Manifestations of cutaneous diabetic microangiopathy

Cutaneous manifestations of diabetes mellitus: a narrative review

Diabetes mellitus is a highly prevalent human endocrine disorder. Skin lesions are reported in approximately one-third of all diabetes mellitus patients. The clinical presentation and frequency vary according to the subtype of diabetes mellitus, metabolic control, and clinical course, with certain skin diseases occurring before diagnosing hyperglycemia. In this regard, the correct definition of cutaneous manifestations associated with diabetes mellitus can help define the etiology of hyperglycemia as well as the need to optimize glycemic control. In this narrative review, the most common cutaneous diseases observed in diabetes mellitus are discussed, including pruritus, acanthosis nigricans, necrobiosis lipoidica, bullosis diabeticorum, scleroderma diabeticorum, granuloma annulare, diabetic dermopathy, skin reactions due to device use, diabetic foot ulcers, recurrent cutaneous infections in diabetes mellitus and other dermatoses associated with hyperglycemia. The epidemiology, pathophysiology, differential diagnosis, and treatment of this disease are discussed. Therefore, knowledge and recognition of the most common dermatological lesions in patients with diabetes mellitus are essential for both endocrinologists and primary care physicians.

The role of SLC7A11 in diabetic wound healing: novel insights and new therapeutic strategies

Diabetic wounds are a severe complication of diabetes, characterized by persistent, non-healing ulcers due to disrupted wound-healing mechanisms in a hyperglycemic environment. Key factors in the pathogenesis of these chronic wounds include unresolved inflammation and antioxidant defense imbalances. The cystine/glutamate antiporter SLC7A11 (xCT) is crucial for cystine import, glutathione production, and antioxidant protection, positioning it as a vital regulator of diabetic wound healing. Recent studies underscore the role of SLC7A11 in modulating immune responses and oxidative stress in diabetic wounds. Moreover, SLC7A11 influences critical processes such as insulin secretion and the mTOR signaling pathway, both of which are implicated in delayed wound healing. This review explores the mechanisms regulating SLC7A11 and its impact on immune response, antioxidant defenses, insulin secretion, and mTOR pathways in diabetic wounds. Additionally, we highlight the current advancements in targeting SLC7A11 for treating related diseases and conceptualize its potential applications and value in diabetic wound treatment strategies, along with the challenges encountered in this context.

Phytoconstituents as modulators of NF-κB signalling: Investigating therapeutic potential for diabetic wound healing

The NF-κB pathway plays a pivotal role in impeding the diabetic wound healing process, contributing to prolonged inflammation, diminished angiogenesis, and reduced proliferation. In contrast to modern synthetic therapies, naturally occurring phytoconstituents are well-studied inhibitors of the NF-κB pathway that are now attracting increased attention in the context of diabetic wound healing because of lower toxicity, better safety and efficacy, and cost-effectiveness. This study explores recent research on phytoconstituent-based therapies and delve into their action mechanisms targeting the NF-κB pathway and potential for assisting effective healing of diabetic wounds. For this purpose, we have carried out surveys of recent literature and analyzed studies from prominent databases such as Science Direct, Scopus, PubMed, Google Scholar, EMBASE, and Web of Science. The classification of phytoconstituents into various categorie such as: alkaloids, triterpenoids, phenolics, polyphenols, flavonoids, monoterpene glycosides, naphthoquinones and tocopherols. Noteworthy phytoconstituents, including Neferine, Plumbagin, Boswellic acid, Genistein, Luteolin, Kirenol, Rutin, Vicenin-2, Gamma-tocopherol, Icariin, Resveratrol, Mangiferin, Betulinic acid, Berberine, Syringic acid, Gallocatechin, Curcumin, Loureirin-A, Loureirin-B, Lupeol, Paeoniflorin, and Puerarin emerge from these studies as promising agents for diabetic wound healing through the inhibition of the NF-κB pathway. Extensive research on various phytoconstituents has revealed how they modulate signalling pathways, including NF-κB, studies that demonstrate the potential for development of therapeutic phytoconstituents to assist healing of chronic diabetic wounds.

Type I Diabetes Mellitus Suppresses Experimental Skin Carcinogenesis

This study explores the previously uncharted territory of the effects of ultraviolet (UV) radiation on diabetic skin, compared to its well-documented impact on normal skin, particularly focusing on carcinogenesis and aging. Employing hairless SKH-hr2, Type 1 and 2 diabetic, and nondiabetic male mice, the research subjected these to UV radiation thrice weekly for eight months. The investigation included comprehensive assessments of photoaging and photocarcinogenesis in diabetic versus normal skin, measuring factors such as hydration, trans-epidermal water loss, elasticity, skin thickness, melanin, sebum content, stratum corneum exfoliation and body weight, alongside photo documentation. Additionally, oxidative stress and the presence of hydrophilic antioxidants (uric acid and glutathione) in the stratum corneum were evaluated. Histopathological examination post-sacrifice provided insights into the morphological changes. Findings reveal that under UV exposure, Type 1 diabetic skin showed heightened dehydration, thinning, and signs of accelerated aging. Remarkably, Type 1 diabetic mice did not develop squamous cell carcinoma or pigmented nevi, contrary to normal and Type 2 diabetic skin. This unexpected resistance to UV-induced skin cancers in Type 1 diabetic skin prompts a crucial need for further research to uncover the underlying mechanisms providing this resistance.

A novel multi-feature learning model for disease diagnosis using face skin images

BACKGROUND

Facial skin characteristics can provide valuable information about a patient's underlying health conditions.

OBJECTIVE

In practice, there are often samples with divergent characteristics (commonly known as divergent samples) that can be attributed to environmental factors, living conditions, or genetic elements. These divergent samples significantly degrade the accuracy of diagnoses.

METHODOLOGY

To tackle this problem, we propose a novel multi-feature learning method called Multi-Feature Learning with Centroid Matrix (MFLCM), which aims to mitigate the influence of divergent samples on the accurate classification of samples located on the boundary. In this approach, we introduce a novel discriminator that incorporates a centroid matrix strategy and simultaneously adapt it to a classifier in a unified model. We effectively apply the centroid matrix to the embedding feature spaces, which are transformed from the multi-feature observation space, by calculating a relaxed Hamming distance. The purpose of the centroid vectors for each category is to act as anchors, ensuring that samples from the same class are positioned close to their corresponding centroid vector while being pushed further away from the remaining centroids.

RESULTS

Validation of the proposed method with clinical facial skin dataset showed that the proposed method achieved F1 scores of 92.59%, 83.35%, 82.84% and 85.46%, respectively for the detection the Healthy, Diabetes Mellitus (DM), Fatty Liver (FL) and Chronic Renal Failure (CRF).

CONCLUSION

Experimental results demonstrate the superiority of the proposed method compared with typical classifiers single-view-based and state-of-the-art multi-feature approaches. To the best of our knowledge, this study represents the first to demonstrate concept of multi-feature learning using only facial skin images as an effective non-invasive approach for simultaneously identifying DM, FL and CRF in Han Chinese, the largest ethnic group in the world.

