Wound healing in the context of "Cell proliferation"

Injury is physiological damage to the living tissue of any organism, whether in humans, in other animals, or in plants.

Injuries can be caused in many ways, including mechanically with penetration by sharp objects such as teeth or with blunt objects, by heat or cold, or by venoms and biotoxins. Injury prompts an inflammatory response in many taxa of animals; this prompts wound healing. In both plants and animals, substances are often released to help to occlude the wound, limiting loss of fluids and the entry of pathogens such as bacteria. Many organisms secrete antimicrobial chemicals which limit wound infection; in addition, animals have a variety of immune responses for the same purpose. Both plants and animals have regrowth mechanisms which may result in complete or partial healing over the injury. Cells too can repair damage to a certain degree.

Smallpox was an infectious disease caused by Variola virus (often called Smallpox virus), which belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) certified the global eradication of the disease in 1980, making smallpox the only human disease to have been eradicated to date.

The initial symptoms of the disease included fever and vomiting. This was followed by formation of ulcers in the mouth and a skin rash. Over a number of days, the skin rash turned into the characteristic fluid-filled blisters with a dent in the center. The bumps then scabbed over and fell off, leaving scars. The disease was transmitted from one person to another primarily through prolonged face-to-face contact with an infected person or rarely via contaminated objects. Prevention was achieved mainly through the smallpox vaccine. Once the disease had developed, certain antiviral medications could potentially have helped, but such medications did not become available until after the disease was eradicated. The risk of death was about 30%, with higher rates among babies. Often, those who survived had extensive scarring of their skin, and some were left blind.

Skin care or skincare is the practice of maintaining and improving the health and appearance of the skin. It includes washing, moisturizing, protecting from the sun, and treating skin problems like acne and dryness. Skin care can help prevent infections and irritation and is an important part of daily hygiene.

Skin care is at the interface of cosmetics and dermatology. Skin care differs from dermatology by its inclusion of non-physician professionals, such as estheticians and nursing staff. Skin care includes modifications of individual behavior and of environmental and working conditions. Skin care is an essential part of wound healing, radiation therapy, and the management of some medications.

Injury in animals is damage to the body caused by wounding, change in pressure, heat or cold, chemical substances, venoms and biotoxins. Injury prompts an inflammatory response in many taxa of animals; this prompts wound healing, which may be rapid, as in the Cnidaria.

Peyronie's disease (PD) is a benign, acquired penile connective tissue disease characterized by the occurrence of fibrotic plaques within the tunica albuginea — the dense elastic covering of the corpora cavernosa. The plaques cause abnormal curvature, pain, penile deformities (e.g., narrowing or indentation), and usually erectile dysfunction, particularly during erection. The condition typically leads to significant sexual and psychological effects, including difficulty with penetration and lowered self-esteem or evasiveness. Peyronie's disease is most often seen in middle-aged and older men with a median age of onset between 55 and 60 years, however it is also common in younger individuals and adolescents.

While the etiology of Peyronie's disease is still uncertain, the leading hypothesis is that it arises from dysregulated wound healing in response to chronic microtrauma of the erect penis. This triggers a cascade of profibrotic molecular pathways — most notably overexpression of transforming growth factor-beta 1 (TGF-β1) — that end in fibroblast proliferation, myofibroblast differentiation, and overproduction of type I collagen. Genetic predisposition is supported by family clustering and linkage with systemic fibrosing disorders such as Dupuytren's contracture. Risk factors include age, penile injury, diabetes mellitus, and cigarette smoking.

Scarification involves scratching, etching, burning/branding, or superficially cutting designs, pictures, or words into the skin as a permanent body modification or body art. The body modification can take roughly 6–12 months to heal. In the process of body scarification, scars are purposely formed by cutting or branding the skin by various methods (sometimes using further sequential aggravating wound-healing methods at timed intervals, like irritation). Scarification is sometimes called cicatrization.

The regulatory T cells (Tregs /ˈtiːrɛɡ/ or T_reg cells), formerly known as suppressor T cells, are a subpopulation of T cells that modulate the immune system, maintain tolerance to self-antigens, and prevent autoimmune disease. T_reg cells are immunosuppressive and generally suppress or downregulate induction and proliferation of effector T cells. T_reg cells express the biomarkers CD4, FOXP3, and CD25 and are thought to be derived from the same lineage as naïve CD4 cells. Because effector T cells also express CD4 and CD25, T_reg cells are very difficult to effectively discern from effector CD4, making them difficult to study. Research has found that the cytokine transforming growth factor beta (TGF-β) is essential for T_reg cells to differentiate from naïve CD4 cells and is important in maintaining T_reg cell homeostasis.

Mouse models have suggested that modulation of T_reg cells can treat autoimmune disease and cancer and can facilitate organ transplantation and wound healing. Their implications for cancer are complicated. T_reg cells tend to be upregulated in individuals with cancer, and they seem to be recruited to the site of many tumors. Studies in both humans and animal models have implicated that high numbers of T_reg cells in the tumor microenvironment is indicative of a poor prognosis, and T_reg cells are thought to suppress tumor immunity, thus hindering the body's innate ability to control the growth of cancerous cells. Immunotherapy research is studying how regulation of T cells could possibly be utilized in the treatment of cancer.