLE (43.3±13.8 years) with mild disease activity were followed after 3 years (n=44). HDL and LDL cholesterol (blood samples), BMI and muscle mass (stadiometer and bioimpedance device), blood pressure (BP), pulse wave velocity (PWV, Mobil-O-Graph® monitor), carotid plaques and intima–media thickness (General Electric Medical Systems, LOGQ-6 model) were assessed. PA and ST were measured using triaxial accelerometers. Physical fitness was assessed with the back-scratch, handgrip strength, 30-s chair stand, and 6-min walk, tests. ResultsAfter 3 years, LDL-c (estimated mean change [est]=13.77mg/dL) and PWV (0.13m/s) increased while diastolic BP (−2.80mmHG) decreased (all, p<0.05). In mixed models, 6-min walk test was positively associated with HDL-c (est=0.07); back scratch (est=0.33) and chair-stand (est=1.19) tests were positively associated with systolic BP (all, p<0.05). No other trends or associations over time were identified (all, p>0.05). ConclusionsPA, ST, fitness, and most studied CV risk factors remained stable over time, with only marginal changes in LDL-c, PWV, and diastolic BP. Overall, PA and ST were not longitudinally associated with CV risk factors and subclinical atherosclerosis and contradictory weak associations were found for physical fitness.

Allergen sensitization patterns concerning different governorates in Egypt: a retrospective study

Background Allergic disorders afflict 22% of the world’s population. Treatment and prevention of allergic diseases are dependent on correctly identifying the causal allergens and implementing appropriate avoidance approaches. We aimed to assess the variation in patterns of allergen sensitization among patients with allergic disorders in different Egyptian governorates. Methods This retrospective study included patients with allergic disorders attending an allergen immunotherapy outpatient clinic. Demographic data, diagnosis of allergic disorders, and skin prick test results of enrolled patients were retrieved from the medical records. Also, patients’ place of residence was recorded by the governorate. Results This study included 5024 patients with allergic disorders. Most of the studied patients were sensitized to mold (94.3%) followed by house dust mites (74.7%) and hay dust (69%). There was no statistical difference in allergen sensitization patterns in different Egyptian governorates. However, there was a statistically significant relation between allergic rhinitis and mixed pollen 1 (P value 0.02) and mite (P value 0.001). For bronchial asthma, both dog hair and chicken feather sensitization patterns showed a strong association with P values 0.02 and 0.03, respectively. Atopic dermatitis had a significant association with both mites (P value 0.001) and barely (P value 0.02). Conclusion The sensitization patterns did not significantly differ between the Egyptian governorates. However, it is significantly associated with allergic disorders. The most prevalent sensitization pattern in Egypt was mold.

Niraparib Enhances and Synergizes with Ganglioside GD2 to Potentiate its Inhibitory Effect on Bladder Cancer Cells.

This study aimed to study the inhibitory effect of niraparib alone or in combination with GD2 specific antibody on Bladder Cancer (BCa). The migration ability of BCa cells was assessed through a scratch assay. CCK-8 assay was performed to evaluate the viability of BCa cells, and Transwell invasion assays were utilized to examine invasive capacity. The expression levels of E-cadherin and vimentin in BCa cells were measured using QRT-PCR. Western blot showed the EMT level to be the lowest in the niraparib+GD2 group. The transwell invasion assay suggested that the invasion ability of BCa cells was weakened in the niraparib+ GD2 group. CCK8 assay indicated that the proliferation ability of BCa cells was decreased. Scratch test suggested that the migration ability of BCa cells was weakened. PCR result showed that the niraparib + GD2 group had the most significant inhibitory effect on mRNA expression of EMT markers. Niraparib combined with a GD2-specific antibody exerted a more prominent inhibitory effect on BCa.