Dermal features derived from optoacoustic tomograms via machine learning correlate microangiopathy phenotypes with diabetes stage

Skin microangiopathy has been associated with diabetes. Here we show that skin-microangiopathy phenotypes in humans can be correlated with diabetes stage via morphophysiological cutaneous features extracted from raster-scan optoacoustic mesoscopy (RSOM) images of skin on the leg. We obtained 199 RSOM images from 115 participants (40 healthy and 75 with diabetes), and used machine learning to segment skin layers and microvasculature to identify clinically explainable features pertaining to different depths and scales of detail that provided the highest predictive power. Features in the dermal layer at the scale of detail of 0.1-1 mm (such as the number of junction-to-junction branches) were highly sensitive to diabetes stage. A 'microangiopathy score' compiling the 32 most-relevant features predicted the presence of diabetes with an area under the receiver operating characteristic curve of 0.84. The analysis of morphophysiological cutaneous features via RSOM may allow for the discovery of diabetes biomarkers in the skin and for the monitoring of diabetes status.

Diabetic microvascular disease in non-classical beds: the hidden impact beyond the retina, the kidney, and the peripheral nerves

Diabetes microangiopathy, a hallmark complication of diabetes, is characterised by structural and functional abnormalities within the intricate network of microvessels beyond well-known and documented target organs, i.e., the retina, kidney, and peripheral nerves. Indeed, an intact microvascular bed is crucial for preserving each organ's specific functions and achieving physiological balance to meet their respective metabolic demands. Therefore, diabetes-related microvascular dysfunction leads to widespread multiorgan consequences in still-overlooked non-traditional target organs such as the brain, the lung, the bone tissue, the skin, the arterial wall, the heart, or the musculoskeletal system. All these organs are vulnerable to the physiopathological mechanisms that cause microvascular damage in diabetes (i.e., hyperglycaemia-induced oxidative stress, inflammation, and endothelial dysfunction) and collectively contribute to abnormalities in the microvessels' structure and function, compromising blood flow and tissue perfusion. However, the microcirculatory networks differ between organs due to variations in haemodynamic, vascular architecture, and affected cells, resulting in a spectrum of clinical presentations. The aim of this review is to focus on the multifaceted nature of microvascular impairment in diabetes through available evidence of specific consequences in often overlooked organs. A better understanding of diabetes microangiopathy in non-target organs provides a broader perspective on the systemic nature of the disease, underscoring the importance of recognising the comprehensive range of complications beyond the classic target sites.

Immune Fitness, Migraine, and Headache Complaints in Individuals with Self-Reported Impaired Wound Healing

Background

Having chronic wounds and impaired wound healing are associated with psychological distress. The current study aims to evaluate migraine and headache complaints in young adults with self-reported impaired wound healing.

Methods

A survey was conducted among N=1935 young adults (83.6% women), 18-30 years old, living in the Netherlands. Wound healing status was verified, immune fitness was assessed using a single-item rating scale, and ID Migraine was completed. In addition, several questions were answered on past year's headache experiences (including frequency, quantity, type, location, and severity).

Results

In both the control group (p < 0.001) and the IWH group (p = 0.002) immune fitness was significantly lower among those that reported headaches compared to those that reported no headaches. Individuals with self-reported impaired wound healing (IWH) scored significantly higher on the ID Migraine scale, and individuals of the IWH group scored significantly more often positive for migraine (ie, an ID Migraine score ≥2). They reported a younger age of onset of experiencing headaches, and significantly more often reported having a beating or pounding headache than the control group. Compared to the control group, the IWH group reported being significantly more limited in their daily activities compared to the control group.

Conclusion

Headaches and migraines are more frequently reported by individuals with self-reported impaired wound healing, and their reported immune fitness is significantly poorer compared to healthy controls. These headache and migraine complaints significantly limit them in their daily activities.

Multiple color representation and fusion for diabetes mellitus diagnosis based on back tongue images

Tongue images have been proved to be effective in diabetes mellitus (DM) diagnosis. Without requirement of collecting blood sample, tongue image based diagnosis approach is non-invasive and convenient for the patients. Meanwhile, the colors of tongues play an important in aiding accurate diagnosis. However, the tongues' colors fall on a small color gamut that makes it difficult for the existing color descripts to identify and distinguish the tiny difference of the tongues. To tackle this problem, we introduce a novel color descriptor by representing the colors with the clustering centers, namely color centroid points, of the color points sampled from tongue images. In order to boost the capacity of the descriptor, we extend it into three color spaces, i.e., RGB, HSV and LAB to mine a rich set of color information and exploit the complementary information among the three spaces. Since there exist correlation and complementarity among the features extracted from the three color spaces, we propose a novel multiple color features fusion method for DM diagnosis. Particularly, two projections are learned to project the multiple features to their corresponding shared and specific subspaces, in which their similarity and diversity are firstly measured by the Euclidean Distance and Hilbert Schmidt Independence Criterion (HSIC), respectively. To fully exploit the similar and complementary information, the two components are jointly transformed to their label vector, efficiently embedding the discriminant prior into the model, leading to significant improvement in the diagnosis outcomes. Experimental results on clinical tongue dataset substantiated the effectiveness of our proposed clustering-based color descriptor and the proposed multiple colors fusion approach. Overall, the proposed pipeline for the diagnosis of DM using back tongue images, achieved an average accuracy of up to 93.38%, indicating its potential toward realization of a clinical diagnostic tool for DM. Without loss generality, we also assessed the performance of the novel multiple features fusion method on two public datasets. The experiments prove the superiority of our multiple features learning model on general real-life application.

Diabetic Peripheral Neuropathy Associated with Foot Ulcer: One of a Kind

Significance: Diabetic peripheral neuropathy (DPN) associated with a diabetic foot ulcer (DFU) is likely to be complicated with critical factors such as biofilm infection and compromised skin barrier function of the diabetic skin. Repaired skin with a history of biofilm infection is known to be compromised in barrier function. Loss of barrier function is also observed in the oxidative stress affected diabetic and aged skin. Recent Advances: Loss of barrier function makes the skin prone to biofilm infection and cellulitis, which contributes to chronic inflammation and vasculopathy. Hyperglycemia favors biofilm formation as glucose lowering led to reduction in biofilm development. While vasculopathy limits oxygen supply, the O2 cost of inflammation is high increasing hypoxia severity. Critical Issues: The host nervous system can be inhabited by bacteria. Because electrical impulses are a part of microbial physiology, polymicrobial colonization of the host's neural circuit is likely to influence transmission of action potential. The identification of perineural apatite in diabetic patients with peripheral neuropathy suggests bacterial involvement. DPN starts in both feet at the same time. Future Directions: Pair-matched studies of DPN in the foot affected with DFU (i.e., DFU-DPN) compared with DPN in the without ulcer, and intact skin barrier function, are likely to provide critical insight that would help inform effective care strategies. This review characterizes DFU-DPN from a translational science point of view presenting a new paradigm that recognizes the current literature in the context of factors that are unique to DFU-DPN.

