High histamine concentrations in human sweat in association with type I allergy to the semi-purified sweat antigen

Humanoid shaped optical fiber plasmon biosensor functionalized with graphene oxide/multi-walled carbon nanotubes for histamine detection

Histamine is a biologically active molecule that serves as a reliable predictor of the quality of fish. In this work, authors have developed a novel humanoid-shaped tapered optical fiber (HTOF) biosensor based on the localized surface plasmon resonance (LSPR) phenomenon to detect varying histamine concentrations. In this experiment, a novel and distinctive tapering structure has been developed using a combiner manufacturing system and contemporary processing technologies. Graphene oxide (GO)/multi-walled carbon nanotubes (MWCNTs) are immobilized on the HTOF probe surface to increase the biocompatibility of biosensor. In this instance, GO/MWCNTs are deployed first, then gold nanoparticles (AuNPs). Consequently, the GO/MWCNTs help to give abundant space for the immobilization of nanoparticles (AuNPs in this case) as well as increase surface area for the attachment of biomolecules to the fiber surface. By immobilizing AuNPs on the surface of the probe, the evanescent field can stimulate the AuNPs and excite the LSPR phenomena for sensing the histamine. The surface of the sensing probe is functionalized with diamine oxidase enzyme in order to enhance the histamine sensor's particular selectivity. The proposed sensor is demonstrated experimentally to have a sensitivity of 5.5 nm/mM and a detection limit of 59.45 µM in the linear detection range of 0-1000 µM. In addition, the probe's reusability, reproducibility, stability, and selectivity are tested; the results of these indices show that the probe has a high application potential for detecting histamine levels in marine products.

In situ engineering of Au-Ag alloy embedded PEDOT nanohybrids at a solvent/non-solvent interface for the electrochemical enzyme-free detection of histamine

Steadfast efforts have been made to develop novel materials and incorporate them into functional devices for practical applications, pushing the research on electroactive materials to the forefront of nano electronics. Liquid/liquid interface-assisted polymerization offers a scalable methodology to fabricate hybrid materials with multifunctional applications, in contrast to the conventional and ubiquitous routes. Here, we explored this efficient and versatile approach toward the in situ tailoring of Au-Ag alloy nanostructures with a conducting polymer, poly(3,4-ethylene-dioxythiophene) (PEDOT). With the appropriate choice of organic and inorganic phases for the distribution of monomer and oxidant, the miscibility restraints of the reactants in a single phase were alleviated. Effective nanostructure tuning of highly crystalline and electroactive PEDOT/Au-Ag alloy has been achieved by varying the molar ratio of Au³⁺/Ag⁺ in the reaction mixture. The as-synthesized composite is further explored to detect neuromodulator histamine (HA), which displays high sensitivity with a limit of detection (LOD) of 1.5 nM, and selectivity even in the presence of various interfering analogs of 10-fold concentration. Subsequently, density functional theory (DFT) simulations are employed to assess the mode of interaction between HA and the electroactive surfaces. The competency to detect HA in preserved food entails its potential in food spoilage monitoring. Furthermore, the detection of histamine generated by sub-cultured human neuronal cells SH-SY5Y proves its practical viability in health monitoring devices.

Anhidrosis accompanied by cholinergic urticaria-like rash and dermal pain in a patient with Sjögren's syndrome

Cholinergic urticaria (CholU)-like rash and dermal pain on sweating occur in patients with acquired idiopathic generalized anhidrosis (AIGA). However, it is unclear whether these are symptoms specific to AIGA among the various types of acquired generalized anhidrosis/hypohidrosis (AGAH). Moreover, the pathogenesis underlying CholU-like rash and dermal pain observed with anhidrosis remains to be clarified. A 20-year-old Japanese man with Sjögren's syndrome (SS) presented with anhidrosis. Transient stinging pain on the skin and pinpoint wheals were observed when his body temperature increased. Thermoregulatory sweat testing revealed anhidrotic areas covering 69% of the body surface area with a symmetrical distribution. A high concentration of histamine was detected (506 ng/mL) in the sweat. A skin biopsy specimen from the anhidrotic area showed the inflamed secretory portion of eccrine glands. This suggested inflammation-mediated damage to sweat glands, consistent with AGAH related to SS. Furthermore, immunohistochemical analysis revealed an ectopic distribution of dermcidin, a sweat-specific peptide, in the dermal tissue surrounding the secretory portion of eccrine glands. The expression of claudin-3, a tight junction (TJ) component of sweat glands, decreased or distributed in a mottled manner in the secretory portion. No decreased expression of muscarinic cholinergic receptor M3 was detected. These results suggested that sweat had leaked into the dermis in association with impaired TJ in the secretory portion, along with the damage to inflamed sweat glands related to SS. Collectively, CholU-like rash and dermal pain on sweating were observed in an AGAH patient with SS. The sweat leakage into the dermis may contribute to the development of the rash and pain.

Clinical and histological characterization of transient dermal pain triggered by sweating stimuli

BACKGROUND

Tingling dermal pain triggered by sweating impairs the lives of patients with cholinergic urticaria and generalized anhidrosis. However, dermal pain evoked by sweating stimuli has been under investigated.

METHODS

To clarify characteristics of tingling dermal pain on sweating, we retrospectively evaluated clinical and histopathological manifestations in 30 patients having the main problem of dermal pain on sweating, and the efficacy of treatments.

RESULTS

Dermal pain upon sweating affected mostly young males. It accompanied eruptions upon sweating and/or hypohidrosis in 24 patients, while 6 patients had dermal pain independently of hypohidrosis or eruptions. Dermal pain appeared immediately upon exposure to sweating stimuli, and disappeared within mostly 30 or 10 min. Hypohidrosis was not necessarily generalized but localized or absent. Histological analysis revealed that dermal pain could occur even without morphological changes and inflammation of sweat glands. Hypersensitivity to sweat contents was found only in 26% of patients. Sweat histamine and increase of plasma histamine after thermal induction in patients were significantly higher than those in healthy subjects. Effectiveness of steroid pulse therapy was demonstrated for dermal pain with hypohidrosis. Medications acting on nervous systems and regular sweat-inducing activities for promoting perspiration were also effective.

CONCLUSIONS

Short-lasting tingling dermal pain appears immediately upon exposure to sweating stimuli, regardless of developing eruptions and/or presence of hypohidrosis, but possibly in association with sweat and plasma histamine.