OBJECTIVES: To investigate the protective effects of graphene heating film far-infrared (FIR) hyperthermia therapy against frostbite in mice and its impacts on microcirculation and coagulation function. METHODS: Seventy-six C57BL/6J mice were randomized into control, model, graphene-FIR, and carbon fiber-FIR groups. After 7-day FIR intervention (4 h/day), the mice were subjected to acute (4 ℃, 4 h) and intermittent (4 ℃, 4 h/day for 3 days) cold exposure and the changes in rectal temperature were monitored. In liquid nitrogen frostbite experiment, 24 ICR mice were divided into model, graphene-FIR, and carbon fiber-FIR groups, and after a 7-day FIR pretreatment (4 h/day), the liquid nitrogen frostbite models were established and apparent scores of the wounds were assessed on days 3 and 6 after modeling. In carrageenan-induced thrombosis experiment, 40 ICR mice were allocated to control, model, graphene-FIR, carbon fiber-FIR, and prazosin groups to test the effect of a 7-day FIR intervention on thrombosis induced by intraperitoneal carrageenan injection (2.5 mg/kg) by measuring thrombus length, blood perfusion, and serum biomarkers (6-keto-PGF1α, TXB2, t-PA, IL-6, IL-1β, TNF‑α) 24 h after the injection. RESULTS: The mice in graphene-FIR group showed significantly elevated rectal temperature in cold exposure tests. In mice with liquid nitrogen-induced frostbite, graphene-FIR treatment significantly reduced the wound scores and reduced frostbite area, producing better effects than carbon fiber. In mice with carrageenan-induced thrombosis, graphene-FIR treatment significantly decreased tail thrombosis length and thrombosis area, increased blood perfusion, lowered serum levels of TXB2, TNF-α and IL-6, and increased the levels of 6-keto-PGF1α and t-PA. CONCLUSIONS Graphene heating film FIR therapy can alleviate frostbite injury in mice by improving microcirculation, suppressing thrombosis and inflammatory responses, and reducing coagulation dysfunction.
Animals ; Frostbite/therapy* ; Graphite ; Mice, Inbred C57BL ; Mice ; Infrared Rays ; Mice, Inbred ICR ; Hyperthermia, Induced/methods* ; Male ; Microcirculation

Frostbite is the most common cold injury and is caused by both immediate cold-induced cell death and the gradual development of localized inflammation and tissue ischemia. Delayed healing of frostbite often leads to scar formation, which not only causes psychological distress but also tends to result in the development of secondary malignant tumors. Therefore, a rapid healing method for frostbite wounds is urgently needed. Herein, we used a mouse skin model of frostbite injury to evaluate the recovery process after frostbite. Moreover, single-cell transcriptomics was used to determine the patterns of changes in monocytes, macrophages, epidermal cells, and fibroblasts during frostbite. Most importantly, human-induced pluripotent stem cell (hiPSC)-derived skin organoids combined with gelatin-hydrogel were constructed for the treatment of frostbite. The results showed that skin organoid treatment significantly accelerated wound healing by reducing early inflammation after frostbite and increasing the proportions of epidermal stem cells. Moreover, in the later stage of wound healing, skin organoids reduced the overall proportions of fibroblasts, significantly reduced fibroblast-to-myofibroblast transition by regulating the integrin α5β1-FAK pathway, and remodeled the extracellular matrix (ECM) through degradation and reassembly mechanisms, facilitating the restoration of physiological ECM and reducing the abundance of ECM associated with abnormal scar formation. These results highlight the potential application of organoids for promoting the reversal of frostbite-related injury and the recovery of skin functions. This study provides a new therapeutic alternative for patients suffering from disfigurement and skin dysfunction caused by frostbite.
Animals ; Organoids/metabolism* ; Mice ; Humans ; Wound Healing ; Frostbite/metabolism* ; Skin/pathology* ; Induced Pluripotent Stem Cells/cytology* ; Cicatrix/pathology* ; Fibroblasts/metabolism* ; Disease Models, Animal ; Mice, Inbred C57BL ; Extracellular Matrix/metabolism* ; Male