Juvenile diabetes and systemic sclerosis: just a coincidence?

BACKGROUND

Limited joint mobility (LJM), previously known as cheiroarthropathy, refers to the presence of reduced extension at the finger joints in people with diabetes and may be associated with scleroderma-like syndromes such as diabetic sclerodactyly. While scleroderma-like syndromes and LJM have been observed in patients with long-term diabetes and associated complications, the coexistence of diabetes with Juvenile systemic sclerosis (jSSc) is rarely described.

CASE PRESENTATION

We describe the case of a 14-year-old boy with long-lasting type 1 diabetes (T1D) and suspected LJM associated with Raynaud phenomenon, sclerodactyly and tapering of the fingertips. A comprehensive work-up showed positive autoantibodies (ANA, anti-Ro-52, anti-Mi-2b), abnormal nailfold capillaroscopy with a scleroderma pattern, interstitial lung disease and cardiac involvement. The overall clinical picture was consistent with the diagnosis of jSSc.

CONCLUSIONS

LJM can be the initial sign of underlying systemic sclerosis. Nailfold capillaroscopy may help differentiate jSSc from classical LJM in pediatric patients with T1D and finger contractures or skin induration of no clear origin. This case report provides a starting point for a novel hypothesis regarding the pathogenesis of jSSc. The association between T1D and jSSc may be more than a coincidence and could suggest a relationship between glucose metabolism, fibrosis and microangiopathy.

Histopathology of autoimmune bullous dermatoses: What's new?

Autoimmune bullous dermatoses are characterized by the presence of tissue-bound and often circulating pathogenic autoantibodies targeting structural components of the skin and/or mucous membranes. The diagnostic workup for this heterogeneous group of disorders consists of a multi-step process, of which the light microscopic examination is a crucial component. This review is organized following a classification scheme that is based on two main histopathologic features, namely level of intraepithelial split and composition of the inflammatory infiltrate. Overall, we aim to place emphasis on the histopathologic clues that can assist pathologists in differential diagnosis and review the updates in the literature.

The Role of Oxidative Stress and Antioxidants in Diabetic Wound Healing

Foot ulcers are one of the most common and severe complication of diabetes mellitus with significant resultant morbidity and mortality. Multiple factors impair wound healing include skin injury, diabetic neuropathy, ischemia, infection, inadequate glycemic control, poor nutritional status, and severe morbidity. It is currently believed that oxidative stress plays a vital role in diabetic wound healing. An imbalance of free radicals and antioxidants in the body results in overproduction of reactive oxygen species which lead to cell, tissue damage, and delayed wound healing. Therefore, decreasing ROS levels through antioxidative systems may reduce oxidative stress-induced damage to improve healing. In this context, we provide an update on the role of oxidative stress and antioxidants in diabetic wound healing through following four perspectives. We then discuss several therapeutic strategies especially dietary bioactive compounds by targeting oxidative stress to improve wounds healing.

Necrobiosis lipoidica-like lesions in a nondiabetic patient with systemic sarcoidosis: A case report and review of the literature

Necrobiosis lipoidica-like lesions, in known cases of sarcoidosis, can be considered as a member of the broad spectrum of histologic changes in sarcoidosis.

Non-invasive detection of diabetic complications via pattern analysis of temporal facial colour variations

BACKGROUND AND OBJECTIVE

Diabetes mellitus is a common disorder amounting to 400 million patients worldwide. It is often accompanied by a number of complications, including neuropathy, nephropathy, and cardiovascular diseases. For example, peripheral neuropathy is present among 20-30% of diabetics before the diagnosis is substantiated. For this reason, a reliable detection method for diabetic complications is crucial and attracts a lot of research attention.

METHODS

In this paper, we introduce a non-invasive detection framework for patients with diabetic complications that only requires short video recordings of faces from a standard commercial camera. We employed multiple image processing and pattern recognition techniques to process video frames, extract relevant information, and predict the health status. To evaluate our framework, we collected a dataset of 114 video files from diabetic patients, who were diagnosed with diabetes for years and 60 video files from the control group. Extracted features from videos were tested using two conceptually different classifiers.

RESULTS

We found that our proposed framework correctly identifies patients with diabetic complications with 92.86% accuracy, 100% sensitivity, and 80% specificity.

CONCLUSIONS

Our study brings a novel perspective on diagnosis procedures in this field. We used multiple techniques from image processing, pattern recognition, and machine learning to robustly process video frames and predict the health status of our subjects with high efficiency.

Quantifying dermal microcirculatory changes of neuropathic and neuroischemic diabetic foot ulcers using spatial frequency domain imaging: a shade of things to come?

INTRODUCTION

The use of non-invasive vascular and perfusion diagnostics are an important part of assessing lower extremity ulceration and amputation risk in patients with diabetes mellitus. Methods for detecting impaired microvascular vasodilatory function in patients with diabetes may have the potential to identify sites at risk of ulceration prior to clinically identifiable signs. Spatial frequency domain imaging (SFDI) uses patterned near-infrared and visible light spectroscopy to determine tissue oxygen saturation and hemoglobin distribution within the superficial and deep dermis, showing distinct microcirculatory and oxygenation changes that occur prior to neuropathic and neuroischemic ulceration.

RESEARCH DESIGNS AND METHODS

35 patients with diabetes mellitus and a history of diabetic foot ulceration were recruited for monthly imaging with SFDI. Two patients who ulcerated during the year-long longitudinal study were selected for presentation of their clinical course alongside the dermal microcirculation biomarkers from SFDI.

RESULTS

Patient 1 developed a neuropathic ulcer portended by a focal increase in tissue oxygen saturation and decrease in superficial papillary hemoglobin concentration 3 months prior. Patient 2 developed bilateral neuroischemic ulcers showing decreased tissue oxygen saturation and increased superficial papillary and deep dermal reticular hemoglobin concentrations.

CONCLUSIONS

Wounds of different etiology show unique dermal microcirculatory changes prior to gross ulceration. Before predictive models can be developed from SFDI, biomarker data must be correlated with the clinical course of patients who ulcerate while being followed longitudinally.

TRIAL REGISTRATION NUMBER

NCT03341559.

Individual Responses to Heat Stress: Implications for Hyperthermia and Physical Work Capacity

Background

Extreme heat events are increasing in frequency, severity, and duration. It is well known that heat stress can have a negative impact on occupational health and productivity, particularly during physical work. However, there are no up-to-date reviews on how vulnerability to heat changes as a function of individual characteristics in relation to the risk of hyperthermia and work capacity loss. The objective of this narrative review is to examine the role of individual characteristics on the human heat stress response, specifically in relation to hyperthermia risk and productivity loss in hot workplaces. Finally, we aim to generate practical guidance for industrial hygienists considering our findings. Factors included in the analysis were body mass, body surface area to mass ratio, body fat, aerobic fitness and training, heat adaptation, aging, sex, and chronic health conditions.

