Review

Authors: Shirish Dubey, Nilay Joshi, Olivia Stevenson...

Chilblains were first described over a hundred years ago as cutaneous inflammatory lesions, typically on the digits, occurring on cold exposure. Chilblains can be primary, or secondary to a number of conditions such as infections, including COVID-19, and immune-mediated inflammatory disorders (IMIDs) with SLE being the commonest. Chilblain lupus erythematosus (CHLE) was first described in 1888 as cold-induced erythematous lesions before the terms 'chilblains' or 'perniosis' were coined. Diagnostic criteria exist for both chilblains and CHLE. Histopathologically, CHLE lesions show interface dermatitis with perivascular lymphocytic infiltrate. Immunofluorescence demonstrates linear deposits of immunoglobulins and complement in the dermo-epidermal junction. This narrative review focuses on chilblains secondary to immune-mediated inflammatory disorders, primarily the epidemiology, pathogenesis and treatment of CHLE.

Topics: Humans; Chilblains; COVID-19; Lupus Erythematosus, Discoid; Dermatitis; Diagnosis, Differential; Lupus Erythematosus, Cutaneous

PubMed: 35412601
DOI: 10.1093/rheumatology/keac231

Comparative Study

Authors: David Hardy, Aurore Besnard, Mathilde Latil...

BACKGROUND

A longstanding goal in regenerative medicine is to reconstitute functional tissues or organs after injury or disease. Attention has focused on the identification and relative contribution of tissue specific stem cells to the regeneration process. Relatively little is known about how the physiological process is regulated by other tissue constituents. Numerous injury models are used to investigate tissue regeneration, however, these models are often poorly understood. Specifically, for skeletal muscle regeneration several models are reported in the literature, yet the relative impact on muscle physiology and the distinct cells types have not been extensively characterised.

METHODS

We have used transgenic Tg:Pax7nGFP and Flk1GFP/+ mouse models to respectively count the number of muscle stem (satellite) cells (SC) and number/shape of vessels by confocal microscopy. We performed histological and immunostainings to assess the differences in the key regeneration steps. Infiltration of immune cells, chemokines and cytokines production was assessed in vivo by Luminex®.

RESULTS

We compared the 4 most commonly used injury models i.e. freeze injury (FI), barium chloride (BaCl2), notexin (NTX) and cardiotoxin (CTX). The FI was the most damaging. In this model, up to 96% of the SCs are destroyed with their surrounding environment (basal lamina and vasculature) leaving a "dead zone" devoid of viable cells. The regeneration process itself is fulfilled in all 4 models with virtually no fibrosis 28 days post-injury, except in the FI model. Inflammatory cells return to basal levels in the CTX, BaCl2 but still significantly high 1-month post-injury in the FI and NTX models. Interestingly the number of SC returned to normal only in the FI, 1-month post-injury, with SCs that are still cycling up to 3-months after the induction of the injury in the other models.

CONCLUSIONS

Our studies show that the nature of the injury model should be chosen carefully depending on the experimental design and desired outcome. Although in all models the muscle regenerates completely, the trajectories of the regenerative process vary considerably. Furthermore, we show that histological parameters are not wholly sufficient to declare that regeneration is complete as molecular alterations (e.g. cycling SCs, cytokines) could have a major persistent impact.

Topics: Animals; Barium Compounds; Chlorides; Cobra Cardiotoxin Proteins; Cold Injury; Cytokines; Elapid Venoms; Fibrosis; Freezing; Green Fluorescent Proteins; Macrophages; Mice; Mice, Inbred C57BL; Mice, Transgenic; Models, Animal; Muscle Development; Muscle, Skeletal; Myoblasts; Necrosis; Neovascularization, Physiologic; Regeneration; Satellite Cells, Skeletal Muscle; Stem Cells; Vascular Endothelial Growth Factor Receptor-2

PubMed: 26807982
DOI: 10.1371/journal.pone.0147198

Authors: Gillian Rice, Teresa Patrick, Rekha Parmar...

