Female child with hematidrosis of the palm: Case report and published work review.

Hematidrosis is a rare disorder involving spontaneous excretion of sweat contaminated by blood cells. We report the case of a 6-year-old girl with hematidrosis from her palms with no underlying disease or psychotic disorder. Before the onset of this symptom, the patient was given an indoor horizontal exercise bar with which she had been frequently playing. This symptom appeared without apparent triggers and was not associated with subjective symptoms. To examine her hematidrosis, metabolites in the red bodily fluid were analyzed using nuclear magnetic resonance analysis. We found the fluid had a metabolome profile similar to that of eccrine sweat. Pathological analysis revealed no abnormal findings, including expression of the tight junction protein claudin 3. Her symptom decreased after treatment with tap-water iontophoresis. Here, we describe our case and discuss its etiology by reviewing previous reports.

Proteomic Profiling of Sweat Exosome Suggests its Involvement in Skin Immunity.

Healthy human skin sustains an effective immune defense mechanism, formed by a complex physical and chemical epidermal barrier that coordinates with different cellular components of the skin immune system. However, the mechanism by which skin cells regulate local immune homeostasis in health and disease contexts is not well known. To investigate whether exosomes exist in sweat, sweat samples from healthy individuals were collected after aerobic exercise. Sweat exosome was isolated via differential ultracentrifugation, observed under transmission electron microscopy, measured by dynamic light scattering, and confirmed by immunoblot. Further, shotgun liquid chromatography (LC)-mass spectrometry (MS)/MS analysis was conducted to investigate the proteomic profiling of sweat exosome. Secreted exosome was detected in human sweat. A total of 1,062 proteins were identified in sweat exosome, including 997 different proteins compared with sweat proteomics and 896 unique proteins compared with urine, saliva, and plasma exosomes. Diverse antimicrobial peptides and immunological factors were found in sweat exosome, suggesting the involvement of exosome in skin immunity. This study provides direct evidence that secreted exosomes exist in human sweat. The proteomic profiling of sweat exosome provides insight into sweat features and the potential physiological significance of exosomes in immune homeostasis.

Combined in vivo confocal Raman spectroscopy and confocal microscopy of human skin.

In vivo confocal Raman spectroscopy is a noninvasive optical method to obtain detailed information about the molecular composition of the skin with high spatial resolution. In vivo confocal scanning laser microscopy is an imaging modality that provides optical sections of the skin without physically dissecting the tissue. A combination of both techniques in a single instrument is described. This combination allows the skin morphology to be visualized and (subsurface) structures in the skin to be targeted for Raman measurements. Novel results are presented that show detailed in vivo concentration profiles of water and of natural moisturizing factor for the stratum corneum that are directly related to the skin architecture by in vivo cross-sectional images of the skin. Targeting of skin structures is demonstrated by recording in vivo Raman spectra of sweat ducts and sebaceous glands in situ. In vivo measurements on dermal capillaries yielded high-quality Raman spectra of blood in a completely noninvasive manner. From the results of this exploratory study we conclude that the technique presented has great potential for fundamental skin research, pharmacology (percutaneous transport), clinical dermatology, and cosmetic research, as well as for noninvasive analysis of blood analytes, including glucose.

Thiol-dependent aminopeptidase (350,000 mol wt) as a marker of epidermal contamination in sweat.

L-Leucine 2-naphthylamide (Leu-NA) hydrolytic activity is increased 20-fold in eccrine sweat collected by simple scraping (SS) compared with sweat collected over the white petrolatum (Vaseline) barrier (clean sweat, CS) [Am. J. Physiol. 250 (Regulatory Integrative Comp. Physiol. 19): R691-R698, 1986]. Sephadex G-200 chromatography of SS but not that of CS showed a single peak of Leu-NA hydrolytic activity (at pH 8) at 350,000 mol wt. An enzyme with similar molecular weight was eluted from tape-stripped stratum corneum and from stripped skin in situ. Anion-exchange FPLC of the 350,000 fractions yielded a single Leu-NA hydrolase peak at pH 8 (pool IV), which also showed hydrolytic activity for benzoyl-L-arginine-2-naphthylamide (BANA). Both Leu-NA and BANA hydrolytic activities of pool IV were thiol dependent, inhibited by heavy metals, and activated by ethylenediaminetetraacetic acid. The pool IV enzyme also hydrolyzed L-lysine- and L-arginine-2-naphthylamide. The most prominent BANA hydrolase activity was seen in both SS and CS at pH 5.0 at 33,000, which was not associated with Leu-NA hydrolytic activity. Diethylaminoethyl cellulose chromatography of the 33,000 fractions yielded three peaks of BANA hydrolytic activity in SS but only one in CS, suggesting that this thiol-dependent BANA hydrolyzing enzyme in CS may be of sweat gland origin. We conclude that the 350,000 thiol-dependent Leu-NA-hydrolyzing aminopeptidase is one of the most prominent epidermal contaminants and thus is a useful marker of epidermal contamination in sweat samples.