Huangqi Guizhi Wuwu Decoction is a classic prescription in traditional Chinese medicine(TCM) and is known for its effects of tonifying Qi, warming the meridians, and promoting blood circulation to alleviate obstruction. It is primarily used to treat conditions characterized by Qi stagnation, Yang deficiency, and obstruction, and it exhibits pharmacological effects such as immune regulation, anti-inflammation, analgesia, protection of the cardiovascular and cerebrovascular systems, itch relief, reduction of frostbite symptoms, antioxidative stress, promotion of cell apoptosis, and kidney protection. In modern clinical practice, it is commonly used to treat acute myocardial infarction, sequelae of cerebral infarction, cervical spondylosis, frozen shoulder, lower limb arteriosclerosis, lower limb vascular disorders, peripheral neuropathy in diabetes, and lupus nephritis. Recent research has focused on the chemical components, pharmacological effects, and clinical applications of Huangqi Guizhi Wuwu Decoction. Based on the "five principles" of quality markers(Q-markers) in TCM, this study predicted and analyzed the Q-markers of Huangqi Guizhi Wuwu Decoction. It suggested that astragaloside Ⅳ, formononetin, kaempferol, quercetin, cinnamic acid, cinnamaldehyde, 6-gingerol, paeoniflorin, albiflorin, and gallic acid could serve as Q-markers for Huangqi Guizhi Wuwu Decoction. The findings of this study can provide references for quality control of Huangqi Guizhi Wuwu Decoction and the development of new Chinese medicinal formulations.
Drugs, Chinese Herbal/therapeutic use* ; Medicine, Chinese Traditional ; Astragalus propinquus ; Frostbite/drug therapy*

Frostbite in Southwestern China has been overlooked due to its low incidence, relatively mild temperature and lack of literature published before. However, it needs to be further studied for religious diversity and distinct geomorphology. In this article, we reported an 18-year-old Tibetan girl who suffered from blizzard attack during pilgrimage. Her feet and several fingers showed mummified gangrene upon physical examination with poor movement. She was diagnosed with 3rd to 4th degree of frostbite. The girl was given oral ibuprofen, debridement and other regular treatment daily, but she was eventually amputated due to insufficient thrombolytic management in primary hospital, delayed informing consent in the referral hospital and ethnic conflict between religion and guidelines. This case enriched the experience of managing complex frostbite in Tibetan population and alarms that efforts should be integrated to protect pilgrims and mountaineers in the Tibetan region.
Adolescent ; Amputation ; China ; Female ; Frostbite/therapy* ; Humans ; Incidence ; Tibet

The human capacity for physiologic adaptation to cold is minimal. A cold environment can be a threat to the skin, leading to a subsequent fall in core body temperature. Many physiologic, behavioral, and environmental factors predispose to the global effects of cold injuries. Physical injuries caused by cold have two forms: systemic forms such as hypothermia and localized forms such as frostbite. Reduced temperature directly damages the tissue, as in frostbite and cold immersion foot. Vasospasm of vessels perfusing the skin induces chilblain, acrocyanosis, and frostbite. The degree of damage caused by cold is related to four factors: temperature, exposure time, wind intensity (temperature sensation), and high altitude.
Adaptation, Physiological ; Altitude ; Body Temperature ; Chilblains ; Cold Injury ; Frostbite ; Humans ; Hypothermia ; Immersion Foot ; Skin ; Wind

Frostbite is a common disease in winter, and systemic or local injury caused by low temperature invasion. Frostbite sites are commonly face, ears, nose, hands, feet and other peripheral blood circulation parts. The main symptoms are pale skin, cold, pain and numbness, skin itching in high temperature, and severe cases may suffer from skin erosions and ulcers. Frostbite model is a pathological model mainly based on Western medicine index. Based on the analysis of clinical symptoms of frostbite in traditional Chinese medicine and western medicine, and a large number of experimental studies on the existing animal models, the animal model preparation of specifications (draft) was formulated as follows.
Animals ; Cold Temperature ; Frostbite ; Models, Animal

OBJECTIVETo study the key points of treatment and amputation in patients with frostbite, so as to increase the successful rate of the treatment.