Aicardi-Goutieres syndrome (AGS) is a genetic encephalopathy whose clinical features mimic those of acquired in utero viral infection. AGS exhibits locus heterogeneity, with mutations identified in genes encoding the 3'-->5' exonuclease TREX1 and the three subunits of the RNASEH2 endonuclease complex. To define the molecular spectrum of AGS, we performed mutation screening in patients, from 127 pedigrees, with a clinical diagnosis of the disease. Biallelic mutations in TREX1, RNASEH2A, RNASEH2B, and RNASEH2C were observed in 31, 3, 47, and 18 families, respectively. In five families, we identified an RNASEH2A or RNASEH2B mutation on one allele only. In one child, the disease occurred because of a de novo heterozygous TREX1 mutation. In 22 families, no mutations were found. Null mutations were common in TREX1, although a specific missense mutation was observed frequently in patients from northern Europe. Almost all mutations in RNASEH2A, RNASEH2B, and RNASEH2C were missense. We identified an RNASEH2C founder mutation in 13 Pakistani families. We also collected clinical data from 123 mutation-positive patients. Two clinical presentations could be delineated: an early-onset neonatal form, highly reminiscent of congenital infection seen particularly with TREX1 mutations, and a later-onset presentation, sometimes occurring after several months of normal development and occasionally associated with remarkably preserved neurological function, most frequently due to RNASEH2B mutations. Mortality was correlated with genotype; 34.3% of patients with TREX1, RNASEH2A, and RNASEH2C mutations versus 8.0% RNASEH2B mutation-positive patients were known to have died (P=.001). Our analysis defines the phenotypic spectrum of AGS and suggests a coherent mutation-screening strategy in this heterogeneous disorder. Additionally, our data indicate that at least one further AGS-causing gene remains to be identified.

Topics: Adolescent; Adult; Basal Ganglia Diseases; Brain; Calcinosis; Chilblains; Child; Child, Preschool; DNA Mutational Analysis; Exodeoxyribonucleases; Female; Humans; Infant; Infant, Newborn; Lymphocytosis; Male; Molecular Sequence Data; Mutation; Phenotype; Phosphoproteins; Ribonuclease H; Syndrome

PubMed: 17846997
DOI: 10.1086/521373

Review

Authors: Mia Demant, Elisabeth Lauritzen, Christian Lyngsaa Lang...

Thermal burns are by far the most frequent and account for approx. 90% of all burns, while frostbites, chemical and electrical burns (CB) cover the remaining approx. 10%. This review gives an overview of the treatment of corrosions and frostbites. CB and frostbites are relatively rare and prompt initiation of proper treatment is essential for both. CB should be diluted as soon as possible, preferably with a neutralizing solution. Treatment of systemic hypothermia comes before management of peripheral frostbite. Frostbites involve thawing in warm water, followed by vasodilation, thrombolysis and amputation if indicated.

Topics: Amputation, Surgical; Burns; Corrosion; Frostbite; Humans; Hypothermia

PubMed: 35060476
DOI: No ID Found

Authors: Clare M Eglin, Jennifer Wright, Matthew J Maley...

NEW FINDINGS

What is the central question of this study? Does non-freezing cold injury (NFCI) alter normal peripheral vascular function? What is the main finding and its importance? Individuals with NFCI were more cold sensitive (rewarmed more slowly and felt more discomfort) than controls. Vascular tests indicated that extremity endothelial function was preserved with NFCI and that sympathetic vasoconstrictor response might be reduced. The pathophysiology underpinning the cold sensitivity associated with NFCI thus remains to be identified.