Insights into Structural Changes During Scratch Deformation of Ductile Coating Systems: Plastic Flow, Microstructural Transformations, and Crack Development

This study investigates the structural changes occurring during the scratch deformation of ductile materials, focusing on a composite aluminum (Al) coating on a steel substrate fabricated using a solid-state aluminizing technique. By analyzing the results of the scratch test with transmission electron microscopy (TEM) and focused ion beam (FIB) techniques, the research provides a detailed examination of plastic flow, microstructural transformations, and crack development. Results demonstrate that strong adhesion at the interface and similar mechanical properties between steel and Al layers facilitate co-deformation, crucial for maintaining the integrity of the composite structure. The study features the formation of a rolling-like laminated structure and significant grain refinement in both the steel and Al components, driven by plastic deformation. Observed atomic-scale intermixing and the formation of an amorphous interlayer highlight extensive material interactions during deformation. The visualization of crack progression using FIB allows for an in-depth understanding of the fracture process. Subsurface cracks initiate within the thin Al interlayer and propagate toward the surface, evolving through the coalescence of nanopores into microvoids and larger cavities, ultimately leading to crack propagation. Secondary internal cracks may arise due to stress fields generated by the primary crack, contributing to a complex network of internal cracks.

Microstructures, phase and mechanical characterisation of Al2O3-ZrO2-TiO2 coating produced by atmospheric plasma spraying

The microstructure, crystallographic phases, and mechanical properties of a newly developed Al2O3 – TiO2 – ZrO2 ternary ceramic coating were characterized. The coatings were produced by atmospheric plasma spraying as a preblended powder on Ti-6Al-4 V substrates using the new generation of the Debye-Larmor cascaded plasma torch. The 400 μm thick as-sprayed ternary ceramic coating is compact and neither delamination nor inter-/trans-granular cracks were found. The coating consists of single phase α-Al2O3, monoclinic m-ZrO2, and a nanocrystalline dual phase structure of α-Al2O3 and m-ZrO2. Ti is either present as ZrTiO4 or as solute in the dual phase. Cracking from the tip of the indent is rare and delamination was not observed after the progressive scratch test. The coating has potential in high wear applications for example in medical devices.

Synthesis and characterization of ZnO and CuO coatings for antibacterial and antiviral applications

Copper oxide (CuO) and Zinc oxide (ZnO), coating have attracted attention for their potential antiviral properties, including their ability to combat virus. This study focuses on the development and characterization of self-disinfecting surface passivation films composed of CuO and ZnO, obtained using the spin-coating technique. The research aims to develop surfaces that can actively eliminate harmful microorganisms, reducing the risk of infections, while also offering strong mechanical resistance and adhesion to withstand external factors, which is crucial for ensuring long-term effectiveness. Additionally, the microstructural properties of the elaborated films were analyzed using SEM/EDS, which stands for Scanning Electron Microscopy/Energy Dispersive X-ray Spectroscopy and X-Ray diffraction analysis (XRD). The mechanical behavior was assessed through Vickers hardness and scratch resistance tests. It was found a dense and homogeneous thin films. The hardness of CuO and ZnO films were 11.14 ± 0.04 GPa, and 8.89 ± 0.04 GPa respectively. Therefore, scratching tests revealed high adhesion properties with a critical load LC1 of 1.89 ± 0.02 N and 1.04 ± 0.02 N for CuO and ZnO films respectively. Then, this study revealed that CuO and ZnO films exhibit excellent antimicrobial activity against Staphylococcus aureus ATCC 29213, as well as outstanding antiviral activity against the HSV-2 virus.

Proapoptotic and antimigration properties of osthole in combination with LY294002 against human glioma cells.

Anaplastic astrocytoma and glioblastoma multiforme are infiltrating and vascularized gliomas with a high degree of chemoresistance and metastasis. Our previous studies have shown that osthole may be of great importance in the treatment of gliomas. Therefore, in this work, for the first time, coumarin was used in combination with LY294002-an inhibitor of the PI3K-Akt/PKB-mTOR pathway, which is overly active in gliomas. MOGGCCM and T98G cells were incubated with osthole and LY294002, alone and in combination. Staining with specific fluorochromes was used to visualize cell death and the scratch test to assess the migration. The level of proteins was estimated by immunoblotting. Forming protrusions were visualized by SEM, and immunocytochemistry was used to determine the localization of proteins. Additionally, the expression of Bcl-2, beclin 1 and Raf kinase was silenced using specific siRNA. The obtained results showed that osthole in combination with LY294092 effectively inhibited the migration of glioma cells by reducing the level of metaloproteinases and Rho family proteins, as well as decreasing the level of N-cadherin. In addition, the combination of compounds induced apoptosis. New combination of compounds shows a high pro-apoptotic potential and also inhibits the migration of gliomas cells.

