Multilayered silicone foam dressings potentially used for preventing recurrence of pressure injuries: A bench-to-clinical bedside study.

AIM: This study aimed to evaluate the use of multilayered silicone foam dressings for preventing pressure injury recurrence by reducing friction, pressure, and shear force at skin sites where previous pressure injuries closed. METHODS: A bench-to-clinical bedside investigation was conducted. In the bench, three multilayered silicone foam dressings were assessed. The simulated skin-shearing test consisted of a weight, a polyurethane-based skin model containing a three-axis tactile sensor, dressings, a table covered with bedsheets, and a mechanical tester. The mechanical tester simultaneously measured the interface friction force and internal shear force and pressure continuously during skin model movements. No-dressing was used as a negative control. In clinical bedside assessments, a multilayered silicone foam dressing with lower friction and shear force was applied to two bedridden patients. Photographs and ultrasound images were used to assess the recurrence of pressure injury. RESULTS: The dressings significantly reduced friction, pressure, and shear force compared with these parameters in the negative control. No significant differences in the shear forces between the dressings were observed. One clinical case did not develop a new pressure injury reaching the dermis. However, the second case developed a new pressure injury within one month after the first pressure injury closed. CONCLUSION: Our bench-to-clinical bedside study revealed that multilayered silicone foam dressings can potentially prevent pressure injury recurrence.

Japanese clinical practice guidelines for aspiration and pharyngeal residual assessment during eating and swallowing for nursing care.

AIM: This clinical practice guideline aims to provide and recommend methods of assessing aspiration and pharyngeal residue during eating and swallowing and methods of selecting and implementing nursing care for adults to prevent the development of aspiration pneumonia through early and appropriate management of oropharyngeal dysphagia. METHODS: In April 2018, the Japan Academy of Nursing Science established the Supervisory Committee in Nursing Care Development/Standardization Committee to develop clinical practice guidelines for aspiration and pharyngeal residual assessment during eating and swallowing for nursing care. This clinical practice guideline was developed according to the Minds Manual for Guideline Development 2017, with the aim of providing a specific pathway for nurses to determine the policy for selecting management for oropharyngeal dysphagia based on research evidence and multifaceted factors including the balance of benefits and harms and patients' values. RESULTS: Based on the 10 clinical questions related to assessment by physical assessment, the Repetitive Saliva Swallowing Test, Modified Water Swallowing Test, Food Test, cervical auscultation, observation using an ultrasound diagnostic device, and an endoscope, 10 recommendations have been developed. Eight recommendations have been evaluated as the Grading of Recommendations Assessment, Development and Evaluation (GRADE) 2C, and the other two have been evaluated as no GRADE. CONCLUSION: The first reliable clinical practice guideline has been produced from an academic nursing organization that focuses on assessment for nursing care and incorporates the latest findings.

Increased temperature at the healed area detected by thermography predicts recurrent pressure ulcers.

Preventing recurrent pressure ulcers is an important challenge in healthcare. One of the reasons for the high rate of recurrent pressure ulcers is the lack of assessment methods for their early detection. Therefore, this study aimed to determine the thermographic characteristics of the healed area and to consider the predictive validity of thermographic images for recurrent pressure ulcers within a 2-week period. This observational study was conducted at a long-term care facility in Japan between July 2017 and February 2019 among patients whose pressure ulcers had healed. Thermographic images of the healed area were recorded once a week until recurrence or until the end of the study. We enrolled 30 participants, among whom 8 developed recurrent pressure ulcers. The generalised estimation equation revealed that the thermographic finding of increased temperature at the healed area compared to that of the surrounding skin was significantly associated with recurrent pressure ulcers (odds ratio: 101.13, 95% confidence interval: 3.60-2840.77, p = .007); the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio and negative likelihood ratio for recurrent pressure ulcers within 2 weeks were 0.80, 0.94, 0.62, 0.97, 12.9 and 0.2, respectively. Our thermographic findings revealed that the temperature of the healed area was higher than that of the surrounding skin; this could be a useful predictor of pressure ulcer recurrence within 2 weeks, even in the absence of macroscopic changes.

