Makoto Oe

Ultrasonographic and thermographic screening for latent inflammation in diabetic foot callus

AIMS Inflammation within the diabetic foot callus may be an earliest, predicting symptom of foot ulcer developing later. The purpose of this study was to identify latent inflammation within the foot callus using thermography and ultrasonography, and to investigate relationship between the inflammatory findings in callus and presence or absence of diabetes. METHODS This was a cross-sectional study of 60 cases with asymptomatic foot callus; the 30 diabetic patients and the 30 non-diabetic matched volunteers. Inflammation was defined using physiological imaging techniques; as skin temperature elevation in thermography and low echoic lesion in ultrasonography. RESULTS Sixty-three and ninety-four calli were observed in the diabetic and non-diabetic groups, respectively. The inflammation signs were detected by both of the two techniques in 10% of the calli in the diabetic group. No inflammation was noted in the non-diabetic group (p=0.014). CONCLUSIONS The inflammation signs presented here were specifically observed in the diabetic group. We consider that the physiological imaging techniques may be valuable screening tools for potential risk of diabetic foot ulcers.

Evaluating the effect of the new incentive system for high-risk pressure ulcer patients on wound healing and cost-effectiveness: A cohort study

OBJECTIVE To evaluate the effectiveness and cost-effectiveness of new incentive system for pressure ulcer management, which focused on skilled nurse staffing in terms of rate of healing and medical costs. DESIGN, SETTING AND PARTICIPANTS A prospective cohort study included two types of groups: 39 institutions, which introduced the new incentive system, and 20 non-introduced groups (control). Sixty-seven patients suffering from severe pressure ulcers in the introduced group and 38 patients in the non-introduced group were included. Wound healing and medical costs were monitored weekly for three weeks by their skilled nurses in charge. MAIN OUTCOME MEASURES Healing status and related medical costs. RESULTS The introduced group showed significantly higher rate of healing compared with the control group at each weekly assessment. Multiple regression analysis revealed that the introduction of the new incentive system was independently associated with the faster healing rate (beta=3.44, P<.001). The budget impact analysis demonstrated that introducing this system could reduce cost of treating severe pressure ulcers by 1.776 billion yen per year. CONCLUSIONS The new incentive system for the management of pressure ulcers, which focused on staffing with skilled nurses can improve healing rate with reduced medical cost.

Aging enhances maceration-induced ultrastructural alteration of the epidermis and impairment of skin barrier function.

BACKGROUND Skin maceration is recognized as a risk factor for the development of certain skin lesions. In health care settings, incontinence-associated skin maceration is highly prevalent in the elderly. However, the effect of senescence on maceration has not been fully elucidated. OBJECTIVE To reveal the enhancement of the maceration-induced ultrastructural alteration and barrier function of the epidermis by aging. METHODS Skin maceration was reproduced by exposure to agarose gel in human and rat. The ultrastructural alterations in human and rat tissue were observed by transmission electron microscopy. The skin barrier function was evaluated by noninvasive methods in human, and by the transdermal penetration of small- and large-fluorescent molecules in rat. In order to reveal the effect of aging on the skin maceration, we compared these parameters between young and aged rats. RESULTS In macerated skin, we observed expansion of the interstices of the stratum corneum, spinosum, and basale of the epidermis; disruption of the intercellular lipid structure in the stratum corneum; a decreased number of cell processes in the stratum spinosum and basale. The transdermal penetration test in the rat using two types of fluorescein indicated that maceration disrupted skin barrier function. Furthermore, senescence-enhanced ultrastructural and functional alterations were revealed in the rodent studies. CONCLUSION This study demonstrates that aging enhances skin maceration. Considering that maceration is a risk factor for the skin damage, the development of technology to promote skin barrier recovery after maceration in the elderly is warranted.

Morphological pattern classification system for plantar thermography of patients with diabetes.

Background: A plantar temperature distribution can be obtained by thermography; however, the advantage has not been effectively utilized in the past. We previously proposed a classification method based on the angiosome concept, but the method was insufficient because it was too subjective and complicated for clinicians. In this study, we propose a new classification system of plantar forepart thermographic patterns using an image segmentation technique. Methods: A cross-sectional observational study was conducted including 32 healthy volunteers and 129 patients with diabetes mellitus (DM). Individual thermographic variations and trends were evaluated. A comparison was conducted between the patterns obtained by our previous angiosome-based research and the patterns found by the new classification system. Results: The system objectively found wider variations of the plantar forepart thermographic patterns in the patients with DM compared with those in the control subjects. In patients with DM, the system showed that the whole-high pattern was most frequent (46%), followed by the butterfly pattern (12%). In the control group, the butterfly pattern was most frequent (44%), followed by the whole-high pattern (19%). Both ankle and toe brachial indices were higher in feet with high temperature area in the inner side of the plantar. Conclusions: Thermographic patterns found by the new computer-based system were similar to those obtained in our previous subjective work. The classification system found forefoot-low pattern and tiptoe-low pattern objectively. The system based on infrared thermography will be a screening tool to assess circulatory status in daily foot care of patients with DM.