METHODSFive hundred and sixty-eight patients with frostbite admitted to our department from January 2005 to December 2014. (1) For the patients admitted to our department within one week after injury, the frostbite wounds were soaked in 42 °C herbal fluid (twice per day, 30 min for each time) and irradiated with infrared or red light (three times per day, 40 min for each time) from the day of admission to the 7th day after injury. Meanwhile, treatment for improvement of microcirculation, vasodilation, and anti-infection were also given. Then they received infrared or red light irradiation to the wound sites. For the patients admitted to our department longer than one week after frostbite, the frostbite wounds were irradiated with infrared or red light, and treated with antibiotics if inflammation was found around the wound. Among all the patients, 5 cases suffered from frozen stiff, and they were given fluid resuscitation as well as above-mentioned treatments after admission. (2) All patients were given wound treatment immediately after admission. The superficial partial-thickness wounds and deep partial-thickness wounds of 264 patients were given routine dressing change. The full-thickness wounds in 79 patients were treated with exposure therapy after routine dressing change first, and then granulation tissue of these wounds were grafted with autologous thigh split-thickness skin grafts. After debridement and exposure therapy, amputation was done in 225 patients 3 to 4 weeks after injury when the underlying bone was exposed. In 4 patients with exposure of calcaneus, the wounds were covered with reverse sural nerve nutrient vessels island flap. Mean healing time of superficial partial-thickness wound and deep partial-thickness wound, survival rate of skin graft in full-thickness wound, and survival rate of flap covering wound deep to bone at the heel were all recorded. The amputation rate of patients injured in December, January, February, and other months, that of patients admitted shorter than 1 day after frostbite, 1 to 3 days after frostbite, longer than 3 days and shorter than or equal to 5 days after frostbite, and longer than 5 days after frostbite, that of patients caused by drunkenness, mental disorders, improper protection, going astray, and trauma including traffic accident etc., and that of patients treated with rewarming under room temperature, rubbing with snow, wrapping with quilt, and soaking in warm water before admission were all recorded and analyzed. Parts of the data were processed with χ(2) test.

RESULTSAll patients were survived after treatment. Average wound healing time of superficial partial -thickness wound and deep partial-thickness wound was respectively 10 and 23 days. The survival rate of skin graft on full-thickness wound was about 95%. Survival rate of flap on wound deep to bone at the heel was 100%. Amputation rates of patients injured in December and January were respectively 47.46% (84/177), 42.56% (103/242), and both were significantly higher than those of patients injured in February and the other months [respectively 29.55% (26/88), 13.11% (8/61), with χ(2) values from 42.595 to 220.900, P values below 0.01]. Amputation rate of patients with admission time shorter than 1 day after frostbite was 32.06% (84/262), which was obviously lower than that of patients with admission time from 1 to 3 days after frostbite, longer than 3 days and less than or equal to 5 days after frostbite, or longer than 5 days after frostbite [respectively 40.48% (68/168), 49.02% (50/102), 52.78% (19/36), with χ(2) values from 107.284 to 165.350, P values below 0.01]. Amputation rates of patients with frostbite occurring after getting drunkenness, mental disorders, and trauma including traffic accident etc. were respectively 42.06% (106/252), 43.48% (60/138), and 53.12% (17/32), and they were all significantly higher than those of patients with frostbite caused by improper protection and going astray [respectively 27.45% (28/102), 22.73% (10/44), with χ(2) values from 187.260 to 209.738, P values below 0.01]. Amputation rates of patients undergoing treatment of rewarming under room temperature, rubbing with snow, wrapping with quilt before admission were respectively 44.29% (62/140), 48.28% (84/174), and 35.38% (46/130), and they were significantly higher than the amputation rate of patients who received the treatment of soaking in warm water [23.39% (29/124), with χ(2) values from 97.364 to 136.189, P values below 0.01].

CONCLUSIONSEarly diagnosis and treatment, properly rewarming at early stage, and correct wound treatment are the key points for reducing amputation rate of patients after frostbite. Attention should be paid to the occurrence of frostbite in December and January, and also to protection of high-risk groups (patients with mental disorders and drunker).