Diagnostic accuracy of ultrasound examination in detecting aspiration and pharyngeal residue in patients with dysphagia: A systematic review and meta-analysis.

AIM: To estimate diagnostic accuracy of ultrasonography for detecting aspiration and pharyngeal residue in patients with dysphagia. METHODS: A systematic search was conducted in MEDLINE (via PubMed), CINAHL, EMBASE, Ichushi-Web, and Cochrane Library databases to identify articles that showed diagnostic accuracy of ultrasonography for detecting aspiration and residue published in English and Japanese until August 2019. Cross-sectional studies, case-control studies, and cohort studies were included. The diagnostic accuracy results were extracted and the pooled estimated sensitivity and specificity were calculated. The risk of bias of the studies was assessed using the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies 2. The certainty of the evidence was assessed using the Grades of Recommendation Assessment, Development, and Evaluation methodology. RESULTS: Five studies were included in this review. The pooled estimated sensitivity and specificity for detecting aspiration were 0.82 (95% CI: 0.72-0.89) and 0.87 (95% CI: 0.81-0.92), respectively. One study was included that evaluated ultrasound assessments of pharyngeal residue. The sensitivity and specificity were 0.62 (95% CI: 0.32-0.86) and 0.67 (95% CI: 0.22-0.96), respectively. The certainty of the evidence was low and very low for the diagnostic accuracy of aspiration and pharyngeal residue, respectively. CONCLUSION: Ultrasound is a non-invasive method with good sensitivity and specificity in detecting aspiration as well as reference standards. While risk of bias and small number of studies limited the strength of this systematic review, our results suggested that ultrasound examination was useful as a bedside screening tool for detecting aspiration.

Risk scoring tool for forearm skin tears in Japanese older adults: A prospective cohort study.

[Aim] Because painful skin tears frequently occur in older patients, the prevention of skin tears is fundamental to improve their quality of life. However, a risk assessment tool for skin tears has not been established yet in Japan. Therefore, we aimed to propose a risk scoring tool for skin tears in Japanese older adult. [Methods] We conducted a prospective cohort study with 6-month follow-up in two long-term care hospitals in Japan. A total of 257 inpatients were recruited. Patient and skin characteristics were collected at baseline, and the occurrence of forearm skin tears were examined during follow-up. To develop a risk scoring tool, we identified risk factors, and converted their coefficients estimated in the multiple logistic regression analysis into simplified scores. The predictive accuracy of the total score was evaluated. [Results] Of 244 participants, 29 developed forearm skin tears during the follow-up period, a cumulative incidence of 13.5%. Senile purpura, pseudoscar, contracture, and dry skin were identified as risk factors for skin tears. Their weighted scores were 6, 4, 5, and 6, respectively. The area under the receiver operating characteristic curve of the total score was 0.806. At a cut-off score of 12, the sensitivity was 0.86, and the specificity was 0.67. [Conclusion] Our forearm skin tear risk scoring tool showed high accuracy, whereas specificity was low. This tool can contribute to prevent forearm skin tears in Japanese older adults.

Skin Physiology and its Microbiome as Factors Associated with the Recurrence of Pressure Injuries.

BACKGROUND: Preventing recurrent pressure injuries (RPIs) is one of the important challenges faced in healthcare, but the risk factors of RPIs have not been fully revealed. This study aims to explore factors associated with RPIs, by focusing on skin physiology and its microbiome as local factors crucial for the health of healed tissue after pressure injury healing. METHODS: This prospective observational study was conducted in a long-term care facility in Japan with patients whose PIs had healed within 1 month. Skin physiology was evaluated by stratum corneum (SC) hydration, pH, and transepidermal water loss. Skin bacteria was collected by tape stripping, followed by 16S ribosomal RNA-based metagenomics analysis. These parameters were evaluated every two weeks over a period of six weeks. RESULTS: A total of 30 patients were included in this study, and 8 patients (26.7%) had an RPI within 6 weeks. In this study, significantly lower SC hydration and a higher rate of Staphylococcus species on the healed site were found in the RPI group. DISCUSSION: A high rate of RPIs (about one in four) points out the necessity of a further care strategy on the healed PIs. Lower skin hydration and/or the increase in Staphylococcus bacteria may have a potential to be used as a biomarker for the prediction of RPIs, or may be an intervention point for the prevention of RPIs by, for example, skin cleansing with moisturizing care.