Findings

We found the relevance of any factor to be dynamic, based on the work-type (fixed pace or relative to fitness level), work intensity (low, moderate, or heavy work), climate type (humidity, clothing vapor resistance), and variable of interest (risk of hyperthermia or likelihood of productivity loss). Heat adaptation, high aerobic fitness, and having a large body mass are the most protective factors during heat exposure. Primary detrimental factors include low fitness, low body mass, and lack of heat adaptation. Aging beyond 50 years, being female, and diabetes are less impactful negative factors, since their independent effect is quite small in well matched participants. Skin surface area to mass ratio, body composition, hypertension, and cardiovascular disease are not strong independent predictors of the heat stress response.

Conclusion

Understanding how individual factors impact responses to heat stress is necessary for the prediction of heat wave impacts on occupational health and work capacity. The recommendations provided in this report could be utilized to help curtail hyperthermia risk and productivity losses induced by heat.

Clinical Significance of Diabetic Dermatopathy

Diabetic dermopathy is a cutaneous manifestation commonly seen in diabetes patients and was initially described by Melin in 1964. These lesions are well-demarcated, hyperpigmented macules or papules with atrophic depression and were commonly sighted on shins of the tibia with bilateral asymmetrical distribution and rarely seen on arms, thighs and abdomen. The incidence of DD ranges from 0.2 to 55%. It has been frequently associated with microangiopathic complications of diabetes such as nephropathy, retinopathy and polyneuropathy. Although the exact mechanism of occurrence is unknown, it may be related to impaired wound healing due to decreased blood flow, local thermal trauma or local subcutaneous nerve degeneration. Diagnosis is made by clinical examination and the differential diagnosis includes stasis dermatitis, early lesion of necrobiosis lipoidica and purpuric dermatitis. Prevention of dermopathy lesions includes optimized glucose control. No active treatment is recommended or proven effective and DD is known to resolve on its own as time passes. Modified collagen and high glycerine-based lotion have shown marked improvement in skin color changes due to diabetic dermopathy. Diabetic dermopathy is known to have a strong association with microangiopathic complications; the presence of such lesions must raise strong suspicion and prompt investigation for severe underlying pathology. Enhanced scrutinized glycemic control in diabetic dermatopathy patients can even lead to abatement in further progression to microvascular complications and improved long-term patient outcomes.

Cutaneous microangiopathy in patients with type 2 diabetes: Impaired vascular endothelial growth factor expression and its correlation with neuropathy, retinopathy and nephropathy

AIMS/INTRODUCTION

To examine the three-dimensional morphology and vascular endothelial growth factor (VEGF) expression of skin microvasculature in patients with type 2 diabetes in relation to neuropathy, retinopathy and nephropathy.

MATERIALS AND METHODS

The present study enrolled 17 individuals with type 2 diabetes and 16 without. Skin sections were double-immunostained for type IV collagen and VEGF-A or protein gene product 9.5. Projected images from confocal microscopy served to quantify the occupancy rate of subepidermal type IV collagen-immunoreactive microvascular basement membrane area (OR-T4MBM), subepidermal VEGF-A-immunoreactive area and the VEGF/T4MBM ratio, as well as the protein gene product 9.5-immunoreactive intraepidermal nerve fiber density. Reduced intraepidermal nerve fiber density was applied for the diagnosis of neuropathy, fundic ophthalmoscopy and fluorescein angiography for retinopathy, and microalbuminuria or persistent proteinuria for nephropathy.

RESULTS

A total of 12 patients with diabetes had neuropathy, 10 had retinopathy and eight had nephropathy. Regardless of the presence or absence of neuropathy, retinopathy or nephropathy, OR-T4MBM was significantly increased in patients with diabetes compared with individuals without diabetes. In contrast, VEGF/T4MBM ratio was significantly decreased in those with neuropathy and retinopathy, as well as in those with and without nephropathy, whereas a trend toward a decreased VEGF/T4MBM ratio was seen in patients without retinopathy, as compared with individuals without diabetes.

CONCLUSIONS

The present study is the first report to show that cutaneous microangiopathy, as indicated by subepidermal microvascular proliferation and impaired VEGF expression, appears to occur before the development of overt clinical neuropathy, retinopathy or nephropathy in patients with type 2 diabetes.

Invisible Color Variations of Facial Erythema: A Novel Early Marker for Diabetic Complications?

AIM

(1) To quantify the invisible variations of facial erythema that occur as the blood flows in and out of the face of diabetic patients, during the blood pulse wave using an innovative image processing method, on videos recorded with a conventional digital camera and (2) to determine whether this "unveiled" facial red coloration and its periodic variations present specific characteristics in diabetic patients different from those in control subjects.

METHODS

We video recorded the faces of 20 diabetic patients with peripheral neuropathy, retinopathy, and/or nephropathy and 10 nondiabetic control subjects, using a Canon EOS camera, for 240 s. Only one participant presented visible facial erythema. We applied novel image processing methods to make the facial redness and its variations visible and automatically detected and extracted the redness intensity of eight facial patches, from each frame. We compared average and standard deviations of redness in the two groups using t-tests.

RESULTS

Facial redness varies, imperceptibly and periodically, between redder and paler, following the heart pulsation. This variation is consistently and significantly larger in diabetic patients compared to controls (p value < 0.001).

CONCLUSIONS

Our study and its results (i.e., larger variations of facial redness with the heartbeats in diabetic patients) are unprecedented. One limitation is the sample size. Confirmation in a larger study would ground the development of a noninvasive cost-effective automatic tool for early detection of diabetic complications, based on measuring invisible redness variations, by image processing of facial videos captured at home with the patient's smartphone.

Relation between cutaneous and extracutaneous complications in pediatric patients with type 1 diabetes

Background: The relationship between cutaneous and extracutaneous complications in pediatric patients with type 1 diabetes is unclear. Objective: The objective of the current study is to investigate the relationship between skin disorders and diabetic microangiopathic changes in pediatric and adolescent patients with type 1 diabetes. Patients and methods: Eighty patients with type 1 diabetes and 50 healthy controls were enrolled in the study. All recruited patients were followed up monthly for a total period of 12 month. Monthly visit included thorough clinical examination with system review, as well as whole-body cutaneous examination. HbA1c was assessed every 3 month. Twenty-four hours urine was collected for measurement of urinary albumin. Results: Fifty percent of the screened diabetic cohort had diabetic nephropathy (DN). The overall prevalence of cutaneous lesion among the studied diabetic cohort was high (72.5%), with cutaneous infections (40%) and xerosis (30%) being the most prevalent. The frequency of cutaneous infections, xerosis and rubeosis faciei was higher in patients with nephropathy than in those without nephropathy. Conclusion: cutaneous affection in patients with diabetes may be a clue to the presence of associated microangioapthic complications. The significant association between diabetic nephropathy and cutaneous lesions support the concept that cutaneous lesion in diabetes is a reflection of diabetic angiopathy, highlighting the importance of identifying patients at risk of other microvascular complications.