Microstructure, mechanical and tribological characterization of magnetron sputtering ZrN and ZrAlN coatings

In this research paper, mechanical and tribological characterization of novel high wear-resistant ZrN-ZrAlN coatings are presented. The varying concentrations of AlN is chosen to evaluate the influence of AlN the surface morphological, nanomechanical, and tribological properties of the composite coating. The coatings were developed on D9 steel substrates using nitrogen reactive gas radio frequency (RF) magnetron sputtering of zirconium and aluminium targets in an argon plasma. Variable power density for the aluminium target and constant power density for zirconium, was used to obtain in a systematic way, the variable concentration of AlN in the coating. Surface morphological studies were carried out to evaluate composition and crystal structure using X-ray diffraction (GIXRD), Raman spectroscopy, and energy-dispersive X-ray spectroscopy (EDS). Coatings display a polycrystalline structure, but the level of crystallinity decreases with higher AlN concentration. Nanomechanical and nano scratch testing, along with tribological experimental studies were performed to comprehensively analyse performance of the developed coatings. Higher hardness of composite coating is achieved with optimal concentration of AlN in ZrN-ZrAlN coating. Adhesion strength of the coatings increased with the increase in the concentration of AlN. ZrN-ZrAlN coatings depicted low wear, however coatings containing AlN exhibits superior wear resistance.

Theory and Experiment on Rock-Cutter Interfacial Friction and Rock Mohr-Coulomb Parameter Estimations

Summary The Mohr-Coulomb (M-C) failure criteria is by far the most widely used model for granular materials (including rocks and soils) in many geotechnical industries due to its simplicity. Its parameters are conventionally obtained by performing a series of pressurized triaxial compression tests (TCTs). The peak stress from each confining pressure is plotted at a single point as the maximum vs. the minimum principal stresses. The M-C parameters are obtained by the best linear fitting through the failure envelope formed by the peak stress points of interest. The TCT is time-consuming, costly, and destructive. Is there an experiment that can provide the failure envelope with one single test, even at the atmospheric pressure? This seems impossible, at least has never been rigorously reported. In this work, we present our finding of such a test. The paper first provides the experimental setup and the theoretical solution for a hemispherical scratch test of a polycrystalline diamond cutter (PDC) at low rate of cut (ROC) and low depth of cut (DOC); the theoretical characteristic response of the test is identified and validated. Next, the formula for the rock-cutter interfacial coefficient of friction (COF) is derived, which provides a theoretical guide for the friction measurement for shaped cutters. Then, the nominal average drag and thrust stresses are evaluated, which are observed experimentally and then proved theoretically to behave in a linear relation, analogous to the M-C envelope from the TCTs. We also provide a first method that can self-consistently evaluate the M-C parameters for the crushed zone, which plays a very important role in rock cutting. By comparing the M-C results for three rocks at different loading conditions, good agreements under different scratch conditions are made against the M-C parameters for several rocks from the TCTs.

Study of the Nature of the Destruction of Coatings Based on the ZrN System Deposited on a Titanium Alloy Substrate

The fracture strength was compared in a scratch test of coatings based on the ZrN system with the introduction of Ti, Nb and Hf, which were deposited on a titanium alloy substrate. The coatings were deposited using Controlled Accelerated Arc (CAA-PVD) technology. In coatings that simultaneously include Zr and Ti, a nanolayer structure is formed, while in coatings without Ti, the formation of a monolithic single-layer structure is observed. The comparison was carried out according to two parameters: adhesion strength to the substrate and overall coating strength. The (Zr,Hf)N coating showed better resistance to destruction, but had worse adhesion to the substrate. As a result, although the coating is retained directly in the scribing groove, a large area of delamination and destruction is formed around the groove. The (Ti,Zr,Nb)N coating, with its somewhat lower strength, has a high adhesion to the substrate; no noticeable delamination is observed along the groove boundary. In this paper, not only is the fracture resistance of various coatings deposited on a titanium alloy substrate compared, but the nature of this fracture is also investigated depending on the composition of the coatings.