Stability of Skin Microbiome at Sacral Regions of Healthy Young Adults, Ambulatory Older Adults, and Bedridden Older Patients After 2 Years.

OBJECTIVE: The sacral skin of bedridden older patients often develops a dysbiotic condition. To clarify whether the condition changes or is sustained over time, we analyzed the skin microbiome and the skin physiological functions of the sacral skin in patients who completed our 2017 study. METHODS: In 2019, we collected the microbiome on the sacral region and measured sacral skin hydration, pH, and transepidermal water loss from 7 healthy young adults, 10 ambulatory older adults, and 8 bedridden older patients, all of whom had been recruited for the 2017 study. For microbiome analysis, 16S ribosomal RNA-based metagenomic analysis was used. RESULTS: No significant differences in the microbial compositions or any alpha diversity metrics were found in the bedridden older patients between the 2017 and 2019 studies; the higher gut-related bacteria were still observed on the sacral skin of the bedridden older patients even after 2 years. Only skin pH showed a significant decrease, approaching normal skin condition, in the bedridden older patients over 2 years. CONCLUSION: This study indicated that gut-related bacteria stably resided in the sacral skin in bedridden patients, even if the patient had tried to restore skin physiological functions using daily skin care. We propose the importance of skin care that focuses more on bacterial decontamination for the sacral region of bedridden older patients, in order to decrease the chances of skin/wound infection and inflammation.

Distinct Skin Microbiome and Skin Physiological Functions Between Bedridden Older Patients and Healthy People: A Single-Center Study in Japan.

With the increase in the older populations, the number of bedridden older patients is becoming a matter of concern. Skin microbiome and skin physiological functions are known to change according to lifestyle and community; however, such changes in case of movement- and cleaning-restricted bedridden older patients have not yet been revealed. To address this issue, we analyzed skin microbiome and skin physiological functions, including pH, hydration, sebum level, and transepidermal water loss (TEWL), of bedridden older patients, compared with those of ambulatory older and young individuals. For this analysis, we enrolled 19 healthy young and 18 ambulatory older individuals from the community and 31 bedridden older patients from a single, long-term care hospital in Japan. The area of interest was set to the sacral (lower back) skin, where pressure injuries (PIs) and subsequent infection frequently occurs in bedridden older patients. We observed a higher number of gut-related bacteria, fewer commensals, higher skin pH, and lower TEWL on the sacral skin of bedridden older patients than on that of young or ambulatory older individuals. In addition, we observed that 4 of the 31 bedridden older patients developed PIs during the research period; a higher abundance of pathogenic skin bacteria were also observed inside the PI wounds. These findings imply distinct skin microbiome and skin physiological functions in bedridden older patients in comparison with healthy individuals and may suggest the need for more stringent cleaning of the skin of bedridden older patients in light of the closeness of skin and wound microbiome.

Development of recurrent pressure ulcers, risk factors in older patients: a prospective observational study.

OBJECTIVE: Prevention of recurrent pressure ulcers (PU) is one of the most important challenges in wound care, furthermore, the risk factors for recurrent PUs are still not fully understood. This study aimed to explore the risk factors for recurrent PU development within two weeks, including biophysical skin properties, pro-inflammatory cytokine (tumour necrosis factor [TNF]-α) levels and bacterial species, in older patients. METHOD: This prospective study was conducted in a long-term care facility with patients whose PU had healed within two months. Biophysical skin properties were evaluated by stratum corneum hydration, pH, sebum content and transepidermal water loss. TNF-α level was measured using skin blotting. Skin bacteria were collected using tape stripping and determined by species-specific gene amplification. These parameters, along with Braden scale and interface pressure, were evaluated every two weeks for a total period of eight weeks. A penalised generalised estimating equation analysis was used to determine the risk factors for recurrent PUs. RESULTS: In total, 20 patients were included in this study, with 57 observations. Of these, recurrent PU was seen in eight observations. Elevation of pH (p=0.049; odds ratio [OR] per 1 unit=3.91, 95% confidence interval [CI]:1.01-15.15), presence of Acinetobacter spp. (p=0.039; OR versus culture-negative=6.28, 95%CI:1.10-35.86) and higher interface pressure (p=0.008; OR per 1 mmHg=1.06, 95%CI:1.01-1.10) on the healed PU were significantly related to the development of recurrent PU. CONCLUSION: Higher pH, existence of Acinetobacter spp. and higher interface pressure on the site of the healed PU were associated with the development of recurrent PUs in older patients undergoing conservative treatments.