Vascular diseases in the mature patient

Aging results in both anatomic and physiologic changes in the skin's structure and vascular system. These vascular changes result in a wide array of dermatologic findings, ranging from the benign to the highly morbid. Herein, we review the impact of both intrinsic and common extrinsic factors of aging on cutaneous vasculature and highlight the manifestations of microvascular, venous, arterial, lymphatic, and neuropathic alterations in the geriatric population.

Association of Diabetes and Insulin Therapy With Risk of Hospitalization for Infection and 28-Day Mortality Risk

Background

Epidemiologic and experimental evidence suggests that individuals with diabetes are at increased risk of infection. We sought to examine the association of diabetes and insulin therapy with hospitalization for infection and 28-day mortality.

Methods

We performed a prospective cohort study using data from 30 239 community-dwelling participants aged ≥45 years enrolled in the REasons for Geographic and Racial Differences in Stroke (REGARDS) study. We defined diabetes as a fasting glucose level ≥126 mg/L (or ≥200 mg/L for those not fasting), the use of insulin or oral hypoglycemic agents, or self-reported history. We identified infection-related hospitalizations over the years 2003–2012. We fit Cox proportional hazards models to assess the association of diabetes with hazard rates of infection and logistic regression models for 28-day mortality.

Results

Among 29 683 patients from the REGARDS study with complete follow-up, 7375 had diabetes. Over a median follow-up period of 6.5 years, we identified 2593 first and 3411 total infection hospitalizations. In adjusted analyses, participants with diabetes had an increased hazard of infection (hazard ratio, 1.50; 95% confidence interval [CI], 1.37–1.64) compared with those without diabetes. Participants with diabetes hospitalized for infection did not have an increased odds of death within 28 days (odds ratio, 0.94; 95% CI, .67–1.32). Participants receiving insulin therapy had greater hazard of infection (hazard ratio, 2.18; 95% CI, 1.90–2.51) but no increased odds of mortality (odd ratio, 1.07; 95% CI, .67–1.71).

Conclusions

Diabetes is associated with increased risk of hospitalization for infection. However, we did not find an association with 28-day mortality. Insulin therapy conferred an even greater risk of hospitalization, without increased mortality.

The association between Solar Lentigines and Type-2 Diabetes

Background

Limited information exists between the associations of diabetes mellitus (DM) and solar lentigo (SL); a benign, common skin lesion characterized by hyperpigmented macules.

Methods

This study was conducted on 90 patients diagnosed with DM and their age and sex matched controls who were referred to the Departments of Endocrinology at Babol University of Medical Science in Northern of Iran from January 2013 to December 2015. All demographic data including age, gender, occupation, family history of DM, estimated average sun exposure and presence of skin lesions were collected and analyzed.

Results

Presence of SL was significantly higher among patients with DM compared to controls (61.9% vs 33.6%, P<0.001). After adjusting for age, sex and sun exposure rate, results indicated that DM was independently associated with the presence of SL (p=0.002). Stratifying patients based on gender, indicated that DM was significantly associated with SL in females (p=0.03), but not in male patients (p=0.06).

Conclusion

The findings of the present study indicate that DM is an independent risk factor for the occurrence of SL lesions. These findings could represent a novel association between DM as a chronic oxidation state and SL as an early sign of aging.

Diabetes mellitus and the skin

Several dermatoses are routinely associated with diabetes mellitus, especially in patients with chronic disease. This relationship can be easily proven in some skin disorders, but it is not so clear in others. Dermatoses such necrobiosis lipoidica, granuloma annulare, acanthosis nigricans and others are discussed in this text, with an emphasis on proven link with the diabetes or not, disease identification and treatment strategy used to control those dermatoses and diabetes.

Hyperglycemia Induces Skin Barrier Dysfunctions with Impairment of Epidermal Integrity in Non-Wounded Skin of Type 1 Diabetic Mice

Diabetes causes skin complications, including xerosis and foot ulcers. Ulcers complicated by infections exacerbate skin conditions, and in severe cases, limb/toe amputations are required to prevent the development of sepsis. Here, we hypothesize that hyperglycemia induces skin barrier dysfunction with alterations of epidermal integrity. The effects of hyperglycemia on the epidermis were examined in streptozotocin-induced diabetic mice with/without insulin therapy. The results showed that dye leakages were prominent, and transepidermal water loss after tape stripping was exacerbated in diabetic mice. These data indicate that hyperglycemia impaired skin barrier functions. Additionally, the distribution of the protein associated with the tight junction structure, tight junction protein-1 (ZO-1), was characterized by diffuse and significantly wider expression in the diabetic mice compared to that in the control mice. In turn, epidermal cell number was significantly reduced and basal cells were irregularly aligned with ultrastructural alterations in diabetic mice. In contrast, the number of corneocytes, namely, denucleated and terminally differentiated keratinocytes significantly increased, while their sensitivity to mechanical stress was enhanced in the diabetic mice. We found that cell proliferation was significantly decreased, while apoptotic cells were comparable in the skin of diabetic mice, compared to those in the control mice. In the epidermis, Keratin 5 and keratin 14 expressions were reduced, while keratin 10 and loricrin were ectopically induced in diabetic mice. These data suggest that hyperglycemia altered keratinocyte proliferation/differentiation. Finally, these phenotypes observed in diabetic mice were mitigated by insulin treatment. Reduction in basal cell number and perturbation of the proliferation/differentiation process could be the underlying mechanisms for impaired skin barrier functions in diabetic mice.

The effect of an emollient with benfothiamine and Biolin prebiotic on the improvement of epidermal skin function

INTRODUCTION

Complications of diabetes can damage internal organs and the skin. Diabetic skin, irritated and dry, is susceptible to skin infections. However little is known about influence of emollients on biophysical changes in skin during diabetes.

AIM

To evaluate clinical skin changes after application of emollients with benfothiamine and Biolin prebiotic and to assess changes in biophysical parameters of the skin before and 4 weeks after daily application of an emollient.

MATERIAL AND METHODS

We recruited 50 patients with diabetes mellitus type 1 (DM1) or type 2 (DM2). All participants applied emollients on their left forearms and left shins for 4 weeks. The biophysical properties: pH, transepidermal water loss (TEWL), hydration of the stratum corneum and sebum content were measured and compared to those before enrollment to the study, after 1 h, 1 week and 4 weeks after application of an emollient.