Comparison of characteristics and healing course of diabetic foot ulcers by etiological classification: Neuropathic, ischemic, and neuro-ischemic type

AIMS To identify differences in the characteristics of patients with diabetic foot ulcers (DFUs) according to their etiological classification and to compare their healing time. METHODS Over a 4.5-year period, 73 patients with DFUs were recruited. DFUs were etiologically classified as being of neuropathic, ischemic, or neuro-ischemic origin. Descriptive analyses were performed to characterize study subjects, foot-related factors, and healing outcome and time. Duration of healing was assessed using the Kaplan-Meier method. Healing time among the three types was compared using the log rank test. RESULTS The number of patients manifesting neuropathic, ischemic, and neuro-ischemic ulcers was 30, 20, and 14, respectively. Differences were identified for age, diabetes duration, body mass index, hypertension, and estimated glomerular filtration rate. Patients with neuro-ischemic ulcers had better ankle-brachial index, skin perfusion pressure (SPP), and transcutaneous oxygen pressure values compared to those with ischemic ulcers. The average time in which 50% of patients had healed wounds was 70, 113, and 233 days for neuropathic, neuro-ischemic, and ischemic ulcers, respectively. Main factors associated with healing were age and SPP values. CONCLUSIONS Based on the etiological ulcer type, DFU healing course and several patient factors differed. Failure to consider the differences in DFU etiology may have led to heterogeneity of results in previous studies on DFUs.

Screening for Osteomyelitis Using Thermography in Patients with Diabetic Foot

One of the most serious complications of diabetic foot (DF) is osteomyelitis, and early detection is important. To assess the validity of thermography to screen for osteomyelitis, we investigated thermographic findings in patients with both DF and osteomyelitis. The subjects were 18 diabetic patients with 20 occurrences of DF who visited a dermatology department at a hospital in Tokyo and underwent evaluation by magnetic resonance imaging (MRI) and thermography between June 2010 and July 2012. Osteomyelitis was identified by MRI. Thermographs were taken of the wounds and legs after bed rest of more than 15 minutes. Two wound management researchers evaluated the range of increased skin temperature. There were three types of distribution of increased skin temperature: the periwound, ankle, and knee patterns. Fisher’s exact test revealed that the ankle pattern was significantly more common in the group with osteomyelitis than in the group without osteomyelitis (). The positive predictive value was 100%, and the negative predictive value was 71.4%. Our results suggest that an area of increased skin temperature extending to the ankle can be a sign of osteomyelitis. Thermography might therefore be useful for screening for osteomyelitis in patients with DF.

Histopathology of Incontinence-Associated Skin Lesions: Inner Tissue Damage Due to Invasion of Proteolytic Enzymes and Bacteria in Macerated Rat Skin.

A common complication in patients with incontinence is perineal skin lesions, which are recognized as a form of dermatitis. In these patients, perineal skin is exposed to digestive enzymes and intestinal bacterial flora, as well as excessive water. The relative contributions of digestive enzymes and intestinal bacterial flora to skin lesion formation have not been fully shown. This study was conducted to reveal the process of histopathological changes caused by proteases and bacterial inoculation in skin maceration. For skin maceration, agarose gel containing proteases was applied to the dorsal skin of male Sprague-Dawley rats for 4 h, followed by Pseudomonas aeruginosa inoculation for 30 min. Macroscopic changes, histological changes, bacterial distribution, inflammatory response, and keratinocyte proliferation and differentiation were examined. Proteases induced digestion in the prickle cell layer of the epidermis, and slight bleeding in the papillary dermis and around hair follicles in the macerated skin without macroscopic evidence of erosion. Bacterial inoculation of the skin macerated by proteolytic solution resulted in the formation of bacteria-rich clusters comprising numerous microorganisms and inflammatory cells within the papillary dermis, with remarkable tissue damage around the clusters. Tissue damage expanded by day 2. On day 3, the proliferative keratinocyte layer was elongated from the bulge region of the hair follicles. Application of proteases and P. aeruginosa induced skin lesion formation internally without macroscopic erosion of the overhydrated area, suggesting that the histopathology might be different from regular dermatitis. The healing process of this lesion is similar to transepidermal elimination.

