Immunodiagnostic Tests in the Assessment of Specific Sensitization to M. tuberculosis in Children under the Current Epidemical Situation

The objective: to study the degree of specific sensitization according to the results of intradermal immunodiagnostic tests in children with different manifestations of tuberculosis infection under the current epidemic situation.Subjects and Methods. The degree of tuberculin sensitization was studied in 299 children from different age groups (0-14 years old) who were registered for dispensary follow-up in 2018-2019.Based on the results of a tuberculosis recombinant allergen test (TRA), the degree of specific sensitization was studied in children with tuberculin tests conversion (n = 102) and infected with Mycobacterium tuberculosis (MTB) for 2 years or more (n = 165) exposed to tuberculous infection in their families and from healthy environment, and 145 patients under 14 years old with local respiratory tuberculosis.Results. Moderate sensitization to tuberculin predominated in children with converted tuberculin test exposed to tuberculous infection in their families and those from healthy environments. According to the results of TRA test, a high degree of sensitization was observed 4.7 times more frequently in children with tuberculin test conversion exposed to tuberculosis in their families. In children from healthy environments, negative responses to TRA test were registered 2.4 times more frequently. In 73% of children infected with MTB, results of annual Mantoux tests didn’t differ much. Hyperergic reactions to TRA test in infected children exposed to tuberculous infection were 10 times more frequent than in those from healthy environments. A direct correlation was found between the high degree of sensitization to active M. tuberculosis and exposure to a tuberculosis case with a positive result of sputum test (χ2 < 0.001, p < 0.05). In the case of converted tuberculin test and infection with M. tuberculosis for 2 years or more, pronounced and hyperergic reactions to TRA test were registered with equal frequency and did not depend on the timing and duration of infection. A high risk factor and predictor of the disease development is high sensitization of the host to active M. tuberculosis which is found in patients with tuberculosis using TRA test six times more frequently versus Mantoux test (OR 5.951, 95% CI 3.548 and 9.981). The demonstrated results are important for the identification of children facing a high risk to develop active tuberculosis and preventive treatment prescription.

First clinical expression of equine insect bite hypersensitivity is associated with co-sensitization to multiple Culicoides allergens

Background Insect bite hypersensitivity (IBH) is an IgE-mediated allergic dermatitis in horses incited by salivary allergens from Culicoides spp. IBH does not occur in Iceland, as the causative agents are absent, however a high prevalence is seen in horses exported to Culicoides-rich environments. Aims To study the natural course of sensitization to Culicoides allergens and identify the primary sensitizing allergen(s) in horses exported from Iceland utilizing a comprehensive panel of Culicoides recombinant (r-) allergens. Method IgE microarray profiling to 27 Culicoides r-allergens was conducted on 110 serological samples from horses imported to Switzerland from Iceland that subsequently developed IBH or remained healthy. Furthermore, a longitudinal study of 31 IBH horses determined IgE profiles the summer preceding first clinical signs of IBH (TIBH-1), the summer of first clinical signs (TIBH) and the following summer (TIBH+1). In a group of Icelandic horses residing in Sweden, effects of origin (born in Iceland or Sweden) and duration of IBH (<4 years, 4–7 years, >7 years) on Culicoides-specific IgE was evaluated. Sero-positivity rates and IgE levels were compared. Results At TIBH, horses were sensitized to a median of 11 r-allergens (range = 0–21), of which nine were major allergens. This was significantly higher than TIBH-1 (3, 0–16), as well as the healthy (1, 0–14) group. There was no significant increase between TIBH and TIBH+1(12, 0–23). IBH-affected horses exported from Iceland had a significantly higher degree of sensitization than those born in Europe, while duration of IBH did not significantly affect degree of sensitization. Conclusion Significant sensitization is only detected in serum the year of first clinical signs of IBH. Horses become sensitized simultaneously to multiple Culicoides r-allergens, indicating that IgE-reactivity is due to co-sensitization rather than cross-reactivity between Culicoides allergens. Nine major first sensitizing r-allergens have been identified, which could be used for preventive allergen immunotherapy.

Effect of recrystallization on degree of sensitization in nickel free austenitic stainless steel

Purpose Effect of grain size on degree of sensitization (DOS) was been evaluated in Nickel free steel. Manganese and nitrogen contained alloy is a Ni-free austenitic stainless steels (ASS) having type 202 grade. The main purpose of this investigation is to find the effect of recrystallization on the DOS of stainless steel after the thermo-mechanical processing (cold work and thermal aging). Design/methodology/approach In the present investigation, the deformation of 202 grade analyzed using X-ray diffraction (XRD) and microstructural testing. Optical microstructure of Ni-free ASS has been done for cold worked samples with thermally aged at 900°C_6 h. Double loop electrochemical potentiodynamic reactivation test used for findings of degree of sensitization. Findings Ni-free ASS appears to be deformed more rapidly due to its higher stacking fault energy which gave results in rapid transformation from strain induced martensite to austenite in form of recrystallized grains, i.e. it concluded that as cold work percentage increases more rapidly recrystallization occurs. XRD results also indicate that more fraction of martensite formed as percentage of CW increases but as thermal aging reverted those all martensite to austenite. So investigation gives the conclusion which suggests that with high deformation at higher temperature and duration gives very less DOS. Originality/value Various literatures available for 300 series steel related to the effect of cold work on mechanical properties and sensitization mechanism. However, no one has investigated the effect of recrystallization through thermomechanical processing on the sensitization of nickel-free steel.