RESULTS

After 4 weeks of treatment, there was an increase in skin hydration (40.61 ±19.03 vs. 48.83 ±15.51), pH (5.11 ±0.56 to 5.27 ±0.48) and sebum content (22.16 ±8.67 to 63.99 ±25.41) and a decrease in TEWL (12.54 ±5.6 vs. 9.85 ±5.69 g/m(2)/h) on forearms (p < 0.05 for all comparisons). On lower legs, significant changes in skin hydration (37.21 ±14.01 vs. 43.95 ±12.67), pH (5.04 ±0.57 to 5.31 ±0.49), sebum content (25.82 ±10.46 to 72.63 ±31.23) and TEWL (8.87 ±4.05 vs. 7.39 ±3.22 g/m(2)/h) were observed (p < 0.05 for all comparisons).

CONCLUSIONS

Our study provides an insight into changes in diabetic skin after application of an emollient. To our knowledge, this is the first report on the emollient containing benfothiamine and Biolin prebiotic and its influence on biophysical parameters of epidermis.

Skin disorders in diabetes mellitus: an epidemiology and physiopathology review

Skin disorders, usually neglected and frequently underdiagnosed among diabetic patients, are common complications and encounter a broad spectrum of disorders in both type 1 and type 2 diabetes mellitus (DM)-e.g. cutaneous infection, dry skin, pruritus. Skin disorders are highly associated with increased risk of important outcomes, such as skin lesions, ulcerations and diabetic foot, which can lead to major complications and revolve around multifactorial factors besides hyperglycemia and advanced glycation end products. Although diabetic's skin disorders are consistent in the literature, there is limited data regarding early-stage skin disorders in DM patients. Disease control, early-stage treatment (e.g. skin hydration, orthotic devices) and awareness can reduce morbidity of DM patients. Thus, better understanding of the burden of skin disorders in DM patients may raise awareness on prevention and management. Therefore, the aim of this study is to perform a literature review to evaluate the main clinical characteristics and complications of skin disorders in diabetic's patients. Additionally, physiopathology early-stage skin disorders and dermocosmetic management were also reviewed.

Diabetes Mellitus is Associated With Low Secretion Rates of Immunoglobulin A in Saliva

BACKGROUND

The association between diabetes mellitus (DM) and low secretory immunoglobulin A (s-IgA) secretion rates is one mechanism suspected of influencing susceptibility to infections among DM patients. However, several studies have shown contradictory results. We examined these two factors to seek evidence of an association among older people.

METHODS

We analyzed a prospective cohort of 2306 subjects (1209 men and 1097 women) around 64 years old from the New Integrated Suburban Seniority Investigation (NISSIN) Project in Nisshin, Japan. DM statuses were ascertained from levels of fasting plasma glucose and HbA1c, and s-IgA secretion rates were obtained from 5-min saliva samples. We used an analysis of covariance adjusted for possible confounders to compare s-IgA secretion rates according to DM status.

RESULTS

s-IgA secretion rates in DM participants were lower than in those classified as normal (18.6 µg/min vs 15.0 µg/min, P = 0.03), even after elimination of the effects of possible confounders.

CONCLUSIONS

DM was associated with lower s-IgA secretion rates. This suggests that lower s-IgA levels may be a mechanism of susceptibility to infection in individuals with DM.

Granuloma annulare and necrobiosis lipoidica with sequential occurrence in a patient: report and review of literature

Granuloma annulare (GA) and necrobiosis lipoidica (NL) are granulomatous diseases of undetermined etiology. Rarely, both dermatoses have been reported to occur concomitantly in patients. GA and NL are characterized histologically by areas of necrobiosis of collagen. The two diseases share some common characteristics, which may suggest that these dermatoses could occur as a spectrum in some patients or possibly share a similar pathogenesis. We report on a 67-year-old Caucasian woman with a history of NL on the anterior shins that later developed lesions of GA on the breasts, trunk, and wrist. We also review the literature and discuss the characteristics of patients with concomitant GA and NL.

A longitudinal study of foot ulceration and its risk factors in community-based patients with type 2 diabetes: the Fremantle Diabetes Study

AIMS

To determine the prevalence and associates of foot ulcer, and the subsequent incidence and predictors of first-ever hospitalisation for this complication, in well-characterised community-based patients with type 2 diabetes.

METHODS

Baseline foot ulceration was ascertained in 1296 patients (mean age 64 years, 48.6% male, median diabetes duration 4.0 years) recruited to the longitudinal Fremantle Diabetes Study between 1993 and 1996. Incident hospitalisation for foot ulceration was monitored through validated data linkage until end-December 2010.

RESULTS

At baseline, 16 participants (1.2%) had a foot ulcer which was independently associated with intermittent claudication, peripheral sensory neuropathy (PSN) and diabetes duration (P≤0.01). The incidence of hospitalisation for this complication in those without prior/prevalent foot ulceration was 5.21 per 1000 patient-years. This rate and other published data suggest that 1 in 7-10 foot ulcers require hospitalisation. In a Cox proportional hazards model, intermittent claudication and PSN were significant independent predictors of time to admission with foot ulceration, in addition to retinopathy, cerebrovascular disease, HbA1c, alcohol consumption, renal impairment, peripheral arterial disease and pulse pressure (P≤0.038).

CONCLUSIONS

These data confirm PSN as an important risk factor for foot ulceration but, in contrast to some other studies, peripheral arterial disease was also a major independent contributor. Associations between hospitalisation for foot ulcer and both retinopathy and raised pulse pressure suggest a role for local microvascular dysfunction, while alcohol may have non-neuropathic toxic effects on skin/subcutaneous structures. The multifactorial nature of foot ulceration complicating type 2 diabetes may have implications for its management.

High prevalence of cutaneous manifestations in the elderly with diabetes mellitus: an institution-based cross-sectional study in Taiwan

BACKGROUNDS

Diabetes mellitus (DM) is a common endocrine disorder and an increasing epidemic worldwide. Proportional diabetic patients eventually develop cutaneous diseases.

OBJECTIVES

This study determined the statistical association of cutaneous manifestations and DM as well as the DM-associated cutaneous manifestations in elderly male residents.

METHODS

A cross-sectional study was conducted in a Veterans Home in Taiwan. The cutaneous manifestations and major systemic diseases of the residents were recorded separately. Univariate logistic regression and multivariate analysis after adjustment for age, body mass index and significant major systemic diseases provided odds ratios and P values for the statistical association.

RESULTS

A total of 313 male residents (age ≥65 years) were recruited, including 70 (22.4%) with DM. Their most common cutaneous manifestations included fungal infection (77%) and brown spots on the legs (38.3%). Chronic ulcers adjusted odds ratios (AOR 4.90, 95%CI: 1.82-13.19; P = 0.002), brown spots on the legs (AOR 6.82, 95%CI: 3.60-12.89; P < 0.001) and pruritus (AOR 12.86, 95%CI: 4.40-37.59; P < 0.001) were significantly associated with DM. The diabetic residents were inclined to have chronic ulcers, brown spots on the legs and pruritus at a 7.46-fold higher risk (AOR 7.46, 95%CI: 3.86-14.43; P < 0.001). The diabetic residents exhibited marginally higher risks of bacterial infection, scabies, or skin tags.