Pre-collecting lymphatic vessels form detours following obstruction of lymphatic flow and function as collecting lymphatic vessels.

BACKGROUND: Previously, we showed that lymphatic vessels (LVs) formed detours after lymphatic obstruction, contributing to preventing lymphedema. In this study, we developed detours using lymphatic ligation in mice and we identified the detours histologically. METHODS AND RESULTS: Under anesthesia, both hindlimbs in mice were subcutaneously injected with Evans blue dye to detect LVs. We tied the right collecting LV on the abdomen that passes through the inguinal lymph node (LN) at two points. The right and left sides comprised the operation and sham operation sides, respectively. Lymphography was performed to investigate the lymph flow after lymphatic ligation until day 30, using a near-infrared fluorescence imaging system. Anti-podoplanin antibody and 5-ethynyl-2'-deoxyuridine (EdU) were used to detect LVs and lymphangiogenesis. Within 30 days, detours had developed in 62.5% of the mice. Detours observed between two ligation sites were enlarged and irregular in shape. Podoplanin+ LVs, which were located in the subcutaneous tissue of the upper panniculus carnosus muscle, connected to collecting LVs at the upper portion from the cranial ligation site and at the lower portion from the caudal ligation site. EdU+ cells were not observed in these detours. The sham operation side showed normal lymph flow and did not show enlarged pre-collecting LVs until day 30. CONCLUSIONS: Detours after lymphatic ligation were formed not by lymphangiogenesis but through an enlargement of pre-collecting LVs that functioned as collecting LVs after lymphatic ligation. Further studies are required to explore the developmental mechanism of the lymphatic detour for treatment and effective care of lymphedema in humans.

Safety of Venipuncture Sites at the Cubital Fossa as Assessed by Ultrasonography.

OBJECTIVE: The aim of the present observational study was to identify safe and suitable venipuncture sites for nursing in the clinical setting using ultrasonography to measure the depth and cross-sectional area of each superficial vein before and after tourniquet application as well as the distance between each superficial vein and the median nerve or brachial artery. METHODS AND RESULTS: Twenty healthy volunteers (21.8 [0.6] y) were recruited. The visible rate of each superficial vein before and after tourniquet application was 65% for the basilic vein, 90% to 95% for the median cubital vein, and 65% to 80% for the cephalic vein. The cross-sectional area of the median cubital vein after tourniquet application was significantly larger than that of the basilic vein and cephalic vein. The distance between the basilic vein or median cubital vein and median nerve was significantly smaller than that between the cephalic vein and median nerve. The distance between the basilic vein or median cubital vein and brachial artery was significantly smaller than that between the cephalic vein and brachial artery. CONCLUSIONS: These results demonstrated that the cephalic vein at the cubital fossa is a relatively safe venipuncture site because of its distance from the median nerve and brachial artery. When puncturing the cephalic vein is difficult because it is not visible, the median cubital vein at the cubital fossa may be selected for venipuncture due to its cross-sectional area and visibility; however, care is needed to avoid penetrating the vein because the median nerve and brachial artery are located underneath.

Prediction of healing in Category I pressure ulcers by skin blotting with plasminogen activator inhibitor 1, interleukin-1α, vascular endothelial growth factor C, and heat shock protein 90α: A pilot study.