Friction Stir Welding: Mitigating the Susceptibility to Intergranular Corrosion of Alloy 625

In this work, friction stir welding (FSW) was employed to alloy 625 grade I (soft annealed) sheets. Therefore, solid-state based welding was undertaken with a tool rotational speed of 200 rpm and welding speed of 1 mm/s. Microstructural features were analyzed by light optical and scanning electron microscopy (SEM). Moreover, microhardness measurements were performed. The susceptibility to intergranular corrosion was verified by the double-loop electrochemical potentiokinetic reactivation (DL-EPR) test. Complementary, intergranular corrosion was evaluated by ASTM G28 Method A. FSW promoted grain refinement, increased microhardness, and reduction in the degree of sensitization. Finally, the mean corrosion rate observed in the ASTM G28A test was 0.4406 mm/year, which suggests a good weld quality.

Experiment Investigation for Design on the Sensitization-Dependent Passivation Characteristics of AL-6XN in 3.5% NaCl Solution

The sensitization and passivation characteristics of AL-6XN heat-treated for up to 24 h at 800 °C were evaluated through double loop electrochemical potentiodynamic reactivation (2 M H2SO4 + 0.01 M KSCN +2 M NaCl solution) and cyclic potentiodynamic polarization (3.5% NaCl solution) test methods. Furthermore, the dependence between the characteristic values (Epit, Erep, and degree of sensitization) was discussed. The σ phase was precipitated at the intergranular and intragranular in AL-6XN at 800 °C. When the heat treatment time exceeded 1 hour, AL-6XN occurred rapid sensitization due to the precipitation of σ phase. In a 3.5% NaCl solution, the passivation characteristics of AL-6XN with sensitivity were very poor and depended much on the degree of sensitization.

Effect of number of welding passes on the microstructure, mechanical and intergranular corrosion properties of 409M ferritic stainless steel

Purpose This paper aims to study the effect of number of welding passes on microstructure, mechanical and corrosion properties of 409 M ferritic stainless steel. Shielded metal arc welding (SMAW) process is used to weld two metal sheets of 409 M having 3 mm thickness as bead-on-plate with single, double and triple passes. Microstructures were observed at transverse section with the help of optical microscope and with increasing number of passes grain growth, and the width of heat-affected zone (HAZ) increases. The results of tensile tests revealed that as number of passes increases, there is reduction in tensile strength and ductility. Double loop electrochemical potentiokinetic reactivation (DL-EPR) test revealed that as number of passes increases, the degree of sensitization increases. This is due to the deposition of chromium carbides at the grain boundaries and the associated depletion of chromium. Design/methodology/approach Three welded plates of single, double and triple pass were welded by SMAW process. From three welded plates (single, double and triple passes), samples for microstructural examination were cut in transverse direction (perpendicular to welding direction) with the help of wire-cut electrical discharge machine (EDM). The welded plates were sliced using wire-cut EDM along transverse direction for preparing optical microscopy, tensile testing, microhardness and DL-EPR testing specimens. Findings From the microstructure, it was observed that the large grain growth, which is dendritic, and the structure become finer to increase in number of welding passes. As number of passes increases, the width of HAZ increases because of the higher temperature at the welded zone. The tensile strength decreases to increase the number of welding passes because of grain coarsening and chromium carbide precipitation in sensitized zone and wider HAZ. The maximum microhardness value was observed for single-pass weld as compared to double- and triple-pass welds because of the fast cooling rate. The degree of sensitization increases to increase the number of passes because of chromium carbide deposition at the grain boundaries. Originality/value The authors declare that the manuscript is original and not published elsewhere, and there is no conflict of interest to publish this manuscript.

Examination of Sensitization on 5xxx Series Aluminum Alloy Sheets from Structural Parts of Hellenic Navy High-Speed Craft

Al - Mg alloys are extensively used as structural materials in marine applications. Sensitization has emerged as a severe concern during the operation of aluminum vessels, due to the consequent high susceptibility to Intergranular Corrosion - IGC. Herein, a detailed study of sensitization on naturally sensitized, field retrieved, Al-Mg alloy samples, is presented. Specifically, samples from four Hellenic Navy - HN high speed vessels were tested according to ASTM G67 in order to quantify their Degree of Sensitization - DoS and qualified, in terms of grain boundaries (GBs) coverage with β phase with microstructural observation using Scanning Electron Microscopy - SEM and light optical microscopy. Consequently, the correlation of DoS value to the external factors that affect it becomes possible. Remarkably, material under investigation has significantly diverse chemical composition, compared to common marine grade aluminum alloys. Ultimately, correlation of Stress Corrosion Cracking behavior with the microstructure is discussed.

Serum artemin is not correlated with sensitivity within dogs with naturally occurring osteoarthritis pain

Osteoarthritis (OA) pain is associated with peripheral and central sensitization in humans and results in widespread increased sensitivity across the body. Sensitization contributes to the OA-associated pain (OAP) state. We recently identified increased levels of an endogenous neurotrophic factor, artemin (ARTN), in dogs with OAP compared to healthy pain-free controls. Circulating ARTN released from damaged tissues in OA, may play a central role in widespread sensitivity and pain. However, the relationship between ARTN and somatosensory sensitivity remains unknown. The study aimed to assess the relationship between serum ARTN concentrations and measures of sensitivity in dogs with OAP using quantitative sensory testing. We hypothesized that there would be a positive association between circulating ARTN and increased sensitivity to mechanical and thermal stimuli in dogs with OAP. We used linear and logistic regression models to assess the relationship between ARTN, sensitization, and pain within a cohort of 43 dogs with spontaneous OAP. Serum ARTN was not associated with the degree of sensitization within dogs with OAP. Further, across dogs with varying OAP severity, we did not find any association between ARTN, and clinical measures of joint pain and disability. Although a relationship between ARTN and joint pain was not ruled out.