ABSTRACT

The impact of non-freezing cold injury (NFCI) on peripheral vascular function was investigated. Individuals with NFCI (NFCI group) and closely matched controls with either similar (COLD group) or limited (CON group) previous cold exposure were compared (n = 16). Peripheral cutaneous vascular responses to deep inspiration (DI), occlusion (PORH), local cutaneous heating (LH) and iontophoresis of acetylcholine and sodium nitroprusside were investigated. The responses to a cold sensitivity test (CST) involving immersion of a foot in 15°C water for 2 min followed by spontaneous rewarming, and a foot cooling protocol (footplate cooled from 34°C to 15°C), were also examined. The vasoconstrictor response to DI was lower in NFCI compared to CON (toe: 73 (28)% vs. 91 (17)%; P = 0.003). The responses to PORH, LH and iontophoresis were not reduced compared to either COLD or CON. During the CST, toe skin temperature rewarmed more slowly in NFCI than COLD or CON (10 min: 27.4 (2.3)°C vs. 30.7 (3.7)°C and 31.7 (3.9)°C, P < 0.05, respectively); however, no differences were observed during the footplate cooling. NFCI were more cold-intolerant (P < 0.0001) and reported colder and more uncomfortable feet during the CST and footplate cooling than COLD and CON (P < 0.05). NFCI showed a decreased sensitivity to sympathetic vasoconstrictor activation than CON and greater cold sensitivity (CST) compared to COLD and CON. None of the other vascular function tests indicated endothelial dysfunction. However, NFCI perceived their extremities to be colder and more uncomfortable/painful than the controls.

Topics: Humans; Cold Injury; Cold Temperature; Skin Temperature; Temperature; Vasoconstrictor Agents

PubMed: 36807667
DOI: 10.1113/EP090721

Authors: Jennifer Wright, Heather Massey, Sarah Hollis...

What is the central question of this study? Is peripheral sensory function impaired in the chronic phase of non-freezing cold injury (NFCI)? What is the main finding and its importance? Warm and mechanical detection thresholds are elevated and intraepidermal nerve fibre density is reduced in individuals with NFCI in their feet when compared to matched controls. This indicates impaired sensory function in individuals with NFCI. Interindividual variation was observed in all groups, and therefore a diagnostic cut-off for NFCI has yet to be established. Longitudinal studies are required to follow NFCI progression from formation to resolution ABSTRACT: The aim of this study was to compare peripheral sensory neural function of individuals with non-freezing cold injury (NFCI) with matched controls (without NFCI) with either similar (COLD) or minimal previous cold exposure (CON). Thirteen individuals with chronic NFCI in their feet were matched with the control groups for sex, age, race, fitness, body mass index and foot volume. All undertook quantitative sensory testing (QST) on the foot. Intraepidermal nerve fibre density (IENFD) was assessed 10 cm above the lateral malleolus in nine NFCI and 12 COLD participants. Warm detection threshold was higher at the great toe in NFCI than COLD (NFCI 45.93 (4.71)°C vs. COLD 43.44 (2.72)°C, P = 0.046), but was non-significantly different from CON (CON 43.92 (5.01)°C, P = 0.295). Mechanical detection threshold on the dorsum of the foot was higher in NFCI (23.61 (33.59) mN) than in CON (3.83 (3.69) mN, P = 0.003), but was non-significantly different from COLD (10.49 (5.76) mN, P > 0.999). Remaining QST measures did not differ significantly between groups. IENFD was lower in NFCI than COLD (NFCI 8.47 (2.36) fibre/mm vs. COLD 11.93 (4.04) fibre/mm , P = 0.020). Elevated warm and mechanical detection thresholds may indicate hyposensitivity to sensory stimuli in the injured foot for individuals with NFCI and may be due to reduced innervation given the reduction in IENFD. Longitudinal studies are required to identify the progression of sensory neuropathy from the formation of injury to its resolution, with appropriate control groups employed.

Topics: Humans; Cold Injury; Sensation; Foot; Cold Temperature

PubMed: 36807948
DOI: 10.1113/EP090720

Review

Authors: Nicholas M Teets, Katie E Marshall, Julie A Reynolds...