Using the Nintendo™ Wii to Improve Physical Function and Reduce the Risk of Falls in Older Adults: A Randomized Controlled Clinical Trial.

(1) Background: Numerous exercise programs that improve physical capacity and the risk of falls in older adults have been proposed with varying degrees of success. A novel approach may be to use a video game system that uses real-time force feedback to train older adults. The aim of this study was to evaluate the effects of a Nintendo™ Wii-based exercise program on physical function and risk of falls in older people. (2) Methods: This 12-week randomized controlled clinical trial involved 73 participants: 36 individuals participating in a control group (CG) and 37 in an experimental group (EG) participating in a combined program. Balance was measured using the Tinetti scale, flexibility was assessed with the back scratch test and the sit-and-reach test, and lower body strength was assessed with the 30 s chair stand-up test. (3) Results: The results of this study show significant improvements in balance, gait, flexibility, and strength of the lower limbs compared to a control group. (4) Conclusions: A Nintendo™ Wii-based exercise program for seniors produces improvements in the physical health of older adults. These improvements highlight the importance of integrating physical exercise through video games as an effective strategy to improve the general health and quality of life of older adults.

Clinical utility analysis of the Hoxb8 mast cell activation test for the diagnosis of peanut allergy.

Peanut allergy is among the most severe and common food allergies. The diagnosis has a significant impact on the quality of life for patients and their families. An effective management approach depends on accurate, safe, and easily implementable diagnostic methods. We previously developed a cell-based assay using Hoxb8 mast cells (Hoxb8 MCs) aimed at improving clinical allergy diagnosis. In this study, we assessed its diagnostic performance by measuring blinded sera from a prospectively enrolled and pre-validated peanut allergy cohort. Hoxb8 MCs were passively sensitized with sera from peanut-allergic and peanut tolerant children and adolescents (n = 112). Degranulation of Hoxb8 MCs was quantified upon stimulation with dose-titrated peanut extract by means of flow cytometry, using CD107a as activation marker. The results from the Hoxb8 mast cell activation test (Hoxb8 MAT) were compared to established diagnostic assays such as the skin prick test (SPT), specific IgE (sIgE) levels, and the basophil activation test (BAT). Additionally, serum samples from BAT nonresponders were assessed with the Hoxb8 MAT. Hoxb8 MAT displayed a robust dose-dependent activation to peanut extract, with a cutoff value of ≤5.2% CD107a positive cells. The diagnostic accuracy was highest at allergen concentrations ≥100 ng/mL, with an area under the receiver operating characteristic curve (AUROC) of 0.97, 93% sensitivity, and 96% specificity, outperforming traditional SPT and sIgE tests. When compared to BAT, Hoxb8 MAT exhibited comparable diagnostic efficacy. Moreover, sera from BAT nonresponders were accurately classified into allergics and nonallergics by the Hoxb8 MAT. The Hoxb8 MAT demonstrated a very good diagnostic precision in patients prospectively assessed for peanut allergy comparable to the fresh whole blood-based BAT. Additionally, it demonstrated its value for accurate classification of BAT nonresponders into allergic and nonallergic individuals. Further investigations into its utility in the routine clinical setting are warranted.

Empowering Pediatricians With Direct Penicillin Challenges: A Promising Delabeling Strategy.