The prevention of progression of Category I pressure ulcers (PUs) to Category II or higher is important, as Category II or higher PUs are open wounds and have a higher infection risk. Prognosis prediction of Category I PUs is necessary to provide successful intensive care for PUs with impaired healing. We focused on skin blotting using plasminogen activator inhibitor 1 (PAI1), interleukin-1α (IL-1α), vascular endothelial growth factor C (VEGF-C), and heat shock protein 90α (HSP90α). This pilot study was conducted at long-term-care and general hospitals to examine the applicability of DESIGN-R and thermography; the feasibility of skin blotting technique; the biomarker candidates, PAI1, IL-1α, VEGF-C, and HSP90α; and sample size for prognosis prediction for Category I PUs. Patients aged >65 years underwent skin blotting, scoring for DESIGN-R, and took thermography images of their Category I PU site. Albumin signals were not detected in one out of three participants. PAI1, IL-1α, VEGF-C, and HSP90α were detected in 19 participants, among whom 11 participants could be followed up after one week. There was no difference in DESIGN-R score and skin surface temperature between normal and impaired healing groups, and the sample size was calculated as 16. In conclusion, the feasibility of skin blotting was confirmed. PAI1, IL-1α, VEGF-C, and HSP90α could be biomarker candidates for prognosis prediction for Category I PU and the combination of VEGF-C and HSP90α could be associated with the prognosis of Category I PU. We need to investigate 842 patients in a future study.

Near-Infrared Fluorescence Imaging Directly Visualizes Lymphatic Drainage Pathways and Connections between Superficial and Deep Lymphatic Systems in the Mouse Hindlimb.

Since lymphedema rarely develops in the mouse hindlimb, the underlying mechanisms remain unclear. We herein investigated the resolution of chronic hindlimb lymphedema in mice using a Near-Infrared Fluorescence (NIRF) imaging system. Nineteen 7-28-week-old BALB/c male and female mice were injected with two dyes for lymphography and dissection. Lymphadenectomy was performed on six male mice to completely obstruct lymph flow in the hindlimb. Edematous changes in both hindlimbs were compared until 60 days after surgery. The NIRF imaging system detected three lymphatic collecting systems in the mouse hindlimb: superficial lateral, superficial medial, and deep medial. It also showed connections between the superficial and deep lymphatic systems in the inguinal region. Lymphadenectomy of the iliac, inguinal, and popliteal lymph nodes caused edematous changes. However, lymph flow in these operated areas restarted within 60 days and the severity of lymphedema appeared to be low. NIRF imaging showed that the deep medial system and a connection between the superficial and deep lymphatic systems in the inguinal region drain lymph from the hindlimb. This is the one reasons why lymphedema does not develop in the mouse hindlimb. The stable obstruction of lymph flow in these three systems is desired to develop chronic lymphedema.

Efficacy of Honeydew Honey and Blossom Honey on Full-thickness Wound Healing in Mice.

INTRODUCTION: The wound healing properties of honey, including blossom honey, are well known; however, the effects of honeydew honey during the wound healing process have not yet been investigated and thus remain unclear. OBJECTIVE: This study compares the effects of honeydew honey with those of blossom honey. MATERIALS AND METHODS: A total of 140 mice were divided into 2 control groups, which received either a hydrocolloid dressing (HCD; n = 22) or gauze (n = 22), and 4 experimental groups: honeydew honey (n = 23), Acacia honey (n = 23), Manuka honey (n = 22), and Japanese Pharmacopoeia honey (n = 28). Two circular full-thickness wounds were made and measured for 14 days. Each wound in the experimental groups was treated with 0.1 mL of honey and covered with gauze. Dressings in the control and experimental groups were changed daily. RESULTS: The wounds in all of the honey groups and the HCD group were moist by day 14, while those in the gauze group were dry. The ratio of wound area to initial wound area and the number of inflammatory cells decreased during the inflammatory phase in all honey groups. However, the honey groups exhibited reepithelialization rates of < 40%, numerous neutrophils, weak wound contraction, and impaired collagen deposition in wounds after day 11. CONCLUSIONS: These results suggest honeydew honey and blossom honey both exert anti-inflammatory effects during the inflammatory phase. However, all of the honeys examined were less effective at promoting full-thickness wound healing than the controls. Further studies are warranted.