Winter provides many challenges for insects, including direct injury to tissues and energy drain due to low food availability. As a result, the geographic distribution of many species is tightly coupled to their ability to survive winter. In this review, we summarize molecular processes associated with winter survival, with a particular focus on coping with cold injury and energetic challenges. Anticipatory processes such as cold acclimation and diapause cause wholesale transcriptional reorganization that increases cold resistance and promotes cryoprotectant production and energy storage. Molecular responses to low temperature are also dynamic and include signaling events during and after a cold stressor to prevent and repair cold injury. In addition, we highlight mechanisms that are subject to selection as insects evolve to variable winter conditions. Based on current knowledge, despite common threads, molecular mechanisms of winter survival vary considerably across species, and taxonomic biases must be addressed to fully appreciate the mechanistic basis of winter survival across the insect phylogeny.

Topics: Animals; Seasons; Insecta; Cold Temperature; Cold Injury

PubMed: 36206770
DOI: 10.1146/annurev-ento-120120-095233

Authors: Pernille Linde Jellestad, Morten Olskjær Holm

This is a case report of a 39-year-old man who participated in a cross-country skiing race in Alaska. A few minutes with a glove-free hand resulted in frostbites. Medical assistance arrived 24 hours later and enoxaparine was administered. After seven days, hyperbaric oxygen therapy (HBOT) was initiated in Denmark. After 90 days the distal part of the second finger was removed due to mummification. Compared with the original extent of the injury the amputated part was significantly smaller. HBOT as treatment has not yet been described in Danish patients and is only used on an experimental basis worldwide.

Topics: Male; Humans; Adult; Hyperbaric Oxygenation; Oxygen; Frostbite

PubMed: 37114592
DOI: No ID Found

Review

Authors: Samantha Schneider, Cecilia Blair Levandowski, Cory Manly...

Exploring the mountains is a highly rewarding past time; however, certain high-altitude exposures can lead to dermatologic manifestations. In this review article, the authors will describe cold, solar, and severe weather that one may experience when spending time outdoors. Factors such as increased ultraviolet radiation, temperature extremes, and low partial pressure of oxygen, along with human physiologic parameters also contribute to disease severity and presentation. This review article will address the diagnosis, treatment, and prevention of high-altitude dermatology exposures.

Topics: Altitude; Cold Injury; Dermatology; Humans; Mountaineering; Skin Diseases; Ultraviolet Rays; Weather

PubMed: 29447629
DOI: No ID Found

Authors: Huyun Chen, Bradley W Ellis, Antonia T Dinicu...

Current methods of storing explanted donor livers at 4°C in University of Wisconsin (UW) solution result in loss of graft function and ultimately leads to less-than-ideal outcomes post transplantation. Our lab has previously shown that supplementing UW solution with 35-kilodalton polyethylene glycol (PEG) has membrane stabilizing effects for cold stored primary rat hepatocytes in suspension. Expanding on past studies, we here investigate if PEG has the same beneficial effects in an adherent primary rat hepatocyte cold storage model. In addition, we investigated the extent of cold-induced apoptosis through treating cold-stored hepatocytes with pan caspase inhibitor emricasan. In parallel to storage at the current cold storage standard of 4°C, we investigated the effects of lowering the storage temperature to -4°C, at which the storage solution remains ice-free due to the supercooling phenomenon. We show the addition of 5% PEG to the storage medium significantly reduced the release of lactate dehydrogenase (LDH) in plated rat hepatocytes and a combinatorial treatment with emricasan maintains hepatocyte viability and morphology following recovery from cold storage. These results show that cold-stored hepatocytes undergo multiple mechanisms of cold-induced injury and that PEG and emricasan treatment in combination with supercooling may improve cell and organ preservation.

PubMed: 38076969
DOI: 10.21203/rs.3.rs-3669876/v1