Current literature supports a multidisciplinary approach to penicillin allergy delabeling. Our study aims to review the success rate of penicillin challenges performed at Walter Reed National Military Medical Center Allergy Clinic and assess the reaction rate associated with a direct oral challenge in low-risk patients. We conducted a retrospective review of the outcomes of pediatric penicillin challenges at the Walter Reed National Military Medical Center Allergy and Immunology clinic from June 2019 to May 2023. A total of 74 challenges were included in this study. Patients were initially screened to assess the date of reaction, nature of reaction, if the reaction was life-threatening, and if the patient was hospitalized or sought emergency medical care for the reported reaction. After completion of the screening questionnaire, a direct graded challenge was performed (without skin testing) if a patient's history was deemed low risk. Patients with a recent reaction or a history of multiple drug allergies were more likely to be directed to skin prick testing and intra-dermal testing with Pre-pen and Penicillin-G prior to challenge. All patients passed all challenges. Thus, there was a 100% pass rate for both direct challenges and skin test with oral challenges. Given the low rate of adverse events in this study, expansion of penicillin delabeling in the primary care setting should be considered in patients deemed to be at low risk. It is important for allergists to empower and educate their peers and push forward a movement to create a multidisciplinary approach to penicillin delabeling.

Effect of Ta on selective oxidation behavior and oxide film adhesion of alumina-forming austenitic alloys

The effects of Ta on the selective oxidation behavior and scale adhesion of Fe-45Ni-25Cr-4Al-1.5Nb-0.4C-xTa (x=0.6, 0.9, 1.2, 1.5 wt%) austenitic alloys at high temperature under low oxygen pressure were investigated. The FCC, MC-(Ta, Nb)C, M23C6 and B2-NiAl phases were found in the annealed alloy. Addition of Ta significantly promoted the formation of an external Al2O3 layer and inhibited growth of Cr2O3 and spinel at 850 °C under oxygen pressures of 10−18 atm and 10−24 atm. Similar oxidation behavior was observed in two-step oxidation process (650 °C for 8 hours and 1000 °C for 16 hours). Ta and Nb preferentially segregated at the interface between the oxide scale-matrix as well as grain boundary within the oxide scale during oxidation, and inhibited outward diffusion of Al and Cr. A large oxygen activity gradient was formed in the oxide film, resulting in the formation of columnar grains. Due to a significant decrease in oxygen activity at the front of the reaction, selective oxidation of alumina was promoted. Furthermore, the scratch test technique was used to quantify the adhesion of oxide scales. Peg-like structures formed by Ta and Nb positively influenced the adhesion properties of the oxide scale.

Reducing metastasis ability of gastric cancer cell line by targeting MMP16 using miR-193a-5p and 5-FU

PurposeCo-administration of microRNAs and chemotherapy drugs effectively treats several cancers. The current study sought to investigate the function of matrix metalloproteinase 16 (MMP16) and miR-193a-5p in the pathogenesis of gastric cancer (GC). Materials/methodsSixty-five surgical patients, 15 receiving 5-fluorouracil (5-FU), provided GC and adjacent non-cancerous tissue. Following that, qPCR was used to assess the expression levels of MMP16 and miR-193a-5p in GC cells. The impact of miR-193a-5p and 5-FU administration on MMP16 mRNA expression was evaluated using qRT-PCR and Western blotting. MTT and Scratch tests were also conducted to assess their effects on cell viability and migration. Moreover, a rescue experiment using an MTT assay was performed. Using flow cytometry, the apoptotic rate was calculated. Finally, it was evaluated how MMP16 and miR-193a-5p related to the clinicopathological characteristics of the patients. ResultsThe current study found that while MMP16 expression increased in GC patients (P ​< ​0.0001), miR-193a-5p expression significantly decreased (P ​< ​0.001). MMP16 down-regulation was another effect of miR-193a-5p replacement, particularly when 5-FU was added (P ​< ​0.01). In addition, this study found that miR-193a-5p, by concentrating on MMP16, decreased the migration of GC cells brought on by MMP16. In GC cell lines, miR-193 and 5-FU induce apoptosis, with the 5-FU being more pronounced when combined with mir-193, according to flow cytometry results. A strong correlation was also found between clinicopathological traits associated with MMP16 and miR-193a-5p. ConclusionsThese findings suggest that miR-193a-5p, in conjunction with 5-FU, down-regulates MMP16 in GC, where it suppresses tumor growth.