Evidence for continuity of interstitial spaces across tissue and organ boundaries in humans

Bodies have continuous reticular networks, comprising collagens, elastin, glycosaminoglycans, and other extracellular matrix components, through all tissues and organs. Fibrous coverings of nerves and blood vessels create structural continuity beyond organ boundaries. We recently validated fluid flow through human fibrous tissues, though whether these interstitial spaces are continuous through the body or discontinuous, confined within individual organs, remains unclear. Here we show evidence for continuity of interstitial spaces using two approaches. Non-biological particles (tattoo pigment, colloidal silver) were tracked within colon and skin interstitial spaces and into adjacent fascia. Hyaluronic acid, a macromolecular component of interstitial spaces, was also visualized. Both techniques demonstrate interstitial continuity within and between organs including within perineurium and vascular adventitia traversing organs and the spaces between them. We suggest that there is a body-wide network of fluid-filled interstitial spaces that has significant implications for molecular signaling, cell trafficking, and the spread of malignant and infectious disease.

Id reaction and allergic contact dermatitis post-picosecond laser tattoo removal: A case report

The novel picosecond lasers have emerged as a mainstay device in laser tattoo removal alongside Q-switch lasers, considered the gold standard in the field. Here, we present a 45-year-old female who developed a severe reaction to both her treated and untreated tattoos after two picosecond laser treatments and subsequent widespread eczematous eruption. Skin biopsies revealed findings consistent with hypersensitivity to exogenous red pigment. The clinicopathologic findings were consistent with an id reaction (autoeczematization) associated with allergic contact dermatitis to tattoo pigment. This case report highlights the potential for tattoo hypersensitivity following picosecond laser treatment and the dilemma associated with tattoo removal in sensitized patients. Additional therapeutic approaches are needed to provide patients with a safe means of tattoo removal while mitigating the risk of hypersensitivity reactions.

Mycobacterium Kansasii Infection Overlying Tattoo Pigment in an Immunocompromised Patient

The incidence of atypical mycobacterial infections has steadily grown over the past decades, and it is well-known that the risk of progressive disease increases with immunodeficiency. While rare, tattoo pigment can serve as a nidus for atypical mycobacterium infection in immunocompromised individuals. Here, we present a case of a 41-year-old immunocompromised female who presented with verrucous plaques overlying long-standing tattoos in multiple locations. The patient’s lesions were biopsied and sent for board-range polymerase chain reaction revealing infection with Mycobacterium kansasii, a slow-growing atypical mycobacterium that rarely causes cutaneous disease without systemic symptoms. Early recognition and treatment of cutaneous M. kansasii is important to prevent progression of disease.

Optimization of laser technology for removing tatuage pigment

Purpose: To study the effectiveness of tattoo pigment removal with laser light depending on the wavelength and depth of penetration into tissues in order to optimize a technique of laser selective photocavitation. Material and methods. 127 male white mongrel rats, aged 8 weeks, were intradermally injected with pigment particles into their backs looking like 2 rows of spots 0.5 cm in diameter. In 6 weeks, 367 skin samples with tattoo pigment were taken. Each sample was a patch of epidermis with pigment crystals surrounded by connective tissue capsules not less than 2.5 mm of thickness. Before the experiment, the epidermal stratum corneum – 10–15 mkm in depth and about 1 mm in diameter- was removed with spray-coagulation (apparatus EHVCH-50-MEDSI). The rest of skin flap surface remained intact. Thus, each skin sample had two areas on the surface – one with removed stratum corneum (experimental) and the other one intact (control). To register changes in the luminous flux, the authors placed an emitter (IPL xenon lamp 7.65.130), tissue sample and photomultiplier (PMT-62) on one and the same axis. To cut off light waves, the authors used a set of light filters – 315, 364, 400, 440, 490, 540, 590, 670, 750, 870, 980 nm. Results. Destruction of skin surface layers was not statistically significant under wavelengths up to 450 nm and after 1000 nm. The epidermal stratum corneum prevents laser light penetration with wavelengths 450–694 nm by 27%, in average, and with wavelengths 700–1000 nm by 33%, in average. Conclusion. Epidermal stratum corneum destruction statistically significantly increases light density in deep tissue layers and increases the depth of penetration of laser light into biological tissues.

Interstitial spaces are continuous across tissue and organ boundaries in humans

Bodies have “reticular networks” comprising collagens, elastin, glycosaminoglycans, and other extracellular matrix components, that are continuous within and around all organs. Fibrous tissue coverings of nerves and blood vessels create structural continuity beyond organ boundaries. We recently described fluid flow through such human fibrous tissues. It remains unclear whether these interstitial spaces are continuous through the body or are discontinuous, confined within individual organs. We investigated IS continuity using two approaches. Non-biological particles (tattoo pigment, colloidal silver) were tracked within colon and skin interstitial spaces and into adjacent fascia. We also exploited hyaluronic acid, a macromolecular component of interstitial spaces. Both techniques demonstrate continuity of interstitial spaces within and across organ boundaries, including within perineurium and vascular adventitia traversing organs and the spaces between them. We suggest a body-wide network of fluid-filled interstitial spaces with significant implications for molecular signaling, cell trafficking, and the spread of malignant and infectious disease.