Elevated plantar pressure in diabetic patients and its relationship with their gait features

PURPOSE High plantar pressure is a major risk factor for diabetic foot ulcers. The relationship between plantar pressure and foot mobility has been investigated in some studies. However, when the foot is in motion, foot mobility is only a small feature of the gait. Therefore, we investigated relationship between high plantar pressure and gait and also studied the motion of the trunk. In addition, we investigated the relationship between gait and patient characteristics to identify patients at high-risk of developing diabetic foot ulcers. METHODS The relationships between elevated plantar pressure, gait features, and patient characteristics were analyzed. Plantar pressure distribution in the stance phase was divided on the four plantar segments. Elevated plantar pressure was defined as being more than the mean plus one standard deviation of the corresponding segment in non-diabetic subjects. Plantar pressure distribution was measured by an F-scan system, and gait features were measured using wireless motion sensors attached to the sacrum and feet. Patient characteristics were obtained from medical records or by interview. RESULTS Small roll and yaw motions of the body and yaw motion of the foot during the mid-stance phase were related to the elevated plantar pressure in 57 diabetic patients. Furthermore, these gait features were related to sensory neuropathy, diabetes duration, patient weight, toe-gap force, and ankle range of motion. CONCLUSION Given our findings, it may be possible to prevent diabetic foot ulcers by increasing foot motion during the mid-stance phase. Passive exercise aimed at expanding ankle range of motion in patients with sensory neuropathy or long-standing diabetes may assist in achieving this.

Shear Stress-Normal Stress (Pressure) Ratio Decides Forming Callus in Patients with Diabetic Neuropathy

Aim. Callus is a risk factor, leading to severe diabetic foot ulcer; thus, prevention of callus formation is important. However, normal stress (pressure) and shear stress associated with callus have not been clarified. Additionally, as new valuables, a shear stress-normal stress (pressure) ratio (SPR) was examined. The purpose was to clarify the external force associated with callus formation in patients with diabetic neuropathy. Methods. The external force of the 1st, 2nd, and 5th metatarsal head (MTH) as callus predilection regions was measured. The SPR was calculated by dividing shear stress by normal stress (pressure), concretely, peak values (SPR-p) and time integral values (SPR-i). The optimal cut-off point was determined. Results. Callus formation region of the 1st and 2nd MTH had high SPR-i rather than noncallus formation region. The cut-off value of the 1st MTH was 0.60 and the 2nd MTH was 0.50. For the 5th MTH, variables pertaining to the external forces could not be determined to be indicators of callus formation because of low accuracy. Conclusions. The callus formation cut-off values of the 1st and 2nd MTH were clarified. In the future, it will be necessary to confirm the effect of using appropriate footwear and gait training on lowering SPR-i.

Skin blotting: a noninvasive technique for evaluating physiological skin status.

OBJECTIVE: The skin performs important structural and physiological functions, and skin assessment represents an important step in identifying skin problems. Although noninvasive techniques for assessing skin status exist, no such techniques for monitoring its physiological status are available. This study aimed to develop a novel skin-assessment technique known as skin blotting, based on the leakage of secreted proteins from inside the skin following overhydration in mice. The applicability of this technique was further investigated in a clinical setting. DESIGN: Skin blotting involves 2 steps: collecting proteins by attaching a damp nitrocellulose membrane to the surface of the skin, and immunostaining the collected proteins. The authors implanted fluorescein-conjugated dextran (F-DEX)–containing agarose gels into mice and detected the tissue distribution of F-DEX under different blotting conditions. They also analyzed the correlations between inflammatory cytokine secretion and leakage following ultraviolet irradiation in mice and in relation to body mass index in humans. MAIN RESULTS: The F-DEX in mice was distributed in the deeper and shallower layers of skin and leaked through the transfollicular and transepidermal routes, respectively. Ultraviolet irradiation induced tumor necrosis factor secretion in the epidermis in mice, which was detected by skin blotting, whereas follicular tumor necrosis factor was associated with body mass index in obese human subjects. These results support the applicability of skin blotting for skin assessment. CONCLUSIONS: Skin blotting represents a noninvasive technique for assessing skin physiology and has potential as a predictive and diagnostic tool for skin disorders.