CONCLUSION

The DM-associated cutaneous manifestations were chronic ulcers, brown spots on the legs, and pruritus. By observing clues of diabetic cutaneous features, a more complete condition of diabetic patients can be appreciated. The information is essential for providing appropriate treatment and key nursing points regarding the diabetes-associated skin diseases.

Cutaneous manifestations in children with diabetes mellitus and obesity

Obesity and diabetes are chronic diseases that affect people all over the world, and their incidence is increasing in both children and adults. Clinically, they affect a number of organs, including the skin. The cutaneous manifestations caused or aggravated by obesity and diabetes are varied and usually bear some relation to the time that has elapsed since the onset of the disease. They include soft fibromas, acanthosis nigricans, striae, xerosis, keratosis pilaris, plantar hyperkeratosis, fungal and bacterial skin infections, granuloma annulare, necrobiosis lipoidica, psoriasis, and atopic dermatitis. In this review article we present the skin changes found in children with diabetes mellitus and obesity and related syndromes and highlight the importance of the skin as a tool for establishing clinical suspicion and early diagnosis of systemic disease.

The sympathetic release test: a test used to assess thermoregulation and autonomic control of blood flow

When a subject is heated, the stimulation of temperature-sensitive nerve endings in the skin, and the raising of the central body temperature, results in the reflex release of sympathetic vasoconstrictor tone in the skin of the extremities, causing a measurable temperature increase at the site of release. In the sympathetic release test, the subject is gently heated by placing the feet and calves in a commercially available foot warming pouch or immersing the feet and calves in warm water and wrapping the subject in blankets. Skin blood flow is estimated from measurements of skin temperature in the fingers. Normally skin temperature of the fingers is 65-75°F in cool conditions (environmental temperature: 59-68°F) and rises to 85-95°F during body heating. Deviations in this pattern may mean that there is abnormal sympathetic vasoconstrictor control of skin blood flow. Abnormal skin blood flow can substantially impair an individual's ability to thermoregulate and has important clinical implications. During whole body heating, the skin temperature from three different skin sites is monitored and oral temperature is monitored as an index of core temperature. Students determine the fingertip temperature at which the reflex release of sympathetic activity occurs and its maximal attainment, which reflects the vasodilating capacity of this cutaneous vascular bed. Students should interpret typical sample data for certain clinical conditions (Raynaud's disease, peripheral vascular disease, and postsympathectomy) and explain why there may be altered skin blood flow in these disorders.

Relationship between skin diseases and extracutaneous complications of diabetes mellitus: clinical analysis of 750 patients

BACKGROUND

The relationship between skin diseases and extracutaneous complications in diabetes mellitus (DM) is unclear.

OBJECTIVE

We aimed to investigate the relationship between skin disorders and diabetic neuropathy, nephropathy, and retinopathy in patients with DM.

METHODS

A total of 750 patients with DM were prospectively enrolled. Demographic and clinical features, skin disorders, glycosylated hemoglobin (HbA1c) levels, and presence of nephropathy, neuropathy, and retinopathy were noted.

RESULTS

Of the patients, 38.0% had neuropathy, 23.3% had nephropathy, and 22.9% had retinopathy. Any skin disorder was present in 79.2% (n = 594) of patients. The most common skin manifestations were cutaneous infections (47.5%), xerosis (26.4%), and inflammatory skin diseases (20.7%). The frequency of cutaneous infections, fungal infections, diabetic foot, rubeosis faciei, and pigmented purpuric dermatitis was higher in patients with nephropathy than in those without nephropathy. Cutaneous infections, diabetic foot, rubeosis faciei, and diabetic dermopathy were more common in patients with neuropathy. Fungal infections, diabetic foot, rubeosis faciei, diabetic dermopathy, and pigmented purpuric dermatitis were more frequent in patients with retinopathy. Patients with HbA1c ≥8 mmol/mL had more skin disorders than those with HbA1c <8 mmol/mL (P < 0.05 for all).

CONCLUSION

Skin disorders may be clues to the presence of associated microvascular complications of DM.

Skin and diabetes mellitus: what do we know?

Diabetes mellitus (DM) is becoming increasingly prevalent worldwide. Although major complications of this condition involve kidney, retina and peripheral nerves, the skin of diabetic patients is also frequently injured. Hence, interest is mounting in the definition of the structural and molecular profile of non-complicated diabetic skin, i.e., before injuries occur. Most of the available knowledge in this area has been obtained relatively recently and, in part, derives from various diabetic animal models. These include both insulin-dependent and insulin-resistant models. Structural work in human diabetic skin has also been carried out by means of tissue samples or of non-invasive methods. Indications have indeed been found for molecular/structural changes in diabetic skin. However, the overall picture that emerges is heterogeneous, incomplete and often contradictory and many questions remain unanswered. This review aims to detail, as much as possible, the various pieces of current knowledge in a systematic and synoptic manner. This should aid the identification of areas in which key questions are still open and more research is needed. A comprehensive understanding of this field could help in determining molecular targets for the prevention and treatment of skin injuries in DM and markers for the monitoring of cutaneous and systemic aspects of the disease. Additionally, with the increasing development of non-invasive optics-based deep-tissue-imaging diagnostic technologies, precise knowledge of cutaneous texture and molecular structure becomes an important pre-requisite for the use of such methods in diabetic patients.

Dermatologic manifestations of diabetes mellitus: a review

Diabetes mellitus affects every organ of the body including the skin. Certain skin manifestations of diabetes are considered cutaneous markers of the disease, whereas others are nonspecific conditions that occur more frequently among individuals with diabetes compared with the general population. Diabetic patients have an increased susceptibility to some bacterial and fungal skin infections, which account, in part, for poor healing. Skin complications of diabetes provide clues to current and past metabolic status. Recognition of cutaneous markers may slow disease progression and ultimately improve the overall prognosis by enabling earlier diagnosis and treatment.

Dermatologic manifestation of diabetes

With the rising incidence of diabetes mellitus (DM) in the US, it is of paramount importance that practitioners understand the complications of DM and how best to manage them. Diabetes affects every organ system and the skin is no exception. There are numerous cutaneous manifestations of DM that have similar etiologies and result from the same pathologic mechanisms as the internal complications of this disease state. In addition, skin manifestations may precede the diagnosis of diabetes. The present article reviews both the common and less common cutaneous manifestations of DM, including presenting lesions, pathogenesis, and management.

Cutaneous sarcoidosis clinically mimicking necrobiosis lipoidica in a patient with systemic sarcoidosis

A 70-year-old woman with an 8-year history of systemic sarcoidosis developed round, red-brown eruptions, with central atrophic lesions on her lower legs. The features of the biopsy specimen resembled those of necrobiosis lipoidica (NL), but although necrobiosis was present there were well-formed non-necrotizing granulomas in the dermis. The histological diagnosis was cutaneous sarcoidosis. Systemic sarcoidosis presenting with NL has rarely been reported. The histological features of cutaneous sarcoidosis sometimes mimic those of other granulomatous diseases, including NL and granuloma annulare, which are difficult to distinguish. We discuss the novel association between sarcoidosis and other granulomatous diseases.