Establishing a new appropriate intramuscular injection site in the deltoid muscle.

It is becoming increasingly important for clinicians to identify a safer intramuscular (IM) injection site in the deltoid muscle because of possible complications following the vaccine administration of IM injections. We herein examined 4 original IM sites located on the perpendicular line through the mid-acromion to establish a safer IM injection site. Thirty healthy volunteers participated in this study and the distances from our 4 IM sites to some anatomical landmarks on their left arms were measured. Ultrasonography (US) was also performed to measure the thickness of the deltoid muscle and identify the posterior circumflex humeral artery (PCHA) along the course of the axillary nerve. Subcutaneous thickness was measured using 2 methods: measuring the skin thickness with caliper after pinching the skin, and with US. The results obtained revealed that the intersection between the anteroposterior axillary line (the line between the upper end of the anterior axillary line and the upper end of the posterior axillary line) and the perpendicular line from the mid-acromion was the most appropriate site for IM injections because it was distant from the axillary nerve, PCHA, and subdeltoid/subacromial brusa. At this site, depth of needle insertions was 5 mm greater than the subcutaneous thickness at a 90° angle, which was sufficient to penetrate subcutaneous tissue in both sexes. Subcutaneous thickness can be assessed with almost the same accuracy by US or measuring with calipers after pinching the skin. The results of the present study support the improved vaccine practice for safer IM injections.

Lymph Drainage During Wound Healing in a Hindlimb Lymphedema Mouse Model.

BACKGROUND: Although lymphedematous skin exhibits delayed wound healing, little is known about lymph drainage during wound healing. We investigated the wound healing process in the presence of lymphatic dysfunction. METHODS AND RESULTS: The right inguinal lymph nodes (iLNs) and the surrounding tissue were excised in each mouse (the operation side), and a sham operation was performed in the left hindlimb (the control side). The next day, full-thickness wounds were made on both hindlimbs. The right hindlimb exhibited acute edema until day 3; however, it started to improve after day 4, and the wound area and epithelialization ratio were similar on both sides. Indocyanine green (ICG) was injected into both hindlimbs to observe lymph flow. On the operation side, ICG leaked out of the surgical site or remained at the injection site until day 2. Some lymph flow toward the existing lymph vessels was seen on day 3, and on day 10, lymph flow toward the axial LNs was detected on the operation side in all mice. On the operation side, the number of dermal lymph vessels was significantly increased on days 3 and 15. The dermal lymph vessel area of the peripheral wound was significantly smaller on the operation side. CONCLUSIONS: In a hindlimb lymphedema mouse model, lymph transiently accumulated in subcutaneous tissue, and then was gradually absorbed by the existing lymph vessels. The increase in the number of lymph vessels contributes to lymph drainage during wound healing. Acute lymphedema because of transient lymphatic dysfunction has little effect on wound healing.

Effectiveness of Changing the Application of Japanese Honey to a Hydrocolloid Dressing in Between the Inflammatory and Proliferative Phases on Cutaneous Wound Healing in Male Mice.

INTRODUCTION: The aim of this study was to investigate the effects of changing the application of Japanese honey to a hydrocolloid dressing (HCD) in between the inflammatory and proliferative phases on cutaneous wound healing in 8-week-old, BALB/cCrSlc male mice. MATERIALS AND METHODS: Mice were divided into 4 groups: acacia honey followed by a HCD, buckwheat flour honey followed by a HCD, Chinese milk vetch honey followed by a HCD, and a HCD alone (control group). All mice received 2 full-thickness wounds on both sides of the dorsum using a Disposable Biopsy Punch. The wounds of the control group were covered with a HCD, whereas wounds in the other groups were treated with 0.1 mL of the relevant type of honey until day 3 post-wound and then were covered with a HCD from days 4 to 14. RESULTS: In the experimental groups, the wound area ratio was significantly smaller in the inflammatory phase but significantly larger in the proliferative phase. Reepithelialization, collagen deposition, and wound contraction were significantly delayed compared with those in the control group. DISCUSSION: The re-expansion of the wounds in the proliferative phase could not be prevented, and reepithelialization, collagen deposition, and wound contraction were delayed compared with those upon the use of a HCD. CONCLUSION: The study's authors concluded that these methods do not promote cutaneous wound healing better than the use of a HCD alone.