Amputation ; statistics & numerical data ; China ; Debridement ; Frostbite ; pathology ; therapy ; Granulation Tissue ; Humans ; Microcirculation ; Negative-Pressure Wound Therapy ; Skin ; blood supply ; Skin Transplantation ; methods ; Surgical Flaps ; Treatment Outcome ; Wound Healing

Squamous cell carcinoma commonly originates from recalcitrant wound sites, including burn scars, pressure sores, stasis ulcers, osteomyelitis, and sites of frostbite. A 62-year-old male was referred to the dermatology department for skin necrosis of his right great toe and walking difficulty. He had a history of smoking, drinking alcohol, and frostbite of his right great toe 9 years prior, which deteriorated into osteomyelitis due to poor care. Although a skin biopsy was recommended before amputation, the two procedures were performed simultaneously due to a lack of toe function due to severe osteolysis. Biopsy of the amputated toe tip showed many lobules consisting of atypical keratinocytes with hyperchromatic nuclei, and severe dermal pleomorphism. After evaluation for distant metastasis, including a (99m) Tc-MDP bone scan, 18F-FDG positron emission tomography scan, computed tomography, and ultrasound, no metastasis was detected.
Amputation ; Biopsy ; Burns ; Carcinoma, Squamous Cell* ; Cicatrix ; Dermatology ; Drinking ; Fluorodeoxyglucose F18 ; Frostbite ; Humans ; Keratinocytes ; Male ; Middle Aged ; Necrosis ; Neoplasm Metastasis ; Osteolysis ; Osteomyelitis* ; Positron-Emission Tomography ; Pressure Ulcer ; Skin ; Smoke ; Smoking ; Toes ; Ultrasonography ; Varicose Ulcer ; Walking ; Wounds and Injuries

The objective of this study was to prepare nanostructured lipid carrier (NLC)-based topical gel of Ganoderma Triterpenoids (GTs) and evaluate their effects on frostbite treatment. GT-NLCs was prepared by the high pressure homogenization method and then characterized by morphology and analyses of particle size, zeta potential, entrapment efficiency (EE), and drug loading (DL). The NLCs was suitably gelled for skin permeation studies in vitro and pharmacodynamic evaluation in vivo, compared with the GT emulgel. The GT-NLC remained within the colloidal range and was uniformly dispersed after suitably gelled by carbopol preparation. Transmission electron microscopy (TEM) study showed GT-NLCs was spherical in shape. The EE (%) and DL (%) could reach up to (81.84 ± 0.60)% and (2.13 ± 0.12)%, respectively. The result of X-ray diffractograms (XRD) showed that GTs were in an amorphous state in the NLC-gel. In vitro permeation studies through rat skin indicated that the amount of GTs permeated through skin of GT-NLCs after 24 h was higher than that of GT emulsion, and GT-NLCs increased the accumulative amounts of GTs in epidermis 7.76 times greater than GT emulsion. GT-NLC-gel was found to possess superior therapeutic effect for frostbite, compared with the GT emulgel. The NLC based topical gel of GTs could improve -their therapeutic effect for frostbite.
Animals ; Drug Carriers ; chemistry ; Drugs, Chinese Herbal ; administration & dosage ; chemistry ; Frostbite ; drug therapy ; Ganoderma ; chemistry ; Gels ; administration & dosage ; chemistry ; Humans ; Lipids ; chemistry ; Male ; Nanostructures ; administration & dosage ; chemistry ; Rats ; Rats, Sprague-Dawley

BACKGROUND: This paper discusses the treatment protocol for patients with frostbite. METHODS: We performed a retrospective analysis of a series of 17 patients with second- and higher-degree frostbite who had been treated at our medical institution between 2010 and 2012. RESULTS: Our clinical series of patients (n=17) included 13 men and four women, whose mean age was 42.4+/-11.6 years (range, 22-67 years). The sites of injury include the foot in six patients (35.3%), the hand in six patients (35.3%) and the facial region in five patients (29.4%). Seven patients with second-degree frostbite were completely cured with only conservative treatment during a mean period of 12.7+/-3.3 days (range, 8-16 days). Of the five patients with third-degree frostbite, two underwent skin grafting following debridement, and the remaining three achieved a complete cure with conservative treatment during a mean period of 35+/-4.3 days (range, 29-39 days). Five patients with fourth-degree frostbite were treated with surgical procedures including amputation. CONCLUSIONS: With the appropriate conservative management in the early stage of onset, surgeons should decide on surgery after waiting for a sufficient period of time until the demarcation of the wound. Continuous management of patients is also needed to achieve functional recovery after a complete cure has been achieved. This should also be accompanied by patient education for the avoidance of re-exposure to cold environments.
Clinical Protocols ; Cold Temperature ; Debridement ; Female ; Foot ; Frostbite ; Hand ; Humans ; Male ; Patient Education as Topic ; Retrospective Studies ; Skin Transplantation ; Surgical Procedures, Operative