In vivo laser speckle imaging reveals microvascular remodeling and hemodynamic changes during wound healing angiogenesis

Laser speckle contrast imaging (LSCI) is a high-resolution and high contrast optical imaging technique often used to characterize hemodynamic changes in short-term physiological experiments. In this study, we demonstrate the utility of LSCI for characterizing microvascular remodeling and hemodynamic changes during wound healing angiogenesis in vivo. A 2 mm diameter hole was made in the mouse ear and the periphery of the wound imaged in vivo using LSCI over 12 days. We were able to visualize and quantify the vascular and perfusion changes that accompanied wound healing in the microenvironment proximal to the wound, and validated these changes with histology. We found that consistent with the stages of wound healing, microvessel density increased during the initial inflammatory phase (i.e., day 0-3), stayed elevated through the tissue formation phase (i.e., until day 7) and returned to baseline during the tissue remodeling phase (i.e., by day 12). Concomitant "wide area mapping" of blood flow revealed that tissue perfusion in the wound periphery initially decreased, gradually increased from day 3-7, and subsided as healing completed. Interestingly, some regions exhibited a reestablishment of tissue perfusion approximately 6 days earlier than the ~18 days usually reported for the long term remodeling phase. The results from this study demonstrate that LSCI is an ideal platform for elucidating in vivo changes in microvascular hemodynamics and angiogenesis, and has the potential to offer invaluable insights in a range of disease models involving abnormal hemodynamics, such as diabetes and tumors.

Necrobiosis lipoidica in diabetic patients: pathogenetic and clinical features

Necrobiosis lipoidica (NL) is a chronic skin disease (dermatosis) associated with various metabolic disorders including carbohydrate metabolism.In the last years, NL has been increasingly frequently diagnosed by practitioners probably due to the rise in type 2 diabetes mellitus morbidity in thegeneral population. Moreover, association of NL with autoimmune thyroid diseases, Crohns disease, ulcerative colitis, sarcoidosis, and vitiligo hasbeen documented. Such cases may be attributed to phenotypic and functional defects of cellular immunity.

Ciprofloxacin inhibits advanced glycation end products-induced adhesion molecule expression on human monocytes

BACKGROUND AND PURPOSE Advanced glycation end products (AGEs) subtypes, proteins or lipids that become glycated after exposure to sugars, can induce complications in diabetes. Among the various AGE subtypes, glyceraldehyde-derived AGE (AGE-2) and glycolaldehyde-derived AGE (AGE-3) are involved in inflammation in diabetic patients; monocytes are activated by these AGEs. Ciprofloxacin (CIP), a fluorinated 4-quinolone, is often used clinically to treat infections associated with diabetis due to its antibacterial properties. It also modulates immune responses in human peripheral blood mononuclear cells (PBMC) therefore we investigated the involvement of AGEs in these effects. EXPERIMENTAL APPROACH Expression of intercellular adhesion molecule (ICAM)-1, B7.1, B7.2 and CD40 was examined by flow cytometry. The production of tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma, prostaglandin E(2) (PGE(2)) and cAMP were determined by enzyme-linked immunosorbent assay. Cyclooxygenase (COX)-2 expression was determined by Western blot analysis. Lymphocyte proliferation was determined by [(3)H]-thymidine uptake. KEY RESULTS CIP induced PGE(2) production in monocytes, irrespective of the presence of AGE-2 and AGE-3, by enhancing COX-2 expression; this led to an elevation of intracellular cAMP in monocytes. Non-selective and selective COX-2 inhibitors, indomethacin and NS398, inhibited CIP-induced PGE(2) and cAMP production. In addition, CIP inhibited AGE-2- and AGE-3-induced expressions of ICAM-1, B7.1, B7.2 and CD40 in monocytes, the production of TNF-alpha and IFN-gamma and lymphocyte proliferation in PBMC. Indomethacin, NS398 and a protein kinase A inhibitor, H89, inhibited the actions of CIP. CONCLUSIONS AND IMPLICATIONS CIP exerts immunomodulatory activity via PGE(2), implying therapeutic potential of CIP for the treatment of AGE-2- and AGE-3-induced inflammatory responses.

Genetic and epigenetic events in diabetic wound healing

The prevalence of the chronic metabolic disorder, diabetes mellitus, is expected to increase in the coming years and worldwide pandemic levels are predicted. Inevitably, this will be accompanied by an increase in the prevalence of diabetic complications, including diabetic foot ulcers. At present, treatment options for diabetic foot ulcers are in many cases insufficient, and progression of the condition results in the requirement for limb amputation in a proportion of patients. To improve therapy, an increase in our understanding of the pathobiology of diabetic complications such as impaired wound healing is necessary. In this review, recent advances in molecular aspects of normal and impaired diabetic wound healing are discussed. Furthermore, investigations of the role of epigenetic processes in the pathogenesis of impaired diabetic wound healing are now emerging. Indeed, epigenetic changes have already been identified as key factors in diabetes and related complications and these are overviewed in this review.

Radiation-induced microenvironments--the molecular basis for free flap complications in the pre-irradiated field?

BACKGROUND AND PURPOSE

The effect of preoperative radio- or radiochemotherapy on the survival of free flaps used for head and neck reconstruction is reported in a contradictory way. Although there is a lot of knowledge on radiation-induced wound healing disorders from animal models there are no investigations on human patients so far. Our prospective study aimed at clarifying the effect of radiotherapy on clinically apparent free flap complications and on correlating them with radiation-induced extracellular matrix (ECM) remodeling.

MATERIALS AND METHODS

Healing of 114 free flaps was monitored in a prospective study and correlated with different anamnestic features, such as diabetes and radio- or radiochemotherapy using multivariate regression. During the operation connective tissue biopsies were harvested from the graft beds and analyzed for Transforming Growth Factor (TGF)-beta(1)-expression by means of Western blotting as well as Tissue Inhibitor of Matrix-Metallo-Proteinase (TIMP)-1 and Matrix-Metallo-Proteinase (MMP)-1 by immunohistochemistry.

RESULTS

History of radio- or radiochemotherapy was the only factor significantly predicting free flap complications. Radiochemotherapy resulted in a significant increase in TGF-beta(1)- and TIMP-1-expression, while MMP-1-expression was not significantly altered. Radiotherapy alone significantly increased TIMP-1-expression without detectable effects on TGF-beta(1) and MMP-1.

CONCLUSIONS

Radio- and radiochemotherapy alter graft bed ECM organization prior to surgery. This alteration impacts significantly on free flap survival in the pre-irradiated field.