Evaluation of Effects of Topical Estradiol Benzoate Application on Cutaneous Wound Healing in Ovariectomized Female Mice.

Estrogen promotes cutaneous wound healing in ovariectomized (OVX) female mice. However, the effects of topical estrogen application on wounds remain unclear. Therefore, the aim of this study was to compare the effects of topical estrogen application on wounds with standard treatment methods. Eight-week-old C57BL/6J female mice underwent OVX and received two full-thickness wounds four weeks later. Mice were divided into three groups: topical estradiol benzoate (EB) (0.75 µg/g/day) wound treatment, subcutaneous estradiol (E2) pellets (0.05 mg, 21 days), and topical E2 (0.01 g/day) skin application. Wound healing was observed until day 14. Wound area ratios were significantly smaller in the topical EB wound treatment group than in the subcutaneous E2 pellet group on days 1-14 (p < 0.05) and topical E2 skin application group on days 1-9 (p < 0.05). Neutrophil and macrophage numbers were significantly smaller in the topical EB wound treatment group than in the subcutaneous E2 pellet and topical E2 skin application groups on day 7 (p < 0.05). Moreover, the number of new blood vessels and ratio of myofibroblasts were significantly larger in the topical EB wound treatment group than in the subcutaneous E2 pellet and topical E2 application skin groups on day 7 (p < 0.05). These results demonstrate that the application of estrogen to wounds reduced inflammatory responses and promoted angiogenesis and wound contraction more than the two other standard treatment methods.

17ß-Estradiol administration promotes delayed cutaneous wound healing in 40-week ovariectomised female mice.

This study investigated the effect of 17ß-estradiol on wound healing in 40-week ovariectomised female mice. Thirty-six-week-old female mice were divided into three groups: medication with 17ß-estradiol after ovariectomy (OVX + 17ß-estradiol), ovariectomy (OVX) and sham (SHAM). The mice received two full-thickness wounds, and the OVX + 17ß-estradiol group was administered 17ß-estradiol at 0·01 g/day until healing. In the OVX + 17ß-estradiol group, the ratio of wound area was significantly smaller than those of the OVX and SHAM groups on days 1-3, 5, 6, 8-12 and 9-12, respectively, the numbers of neutrophils and macrophages were significantly smaller than those on days 3 and 7, the ratio of re-epithelialisation was significantly higher than those on days 3 and 11, the ratio of myofibroblasts was significantly higher than those on day 11 and smaller on day 14, and the ratio of collagen fibres was significantly larger than that of the OVX group on days 7-14. We found that 17ß-estradiol administration promotes cutaneous wound healing in 40-week female mice by reducing wound area, shortening inflammatory response, and promoting re-epithelialisation, collagen deposition and wound contraction. Our results suggest that cutaneous wound healing that is delayed because of ageing is promoted by exogenous and continuous 17ß-estradiol administration.

Evaluation of the effects of a combination of Japanese honey and hydrocolloid dressing on cutaneous wound healing in male mice.

The aim of this study was to evaluate the effect of the combined use of Japanese honey and hydrocolloid dressing (HCD) on cutaneous wound healing. Mice were divided into four groups: the Acacia (Japan) + HCD, Manuka (New Zealand) + HCD, Chinese milk vetch (Japan) + HCD, and HCD (control) groups. The mice received two full-thickness wounds. The wounds of the HCD group were covered with HCD, whereas those of the other groups were treated with 0.1 mL of the relevant type of honey, before being covered with HCD. Wound area was significantly smaller in the HCD group than in the Acacia + HCD and Manuka + HCD groups on day 13 and days 8-14, respectively. Moreover, compared with the HCD group, reepithelialization was delayed in the Acacia + HCD group and reepithelialization and collagen deposition were delayed in the Chinese milk vetch + HCD and Manuka + HCD groups. These results indicate that the combined use of Japanese honey and HCD does not promote cutaneous wound healing compared with the use of HCD alone. Thus, this method is probably not useful for promoting healing.